Project import

diff --git a/libcxx/.arcconfig b/libcxx/.arcconfig
new file mode 100644
index 0000000..6d07e82
--- /dev/null
+++ b/libcxx/.arcconfig

@@ -0,0 +1,4 @@
+{
+  "project_id" : "libcxx",
+  "conduit_uri" : "http://reviews.llvm.org/"
+}

diff --git a/libcxx/Android.bp b/libcxx/Android.bp
new file mode 100644
index 0000000..bf9ee58
--- /dev/null
+++ b/libcxx/Android.bp

@@ -0,0 +1,110 @@
+//
+// Copyright (C) 2014 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+// host + device static lib
+cc_library_static {
+    host_supported: true,
+    name: "libc++_static",
+    clang: true,
+    srcs: [
+        "src/algorithm.cpp",
+        "src/any.cpp",
+        "src/bind.cpp",
+        "src/chrono.cpp",
+        "src/condition_variable.cpp",
+        "src/debug.cpp",
+        "src/exception.cpp",
+        "src/future.cpp",
+        "src/hash.cpp",
+        "src/ios.cpp",
+        "src/iostream.cpp",
+        "src/locale.cpp",
+        "src/memory.cpp",
+        "src/mutex.cpp",
+        "src/new.cpp",
+        "src/optional.cpp",
+        "src/random.cpp",
+        "src/regex.cpp",
+        "src/shared_mutex.cpp",
+        "src/stdexcept.cpp",
+        "src/string.cpp",
+        "src/strstream.cpp",
+        "src/system_error.cpp",
+        "src/thread.cpp",
+        "src/typeinfo.cpp",
+        "src/utility.cpp",
+        "src/valarray.cpp",
+    ],
+    local_include_dirs: ["include"],
+    export_include_dirs: ["include"],
+    cppflags: [
+        "-std=c++14",
+        "-nostdinc++",
+        "-fexceptions",
+        "-DLIBCXX_BUILDING_LIBCXXABI",
+    ],
+    rtti: true,
+    whole_static_libs: [
+        "libc++abi",
+    ],
+    stl: "none",
+}
+
+// host + device dynamic lib
+cc_library_shared {
+    host_supported: true,
+    name: "libc++",
+    clang: true,
+    whole_static_libs: ["libc++_static"],
+    stl: "none",
+
+    target: {
+        android: {
+            shared_libs: ["libdl"],
+        },
+        android_arm: {
+            static_libs: ["libunwind_llvm"],
+            ldflags: ["-Wl,--exclude-libs,libunwind_llvm.a"],
+        },
+        host: {
+            ldflags: ["-nodefaultlibs"],
+        },
+        darwin: {
+            unexported_symbols_list: "lib/libc++unexp.exp",
+            force_symbols_not_weak_list: "lib/notweak.exp",
+            force_symbols_weak_list: "lib/weak.exp",
+        },
+
+        linux: {
+            host_ldlibs: [
+                "-lrt",
+                "-lpthread",
+                "-ldl",
+            ],
+        },
+    },
+}
+
+
+// ANDROIDMK TRANSLATION ERROR: unsupported conditional
+// ifdef LIBCXX_TESTING
+// ANDROIDMK TRANSLATION ERROR: unsupported include
+// include $(LOCAL_PATH)/buildcmds/Android.mk
+
+// ANDROIDMK TRANSLATION ERROR: endif from unsupported contitional
+// endif
+// TARGET_BUILD_APPS
+

diff --git a/libcxx/Android.mk b/libcxx/Android.mk
new file mode 100644
index 0000000..f10c507
--- /dev/null
+++ b/libcxx/Android.mk

@@ -0,0 +1 @@
+# This empty Android.mk file is required to shadow buildcmds/Android.mk

diff --git a/libcxx/CMakeLists.txt b/libcxx/CMakeLists.txt
new file mode 100644
index 0000000..be6fbbe
--- /dev/null
+++ b/libcxx/CMakeLists.txt

@@ -0,0 +1,293 @@
+# See www/CMake.html for instructions on how to build libcxx with CMake.
+
+#===============================================================================
+# Setup Project
+#===============================================================================
+cmake_minimum_required(VERSION 2.8)
+
+if(POLICY CMP0042)
+  cmake_policy(SET CMP0042 NEW) # Set MACOSX_RPATH=YES by default
+endif()
+if(POLICY CMP0022)
+  cmake_policy(SET CMP0022 NEW) # Required when interacting with LLVM and Clang
+endif()
+
+project(libcxx CXX C)
+
+set(PACKAGE_NAME libcxx)
+set(PACKAGE_VERSION trunk-svn)
+set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
+set(PACKAGE_BUGREPORT "llvm-bugs@lists.llvm.org")
+
+# Add path for custom modules
+set(CMAKE_MODULE_PATH
+  "${CMAKE_CURRENT_SOURCE_DIR}/cmake"
+  "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules"
+  ${CMAKE_MODULE_PATH}
+  )
+
+# Require out of source build.
+include(MacroEnsureOutOfSourceBuild)
+MACRO_ENSURE_OUT_OF_SOURCE_BUILD(
+ "${PROJECT_NAME} requires an out of source build. Please create a separate
+ build directory and run 'cmake /path/to/${PROJECT_NAME} [options]' there."
+ )
+
+# Find the LLVM sources and simulate LLVM CMake options.
+include(HandleOutOfTreeLLVM)
+if (LIBCXX_BUILT_STANDALONE AND NOT LLVM_FOUND)
+  message(WARNING "UNSUPPORTED LIBCXX CONFIGURATION DETECTED: "
+                  "llvm-config not found and LLVM_PATH not defined.\n"
+                  "Reconfigure with -DLLVM_CONFIG=path/to/llvm-config "
+                  "or -DLLVM_PATH=path/to/llvm-source-root.")
+endif()
+
+
+#===============================================================================
+# Setup CMake Options
+#===============================================================================
+
+# Basic options ---------------------------------------------------------------
+option(LIBCXX_ENABLE_ASSERTIONS "Enable assertions independent of build mode." ON)
+option(LIBCXX_ENABLE_SHARED "Build libc++ as a shared library." ON)
+
+option(LIBCXX_INCLUDE_TESTS "Build the libc++ tests." ${LLVM_INCLUDE_TESTS})
+set(LIBCXX_LIBDIR_SUFFIX "${LLVM_LIBDIR_SUFFIX}" CACHE STRING
+    "Define suffix of library directory name (32/64)")
+option(LIBCXX_INSTALL_HEADERS "Install the libc++ headers." ON)
+option(LIBCXX_INSTALL_SUPPORT_HEADERS "Install libc++ support headers." ON)
+
+# ABI Library options ---------------------------------------------------------
+set(LIBCXX_CXX_ABI "${LIBCXX_CXX_ABI}" CACHE STRING
+    "Specify C++ ABI library to use." FORCE)
+set(CXXABIS none libcxxabi libcxxrt libstdc++ libsupc++)
+set_property(CACHE LIBCXX_CXX_ABI PROPERTY STRINGS ;${CXXABIS})
+
+option(LIBCXX_ENABLE_STATIC_ABI_LIBRARY "Statically link the ABI library" OFF)
+
+# Build libc++abi with libunwind. We need this option to determine whether to
+# link with libunwind or libgcc_s while running the test cases.
+option(LIBCXXABI_USE_LLVM_UNWINDER "Build and use the LLVM unwinder." OFF)
+
+# Target options --------------------------------------------------------------
+option(LIBCXX_BUILD_32_BITS "Build 32 bit libc++." ${LLVM_BUILD_32_BITS})
+set(LIBCXX_SYSROOT "" CACHE STRING "Use alternate sysroot.")
+set(LIBCXX_GCC_TOOLCHAIN "" CACHE STRING "Use alternate GCC toolchain.")
+
+# Feature options -------------------------------------------------------------
+option(LIBCXX_ENABLE_EXCEPTIONS "Use exceptions." ON)
+option(LIBCXX_ENABLE_RTTI "Use run time type information." ON)
+option(LIBCXX_ENABLE_GLOBAL_FILESYSTEM_NAMESPACE "Build libc++ with support for the global filesystem namespace." ON)
+option(LIBCXX_ENABLE_STDIN "Build libc++ with support for stdin/std::cin." ON)
+option(LIBCXX_ENABLE_STDOUT "Build libc++ with support for stdout/std::cout." ON)
+option(LIBCXX_ENABLE_THREADS "Build libc++ with support for threads." ON)
+option(LIBCXX_ENABLE_THREAD_UNSAFE_C_FUNCTIONS "Build libc++ with support for thread-unsafe C functions" ON)
+option(LIBCXX_ENABLE_MONOTONIC_CLOCK
+  "Build libc++ with support for a monotonic clock.
+   This option may only be used when LIBCXX_ENABLE_THREADS=OFF." ON)
+
+# Misc options ----------------------------------------------------------------
+option(LIBCXX_ENABLE_PEDANTIC "Compile with pedantic enabled." ON)
+option(LIBCXX_ENABLE_WERROR "Fail and stop if a warning is triggered." OFF)
+
+option(LIBCXX_GENERATE_COVERAGE "Enable generating code coverage." OFF)
+set(LIBCXX_COVERAGE_LIBRARY "" CACHE STRING
+    "The Profile-rt library used to build with code coverage")
+
+#===============================================================================
+# Check option configurations
+#===============================================================================
+
+# Ensure LIBCXX_ENABLE_MONOTONIC_CLOCK is set to ON only when
+# LIBCXX_ENABLE_THREADS is on.
+if(LIBCXX_ENABLE_THREADS AND NOT LIBCXX_ENABLE_MONOTONIC_CLOCK)
+  message(FATAL_ERROR "LIBCXX_ENABLE_MONOTONIC_CLOCK can only be set to OFF"
+                      " when LIBCXX_ENABLE_THREADS is also set to OFF.")
+endif()
+
+# Ensure LLVM_USE_SANITIZER is not specified when LIBCXX_GENERATE_COVERAGE
+# is ON.
+if (LLVM_USE_SANITIZER AND LIBCXX_GENERATE_COVERAGE)
+  message(FATAL_ERROR "LLVM_USE_SANITIZER cannot be used with LIBCXX_GENERATE_COVERAGE")
+endif()
+
+# Set LIBCXX_BUILD_32_BITS to (LIBCXX_BUILD_32_BITS OR LLVM_BUILD_32_BITS)
+# and check that we can build with 32 bits if requested.
+if (CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT WIN32)
+  if (LIBCXX_BUILD_32_BITS AND NOT LLVM_BUILD_32_BITS) # Don't duplicate the output from LLVM
+    message(STATUS "Building 32 bits executables and libraries.")
+  endif()
+elseif(LIBCXX_BUILD_32_BITS)
+  message(FATAL_ERROR "LIBCXX_BUILD_32_BITS=ON is not supported on this platform.")
+endif()
+
+# Check that this option is not enabled on Apple and emit a usage warning.
+if (LIBCXX_ENABLE_STATIC_ABI_LIBRARY)
+  if (APPLE)
+    message(FATAL_ERROR "LIBCXX_ENABLE_STATIC_ABI_LIBRARY is not supported on OS X")
+  else()
+    message(WARNING "LIBCXX_ENABLE_STATIC_ABI_LIBRARY is an experimental option")
+  endif()
+endif()
+
+#===============================================================================
+# Configure System
+#===============================================================================
+
+set(LIBCXX_COMPILER    ${CMAKE_CXX_COMPILER})
+set(LIBCXX_SOURCE_DIR  ${CMAKE_CURRENT_SOURCE_DIR})
+set(LIBCXX_BINARY_DIR  ${CMAKE_CURRENT_BINARY_DIR})
+set(LIBCXX_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LIBCXX_LIBDIR_SUFFIX})
+
+set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${LIBCXX_LIBRARY_DIR})
+set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${LIBCXX_LIBRARY_DIR})
+
+# Declare libc++ configuration variables.
+# They are intended for use as follows:
+# LIBCXX_CXX_FLAGS: General flags for both the compiler and linker.
+# LIBCXX_COMPILE_FLAGS: Compile only flags.
+# LIBCXX_LINK_FLAGS: Linker only flags.
+set(LIBCXX_COMPILE_FLAGS "")
+set(LIBCXX_LINK_FLAGS "")
+set(LIBCXX_LIBRARIES "")
+
+# Configure compiler.
+include(config-ix)
+
+# Configure coverage options.
+if (LIBCXX_GENERATE_COVERAGE)
+  include(CodeCoverage)
+  set(CMAKE_BUILD_TYPE "COVERAGE" CACHE STRING "" FORCE)
+endif()
+
+string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
+
+#===============================================================================
+# Setup Compiler Flags
+#===============================================================================
+
+include(HandleLibCXXABI) # Steup the ABI library flags
+
+# Include macros for adding and removing libc++ flags.
+include(HandleLibcxxFlags)
+
+# Remove flags that may have snuck in.
+remove_flags(-DNDEBUG -UNDEBUG -D_DEBUG
+             -stdlib=libc++ -stdlib=libstdc++ -lc++abi -m32)
+
+# Required flags ==============================================================
+add_compile_flags_if_supported(-std=c++11)
+if (NOT MSVC AND NOT LIBCXX_SUPPORTS_STD_EQ_CXX11_FLAG)
+  message(FATAL_ERROR "C++11 is required but the compiler does not support -std=c++11")
+endif()
+
+# On all systems the system c++ standard library headers need to be excluded.
+# MSVC only has -X, which disables all default includes; including the crt.
+# Thus, we do nothing and hope we don't accidentally include any of the C++
+# headers
+add_compile_flags_if_supported(-nostdinc++)
+
+# Target flags ================================================================
+add_flags_if(LIBCXX_BUILD_32_BITS -m32)
+add_flags_if(LIBCXX_TARGET_TRIPLE "-target ${LIBCXX_TARGET_TRIPLE}")
+add_flags_if(LIBCXX_SYSROOT "--sysroot ${LIBCXX_SYSROOT}")
+add_flags_if(LIBCXX_GCC_TOOLCHAIN "-gcc-toolchain ${LIBCXX_GCC_TOOLCHAIN}")
+
+# Warning flags ===============================================================
+add_definitions(-D_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+add_compile_flags_if_supported(
+    -Wall -W -Wwrite-strings
+    -Wno-unused-parameter -Wno-long-long
+    -Werror=return-type)
+if (LIBCXX_ENABLE_WERROR)
+  add_compile_flags_if_supported(-Werror)
+  add_compile_flags_if_supported(-WX)
+else()
+  # TODO(EricWF) Remove this. We shouldn't be suppressing errors when -Werror is
+  # added elsewhere.
+  add_compile_flags_if_supported(-Wno-error)
+endif()
+if (LIBCXX_ENABLE_PEDANTIC)
+  add_compile_flags_if_supported(-pedantic)
+endif()
+
+# Exception flags =============================================================
+if (LIBCXX_ENABLE_EXCEPTIONS)
+  # Catches C++ exceptions only and tells the compiler to assume that extern C
+  # functions never throw a C++ exception.
+  add_compile_flags_if_supported(-EHsc)
+else()
+  add_definitions(-D_LIBCPP_NO_EXCEPTIONS)
+  add_compile_flags_if_supported(-EHs- -EHa-)
+  add_compile_flags_if_supported(-fno-exceptions)
+endif()
+
+# RTTI flags ==================================================================
+if (NOT LIBCXX_ENABLE_RTTI)
+  add_definitions(-D_LIBCPP_NO_RTTI)
+  add_compile_flags_if_supported(-GR-)
+  add_compile_flags_if_supported(-fno-rtti)
+endif()
+
+# Assertion flags =============================================================
+define_if(LIBCXX_ENABLE_ASSERTIONS -UNDEBUG)
+define_if_not(LIBCXX_ENABLE_ASSERTIONS -DNDEBUG)
+if (LIBCXX_ENABLE_ASSERTIONS)
+  # MSVC doesn't like _DEBUG on release builds. See PR 4379.
+  define_if_not(MSVC -D_DEBUG)
+endif()
+
+# Feature flags ===============================================================
+define_if(MSVC -D_CRT_SECURE_NO_WARNINGS)
+define_if_not(LIBCXX_ENABLE_GLOBAL_FILESYSTEM_NAMESPACE -D_LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE)
+define_if_not(LIBCXX_ENABLE_STDIN -D_LIBCPP_HAS_NO_STDIN)
+define_if_not(LIBCXX_ENABLE_STDOUT -D_LIBCPP_HAS_NO_STDOUT)
+define_if_not(LIBCXX_ENABLE_THREADS -D_LIBCPP_HAS_NO_THREADS)
+define_if_not(LIBCXX_ENABLE_MONOTONIC_CLOCK -D_LIBCPP_HAS_NO_MONOTONIC_CLOCK)
+define_if_not(LIBCXX_ENABLE_THREAD_UNSAFE_C_FUNCTIONS -D_LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS)
+
+
+# Sanitizer flags
+
+# Configure for sanitizers. If LIBCXX_BUILT_STANDALONE then we have to do
+# the flag translation ourselves. Othewise LLVM's CMakeList.txt will handle it.
+if (LIBCXX_BUILT_STANDALONE)
+  set(LLVM_USE_SANITIZER "" CACHE STRING
+      "Define the sanitizer used to build the library and tests")
+  # NOTE: LLVM_USE_SANITIZER checks for a UNIX like system instead of MSVC.
+  # But we don't have LLVM_ON_UNIX so checking for MSVC is the best we can do.
+  if (LLVM_USE_SANITIZER AND NOT MSVC)
+    add_flags_if_supported("-fno-omit-frame-pointer")
+    add_flags_if_supported("-gline-tables-only")
+
+    if (NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "DEBUG" AND
+        NOT uppercase_CMAKE_BUILD_TYPE STREQUAL "RELWITHDEBINFO")
+        add_flags_if_supported("-gline-tables-only")
+    endif()
+    if (LLVM_USE_SANITIZER STREQUAL "Address")
+      add_flags("-fsanitize=address")
+    elseif (LLVM_USE_SANITIZER MATCHES "Memory(WithOrigins)?")
+      add_flags(-fsanitize=memory)
+      if (LLVM_USE_SANITIZER STREQUAL "MemoryWithOrigins")
+        add_flags("-fsanitize-memory-track-origins")
+      endif()
+    elseif (LLVM_USE_SANITIZER STREQUAL "Undefined")
+      add_flags("-fsanitize=undefined -fno-sanitize=vptr,function -fno-sanitize-recover=all")
+    elseif (LLVM_USE_SANITIZER STREQUAL "Thread")
+      add_flags(-fsanitize=thread)
+    else()
+      message(WARNING "Unsupported value of LLVM_USE_SANITIZER: ${LLVM_USE_SANITIZER}")
+    endif()
+  elseif(LLVM_USE_SANITIZER AND MSVC)
+    message(WARNING "LLVM_USE_SANITIZER is not supported on this platform.")
+  endif()
+endif()
+#===============================================================================
+# Setup Source Code And Tests
+#===============================================================================
+include_directories(include)
+add_subdirectory(include)
+add_subdirectory(lib)
+if (LIBCXX_INCLUDE_TESTS)
+  add_subdirectory(test)
+endif()

diff --git a/libcxx/CREDITS.TXT b/libcxx/CREDITS.TXT
new file mode 100644
index 0000000..1cf713a
--- /dev/null
+++ b/libcxx/CREDITS.TXT

@@ -0,0 +1,138 @@
+This file is a partial list of people who have contributed to the LLVM/libc++
+project.  If you have contributed a patch or made some other contribution to
+LLVM/libc++, please submit a patch to this file to add yourself, and it will be
+done!
+
+The list is sorted by surname and formatted to allow easy grepping and
+beautification by scripts.  The fields are: name (N), email (E), web-address
+(W), PGP key ID and fingerprint (P), description (D), and snail-mail address
+(S).
+
+N: Saleem Abdulrasool
+E: compnerd@compnerd.org
+D: Minor patches and Linux fixes.
+
+N: Dan Albert
+E: danalbert@google.com
+D: Android support and test runner improvements.
+
+N: Dimitry Andric
+E: dimitry@andric.com
+D: Visibility fixes, minor FreeBSD portability patches.
+
+N: Holger Arnold
+E: holgerar@gmail.com
+D: Minor fix.
+
+N: Ruben Van Boxem
+E: vanboxem dot ruben at gmail dot com
+D: Initial Windows patches.
+
+N: David Chisnall
+E: theraven at theravensnest dot org
+D: FreeBSD and Solaris ports, libcxxrt support, some atomics work.
+
+N: Marshall Clow
+E: mclow.lists@gmail.com
+E: marshall@idio.com
+D: C++14 support, patches and bug fixes.
+
+N: Eric Fiselier
+E: eric@efcs.ca
+D: LFTS support, patches and bug fixes.
+
+N: Bill Fisher
+E: william.w.fisher@gmail.com
+D: Regex bug fixes.
+
+N: Matthew Dempsky
+E: matthew@dempsky.org
+D: Minor patches and bug fixes.
+
+N: Google Inc.
+D: Copyright owner and contributor of the CityHash algorithm
+
+N: Howard Hinnant
+E: hhinnant@apple.com
+D: Architect and primary author of libc++
+
+N: Hyeon-bin Jeong
+E: tuhertz@gmail.com
+D: Minor patches and bug fixes.
+
+N: Argyrios Kyrtzidis
+E: kyrtzidis@apple.com
+D: Bug fixes.
+
+N: Bruce Mitchener, Jr.
+E: bruce.mitchener@gmail.com
+D: Emscripten-related changes.
+
+N: Michel Morin
+E: mimomorin@gmail.com
+D: Minor patches to is_convertible.
+
+N: Andrew Morrow
+E: andrew.c.morrow@gmail.com
+D: Minor patches and Linux fixes.
+
+N: Arvid Picciani
+E: aep at exys dot org
+D: Minor patches and musl port.
+
+N: Bjorn Reese
+E: breese@users.sourceforge.net
+D: Initial regex prototype
+
+N: Nico Rieck
+E: nico.rieck@gmail.com
+D: Windows fixes
+
+N: Jon Roelofs
+E: jonathan@codesourcery.com
+D: Remote testing, Newlib port, baremetal/single-threaded support.
+
+N: Jonathan Sauer
+D: Minor patches, mostly related to constexpr
+
+N: Craig Silverstein
+E: csilvers@google.com
+D: Implemented Cityhash as the string hash function on 64-bit machines
+
+N: Richard Smith
+D: Minor patches.
+
+N: Joerg Sonnenberger
+E: joerg@NetBSD.org
+D: NetBSD port.
+
+N: Stephan Tolksdorf
+E: st@quanttec.com
+D: Minor <atomic> fix
+
+N: Michael van der Westhuizen
+E: r1mikey at gmail dot com
+
+N: Larisse Voufo
+D: Minor patches.
+
+N: Klaas de Vries
+E: klaas at klaasgaaf dot nl
+D: Minor bug fix.
+
+N: Zhang Xiongpang
+E: zhangxiongpang@gmail.com
+D: Minor patches and bug fixes.
+
+N: Xing Xue
+E: xingxue@ca.ibm.com
+D: AIX port
+
+N: Zhihao Yuan
+E: lichray@gmail.com
+D: Standard compatibility fixes.
+
+N: Jeffrey Yasskin
+E: jyasskin@gmail.com
+E: jyasskin@google.com
+D: Linux fixes.

diff --git a/libcxx/LICENSE.TXT b/libcxx/LICENSE.TXT
new file mode 100644
index 0000000..53352e4
--- /dev/null
+++ b/libcxx/LICENSE.TXT

@@ -0,0 +1,76 @@
+==============================================================================
+libc++ License
+==============================================================================
+
+The libc++ library is dual licensed under both the University of Illinois
+"BSD-Like" license and the MIT license.  As a user of this code you may choose
+to use it under either license.  As a contributor, you agree to allow your code
+to be used under both.
+
+Full text of the relevant licenses is included below.
+
+==============================================================================
+
+University of Illinois/NCSA
+Open Source License
+
+Copyright (c) 2009-2015 by the contributors listed in CREDITS.TXT
+
+All rights reserved.
+
+Developed by:
+
+    LLVM Team
+
+    University of Illinois at Urbana-Champaign
+
+    http://llvm.org
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal with
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+    * Redistributions of source code must retain the above copyright notice,
+      this list of conditions and the following disclaimers.
+
+    * Redistributions in binary form must reproduce the above copyright notice,
+      this list of conditions and the following disclaimers in the
+      documentation and/or other materials provided with the distribution.
+
+    * Neither the names of the LLVM Team, University of Illinois at
+      Urbana-Champaign, nor the names of its contributors may be used to
+      endorse or promote products derived from this Software without specific
+      prior written permission.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE
+SOFTWARE.
+
+==============================================================================
+
+Copyright (c) 2009-2014 by the contributors listed in CREDITS.TXT
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

diff --git a/libcxx/MODULE_LICENSE_BSD_LIKE b/libcxx/MODULE_LICENSE_BSD_LIKE
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/libcxx/MODULE_LICENSE_BSD_LIKE


diff --git a/libcxx/Makefile b/libcxx/Makefile
new file mode 100644
index 0000000..ab7b5b6
--- /dev/null
+++ b/libcxx/Makefile

@@ -0,0 +1,56 @@
+##
+# libc++ Makefile
+##
+
+SRCDIRS = .
+DESTDIR = $(DSTROOT)
+
+OBJROOT=.
+SYMROOT=.
+export TRIPLE=-apple-
+
+ifeq (,$(RC_INDIGO))
+	INSTALL_PREFIX=""
+else
+	INSTALL_PREFIX="$(SDKROOT)"
+endif
+INSTALL_DIR=$(DSTROOT)/$(INSTALL_PREFIX)
+
+.PHONY: help installsrc clean installheaders install
+
+help::
+	@echo "Use make install DSTROOT=<destination>"
+
+installsrc:: $(SRCROOT)
+
+	ditto $(SRCDIRS)/include $(SRCROOT)/include
+	ditto $(SRCDIRS)/lib $(SRCROOT)/lib
+	ditto $(SRCDIRS)/src $(SRCROOT)/src
+	ditto $(SRCDIRS)/Makefile $(SRCROOT)/Makefile
+
+clean::
+
+# The installheaders target is used by clang's runtime/libcxx makefile.
+installheaders::
+	mkdir -p $(HEADER_DIR)/c++/v1/ext
+	(cd $(SRCDIRS)/include && \
+	  tar cf - --exclude=".*" --exclude=support \
+	           --exclude=CMakeLists.txt *) | \
+	  (cd $(HEADER_DIR)/c++/v1 && tar xf -)
+	chmod 755 $(HEADER_DIR)/c++/v1
+	chmod 644 $(HEADER_DIR)/c++/v1/*
+	chmod 755 $(HEADER_DIR)/c++/v1/ext
+	chmod 644 $(HEADER_DIR)/c++/v1/ext/*
+	chmod 755 $(HEADER_DIR)/c++/v1/experimental
+	chmod 644 $(HEADER_DIR)/c++/v1/experimental/*
+
+install::
+
+	cd lib && ./buildit
+	ditto lib/libc++.1.dylib $(SYMROOT)/usr/lib/libc++.1.dylib
+	cd lib && dsymutil -o $(SYMROOT)/libc++.1.dylib.dSYM \
+	  $(SYMROOT)/usr/lib/libc++.1.dylib
+	mkdir -p $(INSTALL_DIR)/usr/lib
+	strip -S -o $(INSTALL_DIR)/usr/lib/libc++.1.dylib \
+	  $(SYMROOT)/usr/lib/libc++.1.dylib
+	cd $(INSTALL_DIR)/usr/lib && ln -s libc++.1.dylib libc++.dylib

diff --git a/libcxx/NOTICE b/libcxx/NOTICE
new file mode 100644
index 0000000..41ca5d1
--- /dev/null
+++ b/libcxx/NOTICE

@@ -0,0 +1,76 @@
+==============================================================================
+libc++ License
+==============================================================================
+
+The libc++ library is dual licensed under both the University of Illinois
+"BSD-Like" license and the MIT license.  As a user of this code you may choose
+to use it under either license.  As a contributor, you agree to allow your code
+to be used under both.
+
+Full text of the relevant licenses is included below.
+
+==============================================================================
+
+University of Illinois/NCSA
+Open Source License
+
+Copyright (c) 2009-2014 by the contributors listed in CREDITS.TXT
+
+All rights reserved.
+
+Developed by:
+
+    LLVM Team
+
+    University of Illinois at Urbana-Champaign
+
+    http://llvm.org
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal with
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+    * Redistributions of source code must retain the above copyright notice,
+      this list of conditions and the following disclaimers.
+
+    * Redistributions in binary form must reproduce the above copyright notice,
+      this list of conditions and the following disclaimers in the
+      documentation and/or other materials provided with the distribution.
+
+    * Neither the names of the LLVM Team, University of Illinois at
+      Urbana-Champaign, nor the names of its contributors may be used to
+      endorse or promote products derived from this Software without specific
+      prior written permission.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE
+SOFTWARE.
+
+==============================================================================
+
+Copyright (c) 2009-2014 by the contributors listed in CREDITS.TXT
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

diff --git a/libcxx/README.version b/libcxx/README.version
new file mode 100644
index 0000000..ec7580e
--- /dev/null
+++ b/libcxx/README.version

@@ -0,0 +1,4 @@
+URL: http://llvm.org/git/libcxx.git
+Version: ba865ff66b36f99a1dc5d9e31af3d8943f94e349
+BugComponent: 117395
+Owners: danalbert, srhines, android-llvm

diff --git a/libcxx/TODO.TXT b/libcxx/TODO.TXT
new file mode 100644
index 0000000..513b863
--- /dev/null
+++ b/libcxx/TODO.TXT

@@ -0,0 +1,49 @@
+This is meant to be a general place to list things that should be done "someday"
+
+ABI Related Tasks
+=================
+* Explicitly manage and verify symbols exported from the dylib.
+* Explore using namespaces for managing symbol visibility.
+* Introduce and document ABI versioning/evolution policy.
+
+CXX Runtime Library Tasks
+=========================
+* Cleanup #ifdef hell in sources files that supports the different ABI libraries.
+* Fix that CMake always link to /usr/lib/libc++abi.dylib on OS X.
+* Fix selection of ABI symbol list on OS X.
+* Have CMake generate linker scripts for libc++.so that it properly links the
+  runtime library.
+* Look into mirroring libsupc++'s typeinfo vtable layout when libsupc++/libstdc++
+  is used as the runtime library.
+* Audit libraries that CMake links into libc++. Are they all required?
+* Investigate and document interoperability between libc++ and libstdc++ on
+  linux. Do this for every supported c++ runtime library.
+
+Atomic Related Tasks
+====================
+* Support <atomic> in C++03 (needed for internal use).
+* Audit use of libatomic builtins in <atomic> with GCC.
+* future should use <atomic> for synchronization.
+* call_once should use <atomic> for synchronization.
+* Audit shared_ptr use of <atomic>
+
+Test Suite Tasks
+================
+* Get test suite passing in C++03.
+* Move all libc++ specific tests from test/std into test/libcxx.
+* Improve how LIT handles compiler warnings.
+* Improve the quality and portability of the locale test data.
+
+Misc Tasks
+==========
+* Find all sequences of >2 underscores and eradicate them.
+* run clang-tidy on libc++
+* Document the "conditionally-supported" bits of libc++
+* Look at basic_string's move assignment operator, re LWG 2063 and POCMA
+* libc++ is missing try_emplace
+* Put a static_assert in std::allocator to deny const/volatile types (LWG 2447)
+* Investigate the effect of using __decltype instead of __typeof__ to provide
+  decltype in C++03. What code could be broken by this change?
+* Convert failure tests to use Clang Verify.
+* Document support (or lack of) for C++11 libraries in C++03.
+* Document supported compilers.

diff --git a/libcxx/buildcmds/Android.mk b/libcxx/buildcmds/Android.mk
new file mode 100644
index 0000000..33d01ef
--- /dev/null
+++ b/libcxx/buildcmds/Android.mk

@@ -0,0 +1,42 @@
+#
+# Copyright (C) 2014 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+LOCAL_PATH := $(call my-dir)
+
+# Don't build for unbundled branches
+ifeq (,$(TARGET_BUILD_APPS))
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := libc++_build_commands_$(ANDROID_DEVICE)
+LOCAL_SRC_FILES := dummy.cpp
+LOCAL_CXX_STL := libc++
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/../test/support
+LOCAL_CPPFLAGS := \
+    -std=c++14 \
+    -fsized-deallocation \
+    -fexceptions \
+    -UNDEBUG \
+    -w \
+    -Wno-error=non-virtual-dtor \
+
+# Optimization is causing relocation for nothrow new to be thrown away.
+# http://llvm.org/bugs/show_bug.cgi?id=21421
+LOCAL_CPPFLAGS += -O0
+
+LOCAL_RTTI_FLAG := -frtti
+include $(LOCAL_PATH)/testconfig.mk
+
+endif

diff --git a/libcxx/buildcmds/buildcmdscc b/libcxx/buildcmds/buildcmdscc
new file mode 100755
index 0000000..b169e92
--- /dev/null
+++ b/libcxx/buildcmds/buildcmdscc

@@ -0,0 +1,16 @@
+#!/bin/bash
+CXX=$1
+ARGS=${*:2}
+DIR=external/libcxx/buildcmds
+echo $ANDROID_BUILD_TOP/$CXX > $DIR/cxx_under_test
+
+echo $ARGS | grep -P '\S+\.cpp\b' > /dev/null
+if [ $? -eq 0 ]; then
+  echo $ARGS | perl -ne 's/\S+\.cpp\b/%SOURCE%/; print' \
+             | perl -ne 's/\S+\.o\b/%OUT%/; print' > $DIR/cxx.cmds
+else
+  echo $ARGS | perl -ne 's/out\/\S+\/EXECUTABLES\/\S+\.o\b/%SOURCE%/; print' \
+             | perl -ne 's/-o\s+\S+\b/-o %OUT%/; print' > $DIR/link.cmds
+fi
+
+$CXX $ARGS

diff --git a/libcxx/buildcmds/dummy.cpp b/libcxx/buildcmds/dummy.cpp
new file mode 100644
index 0000000..4cce7f6
--- /dev/null
+++ b/libcxx/buildcmds/dummy.cpp

@@ -0,0 +1,3 @@
+int main() {
+  return 0;
+}

diff --git a/libcxx/cmake/Modules/CodeCoverage.cmake b/libcxx/cmake/Modules/CodeCoverage.cmake
new file mode 100644
index 0000000..addd10a
--- /dev/null
+++ b/libcxx/cmake/Modules/CodeCoverage.cmake

@@ -0,0 +1,36 @@
+find_program(CODE_COVERAGE_LCOV lcov)
+if (NOT CODE_COVERAGE_LCOV)
+  message(FATAL_ERROR "Cannot find lcov...")
+endif()
+
+find_program(CODE_COVERAGE_GENHTML genhtml)
+if (NOT CODE_COVERAGE_GENHTML)
+  message(FATAL_ERROR "Cannot find genhtml...")
+endif()
+
+set(CMAKE_CXX_FLAGS_COVERAGE "-g -O0 --coverage")
+
+function(setup_lcov_test_target_coverage target_name output_dir capture_dirs source_dirs)
+  file(MAKE_DIRECTORY ${output_dir})
+
+  set(CAPTURE_DIRS "")
+  foreach(cdir ${capture_dirs})
+    list(APPEND CAPTURE_DIRS "-d;${cdir}")
+  endforeach()
+
+  set(EXTRACT_DIRS "")
+  foreach(sdir ${source_dirs})
+    list(APPEND EXTRACT_DIRS "'${sdir}/*'")
+  endforeach()
+
+  message(STATUS "Capture Directories: ${CAPTURE_DIRS}")
+  message(STATUS "Extract Directories: ${EXTRACT_DIRS}")
+
+  add_custom_target(generate-lib${target_name}-coverage
+        COMMAND ${CODE_COVERAGE_LCOV} --capture ${CAPTURE_DIRS} -o test_coverage.info
+        COMMAND ${CODE_COVERAGE_LCOV} --extract test_coverage.info ${EXTRACT_DIRS} -o test_coverage.info
+        COMMAND ${CODE_COVERAGE_GENHTML} --demangle-cpp test_coverage.info -o test_coverage
+        COMMAND ${CMAKE_COMMAND} -E remove test_coverage.info
+        WORKING_DIRECTORY ${output_dir}
+        COMMENT "Generating coverage results")
+endfunction()

diff --git a/libcxx/cmake/Modules/HandleLibCXXABI.cmake b/libcxx/cmake/Modules/HandleLibCXXABI.cmake
new file mode 100644
index 0000000..4224882
--- /dev/null
+++ b/libcxx/cmake/Modules/HandleLibCXXABI.cmake

@@ -0,0 +1,118 @@
+
+#===============================================================================
+# Add an ABI library if appropriate
+#===============================================================================
+
+#
+# _setup_abi: Set up the build to use an ABI library
+#
+# Parameters:
+#   abidefines: A list of defines needed to compile libc++ with the ABI library
+#   abilib    : The ABI library to link against.
+#   abifiles  : A list of files (which may be relative paths) to copy into the
+#               libc++ build tree for the build.  These files will also be
+#               installed alongside the libc++ headers.
+#   abidirs   : A list of relative paths to create under an include directory
+#               in the libc++ build directory.
+#
+macro(setup_abi_lib abidefines abilib abifiles abidirs)
+  list(APPEND LIBCXX_COMPILE_FLAGS ${abidefines})
+  set(LIBCXX_CXX_ABI_INCLUDE_PATHS "${LIBCXX_CXX_ABI_INCLUDE_PATHS}"
+    CACHE PATH
+    "Paths to C++ ABI header directories separated by ';'." FORCE
+    )
+
+  set(LIBCXX_CXX_ABI_LIBRARY ${abilib})
+
+  set(LIBCXX_ABILIB_FILES ${abifiles})
+
+  file(MAKE_DIRECTORY "${CMAKE_BINARY_DIR}/include")
+  foreach(_d ${abidirs})
+    file(MAKE_DIRECTORY "${CMAKE_BINARY_DIR}/include/${_d}")
+  endforeach()
+
+  foreach(fpath ${LIBCXX_ABILIB_FILES})
+    set(found FALSE)
+    foreach(incpath ${LIBCXX_CXX_ABI_INCLUDE_PATHS})
+      if (EXISTS "${incpath}/${fpath}")
+        set(found TRUE)
+        get_filename_component(dstdir ${fpath} PATH)
+        get_filename_component(ifile ${fpath} NAME)
+        file(COPY "${incpath}/${fpath}"
+          DESTINATION "${CMAKE_BINARY_DIR}/include/${dstdir}"
+          )
+        install(FILES "${CMAKE_BINARY_DIR}/include/${fpath}"
+          DESTINATION include/c++/v1/${dstdir}
+          PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+          )
+        list(APPEND abilib_headers "${CMAKE_BINARY_DIR}/include/${fpath}")
+      endif()
+    endforeach()
+    if (NOT found)
+      message(WARNING "Failed to find ${fpath}")
+    endif()
+  endforeach()
+
+  add_custom_target(LIBCXX_CXX_ABI_DEPS DEPENDS ${abilib_headers})
+  include_directories("${CMAKE_BINARY_DIR}/include")
+
+endmacro()
+
+# Setup the default options if LIBCXX_CXX_ABI is not specified.
+if (NOT LIBCXX_CXX_ABI)
+  if (NOT DEFINED LIBCXX_BUILT_STANDALONE AND
+      IS_DIRECTORY "${CMAKE_SOURCE_DIR}/projects/libcxxabi")
+    set(LIBCXX_CXX_ABI_LIBNAME "libcxxabi")
+    set(LIBCXX_CXX_ABI_INCLUDE_PATHS "${CMAKE_SOURCE_DIR}/projects/libcxxabi/include")
+    set(LIBCXX_CXX_ABI_INTREE 1)
+  else ()
+    set(LIBCXX_CXX_ABI_LIBNAME "none")
+  endif ()
+else ()
+  set(LIBCXX_CXX_ABI_LIBNAME "${LIBCXX_CXX_ABI}")
+endif ()
+
+# Configure based on the selected ABI library.
+if ("${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libstdc++" OR
+    "${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libsupc++")
+  set(_LIBSUPCXX_INCLUDE_FILES
+    cxxabi.h bits/c++config.h bits/os_defines.h bits/cpu_defines.h
+    bits/cxxabi_tweaks.h bits/cxxabi_forced.h
+    )
+  if ("${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libstdc++")
+    set(_LIBSUPCXX_DEFINES "-DLIBSTDCXX")
+    set(_LIBSUPCXX_LIBNAME stdc++)
+  else()
+    set(_LIBSUPCXX_DEFINES "")
+    set(_LIBSUPCXX_LIBNAME supc++)
+  endif()
+  setup_abi_lib(
+    "-D__GLIBCXX__ ${_LIBSUPCXX_DEFINES}"
+    "${_LIBSUPCXX_LIBNAME}" "${_LIBSUPCXX_INCLUDE_FILES}" "bits"
+    )
+elseif ("${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libcxxabi")
+  if (LIBCXX_CXX_ABI_INTREE)
+    # Link against just-built "cxxabi" target.
+    if (LIBCXX_ENABLE_STATIC_ABI_LIBRARY)
+        set(CXXABI_LIBNAME cxxabi_static)
+    else()
+        set(CXXABI_LIBNAME cxxabi_shared)
+    endif()
+    set(LIBCXX_LIBCPPABI_VERSION "2" PARENT_SCOPE)
+  else()
+    # Assume c++abi is installed in the system, rely on -lc++abi link flag.
+    set(CXXABI_LIBNAME "c++abi")
+  endif()
+  setup_abi_lib("-DLIBCXX_BUILDING_LIBCXXABI"
+    ${CXXABI_LIBNAME} "cxxabi.h;__cxxabi_config.h" ""
+    )
+elseif ("${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "libcxxrt")
+  setup_abi_lib("-DLIBCXXRT"
+    "cxxrt" "cxxabi.h;unwind.h;unwind-arm.h;unwind-itanium.h" ""
+    )
+elseif (NOT "${LIBCXX_CXX_ABI_LIBNAME}" STREQUAL "none")
+  message(FATAL_ERROR
+    "Currently libstdc++, libsupc++, libcxxabi, libcxxrt and none are "
+    "supported for c++ abi."
+    )
+endif ()

diff --git a/libcxx/cmake/Modules/HandleLibcxxFlags.cmake b/libcxx/cmake/Modules/HandleLibcxxFlags.cmake
new file mode 100644
index 0000000..223b7b7
--- /dev/null
+++ b/libcxx/cmake/Modules/HandleLibcxxFlags.cmake

@@ -0,0 +1,147 @@
+# HandleLibcxxFlags - A set of macros used to setup the flags used to compile
+# and link libc++. These macros add flags to the following CMake variables.
+# - LIBCXX_COMPILE_FLAGS: flags used to compile libc++
+# - LIBCXX_LINK_FLAGS: flags used to link libc++
+# - LIBCXX_LIBRARIES: libraries to link libc++ to.
+
+include(CheckCXXCompilerFlag)
+
+unset(add_flag_if_supported)
+
+# Mangle the name of a compiler flag into a valid CMake identifier.
+# Ex: --std=c++11 -> STD_EQ_CXX11
+macro(mangle_name str output)
+  string(STRIP "${str}" strippedStr)
+  string(REGEX REPLACE "^/" "" strippedStr "${strippedStr}")
+  string(REGEX REPLACE "^-+" "" strippedStr "${strippedStr}")
+  string(REGEX REPLACE "-+$" "" strippedStr "${strippedStr}")
+  string(REPLACE "-" "_" strippedStr "${strippedStr}")
+  string(REPLACE "=" "_EQ_" strippedStr "${strippedStr}")
+  string(REPLACE "+" "X" strippedStr "${strippedStr}")
+  string(TOUPPER "${strippedStr}" ${output})
+endmacro()
+
+# Remove a list of flags from all CMake variables that affect compile flags.
+# This can be used to remove unwanted flags specified on the command line
+# or added in other parts of LLVM's cmake configuration.
+macro(remove_flags)
+  foreach(var ${ARGN})
+    string(REPLACE "${var}" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
+    string(REPLACE "${var}" "" CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
+    string(REPLACE "${var}" "" CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS}")
+    string(REPLACE "${var}" "" CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS}")
+    string(REPLACE "${var}" "" CMAKE_SHARED_MODULE_FLAGS "${CMAKE_SHARED_MODULE_FLAGS}")
+    remove_definitions(${var})
+  endforeach()
+endmacro(remove_flags)
+
+# Add a macro definition if condition is true.
+macro(define_if condition def)
+  if (${condition})
+    add_definitions(${def})
+  endif()
+endmacro()
+
+# Add a macro definition if condition is not true.
+macro(define_if_not condition def)
+  if (NOT ${condition})
+    add_definitions(${def})
+  endif()
+endmacro()
+
+# Add a specified list of flags to both 'LIBCXX_COMPILE_FLAGS' and
+# 'LIBCXX_LINK_FLAGS'.
+macro(add_flags)
+  foreach(value ${ARGN})
+    list(APPEND LIBCXX_COMPILE_FLAGS ${value})
+    list(APPEND LIBCXX_LINK_FLAGS ${value})
+  endforeach()
+endmacro()
+
+# If the specified 'condition' is true then add a list of flags to both
+# 'LIBCXX_COMPILE_FLAGS' and 'LIBCXX_LINK_FLAGS'.
+macro(add_flags_if condition)
+  if (${condition})
+    add_flags(${ARGN})
+  endif()
+endmacro()
+
+# Add each flag in the list to LIBCXX_COMPILE_FLAGS and LIBCXX_LINK_FLAGS
+# if that flag is supported by the current compiler.
+macro(add_flags_if_supported)
+  foreach(flag ${ARGN})
+      mangle_name("${flag}" flagname)
+      check_cxx_compiler_flag("${flag}" "LIBCXX_SUPPORTS_${flagname}_FLAG")
+      add_flags_if(LIBCXX_SUPPORTS_${flagname}_FLAG ${flag})
+  endforeach()
+endmacro()
+
+# Add a list of flags to 'LIBCXX_COMPILE_FLAGS'.
+macro(add_compile_flags)
+  foreach(f ${ARGN})
+    list(APPEND LIBCXX_COMPILE_FLAGS ${f})
+  endforeach()
+endmacro()
+
+# If 'condition' is true then add the specified list of flags to
+# 'LIBCXX_COMPILE_FLAGS'
+macro(add_compile_flags_if condition)
+  if (${condition})
+    add_compile_flags(${ARGN})
+  endif()
+endmacro()
+
+# For each specified flag, add that flag to 'LIBCXX_COMPILE_FLAGS' if the
+# flag is supported by the C++ compiler.
+macro(add_compile_flags_if_supported)
+  foreach(flag ${ARGN})
+      mangle_name("${flag}" flagname)
+      check_cxx_compiler_flag("${flag}" "LIBCXX_SUPPORTS_${flagname}_FLAG")
+      add_compile_flags_if(LIBCXX_SUPPORTS_${flagname}_FLAG ${flag})
+  endforeach()
+endmacro()
+
+# Add a list of flags to 'LIBCXX_LINK_FLAGS'.
+macro(add_link_flags)
+  foreach(f ${ARGN})
+    list(APPEND LIBCXX_LINK_FLAGS ${f})
+  endforeach()
+endmacro()
+
+# If 'condition' is true then add the specified list of flags to
+# 'LIBCXX_LINK_FLAGS'
+macro(add_link_flags_if condition)
+  if (${condition})
+    add_link_flags(${ARGN})
+  endif()
+endmacro()
+
+# For each specified flag, add that flag to 'LIBCXX_LINK_FLAGS' if the
+# flag is supported by the C++ compiler.
+macro(add_link_flags_if_supported)
+  foreach(flag ${ARGN})
+    mangle_name("${flag}" flagname)
+    check_cxx_compiler_flag("${flag}" "LIBCXX_SUPPORTS_${flagname}_FLAG")
+    add_link_flags_if(LIBCXX_SUPPORTS_${flagname}_FLAG ${flag})
+  endforeach()
+endmacro()
+
+# Add a list of libraries or link flags to 'LIBCXX_LIBRARIES'.
+macro(add_library_flags)
+  foreach(lib ${ARGN})
+    list(APPEND LIBCXX_LIBRARIES ${lib})
+  endforeach()
+endmacro()
+
+# if 'condition' is true then add the specified list of libraries and flags
+# to 'LIBCXX_LIBRARIES'.
+macro(add_library_flags_if condition)
+  if(${condition})
+    add_library_flags(${ARGN})
+  endif()
+endmacro()
+
+# Turn a comma separated CMake list into a space separated string.
+macro(split_list listname)
+  string(REPLACE ";" " " ${listname} "${${listname}}")
+endmacro()

diff --git a/libcxx/cmake/Modules/HandleOutOfTreeLLVM.cmake b/libcxx/cmake/Modules/HandleOutOfTreeLLVM.cmake
new file mode 100644
index 0000000..bf629a9
--- /dev/null
+++ b/libcxx/cmake/Modules/HandleOutOfTreeLLVM.cmake

@@ -0,0 +1,96 @@
+macro(find_llvm_parts)
+# Rely on llvm-config.
+  set(CONFIG_OUTPUT)
+  find_program(LLVM_CONFIG "llvm-config")
+  if(DEFINED LLVM_PATH)
+    set(LLVM_INCLUDE_DIR ${LLVM_INCLUDE_DIR} CACHE PATH "Path to llvm/include")
+    set(LLVM_PATH ${LLVM_PATH} CACHE PATH "Path to LLVM source tree")
+    set(LLVM_MAIN_SRC_DIR ${LLVM_PATH})
+    set(LLVM_CMAKE_PATH "${LLVM_PATH}/cmake/modules")
+  elseif(LLVM_CONFIG)
+    message(STATUS "Found LLVM_CONFIG as ${LLVM_CONFIG}")
+    set(CONFIG_COMMAND ${LLVM_CONFIG}
+      "--includedir"
+      "--prefix"
+      "--src-root")
+    execute_process(
+      COMMAND ${CONFIG_COMMAND}
+      RESULT_VARIABLE HAD_ERROR
+      OUTPUT_VARIABLE CONFIG_OUTPUT
+    )
+    if(NOT HAD_ERROR)
+      string(REGEX REPLACE
+        "[ \t]*[\r\n]+[ \t]*" ";"
+        CONFIG_OUTPUT ${CONFIG_OUTPUT})
+    else()
+      string(REPLACE ";" " " CONFIG_COMMAND_STR "${CONFIG_COMMAND}")
+      message(STATUS "${CONFIG_COMMAND_STR}")
+      message(FATAL_ERROR "llvm-config failed with status ${HAD_ERROR}")
+    endif()
+
+    list(GET CONFIG_OUTPUT 0 INCLUDE_DIR)
+    list(GET CONFIG_OUTPUT 1 LLVM_OBJ_ROOT)
+    list(GET CONFIG_OUTPUT 2 MAIN_SRC_DIR)
+
+    set(LLVM_INCLUDE_DIR ${INCLUDE_DIR} CACHE PATH "Path to llvm/include")
+    set(LLVM_BINARY_DIR ${LLVM_OBJ_ROOT} CACHE PATH "Path to LLVM build tree")
+    set(LLVM_MAIN_SRC_DIR ${MAIN_SRC_DIR} CACHE PATH "Path to LLVM source tree")
+    set(LLVM_CMAKE_PATH "${LLVM_BINARY_DIR}/share/llvm/cmake")
+  else()
+    set(LLVM_FOUND OFF)
+    return()
+  endif()
+
+  if (NOT EXISTS ${LLVM_MAIN_SRC_DIR})
+    message(FATAL_ERROR "Not found: ${LLVM_MAIN_SRC_DIR}")
+  endif()
+
+  if(NOT EXISTS ${LLVM_CMAKE_PATH})
+    message(FATAL_ERROR "Not found: ${LLVM_CMAKE_PATH}")
+  endif()
+
+  list(APPEND CMAKE_MODULE_PATH "${LLVM_CMAKE_PATH}")
+  list(APPEND CMAKE_MODULE_PATH "${LLVM_MAIN_SRC_DIR}/cmake/modules")
+
+  set(LLVM_FOUND ON)
+endmacro(find_llvm_parts)
+
+
+if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
+  set(LIBCXX_BUILT_STANDALONE 1)
+  message(STATUS "Configuring for standalone build.")
+
+  find_llvm_parts()
+
+  # LLVM Options --------------------------------------------------------------
+  include(FindPythonInterp)
+  if( NOT PYTHONINTERP_FOUND )
+    message(WARNING "Failed to find python interpreter. "
+                    "The libc++ test suite will be disabled.")
+    set(LLVM_INCLUDE_TESTS OFF)
+  endif()
+
+  if (NOT DEFINED LLVM_INCLUDE_TESTS)
+    set(LLVM_INCLUDE_TESTS ${LLVM_FOUND})
+  endif()
+
+  # Required LIT Configuration ------------------------------------------------
+  # Define the default arguments to use with 'lit', and an option for the user
+  # to override.
+  set(LIT_ARGS_DEFAULT "-sv --show-xfail --show-unsupported")
+  if (MSVC OR XCODE)
+    set(LIT_ARGS_DEFAULT "${LIT_ARGS_DEFAULT} --no-progress-bar")
+  endif()
+  set(LLVM_LIT_ARGS "${LIT_ARGS_DEFAULT}" CACHE STRING "Default options for lit")
+
+  # Make sure we can use the console pool for recent cmake and ninja > 1.5
+  # Needed for add_lit_testsuite
+  if(CMAKE_VERSION VERSION_LESS 3.1.20141117)
+    set(cmake_3_2_USES_TERMINAL)
+  else()
+    set(cmake_3_2_USES_TERMINAL USES_TERMINAL)
+  endif()
+
+  # Add LLVM Functions --------------------------------------------------------
+  include(AddLLVM OPTIONAL)
+endif()

diff --git a/libcxx/cmake/Modules/MacroEnsureOutOfSourceBuild.cmake b/libcxx/cmake/Modules/MacroEnsureOutOfSourceBuild.cmake
new file mode 100644
index 0000000..a066936
--- /dev/null
+++ b/libcxx/cmake/Modules/MacroEnsureOutOfSourceBuild.cmake

@@ -0,0 +1,18 @@
+# MACRO_ENSURE_OUT_OF_SOURCE_BUILD(<errorMessage>)
+
+macro( MACRO_ENSURE_OUT_OF_SOURCE_BUILD _errorMessage )
+
+string( COMPARE EQUAL "${CMAKE_SOURCE_DIR}" "${CMAKE_BINARY_DIR}" _insource )
+if( _insource )
+ message( SEND_ERROR "${_errorMessage}" )
+ message( FATAL_ERROR
+ "In-source builds are not allowed.
+ CMake would overwrite the makefiles distributed with Compiler-RT.
+ Please create a directory and run cmake from there, passing the path
+ to this source directory as the last argument.
+ This process created the file `CMakeCache.txt' and the directory `CMakeFiles'.
+ Please delete them."
+ )
+endif( _insource )
+
+endmacro( MACRO_ENSURE_OUT_OF_SOURCE_BUILD )

diff --git a/libcxx/cmake/config-ix.cmake b/libcxx/cmake/config-ix.cmake
new file mode 100644
index 0000000..ace7aca
--- /dev/null
+++ b/libcxx/cmake/config-ix.cmake

@@ -0,0 +1,20 @@
+include(CheckLibraryExists)
+include(CheckCXXCompilerFlag)
+
+# Check compiler flags
+
+check_cxx_compiler_flag(/WX                     LIBCXX_HAS_WX_FLAG)
+check_cxx_compiler_flag(/WX-                    LIBCXX_HAS_NO_WX_FLAG)
+check_cxx_compiler_flag(/EHsc                   LIBCXX_HAS_EHSC_FLAG)
+check_cxx_compiler_flag(/EHs-                   LIBCXX_HAS_NO_EHS_FLAG)
+check_cxx_compiler_flag(/EHa-                   LIBCXX_HAS_NO_EHA_FLAG)
+check_cxx_compiler_flag(/GR-                    LIBCXX_HAS_NO_GR_FLAG)
+
+
+# Check libraries
+check_library_exists(pthread pthread_create "" LIBCXX_HAS_PTHREAD_LIB)
+check_library_exists(c printf "" LIBCXX_HAS_C_LIB)
+check_library_exists(m ccos "" LIBCXX_HAS_M_LIB)
+check_library_exists(rt clock_gettime "" LIBCXX_HAS_RT_LIB)
+check_library_exists(gcc_s __gcc_personality_v0 "" LIBCXX_HAS_GCC_S_LIB)
+

diff --git a/libcxx/include/CMakeLists.txt b/libcxx/include/CMakeLists.txt
new file mode 100644
index 0000000..95206bf
--- /dev/null
+++ b/libcxx/include/CMakeLists.txt

@@ -0,0 +1,24 @@
+if (NOT LIBCXX_INSTALL_SUPPORT_HEADERS)
+  set(LIBCXX_SUPPORT_HEADER_PATTERN PATTERN "support" EXCLUDE)
+endif()
+set(LIBCXX_HEADER_PATTERN
+  PATTERN "*"
+  PATTERN "CMakeLists.txt" EXCLUDE
+  PATTERN ".svn" EXCLUDE
+  ${LIBCXX_SUPPORT_HEADER_PATTERN}
+  )
+
+file(COPY .
+  DESTINATION "${CMAKE_BINARY_DIR}/include/c++/v1"
+  FILES_MATCHING
+  ${LIBCXX_HEADER_PATTERN}
+  )
+
+if (LIBCXX_INSTALL_HEADERS)
+  install(DIRECTORY .
+    DESTINATION include/c++/v1
+    FILES_MATCHING
+    ${LIBCXX_HEADER_PATTERN}
+    PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+  )
+endif()

diff --git a/libcxx/include/__bit_reference b/libcxx/include/__bit_reference
new file mode 100644
index 0000000..5659ed0
--- /dev/null
+++ b/libcxx/include/__bit_reference

@@ -0,0 +1,1286 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___BIT_REFERENCE
+#define _LIBCPP___BIT_REFERENCE
+
+#include <__config>
+#include <algorithm>
+
+#include <__undef_min_max>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Cp, bool _IsConst, typename _Cp::__storage_type = 0> class __bit_iterator;
+template <class _Cp> class __bit_const_reference;
+
+template <class _Tp>
+struct __has_storage_type
+{
+    static const bool value = false;
+};
+
+template <class _Cp, bool = __has_storage_type<_Cp>::value>
+class __bit_reference
+{
+    typedef typename _Cp::__storage_type    __storage_type;
+    typedef typename _Cp::__storage_pointer __storage_pointer;
+
+    __storage_pointer __seg_;
+    __storage_type    __mask_;
+
+#if defined(__clang__) || defined(__IBMCPP__) || defined(_LIBCPP_MSVC)
+    friend typename _Cp::__self;
+#else
+    friend class _Cp::__self;
+#endif
+    friend class __bit_const_reference<_Cp>;
+    friend class __bit_iterator<_Cp, false>;
+public:
+    _LIBCPP_INLINE_VISIBILITY operator bool() const _NOEXCEPT
+        {return static_cast<bool>(*__seg_ & __mask_);}
+    _LIBCPP_INLINE_VISIBILITY bool operator ~() const _NOEXCEPT
+        {return !static_cast<bool>(*this);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __bit_reference& operator=(bool __x) _NOEXCEPT
+    {
+        if (__x)
+            *__seg_ |= __mask_;
+        else
+            *__seg_ &= ~__mask_;
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __bit_reference& operator=(const __bit_reference& __x) _NOEXCEPT
+        {return operator=(static_cast<bool>(__x));}
+
+    _LIBCPP_INLINE_VISIBILITY void flip() _NOEXCEPT {*__seg_ ^= __mask_;}
+    _LIBCPP_INLINE_VISIBILITY __bit_iterator<_Cp, false> operator&() const _NOEXCEPT
+        {return __bit_iterator<_Cp, false>(__seg_, static_cast<unsigned>(__ctz(__mask_)));}
+private:
+    _LIBCPP_INLINE_VISIBILITY
+    __bit_reference(__storage_pointer __s, __storage_type __m) _NOEXCEPT
+        : __seg_(__s), __mask_(__m) {}
+};
+
+template <class _Cp>
+class __bit_reference<_Cp, false>
+{
+};
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(__bit_reference<_Cp> __x, __bit_reference<_Cp> __y) _NOEXCEPT
+{
+    bool __t = __x;
+    __x = __y;
+    __y = __t;
+}
+
+template <class _Cp, class _Dp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(__bit_reference<_Cp> __x, __bit_reference<_Dp> __y) _NOEXCEPT
+{
+    bool __t = __x;
+    __x = __y;
+    __y = __t;
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(__bit_reference<_Cp> __x, bool& __y) _NOEXCEPT
+{
+    bool __t = __x;
+    __x = __y;
+    __y = __t;
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(bool& __x, __bit_reference<_Cp> __y) _NOEXCEPT
+{
+    bool __t = __x;
+    __x = __y;
+    __y = __t;
+}
+
+template <class _Cp>
+class __bit_const_reference
+{
+    typedef typename _Cp::__storage_type          __storage_type;
+    typedef typename _Cp::__const_storage_pointer __storage_pointer;
+
+    __storage_pointer        __seg_;
+    __storage_type __mask_;
+
+#if defined(__clang__) || defined(__IBMCPP__) || defined(_LIBCPP_MSVC)
+    friend typename _Cp::__self;
+#else
+    friend class _Cp::__self;
+#endif
+    friend class __bit_iterator<_Cp, true>;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    __bit_const_reference(const __bit_reference<_Cp>& __x) _NOEXCEPT
+        : __seg_(__x.__seg_), __mask_(__x.__mask_) {}
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR operator bool() const _NOEXCEPT
+        {return static_cast<bool>(*__seg_ & __mask_);}
+
+    _LIBCPP_INLINE_VISIBILITY __bit_iterator<_Cp, true> operator&() const _NOEXCEPT
+        {return __bit_iterator<_Cp, true>(__seg_, static_cast<unsigned>(__ctz(__mask_)));}
+private:
+    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR
+    __bit_const_reference(__storage_pointer __s, __storage_type __m) _NOEXCEPT
+        : __seg_(__s), __mask_(__m) {}
+
+    __bit_const_reference& operator=(const __bit_const_reference& __x);
+};
+
+// find
+
+template <class _Cp, bool _IsConst>
+__bit_iterator<_Cp, _IsConst>
+__find_bool_true(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type __n)
+{
+    typedef __bit_iterator<_Cp, _IsConst> _It;
+    typedef typename _It::__storage_type __storage_type;
+    static const unsigned __bits_per_word = _It::__bits_per_word;
+    // do first partial word
+    if (__first.__ctz_ != 0)
+    {
+        __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
+        __storage_type __dn = _VSTD::min(__clz_f, __n);
+        __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
+        __storage_type __b = *__first.__seg_ & __m;
+        if (__b)
+            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(__b)));
+        if (__n == __dn)
+            return __first + __n;
+        __n -= __dn;
+        ++__first.__seg_;
+    }
+    // do middle whole words
+    for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word)
+        if (*__first.__seg_)
+            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(*__first.__seg_)));
+    // do last partial word
+    if (__n > 0)
+    {
+        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
+        __storage_type __b = *__first.__seg_ & __m;
+        if (__b)
+            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(__b)));
+    }
+    return _It(__first.__seg_, static_cast<unsigned>(__n));
+}
+
+template <class _Cp, bool _IsConst>
+__bit_iterator<_Cp, _IsConst>
+__find_bool_false(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type __n)
+{
+    typedef __bit_iterator<_Cp, _IsConst> _It;
+    typedef typename _It::__storage_type __storage_type;
+    static const unsigned __bits_per_word = _It::__bits_per_word;
+    // do first partial word
+    if (__first.__ctz_ != 0)
+    {
+        __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
+        __storage_type __dn = _VSTD::min(__clz_f, __n);
+        __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
+        __storage_type __b = ~*__first.__seg_ & __m;
+        if (__b)
+            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(__b)));
+        if (__n == __dn)
+            return __first + __n;
+        __n -= __dn;
+        ++__first.__seg_;
+    }
+    // do middle whole words
+    for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word)
+    {
+        __storage_type __b = ~*__first.__seg_;
+        if (__b)
+            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(__b)));
+    }
+    // do last partial word
+    if (__n > 0)
+    {
+        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
+        __storage_type __b = ~*__first.__seg_ & __m;
+        if (__b)
+            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(__b)));
+    }
+    return _It(__first.__seg_, static_cast<unsigned>(__n));
+}
+
+template <class _Cp, bool _IsConst, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+__bit_iterator<_Cp, _IsConst>
+find(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, const _Tp& __value_)
+{
+    if (static_cast<bool>(__value_))
+        return __find_bool_true(__first, static_cast<typename _Cp::size_type>(__last - __first));
+    return __find_bool_false(__first, static_cast<typename _Cp::size_type>(__last - __first));
+}
+
+// count
+
+template <class _Cp, bool _IsConst>
+typename __bit_iterator<_Cp, _IsConst>::difference_type
+__count_bool_true(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type __n)
+{
+    typedef __bit_iterator<_Cp, _IsConst> _It;
+    typedef typename _It::__storage_type __storage_type;
+    typedef typename _It::difference_type difference_type;
+    static const unsigned __bits_per_word = _It::__bits_per_word;
+    difference_type __r = 0;
+    // do first partial word
+    if (__first.__ctz_ != 0)
+    {
+        __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
+        __storage_type __dn = _VSTD::min(__clz_f, __n);
+        __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
+        __r = _VSTD::__pop_count(*__first.__seg_ & __m);
+        __n -= __dn;
+        ++__first.__seg_;
+    }
+    // do middle whole words
+    for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word)
+        __r += _VSTD::__pop_count(*__first.__seg_);
+    // do last partial word
+    if (__n > 0)
+    {
+        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
+        __r += _VSTD::__pop_count(*__first.__seg_ & __m);
+    }
+    return __r;
+}
+
+template <class _Cp, bool _IsConst>
+typename __bit_iterator<_Cp, _IsConst>::difference_type
+__count_bool_false(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type __n)
+{
+    typedef __bit_iterator<_Cp, _IsConst> _It;
+    typedef typename _It::__storage_type __storage_type;
+    typedef typename _It::difference_type difference_type;
+    static const unsigned __bits_per_word = _It::__bits_per_word;
+    difference_type __r = 0;
+    // do first partial word
+    if (__first.__ctz_ != 0)
+    {
+        __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
+        __storage_type __dn = _VSTD::min(__clz_f, __n);
+        __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
+        __r = _VSTD::__pop_count(~*__first.__seg_ & __m);
+        __n -= __dn;
+        ++__first.__seg_;
+    }
+    // do middle whole words
+    for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word)
+        __r += _VSTD::__pop_count(~*__first.__seg_);
+    // do last partial word
+    if (__n > 0)
+    {
+        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
+        __r += _VSTD::__pop_count(~*__first.__seg_ & __m);
+    }
+    return __r;
+}
+
+template <class _Cp, bool _IsConst, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __bit_iterator<_Cp, _IsConst>::difference_type
+count(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, const _Tp& __value_)
+{
+    if (static_cast<bool>(__value_))
+        return __count_bool_true(__first, static_cast<typename _Cp::size_type>(__last - __first));
+    return __count_bool_false(__first, static_cast<typename _Cp::size_type>(__last - __first));
+}
+
+// fill_n
+
+template <class _Cp>
+void
+__fill_n_false(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n)
+{
+    typedef __bit_iterator<_Cp, false> _It;
+    typedef typename _It::__storage_type __storage_type;
+    static const unsigned __bits_per_word = _It::__bits_per_word;
+    // do first partial word
+    if (__first.__ctz_ != 0)
+    {
+        __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
+        __storage_type __dn = _VSTD::min(__clz_f, __n);
+        __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
+        *__first.__seg_ &= ~__m;
+        __n -= __dn;
+        ++__first.__seg_;
+    }
+    // do middle whole words
+    __storage_type __nw = __n / __bits_per_word;
+    _VSTD::memset(_VSTD::__to_raw_pointer(__first.__seg_), 0, __nw * sizeof(__storage_type));
+    __n -= __nw * __bits_per_word;
+    // do last partial word
+    if (__n > 0)
+    {
+        __first.__seg_ += __nw;
+        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
+        *__first.__seg_ &= ~__m;
+    }
+}
+
+template <class _Cp>
+void
+__fill_n_true(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n)
+{
+    typedef __bit_iterator<_Cp, false> _It;
+    typedef typename _It::__storage_type __storage_type;
+    static const unsigned __bits_per_word = _It::__bits_per_word;
+    // do first partial word
+    if (__first.__ctz_ != 0)
+    {
+        __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
+        __storage_type __dn = _VSTD::min(__clz_f, __n);
+        __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
+        *__first.__seg_ |= __m;
+        __n -= __dn;
+        ++__first.__seg_;
+    }
+    // do middle whole words
+    __storage_type __nw = __n / __bits_per_word;
+    _VSTD::memset(_VSTD::__to_raw_pointer(__first.__seg_), -1, __nw * sizeof(__storage_type));
+    __n -= __nw * __bits_per_word;
+    // do last partial word
+    if (__n > 0)
+    {
+        __first.__seg_ += __nw;
+        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
+        *__first.__seg_ |= __m;
+    }
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+fill_n(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n, bool __value_)
+{
+    if (__n > 0)
+    {
+        if (__value_)
+            __fill_n_true(__first, __n);
+        else
+            __fill_n_false(__first, __n);
+    }
+}
+
+// fill
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+fill(__bit_iterator<_Cp, false> __first, __bit_iterator<_Cp, false> __last, bool __value_)
+{
+    _VSTD::fill_n(__first, static_cast<typename _Cp::size_type>(__last - __first), __value_);
+}
+
+// copy
+
+template <class _Cp, bool _IsConst>
+__bit_iterator<_Cp, false>
+__copy_aligned(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last,
+                                                     __bit_iterator<_Cp, false> __result)
+{
+    typedef __bit_iterator<_Cp, _IsConst> _In;
+    typedef  typename _In::difference_type difference_type;
+    typedef typename _In::__storage_type __storage_type;
+    static const unsigned __bits_per_word = _In::__bits_per_word;
+    difference_type __n = __last - __first;
+    if (__n > 0)
+    {
+        // do first word
+        if (__first.__ctz_ != 0)
+        {
+            unsigned __clz = __bits_per_word - __first.__ctz_;
+            difference_type __dn = _VSTD::min(static_cast<difference_type>(__clz), __n);
+            __n -= __dn;
+            __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz - __dn));
+            __storage_type __b = *__first.__seg_ & __m;
+            *__result.__seg_ &= ~__m;
+            *__result.__seg_ |= __b;
+            __result.__seg_ += (__dn + __result.__ctz_) / __bits_per_word;
+            __result.__ctz_ = static_cast<unsigned>((__dn + __result.__ctz_)  % __bits_per_word);
+            ++__first.__seg_;
+            // __first.__ctz_ = 0;
+        }
+        // __first.__ctz_ == 0;
+        // do middle words
+        __storage_type __nw = __n / __bits_per_word;
+        _VSTD::memmove(_VSTD::__to_raw_pointer(__result.__seg_),
+                       _VSTD::__to_raw_pointer(__first.__seg_),
+                       __nw * sizeof(__storage_type));
+        __n -= __nw * __bits_per_word;
+        __result.__seg_ += __nw;
+        // do last word
+        if (__n > 0)
+        {
+            __first.__seg_ += __nw;
+            __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
+            __storage_type __b = *__first.__seg_ & __m;
+            *__result.__seg_ &= ~__m;
+            *__result.__seg_ |= __b;
+            __result.__ctz_ = static_cast<unsigned>(__n);
+        }
+    }
+    return __result;
+}
+
+template <class _Cp, bool _IsConst>
+__bit_iterator<_Cp, false>
+__copy_unaligned(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last,
+                                                       __bit_iterator<_Cp, false> __result)
+{
+    typedef __bit_iterator<_Cp, _IsConst> _In;
+    typedef  typename _In::difference_type difference_type;
+    typedef typename _In::__storage_type __storage_type;
+    static const unsigned __bits_per_word = _In::__bits_per_word;
+    difference_type __n = __last - __first;
+    if (__n > 0)
+    {
+        // do first word
+        if (__first.__ctz_ != 0)
+        {
+            unsigned __clz_f = __bits_per_word - __first.__ctz_;
+            difference_type __dn = _VSTD::min(static_cast<difference_type>(__clz_f), __n);
+            __n -= __dn;
+            __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
+            __storage_type __b = *__first.__seg_ & __m;
+            unsigned __clz_r = __bits_per_word - __result.__ctz_;
+            __storage_type __ddn = _VSTD::min<__storage_type>(__dn, __clz_r);
+            __m = (~__storage_type(0) << __result.__ctz_) & (~__storage_type(0) >> (__clz_r - __ddn));
+            *__result.__seg_ &= ~__m;
+            if (__result.__ctz_ > __first.__ctz_)
+                *__result.__seg_ |= __b << (__result.__ctz_ - __first.__ctz_);
+            else
+                *__result.__seg_ |= __b >> (__first.__ctz_ - __result.__ctz_);
+            __result.__seg_ += (__ddn + __result.__ctz_) / __bits_per_word;
+            __result.__ctz_ = static_cast<unsigned>((__ddn + __result.__ctz_)  % __bits_per_word);
+            __dn -= __ddn;
+            if (__dn > 0)
+            {
+                __m = ~__storage_type(0) >> (__bits_per_word - __dn);
+                *__result.__seg_ &= ~__m;
+                *__result.__seg_ |= __b >> (__first.__ctz_ + __ddn);
+                __result.__ctz_ = static_cast<unsigned>(__dn);
+            }
+            ++__first.__seg_;
+            // __first.__ctz_ = 0;
+        }
+        // __first.__ctz_ == 0;
+        // do middle words
+        unsigned __clz_r = __bits_per_word - __result.__ctz_;
+        __storage_type __m = ~__storage_type(0) << __result.__ctz_;
+        for (; __n >= __bits_per_word; __n -= __bits_per_word, ++__first.__seg_)
+        {
+            __storage_type __b = *__first.__seg_;
+            *__result.__seg_ &= ~__m;
+            *__result.__seg_ |= __b << __result.__ctz_;
+            ++__result.__seg_;
+            *__result.__seg_ &= __m;
+            *__result.__seg_ |= __b >> __clz_r;
+        }
+        // do last word
+        if (__n > 0)
+        {
+            __m = ~__storage_type(0) >> (__bits_per_word - __n);
+            __storage_type __b = *__first.__seg_ & __m;
+            __storage_type __dn = _VSTD::min(__n, static_cast<difference_type>(__clz_r));
+            __m = (~__storage_type(0) << __result.__ctz_) & (~__storage_type(0) >> (__clz_r - __dn));
+            *__result.__seg_ &= ~__m;
+            *__result.__seg_ |= __b << __result.__ctz_;
+            __result.__seg_ += (__dn + __result.__ctz_) / __bits_per_word;
+            __result.__ctz_ = static_cast<unsigned>((__dn + __result.__ctz_)  % __bits_per_word);
+            __n -= __dn;
+            if (__n > 0)
+            {
+                __m = ~__storage_type(0) >> (__bits_per_word - __n);
+                *__result.__seg_ &= ~__m;
+                *__result.__seg_ |= __b >> __dn;
+                __result.__ctz_ = static_cast<unsigned>(__n);
+            }
+        }
+    }
+    return __result;
+}
+
+template <class _Cp, bool _IsConst>
+inline _LIBCPP_INLINE_VISIBILITY
+__bit_iterator<_Cp, false>
+copy(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, __bit_iterator<_Cp, false> __result)
+{
+    if (__first.__ctz_ == __result.__ctz_)
+        return __copy_aligned(__first, __last, __result);
+    return __copy_unaligned(__first, __last, __result);
+}
+
+// copy_backward
+
+template <class _Cp, bool _IsConst>
+__bit_iterator<_Cp, false>
+__copy_backward_aligned(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last,
+                                                     __bit_iterator<_Cp, false> __result)
+{
+    typedef __bit_iterator<_Cp, _IsConst> _In;
+    typedef  typename _In::difference_type difference_type;
+    typedef typename _In::__storage_type __storage_type;
+    static const unsigned __bits_per_word = _In::__bits_per_word;
+    difference_type __n = __last - __first;
+    if (__n > 0)
+    {
+        // do first word
+        if (__last.__ctz_ != 0)
+        {
+            difference_type __dn = _VSTD::min(static_cast<difference_type>(__last.__ctz_), __n);
+            __n -= __dn;
+            unsigned __clz = __bits_per_word - __last.__ctz_;
+            __storage_type __m = (~__storage_type(0) << (__last.__ctz_ - __dn)) & (~__storage_type(0) >> __clz);
+            __storage_type __b = *__last.__seg_ & __m;
+            *__result.__seg_ &= ~__m;
+            *__result.__seg_ |= __b;
+            __result.__ctz_ = static_cast<unsigned>(((-__dn & (__bits_per_word - 1)) +
+                                                       __result.__ctz_)  % __bits_per_word);
+            // __last.__ctz_ = 0
+         }
+        // __last.__ctz_ == 0 || __n == 0
+        // __result.__ctz_ == 0 || __n == 0
+        // do middle words
+        __storage_type __nw = __n / __bits_per_word;
+        __result.__seg_ -= __nw;
+        __last.__seg_ -= __nw;
+        _VSTD::memmove(_VSTD::__to_raw_pointer(__result.__seg_),
+                       _VSTD::__to_raw_pointer(__last.__seg_),
+                       __nw * sizeof(__storage_type));
+        __n -= __nw * __bits_per_word;
+        // do last word
+        if (__n > 0)
+        {
+            __storage_type __m = ~__storage_type(0) << (__bits_per_word - __n);
+            __storage_type __b = *--__last.__seg_ & __m;
+            *--__result.__seg_ &= ~__m;
+            *__result.__seg_ |= __b;
+            __result.__ctz_ = static_cast<unsigned>(-__n & (__bits_per_word - 1));
+        }
+    }
+    return __result;
+}
+
+template <class _Cp, bool _IsConst>
+__bit_iterator<_Cp, false>
+__copy_backward_unaligned(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last,
+                                                       __bit_iterator<_Cp, false> __result)
+{
+    typedef __bit_iterator<_Cp, _IsConst> _In;
+    typedef  typename _In::difference_type difference_type;
+    typedef typename _In::__storage_type __storage_type;
+    static const unsigned __bits_per_word = _In::__bits_per_word;
+    difference_type __n = __last - __first;
+    if (__n > 0)
+    {
+        // do first word
+        if (__last.__ctz_ != 0)
+        {
+            difference_type __dn = _VSTD::min(static_cast<difference_type>(__last.__ctz_), __n);
+            __n -= __dn;
+            unsigned __clz_l = __bits_per_word - __last.__ctz_;
+            __storage_type __m = (~__storage_type(0) << (__last.__ctz_ - __dn)) & (~__storage_type(0) >> __clz_l);
+            __storage_type __b = *__last.__seg_ & __m;
+            unsigned __clz_r = __bits_per_word - __result.__ctz_;
+            __storage_type __ddn = _VSTD::min(__dn, static_cast<difference_type>(__result.__ctz_));
+            if (__ddn > 0)
+            {
+                __m = (~__storage_type(0) << (__result.__ctz_ - __ddn)) & (~__storage_type(0) >> __clz_r);
+                *__result.__seg_ &= ~__m;
+                if (__result.__ctz_ > __last.__ctz_)
+                    *__result.__seg_ |= __b << (__result.__ctz_ - __last.__ctz_);
+                else
+                    *__result.__seg_ |= __b >> (__last.__ctz_ - __result.__ctz_);
+                __result.__ctz_ = static_cast<unsigned>(((-__ddn & (__bits_per_word - 1)) +
+                                                         __result.__ctz_)  % __bits_per_word);
+                __dn -= __ddn;
+            }
+            if (__dn > 0)
+            {
+                // __result.__ctz_ == 0
+                --__result.__seg_;
+                __result.__ctz_ = static_cast<unsigned>(-__dn & (__bits_per_word - 1));
+                __m = ~__storage_type(0) << __result.__ctz_;
+                *__result.__seg_ &= ~__m;
+                __last.__ctz_ -= __dn + __ddn;
+                *__result.__seg_ |= __b << (__result.__ctz_ - __last.__ctz_);
+            }
+            // __last.__ctz_ = 0
+         }
+        // __last.__ctz_ == 0 || __n == 0
+        // __result.__ctz_ != 0 || __n == 0
+        // do middle words
+        unsigned __clz_r = __bits_per_word - __result.__ctz_;
+        __storage_type __m = ~__storage_type(0) >> __clz_r;
+        for (; __n >= __bits_per_word; __n -= __bits_per_word)
+        {
+            __storage_type __b = *--__last.__seg_;
+            *__result.__seg_ &= ~__m;
+            *__result.__seg_ |= __b >> __clz_r;
+            *--__result.__seg_ &= __m;
+            *__result.__seg_ |= __b << __result.__ctz_;
+        }
+        // do last word
+        if (__n > 0)
+        {
+            __m = ~__storage_type(0) << (__bits_per_word - __n);
+            __storage_type __b = *--__last.__seg_ & __m;
+            __clz_r = __bits_per_word - __result.__ctz_;
+            __storage_type __dn = _VSTD::min(__n, static_cast<difference_type>(__result.__ctz_));
+            __m = (~__storage_type(0) << (__result.__ctz_ - __dn)) & (~__storage_type(0) >> __clz_r);
+            *__result.__seg_ &= ~__m;
+            *__result.__seg_ |= __b >> (__bits_per_word - __result.__ctz_);
+            __result.__ctz_ = static_cast<unsigned>(((-__dn & (__bits_per_word - 1)) +
+                                                     __result.__ctz_)  % __bits_per_word);
+            __n -= __dn;
+            if (__n > 0)
+            {
+                // __result.__ctz_ == 0
+                --__result.__seg_;
+                __result.__ctz_ = static_cast<unsigned>(-__n & (__bits_per_word - 1));
+                __m = ~__storage_type(0) << __result.__ctz_;
+                *__result.__seg_ &= ~__m;
+                *__result.__seg_ |= __b << (__result.__ctz_ - (__bits_per_word - __n - __dn));
+            }
+        }
+    }
+    return __result;
+}
+
+template <class _Cp, bool _IsConst>
+inline _LIBCPP_INLINE_VISIBILITY
+__bit_iterator<_Cp, false>
+copy_backward(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, __bit_iterator<_Cp, false> __result)
+{
+    if (__last.__ctz_ == __result.__ctz_)
+        return __copy_backward_aligned(__first, __last, __result);
+    return __copy_backward_unaligned(__first, __last, __result);
+}
+
+// move
+
+template <class _Cp, bool _IsConst>
+inline _LIBCPP_INLINE_VISIBILITY
+__bit_iterator<_Cp, false>
+move(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, __bit_iterator<_Cp, false> __result)
+{
+    return _VSTD::copy(__first, __last, __result);
+}
+
+// move_backward
+
+template <class _Cp, bool _IsConst>
+inline _LIBCPP_INLINE_VISIBILITY
+__bit_iterator<_Cp, false>
+move_backward(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, __bit_iterator<_Cp, false> __result)
+{
+    return _VSTD::copy_backward(__first, __last, __result);
+}
+
+// swap_ranges
+
+template <class __C1, class __C2>
+__bit_iterator<__C2, false>
+__swap_ranges_aligned(__bit_iterator<__C1, false> __first, __bit_iterator<__C1, false> __last,
+                      __bit_iterator<__C2, false> __result)
+{
+    typedef __bit_iterator<__C1, false> _I1;
+    typedef  typename _I1::difference_type difference_type;
+    typedef typename _I1::__storage_type __storage_type;
+    static const unsigned __bits_per_word = _I1::__bits_per_word;
+    difference_type __n = __last - __first;
+    if (__n > 0)
+    {
+        // do first word
+        if (__first.__ctz_ != 0)
+        {
+            unsigned __clz = __bits_per_word - __first.__ctz_;
+            difference_type __dn = _VSTD::min(static_cast<difference_type>(__clz), __n);
+            __n -= __dn;
+            __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz - __dn));
+            __storage_type __b1 = *__first.__seg_ & __m;
+            *__first.__seg_ &= ~__m;
+            __storage_type __b2 = *__result.__seg_ & __m;
+            *__result.__seg_ &= ~__m;
+            *__result.__seg_ |= __b1;
+            *__first.__seg_  |= __b2;
+            __result.__seg_ += (__dn + __result.__ctz_) / __bits_per_word;
+            __result.__ctz_ = static_cast<unsigned>((__dn + __result.__ctz_)  % __bits_per_word);
+            ++__first.__seg_;
+            // __first.__ctz_ = 0;
+        }
+        // __first.__ctz_ == 0;
+        // do middle words
+        for (; __n >= __bits_per_word; __n -= __bits_per_word, ++__first.__seg_, ++__result.__seg_)
+            swap(*__first.__seg_, *__result.__seg_);
+        // do last word
+        if (__n > 0)
+        {
+            __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
+            __storage_type __b1 = *__first.__seg_ & __m;
+            *__first.__seg_ &= ~__m;
+            __storage_type __b2 = *__result.__seg_ & __m;
+            *__result.__seg_ &= ~__m;
+            *__result.__seg_ |= __b1;
+            *__first.__seg_  |= __b2;
+            __result.__ctz_ = static_cast<unsigned>(__n);
+        }
+    }
+    return __result;
+}
+
+template <class __C1, class __C2>
+__bit_iterator<__C2, false>
+__swap_ranges_unaligned(__bit_iterator<__C1, false> __first, __bit_iterator<__C1, false> __last,
+                        __bit_iterator<__C2, false> __result)
+{
+    typedef __bit_iterator<__C1, false> _I1;
+    typedef  typename _I1::difference_type difference_type;
+    typedef typename _I1::__storage_type __storage_type;
+    static const unsigned __bits_per_word = _I1::__bits_per_word;
+    difference_type __n = __last - __first;
+    if (__n > 0)
+    {
+        // do first word
+        if (__first.__ctz_ != 0)
+        {
+            unsigned __clz_f = __bits_per_word - __first.__ctz_;
+            difference_type __dn = _VSTD::min(static_cast<difference_type>(__clz_f), __n);
+            __n -= __dn;
+            __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
+            __storage_type __b1 = *__first.__seg_ & __m;
+            *__first.__seg_ &= ~__m;
+            unsigned __clz_r = __bits_per_word - __result.__ctz_;
+            __storage_type __ddn = _VSTD::min<__storage_type>(__dn, __clz_r);
+            __m = (~__storage_type(0) << __result.__ctz_) & (~__storage_type(0) >> (__clz_r - __ddn));
+            __storage_type __b2 = *__result.__seg_ & __m;
+            *__result.__seg_ &= ~__m;
+            if (__result.__ctz_ > __first.__ctz_)
+            {
+                unsigned __s = __result.__ctz_ - __first.__ctz_;
+                *__result.__seg_ |= __b1 << __s;
+                *__first.__seg_  |= __b2 >> __s;
+            }
+            else
+            {
+                unsigned __s = __first.__ctz_ - __result.__ctz_;
+                *__result.__seg_ |= __b1 >> __s;
+                *__first.__seg_  |= __b2 << __s;
+            }
+            __result.__seg_ += (__ddn + __result.__ctz_) / __bits_per_word;
+            __result.__ctz_ = static_cast<unsigned>((__ddn + __result.__ctz_)  % __bits_per_word);
+            __dn -= __ddn;
+            if (__dn > 0)
+            {
+                __m = ~__storage_type(0) >> (__bits_per_word - __dn);
+                __b2 = *__result.__seg_ & __m;
+                *__result.__seg_ &= ~__m;
+                unsigned __s = __first.__ctz_ + __ddn;
+                *__result.__seg_ |= __b1 >> __s;
+                *__first.__seg_  |= __b2 << __s;
+                __result.__ctz_ = static_cast<unsigned>(__dn);
+            }
+            ++__first.__seg_;
+            // __first.__ctz_ = 0;
+        }
+        // __first.__ctz_ == 0;
+        // do middle words
+        __storage_type __m = ~__storage_type(0) << __result.__ctz_;
+        unsigned __clz_r = __bits_per_word - __result.__ctz_;
+        for (; __n >= __bits_per_word; __n -= __bits_per_word, ++__first.__seg_)
+        {
+            __storage_type __b1 = *__first.__seg_;
+            __storage_type __b2 = *__result.__seg_ & __m;
+            *__result.__seg_ &= ~__m;
+            *__result.__seg_ |= __b1 << __result.__ctz_;
+            *__first.__seg_  = __b2 >> __result.__ctz_;
+            ++__result.__seg_;
+            __b2 = *__result.__seg_ & ~__m;
+            *__result.__seg_ &= __m;
+            *__result.__seg_ |= __b1 >> __clz_r;
+            *__first.__seg_  |= __b2 << __clz_r;
+        }
+        // do last word
+        if (__n > 0)
+        {
+            __m = ~__storage_type(0) >> (__bits_per_word - __n);
+            __storage_type __b1 = *__first.__seg_ & __m;
+            *__first.__seg_ &= ~__m;
+            __storage_type __dn = _VSTD::min<__storage_type>(__n, __clz_r);
+            __m = (~__storage_type(0) << __result.__ctz_) & (~__storage_type(0) >> (__clz_r - __dn));
+            __storage_type __b2 = *__result.__seg_ & __m;
+            *__result.__seg_ &= ~__m;
+            *__result.__seg_ |= __b1 << __result.__ctz_;
+            *__first.__seg_  |= __b2 >> __result.__ctz_;
+            __result.__seg_ += (__dn + __result.__ctz_) / __bits_per_word;
+            __result.__ctz_ = static_cast<unsigned>((__dn + __result.__ctz_)  % __bits_per_word);
+            __n -= __dn;
+            if (__n > 0)
+            {
+                __m = ~__storage_type(0) >> (__bits_per_word - __n);
+                __b2 = *__result.__seg_ & __m;
+                *__result.__seg_ &= ~__m;
+                *__result.__seg_ |= __b1 >> __dn;
+                *__first.__seg_  |= __b2 << __dn;
+                __result.__ctz_ = static_cast<unsigned>(__n);
+            }
+        }
+    }
+    return __result;
+}
+
+template <class __C1, class __C2>
+inline _LIBCPP_INLINE_VISIBILITY
+__bit_iterator<__C2, false>
+swap_ranges(__bit_iterator<__C1, false> __first1, __bit_iterator<__C1, false> __last1,
+            __bit_iterator<__C2, false> __first2)
+{
+    if (__first1.__ctz_ == __first2.__ctz_)
+        return __swap_ranges_aligned(__first1, __last1, __first2);
+    return __swap_ranges_unaligned(__first1, __last1, __first2);
+}
+
+// rotate
+
+template <class _Cp>
+struct __bit_array
+{
+    typedef typename _Cp::difference_type difference_type;
+    typedef typename _Cp::__storage_type  __storage_type;
+    typedef typename _Cp::__storage_pointer __storage_pointer;
+    typedef typename _Cp::iterator        iterator;
+    static const unsigned __bits_per_word = _Cp::__bits_per_word;
+    static const unsigned _Np = 4;
+
+    difference_type __size_;
+    __storage_type __word_[_Np];
+
+    _LIBCPP_INLINE_VISIBILITY static difference_type capacity()
+        {return static_cast<difference_type>(_Np * __bits_per_word);}
+    _LIBCPP_INLINE_VISIBILITY explicit __bit_array(difference_type __s) : __size_(__s) {}
+    _LIBCPP_INLINE_VISIBILITY iterator begin()
+    {
+        return iterator(pointer_traits<__storage_pointer>::pointer_to(__word_[0]), 0);
+    }
+    _LIBCPP_INLINE_VISIBILITY iterator end()
+    {
+        return iterator(pointer_traits<__storage_pointer>::pointer_to(__word_[0]) + __size_ / __bits_per_word,
+                                                  static_cast<unsigned>(__size_ % __bits_per_word));
+    }
+};
+
+template <class _Cp>
+__bit_iterator<_Cp, false>
+rotate(__bit_iterator<_Cp, false> __first, __bit_iterator<_Cp, false> __middle, __bit_iterator<_Cp, false> __last)
+{
+    typedef __bit_iterator<_Cp, false> _I1;
+    typedef  typename _I1::difference_type difference_type;
+    difference_type __d1 = __middle - __first;
+    difference_type __d2 = __last - __middle;
+    _I1 __r = __first + __d2;
+    while (__d1 != 0 && __d2 != 0)
+    {
+        if (__d1 <= __d2)
+        {
+            if (__d1 <= __bit_array<_Cp>::capacity())
+            {
+                __bit_array<_Cp> __b(__d1);
+                _VSTD::copy(__first, __middle, __b.begin());
+                _VSTD::copy(__b.begin(), __b.end(), _VSTD::copy(__middle, __last, __first));
+                break;
+            }
+            else
+            {
+                __bit_iterator<_Cp, false> __mp = _VSTD::swap_ranges(__first, __middle, __middle);
+                __first = __middle;
+                __middle = __mp;
+                __d2 -= __d1;
+            }
+        }
+        else
+        {
+            if (__d2 <= __bit_array<_Cp>::capacity())
+            {
+                __bit_array<_Cp> __b(__d2);
+                _VSTD::copy(__middle, __last, __b.begin());
+                _VSTD::copy_backward(__b.begin(), __b.end(), _VSTD::copy_backward(__first, __middle, __last));
+                break;
+            }
+            else
+            {
+                __bit_iterator<_Cp, false> __mp = __first + __d2;
+                _VSTD::swap_ranges(__first, __mp, __middle);
+                __first = __mp;
+                __d1 -= __d2;
+            }
+        }
+    }
+    return __r;
+}
+
+// equal
+
+template <class _Cp, bool _IC1, bool _IC2>
+bool
+__equal_unaligned(__bit_iterator<_Cp, _IC1> __first1, __bit_iterator<_Cp, _IC1> __last1,
+                  __bit_iterator<_Cp, _IC2> __first2)
+{
+    typedef __bit_iterator<_Cp, _IC1> _It;
+    typedef  typename _It::difference_type difference_type;
+    typedef typename _It::__storage_type __storage_type;
+    static const unsigned __bits_per_word = _It::__bits_per_word;
+    difference_type __n = __last1 - __first1;
+    if (__n > 0)
+    {
+        // do first word
+        if (__first1.__ctz_ != 0)
+        {
+            unsigned __clz_f = __bits_per_word - __first1.__ctz_;
+            difference_type __dn = _VSTD::min(static_cast<difference_type>(__clz_f), __n);
+            __n -= __dn;
+            __storage_type __m = (~__storage_type(0) << __first1.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
+            __storage_type __b = *__first1.__seg_ & __m;
+            unsigned __clz_r = __bits_per_word - __first2.__ctz_;
+            __storage_type __ddn = _VSTD::min<__storage_type>(__dn, __clz_r);
+            __m = (~__storage_type(0) << __first2.__ctz_) & (~__storage_type(0) >> (__clz_r - __ddn));
+            if (__first2.__ctz_ > __first1.__ctz_)
+            {
+                if ((*__first2.__seg_ & __m) != (__b << (__first2.__ctz_ - __first1.__ctz_)))
+                    return false;
+            }
+            else
+            {
+                if ((*__first2.__seg_ & __m) != (__b >> (__first1.__ctz_ - __first2.__ctz_)))
+                    return false;
+            }
+            __first2.__seg_ += (__ddn + __first2.__ctz_) / __bits_per_word;
+            __first2.__ctz_ = static_cast<unsigned>((__ddn + __first2.__ctz_)  % __bits_per_word);
+            __dn -= __ddn;
+            if (__dn > 0)
+            {
+                __m = ~__storage_type(0) >> (__bits_per_word - __dn);
+                if ((*__first2.__seg_ & __m) != (__b >> (__first1.__ctz_ + __ddn)))
+                    return false;
+                __first2.__ctz_ = static_cast<unsigned>(__dn);
+            }
+            ++__first1.__seg_;
+            // __first1.__ctz_ = 0;
+        }
+        // __first1.__ctz_ == 0;
+        // do middle words
+        unsigned __clz_r = __bits_per_word - __first2.__ctz_;
+        __storage_type __m = ~__storage_type(0) << __first2.__ctz_;
+        for (; __n >= __bits_per_word; __n -= __bits_per_word, ++__first1.__seg_)
+        {
+            __storage_type __b = *__first1.__seg_;
+            if ((*__first2.__seg_ & __m) != (__b << __first2.__ctz_))
+                return false;
+            ++__first2.__seg_;
+            if ((*__first2.__seg_ & ~__m) != (__b >> __clz_r))
+                return false;
+        }
+        // do last word
+        if (__n > 0)
+        {
+            __m = ~__storage_type(0) >> (__bits_per_word - __n);
+            __storage_type __b = *__first1.__seg_ & __m;
+            __storage_type __dn = _VSTD::min(__n, static_cast<difference_type>(__clz_r));
+            __m = (~__storage_type(0) << __first2.__ctz_) & (~__storage_type(0) >> (__clz_r - __dn));
+            if ((*__first2.__seg_ & __m) != (__b << __first2.__ctz_))
+                return false;
+            __first2.__seg_ += (__dn + __first2.__ctz_) / __bits_per_word;
+            __first2.__ctz_ = static_cast<unsigned>((__dn + __first2.__ctz_)  % __bits_per_word);
+            __n -= __dn;
+            if (__n > 0)
+            {
+                __m = ~__storage_type(0) >> (__bits_per_word - __n);
+                if ((*__first2.__seg_ & __m) != (__b >> __dn))
+                    return false;
+            }
+        }
+    }
+    return true;
+}
+
+template <class _Cp, bool _IC1, bool _IC2>
+bool
+__equal_aligned(__bit_iterator<_Cp, _IC1> __first1, __bit_iterator<_Cp, _IC1> __last1,
+                __bit_iterator<_Cp, _IC2> __first2)
+{
+    typedef __bit_iterator<_Cp, _IC1> _It;
+    typedef  typename _It::difference_type difference_type;
+    typedef typename _It::__storage_type __storage_type;
+    static const unsigned __bits_per_word = _It::__bits_per_word;
+    difference_type __n = __last1 - __first1;
+    if (__n > 0)
+    {
+        // do first word
+        if (__first1.__ctz_ != 0)
+        {
+            unsigned __clz = __bits_per_word - __first1.__ctz_;
+            difference_type __dn = _VSTD::min(static_cast<difference_type>(__clz), __n);
+            __n -= __dn;
+            __storage_type __m = (~__storage_type(0) << __first1.__ctz_) & (~__storage_type(0) >> (__clz - __dn));
+            if ((*__first2.__seg_ & __m) != (*__first1.__seg_ & __m))
+                return false;
+            ++__first2.__seg_;
+            ++__first1.__seg_;
+            // __first1.__ctz_ = 0;
+            // __first2.__ctz_ = 0;
+        }
+        // __first1.__ctz_ == 0;
+        // __first2.__ctz_ == 0;
+        // do middle words
+        for (; __n >= __bits_per_word; __n -= __bits_per_word, ++__first1.__seg_, ++__first2.__seg_)
+            if (*__first2.__seg_ != *__first1.__seg_)
+                return false;
+        // do last word
+        if (__n > 0)
+        {
+            __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
+            if ((*__first2.__seg_ & __m) != (*__first1.__seg_ & __m))
+                return false;
+        }
+    }
+    return true;
+}
+
+template <class _Cp, bool _IC1, bool _IC2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+equal(__bit_iterator<_Cp, _IC1> __first1, __bit_iterator<_Cp, _IC1> __last1, __bit_iterator<_Cp, _IC2> __first2)
+{
+    if (__first1.__ctz_ == __first2.__ctz_)
+        return __equal_aligned(__first1, __last1, __first2);
+    return __equal_unaligned(__first1, __last1, __first2);
+}
+
+template <class _Cp, bool _IsConst,
+          typename _Cp::__storage_type>
+class __bit_iterator
+{
+public:
+    typedef typename _Cp::difference_type                                                          difference_type;
+    typedef bool                                                                                  value_type;
+    typedef __bit_iterator                                                                        pointer;
+    typedef typename conditional<_IsConst, __bit_const_reference<_Cp>, __bit_reference<_Cp> >::type reference;
+    typedef random_access_iterator_tag                                                            iterator_category;
+
+private:
+    typedef typename _Cp::__storage_type                                           __storage_type;
+    typedef typename conditional<_IsConst, typename _Cp::__const_storage_pointer,
+                                           typename _Cp::__storage_pointer>::type  __storage_pointer;
+    static const unsigned __bits_per_word = _Cp::__bits_per_word;
+
+    __storage_pointer __seg_;
+    unsigned          __ctz_;
+
+public:
+    _LIBCPP_INLINE_VISIBILITY __bit_iterator() _NOEXCEPT
+#if _LIBCPP_STD_VER > 11
+    : __seg_(nullptr), __ctz_(0)
+#endif
+    {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __bit_iterator(const __bit_iterator<_Cp, false>& __it) _NOEXCEPT
+        : __seg_(__it.__seg_), __ctz_(__it.__ctz_) {}
+
+    _LIBCPP_INLINE_VISIBILITY reference operator*() const _NOEXCEPT
+        {return reference(__seg_, __storage_type(1) << __ctz_);}
+
+    _LIBCPP_INLINE_VISIBILITY __bit_iterator& operator++()
+    {
+        if (__ctz_ != __bits_per_word-1)
+            ++__ctz_;
+        else
+        {
+            __ctz_ = 0;
+            ++__seg_;
+        }
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY __bit_iterator operator++(int)
+    {
+        __bit_iterator __tmp = *this;
+        ++(*this);
+        return __tmp;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY __bit_iterator& operator--()
+    {
+        if (__ctz_ != 0)
+            --__ctz_;
+        else
+        {
+            __ctz_ = __bits_per_word - 1;
+            --__seg_;
+        }
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY __bit_iterator operator--(int)
+    {
+        __bit_iterator __tmp = *this;
+        --(*this);
+        return __tmp;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY __bit_iterator& operator+=(difference_type __n)
+    {
+        if (__n >= 0)
+            __seg_ += (__n + __ctz_) / __bits_per_word;
+        else
+            __seg_ += static_cast<difference_type>(__n - __bits_per_word + __ctz_ + 1)
+                    / static_cast<difference_type>(__bits_per_word);
+        __n &= (__bits_per_word - 1);
+        __ctz_ = static_cast<unsigned>((__n + __ctz_)  % __bits_per_word);
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY __bit_iterator& operator-=(difference_type __n)
+    {
+        return *this += -__n;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY __bit_iterator operator+(difference_type __n) const
+    {
+        __bit_iterator __t(*this);
+        __t += __n;
+        return __t;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY __bit_iterator operator-(difference_type __n) const
+    {
+        __bit_iterator __t(*this);
+        __t -= __n;
+        return __t;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    friend __bit_iterator operator+(difference_type __n, const __bit_iterator& __it) {return __it + __n;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    friend difference_type operator-(const __bit_iterator& __x, const __bit_iterator& __y)
+        {return (__x.__seg_ - __y.__seg_) * __bits_per_word + __x.__ctz_ - __y.__ctz_;}
+
+    _LIBCPP_INLINE_VISIBILITY reference operator[](difference_type __n) const {return *(*this + __n);}
+
+    _LIBCPP_INLINE_VISIBILITY friend bool operator==(const __bit_iterator& __x, const __bit_iterator& __y)
+        {return __x.__seg_ == __y.__seg_ && __x.__ctz_ == __y.__ctz_;}
+
+    _LIBCPP_INLINE_VISIBILITY friend bool operator!=(const __bit_iterator& __x, const __bit_iterator& __y)
+        {return !(__x == __y);}
+
+    _LIBCPP_INLINE_VISIBILITY friend bool operator<(const __bit_iterator& __x, const __bit_iterator& __y)
+        {return __x.__seg_ < __y.__seg_ || (__x.__seg_ == __y.__seg_ && __x.__ctz_ < __y.__ctz_);}
+
+    _LIBCPP_INLINE_VISIBILITY friend bool operator>(const __bit_iterator& __x, const __bit_iterator& __y)
+        {return __y < __x;}
+
+    _LIBCPP_INLINE_VISIBILITY friend bool operator<=(const __bit_iterator& __x, const __bit_iterator& __y)
+        {return !(__y < __x);}
+
+    _LIBCPP_INLINE_VISIBILITY friend bool operator>=(const __bit_iterator& __x, const __bit_iterator& __y)
+        {return !(__x < __y);}
+
+private:
+    _LIBCPP_INLINE_VISIBILITY
+    __bit_iterator(__storage_pointer __s, unsigned __ctz) _NOEXCEPT
+        : __seg_(__s), __ctz_(__ctz) {}
+
+#if defined(__clang__) || defined(__IBMCPP__) || defined(_LIBCPP_MSVC)
+    friend typename _Cp::__self;
+#else
+    friend class _Cp::__self;
+#endif
+    friend class __bit_reference<_Cp>;
+    friend class __bit_const_reference<_Cp>;
+    friend class __bit_iterator<_Cp, true>;
+    template <class _Dp> friend struct __bit_array;
+    template <class _Dp> friend void __fill_n_false(__bit_iterator<_Dp, false> __first, typename _Dp::size_type __n);
+    template <class _Dp> friend void __fill_n_true(__bit_iterator<_Dp, false> __first, typename _Dp::size_type __n);
+    template <class _Dp, bool _IC> friend __bit_iterator<_Dp, false> __copy_aligned(__bit_iterator<_Dp, _IC> __first,
+                                                                                  __bit_iterator<_Dp, _IC> __last,
+                                                                                  __bit_iterator<_Dp, false> __result);
+    template <class _Dp, bool _IC> friend __bit_iterator<_Dp, false> __copy_unaligned(__bit_iterator<_Dp, _IC> __first,
+                                                                                    __bit_iterator<_Dp, _IC> __last,
+                                                                                    __bit_iterator<_Dp, false> __result);
+    template <class _Dp, bool _IC> friend __bit_iterator<_Dp, false> copy(__bit_iterator<_Dp, _IC> __first,
+                                                                        __bit_iterator<_Dp, _IC> __last,
+                                                                        __bit_iterator<_Dp, false> __result);
+    template <class _Dp, bool _IC> friend __bit_iterator<_Dp, false> __copy_backward_aligned(__bit_iterator<_Dp, _IC> __first,
+                                                                                           __bit_iterator<_Dp, _IC> __last,
+                                                                                           __bit_iterator<_Dp, false> __result);
+    template <class _Dp, bool _IC> friend __bit_iterator<_Dp, false> __copy_backward_unaligned(__bit_iterator<_Dp, _IC> __first,
+                                                                                             __bit_iterator<_Dp, _IC> __last,
+                                                                                             __bit_iterator<_Dp, false> __result);
+    template <class _Dp, bool _IC> friend __bit_iterator<_Dp, false> copy_backward(__bit_iterator<_Dp, _IC> __first,
+                                                                                 __bit_iterator<_Dp, _IC> __last,
+                                                                                 __bit_iterator<_Dp, false> __result);
+    template <class __C1, class __C2>friend __bit_iterator<__C2, false> __swap_ranges_aligned(__bit_iterator<__C1, false>,
+                                                                                           __bit_iterator<__C1, false>,
+                                                                                           __bit_iterator<__C2, false>);
+    template <class __C1, class __C2>friend __bit_iterator<__C2, false> __swap_ranges_unaligned(__bit_iterator<__C1, false>,
+                                                                                             __bit_iterator<__C1, false>,
+                                                                                             __bit_iterator<__C2, false>);
+    template <class __C1, class __C2>friend __bit_iterator<__C2, false> swap_ranges(__bit_iterator<__C1, false>,
+                                                                                 __bit_iterator<__C1, false>,
+                                                                                 __bit_iterator<__C2, false>);
+    template <class _Dp> friend __bit_iterator<_Dp, false> rotate(__bit_iterator<_Dp, false>,
+                                                                __bit_iterator<_Dp, false>,
+                                                                __bit_iterator<_Dp, false>);
+    template <class _Dp, bool _IC1, bool _IC2> friend bool __equal_aligned(__bit_iterator<_Dp, _IC1>,
+                                                    __bit_iterator<_Dp, _IC1>,
+                                                    __bit_iterator<_Dp, _IC2>);
+    template <class _Dp, bool _IC1, bool _IC2> friend bool __equal_unaligned(__bit_iterator<_Dp, _IC1>,
+                                                      __bit_iterator<_Dp, _IC1>,
+                                                      __bit_iterator<_Dp, _IC2>);
+    template <class _Dp, bool _IC1, bool _IC2> friend bool equal(__bit_iterator<_Dp, _IC1>,
+                                                                __bit_iterator<_Dp, _IC1>,
+                                                                __bit_iterator<_Dp, _IC2>);
+    template <class _Dp, bool _IC> friend __bit_iterator<_Dp, _IC> __find_bool_true(__bit_iterator<_Dp, _IC>,
+                                                                          typename _Dp::size_type);
+    template <class _Dp, bool _IC> friend __bit_iterator<_Dp, _IC> __find_bool_false(__bit_iterator<_Dp, _IC>,
+                                                                           typename _Dp::size_type);
+    template <class _Dp, bool _IC> friend typename __bit_iterator<_Dp, _IC>::difference_type
+                   __count_bool_true(__bit_iterator<_Dp, _IC>, typename _Dp::size_type);
+    template <class _Dp, bool _IC> friend typename __bit_iterator<_Dp, _IC>::difference_type
+                   __count_bool_false(__bit_iterator<_Dp, _IC>, typename _Dp::size_type);
+};
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP___BIT_REFERENCE

diff --git a/libcxx/include/__config b/libcxx/include/__config
new file mode 100644
index 0000000..e001215
--- /dev/null
+++ b/libcxx/include/__config

@@ -0,0 +1,770 @@
+// -*- C++ -*-
+//===--------------------------- __config ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CONFIG
+#define _LIBCPP_CONFIG
+
+#if !defined(_MSC_VER) || defined(__clang__)
+#pragma GCC system_header
+#endif
+
+#ifdef __GNUC__
+#define _GNUC_VER (__GNUC__ * 100 + __GNUC_MINOR__)
+#else
+#define _GNUC_VER 0
+#endif
+
+#define _LIBCPP_VERSION 3800
+
+#define _LIBCPP_ABI_VERSION 1
+
+#define _LIBCPP_CONCAT1(_LIBCPP_X,_LIBCPP_Y) _LIBCPP_X##_LIBCPP_Y
+#define _LIBCPP_CONCAT(_LIBCPP_X,_LIBCPP_Y) _LIBCPP_CONCAT1(_LIBCPP_X,_LIBCPP_Y)
+
+#define _LIBCPP_NAMESPACE _LIBCPP_CONCAT(__,_LIBCPP_ABI_VERSION)
+
+
+#ifndef __has_attribute
+#define __has_attribute(__x) 0
+#endif
+#ifndef __has_builtin
+#define __has_builtin(__x) 0
+#endif
+#ifndef __has_feature
+#define __has_feature(__x) 0
+#endif
+// '__is_identifier' returns '0' if '__x' is a reserved identifier provided by
+// the compiler and '1' otherwise.
+#ifndef __is_identifier
+#define __is_identifier(__x) 1
+#endif
+
+
+#ifdef __LITTLE_ENDIAN__
+#if __LITTLE_ENDIAN__
+#define _LIBCPP_LITTLE_ENDIAN 1
+#define _LIBCPP_BIG_ENDIAN    0
+#endif  // __LITTLE_ENDIAN__
+#endif  // __LITTLE_ENDIAN__
+
+#ifdef __BIG_ENDIAN__
+#if __BIG_ENDIAN__
+#define _LIBCPP_LITTLE_ENDIAN 0
+#define _LIBCPP_BIG_ENDIAN    1
+#endif  // __BIG_ENDIAN__
+#endif  // __BIG_ENDIAN__
+
+#ifdef __FreeBSD__
+# include <sys/endian.h>
+#  if _BYTE_ORDER == _LITTLE_ENDIAN
+#   define _LIBCPP_LITTLE_ENDIAN 1
+#   define _LIBCPP_BIG_ENDIAN    0
+# else  // _BYTE_ORDER == _LITTLE_ENDIAN
+#   define _LIBCPP_LITTLE_ENDIAN 0
+#   define _LIBCPP_BIG_ENDIAN    1
+# endif  // _BYTE_ORDER == _LITTLE_ENDIAN
+# ifndef __LONG_LONG_SUPPORTED
+#  define _LIBCPP_HAS_NO_LONG_LONG
+# endif  // __LONG_LONG_SUPPORTED
+#endif  // __FreeBSD__
+
+#ifdef __NetBSD__
+# include <sys/endian.h>
+#  if _BYTE_ORDER == _LITTLE_ENDIAN
+#   define _LIBCPP_LITTLE_ENDIAN 1
+#   define _LIBCPP_BIG_ENDIAN    0
+# else  // _BYTE_ORDER == _LITTLE_ENDIAN
+#   define _LIBCPP_LITTLE_ENDIAN 0
+#   define _LIBCPP_BIG_ENDIAN    1
+# endif  // _BYTE_ORDER == _LITTLE_ENDIAN
+# define _LIBCPP_HAS_QUICK_EXIT
+#endif  // __NetBSD__
+
+#ifdef _WIN32
+#  define _LIBCPP_LITTLE_ENDIAN 1
+#  define _LIBCPP_BIG_ENDIAN    0
+// Compiler intrinsics (MSVC)
+#if defined(_MSC_VER) && _MSC_VER >= 1400
+#    define _LIBCPP_HAS_IS_BASE_OF
+#  endif
+#  if defined(_MSC_VER) && !defined(__clang__)
+#    define _LIBCPP_MSVC // Using Microsoft Visual C++ compiler
+#    define _LIBCPP_TOSTRING2(x) #x
+#    define _LIBCPP_TOSTRING(x) _LIBCPP_TOSTRING2(x)
+#    define _LIBCPP_WARNING(x) __pragma(message(__FILE__ "(" _LIBCPP_TOSTRING(__LINE__) ") : warning note: " x))
+#  endif
+#  // If mingw not explicitly detected, assume using MS C runtime only.
+#  ifndef __MINGW32__
+#    define _LIBCPP_MSVCRT // Using Microsoft's C Runtime library
+#  endif
+#endif  // _WIN32
+
+#ifdef __sun__
+# include <sys/isa_defs.h>
+# ifdef _LITTLE_ENDIAN
+#   define _LIBCPP_LITTLE_ENDIAN 1
+#   define _LIBCPP_BIG_ENDIAN    0
+# else
+#   define _LIBCPP_LITTLE_ENDIAN 0
+#   define _LIBCPP_BIG_ENDIAN    1
+# endif
+#endif // __sun__
+
+#if defined(__CloudABI__)
+  // Certain architectures provide arc4random(). Prefer using
+  // arc4random() over /dev/{u,}random to make it possible to obtain
+  // random data even when using sandboxing mechanisms such as chroots,
+  // Capsicum, etc.
+# define _LIBCPP_USING_ARC4_RANDOM
+#elif defined(__native_client__)
+  // NaCl's sandbox (which PNaCl also runs in) doesn't allow filesystem access,
+  // including accesses to the special files under /dev. C++11's
+  // std::random_device is instead exposed through a NaCl syscall.
+# define _LIBCPP_USING_NACL_RANDOM
+#elif defined(_WIN32)
+# define _LIBCPP_USING_WIN32_RANDOM
+#else
+# define _LIBCPP_USING_DEV_RANDOM
+#endif
+
+#if !defined(_LIBCPP_LITTLE_ENDIAN) || !defined(_LIBCPP_BIG_ENDIAN)
+# include <endian.h>
+# if __BYTE_ORDER == __LITTLE_ENDIAN
+#  define _LIBCPP_LITTLE_ENDIAN 1
+#  define _LIBCPP_BIG_ENDIAN    0
+# elif __BYTE_ORDER == __BIG_ENDIAN
+#  define _LIBCPP_LITTLE_ENDIAN 0
+#  define _LIBCPP_BIG_ENDIAN    1
+# else  // __BYTE_ORDER == __BIG_ENDIAN
+#  error unable to determine endian
+# endif
+#endif  // !defined(_LIBCPP_LITTLE_ENDIAN) || !defined(_LIBCPP_BIG_ENDIAN)
+
+#ifdef _WIN32
+
+// only really useful for a DLL
+#ifdef _LIBCPP_DLL // this should be a compiler builtin define ideally...
+# ifdef cxx_EXPORTS
+#  define _LIBCPP_HIDDEN
+#  define _LIBCPP_FUNC_VIS __declspec(dllexport)
+#  define _LIBCPP_TYPE_VIS __declspec(dllexport)
+# else
+#  define _LIBCPP_HIDDEN
+#  define _LIBCPP_FUNC_VIS __declspec(dllimport)
+#  define _LIBCPP_TYPE_VIS __declspec(dllimport)
+# endif
+#else
+# define _LIBCPP_HIDDEN
+# define _LIBCPP_FUNC_VIS
+# define _LIBCPP_TYPE_VIS
+#endif
+
+#define _LIBCPP_TYPE_VIS_ONLY
+#define _LIBCPP_FUNC_VIS_ONLY
+
+#ifndef _LIBCPP_INLINE_VISIBILITY
+# ifdef _LIBCPP_MSVC
+#  define _LIBCPP_INLINE_VISIBILITY __forceinline
+# else // MinGW GCC and Clang
+#  define _LIBCPP_INLINE_VISIBILITY __attribute__ ((__always_inline__))
+# endif
+#endif
+
+#ifndef _LIBCPP_EXCEPTION_ABI
+#define _LIBCPP_EXCEPTION_ABI _LIBCPP_TYPE_VIS
+#endif
+
+#ifndef _LIBCPP_ALWAYS_INLINE
+# ifdef _LIBCPP_MSVC
+#  define _LIBCPP_ALWAYS_INLINE __forceinline
+# endif
+#endif
+
+#endif // _WIN32
+
+#ifndef _LIBCPP_HIDDEN
+#define _LIBCPP_HIDDEN __attribute__ ((__visibility__("hidden")))
+#endif
+
+#ifndef _LIBCPP_FUNC_VIS
+#define _LIBCPP_FUNC_VIS __attribute__ ((__visibility__("default")))
+#endif
+
+#ifndef _LIBCPP_TYPE_VIS
+#  if __has_attribute(__type_visibility__)
+#    define _LIBCPP_TYPE_VIS __attribute__ ((__type_visibility__("default")))
+#  else
+#    define _LIBCPP_TYPE_VIS __attribute__ ((__visibility__("default")))
+#  endif
+#endif
+
+#ifndef _LIBCPP_TYPE_VIS_ONLY
+# define _LIBCPP_TYPE_VIS_ONLY _LIBCPP_TYPE_VIS
+#endif
+
+#ifndef _LIBCPP_FUNC_VIS_ONLY
+# define _LIBCPP_FUNC_VIS_ONLY _LIBCPP_FUNC_VIS
+#endif
+
+#ifndef _LIBCPP_INLINE_VISIBILITY
+#define _LIBCPP_INLINE_VISIBILITY __attribute__ ((__visibility__("hidden"), __always_inline__))
+#endif
+
+#ifndef _LIBCPP_EXCEPTION_ABI
+#define _LIBCPP_EXCEPTION_ABI __attribute__ ((__visibility__("default")))
+#endif
+
+#ifndef _LIBCPP_ALWAYS_INLINE
+#define _LIBCPP_ALWAYS_INLINE  __attribute__ ((__visibility__("hidden"), __always_inline__))
+#endif
+
+#if defined(__clang__)
+
+#if defined(__APPLE__) && !defined(__i386__) && !defined(__x86_64__) &&        \
+    !defined(__arm__)
+#define _LIBCPP_ALTERNATE_STRING_LAYOUT
+#endif
+
+#if __has_feature(cxx_alignas)
+#  define _ALIGNAS_TYPE(x) alignas(x)
+#  define _ALIGNAS(x) alignas(x)
+#else
+#  define _ALIGNAS_TYPE(x) __attribute__((__aligned__(__alignof(x))))
+#  define _ALIGNAS(x) __attribute__((__aligned__(x)))
+#endif
+
+#if !__has_feature(cxx_alias_templates)
+#define _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+#endif
+
+#if __cplusplus < 201103L
+typedef __char16_t char16_t;
+typedef __char32_t char32_t;
+#endif
+
+#if !(__has_feature(cxx_exceptions))
+#define _LIBCPP_NO_EXCEPTIONS
+#endif
+
+#if !(__has_feature(cxx_rtti))
+#define _LIBCPP_NO_RTTI
+#endif
+
+#if !(__has_feature(cxx_strong_enums))
+#define _LIBCPP_HAS_NO_STRONG_ENUMS
+#endif
+
+#if !(__has_feature(cxx_decltype))
+#define _LIBCPP_HAS_NO_DECLTYPE
+#endif
+
+#if __has_feature(cxx_attributes)
+#  define _LIBCPP_NORETURN [[noreturn]]
+#else
+#  define _LIBCPP_NORETURN __attribute__ ((noreturn))
+#endif
+
+#define _LIBCPP_UNUSED __attribute__((__unused__))
+
+#if !(__has_feature(cxx_defaulted_functions))
+#define _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+#endif  // !(__has_feature(cxx_defaulted_functions))
+
+#if !(__has_feature(cxx_deleted_functions))
+#define _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+#endif  // !(__has_feature(cxx_deleted_functions))
+
+#if !(__has_feature(cxx_lambdas))
+#define _LIBCPP_HAS_NO_LAMBDAS
+#endif
+
+#if !(__has_feature(cxx_nullptr))
+#define _LIBCPP_HAS_NO_NULLPTR
+#endif
+
+#if !(__has_feature(cxx_rvalue_references))
+#define _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#endif
+
+#if !(__has_feature(cxx_static_assert))
+#define _LIBCPP_HAS_NO_STATIC_ASSERT
+#endif
+
+#if !(__has_feature(cxx_auto_type))
+#define _LIBCPP_HAS_NO_AUTO_TYPE
+#endif
+
+#if !(__has_feature(cxx_access_control_sfinae)) || !__has_feature(cxx_trailing_return)
+#define _LIBCPP_HAS_NO_ADVANCED_SFINAE
+#endif
+
+#if !(__has_feature(cxx_variadic_templates))
+#define _LIBCPP_HAS_NO_VARIADICS
+#endif
+
+#if !(__has_feature(cxx_trailing_return))
+#define _LIBCPP_HAS_NO_TRAILING_RETURN
+#endif
+
+#if !(__has_feature(cxx_generalized_initializers))
+#define _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+#endif
+
+#if __has_feature(is_base_of)
+#  define _LIBCPP_HAS_IS_BASE_OF
+#endif
+
+#if __has_feature(is_final)
+#  define _LIBCPP_HAS_IS_FINAL
+#endif
+
+// Objective-C++ features (opt-in)
+#if __has_feature(objc_arc)
+#define _LIBCPP_HAS_OBJC_ARC
+#endif
+
+#if __has_feature(objc_arc_weak)
+#define _LIBCPP_HAS_OBJC_ARC_WEAK
+#define _LIBCPP_HAS_NO_STRONG_ENUMS
+#endif
+
+#if !(__has_feature(cxx_constexpr))
+#define _LIBCPP_HAS_NO_CONSTEXPR
+#endif
+
+#if !(__has_feature(cxx_relaxed_constexpr))
+#define _LIBCPP_HAS_NO_CXX14_CONSTEXPR
+#endif
+
+#if !(__has_feature(cxx_variable_templates))
+#define _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
+#endif
+
+#if __ISO_C_VISIBLE >= 2011 || __cplusplus >= 201103L
+#if defined(__FreeBSD__)
+#define _LIBCPP_HAS_QUICK_EXIT
+#define _LIBCPP_HAS_C11_FEATURES
+#elif defined(__ANDROID__)
+#define _LIBCPP_HAS_QUICK_EXIT
+#elif defined(__linux__)
+#include <features.h>
+#if __GLIBC_PREREQ(2, 15)
+#define _LIBCPP_HAS_QUICK_EXIT
+#endif
+#if __GLIBC_PREREQ(2, 17)
+#define _LIBCPP_HAS_C11_FEATURES
+#endif
+#endif
+#endif
+
+#if (__has_feature(cxx_noexcept))
+#  define _NOEXCEPT noexcept
+#  define _NOEXCEPT_(x) noexcept(x)
+#  define _NOEXCEPT_OR_FALSE(x) noexcept(x)
+#else
+#  define _NOEXCEPT throw()
+#  define _NOEXCEPT_(x)
+#  define _NOEXCEPT_OR_FALSE(x) false
+#endif
+
+#if __has_feature(underlying_type)
+#  define _LIBCPP_UNDERLYING_TYPE(T) __underlying_type(T)
+#endif
+
+#if __has_feature(is_literal)
+#  define _LIBCPP_IS_LITERAL(T) __is_literal(T)
+#endif
+
+// Inline namespaces are available in Clang regardless of C++ dialect.
+#define _LIBCPP_BEGIN_NAMESPACE_STD namespace std {inline namespace _LIBCPP_NAMESPACE {
+#define _LIBCPP_END_NAMESPACE_STD  } }
+#define _VSTD std::_LIBCPP_NAMESPACE
+
+namespace std {
+  inline namespace _LIBCPP_NAMESPACE {
+  }
+}
+
+#if !defined(_LIBCPP_HAS_NO_ASAN) && !__has_feature(address_sanitizer)
+#define _LIBCPP_HAS_NO_ASAN
+#endif
+
+#elif defined(__GNUC__)
+
+#define _ALIGNAS(x) __attribute__((__aligned__(x)))
+#define _ALIGNAS_TYPE(x) __attribute__((__aligned__(__alignof(x))))
+
+#define _LIBCPP_NORETURN __attribute__((noreturn))
+
+#define _LIBCPP_UNUSED __attribute__((__unused__))
+
+#if _GNUC_VER >= 407
+#define _LIBCPP_UNDERLYING_TYPE(T) __underlying_type(T)
+#define _LIBCPP_IS_LITERAL(T) __is_literal_type(T)
+#define _LIBCPP_HAS_IS_FINAL
+#endif
+
+#if defined(__GNUC__) && _GNUC_VER >= 403
+#  define _LIBCPP_HAS_IS_BASE_OF
+#endif
+
+#if !__EXCEPTIONS
+#define _LIBCPP_NO_EXCEPTIONS
+#endif
+
+#define _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+
+// constexpr was added to GCC in 4.6.
+#if _GNUC_VER < 406
+#define _LIBCPP_HAS_NO_CONSTEXPR
+// Can only use constexpr in c++11 mode.
+#elif !defined(__GXX_EXPERIMENTAL_CXX0X__) && __cplusplus < 201103L
+#define _LIBCPP_HAS_NO_CONSTEXPR
+#endif
+
+// No version of GCC supports relaxed constexpr rules
+#define _LIBCPP_HAS_NO_CXX14_CONSTEXPR
+// GCC 5 will support variable templates
+#define _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
+
+#define _NOEXCEPT throw()
+#define _NOEXCEPT_(x)
+#define _NOEXCEPT_OR_FALSE(x) false
+
+#ifndef __GXX_EXPERIMENTAL_CXX0X__
+
+#define _LIBCPP_HAS_NO_ADVANCED_SFINAE
+#define _LIBCPP_HAS_NO_DECLTYPE
+#define _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+#define _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+#define _LIBCPP_HAS_NO_NULLPTR
+#define _LIBCPP_HAS_NO_STATIC_ASSERT
+#define _LIBCPP_HAS_NO_UNICODE_CHARS
+#define _LIBCPP_HAS_NO_VARIADICS
+#define _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#define _LIBCPP_HAS_NO_ALWAYS_INLINE_VARIADICS
+#define _LIBCPP_HAS_NO_STRONG_ENUMS
+
+#else  // __GXX_EXPERIMENTAL_CXX0X__
+
+#define _LIBCPP_HAS_NO_TRAILING_RETURN
+#define _LIBCPP_HAS_NO_ALWAYS_INLINE_VARIADICS
+
+#if _GNUC_VER < 403
+#define _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#endif
+
+#if _GNUC_VER < 403
+#define _LIBCPP_HAS_NO_STATIC_ASSERT
+#endif
+
+#if _GNUC_VER < 404
+#define _LIBCPP_HAS_NO_DECLTYPE
+#define _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+#define _LIBCPP_HAS_NO_UNICODE_CHARS
+#define _LIBCPP_HAS_NO_VARIADICS
+#define _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+#endif  // _GNUC_VER < 404
+
+#if _GNUC_VER < 406
+#define _LIBCPP_HAS_NO_NULLPTR
+#endif
+
+#if _GNUC_VER < 407
+#define _LIBCPP_HAS_NO_ADVANCED_SFINAE
+#define _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+#endif
+
+#endif  // __GXX_EXPERIMENTAL_CXX0X__
+
+#define _LIBCPP_BEGIN_NAMESPACE_STD namespace std { namespace _LIBCPP_NAMESPACE {
+#define _LIBCPP_END_NAMESPACE_STD  } }
+#define _VSTD std::_LIBCPP_NAMESPACE
+
+namespace std {
+namespace _LIBCPP_NAMESPACE {
+}
+using namespace _LIBCPP_NAMESPACE __attribute__((__strong__));
+}
+
+#if !defined(_LIBCPP_HAS_NO_ASAN) && !defined(__SANITIZE_ADDRESS__)
+#define _LIBCPP_HAS_NO_ASAN
+#endif
+
+#elif defined(_LIBCPP_MSVC)
+
+#define _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+#define _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER
+#define _LIBCPP_HAS_NO_CONSTEXPR
+#define _LIBCPP_HAS_NO_CXX14_CONSTEXPR
+#define _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
+#define _LIBCPP_HAS_NO_UNICODE_CHARS
+#define _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+#define _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+#define __alignof__ __alignof
+#define _LIBCPP_NORETURN __declspec(noreturn)
+#define _LIBCPP_UNUSED
+#define _ALIGNAS(x) __declspec(align(x))
+#define _LIBCPP_HAS_NO_VARIADICS
+
+#define _NOEXCEPT throw ()
+#define _NOEXCEPT_(x)
+#define _NOEXCEPT_OR_FALSE(x) false
+
+#define _LIBCPP_BEGIN_NAMESPACE_STD namespace std {
+#define _LIBCPP_END_NAMESPACE_STD  }
+#define _VSTD std
+
+#  define _LIBCPP_WEAK
+namespace std {
+}
+
+#define _LIBCPP_HAS_NO_ASAN
+
+#elif defined(__IBMCPP__)
+
+#define _ALIGNAS(x) __attribute__((__aligned__(x)))
+#define _ALIGNAS_TYPE(x) __attribute__((__aligned__(__alignof(x))))
+#define _ATTRIBUTE(x) __attribute__((x))
+#define _LIBCPP_NORETURN __attribute__((noreturn))
+#define _LIBCPP_UNUSED
+
+#define _NOEXCEPT throw()
+#define _NOEXCEPT_(x)
+#define _NOEXCEPT_OR_FALSE(x) false
+
+#define _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+#define _LIBCPP_HAS_NO_ADVANCED_SFINAE
+#define _LIBCPP_HAS_NO_ALWAYS_INLINE_VARIADICS
+#define _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+#define _LIBCPP_HAS_NO_NULLPTR
+#define _LIBCPP_HAS_NO_UNICODE_CHARS
+#define _LIBCPP_HAS_IS_BASE_OF
+#define _LIBCPP_HAS_IS_FINAL
+#define _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
+
+#if defined(_AIX)
+#define __MULTILOCALE_API
+#endif
+
+#define _LIBCPP_BEGIN_NAMESPACE_STD namespace std {inline namespace _LIBCPP_NAMESPACE {
+#define _LIBCPP_END_NAMESPACE_STD  } }
+#define _VSTD std::_LIBCPP_NAMESPACE
+
+namespace std {
+  inline namespace _LIBCPP_NAMESPACE {
+  }
+}
+
+#define _LIBCPP_HAS_NO_ASAN
+
+#endif // __clang__ || __GNUC__ || _MSC_VER || __IBMCPP__
+
+#ifdef _LIBCPP_HAS_NO_UNICODE_CHARS
+typedef unsigned short char16_t;
+typedef unsigned int   char32_t;
+#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
+
+#ifndef __SIZEOF_INT128__
+#define _LIBCPP_HAS_NO_INT128
+#endif
+
+#ifdef _LIBCPP_HAS_NO_STATIC_ASSERT
+
+template <bool> struct __static_assert_test;
+template <> struct __static_assert_test<true> {};
+template <unsigned> struct __static_assert_check {};
+#define static_assert(__b, __m) \
+    typedef __static_assert_check<sizeof(__static_assert_test<(__b)>)> \
+    _LIBCPP_CONCAT(__t, __LINE__)
+
+#endif  // _LIBCPP_HAS_NO_STATIC_ASSERT
+
+#ifdef _LIBCPP_HAS_NO_DECLTYPE
+// GCC 4.6 provides __decltype in all standard modes.
+#if !__is_identifier(__decltype) || _GNUC_VER >= 406
+#  define decltype(__x) __decltype(__x)
+#else
+#  define decltype(__x) __typeof__(__x)
+#endif
+#endif
+
+#ifdef _LIBCPP_HAS_NO_CONSTEXPR
+#define _LIBCPP_CONSTEXPR
+#else
+#define _LIBCPP_CONSTEXPR constexpr
+#endif
+
+#ifdef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+#define _LIBCPP_DEFAULT {}
+#else
+#define _LIBCPP_DEFAULT = default;
+#endif
+
+#ifdef __GNUC__
+#define _NOALIAS __attribute__((__malloc__))
+#else
+#define _NOALIAS
+#endif
+
+#if __has_feature(cxx_explicit_conversions) || defined(__IBMCPP__)
+#   define _LIBCPP_EXPLICIT explicit
+#else
+#   define _LIBCPP_EXPLICIT
+#endif
+
+#if !__has_builtin(__builtin_operator_new) || !__has_builtin(__builtin_operator_delete)
+#   define _LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE
+#endif
+
+#ifdef _LIBCPP_HAS_NO_STRONG_ENUMS
+#define _LIBCPP_DECLARE_STRONG_ENUM(x) struct _LIBCPP_TYPE_VIS x { enum __lx
+#define _LIBCPP_DECLARE_STRONG_ENUM_EPILOG(x) \
+    __lx __v_; \
+    _LIBCPP_ALWAYS_INLINE x(__lx __v) : __v_(__v) {} \
+    _LIBCPP_ALWAYS_INLINE explicit x(int __v) : __v_(static_cast<__lx>(__v)) {} \
+    _LIBCPP_ALWAYS_INLINE operator int() const {return __v_;} \
+    };
+#else  // _LIBCPP_HAS_NO_STRONG_ENUMS
+#define _LIBCPP_DECLARE_STRONG_ENUM(x) enum class _LIBCPP_TYPE_VIS x
+#define _LIBCPP_DECLARE_STRONG_ENUM_EPILOG(x)
+#endif  // _LIBCPP_HAS_NO_STRONG_ENUMS
+
+#ifdef _LIBCPP_DEBUG
+#   if _LIBCPP_DEBUG == 0
+#       define _LIBCPP_DEBUG_LEVEL 1
+#   elif _LIBCPP_DEBUG == 1
+#       define _LIBCPP_DEBUG_LEVEL 2
+#   else
+#       error Supported values for _LIBCPP_DEBUG are 0 and 1
+#   endif
+#   define _LIBCPP_EXTERN_TEMPLATE(...)
+#endif
+
+#ifndef _LIBCPP_EXTERN_TEMPLATE
+#define _LIBCPP_EXTERN_TEMPLATE(...)
+#endif
+
+#ifndef _LIBCPP_EXTERN_TEMPLATE2
+#define _LIBCPP_EXTERN_TEMPLATE2(...) extern template __VA_ARGS__;
+#endif
+
+#if defined(__APPLE__) && defined(__LP64__) && !defined(__x86_64__)
+#define _LIBCPP_NONUNIQUE_RTTI_BIT (1ULL << 63)
+#endif
+
+#if defined(__APPLE__) || defined(__FreeBSD__) || defined(_WIN32) || \
+    defined(__sun__) || defined(__NetBSD__) || defined(__CloudABI__)
+#define _LIBCPP_LOCALE__L_EXTENSIONS 1
+#endif
+
+#if !defined(_WIN32) && !defined(__ANDROID__) && !defined(_NEWLIB_VERSION) && \
+    !defined(__CloudABI__)
+#define _LIBCPP_HAS_CATOPEN 1
+#endif
+
+#ifdef __FreeBSD__
+#define _DECLARE_C99_LDBL_MATH 1
+#endif
+
+#if defined(__APPLE__) || defined(__FreeBSD__)
+#define _LIBCPP_HAS_DEFAULTRUNELOCALE
+#endif
+
+#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__sun__)
+#define _LIBCPP_WCTYPE_IS_MASK
+#endif
+
+#ifndef _LIBCPP_TRIVIAL_PAIR_COPY_CTOR
+#  define _LIBCPP_TRIVIAL_PAIR_COPY_CTOR 1
+#endif
+
+#ifndef _LIBCPP_STD_VER
+#  if  __cplusplus <= 201103L
+#    define _LIBCPP_STD_VER 11
+#  elif __cplusplus <= 201402L
+#    define _LIBCPP_STD_VER 14
+#  else
+#    define _LIBCPP_STD_VER 15  // current year, or date of c++17 ratification
+#  endif
+#endif  // _LIBCPP_STD_VER
+
+#if _LIBCPP_STD_VER > 11
+#define _LIBCPP_DEPRECATED [[deprecated]]
+#else
+#define _LIBCPP_DEPRECATED
+#endif
+
+#if _LIBCPP_STD_VER <= 11
+#define _LIBCPP_EXPLICIT_AFTER_CXX11
+#define _LIBCPP_DEPRECATED_AFTER_CXX11
+#else
+#define _LIBCPP_EXPLICIT_AFTER_CXX11 explicit
+#define _LIBCPP_DEPRECATED_AFTER_CXX11 [[deprecated]]
+#endif
+
+#if _LIBCPP_STD_VER > 11 && !defined(_LIBCPP_HAS_NO_CXX14_CONSTEXPR)
+#define _LIBCPP_CONSTEXPR_AFTER_CXX11 constexpr
+#else
+#define _LIBCPP_CONSTEXPR_AFTER_CXX11
+#endif
+
+#ifndef _LIBCPP_HAS_NO_ASAN
+extern "C" void __sanitizer_annotate_contiguous_container(
+  const void *, const void *, const void *, const void *);
+#endif
+
+// Try to find out if RTTI is disabled.
+// g++ and cl.exe have RTTI on by default and define a macro when it is.
+// g++ only defines the macro in 4.3.2 and onwards.
+#if !defined(_LIBCPP_NO_RTTI)
+#  if defined(__GNUG__) && ((__GNUC__ >= 5) || (__GNUC__ == 4 && \
+   (__GNUC_MINOR__ >= 3 || __GNUC_PATCHLEVEL__ >= 2))) && !defined(__GXX_RTTI)
+#    define _LIBCPP_NO_RTTI
+#  elif (defined(_MSC_VER) && !defined(__clang__)) && !defined(_CPPRTTI)
+#    define _LIBCPP_NO_RTTI
+#  endif
+#endif
+
+#ifndef _LIBCPP_WEAK
+#  define _LIBCPP_WEAK __attribute__((__weak__))
+#endif
+
+#if defined(_LIBCPP_HAS_NO_MONOTONIC_CLOCK) && !defined(_LIBCPP_HAS_NO_THREADS)
+#  error _LIBCPP_HAS_NO_MONOTONIC_CLOCK may only be defined when \
+         _LIBCPP_HAS_NO_THREADS is defined.
+#endif
+
+// Systems that use capability-based security (FreeBSD with Capsicum,
+// Nuxi CloudABI) may only provide local filesystem access (using *at()).
+// Functions like open(), rename(), unlink() and stat() should not be
+// used, as they attempt to access the global filesystem namespace.
+#ifdef __CloudABI__
+#define _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+#endif
+
+// CloudABI is intended for running networked services. Processes do not
+// have standard input and output channels.
+#ifdef __CloudABI__
+#define _LIBCPP_HAS_NO_STDIN
+#define _LIBCPP_HAS_NO_STDOUT
+#endif
+
+#if defined(__ANDROID__) || defined(__CloudABI__)
+#define _LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE
+#endif
+
+// Thread-unsafe functions such as strtok(), mbtowc() and localtime()
+// are not available.
+#ifdef __CloudABI__
+#define _LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS
+#endif
+
+#endif  // _LIBCPP_CONFIG

diff --git a/libcxx/include/__cxxabi_config.h b/libcxx/include/__cxxabi_config.h
new file mode 120000
index 0000000..431af26
--- /dev/null
+++ b/libcxx/include/__cxxabi_config.h

@@ -0,0 +1 @@
+../../libcxxabi/include/__cxxabi_config.h
\ No newline at end of file

diff --git a/libcxx/include/__debug b/libcxx/include/__debug
new file mode 100644
index 0000000..a21f9a8
--- /dev/null
+++ b/libcxx/include/__debug

@@ -0,0 +1,222 @@
+// -*- C++ -*-
+//===--------------------------- __debug ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_DEBUG_H
+#define _LIBCPP_DEBUG_H
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#if _LIBCPP_DEBUG_LEVEL >= 1
+#   include <cstdlib>
+#   include <cstdio>
+#   include <cstddef>
+#   ifndef _LIBCPP_ASSERT
+#      define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : (_VSTD::fprintf(stderr, "%s\n", m), _VSTD::abort()))
+#   endif
+#endif
+
+#ifndef _LIBCPP_ASSERT
+#   define _LIBCPP_ASSERT(x, m) ((void)0)
+#endif
+
+#if _LIBCPP_DEBUG_LEVEL >= 2
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+struct _LIBCPP_TYPE_VIS __c_node;
+
+struct _LIBCPP_TYPE_VIS __i_node
+{
+    void* __i_;
+    __i_node* __next_;
+    __c_node* __c_;
+
+#ifndef _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+    __i_node(const __i_node&) = delete;
+    __i_node& operator=(const __i_node&) = delete;
+#else
+private:
+    __i_node(const __i_node&);
+    __i_node& operator=(const __i_node&);
+public:
+#endif
+    _LIBCPP_INLINE_VISIBILITY
+    __i_node(void* __i, __i_node* __next, __c_node* __c)
+        : __i_(__i), __next_(__next), __c_(__c) {}
+    ~__i_node();
+};
+
+struct _LIBCPP_TYPE_VIS __c_node
+{
+    void* __c_;
+    __c_node* __next_;
+    __i_node** beg_;
+    __i_node** end_;
+    __i_node** cap_;
+
+#ifndef _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+    __c_node(const __c_node&) = delete;
+    __c_node& operator=(const __c_node&) = delete;
+#else
+private:
+    __c_node(const __c_node&);
+    __c_node& operator=(const __c_node&);
+public:
+#endif
+    _LIBCPP_INLINE_VISIBILITY
+    __c_node(void* __c, __c_node* __next)
+        : __c_(__c), __next_(__next), beg_(nullptr), end_(nullptr), cap_(nullptr) {}
+    virtual ~__c_node();
+
+    virtual bool __dereferenceable(const void*) const = 0;
+    virtual bool __decrementable(const void*) const = 0;
+    virtual bool __addable(const void*, ptrdiff_t) const = 0;
+    virtual bool __subscriptable(const void*, ptrdiff_t) const = 0;
+
+    void __add(__i_node* __i);
+    _LIBCPP_HIDDEN void __remove(__i_node* __i);
+};
+
+template <class _Cont>
+struct _C_node
+    : public __c_node
+{
+    _C_node(void* __c, __c_node* __n)
+        : __c_node(__c, __n) {}
+
+    virtual bool __dereferenceable(const void*) const;
+    virtual bool __decrementable(const void*) const;
+    virtual bool __addable(const void*, ptrdiff_t) const;
+    virtual bool __subscriptable(const void*, ptrdiff_t) const;
+};
+
+template <class _Cont>
+bool
+_C_node<_Cont>::__dereferenceable(const void* __i) const
+{
+    typedef typename _Cont::const_iterator iterator;
+    const iterator* __j = static_cast<const iterator*>(__i);
+    _Cont* _Cp = static_cast<_Cont*>(__c_);
+    return _Cp->__dereferenceable(__j);
+}
+
+template <class _Cont>
+bool
+_C_node<_Cont>::__decrementable(const void* __i) const
+{
+    typedef typename _Cont::const_iterator iterator;
+    const iterator* __j = static_cast<const iterator*>(__i);
+    _Cont* _Cp = static_cast<_Cont*>(__c_);
+    return _Cp->__decrementable(__j);
+}
+
+template <class _Cont>
+bool
+_C_node<_Cont>::__addable(const void* __i, ptrdiff_t __n) const
+{
+    typedef typename _Cont::const_iterator iterator;
+    const iterator* __j = static_cast<const iterator*>(__i);
+    _Cont* _Cp = static_cast<_Cont*>(__c_);
+    return _Cp->__addable(__j, __n);
+}
+
+template <class _Cont>
+bool
+_C_node<_Cont>::__subscriptable(const void* __i, ptrdiff_t __n) const
+{
+    typedef typename _Cont::const_iterator iterator;
+    const iterator* __j = static_cast<const iterator*>(__i);
+    _Cont* _Cp = static_cast<_Cont*>(__c_);
+    return _Cp->__subscriptable(__j, __n);
+}
+
+class _LIBCPP_TYPE_VIS __libcpp_db
+{
+    __c_node** __cbeg_;
+    __c_node** __cend_;
+    size_t   __csz_;
+    __i_node** __ibeg_;
+    __i_node** __iend_;
+    size_t   __isz_;
+
+    __libcpp_db();
+public:
+#ifndef _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+    __libcpp_db(const __libcpp_db&) = delete;
+    __libcpp_db& operator=(const __libcpp_db&) = delete;
+#else
+private:
+    __libcpp_db(const __libcpp_db&);
+    __libcpp_db& operator=(const __libcpp_db&);
+public:
+#endif
+    ~__libcpp_db();
+
+    class __db_c_iterator;
+    class __db_c_const_iterator;
+    class __db_i_iterator;
+    class __db_i_const_iterator;
+
+    __db_c_const_iterator __c_end() const;
+    __db_i_const_iterator __i_end() const;
+
+    template <class _Cont>
+    _LIBCPP_INLINE_VISIBILITY
+    void __insert_c(_Cont* __c)
+    {
+        __c_node* __n = __insert_c(static_cast<void*>(__c));
+        ::new(__n) _C_node<_Cont>(__n->__c_, __n->__next_);
+    }
+
+    void __insert_i(void* __i);
+    __c_node* __insert_c(void* __c);
+    void __erase_c(void* __c);
+
+    void __insert_ic(void* __i, const void* __c);
+    void __iterator_copy(void* __i, const void* __i0);
+    void __erase_i(void* __i);
+
+    void* __find_c_from_i(void* __i) const;
+    void __invalidate_all(void* __c);
+    __c_node* __find_c_and_lock(void* __c) const;
+    __c_node* __find_c(void* __c) const;
+    void unlock() const;
+
+    void swap(void* __c1, void* __c2);
+
+
+    bool __dereferenceable(const void* __i) const;
+    bool __decrementable(const void* __i) const;
+    bool __addable(const void* __i, ptrdiff_t __n) const;
+    bool __subscriptable(const void* __i, ptrdiff_t __n) const;
+    bool __less_than_comparable(const void* __i, const void* __j) const;
+private:
+    _LIBCPP_HIDDEN
+    __i_node* __insert_iterator(void* __i);
+    _LIBCPP_HIDDEN
+    __i_node* __find_iterator(const void* __i) const;
+
+    friend _LIBCPP_FUNC_VIS __libcpp_db* __get_db();
+};
+
+_LIBCPP_FUNC_VIS __libcpp_db* __get_db();
+_LIBCPP_FUNC_VIS const __libcpp_db* __get_const_db();
+
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif
+
+#endif  // _LIBCPP_DEBUG_H
+

diff --git a/libcxx/include/__functional_03 b/libcxx/include/__functional_03
new file mode 100644
index 0000000..56a8475
--- /dev/null
+++ b/libcxx/include/__functional_03

@@ -0,0 +1,1648 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_FUNCTIONAL_03
+#define _LIBCPP_FUNCTIONAL_03
+
+// manual variadic expansion for <functional>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+namespace __function {
+
+template<class _Fp> class __base;
+
+template<class _Rp>
+class __base<_Rp()>
+{
+    __base(const __base&);
+    __base& operator=(const __base&);
+public:
+    __base() {}
+    virtual ~__base() {}
+    virtual __base* __clone() const = 0;
+    virtual void __clone(__base*) const = 0;
+    virtual void destroy() = 0;
+    virtual void destroy_deallocate() = 0;
+    virtual _Rp operator()() = 0;
+#ifndef _LIBCPP_NO_RTTI
+    virtual const void* target(const type_info&) const = 0;
+    virtual const std::type_info& target_type() const = 0;
+#endif  // _LIBCPP_NO_RTTI
+};
+
+template<class _Rp, class _A0>
+class __base<_Rp(_A0)>
+{
+    __base(const __base&);
+    __base& operator=(const __base&);
+public:
+    __base() {}
+    virtual ~__base() {}
+    virtual __base* __clone() const = 0;
+    virtual void __clone(__base*) const = 0;
+    virtual void destroy() = 0;
+    virtual void destroy_deallocate() = 0;
+    virtual _Rp operator()(_A0) = 0;
+#ifndef _LIBCPP_NO_RTTI
+    virtual const void* target(const type_info&) const = 0;
+    virtual const std::type_info& target_type() const = 0;
+#endif  // _LIBCPP_NO_RTTI
+};
+
+template<class _Rp, class _A0, class _A1>
+class __base<_Rp(_A0, _A1)>
+{
+    __base(const __base&);
+    __base& operator=(const __base&);
+public:
+    __base() {}
+    virtual ~__base() {}
+    virtual __base* __clone() const = 0;
+    virtual void __clone(__base*) const = 0;
+    virtual void destroy() = 0;
+    virtual void destroy_deallocate() = 0;
+    virtual _Rp operator()(_A0, _A1) = 0;
+#ifndef _LIBCPP_NO_RTTI
+    virtual const void* target(const type_info&) const = 0;
+    virtual const std::type_info& target_type() const = 0;
+#endif  // _LIBCPP_NO_RTTI
+};
+
+template<class _Rp, class _A0, class _A1, class _A2>
+class __base<_Rp(_A0, _A1, _A2)>
+{
+    __base(const __base&);
+    __base& operator=(const __base&);
+public:
+    __base() {}
+    virtual ~__base() {}
+    virtual __base* __clone() const = 0;
+    virtual void __clone(__base*) const = 0;
+    virtual void destroy() = 0;
+    virtual void destroy_deallocate() = 0;
+    virtual _Rp operator()(_A0, _A1, _A2) = 0;
+#ifndef _LIBCPP_NO_RTTI
+    virtual const void* target(const type_info&) const = 0;
+    virtual const std::type_info& target_type() const = 0;
+#endif  // _LIBCPP_NO_RTTI
+};
+
+template<class _FD, class _Alloc, class _FB> class __func;
+
+template<class _Fp, class _Alloc, class _Rp>
+class __func<_Fp, _Alloc, _Rp()>
+    : public  __base<_Rp()>
+{
+    __compressed_pair<_Fp, _Alloc> __f_;
+public:
+    explicit __func(_Fp __f) : __f_(_VSTD::move(__f)) {}
+    explicit __func(_Fp __f, _Alloc __a) : __f_(_VSTD::move(__f), _VSTD::move(__a)) {}
+    virtual __base<_Rp()>* __clone() const;
+    virtual void __clone(__base<_Rp()>*) const;
+    virtual void destroy();
+    virtual void destroy_deallocate();
+    virtual _Rp operator()();
+#ifndef _LIBCPP_NO_RTTI
+    virtual const void* target(const type_info&) const;
+    virtual const std::type_info& target_type() const;
+#endif  // _LIBCPP_NO_RTTI
+};
+
+template<class _Fp, class _Alloc, class _Rp>
+__base<_Rp()>*
+__func<_Fp, _Alloc, _Rp()>::__clone() const
+{
+    typedef allocator_traits<_Alloc> __alloc_traits;
+    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
+    _Ap __a(__f_.second());
+    typedef __allocator_destructor<_Ap> _Dp;
+    unique_ptr<__func, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+    ::new (__hold.get()) __func(__f_.first(), _Alloc(__a));
+    return __hold.release();
+}
+
+template<class _Fp, class _Alloc, class _Rp>
+void
+__func<_Fp, _Alloc, _Rp()>::__clone(__base<_Rp()>* __p) const
+{
+    ::new (__p) __func(__f_.first(), __f_.second());
+}
+
+template<class _Fp, class _Alloc, class _Rp>
+void
+__func<_Fp, _Alloc, _Rp()>::destroy()
+{
+    __f_.~__compressed_pair<_Fp, _Alloc>();
+}
+
+template<class _Fp, class _Alloc, class _Rp>
+void
+__func<_Fp, _Alloc, _Rp()>::destroy_deallocate()
+{
+    typedef allocator_traits<_Alloc> __alloc_traits;
+    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
+    _Ap __a(__f_.second());
+    __f_.~__compressed_pair<_Fp, _Alloc>();
+    __a.deallocate(this, 1);
+}
+
+template<class _Fp, class _Alloc, class _Rp>
+_Rp
+__func<_Fp, _Alloc, _Rp()>::operator()()
+{
+    typedef __invoke_void_return_wrapper<_Rp> _Invoker;
+    return _Invoker::__call(__f_.first());
+}
+
+#ifndef _LIBCPP_NO_RTTI
+
+template<class _Fp, class _Alloc, class _Rp>
+const void*
+__func<_Fp, _Alloc, _Rp()>::target(const type_info& __ti) const
+{
+    if (__ti == typeid(_Fp))
+        return &__f_.first();
+    return (const void*)0;
+}
+
+template<class _Fp, class _Alloc, class _Rp>
+const std::type_info&
+__func<_Fp, _Alloc, _Rp()>::target_type() const
+{
+    return typeid(_Fp);
+}
+
+#endif  // _LIBCPP_NO_RTTI
+
+template<class _Fp, class _Alloc, class _Rp, class _A0>
+class __func<_Fp, _Alloc, _Rp(_A0)>
+    : public  __base<_Rp(_A0)>
+{
+    __compressed_pair<_Fp, _Alloc> __f_;
+public:
+    _LIBCPP_INLINE_VISIBILITY explicit __func(_Fp __f) : __f_(_VSTD::move(__f)) {}
+    _LIBCPP_INLINE_VISIBILITY explicit __func(_Fp __f, _Alloc __a)
+        : __f_(_VSTD::move(__f), _VSTD::move(__a)) {}
+    virtual __base<_Rp(_A0)>* __clone() const;
+    virtual void __clone(__base<_Rp(_A0)>*) const;
+    virtual void destroy();
+    virtual void destroy_deallocate();
+    virtual _Rp operator()(_A0);
+#ifndef _LIBCPP_NO_RTTI
+    virtual const void* target(const type_info&) const;
+    virtual const std::type_info& target_type() const;
+#endif  // _LIBCPP_NO_RTTI
+};
+
+template<class _Fp, class _Alloc, class _Rp, class _A0>
+__base<_Rp(_A0)>*
+__func<_Fp, _Alloc, _Rp(_A0)>::__clone() const
+{
+    typedef allocator_traits<_Alloc> __alloc_traits;
+    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
+    _Ap __a(__f_.second());
+    typedef __allocator_destructor<_Ap> _Dp;
+    unique_ptr<__func, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+    ::new (__hold.get()) __func(__f_.first(), _Alloc(__a));
+    return __hold.release();
+}
+
+template<class _Fp, class _Alloc, class _Rp, class _A0>
+void
+__func<_Fp, _Alloc, _Rp(_A0)>::__clone(__base<_Rp(_A0)>* __p) const
+{
+    ::new (__p) __func(__f_.first(), __f_.second());
+}
+
+template<class _Fp, class _Alloc, class _Rp, class _A0>
+void
+__func<_Fp, _Alloc, _Rp(_A0)>::destroy()
+{
+    __f_.~__compressed_pair<_Fp, _Alloc>();
+}
+
+template<class _Fp, class _Alloc, class _Rp, class _A0>
+void
+__func<_Fp, _Alloc, _Rp(_A0)>::destroy_deallocate()
+{
+    typedef allocator_traits<_Alloc> __alloc_traits;
+    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
+    _Ap __a(__f_.second());
+    __f_.~__compressed_pair<_Fp, _Alloc>();
+    __a.deallocate(this, 1);
+}
+
+template<class _Fp, class _Alloc, class _Rp, class _A0>
+_Rp
+__func<_Fp, _Alloc, _Rp(_A0)>::operator()(_A0 __a0)
+{
+    typedef __invoke_void_return_wrapper<_Rp> _Invoker;
+    return _Invoker::__call(__f_.first(), __a0);
+}
+
+#ifndef _LIBCPP_NO_RTTI
+
+template<class _Fp, class _Alloc, class _Rp, class _A0>
+const void*
+__func<_Fp, _Alloc, _Rp(_A0)>::target(const type_info& __ti) const
+{
+    if (__ti == typeid(_Fp))
+        return &__f_.first();
+    return (const void*)0;
+}
+
+template<class _Fp, class _Alloc, class _Rp, class _A0>
+const std::type_info&
+__func<_Fp, _Alloc, _Rp(_A0)>::target_type() const
+{
+    return typeid(_Fp);
+}
+
+#endif  // _LIBCPP_NO_RTTI
+
+template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1>
+class __func<_Fp, _Alloc, _Rp(_A0, _A1)>
+    : public  __base<_Rp(_A0, _A1)>
+{
+    __compressed_pair<_Fp, _Alloc> __f_;
+public:
+    _LIBCPP_INLINE_VISIBILITY explicit __func(_Fp __f) : __f_(_VSTD::move(__f)) {}
+    _LIBCPP_INLINE_VISIBILITY explicit __func(_Fp __f, _Alloc __a)
+        : __f_(_VSTD::move(__f), _VSTD::move(__a)) {}
+    virtual __base<_Rp(_A0, _A1)>* __clone() const;
+    virtual void __clone(__base<_Rp(_A0, _A1)>*) const;
+    virtual void destroy();
+    virtual void destroy_deallocate();
+    virtual _Rp operator()(_A0, _A1);
+#ifndef _LIBCPP_NO_RTTI
+    virtual const void* target(const type_info&) const;
+    virtual const std::type_info& target_type() const;
+#endif  // _LIBCPP_NO_RTTI
+};
+
+template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1>
+__base<_Rp(_A0, _A1)>*
+__func<_Fp, _Alloc, _Rp(_A0, _A1)>::__clone() const
+{
+    typedef allocator_traits<_Alloc> __alloc_traits;
+    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
+    _Ap __a(__f_.second());
+    typedef __allocator_destructor<_Ap> _Dp;
+    unique_ptr<__func, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+    ::new (__hold.get()) __func(__f_.first(), _Alloc(__a));
+    return __hold.release();
+}
+
+template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1>
+void
+__func<_Fp, _Alloc, _Rp(_A0, _A1)>::__clone(__base<_Rp(_A0, _A1)>* __p) const
+{
+    ::new (__p) __func(__f_.first(), __f_.second());
+}
+
+template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1>
+void
+__func<_Fp, _Alloc, _Rp(_A0, _A1)>::destroy()
+{
+    __f_.~__compressed_pair<_Fp, _Alloc>();
+}
+
+template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1>
+void
+__func<_Fp, _Alloc, _Rp(_A0, _A1)>::destroy_deallocate()
+{
+    typedef allocator_traits<_Alloc> __alloc_traits;
+    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
+    _Ap __a(__f_.second());
+    __f_.~__compressed_pair<_Fp, _Alloc>();
+    __a.deallocate(this, 1);
+}
+
+template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1>
+_Rp
+__func<_Fp, _Alloc, _Rp(_A0, _A1)>::operator()(_A0 __a0, _A1 __a1)
+{
+    typedef __invoke_void_return_wrapper<_Rp> _Invoker;
+    return _Invoker::__call(__f_.first(), __a0, __a1);
+}
+
+#ifndef _LIBCPP_NO_RTTI
+
+template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1>
+const void*
+__func<_Fp, _Alloc, _Rp(_A0, _A1)>::target(const type_info& __ti) const
+{
+    if (__ti == typeid(_Fp))
+        return &__f_.first();
+    return (const void*)0;
+}
+
+template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1>
+const std::type_info&
+__func<_Fp, _Alloc, _Rp(_A0, _A1)>::target_type() const
+{
+    return typeid(_Fp);
+}
+
+#endif  // _LIBCPP_NO_RTTI
+
+template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1, class _A2>
+class __func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)>
+    : public  __base<_Rp(_A0, _A1, _A2)>
+{
+    __compressed_pair<_Fp, _Alloc> __f_;
+public:
+    _LIBCPP_INLINE_VISIBILITY explicit __func(_Fp __f) : __f_(_VSTD::move(__f)) {}
+    _LIBCPP_INLINE_VISIBILITY explicit __func(_Fp __f, _Alloc __a)
+        : __f_(_VSTD::move(__f), _VSTD::move(__a)) {}
+    virtual __base<_Rp(_A0, _A1, _A2)>* __clone() const;
+    virtual void __clone(__base<_Rp(_A0, _A1, _A2)>*) const;
+    virtual void destroy();
+    virtual void destroy_deallocate();
+    virtual _Rp operator()(_A0, _A1, _A2);
+#ifndef _LIBCPP_NO_RTTI
+    virtual const void* target(const type_info&) const;
+    virtual const std::type_info& target_type() const;
+#endif  // _LIBCPP_NO_RTTI
+};
+
+template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1, class _A2>
+__base<_Rp(_A0, _A1, _A2)>*
+__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)>::__clone() const
+{
+    typedef allocator_traits<_Alloc> __alloc_traits;
+    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
+    _Ap __a(__f_.second());
+    typedef __allocator_destructor<_Ap> _Dp;
+    unique_ptr<__func, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+    ::new (__hold.get()) __func(__f_.first(), _Alloc(__a));
+    return __hold.release();
+}
+
+template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1, class _A2>
+void
+__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)>::__clone(__base<_Rp(_A0, _A1, _A2)>* __p) const
+{
+    ::new (__p) __func(__f_.first(), __f_.second());
+}
+
+template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1, class _A2>
+void
+__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)>::destroy()
+{
+    __f_.~__compressed_pair<_Fp, _Alloc>();
+}
+
+template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1, class _A2>
+void
+__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)>::destroy_deallocate()
+{
+    typedef allocator_traits<_Alloc> __alloc_traits;
+    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
+    _Ap __a(__f_.second());
+    __f_.~__compressed_pair<_Fp, _Alloc>();
+    __a.deallocate(this, 1);
+}
+
+template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1, class _A2>
+_Rp
+__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)>::operator()(_A0 __a0, _A1 __a1, _A2 __a2)
+{
+    typedef __invoke_void_return_wrapper<_Rp> _Invoker;
+    return _Invoker::__call(__f_.first(), __a0, __a1, __a2);
+}
+
+#ifndef _LIBCPP_NO_RTTI
+
+template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1, class _A2>
+const void*
+__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)>::target(const type_info& __ti) const
+{
+    if (__ti == typeid(_Fp))
+        return &__f_.first();
+    return (const void*)0;
+}
+
+template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1, class _A2>
+const std::type_info&
+__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)>::target_type() const
+{
+    return typeid(_Fp);
+}
+
+#endif  // _LIBCPP_NO_RTTI
+
+}  // __function
+
+template<class _Rp>
+class _LIBCPP_TYPE_VIS_ONLY function<_Rp()>
+{
+    typedef __function::__base<_Rp()> __base;
+    aligned_storage<3*sizeof(void*)>::type __buf_;
+    __base* __f_;
+
+    template <class _Fp>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(const _Fp&) {return true;}
+    template <class _R2>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (*__p)()) {return __p;}
+    template <class _R2>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(const function<_R2()>& __p) {return __p;}
+public:
+    typedef _Rp result_type;
+
+    // 20.7.16.2.1, construct/copy/destroy:
+    _LIBCPP_INLINE_VISIBILITY explicit function() : __f_(0) {}
+    _LIBCPP_INLINE_VISIBILITY function(nullptr_t) : __f_(0) {}
+    function(const function&);
+    template<class _Fp>
+      function(_Fp,
+               typename enable_if<!is_integral<_Fp>::value>::type* = 0);
+
+    template<class _Alloc>
+      _LIBCPP_INLINE_VISIBILITY
+      function(allocator_arg_t, const _Alloc&) : __f_(0) {}
+    template<class _Alloc>
+      _LIBCPP_INLINE_VISIBILITY
+      function(allocator_arg_t, const _Alloc&, nullptr_t) : __f_(0) {}
+    template<class _Alloc>
+      function(allocator_arg_t, const _Alloc&, const function&);
+    template<class _Fp, class _Alloc>
+      function(allocator_arg_t, const _Alloc& __a, _Fp __f,
+               typename enable_if<!is_integral<_Fp>::value>::type* = 0);
+
+    function& operator=(const function&);
+    function& operator=(nullptr_t);
+    template<class _Fp>
+      typename enable_if
+      <
+        !is_integral<_Fp>::value,
+        function&
+      >::type
+      operator=(_Fp);
+
+    ~function();
+
+    // 20.7.16.2.2, function modifiers:
+    void swap(function&);
+    template<class _Fp, class _Alloc>
+      _LIBCPP_INLINE_VISIBILITY
+      void assign(_Fp __f, const _Alloc& __a)
+        {function(allocator_arg, __a, __f).swap(*this);}
+
+    // 20.7.16.2.3, function capacity:
+    _LIBCPP_INLINE_VISIBILITY operator bool() const {return __f_;}
+
+private:
+    // deleted overloads close possible hole in the type system
+    template<class _R2>
+      bool operator==(const function<_R2()>&) const;// = delete;
+    template<class _R2>
+      bool operator!=(const function<_R2()>&) const;// = delete;
+public:
+    // 20.7.16.2.4, function invocation:
+    _Rp operator()() const;
+
+#ifndef _LIBCPP_NO_RTTI
+    // 20.7.16.2.5, function target access:
+    const std::type_info& target_type() const;
+    template <typename _Tp> _Tp* target();
+    template <typename _Tp> const _Tp* target() const;
+#endif  // _LIBCPP_NO_RTTI
+};
+
+template<class _Rp>
+function<_Rp()>::function(const function& __f)
+{
+    if (__f.__f_ == 0)
+        __f_ = 0;
+    else if (__f.__f_ == (const __base*)&__f.__buf_)
+    {
+        __f_ = (__base*)&__buf_;
+        __f.__f_->__clone(__f_);
+    }
+    else
+        __f_ = __f.__f_->__clone();
+}
+
+template<class _Rp>
+template<class _Alloc>
+function<_Rp()>::function(allocator_arg_t, const _Alloc&, const function& __f)
+{
+    if (__f.__f_ == 0)
+        __f_ = 0;
+    else if (__f.__f_ == (const __base*)&__f.__buf_)
+    {
+        __f_ = (__base*)&__buf_;
+        __f.__f_->__clone(__f_);
+    }
+    else
+        __f_ = __f.__f_->__clone();
+}
+
+template<class _Rp>
+template <class _Fp>
+function<_Rp()>::function(_Fp __f,
+                                     typename enable_if<!is_integral<_Fp>::value>::type*)
+    : __f_(0)
+{
+    if (__not_null(__f))
+    {
+        typedef __function::__func<_Fp, allocator<_Fp>, _Rp()> _FF;
+        if (sizeof(_FF) <= sizeof(__buf_))
+        {
+            __f_ = (__base*)&__buf_;
+            ::new (__f_) _FF(__f);
+        }
+        else
+        {
+            typedef allocator<_FF> _Ap;
+            _Ap __a;
+            typedef __allocator_destructor<_Ap> _Dp;
+            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+            ::new (__hold.get()) _FF(__f, allocator<_Fp>(__a));
+            __f_ = __hold.release();
+        }
+    }
+}
+
+template<class _Rp>
+template <class _Fp, class _Alloc>
+function<_Rp()>::function(allocator_arg_t, const _Alloc& __a0, _Fp __f,
+                                     typename enable_if<!is_integral<_Fp>::value>::type*)
+    : __f_(0)
+{
+    typedef allocator_traits<_Alloc> __alloc_traits;
+    if (__not_null(__f))
+    {
+        typedef __function::__func<_Fp, _Alloc, _Rp()> _FF;
+        if (sizeof(_FF) <= sizeof(__buf_))
+        {
+            __f_ = (__base*)&__buf_;
+            ::new (__f_) _FF(__f, __a0);
+        }
+        else
+        {
+            typedef typename __rebind_alloc_helper<__alloc_traits, _FF>::type _Ap;
+            _Ap __a(__a0);
+            typedef __allocator_destructor<_Ap> _Dp;
+            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+            ::new (__hold.get()) _FF(__f, _Alloc(__a));
+            __f_ = __hold.release();
+        }
+    }
+}
+
+template<class _Rp>
+function<_Rp()>&
+function<_Rp()>::operator=(const function& __f)
+{
+    function(__f).swap(*this);
+    return *this;
+}
+
+template<class _Rp>
+function<_Rp()>&
+function<_Rp()>::operator=(nullptr_t)
+{
+    if (__f_ == (__base*)&__buf_)
+        __f_->destroy();
+    else if (__f_)
+        __f_->destroy_deallocate();
+    __f_ = 0;
+    return *this;
+}
+
+template<class _Rp>
+template <class _Fp>
+typename enable_if
+<
+    !is_integral<_Fp>::value,
+    function<_Rp()>&
+>::type
+function<_Rp()>::operator=(_Fp __f)
+{
+    function(_VSTD::move(__f)).swap(*this);
+    return *this;
+}
+
+template<class _Rp>
+function<_Rp()>::~function()
+{
+    if (__f_ == (__base*)&__buf_)
+        __f_->destroy();
+    else if (__f_)
+        __f_->destroy_deallocate();
+}
+
+template<class _Rp>
+void
+function<_Rp()>::swap(function& __f)
+{
+    if (__f_ == (__base*)&__buf_ && __f.__f_ == (__base*)&__f.__buf_)
+    {
+        typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
+        __base* __t = (__base*)&__tempbuf;
+        __f_->__clone(__t);
+        __f_->destroy();
+        __f_ = 0;
+        __f.__f_->__clone((__base*)&__buf_);
+        __f.__f_->destroy();
+        __f.__f_ = 0;
+        __f_ = (__base*)&__buf_;
+        __t->__clone((__base*)&__f.__buf_);
+        __t->destroy();
+        __f.__f_ = (__base*)&__f.__buf_;
+    }
+    else if (__f_ == (__base*)&__buf_)
+    {
+        __f_->__clone((__base*)&__f.__buf_);
+        __f_->destroy();
+        __f_ = __f.__f_;
+        __f.__f_ = (__base*)&__f.__buf_;
+    }
+    else if (__f.__f_ == (__base*)&__f.__buf_)
+    {
+        __f.__f_->__clone((__base*)&__buf_);
+        __f.__f_->destroy();
+        __f.__f_ = __f_;
+        __f_ = (__base*)&__buf_;
+    }
+    else
+        _VSTD::swap(__f_, __f.__f_);
+}
+
+template<class _Rp>
+_Rp
+function<_Rp()>::operator()() const
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__f_ == 0)
+        throw bad_function_call();
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return (*__f_)();
+}
+
+#ifndef _LIBCPP_NO_RTTI
+
+template<class _Rp>
+const std::type_info&
+function<_Rp()>::target_type() const
+{
+    if (__f_ == 0)
+        return typeid(void);
+    return __f_->target_type();
+}
+
+template<class _Rp>
+template <typename _Tp>
+_Tp*
+function<_Rp()>::target()
+{
+    if (__f_ == 0)
+        return (_Tp*)0;
+    return (_Tp*)__f_->target(typeid(_Tp));
+}
+
+template<class _Rp>
+template <typename _Tp>
+const _Tp*
+function<_Rp()>::target() const
+{
+    if (__f_ == 0)
+        return (const _Tp*)0;
+    return (const _Tp*)__f_->target(typeid(_Tp));
+}
+
+#endif  // _LIBCPP_NO_RTTI
+
+template<class _Rp, class _A0>
+class _LIBCPP_TYPE_VIS_ONLY function<_Rp(_A0)>
+    : public unary_function<_A0, _Rp>
+{
+    typedef __function::__base<_Rp(_A0)> __base;
+    aligned_storage<3*sizeof(void*)>::type __buf_;
+    __base* __f_;
+
+    template <class _Fp>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(const _Fp&) {return true;}
+    template <class _R2, class _B0>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (*__p)(_B0)) {return __p;}
+    template <class _R2, class _Cp>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (_Cp::*__p)()) {return __p;}
+    template <class _R2, class _Cp>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (_Cp::*__p)() const) {return __p;}
+    template <class _R2, class _Cp>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (_Cp::*__p)() volatile) {return __p;}
+    template <class _R2, class _Cp>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (_Cp::*__p)() const volatile) {return __p;}
+    template <class _R2, class _B0>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(const function<_R2(_B0)>& __p) {return __p;}
+public:
+    typedef _Rp result_type;
+
+    // 20.7.16.2.1, construct/copy/destroy:
+    _LIBCPP_INLINE_VISIBILITY explicit function() : __f_(0) {}
+    _LIBCPP_INLINE_VISIBILITY function(nullptr_t) : __f_(0) {}
+    function(const function&);
+    template<class _Fp>
+      function(_Fp,
+               typename enable_if<!is_integral<_Fp>::value>::type* = 0);
+
+    template<class _Alloc>
+      _LIBCPP_INLINE_VISIBILITY
+      function(allocator_arg_t, const _Alloc&) : __f_(0) {}
+    template<class _Alloc>
+      _LIBCPP_INLINE_VISIBILITY
+      function(allocator_arg_t, const _Alloc&, nullptr_t) : __f_(0) {}
+    template<class _Alloc>
+      function(allocator_arg_t, const _Alloc&, const function&);
+    template<class _Fp, class _Alloc>
+      function(allocator_arg_t, const _Alloc& __a, _Fp __f,
+               typename enable_if<!is_integral<_Fp>::value>::type* = 0);
+
+    function& operator=(const function&);
+    function& operator=(nullptr_t);
+    template<class _Fp>
+      typename enable_if
+      <
+        !is_integral<_Fp>::value,
+        function&
+      >::type
+      operator=(_Fp);
+
+    ~function();
+
+    // 20.7.16.2.2, function modifiers:
+    void swap(function&);
+    template<class _Fp, class _Alloc>
+      _LIBCPP_INLINE_VISIBILITY
+      void assign(_Fp __f, const _Alloc& __a)
+        {function(allocator_arg, __a, __f).swap(*this);}
+
+    // 20.7.16.2.3, function capacity:
+    _LIBCPP_INLINE_VISIBILITY operator bool() const {return __f_;}
+
+private:
+    // deleted overloads close possible hole in the type system
+    template<class _R2, class _B0>
+      bool operator==(const function<_R2(_B0)>&) const;// = delete;
+    template<class _R2, class _B0>
+      bool operator!=(const function<_R2(_B0)>&) const;// = delete;
+public:
+    // 20.7.16.2.4, function invocation:
+    _Rp operator()(_A0) const;
+
+#ifndef _LIBCPP_NO_RTTI
+    // 20.7.16.2.5, function target access:
+    const std::type_info& target_type() const;
+    template <typename _Tp> _Tp* target();
+    template <typename _Tp> const _Tp* target() const;
+#endif  // _LIBCPP_NO_RTTI
+};
+
+template<class _Rp, class _A0>
+function<_Rp(_A0)>::function(const function& __f)
+{
+    if (__f.__f_ == 0)
+        __f_ = 0;
+    else if (__f.__f_ == (const __base*)&__f.__buf_)
+    {
+        __f_ = (__base*)&__buf_;
+        __f.__f_->__clone(__f_);
+    }
+    else
+        __f_ = __f.__f_->__clone();
+}
+
+template<class _Rp, class _A0>
+template<class _Alloc>
+function<_Rp(_A0)>::function(allocator_arg_t, const _Alloc&, const function& __f)
+{
+    if (__f.__f_ == 0)
+        __f_ = 0;
+    else if (__f.__f_ == (const __base*)&__f.__buf_)
+    {
+        __f_ = (__base*)&__buf_;
+        __f.__f_->__clone(__f_);
+    }
+    else
+        __f_ = __f.__f_->__clone();
+}
+
+template<class _Rp, class _A0>
+template <class _Fp>
+function<_Rp(_A0)>::function(_Fp __f,
+                                     typename enable_if<!is_integral<_Fp>::value>::type*)
+    : __f_(0)
+{
+    if (__not_null(__f))
+    {
+        typedef __function::__func<_Fp, allocator<_Fp>, _Rp(_A0)> _FF;
+        if (sizeof(_FF) <= sizeof(__buf_))
+        {
+            __f_ = (__base*)&__buf_;
+            ::new (__f_) _FF(__f);
+        }
+        else
+        {
+            typedef allocator<_FF> _Ap;
+            _Ap __a;
+            typedef __allocator_destructor<_Ap> _Dp;
+            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+            ::new (__hold.get()) _FF(__f, allocator<_Fp>(__a));
+            __f_ = __hold.release();
+        }
+    }
+}
+
+template<class _Rp, class _A0>
+template <class _Fp, class _Alloc>
+function<_Rp(_A0)>::function(allocator_arg_t, const _Alloc& __a0, _Fp __f,
+                                     typename enable_if<!is_integral<_Fp>::value>::type*)
+    : __f_(0)
+{
+    typedef allocator_traits<_Alloc> __alloc_traits;
+    if (__not_null(__f))
+    {
+        typedef __function::__func<_Fp, _Alloc, _Rp(_A0)> _FF;
+        if (sizeof(_FF) <= sizeof(__buf_))
+        {
+            __f_ = (__base*)&__buf_;
+            ::new (__f_) _FF(__f, __a0);
+        }
+        else
+        {
+            typedef typename __rebind_alloc_helper<__alloc_traits, _FF>::type _Ap;
+            _Ap __a(__a0);
+            typedef __allocator_destructor<_Ap> _Dp;
+            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+            ::new (__hold.get()) _FF(__f, _Alloc(__a));
+            __f_ = __hold.release();
+        }
+    }
+}
+
+template<class _Rp, class _A0>
+function<_Rp(_A0)>&
+function<_Rp(_A0)>::operator=(const function& __f)
+{
+    function(__f).swap(*this);
+    return *this;
+}
+
+template<class _Rp, class _A0>
+function<_Rp(_A0)>&
+function<_Rp(_A0)>::operator=(nullptr_t)
+{
+    if (__f_ == (__base*)&__buf_)
+        __f_->destroy();
+    else if (__f_)
+        __f_->destroy_deallocate();
+    __f_ = 0;
+    return *this;
+}
+
+template<class _Rp, class _A0>
+template <class _Fp>
+typename enable_if
+<
+    !is_integral<_Fp>::value,
+    function<_Rp(_A0)>&
+>::type
+function<_Rp(_A0)>::operator=(_Fp __f)
+{
+    function(_VSTD::move(__f)).swap(*this);
+    return *this;
+}
+
+template<class _Rp, class _A0>
+function<_Rp(_A0)>::~function()
+{
+    if (__f_ == (__base*)&__buf_)
+        __f_->destroy();
+    else if (__f_)
+        __f_->destroy_deallocate();
+}
+
+template<class _Rp, class _A0>
+void
+function<_Rp(_A0)>::swap(function& __f)
+{
+    if (__f_ == (__base*)&__buf_ && __f.__f_ == (__base*)&__f.__buf_)
+    {
+        typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
+        __base* __t = (__base*)&__tempbuf;
+        __f_->__clone(__t);
+        __f_->destroy();
+        __f_ = 0;
+        __f.__f_->__clone((__base*)&__buf_);
+        __f.__f_->destroy();
+        __f.__f_ = 0;
+        __f_ = (__base*)&__buf_;
+        __t->__clone((__base*)&__f.__buf_);
+        __t->destroy();
+        __f.__f_ = (__base*)&__f.__buf_;
+    }
+    else if (__f_ == (__base*)&__buf_)
+    {
+        __f_->__clone((__base*)&__f.__buf_);
+        __f_->destroy();
+        __f_ = __f.__f_;
+        __f.__f_ = (__base*)&__f.__buf_;
+    }
+    else if (__f.__f_ == (__base*)&__f.__buf_)
+    {
+        __f.__f_->__clone((__base*)&__buf_);
+        __f.__f_->destroy();
+        __f.__f_ = __f_;
+        __f_ = (__base*)&__buf_;
+    }
+    else
+        _VSTD::swap(__f_, __f.__f_);
+}
+
+template<class _Rp, class _A0>
+_Rp
+function<_Rp(_A0)>::operator()(_A0 __a0) const
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__f_ == 0)
+        throw bad_function_call();
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return (*__f_)(__a0);
+}
+
+#ifndef _LIBCPP_NO_RTTI
+
+template<class _Rp, class _A0>
+const std::type_info&
+function<_Rp(_A0)>::target_type() const
+{
+    if (__f_ == 0)
+        return typeid(void);
+    return __f_->target_type();
+}
+
+template<class _Rp, class _A0>
+template <typename _Tp>
+_Tp*
+function<_Rp(_A0)>::target()
+{
+    if (__f_ == 0)
+        return (_Tp*)0;
+    return (_Tp*)__f_->target(typeid(_Tp));
+}
+
+template<class _Rp, class _A0>
+template <typename _Tp>
+const _Tp*
+function<_Rp(_A0)>::target() const
+{
+    if (__f_ == 0)
+        return (const _Tp*)0;
+    return (const _Tp*)__f_->target(typeid(_Tp));
+}
+
+#endif  // _LIBCPP_NO_RTTI
+
+template<class _Rp, class _A0, class _A1>
+class _LIBCPP_TYPE_VIS_ONLY function<_Rp(_A0, _A1)>
+    : public binary_function<_A0, _A1, _Rp>
+{
+    typedef __function::__base<_Rp(_A0, _A1)> __base;
+    aligned_storage<3*sizeof(void*)>::type __buf_;
+    __base* __f_;
+
+    template <class _Fp>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(const _Fp&) {return true;}
+    template <class _R2, class _B0, class _B1>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (*__p)(_B0, _B1)) {return __p;}
+    template <class _R2, class _Cp, class _B1>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (_Cp::*__p)(_B1)) {return __p;}
+    template <class _R2, class _Cp, class _B1>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (_Cp::*__p)(_B1) const) {return __p;}
+    template <class _R2, class _Cp, class _B1>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (_Cp::*__p)(_B1) volatile) {return __p;}
+    template <class _R2, class _Cp, class _B1>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (_Cp::*__p)(_B1) const volatile) {return __p;}
+    template <class _R2, class _B0, class _B1>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(const function<_R2(_B0, _B1)>& __p) {return __p;}
+public:
+    typedef _Rp result_type;
+
+    // 20.7.16.2.1, construct/copy/destroy:
+    _LIBCPP_INLINE_VISIBILITY explicit function() : __f_(0) {}
+    _LIBCPP_INLINE_VISIBILITY function(nullptr_t) : __f_(0) {}
+    function(const function&);
+    template<class _Fp>
+      function(_Fp,
+               typename enable_if<!is_integral<_Fp>::value>::type* = 0);
+
+    template<class _Alloc>
+      _LIBCPP_INLINE_VISIBILITY
+      function(allocator_arg_t, const _Alloc&) : __f_(0) {}
+    template<class _Alloc>
+      _LIBCPP_INLINE_VISIBILITY
+      function(allocator_arg_t, const _Alloc&, nullptr_t) : __f_(0) {}
+    template<class _Alloc>
+      function(allocator_arg_t, const _Alloc&, const function&);
+    template<class _Fp, class _Alloc>
+      function(allocator_arg_t, const _Alloc& __a, _Fp __f,
+               typename enable_if<!is_integral<_Fp>::value>::type* = 0);
+
+    function& operator=(const function&);
+    function& operator=(nullptr_t);
+    template<class _Fp>
+      typename enable_if
+      <
+        !is_integral<_Fp>::value,
+        function&
+      >::type
+      operator=(_Fp);
+
+    ~function();
+
+    // 20.7.16.2.2, function modifiers:
+    void swap(function&);
+    template<class _Fp, class _Alloc>
+      _LIBCPP_INLINE_VISIBILITY
+      void assign(_Fp __f, const _Alloc& __a)
+        {function(allocator_arg, __a, __f).swap(*this);}
+
+    // 20.7.16.2.3, function capacity:
+    operator bool() const {return __f_;}
+
+private:
+    // deleted overloads close possible hole in the type system
+    template<class _R2, class _B0, class _B1>
+      bool operator==(const function<_R2(_B0, _B1)>&) const;// = delete;
+    template<class _R2, class _B0, class _B1>
+      bool operator!=(const function<_R2(_B0, _B1)>&) const;// = delete;
+public:
+    // 20.7.16.2.4, function invocation:
+    _Rp operator()(_A0, _A1) const;
+
+#ifndef _LIBCPP_NO_RTTI
+    // 20.7.16.2.5, function target access:
+    const std::type_info& target_type() const;
+    template <typename _Tp> _Tp* target();
+    template <typename _Tp> const _Tp* target() const;
+#endif  // _LIBCPP_NO_RTTI
+};
+
+template<class _Rp, class _A0, class _A1>
+function<_Rp(_A0, _A1)>::function(const function& __f)
+{
+    if (__f.__f_ == 0)
+        __f_ = 0;
+    else if (__f.__f_ == (const __base*)&__f.__buf_)
+    {
+        __f_ = (__base*)&__buf_;
+        __f.__f_->__clone(__f_);
+    }
+    else
+        __f_ = __f.__f_->__clone();
+}
+
+template<class _Rp, class _A0, class _A1>
+template<class _Alloc>
+function<_Rp(_A0, _A1)>::function(allocator_arg_t, const _Alloc&, const function& __f)
+{
+    if (__f.__f_ == 0)
+        __f_ = 0;
+    else if (__f.__f_ == (const __base*)&__f.__buf_)
+    {
+        __f_ = (__base*)&__buf_;
+        __f.__f_->__clone(__f_);
+    }
+    else
+        __f_ = __f.__f_->__clone();
+}
+
+template<class _Rp, class _A0, class _A1>
+template <class _Fp>
+function<_Rp(_A0, _A1)>::function(_Fp __f,
+                                 typename enable_if<!is_integral<_Fp>::value>::type*)
+    : __f_(0)
+{
+    if (__not_null(__f))
+    {
+        typedef __function::__func<_Fp, allocator<_Fp>, _Rp(_A0, _A1)> _FF;
+        if (sizeof(_FF) <= sizeof(__buf_))
+        {
+            __f_ = (__base*)&__buf_;
+            ::new (__f_) _FF(__f);
+        }
+        else
+        {
+            typedef allocator<_FF> _Ap;
+            _Ap __a;
+            typedef __allocator_destructor<_Ap> _Dp;
+            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+            ::new (__hold.get()) _FF(__f, allocator<_Fp>(__a));
+            __f_ = __hold.release();
+        }
+    }
+}
+
+template<class _Rp, class _A0, class _A1>
+template <class _Fp, class _Alloc>
+function<_Rp(_A0, _A1)>::function(allocator_arg_t, const _Alloc& __a0, _Fp __f,
+                                 typename enable_if<!is_integral<_Fp>::value>::type*)
+    : __f_(0)
+{
+    typedef allocator_traits<_Alloc> __alloc_traits;
+    if (__not_null(__f))
+    {
+        typedef __function::__func<_Fp, _Alloc, _Rp(_A0, _A1)> _FF;
+        if (sizeof(_FF) <= sizeof(__buf_))
+        {
+            __f_ = (__base*)&__buf_;
+            ::new (__f_) _FF(__f, __a0);
+        }
+        else
+        {
+            typedef typename __rebind_alloc_helper<__alloc_traits, _FF>::type _Ap;
+            _Ap __a(__a0);
+            typedef __allocator_destructor<_Ap> _Dp;
+            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+            ::new (__hold.get()) _FF(__f, _Alloc(__a));
+            __f_ = __hold.release();
+        }
+    }
+}
+
+template<class _Rp, class _A0, class _A1>
+function<_Rp(_A0, _A1)>&
+function<_Rp(_A0, _A1)>::operator=(const function& __f)
+{
+    function(__f).swap(*this);
+    return *this;
+}
+
+template<class _Rp, class _A0, class _A1>
+function<_Rp(_A0, _A1)>&
+function<_Rp(_A0, _A1)>::operator=(nullptr_t)
+{
+    if (__f_ == (__base*)&__buf_)
+        __f_->destroy();
+    else if (__f_)
+        __f_->destroy_deallocate();
+    __f_ = 0;
+    return *this;
+}
+
+template<class _Rp, class _A0, class _A1>
+template <class _Fp>
+typename enable_if
+<
+    !is_integral<_Fp>::value,
+    function<_Rp(_A0, _A1)>&
+>::type
+function<_Rp(_A0, _A1)>::operator=(_Fp __f)
+{
+    function(_VSTD::move(__f)).swap(*this);
+    return *this;
+}
+
+template<class _Rp, class _A0, class _A1>
+function<_Rp(_A0, _A1)>::~function()
+{
+    if (__f_ == (__base*)&__buf_)
+        __f_->destroy();
+    else if (__f_)
+        __f_->destroy_deallocate();
+}
+
+template<class _Rp, class _A0, class _A1>
+void
+function<_Rp(_A0, _A1)>::swap(function& __f)
+{
+    if (__f_ == (__base*)&__buf_ && __f.__f_ == (__base*)&__f.__buf_)
+    {
+        typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
+        __base* __t = (__base*)&__tempbuf;
+        __f_->__clone(__t);
+        __f_->destroy();
+        __f_ = 0;
+        __f.__f_->__clone((__base*)&__buf_);
+        __f.__f_->destroy();
+        __f.__f_ = 0;
+        __f_ = (__base*)&__buf_;
+        __t->__clone((__base*)&__f.__buf_);
+        __t->destroy();
+        __f.__f_ = (__base*)&__f.__buf_;
+    }
+    else if (__f_ == (__base*)&__buf_)
+    {
+        __f_->__clone((__base*)&__f.__buf_);
+        __f_->destroy();
+        __f_ = __f.__f_;
+        __f.__f_ = (__base*)&__f.__buf_;
+    }
+    else if (__f.__f_ == (__base*)&__f.__buf_)
+    {
+        __f.__f_->__clone((__base*)&__buf_);
+        __f.__f_->destroy();
+        __f.__f_ = __f_;
+        __f_ = (__base*)&__buf_;
+    }
+    else
+        _VSTD::swap(__f_, __f.__f_);
+}
+
+template<class _Rp, class _A0, class _A1>
+_Rp
+function<_Rp(_A0, _A1)>::operator()(_A0 __a0, _A1 __a1) const
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__f_ == 0)
+        throw bad_function_call();
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return (*__f_)(__a0, __a1);
+}
+
+#ifndef _LIBCPP_NO_RTTI
+
+template<class _Rp, class _A0, class _A1>
+const std::type_info&
+function<_Rp(_A0, _A1)>::target_type() const
+{
+    if (__f_ == 0)
+        return typeid(void);
+    return __f_->target_type();
+}
+
+template<class _Rp, class _A0, class _A1>
+template <typename _Tp>
+_Tp*
+function<_Rp(_A0, _A1)>::target()
+{
+    if (__f_ == 0)
+        return (_Tp*)0;
+    return (_Tp*)__f_->target(typeid(_Tp));
+}
+
+template<class _Rp, class _A0, class _A1>
+template <typename _Tp>
+const _Tp*
+function<_Rp(_A0, _A1)>::target() const
+{
+    if (__f_ == 0)
+        return (const _Tp*)0;
+    return (const _Tp*)__f_->target(typeid(_Tp));
+}
+
+#endif  // _LIBCPP_NO_RTTI
+
+template<class _Rp, class _A0, class _A1, class _A2>
+class _LIBCPP_TYPE_VIS_ONLY function<_Rp(_A0, _A1, _A2)>
+{
+    typedef __function::__base<_Rp(_A0, _A1, _A2)> __base;
+    aligned_storage<3*sizeof(void*)>::type __buf_;
+    __base* __f_;
+
+    template <class _Fp>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(const _Fp&) {return true;}
+    template <class _R2, class _B0, class _B1, class _B2>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (*__p)(_B0, _B1, _B2)) {return __p;}
+    template <class _R2, class _Cp, class _B1, class _B2>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (_Cp::*__p)(_B1, _B2)) {return __p;}
+    template <class _R2, class _Cp, class _B1, class _B2>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (_Cp::*__p)(_B1, _B2) const) {return __p;}
+    template <class _R2, class _Cp, class _B1, class _B2>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (_Cp::*__p)(_B1, _B2) volatile) {return __p;}
+    template <class _R2, class _Cp, class _B1, class _B2>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (_Cp::*__p)(_B1, _B2) const volatile) {return __p;}
+    template <class _R2, class _B0, class _B1, class _B2>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(const function<_R2(_B0, _B1, _B2)>& __p) {return __p;}
+public:
+    typedef _Rp result_type;
+
+    // 20.7.16.2.1, construct/copy/destroy:
+    _LIBCPP_INLINE_VISIBILITY explicit function() : __f_(0) {}
+    _LIBCPP_INLINE_VISIBILITY function(nullptr_t) : __f_(0) {}
+    function(const function&);
+    template<class _Fp>
+      function(_Fp,
+               typename enable_if<!is_integral<_Fp>::value>::type* = 0);
+
+    template<class _Alloc>
+      _LIBCPP_INLINE_VISIBILITY
+      function(allocator_arg_t, const _Alloc&) : __f_(0) {}
+    template<class _Alloc>
+      _LIBCPP_INLINE_VISIBILITY
+      function(allocator_arg_t, const _Alloc&, nullptr_t) : __f_(0) {}
+    template<class _Alloc>
+      function(allocator_arg_t, const _Alloc&, const function&);
+    template<class _Fp, class _Alloc>
+      function(allocator_arg_t, const _Alloc& __a, _Fp __f,
+               typename enable_if<!is_integral<_Fp>::value>::type* = 0);
+
+    function& operator=(const function&);
+    function& operator=(nullptr_t);
+    template<class _Fp>
+      typename enable_if
+      <
+        !is_integral<_Fp>::value,
+        function&
+      >::type
+      operator=(_Fp);
+
+    ~function();
+
+    // 20.7.16.2.2, function modifiers:
+    void swap(function&);
+    template<class _Fp, class _Alloc>
+      _LIBCPP_INLINE_VISIBILITY
+      void assign(_Fp __f, const _Alloc& __a)
+        {function(allocator_arg, __a, __f).swap(*this);}
+
+    // 20.7.16.2.3, function capacity:
+    _LIBCPP_INLINE_VISIBILITY operator bool() const {return __f_;}
+
+private:
+    // deleted overloads close possible hole in the type system
+    template<class _R2, class _B0, class _B1, class _B2>
+      bool operator==(const function<_R2(_B0, _B1, _B2)>&) const;// = delete;
+    template<class _R2, class _B0, class _B1, class _B2>
+      bool operator!=(const function<_R2(_B0, _B1, _B2)>&) const;// = delete;
+public:
+    // 20.7.16.2.4, function invocation:
+    _Rp operator()(_A0, _A1, _A2) const;
+
+#ifndef _LIBCPP_NO_RTTI
+    // 20.7.16.2.5, function target access:
+    const std::type_info& target_type() const;
+    template <typename _Tp> _Tp* target();
+    template <typename _Tp> const _Tp* target() const;
+#endif  // _LIBCPP_NO_RTTI
+};
+
+template<class _Rp, class _A0, class _A1, class _A2>
+function<_Rp(_A0, _A1, _A2)>::function(const function& __f)
+{
+    if (__f.__f_ == 0)
+        __f_ = 0;
+    else if (__f.__f_ == (const __base*)&__f.__buf_)
+    {
+        __f_ = (__base*)&__buf_;
+        __f.__f_->__clone(__f_);
+    }
+    else
+        __f_ = __f.__f_->__clone();
+}
+
+template<class _Rp, class _A0, class _A1, class _A2>
+template<class _Alloc>
+function<_Rp(_A0, _A1, _A2)>::function(allocator_arg_t, const _Alloc&,
+                                      const function& __f)
+{
+    if (__f.__f_ == 0)
+        __f_ = 0;
+    else if (__f.__f_ == (const __base*)&__f.__buf_)
+    {
+        __f_ = (__base*)&__buf_;
+        __f.__f_->__clone(__f_);
+    }
+    else
+        __f_ = __f.__f_->__clone();
+}
+
+template<class _Rp, class _A0, class _A1, class _A2>
+template <class _Fp>
+function<_Rp(_A0, _A1, _A2)>::function(_Fp __f,
+                                     typename enable_if<!is_integral<_Fp>::value>::type*)
+    : __f_(0)
+{
+    if (__not_null(__f))
+    {
+        typedef __function::__func<_Fp, allocator<_Fp>, _Rp(_A0, _A1, _A2)> _FF;
+        if (sizeof(_FF) <= sizeof(__buf_))
+        {
+            __f_ = (__base*)&__buf_;
+            ::new (__f_) _FF(__f);
+        }
+        else
+        {
+            typedef allocator<_FF> _Ap;
+            _Ap __a;
+            typedef __allocator_destructor<_Ap> _Dp;
+            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+            ::new (__hold.get()) _FF(__f, allocator<_Fp>(__a));
+            __f_ = __hold.release();
+        }
+    }
+}
+
+template<class _Rp, class _A0, class _A1, class _A2>
+template <class _Fp, class _Alloc>
+function<_Rp(_A0, _A1, _A2)>::function(allocator_arg_t, const _Alloc& __a0, _Fp __f,
+                                     typename enable_if<!is_integral<_Fp>::value>::type*)
+    : __f_(0)
+{
+    typedef allocator_traits<_Alloc> __alloc_traits;
+    if (__not_null(__f))
+    {
+        typedef __function::__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)> _FF;
+        if (sizeof(_FF) <= sizeof(__buf_))
+        {
+            __f_ = (__base*)&__buf_;
+            ::new (__f_) _FF(__f, __a0);
+        }
+        else
+        {
+            typedef typename __rebind_alloc_helper<__alloc_traits, _FF>::type _Ap;
+            _Ap __a(__a0);
+            typedef __allocator_destructor<_Ap> _Dp;
+            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+            ::new (__hold.get()) _FF(__f, _Alloc(__a));
+            __f_ = __hold.release();
+        }
+    }
+}
+
+template<class _Rp, class _A0, class _A1, class _A2>
+function<_Rp(_A0, _A1, _A2)>&
+function<_Rp(_A0, _A1, _A2)>::operator=(const function& __f)
+{
+    function(__f).swap(*this);
+    return *this;
+}
+
+template<class _Rp, class _A0, class _A1, class _A2>
+function<_Rp(_A0, _A1, _A2)>&
+function<_Rp(_A0, _A1, _A2)>::operator=(nullptr_t)
+{
+    if (__f_ == (__base*)&__buf_)
+        __f_->destroy();
+    else if (__f_)
+        __f_->destroy_deallocate();
+    __f_ = 0;
+    return *this;
+}
+
+template<class _Rp, class _A0, class _A1, class _A2>
+template <class _Fp>
+typename enable_if
+<
+    !is_integral<_Fp>::value,
+    function<_Rp(_A0, _A1, _A2)>&
+>::type
+function<_Rp(_A0, _A1, _A2)>::operator=(_Fp __f)
+{
+    function(_VSTD::move(__f)).swap(*this);
+    return *this;
+}
+
+template<class _Rp, class _A0, class _A1, class _A2>
+function<_Rp(_A0, _A1, _A2)>::~function()
+{
+    if (__f_ == (__base*)&__buf_)
+        __f_->destroy();
+    else if (__f_)
+        __f_->destroy_deallocate();
+}
+
+template<class _Rp, class _A0, class _A1, class _A2>
+void
+function<_Rp(_A0, _A1, _A2)>::swap(function& __f)
+{
+    if (__f_ == (__base*)&__buf_ && __f.__f_ == (__base*)&__f.__buf_)
+    {
+        typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
+        __base* __t = (__base*)&__tempbuf;
+        __f_->__clone(__t);
+        __f_->destroy();
+        __f_ = 0;
+        __f.__f_->__clone((__base*)&__buf_);
+        __f.__f_->destroy();
+        __f.__f_ = 0;
+        __f_ = (__base*)&__buf_;
+        __t->__clone((__base*)&__f.__buf_);
+        __t->destroy();
+        __f.__f_ = (__base*)&__f.__buf_;
+    }
+    else if (__f_ == (__base*)&__buf_)
+    {
+        __f_->__clone((__base*)&__f.__buf_);
+        __f_->destroy();
+        __f_ = __f.__f_;
+        __f.__f_ = (__base*)&__f.__buf_;
+    }
+    else if (__f.__f_ == (__base*)&__f.__buf_)
+    {
+        __f.__f_->__clone((__base*)&__buf_);
+        __f.__f_->destroy();
+        __f.__f_ = __f_;
+        __f_ = (__base*)&__buf_;
+    }
+    else
+        _VSTD::swap(__f_, __f.__f_);
+}
+
+template<class _Rp, class _A0, class _A1, class _A2>
+_Rp
+function<_Rp(_A0, _A1, _A2)>::operator()(_A0 __a0, _A1 __a1, _A2 __a2) const
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__f_ == 0)
+        throw bad_function_call();
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return (*__f_)(__a0, __a1, __a2);
+}
+
+#ifndef _LIBCPP_NO_RTTI
+
+template<class _Rp, class _A0, class _A1, class _A2>
+const std::type_info&
+function<_Rp(_A0, _A1, _A2)>::target_type() const
+{
+    if (__f_ == 0)
+        return typeid(void);
+    return __f_->target_type();
+}
+
+template<class _Rp, class _A0, class _A1, class _A2>
+template <typename _Tp>
+_Tp*
+function<_Rp(_A0, _A1, _A2)>::target()
+{
+    if (__f_ == 0)
+        return (_Tp*)0;
+    return (_Tp*)__f_->target(typeid(_Tp));
+}
+
+template<class _Rp, class _A0, class _A1, class _A2>
+template <typename _Tp>
+const _Tp*
+function<_Rp(_A0, _A1, _A2)>::target() const
+{
+    if (__f_ == 0)
+        return (const _Tp*)0;
+    return (const _Tp*)__f_->target(typeid(_Tp));
+}
+
+#endif  // _LIBCPP_NO_RTTI
+
+template <class _Fp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const function<_Fp>& __f, nullptr_t) {return !__f;}
+
+template <class _Fp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(nullptr_t, const function<_Fp>& __f) {return !__f;}
+
+template <class _Fp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const function<_Fp>& __f, nullptr_t) {return (bool)__f;}
+
+template <class _Fp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(nullptr_t, const function<_Fp>& __f) {return (bool)__f;}
+
+template <class _Fp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(function<_Fp>& __x, function<_Fp>& __y)
+{return __x.swap(__y);}
+
+#endif  // _LIBCPP_FUNCTIONAL_03

diff --git a/libcxx/include/__functional_base b/libcxx/include/__functional_base
new file mode 100644
index 0000000..3ff2e35
--- /dev/null
+++ b/libcxx/include/__functional_base

@@ -0,0 +1,721 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_FUNCTIONAL_BASE
+#define _LIBCPP_FUNCTIONAL_BASE
+
+#include <__config>
+#include <type_traits>
+#include <typeinfo>
+#include <exception>
+#include <new>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Arg, class _Result>
+struct _LIBCPP_TYPE_VIS_ONLY unary_function
+{
+    typedef _Arg    argument_type;
+    typedef _Result result_type;
+};
+
+template <class _Arg1, class _Arg2, class _Result>
+struct _LIBCPP_TYPE_VIS_ONLY binary_function
+{
+    typedef _Arg1   first_argument_type;
+    typedef _Arg2   second_argument_type;
+    typedef _Result result_type;
+};
+
+template <class _Tp> struct _LIBCPP_TYPE_VIS_ONLY hash;
+
+template <class _Tp>
+struct __has_result_type
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Up> static __two __test(...);
+    template <class _Up> static char __test(typename _Up::result_type* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY less : binary_function<_Tp, _Tp, bool>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY 
+    bool operator()(const _Tp& __x, const _Tp& __y) const
+        {return __x < __y;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY less<void>
+{
+    template <class _T1, class _T2> 
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_T1&& __t, _T2&& __u) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) < _VSTD::forward<_T2>(__u)))
+    -> decltype        (_VSTD::forward<_T1>(__t) < _VSTD::forward<_T2>(__u))
+        { return        _VSTD::forward<_T1>(__t) < _VSTD::forward<_T2>(__u); }
+    typedef void is_transparent;
+};
+#endif
+
+// addressof
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp*
+addressof(_Tp& __x) _NOEXCEPT
+{
+    return (_Tp*)&reinterpret_cast<const volatile char&>(__x);
+}
+
+#if defined(_LIBCPP_HAS_OBJC_ARC) && !defined(_LIBCPP_PREDEFINED_OBJC_ARC_ADDRESSOF)
+// Objective-C++ Automatic Reference Counting uses qualified pointers
+// that require special addressof() signatures. When
+// _LIBCPP_PREDEFINED_OBJC_ARC_ADDRESSOF is defined, the compiler
+// itself is providing these definitions. Otherwise, we provide them.
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+__strong _Tp*
+addressof(__strong _Tp& __x) _NOEXCEPT
+{
+  return &__x;
+}
+
+#ifdef _LIBCPP_HAS_OBJC_ARC_WEAK
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+__weak _Tp*
+addressof(__weak _Tp& __x) _NOEXCEPT
+{
+  return &__x;
+}
+#endif
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+__autoreleasing _Tp*
+addressof(__autoreleasing _Tp& __x) _NOEXCEPT
+{
+  return &__x;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+__unsafe_unretained _Tp*
+addressof(__unsafe_unretained _Tp& __x) _NOEXCEPT
+{
+  return &__x;
+}
+#endif
+
+
+// __weak_result_type
+
+template <class _Tp>
+struct __derives_from_unary_function
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    static __two __test(...);
+    template <class _Ap, class _Rp>
+        static unary_function<_Ap, _Rp>
+        __test(const volatile unary_function<_Ap, _Rp>*);
+public:
+    static const bool value = !is_same<decltype(__test((_Tp*)0)), __two>::value;
+    typedef decltype(__test((_Tp*)0)) type;
+};
+
+template <class _Tp>
+struct __derives_from_binary_function
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    static __two __test(...);
+    template <class _A1, class _A2, class _Rp>
+        static binary_function<_A1, _A2, _Rp>
+        __test(const volatile binary_function<_A1, _A2, _Rp>*);
+public:
+    static const bool value = !is_same<decltype(__test((_Tp*)0)), __two>::value;
+    typedef decltype(__test((_Tp*)0)) type;
+};
+
+template <class _Tp, bool = __derives_from_unary_function<_Tp>::value>
+struct __maybe_derive_from_unary_function  // bool is true
+    : public __derives_from_unary_function<_Tp>::type
+{
+};
+
+template <class _Tp>
+struct __maybe_derive_from_unary_function<_Tp, false>
+{
+};
+
+template <class _Tp, bool = __derives_from_binary_function<_Tp>::value>
+struct __maybe_derive_from_binary_function  // bool is true
+    : public __derives_from_binary_function<_Tp>::type
+{
+};
+
+template <class _Tp>
+struct __maybe_derive_from_binary_function<_Tp, false>
+{
+};
+
+template <class _Tp, bool = __has_result_type<_Tp>::value>
+struct __weak_result_type_imp // bool is true
+    : public __maybe_derive_from_unary_function<_Tp>,
+      public __maybe_derive_from_binary_function<_Tp>
+{
+    typedef typename _Tp::result_type result_type;
+};
+
+template <class _Tp>
+struct __weak_result_type_imp<_Tp, false>
+    : public __maybe_derive_from_unary_function<_Tp>,
+      public __maybe_derive_from_binary_function<_Tp>
+{
+};
+
+template <class _Tp>
+struct __weak_result_type
+    : public __weak_result_type_imp<_Tp>
+{
+};
+
+// 0 argument case
+
+template <class _Rp>
+struct __weak_result_type<_Rp ()>
+{
+    typedef _Rp result_type;
+};
+
+template <class _Rp>
+struct __weak_result_type<_Rp (&)()>
+{
+    typedef _Rp result_type;
+};
+
+template <class _Rp>
+struct __weak_result_type<_Rp (*)()>
+{
+    typedef _Rp result_type;
+};
+
+// 1 argument case
+
+template <class _Rp, class _A1>
+struct __weak_result_type<_Rp (_A1)>
+    : public unary_function<_A1, _Rp>
+{
+};
+
+template <class _Rp, class _A1>
+struct __weak_result_type<_Rp (&)(_A1)>
+    : public unary_function<_A1, _Rp>
+{
+};
+
+template <class _Rp, class _A1>
+struct __weak_result_type<_Rp (*)(_A1)>
+    : public unary_function<_A1, _Rp>
+{
+};
+
+template <class _Rp, class _Cp>
+struct __weak_result_type<_Rp (_Cp::*)()>
+    : public unary_function<_Cp*, _Rp>
+{
+};
+
+template <class _Rp, class _Cp>
+struct __weak_result_type<_Rp (_Cp::*)() const>
+    : public unary_function<const _Cp*, _Rp>
+{
+};
+
+template <class _Rp, class _Cp>
+struct __weak_result_type<_Rp (_Cp::*)() volatile>
+    : public unary_function<volatile _Cp*, _Rp>
+{
+};
+
+template <class _Rp, class _Cp>
+struct __weak_result_type<_Rp (_Cp::*)() const volatile>
+    : public unary_function<const volatile _Cp*, _Rp>
+{
+};
+
+// 2 argument case
+
+template <class _Rp, class _A1, class _A2>
+struct __weak_result_type<_Rp (_A1, _A2)>
+    : public binary_function<_A1, _A2, _Rp>
+{
+};
+
+template <class _Rp, class _A1, class _A2>
+struct __weak_result_type<_Rp (*)(_A1, _A2)>
+    : public binary_function<_A1, _A2, _Rp>
+{
+};
+
+template <class _Rp, class _A1, class _A2>
+struct __weak_result_type<_Rp (&)(_A1, _A2)>
+    : public binary_function<_A1, _A2, _Rp>
+{
+};
+
+template <class _Rp, class _Cp, class _A1>
+struct __weak_result_type<_Rp (_Cp::*)(_A1)>
+    : public binary_function<_Cp*, _A1, _Rp>
+{
+};
+
+template <class _Rp, class _Cp, class _A1>
+struct __weak_result_type<_Rp (_Cp::*)(_A1) const>
+    : public binary_function<const _Cp*, _A1, _Rp>
+{
+};
+
+template <class _Rp, class _Cp, class _A1>
+struct __weak_result_type<_Rp (_Cp::*)(_A1) volatile>
+    : public binary_function<volatile _Cp*, _A1, _Rp>
+{
+};
+
+template <class _Rp, class _Cp, class _A1>
+struct __weak_result_type<_Rp (_Cp::*)(_A1) const volatile>
+    : public binary_function<const volatile _Cp*, _A1, _Rp>
+{
+};
+
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+// 3 or more arguments
+
+template <class _Rp, class _A1, class _A2, class _A3, class ..._A4>
+struct __weak_result_type<_Rp (_A1, _A2, _A3, _A4...)>
+{
+    typedef _Rp result_type;
+};
+
+template <class _Rp, class _A1, class _A2, class _A3, class ..._A4>
+struct __weak_result_type<_Rp (&)(_A1, _A2, _A3, _A4...)>
+{
+    typedef _Rp result_type;
+};
+
+template <class _Rp, class _A1, class _A2, class _A3, class ..._A4>
+struct __weak_result_type<_Rp (*)(_A1, _A2, _A3, _A4...)>
+{
+    typedef _Rp result_type;
+};
+
+template <class _Rp, class _Cp, class _A1, class _A2, class ..._A3>
+struct __weak_result_type<_Rp (_Cp::*)(_A1, _A2, _A3...)>
+{
+    typedef _Rp result_type;
+};
+
+template <class _Rp, class _Cp, class _A1, class _A2, class ..._A3>
+struct __weak_result_type<_Rp (_Cp::*)(_A1, _A2, _A3...) const>
+{
+    typedef _Rp result_type;
+};
+
+template <class _Rp, class _Cp, class _A1, class _A2, class ..._A3>
+struct __weak_result_type<_Rp (_Cp::*)(_A1, _A2, _A3...) volatile>
+{
+    typedef _Rp result_type;
+};
+
+template <class _Rp, class _Cp, class _A1, class _A2, class ..._A3>
+struct __weak_result_type<_Rp (_Cp::*)(_A1, _A2, _A3...) const volatile>
+{
+    typedef _Rp result_type;
+};
+
+#endif // _LIBCPP_HAS_NO_VARIADICS
+
+// __invoke
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+// bullets 1 and 2
+
+template <class _Fp, class _A0, class ..._Args,
+            class>
+inline _LIBCPP_INLINE_VISIBILITY
+auto
+__invoke(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
+    -> decltype((_VSTD::forward<_A0>(__a0).*__f)(_VSTD::forward<_Args>(__args)...))
+{
+    return (_VSTD::forward<_A0>(__a0).*__f)(_VSTD::forward<_Args>(__args)...);
+}
+
+template <class _Fp, class _A0, class ..._Args,
+            class>
+inline _LIBCPP_INLINE_VISIBILITY
+auto
+__invoke(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
+    -> decltype(((*_VSTD::forward<_A0>(__a0)).*__f)(_VSTD::forward<_Args>(__args)...))
+{
+    return ((*_VSTD::forward<_A0>(__a0)).*__f)(_VSTD::forward<_Args>(__args)...);
+}
+
+// bullets 3 and 4
+
+template <class _Fp, class _A0,
+            class>
+inline _LIBCPP_INLINE_VISIBILITY
+auto
+__invoke(_Fp&& __f, _A0&& __a0)
+    -> decltype(_VSTD::forward<_A0>(__a0).*__f)
+{
+    return _VSTD::forward<_A0>(__a0).*__f;
+}
+
+template <class _Fp, class _A0,
+            class>
+inline _LIBCPP_INLINE_VISIBILITY
+auto
+__invoke(_Fp&& __f, _A0&& __a0)
+    -> decltype((*_VSTD::forward<_A0>(__a0)).*__f)
+{
+    return (*_VSTD::forward<_A0>(__a0)).*__f;
+}
+
+// bullet 5
+
+template <class _Fp, class ..._Args>
+inline _LIBCPP_INLINE_VISIBILITY
+auto
+__invoke(_Fp&& __f, _Args&& ...__args)
+    -> decltype(_VSTD::forward<_Fp>(__f)(_VSTD::forward<_Args>(__args)...))
+{
+    return _VSTD::forward<_Fp>(__f)(_VSTD::forward<_Args>(__args)...);
+}
+template <class _Tp, class ..._Args>
+struct __invoke_return
+{
+    typedef decltype(__invoke(_VSTD::declval<_Tp>(), _VSTD::declval<_Args>()...)) type;
+};
+
+#else // _LIBCPP_HAS_NO_VARIADICS
+
+#include <__functional_base_03>
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+
+template <class _Ret>
+struct __invoke_void_return_wrapper
+{
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    template <class ..._Args>
+    static _Ret __call(_Args&&... __args) {
+        return __invoke(_VSTD::forward<_Args>(__args)...);
+    }
+#else
+    template <class _Fn>
+    static _Ret __call(_Fn __f) {
+        return __invoke(__f);
+    }
+
+    template <class _Fn, class _A0>
+    static _Ret __call(_Fn __f, _A0& __a0) {
+        return __invoke(__f, __a0);
+    }
+
+    template <class _Fn, class _A0, class _A1>
+    static _Ret __call(_Fn __f, _A0& __a0, _A1& __a1) {
+        return __invoke(__f, __a0, __a1);
+    }
+
+    template <class _Fn, class _A0, class _A1, class _A2>
+    static _Ret __call(_Fn __f, _A0& __a0, _A1& __a1, _A2& __a2){
+        return __invoke(__f, __a0, __a1, __a2);
+    }
+#endif
+};
+
+template <>
+struct __invoke_void_return_wrapper<void>
+{
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    template <class ..._Args>
+    static void __call(_Args&&... __args) {
+        __invoke(_VSTD::forward<_Args>(__args)...);
+    }
+#else
+    template <class _Fn>
+    static void __call(_Fn __f) {
+        __invoke(__f);
+    }
+
+    template <class _Fn, class _A0>
+    static void __call(_Fn __f, _A0& __a0) {
+        __invoke(__f, __a0);
+    }
+
+    template <class _Fn, class _A0, class _A1>
+    static void __call(_Fn __f, _A0& __a0, _A1& __a1) {
+        __invoke(__f, __a0, __a1);
+    }
+
+    template <class _Fn, class _A0, class _A1, class _A2>
+    static void __call(_Fn __f, _A0& __a0, _A1& __a1, _A2& __a2) {
+        __invoke(__f, __a0, __a1, __a2);
+    }
+#endif
+};
+
+template <class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY reference_wrapper
+    : public __weak_result_type<_Tp>
+{
+public:
+    // types
+    typedef _Tp type;
+private:
+    type* __f_;
+
+public:
+    // construct/copy/destroy
+    _LIBCPP_INLINE_VISIBILITY reference_wrapper(type& __f) _NOEXCEPT
+        : __f_(_VSTD::addressof(__f)) {}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    private: reference_wrapper(type&&); public: // = delete; // do not bind to temps
+#endif
+
+    // access
+    _LIBCPP_INLINE_VISIBILITY operator type&    () const _NOEXCEPT {return *__f_;}
+    _LIBCPP_INLINE_VISIBILITY          type& get() const _NOEXCEPT {return *__f_;}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    // invoke
+    template <class... _ArgTypes>
+       _LIBCPP_INLINE_VISIBILITY
+       typename __invoke_of<type&, _ArgTypes...>::type
+          operator() (_ArgTypes&&... __args) const
+          {
+              return __invoke(get(), _VSTD::forward<_ArgTypes>(__args)...);
+          }
+#else
+
+    _LIBCPP_INLINE_VISIBILITY
+    typename __invoke_return<type>::type
+       operator() () const
+       {
+           return __invoke(get());
+       }
+
+    template <class _A0>
+       _LIBCPP_INLINE_VISIBILITY
+       typename __invoke_return0<type&, _A0>::type
+          operator() (_A0& __a0) const
+          {
+              return __invoke<type&, _A0>(get(), __a0);
+          }
+
+    template <class _A0, class _A1>
+       _LIBCPP_INLINE_VISIBILITY
+       typename __invoke_return1<type&, _A0, _A1>::type
+          operator() (_A0& __a0, _A1& __a1) const
+          {
+              return __invoke<type&, _A0, _A1>(get(), __a0, __a1);
+          }
+
+    template <class _A0, class _A1, class _A2>
+       _LIBCPP_INLINE_VISIBILITY
+       typename __invoke_return2<type&, _A0, _A1, _A2>::type
+          operator() (_A0& __a0, _A1& __a1, _A2& __a2) const
+          {
+              return __invoke<type&, _A0, _A1, _A2>(get(), __a0, __a1, __a2);
+          }
+#endif // _LIBCPP_HAS_NO_VARIADICS
+};
+
+template <class _Tp> struct __is_reference_wrapper_impl : public false_type {};
+template <class _Tp> struct __is_reference_wrapper_impl<reference_wrapper<_Tp> > : public true_type {};
+template <class _Tp> struct __is_reference_wrapper
+    : public __is_reference_wrapper_impl<typename remove_cv<_Tp>::type> {};
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+reference_wrapper<_Tp>
+ref(_Tp& __t) _NOEXCEPT
+{
+    return reference_wrapper<_Tp>(__t);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+reference_wrapper<_Tp>
+ref(reference_wrapper<_Tp> __t) _NOEXCEPT
+{
+    return ref(__t.get());
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+reference_wrapper<const _Tp>
+cref(const _Tp& __t) _NOEXCEPT
+{
+    return reference_wrapper<const _Tp>(__t);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+reference_wrapper<const _Tp>
+cref(reference_wrapper<_Tp> __t) _NOEXCEPT
+{
+    return cref(__t.get());
+}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#ifndef _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+
+template <class _Tp> void ref(const _Tp&&) = delete;
+template <class _Tp> void cref(const _Tp&&) = delete;
+
+#else  // _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+
+template <class _Tp> void ref(const _Tp&&);// = delete;
+template <class _Tp> void cref(const _Tp&&);// = delete;
+
+#endif  // _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp1, class _Tp2 = void>
+struct __is_transparent
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Up> static __two __test(...);
+    template <class _Up> static char __test(typename _Up::is_transparent* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp1>(0)) == 1;
+};
+#endif
+
+// allocator_arg_t
+
+struct _LIBCPP_TYPE_VIS_ONLY allocator_arg_t { };
+
+#if defined(_LIBCPP_HAS_NO_CONSTEXPR) || defined(_LIBCPP_BUILDING_MEMORY)
+extern const allocator_arg_t allocator_arg;
+#else
+constexpr allocator_arg_t allocator_arg = allocator_arg_t();
+#endif
+
+// uses_allocator
+
+template <class _Tp>
+struct __has_allocator_type
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Up> static __two __test(...);
+    template <class _Up> static char __test(typename _Up::allocator_type* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+template <class _Tp, class _Alloc, bool = __has_allocator_type<_Tp>::value>
+struct __uses_allocator
+    : public integral_constant<bool,
+        is_convertible<_Alloc, typename _Tp::allocator_type>::value>
+{
+};
+
+template <class _Tp, class _Alloc>
+struct __uses_allocator<_Tp, _Alloc, false>
+    : public false_type
+{
+};
+
+template <class _Tp, class _Alloc>
+struct _LIBCPP_TYPE_VIS_ONLY uses_allocator
+    : public __uses_allocator<_Tp, _Alloc>
+{
+};
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+// allocator construction
+
+template <class _Tp, class _Alloc, class ..._Args>
+struct __uses_alloc_ctor_imp
+{
+    static const bool __ua = uses_allocator<_Tp, _Alloc>::value;
+    static const bool __ic =
+        is_constructible<_Tp, allocator_arg_t, _Alloc, _Args...>::value;
+    static const int value = __ua ? 2 - __ic : 0;
+};
+
+template <class _Tp, class _Alloc, class ..._Args>
+struct __uses_alloc_ctor
+    : integral_constant<int, __uses_alloc_ctor_imp<_Tp, _Alloc, _Args...>::value>
+    {};
+
+template <class _Tp, class _Allocator, class... _Args>
+inline _LIBCPP_INLINE_VISIBILITY
+void __user_alloc_construct_impl (integral_constant<int, 0>, _Tp *__storage, const _Allocator &, _Args &&... __args )
+{
+    new (__storage) _Tp (_VSTD::forward<_Args>(__args)...);
+}
+
+template <class _Tp, class _Allocator, class... _Args>
+inline _LIBCPP_INLINE_VISIBILITY
+void __user_alloc_construct_impl (integral_constant<int, 1>, _Tp *__storage, const _Allocator &__a, _Args &&... __args )
+{
+    new (__storage) _Tp (allocator_arg, __a, _VSTD::forward<_Args>(__args)...);
+}
+
+template <class _Tp, class _Allocator, class... _Args>
+inline _LIBCPP_INLINE_VISIBILITY
+void __user_alloc_construct_impl (integral_constant<int, 2>, _Tp *__storage, const _Allocator &__a, _Args &&... __args )
+{
+    new (__storage) _Tp (_VSTD::forward<_Args>(__args)..., __a);
+}
+
+template <class _Tp, class _Allocator, class... _Args>
+inline _LIBCPP_INLINE_VISIBILITY
+void __user_alloc_construct (_Tp *__storage, const _Allocator &__a, _Args &&... __args)
+{ 
+    __user_alloc_construct_impl( 
+             __uses_alloc_ctor<_Tp, _Allocator>(), 
+             __storage, __a, _VSTD::forward<_Args>(__args)...
+        );
+}
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_FUNCTIONAL_BASE

diff --git a/libcxx/include/__functional_base_03 b/libcxx/include/__functional_base_03
new file mode 100644
index 0000000..0a7ff62
--- /dev/null
+++ b/libcxx/include/__functional_base_03

@@ -0,0 +1,524 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_FUNCTIONAL_BASE_03
+#define _LIBCPP_FUNCTIONAL_BASE_03
+
+// manual variadic expansion for <functional>
+
+// __invoke
+// first bullet
+
+template <class _Rp, class _Tp, class _T1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(), _T1& __t1)
+{
+    return (__t1.*__f)();
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0), _T1& __t1, _A0& __a0)
+{
+    return (__t1.*__f)(__a0);
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0, class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0, _A1), _T1& __t1, _A0& __a0, _A1& __a1)
+{
+    return (__t1.*__f)(__a0, __a1);
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0, class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0, _A1, _A2), _T1& __t1, _A0& __a0, _A1& __a1, _A2& __a2)
+{
+    return (__t1.*__f)(__a0, __a1, __a2);
+}
+
+template <class _Rp, class _Tp, class _T1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)() const, _T1& __t1)
+{
+    return (__t1.*__f)();
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0) const, _T1& __t1, _A0& __a0)
+{
+    return (__t1.*__f)(__a0);
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0, class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0, _A1) const, _T1& __t1, _A0& __a0, _A1& __a1)
+{
+    return (__t1.*__f)(__a0, __a1);
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0, class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0, _A1, _A2) const, _T1& __t1, _A0& __a0, _A1& __a1, _A2& __a2)
+{
+    return (__t1.*__f)(__a0, __a1, __a2);
+}
+
+template <class _Rp, class _Tp, class _T1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)() volatile, _T1& __t1)
+{
+    return (__t1.*__f)();
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0) volatile, _T1& __t1, _A0& __a0)
+{
+    return (__t1.*__f)(__a0);
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0, class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0, _A1) volatile, _T1& __t1, _A0& __a0, _A1& __a1)
+{
+    return (__t1.*__f)(__a0, __a1);
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0, class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0, _A1, _A2) volatile, _T1& __t1, _A0& __a0, _A1& __a1, _A2& __a2)
+{
+    return (__t1.*__f)(__a0, __a1, __a2);
+}
+
+template <class _Rp, class _Tp, class _T1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)() const volatile, _T1& __t1)
+{
+    return (__t1.*__f)();
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0) const volatile, _T1& __t1, _A0& __a0)
+{
+    return (__t1.*__f)(__a0);
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0, class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0, _A1) const volatile, _T1& __t1, _A0& __a0, _A1& __a1)
+{
+    return (__t1.*__f)(__a0, __a1);
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0, class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0, _A1, _A2) const volatile, _T1& __t1, _A0& __a0, _A1& __a1, _A2& __a2)
+{
+    return (__t1.*__f)(__a0, __a1, __a2);
+}
+
+// second bullet
+
+template <class _Rp, class _Tp, class _T1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(), _T1 __t1)
+{
+    return ((*__t1).*__f)();
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0), _T1 __t1, _A0& __a0)
+{
+    return ((*__t1).*__f)(__a0);
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0, class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0, _A1), _T1 __t1, _A0& __a0, _A1& __a1)
+{
+    return ((*__t1).*__f)(__a0, __a1);
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0, class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0, _A1, _A2), _T1 __t1, _A0& __a0, _A1& __a1, _A2& __a2)
+{
+    return ((*__t1).*__f)(__a0, __a1, __a2);
+}
+
+template <class _Rp, class _Tp, class _T1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)() const, _T1 __t1)
+{
+    return ((*__t1).*__f)();
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0) const, _T1 __t1, _A0& __a0)
+{
+    return ((*__t1).*__f)(__a0);
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0, class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0, _A1) const, _T1 __t1, _A0& __a0, _A1& __a1)
+{
+    return ((*__t1).*__f)(__a0, __a1);
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0, class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0, _A1, _A2) const, _T1 __t1, _A0& __a0, _A1& __a1, _A2& __a2)
+{
+    return ((*__t1).*__f)(__a0, __a1, __a2);
+}
+
+template <class _Rp, class _Tp, class _T1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)() volatile, _T1 __t1)
+{
+    return ((*__t1).*__f)();
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0) volatile, _T1 __t1, _A0& __a0)
+{
+    return ((*__t1).*__f)(__a0);
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0, class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0, _A1) volatile, _T1 __t1, _A0& __a0, _A1& __a1)
+{
+    return ((*__t1).*__f)(__a0, __a1);
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0, class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0, _A1, _A2) volatile, _T1 __t1, _A0& __a0, _A1& __a1, _A2& __a2)
+{
+    return ((*__t1).*__f)(__a0, __a1, __a2);
+}
+
+template <class _Rp, class _Tp, class _T1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)() const volatile, _T1 __t1)
+{
+    return ((*__t1).*__f)();
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0) const volatile, _T1 __t1, _A0& __a0)
+{
+    return ((*__t1).*__f)(__a0);
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0, class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0, _A1) const volatile, _T1 __t1, _A0& __a0, _A1& __a1)
+{
+    return ((*__t1).*__f)(__a0, __a1);
+}
+
+template <class _Rp, class _Tp, class _T1, class _A0, class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+    _Rp
+>::type
+__invoke(_Rp (_Tp::*__f)(_A0, _A1, _A2) const volatile, _T1 __t1, _A0& __a0, _A1& __a1, _A2& __a2)
+{
+    return ((*__t1).*__f)(__a0, __a1, __a2);
+}
+
+// third bullet
+
+template <class _Rp, class _Tp, class _T1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_member_object_pointer<_Rp _Tp::*>::value &&
+    is_base_of<_Tp, typename remove_reference<_T1>::type>::value,
+   __apply_cv<_T1, _Rp>
+>::type::type&
+__invoke(_Rp _Tp::* __f, _T1& __t1)
+{
+    return __t1.*__f;
+}
+
+
+// forth bullet
+
+template <class _T1, class _Rp, bool>
+struct __4th_helper
+{
+};
+
+template <class _T1, class _Rp>
+struct __4th_helper<_T1, _Rp, true>
+{
+    typedef typename __apply_cv<decltype(*_VSTD::declval<_T1&>()), _Rp>::type type;
+};
+
+template <class _Rp, class _Tp, class _T1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __4th_helper<_T1, _Rp,
+    is_member_object_pointer<_Rp _Tp::*>::value &&
+    !is_base_of<_Tp, typename remove_reference<_T1>::type>::value
+>::type&
+__invoke(_Rp _Tp::* __f, _T1& __t1)
+{
+    return (*__t1).*__f;
+}
+
+// fifth bullet
+
+template <class _Fp>
+inline _LIBCPP_INLINE_VISIBILITY
+decltype(_VSTD::declval<_Fp&>()())
+__invoke(_Fp& __f)
+{
+    return __f();
+}
+
+template <class _Fp, class _A0>
+inline _LIBCPP_INLINE_VISIBILITY
+decltype(_VSTD::declval<_Fp&>()(_VSTD::declval<_A0&>()))
+__invoke(_Fp& __f, _A0& __a0)
+{
+    return __f(__a0);
+}
+
+template <class _Fp, class _A0, class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+decltype(_VSTD::declval<_Fp&>()(_VSTD::declval<_A0&>(), _VSTD::declval<_A1&>()))
+__invoke(_Fp& __f, _A0& __a0, _A1& __a1)
+{
+    return __f(__a0, __a1);
+}
+
+template <class _Fp, class _A0, class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+decltype(_VSTD::declval<_Fp&>()(_VSTD::declval<_A0&>(), _VSTD::declval<_A1&>(), _VSTD::declval<_A2&>()))
+__invoke(_Fp& __f, _A0& __a0, _A1& __a1, _A2& __a2)
+{
+    return __f(__a0, __a1, __a2);
+}
+
+template <class _Fp, bool = __has_result_type<__weak_result_type<_Fp> >::value>
+struct __invoke_return
+{
+    typedef typename __weak_result_type<_Fp>::result_type type;
+};
+
+template <class _Fp>
+struct __invoke_return<_Fp, false>
+{
+    typedef decltype(__invoke(_VSTD::declval<_Fp&>())) type;
+};
+
+template <class _Tp, class _A0, bool = is_member_object_pointer<_Tp>::value>
+struct __invoke_return0
+{
+    typedef decltype(__invoke(_VSTD::declval<_Tp&>(), _VSTD::declval<_A0&>())) type;
+};
+
+template <class _Rp, class _Tp, class _A0>
+struct __invoke_return0<_Rp _Tp::*, _A0, true>
+{
+    typedef typename __apply_cv<_A0, _Rp>::type& type;
+};
+
+template <class _Rp, class _Tp, class _A0>
+struct __invoke_return0<_Rp _Tp::*, _A0*, true>
+{
+    typedef typename __apply_cv<_A0, _Rp>::type& type;
+};
+
+template <class _Tp, class _A0, class _A1>
+struct __invoke_return1
+{
+    typedef decltype(__invoke(_VSTD::declval<_Tp&>(), _VSTD::declval<_A0&>(),
+                                                     _VSTD::declval<_A1&>())) type;
+};
+
+template <class _Tp, class _A0, class _A1, class _A2>
+struct __invoke_return2
+{
+    typedef decltype(__invoke(_VSTD::declval<_Tp&>(), _VSTD::declval<_A0&>(),
+                                                      _VSTD::declval<_A1&>(),
+                                                      _VSTD::declval<_A2&>())) type;
+};
+
+#endif  // _LIBCPP_FUNCTIONAL_BASE_03

diff --git a/libcxx/include/__hash_table b/libcxx/include/__hash_table
new file mode 100644
index 0000000..dac4cfd
--- /dev/null
+++ b/libcxx/include/__hash_table

@@ -0,0 +1,2455 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP__HASH_TABLE
+#define _LIBCPP__HASH_TABLE
+
+#include <__config>
+#include <initializer_list>
+#include <memory>
+#include <iterator>
+#include <algorithm>
+#include <cmath>
+
+#include <__undef_min_max>
+#include <__undef___deallocate>
+
+#include <__debug>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+_LIBCPP_FUNC_VIS
+size_t __next_prime(size_t __n);
+
+template <class _NodePtr>
+struct __hash_node_base
+{
+    typedef __hash_node_base __first_node;
+
+    _NodePtr    __next_;
+
+    _LIBCPP_INLINE_VISIBILITY __hash_node_base() _NOEXCEPT : __next_(nullptr) {}
+};
+
+template <class _Tp, class _VoidPtr>
+struct __hash_node
+    : public __hash_node_base
+             <
+                 typename pointer_traits<_VoidPtr>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+                     rebind<__hash_node<_Tp, _VoidPtr> >
+#else
+                     rebind<__hash_node<_Tp, _VoidPtr> >::other
+#endif
+             >
+{
+    typedef _Tp value_type;
+
+    size_t     __hash_;
+    value_type __value_;
+};
+
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+__is_hash_power2(size_t __bc)
+{
+    return __bc > 2 && !(__bc & (__bc - 1));
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+size_t
+__constrain_hash(size_t __h, size_t __bc)
+{
+    return !(__bc & (__bc - 1)) ? __h & (__bc - 1) : __h % __bc;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+size_t
+__next_hash_pow2(size_t __n)
+{
+    return size_t(1) << (std::numeric_limits<size_t>::digits - __clz(__n-1));
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc> class __hash_table;
+template <class _ConstNodePtr> class _LIBCPP_TYPE_VIS_ONLY __hash_const_iterator;
+template <class _HashIterator> class _LIBCPP_TYPE_VIS_ONLY __hash_map_iterator;
+template <class _HashIterator> class _LIBCPP_TYPE_VIS_ONLY __hash_map_const_iterator;
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+    class _LIBCPP_TYPE_VIS_ONLY unordered_map;
+
+template <class _NodePtr>
+class _LIBCPP_TYPE_VIS_ONLY __hash_iterator
+{
+    typedef _NodePtr __node_pointer;
+
+    __node_pointer            __node_;
+
+public:
+    typedef forward_iterator_tag                         iterator_category;
+    typedef typename pointer_traits<__node_pointer>::element_type::value_type value_type;
+    typedef typename pointer_traits<__node_pointer>::difference_type difference_type;
+    typedef value_type&                                  reference;
+    typedef typename pointer_traits<__node_pointer>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+                     rebind<value_type>
+#else
+                     rebind<value_type>::other
+#endif
+                                                         pointer;
+
+    _LIBCPP_INLINE_VISIBILITY __hash_iterator() _NOEXCEPT
+#if _LIBCPP_STD_VER > 11
+    : __node_(nullptr)
+#endif
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __get_db()->__insert_i(this);
+#endif
+    }
+
+#if _LIBCPP_DEBUG_LEVEL >= 2
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_iterator(const __hash_iterator& __i)
+        : __node_(__i.__node_)
+    {
+        __get_db()->__iterator_copy(this, &__i);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    ~__hash_iterator()
+    {
+        __get_db()->__erase_i(this);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_iterator& operator=(const __hash_iterator& __i)
+    {
+        if (this != &__i)
+        {
+            __get_db()->__iterator_copy(this, &__i);
+            __node_ = __i.__node_;
+        }
+        return *this;
+    }
+
+#endif  // _LIBCPP_DEBUG_LEVEL >= 2
+
+    _LIBCPP_INLINE_VISIBILITY
+        reference operator*() const
+        {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+            _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                           "Attempted to dereference a non-dereferenceable unordered container iterator");
+#endif
+            return __node_->__value_;
+        }
+    _LIBCPP_INLINE_VISIBILITY
+        pointer operator->() const
+        {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+            _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                           "Attempted to dereference a non-dereferenceable unordered container iterator");
+#endif
+            return pointer_traits<pointer>::pointer_to(__node_->__value_);
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_iterator& operator++()
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                       "Attempted to increment non-incrementable unordered container iterator");
+#endif
+        __node_ = __node_->__next_;
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_iterator operator++(int)
+    {
+        __hash_iterator __t(*this);
+        ++(*this);
+        return __t;
+    }
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator==(const __hash_iterator& __x, const __hash_iterator& __y)
+    {
+        return __x.__node_ == __y.__node_;
+    }
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(const __hash_iterator& __x, const __hash_iterator& __y)
+        {return !(__x == __y);}
+
+private:
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_iterator(__node_pointer __node, const void* __c) _NOEXCEPT
+        : __node_(__node)
+        {
+            __get_db()->__insert_ic(this, __c);
+        }
+#else
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_iterator(__node_pointer __node) _NOEXCEPT
+        : __node_(__node)
+        {}
+#endif
+
+    template <class, class, class, class> friend class __hash_table;
+    template <class> friend class _LIBCPP_TYPE_VIS_ONLY __hash_const_iterator;
+    template <class> friend class _LIBCPP_TYPE_VIS_ONLY __hash_map_iterator;
+    template <class, class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY unordered_map;
+    template <class, class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY unordered_multimap;
+};
+
+template <class _ConstNodePtr>
+class _LIBCPP_TYPE_VIS_ONLY __hash_const_iterator
+{
+    typedef _ConstNodePtr __node_pointer;
+
+    __node_pointer         __node_;
+
+    typedef typename remove_const<
+        typename pointer_traits<__node_pointer>::element_type
+                                 >::type __node;
+
+public:
+    typedef forward_iterator_tag                       iterator_category;
+    typedef typename __node::value_type                value_type;
+    typedef typename pointer_traits<__node_pointer>::difference_type difference_type;
+    typedef const value_type&                          reference;
+    typedef typename pointer_traits<__node_pointer>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<const value_type>
+#else
+            rebind<const value_type>::other
+#endif
+                                                       pointer;
+    typedef typename pointer_traits<__node_pointer>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<__node>
+#else
+            rebind<__node>::other
+#endif
+                                                      __non_const_node_pointer;
+    typedef __hash_iterator<__non_const_node_pointer> __non_const_iterator;
+
+    _LIBCPP_INLINE_VISIBILITY __hash_const_iterator() _NOEXCEPT
+#if _LIBCPP_STD_VER > 11
+    : __node_(nullptr)
+#endif
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __get_db()->__insert_i(this);
+#endif
+    }
+    _LIBCPP_INLINE_VISIBILITY 
+    __hash_const_iterator(const __non_const_iterator& __x) _NOEXCEPT
+        : __node_(__x.__node_)
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __get_db()->__iterator_copy(this, &__x);
+#endif
+    }
+
+#if _LIBCPP_DEBUG_LEVEL >= 2
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_const_iterator(const __hash_const_iterator& __i)
+        : __node_(__i.__node_)
+    {
+        __get_db()->__iterator_copy(this, &__i);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    ~__hash_const_iterator()
+    {
+        __get_db()->__erase_i(this);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_const_iterator& operator=(const __hash_const_iterator& __i)
+    {
+        if (this != &__i)
+        {
+            __get_db()->__iterator_copy(this, &__i);
+            __node_ = __i.__node_;
+        }
+        return *this;
+    }
+
+#endif  // _LIBCPP_DEBUG_LEVEL >= 2
+
+    _LIBCPP_INLINE_VISIBILITY
+        reference operator*() const
+        {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+            _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                           "Attempted to dereference a non-dereferenceable unordered container const_iterator");
+#endif
+            return __node_->__value_;
+        }
+    _LIBCPP_INLINE_VISIBILITY
+        pointer operator->() const
+        {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+            _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                           "Attempted to dereference a non-dereferenceable unordered container const_iterator");
+#endif
+            return pointer_traits<pointer>::pointer_to(__node_->__value_);
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_const_iterator& operator++()
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                       "Attempted to increment non-incrementable unordered container const_iterator");
+#endif
+        __node_ = __node_->__next_;
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_const_iterator operator++(int)
+    {
+        __hash_const_iterator __t(*this);
+        ++(*this);
+        return __t;
+    }
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator==(const __hash_const_iterator& __x, const __hash_const_iterator& __y)
+    {
+        return __x.__node_ == __y.__node_;
+    }
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(const __hash_const_iterator& __x, const __hash_const_iterator& __y)
+        {return !(__x == __y);}
+
+private:
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_const_iterator(__node_pointer __node, const void* __c) _NOEXCEPT
+        : __node_(__node)
+        {
+            __get_db()->__insert_ic(this, __c);
+        }
+#else
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_const_iterator(__node_pointer __node) _NOEXCEPT
+        : __node_(__node)
+        {}
+#endif
+
+    template <class, class, class, class> friend class __hash_table;
+    template <class> friend class _LIBCPP_TYPE_VIS_ONLY __hash_map_const_iterator;
+    template <class, class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY unordered_map;
+    template <class, class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY unordered_multimap;
+};
+
+template <class _ConstNodePtr> class _LIBCPP_TYPE_VIS_ONLY __hash_const_local_iterator;
+
+template <class _NodePtr>
+class _LIBCPP_TYPE_VIS_ONLY __hash_local_iterator
+{
+    typedef _NodePtr __node_pointer;
+
+    __node_pointer         __node_;
+    size_t                 __bucket_;
+    size_t                 __bucket_count_;
+
+    typedef pointer_traits<__node_pointer>          __pointer_traits;
+public:
+    typedef forward_iterator_tag                                iterator_category;
+    typedef typename __pointer_traits::element_type::value_type value_type;
+    typedef typename __pointer_traits::difference_type          difference_type;
+    typedef value_type&                                         reference;
+    typedef typename __pointer_traits::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<value_type>
+#else
+            rebind<value_type>::other
+#endif
+                                                                pointer;
+
+    _LIBCPP_INLINE_VISIBILITY __hash_local_iterator() _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __get_db()->__insert_i(this);
+#endif
+    }
+
+#if _LIBCPP_DEBUG_LEVEL >= 2
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_local_iterator(const __hash_local_iterator& __i)
+        : __node_(__i.__node_),
+          __bucket_(__i.__bucket_),
+          __bucket_count_(__i.__bucket_count_)
+    {
+        __get_db()->__iterator_copy(this, &__i);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    ~__hash_local_iterator()
+    {
+        __get_db()->__erase_i(this);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_local_iterator& operator=(const __hash_local_iterator& __i)
+    {
+        if (this != &__i)
+        {
+            __get_db()->__iterator_copy(this, &__i);
+            __node_ = __i.__node_;
+            __bucket_ = __i.__bucket_;
+            __bucket_count_ = __i.__bucket_count_;
+        }
+        return *this;
+    }
+
+#endif  // _LIBCPP_DEBUG_LEVEL >= 2
+
+    _LIBCPP_INLINE_VISIBILITY
+        reference operator*() const
+        {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+            _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                           "Attempted to dereference a non-dereferenceable unordered container local_iterator");
+#endif
+            return __node_->__value_;
+        }
+    _LIBCPP_INLINE_VISIBILITY
+        pointer operator->() const
+        {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+            _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                           "Attempted to dereference a non-dereferenceable unordered container local_iterator");
+#endif
+            return pointer_traits<pointer>::pointer_to(__node_->__value_);
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_local_iterator& operator++()
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                       "Attempted to increment non-incrementable unordered container local_iterator");
+#endif
+        __node_ = __node_->__next_;
+        if (__node_ != nullptr && __constrain_hash(__node_->__hash_, __bucket_count_) != __bucket_)
+            __node_ = nullptr;
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_local_iterator operator++(int)
+    {
+        __hash_local_iterator __t(*this);
+        ++(*this);
+        return __t;
+    }
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator==(const __hash_local_iterator& __x, const __hash_local_iterator& __y)
+    {
+        return __x.__node_ == __y.__node_;
+    }
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(const __hash_local_iterator& __x, const __hash_local_iterator& __y)
+        {return !(__x == __y);}
+
+private:
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_local_iterator(__node_pointer __node, size_t __bucket,
+                          size_t __bucket_count, const void* __c) _NOEXCEPT
+        : __node_(__node),
+          __bucket_(__bucket),
+          __bucket_count_(__bucket_count)
+        {
+            __get_db()->__insert_ic(this, __c);
+            if (__node_ != nullptr)
+                __node_ = __node_->__next_;
+        }
+#else
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_local_iterator(__node_pointer __node, size_t __bucket,
+                          size_t __bucket_count) _NOEXCEPT
+        : __node_(__node),
+          __bucket_(__bucket),
+          __bucket_count_(__bucket_count)
+        {
+            if (__node_ != nullptr)
+                __node_ = __node_->__next_;
+        }
+#endif
+    template <class, class, class, class> friend class __hash_table;
+    template <class> friend class _LIBCPP_TYPE_VIS_ONLY __hash_const_local_iterator;
+    template <class> friend class _LIBCPP_TYPE_VIS_ONLY __hash_map_iterator;
+};
+
+template <class _ConstNodePtr>
+class _LIBCPP_TYPE_VIS_ONLY __hash_const_local_iterator
+{
+    typedef _ConstNodePtr __node_pointer;
+
+    __node_pointer         __node_;
+    size_t                 __bucket_;
+    size_t                 __bucket_count_;
+
+    typedef pointer_traits<__node_pointer>          __pointer_traits;
+    typedef typename __pointer_traits::element_type __node;
+    typedef typename remove_const<__node>::type     __non_const_node;
+    typedef typename pointer_traits<__node_pointer>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<__non_const_node>
+#else
+            rebind<__non_const_node>::other
+#endif
+                                                    __non_const_node_pointer;
+    typedef __hash_local_iterator<__non_const_node_pointer>
+                                                    __non_const_iterator;
+public:
+    typedef forward_iterator_tag                       iterator_category;
+    typedef typename remove_const<
+                        typename __pointer_traits::element_type::value_type
+                     >::type                           value_type;
+    typedef typename __pointer_traits::difference_type difference_type;
+    typedef const value_type&                          reference;
+    typedef typename __pointer_traits::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<const value_type>
+#else
+            rebind<const value_type>::other
+#endif
+                                                       pointer;
+
+    _LIBCPP_INLINE_VISIBILITY __hash_const_local_iterator() _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __get_db()->__insert_i(this);
+#endif
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_const_local_iterator(const __non_const_iterator& __x) _NOEXCEPT
+        : __node_(__x.__node_),
+          __bucket_(__x.__bucket_),
+          __bucket_count_(__x.__bucket_count_)
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __get_db()->__iterator_copy(this, &__x);
+#endif
+    }
+
+#if _LIBCPP_DEBUG_LEVEL >= 2
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_const_local_iterator(const __hash_const_local_iterator& __i)
+        : __node_(__i.__node_),
+          __bucket_(__i.__bucket_),
+          __bucket_count_(__i.__bucket_count_)
+    {
+        __get_db()->__iterator_copy(this, &__i);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    ~__hash_const_local_iterator()
+    {
+        __get_db()->__erase_i(this);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_const_local_iterator& operator=(const __hash_const_local_iterator& __i)
+    {
+        if (this != &__i)
+        {
+            __get_db()->__iterator_copy(this, &__i);
+            __node_ = __i.__node_;
+            __bucket_ = __i.__bucket_;
+            __bucket_count_ = __i.__bucket_count_;
+        }
+        return *this;
+    }
+
+#endif  // _LIBCPP_DEBUG_LEVEL >= 2
+
+    _LIBCPP_INLINE_VISIBILITY
+        reference operator*() const
+        {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+            _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                           "Attempted to dereference a non-dereferenceable unordered container const_local_iterator");
+#endif
+            return __node_->__value_;
+        }
+    _LIBCPP_INLINE_VISIBILITY
+        pointer operator->() const
+        {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+            _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                           "Attempted to dereference a non-dereferenceable unordered container const_local_iterator");
+#endif
+            return pointer_traits<pointer>::pointer_to(__node_->__value_);
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_const_local_iterator& operator++()
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                       "Attempted to increment non-incrementable unordered container const_local_iterator");
+#endif
+        __node_ = __node_->__next_;
+        if (__node_ != nullptr && __constrain_hash(__node_->__hash_, __bucket_count_) != __bucket_)
+            __node_ = nullptr;
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_const_local_iterator operator++(int)
+    {
+        __hash_const_local_iterator __t(*this);
+        ++(*this);
+        return __t;
+    }
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator==(const __hash_const_local_iterator& __x, const __hash_const_local_iterator& __y)
+    {
+        return __x.__node_ == __y.__node_;
+    }
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(const __hash_const_local_iterator& __x, const __hash_const_local_iterator& __y)
+        {return !(__x == __y);}
+
+private:
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_const_local_iterator(__node_pointer __node, size_t __bucket,
+                                size_t __bucket_count, const void* __c) _NOEXCEPT
+        : __node_(__node),
+          __bucket_(__bucket),
+          __bucket_count_(__bucket_count)
+        {
+            __get_db()->__insert_ic(this, __c);
+            if (__node_ != nullptr)
+                __node_ = __node_->__next_;
+        }
+#else
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_const_local_iterator(__node_pointer __node, size_t __bucket,
+                                size_t __bucket_count) _NOEXCEPT
+        : __node_(__node),
+          __bucket_(__bucket),
+          __bucket_count_(__bucket_count)
+        {
+            if (__node_ != nullptr)
+                __node_ = __node_->__next_;
+        }
+#endif
+    template <class, class, class, class> friend class __hash_table;
+    template <class> friend class _LIBCPP_TYPE_VIS_ONLY __hash_map_const_iterator;
+};
+
+template <class _Alloc>
+class __bucket_list_deallocator
+{
+    typedef _Alloc                                          allocator_type;
+    typedef allocator_traits<allocator_type>                __alloc_traits;
+    typedef typename __alloc_traits::size_type              size_type;
+
+    __compressed_pair<size_type, allocator_type> __data_;
+public:
+    typedef typename __alloc_traits::pointer pointer;
+
+    _LIBCPP_INLINE_VISIBILITY
+    __bucket_list_deallocator()
+        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
+        : __data_(0) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __bucket_list_deallocator(const allocator_type& __a, size_type __size)
+        _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)
+        : __data_(__size, __a) {}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY
+    __bucket_list_deallocator(__bucket_list_deallocator&& __x)
+        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
+        : __data_(_VSTD::move(__x.__data_))
+    {
+        __x.size() = 0;
+    }
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type& size() _NOEXCEPT {return __data_.first();}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type  size() const _NOEXCEPT {return __data_.first();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    allocator_type& __alloc() _NOEXCEPT {return __data_.second();}
+    _LIBCPP_INLINE_VISIBILITY
+    const allocator_type& __alloc() const _NOEXCEPT {return __data_.second();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void operator()(pointer __p) _NOEXCEPT
+    {
+        __alloc_traits::deallocate(__alloc(), __p, size());
+    }
+};
+
+template <class _Alloc> class __hash_map_node_destructor;
+
+template <class _Alloc>
+class __hash_node_destructor
+{
+    typedef _Alloc                                          allocator_type;
+    typedef allocator_traits<allocator_type>                __alloc_traits;
+    typedef typename __alloc_traits::value_type::value_type value_type;
+public:
+    typedef typename __alloc_traits::pointer                pointer;
+private:
+
+    allocator_type& __na_;
+
+    __hash_node_destructor& operator=(const __hash_node_destructor&);
+
+public:
+    bool __value_constructed;
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __hash_node_destructor(allocator_type& __na,
+                                    bool __constructed = false) _NOEXCEPT
+        : __na_(__na),
+          __value_constructed(__constructed)
+        {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void operator()(pointer __p) _NOEXCEPT
+    {
+        if (__value_constructed)
+            __alloc_traits::destroy(__na_, _VSTD::addressof(__p->__value_));
+        if (__p)
+            __alloc_traits::deallocate(__na_, __p, 1);
+    }
+
+    template <class> friend class __hash_map_node_destructor;
+};
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+class __hash_table
+{
+public:
+    typedef _Tp    value_type;
+    typedef _Hash  hasher;
+    typedef _Equal key_equal;
+    typedef _Alloc allocator_type;
+
+private:
+    typedef allocator_traits<allocator_type> __alloc_traits;
+public:
+    typedef value_type&                              reference;
+    typedef const value_type&                        const_reference;
+    typedef typename __alloc_traits::pointer         pointer;
+    typedef typename __alloc_traits::const_pointer   const_pointer;
+    typedef typename __alloc_traits::size_type       size_type;
+    typedef typename __alloc_traits::difference_type difference_type;
+public:
+    // Create __node
+    typedef __hash_node<value_type, typename __alloc_traits::void_pointer> __node;
+    typedef typename __rebind_alloc_helper<__alloc_traits, __node>::type __node_allocator;
+    typedef allocator_traits<__node_allocator>       __node_traits;
+    typedef typename __node_traits::pointer          __node_pointer;
+    typedef typename __node_traits::pointer          __node_const_pointer;
+    typedef __hash_node_base<__node_pointer>         __first_node;
+    typedef typename pointer_traits<__node_pointer>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<__first_node>
+#else
+            rebind<__first_node>::other
+#endif
+                                                     __node_base_pointer;
+
+private:
+
+    typedef typename __rebind_alloc_helper<__node_traits, __node_pointer>::type __pointer_allocator;
+    typedef __bucket_list_deallocator<__pointer_allocator> __bucket_list_deleter;
+    typedef unique_ptr<__node_pointer[], __bucket_list_deleter> __bucket_list;
+    typedef allocator_traits<__pointer_allocator>          __pointer_alloc_traits;
+    typedef typename __bucket_list_deleter::pointer __node_pointer_pointer;
+
+    // --- Member data begin ---
+    __bucket_list                                     __bucket_list_;
+    __compressed_pair<__first_node, __node_allocator> __p1_;
+    __compressed_pair<size_type, hasher>              __p2_;
+    __compressed_pair<float, key_equal>               __p3_;
+    // --- Member data end ---
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type& size() _NOEXCEPT {return __p2_.first();}
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    size_type  size() const _NOEXCEPT {return __p2_.first();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    hasher& hash_function() _NOEXCEPT {return __p2_.second();}
+    _LIBCPP_INLINE_VISIBILITY
+    const hasher& hash_function() const _NOEXCEPT {return __p2_.second();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    float& max_load_factor() _NOEXCEPT {return __p3_.first();}
+    _LIBCPP_INLINE_VISIBILITY
+    float  max_load_factor() const _NOEXCEPT {return __p3_.first();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    key_equal& key_eq() _NOEXCEPT {return __p3_.second();}
+    _LIBCPP_INLINE_VISIBILITY
+    const key_equal& key_eq() const _NOEXCEPT {return __p3_.second();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __node_allocator& __node_alloc() _NOEXCEPT {return __p1_.second();}
+    _LIBCPP_INLINE_VISIBILITY
+    const __node_allocator& __node_alloc() const _NOEXCEPT
+        {return __p1_.second();}
+
+public:
+    typedef __hash_iterator<__node_pointer>                   iterator;
+    typedef __hash_const_iterator<__node_pointer>             const_iterator;
+    typedef __hash_local_iterator<__node_pointer>             local_iterator;
+    typedef __hash_const_local_iterator<__node_pointer>       const_local_iterator;
+
+    __hash_table()
+        _NOEXCEPT_(
+            is_nothrow_default_constructible<__bucket_list>::value &&
+            is_nothrow_default_constructible<__first_node>::value &&
+            is_nothrow_default_constructible<__node_allocator>::value &&
+            is_nothrow_default_constructible<hasher>::value &&
+            is_nothrow_default_constructible<key_equal>::value);
+    __hash_table(const hasher& __hf, const key_equal& __eql);
+    __hash_table(const hasher& __hf, const key_equal& __eql,
+                 const allocator_type& __a);
+    explicit __hash_table(const allocator_type& __a);
+    __hash_table(const __hash_table& __u);
+    __hash_table(const __hash_table& __u, const allocator_type& __a);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    __hash_table(__hash_table&& __u)
+        _NOEXCEPT_(
+            is_nothrow_move_constructible<__bucket_list>::value &&
+            is_nothrow_move_constructible<__first_node>::value &&
+            is_nothrow_move_constructible<__node_allocator>::value &&
+            is_nothrow_move_constructible<hasher>::value &&
+            is_nothrow_move_constructible<key_equal>::value);
+    __hash_table(__hash_table&& __u, const allocator_type& __a);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    ~__hash_table();
+
+    __hash_table& operator=(const __hash_table& __u);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    __hash_table& operator=(__hash_table&& __u)
+        _NOEXCEPT_(
+            __node_traits::propagate_on_container_move_assignment::value &&
+            is_nothrow_move_assignable<__node_allocator>::value &&
+            is_nothrow_move_assignable<hasher>::value &&
+            is_nothrow_move_assignable<key_equal>::value);
+#endif
+    template <class _InputIterator>
+        void __assign_unique(_InputIterator __first, _InputIterator __last);
+    template <class _InputIterator>
+        void __assign_multi(_InputIterator __first, _InputIterator __last);
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type max_size() const _NOEXCEPT
+    {
+        return allocator_traits<__pointer_allocator>::max_size(
+            __bucket_list_.get_deleter().__alloc());
+    }
+
+    pair<iterator, bool> __node_insert_unique(__node_pointer __nd);
+    iterator             __node_insert_multi(__node_pointer __nd);
+    iterator             __node_insert_multi(const_iterator __p,
+                                             __node_pointer __nd);
+
+#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+    template <class... _Args>
+        pair<iterator, bool> __emplace_unique(_Args&&... __args);
+    template <class... _Args>
+        iterator __emplace_multi(_Args&&... __args);
+    template <class... _Args>
+        iterator __emplace_hint_multi(const_iterator __p, _Args&&... __args);
+#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template <class _ValueTp>
+    _LIBCPP_INLINE_VISIBILITY
+    pair<iterator, bool> __insert_unique_value(_ValueTp&& __x);
+#else
+    _LIBCPP_INLINE_VISIBILITY
+    pair<iterator, bool> __insert_unique_value(const value_type& __x);
+#endif
+
+    pair<iterator, bool> __insert_unique(const value_type& __x);
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    pair<iterator, bool> __insert_unique(value_type&& __x);
+    template <class _Pp>
+    pair<iterator, bool> __insert_unique(_Pp&& __x);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template <class _Pp>
+        iterator __insert_multi(_Pp&& __x);
+    template <class _Pp>
+        iterator __insert_multi(const_iterator __p, _Pp&& __x);
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    iterator __insert_multi(const value_type& __x);
+    iterator __insert_multi(const_iterator __p, const value_type& __x);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    void clear() _NOEXCEPT;
+    void rehash(size_type __n);
+    _LIBCPP_INLINE_VISIBILITY void reserve(size_type __n)
+        {rehash(static_cast<size_type>(ceil(__n / max_load_factor())));}
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type bucket_count() const _NOEXCEPT
+    {
+        return __bucket_list_.get_deleter().size();
+    }
+
+    iterator       begin() _NOEXCEPT;
+    iterator       end() _NOEXCEPT;
+    const_iterator begin() const _NOEXCEPT;
+    const_iterator end() const _NOEXCEPT;
+
+    template <class _Key>
+        _LIBCPP_INLINE_VISIBILITY
+        size_type bucket(const _Key& __k) const
+        {
+            _LIBCPP_ASSERT(bucket_count() > 0,
+                "unordered container::bucket(key) called when bucket_count() == 0");
+            return __constrain_hash(hash_function()(__k), bucket_count());
+        }
+
+    template <class _Key>
+        iterator       find(const _Key& __x);
+    template <class _Key>
+        const_iterator find(const _Key& __x) const;
+
+    typedef __hash_node_destructor<__node_allocator> _Dp;
+    typedef unique_ptr<__node, _Dp> __node_holder;
+
+    iterator erase(const_iterator __p);
+    iterator erase(const_iterator __first, const_iterator __last);
+    template <class _Key>
+        size_type __erase_unique(const _Key& __k);
+    template <class _Key>
+        size_type __erase_multi(const _Key& __k);
+    __node_holder remove(const_iterator __p) _NOEXCEPT;
+
+    template <class _Key>
+        size_type __count_unique(const _Key& __k) const;
+    template <class _Key>
+        size_type __count_multi(const _Key& __k) const;
+
+    template <class _Key>
+        pair<iterator, iterator>
+        __equal_range_unique(const _Key& __k);
+    template <class _Key>
+        pair<const_iterator, const_iterator>
+        __equal_range_unique(const _Key& __k) const;
+
+    template <class _Key>
+        pair<iterator, iterator>
+        __equal_range_multi(const _Key& __k);
+    template <class _Key>
+        pair<const_iterator, const_iterator>
+        __equal_range_multi(const _Key& __k) const;
+
+    void swap(__hash_table& __u)
+#if _LIBCPP_STD_VER <= 11
+        _NOEXCEPT_(
+            __is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value
+            && (!allocator_traits<__pointer_allocator>::propagate_on_container_swap::value
+                  || __is_nothrow_swappable<__pointer_allocator>::value)
+            && (!__node_traits::propagate_on_container_swap::value
+                  || __is_nothrow_swappable<__node_allocator>::value)
+            );
+#else
+     _NOEXCEPT_(__is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value);
+#endif
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type max_bucket_count() const _NOEXCEPT
+        {return __pointer_alloc_traits::max_size(__bucket_list_.get_deleter().__alloc());}
+    size_type bucket_size(size_type __n) const;
+    _LIBCPP_INLINE_VISIBILITY float load_factor() const _NOEXCEPT
+    {
+        size_type __bc = bucket_count();
+        return __bc != 0 ? (float)size() / __bc : 0.f;
+    }
+    _LIBCPP_INLINE_VISIBILITY void max_load_factor(float __mlf) _NOEXCEPT
+    {
+        _LIBCPP_ASSERT(__mlf > 0,
+            "unordered container::max_load_factor(lf) called with lf <= 0");
+        max_load_factor() = _VSTD::max(__mlf, load_factor());
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    local_iterator
+    begin(size_type __n)
+    {
+        _LIBCPP_ASSERT(__n < bucket_count(),
+            "unordered container::begin(n) called with n >= bucket_count()");
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        return local_iterator(__bucket_list_[__n], __n, bucket_count(), this);
+#else
+        return local_iterator(__bucket_list_[__n], __n, bucket_count());
+#endif
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    local_iterator
+    end(size_type __n)
+    {
+        _LIBCPP_ASSERT(__n < bucket_count(),
+            "unordered container::end(n) called with n >= bucket_count()");
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        return local_iterator(nullptr, __n, bucket_count(), this);
+#else
+        return local_iterator(nullptr, __n, bucket_count());
+#endif
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    const_local_iterator
+    cbegin(size_type __n) const
+    {
+        _LIBCPP_ASSERT(__n < bucket_count(),
+            "unordered container::cbegin(n) called with n >= bucket_count()");
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        return const_local_iterator(__bucket_list_[__n], __n, bucket_count(), this);
+#else
+        return const_local_iterator(__bucket_list_[__n], __n, bucket_count());
+#endif
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    const_local_iterator
+    cend(size_type __n) const
+    {
+        _LIBCPP_ASSERT(__n < bucket_count(),
+            "unordered container::cend(n) called with n >= bucket_count()");
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        return const_local_iterator(nullptr, __n, bucket_count(), this);
+#else
+        return const_local_iterator(nullptr, __n, bucket_count());
+#endif
+    }
+
+#if _LIBCPP_DEBUG_LEVEL >= 2
+
+    bool __dereferenceable(const const_iterator* __i) const;
+    bool __decrementable(const const_iterator* __i) const;
+    bool __addable(const const_iterator* __i, ptrdiff_t __n) const;
+    bool __subscriptable(const const_iterator* __i, ptrdiff_t __n) const;
+
+#endif  // _LIBCPP_DEBUG_LEVEL >= 2
+
+private:
+    void __rehash(size_type __n);
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    template <class ..._Args>
+        __node_holder __construct_node(_Args&& ...__args);
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+    __node_holder __construct_node(value_type&& __v, size_t __hash);
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    __node_holder __construct_node(const value_type& __v);
+#endif
+    __node_holder __construct_node(const value_type& __v, size_t __hash);
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __copy_assign_alloc(const __hash_table& __u)
+        {__copy_assign_alloc(__u, integral_constant<bool,
+             __node_traits::propagate_on_container_copy_assignment::value>());}
+    void __copy_assign_alloc(const __hash_table& __u, true_type);
+    _LIBCPP_INLINE_VISIBILITY
+        void __copy_assign_alloc(const __hash_table&, false_type) {}
+
+    void __move_assign(__hash_table& __u, false_type);
+    void __move_assign(__hash_table& __u, true_type)
+        _NOEXCEPT_(
+            is_nothrow_move_assignable<__node_allocator>::value &&
+            is_nothrow_move_assignable<hasher>::value &&
+            is_nothrow_move_assignable<key_equal>::value);
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__hash_table& __u)
+        _NOEXCEPT_(
+            !__node_traits::propagate_on_container_move_assignment::value ||
+            (is_nothrow_move_assignable<__pointer_allocator>::value &&
+             is_nothrow_move_assignable<__node_allocator>::value))
+        {__move_assign_alloc(__u, integral_constant<bool,
+             __node_traits::propagate_on_container_move_assignment::value>());}
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__hash_table& __u, true_type)
+        _NOEXCEPT_(
+            is_nothrow_move_assignable<__pointer_allocator>::value &&
+            is_nothrow_move_assignable<__node_allocator>::value)
+    {
+        __bucket_list_.get_deleter().__alloc() =
+                _VSTD::move(__u.__bucket_list_.get_deleter().__alloc());
+        __node_alloc() = _VSTD::move(__u.__node_alloc());
+    }
+    _LIBCPP_INLINE_VISIBILITY
+        void __move_assign_alloc(__hash_table&, false_type) _NOEXCEPT {}
+
+    void __deallocate(__node_pointer __np) _NOEXCEPT;
+    __node_pointer __detach() _NOEXCEPT;
+
+    template <class, class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY unordered_map;
+    template <class, class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY unordered_multimap;
+};
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table()
+    _NOEXCEPT_(
+        is_nothrow_default_constructible<__bucket_list>::value &&
+        is_nothrow_default_constructible<__first_node>::value &&
+        is_nothrow_default_constructible<hasher>::value &&
+        is_nothrow_default_constructible<key_equal>::value)
+    : __p2_(0),
+      __p3_(1.0f)
+{
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const hasher& __hf,
+                                                       const key_equal& __eql)
+    : __bucket_list_(nullptr, __bucket_list_deleter()),
+      __p1_(),
+      __p2_(0, __hf),
+      __p3_(1.0f, __eql)
+{
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const hasher& __hf,
+                                                       const key_equal& __eql,
+                                                       const allocator_type& __a)
+    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
+      __p1_(__node_allocator(__a)),
+      __p2_(0, __hf),
+      __p3_(1.0f, __eql)
+{
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const allocator_type& __a)
+    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
+      __p1_(__node_allocator(__a)),
+      __p2_(0),
+      __p3_(1.0f)
+{
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const __hash_table& __u)
+    : __bucket_list_(nullptr,
+          __bucket_list_deleter(allocator_traits<__pointer_allocator>::
+              select_on_container_copy_construction(
+                  __u.__bucket_list_.get_deleter().__alloc()), 0)),
+      __p1_(allocator_traits<__node_allocator>::
+          select_on_container_copy_construction(__u.__node_alloc())),
+      __p2_(0, __u.hash_function()),
+      __p3_(__u.__p3_)
+{
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const __hash_table& __u,
+                                                       const allocator_type& __a)
+    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
+      __p1_(__node_allocator(__a)),
+      __p2_(0, __u.hash_function()),
+      __p3_(__u.__p3_)
+{
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(__hash_table&& __u)
+        _NOEXCEPT_(
+            is_nothrow_move_constructible<__bucket_list>::value &&
+            is_nothrow_move_constructible<__first_node>::value &&
+            is_nothrow_move_constructible<hasher>::value &&
+            is_nothrow_move_constructible<key_equal>::value)
+    : __bucket_list_(_VSTD::move(__u.__bucket_list_)),
+      __p1_(_VSTD::move(__u.__p1_)),
+      __p2_(_VSTD::move(__u.__p2_)),
+      __p3_(_VSTD::move(__u.__p3_))
+{
+    if (size() > 0)
+    {
+        __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash_, bucket_count())] =
+            static_cast<__node_pointer>(pointer_traits<__node_base_pointer>::pointer_to(__p1_.first()));
+        __u.__p1_.first().__next_ = nullptr;
+        __u.size() = 0;
+    }
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(__hash_table&& __u,
+                                                       const allocator_type& __a)
+    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
+      __p1_(__node_allocator(__a)),
+      __p2_(0, _VSTD::move(__u.hash_function())),
+      __p3_(_VSTD::move(__u.__p3_))
+{
+    if (__a == allocator_type(__u.__node_alloc()))
+    {
+        __bucket_list_.reset(__u.__bucket_list_.release());
+        __bucket_list_.get_deleter().size() = __u.__bucket_list_.get_deleter().size();
+        __u.__bucket_list_.get_deleter().size() = 0;
+        if (__u.size() > 0)
+        {
+            __p1_.first().__next_ = __u.__p1_.first().__next_;
+            __u.__p1_.first().__next_ = nullptr;
+            __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash_, bucket_count())] =
+                static_cast<__node_pointer>(pointer_traits<__node_base_pointer>::pointer_to(__p1_.first()));
+            size() = __u.size();
+            __u.size() = 0;
+        }
+    }
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::~__hash_table()
+{
+    __deallocate(__p1_.first().__next_);
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->__erase_c(this);
+#endif
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+void
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__copy_assign_alloc(
+        const __hash_table& __u, true_type)
+{
+    if (__node_alloc() != __u.__node_alloc())
+    {
+        clear();
+        __bucket_list_.reset();
+        __bucket_list_.get_deleter().size() = 0;
+    }
+    __bucket_list_.get_deleter().__alloc() = __u.__bucket_list_.get_deleter().__alloc();
+    __node_alloc() = __u.__node_alloc();
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>&
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::operator=(const __hash_table& __u)
+{
+    if (this != &__u)
+    {
+        __copy_assign_alloc(__u);
+        hash_function() = __u.hash_function();
+        key_eq() = __u.key_eq();
+        max_load_factor() = __u.max_load_factor();
+        __assign_multi(__u.begin(), __u.end());
+    }
+    return *this;
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+void
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__deallocate(__node_pointer __np)
+    _NOEXCEPT
+{
+    __node_allocator& __na = __node_alloc();
+    while (__np != nullptr)
+    {
+        __node_pointer __next = __np->__next_;
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __c_node* __c = __get_db()->__find_c_and_lock(this);
+        for (__i_node** __p = __c->end_; __p != __c->beg_; )
+        {
+            --__p;
+            iterator* __i = static_cast<iterator*>((*__p)->__i_);
+            if (__i->__node_ == __np)
+            {
+                (*__p)->__c_ = nullptr;
+                if (--__c->end_ != __p)
+                    memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
+            }
+        }
+        __get_db()->unlock();
+#endif
+        __node_traits::destroy(__na, _VSTD::addressof(__np->__value_));
+        __node_traits::deallocate(__na, __np, 1);
+        __np = __next;
+    }
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_pointer
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__detach() _NOEXCEPT
+{
+    size_type __bc = bucket_count();
+    for (size_type __i = 0; __i < __bc; ++__i)
+        __bucket_list_[__i] = nullptr;
+    size() = 0;
+    __node_pointer __cache = __p1_.first().__next_;
+    __p1_.first().__next_ = nullptr;
+    return __cache;
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+void
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__move_assign(
+        __hash_table& __u, true_type)
+    _NOEXCEPT_(
+        is_nothrow_move_assignable<__node_allocator>::value &&
+        is_nothrow_move_assignable<hasher>::value &&
+        is_nothrow_move_assignable<key_equal>::value)
+{
+    clear();
+    __bucket_list_.reset(__u.__bucket_list_.release());
+    __bucket_list_.get_deleter().size() = __u.__bucket_list_.get_deleter().size();
+    __u.__bucket_list_.get_deleter().size() = 0;
+    __move_assign_alloc(__u);
+    size() = __u.size();
+    hash_function() = _VSTD::move(__u.hash_function());
+    max_load_factor() = __u.max_load_factor();
+    key_eq() = _VSTD::move(__u.key_eq());
+    __p1_.first().__next_ = __u.__p1_.first().__next_;
+    if (size() > 0)
+    {
+        __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash_, bucket_count())] =
+            static_cast<__node_pointer>(pointer_traits<__node_base_pointer>::pointer_to(__p1_.first()));
+        __u.__p1_.first().__next_ = nullptr;
+        __u.size() = 0;
+    }
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->swap(this, &__u);
+#endif
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+void
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__move_assign(
+        __hash_table& __u, false_type)
+{
+    if (__node_alloc() == __u.__node_alloc())
+        __move_assign(__u, true_type());
+    else
+    {
+        hash_function() = _VSTD::move(__u.hash_function());
+        key_eq() = _VSTD::move(__u.key_eq());
+        max_load_factor() = __u.max_load_factor();
+        if (bucket_count() != 0)
+        {
+            __node_pointer __cache = __detach();
+#ifndef _LIBCPP_NO_EXCEPTIONS
+            try
+            {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+                const_iterator __i = __u.begin();
+                while (__cache != nullptr && __u.size() != 0)
+                {
+                    __cache->__value_ = _VSTD::move(__u.remove(__i++)->__value_);
+                    __node_pointer __next = __cache->__next_;
+                    __node_insert_multi(__cache);
+                    __cache = __next;
+                }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+            }
+            catch (...)
+            {
+                __deallocate(__cache);
+                throw;
+            }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            __deallocate(__cache);
+        }
+        const_iterator __i = __u.begin();
+        while (__u.size() != 0)
+        {
+            __node_holder __h =
+                    __construct_node(_VSTD::move(__u.remove(__i++)->__value_));
+            __node_insert_multi(__h.get());
+            __h.release();
+        }
+    }
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+__hash_table<_Tp, _Hash, _Equal, _Alloc>&
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::operator=(__hash_table&& __u)
+    _NOEXCEPT_(
+        __node_traits::propagate_on_container_move_assignment::value &&
+        is_nothrow_move_assignable<__node_allocator>::value &&
+        is_nothrow_move_assignable<hasher>::value &&
+        is_nothrow_move_assignable<key_equal>::value)
+{
+    __move_assign(__u, integral_constant<bool,
+                  __node_traits::propagate_on_container_move_assignment::value>());
+    return *this;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class _InputIterator>
+void
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__assign_unique(_InputIterator __first,
+                                                          _InputIterator __last)
+{
+    if (bucket_count() != 0)
+    {
+        __node_pointer __cache = __detach();
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        try
+        {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            for (; __cache != nullptr && __first != __last; ++__first)
+            {
+                __cache->__value_ = *__first;
+                __node_pointer __next = __cache->__next_;
+                __node_insert_unique(__cache);
+                __cache = __next;
+            }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        }
+        catch (...)
+        {
+            __deallocate(__cache);
+            throw;
+        }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        __deallocate(__cache);
+    }
+    for (; __first != __last; ++__first)
+        __insert_unique(*__first);
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class _InputIterator>
+void
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__assign_multi(_InputIterator __first,
+                                                         _InputIterator __last)
+{
+    if (bucket_count() != 0)
+    {
+        __node_pointer __cache = __detach();
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        try
+        {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            for (; __cache != nullptr && __first != __last; ++__first)
+            {
+                __cache->__value_ = *__first;
+                __node_pointer __next = __cache->__next_;
+                __node_insert_multi(__cache);
+                __cache = __next;
+            }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        }
+        catch (...)
+        {
+            __deallocate(__cache);
+            throw;
+        }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        __deallocate(__cache);
+    }
+    for (; __first != __last; ++__first)
+        __insert_multi(*__first);
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::begin() _NOEXCEPT
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    return iterator(__p1_.first().__next_, this);
+#else
+    return iterator(__p1_.first().__next_);
+#endif
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::end() _NOEXCEPT
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    return iterator(nullptr, this);
+#else
+    return iterator(nullptr);
+#endif
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::begin() const _NOEXCEPT
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    return const_iterator(__p1_.first().__next_, this);
+#else
+    return const_iterator(__p1_.first().__next_);
+#endif
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::end() const _NOEXCEPT
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    return const_iterator(nullptr, this);
+#else
+    return const_iterator(nullptr);
+#endif
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+void
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::clear() _NOEXCEPT
+{
+    if (size() > 0)
+    {
+        __deallocate(__p1_.first().__next_);
+        __p1_.first().__next_ = nullptr;
+        size_type __bc = bucket_count();
+        for (size_type __i = 0; __i < __bc; ++__i)
+            __bucket_list_[__i] = nullptr;
+        size() = 0;
+    }
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_unique(__node_pointer __nd)
+{
+    __nd->__hash_ = hash_function()(__nd->__value_);
+    size_type __bc = bucket_count();
+    bool __inserted = false;
+    __node_pointer __ndptr;
+    size_t __chash;
+    if (__bc != 0)
+    {
+        __chash = __constrain_hash(__nd->__hash_, __bc);
+        __ndptr = __bucket_list_[__chash];
+        if (__ndptr != nullptr)
+        {
+            for (__ndptr = __ndptr->__next_; __ndptr != nullptr &&
+                                             __constrain_hash(__ndptr->__hash_, __bc) == __chash;
+                                                     __ndptr = __ndptr->__next_)
+            {
+                if (key_eq()(__ndptr->__value_, __nd->__value_))
+                    goto __done;
+            }
+        }
+    }
+    {
+        if (size()+1 > __bc * max_load_factor() || __bc == 0)
+        {
+            rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
+                           size_type(ceil(float(size() + 1) / max_load_factor()))));
+            __bc = bucket_count();
+            __chash = __constrain_hash(__nd->__hash_, __bc);
+        }
+        // insert_after __bucket_list_[__chash], or __first_node if bucket is null
+        __node_pointer __pn = __bucket_list_[__chash];
+        if (__pn == nullptr)
+        {
+            __pn = static_cast<__node_pointer>(pointer_traits<__node_base_pointer>::pointer_to(__p1_.first()));
+            __nd->__next_ = __pn->__next_;
+            __pn->__next_ = __nd;
+            // fix up __bucket_list_
+            __bucket_list_[__chash] = __pn;
+            if (__nd->__next_ != nullptr)
+                __bucket_list_[__constrain_hash(__nd->__next_->__hash_, __bc)] = __nd;
+        }
+        else
+        {
+            __nd->__next_ = __pn->__next_;
+            __pn->__next_ = __nd;
+        }
+        __ndptr = __nd;
+        // increment size
+        ++size();
+        __inserted = true;
+    }
+__done:
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    return pair<iterator, bool>(iterator(__ndptr, this), __inserted);
+#else
+    return pair<iterator, bool>(iterator(__ndptr), __inserted);
+#endif
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi(__node_pointer __cp)
+{
+    __cp->__hash_ = hash_function()(__cp->__value_);
+    size_type __bc = bucket_count();
+    if (size()+1 > __bc * max_load_factor() || __bc == 0)
+    {
+        rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
+                       size_type(ceil(float(size() + 1) / max_load_factor()))));
+        __bc = bucket_count();
+    }
+    size_t __chash = __constrain_hash(__cp->__hash_, __bc);
+    __node_pointer __pn = __bucket_list_[__chash];
+    if (__pn == nullptr)
+    {
+        __pn = static_cast<__node_pointer>(pointer_traits<__node_base_pointer>::pointer_to(__p1_.first()));
+        __cp->__next_ = __pn->__next_;
+        __pn->__next_ = __cp;
+        // fix up __bucket_list_
+        __bucket_list_[__chash] = __pn;
+        if (__cp->__next_ != nullptr)
+            __bucket_list_[__constrain_hash(__cp->__next_->__hash_, __bc)] = __cp;
+    }
+    else
+    {
+        for (bool __found = false; __pn->__next_ != nullptr &&
+                                   __constrain_hash(__pn->__next_->__hash_, __bc) == __chash;
+                                                           __pn = __pn->__next_)
+        {
+            //      __found    key_eq()     action
+            //      false       false       loop
+            //      true        true        loop
+            //      false       true        set __found to true
+            //      true        false       break
+            if (__found != (__pn->__next_->__hash_ == __cp->__hash_ &&
+                            key_eq()(__pn->__next_->__value_, __cp->__value_)))
+            {
+                if (!__found)
+                    __found = true;
+                else
+                    break;
+            }
+        }
+        __cp->__next_ = __pn->__next_;
+        __pn->__next_ = __cp;
+        if (__cp->__next_ != nullptr)
+        {
+            size_t __nhash = __constrain_hash(__cp->__next_->__hash_, __bc);
+            if (__nhash != __chash)
+                __bucket_list_[__nhash] = __cp;
+        }
+    }
+    ++size();
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    return iterator(__cp, this);
+#else
+    return iterator(__cp);
+#endif
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi(
+        const_iterator __p, __node_pointer __cp)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
+        "unordered container::emplace_hint(const_iterator, args...) called with an iterator not"
+        " referring to this unordered container");
+#endif
+    if (__p != end() && key_eq()(*__p, __cp->__value_))
+    {
+        __node_pointer __np = __p.__node_;
+        __cp->__hash_ = __np->__hash_;
+        size_type __bc = bucket_count();
+        if (size()+1 > __bc * max_load_factor() || __bc == 0)
+        {
+            rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
+                           size_type(ceil(float(size() + 1) / max_load_factor()))));
+            __bc = bucket_count();
+        }
+        size_t __chash = __constrain_hash(__cp->__hash_, __bc);
+        __node_pointer __pp = __bucket_list_[__chash];
+        while (__pp->__next_ != __np)
+            __pp = __pp->__next_;
+        __cp->__next_ = __np;
+        __pp->__next_ = __cp;
+        ++size();
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        return iterator(__cp, this);
+#else
+        return iterator(__cp);
+#endif
+    }
+    return __node_insert_multi(__cp);
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__insert_unique(const value_type& __x)
+{
+    return __insert_unique_value(__x);
+}
+
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class _ValueTp>
+_LIBCPP_INLINE_VISIBILITY
+pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__insert_unique_value(_ValueTp&& __x)
+#else
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+_LIBCPP_INLINE_VISIBILITY
+pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__insert_unique_value(const value_type& __x)
+#endif
+{
+#if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+    typedef const value_type& _ValueTp;
+#endif
+    size_t __hash = hash_function()(__x);
+    size_type __bc = bucket_count();
+    bool __inserted = false;
+    __node_pointer __nd;
+    size_t __chash;
+    if (__bc != 0)
+    {
+        __chash = __constrain_hash(__hash, __bc);
+        __nd = __bucket_list_[__chash];
+        if (__nd != nullptr)
+        {
+            for (__nd = __nd->__next_; __nd != nullptr &&
+                                       __constrain_hash(__nd->__hash_, __bc) == __chash;
+                                                           __nd = __nd->__next_)
+            {
+                if (key_eq()(__nd->__value_, __x))
+                    goto __done;
+            }
+        }
+    }
+    {
+        __node_holder __h = __construct_node(_VSTD::forward<_ValueTp>(__x), __hash);
+        if (size()+1 > __bc * max_load_factor() || __bc == 0)
+        {
+            rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
+                           size_type(ceil(float(size() + 1) / max_load_factor()))));
+            __bc = bucket_count();
+            __chash = __constrain_hash(__hash, __bc);
+        }
+        // insert_after __bucket_list_[__chash], or __first_node if bucket is null
+        __node_pointer __pn = __bucket_list_[__chash];
+        if (__pn == nullptr)
+        {
+            __pn = static_cast<__node_pointer>(pointer_traits<__node_base_pointer>::pointer_to(__p1_.first()));
+            __h->__next_ = __pn->__next_;
+            __pn->__next_ = __h.get();
+            // fix up __bucket_list_
+            __bucket_list_[__chash] = __pn;
+            if (__h->__next_ != nullptr)
+                __bucket_list_[__constrain_hash(__h->__next_->__hash_, __bc)] = __h.get();
+        }
+        else
+        {
+            __h->__next_ = __pn->__next_;
+            __pn->__next_ = __h.get();
+        }
+        __nd = __h.release();
+        // increment size
+        ++size();
+        __inserted = true;
+    }
+__done:
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    return pair<iterator, bool>(iterator(__nd, this), __inserted);
+#else
+    return pair<iterator, bool>(iterator(__nd), __inserted);
+#endif
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class... _Args>
+pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_unique(_Args&&... __args)
+{
+    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
+    pair<iterator, bool> __r = __node_insert_unique(__h.get());
+    if (__r.second)
+        __h.release();
+    return __r;
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class... _Args>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_multi(_Args&&... __args)
+{
+    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
+    iterator __r = __node_insert_multi(__h.get());
+    __h.release();
+    return __r;
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class... _Args>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_hint_multi(
+        const_iterator __p, _Args&&... __args)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
+        "unordered container::emplace_hint(const_iterator, args...) called with an iterator not"
+        " referring to this unordered container");
+#endif
+    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
+    iterator __r = __node_insert_multi(__p, __h.get());
+    __h.release();
+    return __r;
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__insert_unique(value_type&& __x)
+{
+    return __insert_unique_value(_VSTD::move(__x));
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class _Pp>
+pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__insert_unique(_Pp&& __x)
+{
+    __node_holder __h = __construct_node(_VSTD::forward<_Pp>(__x));
+    pair<iterator, bool> __r = __node_insert_unique(__h.get());
+    if (__r.second)
+        __h.release();
+    return __r;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class _Pp>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__insert_multi(_Pp&& __x)
+{
+    __node_holder __h = __construct_node(_VSTD::forward<_Pp>(__x));
+    iterator __r = __node_insert_multi(__h.get());
+    __h.release();
+    return __r;
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class _Pp>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__insert_multi(const_iterator __p,
+                                                         _Pp&& __x)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
+        "unordered container::insert(const_iterator, rvalue) called with an iterator not"
+        " referring to this unordered container");
+#endif
+    __node_holder __h = __construct_node(_VSTD::forward<_Pp>(__x));
+    iterator __r = __node_insert_multi(__p, __h.get());
+    __h.release();
+    return __r;
+}
+
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__insert_multi(const value_type& __x)
+{
+    __node_holder __h = __construct_node(__x);
+    iterator __r = __node_insert_multi(__h.get());
+    __h.release();
+    return __r;
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__insert_multi(const_iterator __p,
+                                                         const value_type& __x)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
+        "unordered container::insert(const_iterator, lvalue) called with an iterator not"
+        " referring to this unordered container");
+#endif
+    __node_holder __h = __construct_node(__x);
+    iterator __r = __node_insert_multi(__p, __h.get());
+    __h.release();
+    return __r;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+void
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::rehash(size_type __n)
+{
+    if (__n == 1)
+        __n = 2;
+    else if (__n & (__n - 1))
+        __n = __next_prime(__n);
+    size_type __bc = bucket_count();
+    if (__n > __bc)
+        __rehash(__n);
+    else if (__n < __bc)
+    {
+        __n = _VSTD::max<size_type>
+              (
+                  __n,
+                  __is_hash_power2(__bc) ? __next_hash_pow2(size_t(ceil(float(size()) / max_load_factor()))) :
+                                           __next_prime(size_t(ceil(float(size()) / max_load_factor())))
+              );
+        if (__n < __bc)
+            __rehash(__n);
+    }
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+void
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__rehash(size_type __nbc)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->__invalidate_all(this);
+#endif  // _LIBCPP_DEBUG_LEVEL >= 2
+    __pointer_allocator& __npa = __bucket_list_.get_deleter().__alloc();
+    __bucket_list_.reset(__nbc > 0 ?
+                      __pointer_alloc_traits::allocate(__npa, __nbc) : nullptr);
+    __bucket_list_.get_deleter().size() = __nbc;
+    if (__nbc > 0)
+    {
+        for (size_type __i = 0; __i < __nbc; ++__i)
+            __bucket_list_[__i] = nullptr;
+        __node_pointer __pp(static_cast<__node_pointer>(pointer_traits<__node_base_pointer>::pointer_to(__p1_.first())));
+        __node_pointer __cp = __pp->__next_;
+        if (__cp != nullptr)
+        {
+            size_type __chash = __constrain_hash(__cp->__hash_, __nbc);
+            __bucket_list_[__chash] = __pp;
+            size_type __phash = __chash;
+            for (__pp = __cp, __cp = __cp->__next_; __cp != nullptr;
+                                                           __cp = __pp->__next_)
+            {
+                __chash = __constrain_hash(__cp->__hash_, __nbc);
+                if (__chash == __phash)
+                    __pp = __cp;
+                else
+                {
+                    if (__bucket_list_[__chash] == nullptr)
+                    {
+                        __bucket_list_[__chash] = __pp;
+                        __pp = __cp;
+                        __phash = __chash;
+                    }
+                    else
+                    {
+                        __node_pointer __np = __cp;
+                        for (; __np->__next_ != nullptr &&
+                               key_eq()(__cp->__value_, __np->__next_->__value_);
+                                                           __np = __np->__next_)
+                            ;
+                        __pp->__next_ = __np->__next_;
+                        __np->__next_ = __bucket_list_[__chash]->__next_;
+                        __bucket_list_[__chash]->__next_ = __cp;
+
+                    }
+                }
+            }
+        }
+    }
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class _Key>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::find(const _Key& __k)
+{
+    size_t __hash = hash_function()(__k);
+    size_type __bc = bucket_count();
+    if (__bc != 0)
+    {
+        size_t __chash = __constrain_hash(__hash, __bc);
+        __node_pointer __nd = __bucket_list_[__chash];
+        if (__nd != nullptr)
+        {
+            for (__nd = __nd->__next_; __nd != nullptr &&
+                                       __constrain_hash(__nd->__hash_, __bc) == __chash;
+                                                           __nd = __nd->__next_)
+            {
+                if (key_eq()(__nd->__value_, __k))
+#if _LIBCPP_DEBUG_LEVEL >= 2
+                    return iterator(__nd, this);
+#else
+                    return iterator(__nd);
+#endif
+            }
+        }
+    }
+    return end();
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class _Key>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::find(const _Key& __k) const
+{
+    size_t __hash = hash_function()(__k);
+    size_type __bc = bucket_count();
+    if (__bc != 0)
+    {
+        size_t __chash = __constrain_hash(__hash, __bc);
+        __node_const_pointer __nd = __bucket_list_[__chash];
+        if (__nd != nullptr)
+        {
+            for (__nd = __nd->__next_; __nd != nullptr &&
+                                           __constrain_hash(__nd->__hash_, __bc) == __chash;
+                                                           __nd = __nd->__next_)
+            {
+                if (key_eq()(__nd->__value_, __k))
+#if _LIBCPP_DEBUG_LEVEL >= 2
+                    return const_iterator(__nd, this);
+#else
+                    return const_iterator(__nd);
+#endif
+            }
+        }
+
+    }
+    return end();
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class ..._Args>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node(_Args&& ...__args)
+{
+    __node_allocator& __na = __node_alloc();
+    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_), _VSTD::forward<_Args>(__args)...);
+    __h.get_deleter().__value_constructed = true;
+    __h->__hash_ = hash_function()(__h->__value_);
+    __h->__next_ = nullptr;
+    return __h;
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node(value_type&& __v,
+                                                           size_t __hash)
+{
+    __node_allocator& __na = __node_alloc();
+    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_), _VSTD::move(__v));
+    __h.get_deleter().__value_constructed = true;
+    __h->__hash_ = __hash;
+    __h->__next_ = nullptr;
+    return __h;
+}
+
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node(const value_type& __v)
+{
+    __node_allocator& __na = __node_alloc();
+    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_), __v);
+    __h.get_deleter().__value_constructed = true;
+    __h->__hash_ = hash_function()(__h->__value_);
+    __h->__next_ = nullptr;
+    return _VSTD::move(__h);  // explicitly moved for C++03
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node(const value_type& __v,
+                                                           size_t __hash)
+{
+    __node_allocator& __na = __node_alloc();
+    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_), __v);
+    __h.get_deleter().__value_constructed = true;
+    __h->__hash_ = __hash;
+    __h->__next_ = nullptr;
+    return _VSTD::move(__h);  // explicitly moved for C++03
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::erase(const_iterator __p)
+{
+    __node_pointer __np = __p.__node_;
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
+        "unordered container erase(iterator) called with an iterator not"
+        " referring to this container");
+    _LIBCPP_ASSERT(__p != end(),
+        "unordered container erase(iterator) called with a non-dereferenceable iterator");
+    iterator __r(__np, this);
+#else
+    iterator __r(__np);
+#endif
+    ++__r;
+    remove(__p);
+    return __r;
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::erase(const_iterator __first,
+                                                const_iterator __last)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__first) == this,
+        "unodered container::erase(iterator, iterator) called with an iterator not"
+        " referring to this unodered container");
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__last) == this,
+        "unodered container::erase(iterator, iterator) called with an iterator not"
+        " referring to this unodered container");
+#endif
+    for (const_iterator __p = __first; __first != __last; __p = __first)
+    {
+        ++__first;
+        erase(__p);
+    }
+    __node_pointer __np = __last.__node_;
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    return iterator (__np, this);
+#else
+    return iterator (__np);
+#endif
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class _Key>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__erase_unique(const _Key& __k)
+{
+    iterator __i = find(__k);
+    if (__i == end())
+        return 0;
+    erase(__i);
+    return 1;
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class _Key>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__erase_multi(const _Key& __k)
+{
+    size_type __r = 0;
+    iterator __i = find(__k);
+    if (__i != end())
+    {
+        iterator __e = end();
+        do
+        {
+            erase(__i++);
+            ++__r;
+        } while (__i != __e && key_eq()(*__i, __k));
+    }
+    return __r;
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::remove(const_iterator __p) _NOEXCEPT
+{
+    // current node
+    __node_pointer __cn = __p.__node_;
+    size_type __bc = bucket_count();
+    size_t __chash = __constrain_hash(__cn->__hash_, __bc);
+    // find previous node
+    __node_pointer __pn = __bucket_list_[__chash];
+    for (; __pn->__next_ != __cn; __pn = __pn->__next_)
+        ;
+    // Fix up __bucket_list_
+        // if __pn is not in same bucket (before begin is not in same bucket) &&
+        //    if __cn->__next_ is not in same bucket (nullptr is not in same bucket)
+    if (__pn == static_cast<__node_pointer>(pointer_traits<__node_base_pointer>::pointer_to(__p1_.first()))
+                            || __constrain_hash(__pn->__hash_, __bc) != __chash)
+    {
+        if (__cn->__next_ == nullptr || __constrain_hash(__cn->__next_->__hash_, __bc) != __chash)
+            __bucket_list_[__chash] = nullptr;
+    }
+        // if __cn->__next_ is not in same bucket (nullptr is in same bucket)
+    if (__cn->__next_ != nullptr)
+    {
+        size_t __nhash = __constrain_hash(__cn->__next_->__hash_, __bc);
+        if (__nhash != __chash)
+            __bucket_list_[__nhash] = __pn;
+    }
+    // remove __cn
+    __pn->__next_ = __cn->__next_;
+    __cn->__next_ = nullptr;
+    --size();
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __c_node* __c = __get_db()->__find_c_and_lock(this);
+    for (__i_node** __p = __c->end_; __p != __c->beg_; )
+    {
+        --__p;
+        iterator* __i = static_cast<iterator*>((*__p)->__i_);
+        if (__i->__node_ == __cn)
+        {
+            (*__p)->__c_ = nullptr;
+            if (--__c->end_ != __p)
+                memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
+        }
+    }
+    __get_db()->unlock();
+#endif
+    return __node_holder(__cn, _Dp(__node_alloc(), true));
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class _Key>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__count_unique(const _Key& __k) const
+{
+    return static_cast<size_type>(find(__k) != end());
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class _Key>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__count_multi(const _Key& __k) const
+{
+    size_type __r = 0;
+    const_iterator __i = find(__k);
+    if (__i != end())
+    {
+        const_iterator __e = end();
+        do
+        {
+            ++__i;
+            ++__r;
+        } while (__i != __e && key_eq()(*__i, __k));
+    }
+    return __r;
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class _Key>
+pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator,
+     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_unique(
+        const _Key& __k)
+{
+    iterator __i = find(__k);
+    iterator __j = __i;
+    if (__i != end())
+        ++__j;
+    return pair<iterator, iterator>(__i, __j);
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class _Key>
+pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator,
+     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_unique(
+        const _Key& __k) const
+{
+    const_iterator __i = find(__k);
+    const_iterator __j = __i;
+    if (__i != end())
+        ++__j;
+    return pair<const_iterator, const_iterator>(__i, __j);
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class _Key>
+pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator,
+     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_multi(
+        const _Key& __k)
+{
+    iterator __i = find(__k);
+    iterator __j = __i;
+    if (__i != end())
+    {
+        iterator __e = end();
+        do
+        {
+            ++__j;
+        } while (__j != __e && key_eq()(*__j, __k));
+    }
+    return pair<iterator, iterator>(__i, __j);
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+template <class _Key>
+pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator,
+     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator>
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_multi(
+        const _Key& __k) const
+{
+    const_iterator __i = find(__k);
+    const_iterator __j = __i;
+    if (__i != end())
+    {
+        const_iterator __e = end();
+        do
+        {
+            ++__j;
+        } while (__j != __e && key_eq()(*__j, __k));
+    }
+    return pair<const_iterator, const_iterator>(__i, __j);
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+void
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::swap(__hash_table& __u)
+#if _LIBCPP_STD_VER <= 11
+    _NOEXCEPT_(
+        __is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value
+        && (!allocator_traits<__pointer_allocator>::propagate_on_container_swap::value
+              || __is_nothrow_swappable<__pointer_allocator>::value)
+        && (!__node_traits::propagate_on_container_swap::value
+              || __is_nothrow_swappable<__node_allocator>::value)
+            )
+#else
+  _NOEXCEPT_(__is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value)
+#endif
+{
+    {
+    __node_pointer_pointer __npp = __bucket_list_.release();
+    __bucket_list_.reset(__u.__bucket_list_.release());
+    __u.__bucket_list_.reset(__npp);
+    }
+    _VSTD::swap(__bucket_list_.get_deleter().size(), __u.__bucket_list_.get_deleter().size());
+    __swap_allocator(__bucket_list_.get_deleter().__alloc(),
+             __u.__bucket_list_.get_deleter().__alloc());
+    __swap_allocator(__node_alloc(), __u.__node_alloc());
+    _VSTD::swap(__p1_.first().__next_, __u.__p1_.first().__next_);
+    __p2_.swap(__u.__p2_);
+    __p3_.swap(__u.__p3_);
+    if (size() > 0)
+        __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash_, bucket_count())] =
+            static_cast<__node_pointer>(pointer_traits<__node_base_pointer>::pointer_to(__p1_.first()));
+    if (__u.size() > 0)
+        __u.__bucket_list_[__constrain_hash(__u.__p1_.first().__next_->__hash_, __u.bucket_count())] =
+            static_cast<__node_pointer>(pointer_traits<__node_base_pointer>::pointer_to(__u.__p1_.first()));
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->swap(this, &__u);
+#endif
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::bucket_size(size_type __n) const
+{
+    _LIBCPP_ASSERT(__n < bucket_count(),
+        "unordered container::bucket_size(n) called with n >= bucket_count()");
+    __node_const_pointer __np = __bucket_list_[__n];
+    size_type __bc = bucket_count();
+    size_type __r = 0;
+    if (__np != nullptr)
+    {
+        for (__np = __np->__next_; __np != nullptr &&
+                                   __constrain_hash(__np->__hash_, __bc) == __n;
+                                                    __np = __np->__next_, ++__r)
+            ;
+    }
+    return __r;
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(__hash_table<_Tp, _Hash, _Equal, _Alloc>& __x,
+     __hash_table<_Tp, _Hash, _Equal, _Alloc>& __y)
+    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
+{
+    __x.swap(__y);
+}
+
+#if _LIBCPP_DEBUG_LEVEL >= 2
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+bool
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__dereferenceable(const const_iterator* __i) const
+{
+    return __i->__node_ != nullptr;
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+bool
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__decrementable(const const_iterator*) const
+{
+    return false;
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+bool
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__addable(const const_iterator*, ptrdiff_t) const
+{
+    return false;
+}
+
+template <class _Tp, class _Hash, class _Equal, class _Alloc>
+bool
+__hash_table<_Tp, _Hash, _Equal, _Alloc>::__subscriptable(const const_iterator*, ptrdiff_t) const
+{
+    return false;
+}
+
+#endif  // _LIBCPP_DEBUG_LEVEL >= 2
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP__HASH_TABLE

diff --git a/libcxx/include/__locale b/libcxx/include/__locale
new file mode 100644
index 0000000..1989558
--- /dev/null
+++ b/libcxx/include/__locale

@@ -0,0 +1,1475 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___LOCALE
+#define _LIBCPP___LOCALE
+
+#include <__config>
+#include <string>
+#include <memory>
+#include <utility>
+#include <mutex>
+#include <cstdint>
+#include <cctype>
+#include <locale.h>
+#if defined(_LIBCPP_MSVCRT) || defined(__MINGW32__)
+# include <support/win32/locale_win32.h>
+#elif defined(_AIX)
+# include <support/ibm/xlocale.h>
+#elif defined(__ANDROID__)
+// Android gained the locale aware functions in L (API level 21)
+# include <android/api-level.h>
+# if __ANDROID_API__ <= 20
+#  include <support/android/locale_bionic.h>
+# endif
+#elif defined(__sun__)
+# include <xlocale.h>
+# include <support/solaris/xlocale.h>
+#elif defined(_NEWLIB_VERSION)
+# include <support/newlib/xlocale.h>
+#elif (defined(__GLIBC__) || defined(__APPLE__)      || defined(__FreeBSD__) \
+    || defined(__EMSCRIPTEN__) || defined(__IBMCPP__))
+# include <xlocale.h>
+#endif // __GLIBC__ || __APPLE__ || __FreeBSD__ || __sun__ || __EMSCRIPTEN__ || __IBMCPP__
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+class _LIBCPP_TYPE_VIS locale;
+
+template <class _Facet>
+_LIBCPP_INLINE_VISIBILITY
+bool
+has_facet(const locale&) _NOEXCEPT;
+
+template <class _Facet>
+_LIBCPP_INLINE_VISIBILITY
+const _Facet&
+use_facet(const locale&);
+
+class _LIBCPP_TYPE_VIS locale
+{
+public:
+    // types:
+    class _LIBCPP_TYPE_VIS facet;
+    class _LIBCPP_TYPE_VIS id;
+
+    typedef int category;
+    static const category // values assigned here are for exposition only
+        none     = 0,
+        collate  = LC_COLLATE_MASK,
+        ctype    = LC_CTYPE_MASK,
+        monetary = LC_MONETARY_MASK,
+        numeric  = LC_NUMERIC_MASK,
+        time     = LC_TIME_MASK,
+        messages = LC_MESSAGES_MASK,
+        all = collate | ctype | monetary | numeric | time | messages;
+
+    // construct/copy/destroy:
+    locale()  _NOEXCEPT;
+    locale(const locale&)  _NOEXCEPT;
+    explicit locale(const char*);
+    explicit locale(const string&);
+    locale(const locale&, const char*, category);
+    locale(const locale&, const string&, category);
+    template <class _Facet>
+        _LIBCPP_INLINE_VISIBILITY locale(const locale&, _Facet*);
+    locale(const locale&, const locale&, category);
+
+    ~locale();
+
+    const locale& operator=(const locale&)  _NOEXCEPT;
+
+    template <class _Facet> locale combine(const locale&) const;
+
+    // locale operations:
+    string name() const;
+    bool operator==(const locale&) const;
+    bool operator!=(const locale& __y) const {return !(*this == __y);}
+    template <class _CharT, class _Traits, class _Allocator>
+      bool operator()(const basic_string<_CharT, _Traits, _Allocator>&,
+                      const basic_string<_CharT, _Traits, _Allocator>&) const;
+
+    // global locale objects:
+    static locale global(const locale&);
+    static const locale& classic();
+
+private:
+    class __imp;
+    __imp* __locale_;
+
+    void __install_ctor(const locale&, facet*, long);
+    static locale& __global();
+    bool has_facet(id&) const;
+    const facet* use_facet(id&) const;
+
+    template <class _Facet> friend bool has_facet(const locale&)  _NOEXCEPT;
+    template <class _Facet> friend const _Facet& use_facet(const locale&);
+};
+
+class _LIBCPP_TYPE_VIS locale::facet
+    : public __shared_count
+{
+protected:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit facet(size_t __refs = 0)
+        : __shared_count(static_cast<long>(__refs)-1) {}
+
+    virtual ~facet();
+
+//    facet(const facet&) = delete;     // effectively done in __shared_count
+//    void operator=(const facet&) = delete;
+private:
+    virtual void __on_zero_shared() _NOEXCEPT;
+};
+
+class _LIBCPP_TYPE_VIS locale::id
+{
+    once_flag      __flag_;
+    int32_t        __id_;
+
+    static int32_t __next_id;
+public:
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR id() :__id_(0) {}
+private:
+    void __init();
+    void operator=(const id&); // = delete;
+    id(const id&); // = delete;
+public:  // only needed for tests
+    long __get();
+
+    friend class locale;
+    friend class locale::__imp;
+};
+
+template <class _Facet>
+inline _LIBCPP_INLINE_VISIBILITY
+locale::locale(const locale& __other, _Facet* __f)
+{
+    __install_ctor(__other, __f, __f ? __f->id.__get() : 0);
+}
+
+template <class _Facet>
+locale
+locale::combine(const locale& __other) const
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (!_VSTD::has_facet<_Facet>(__other))
+        throw runtime_error("locale::combine: locale missing facet");
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return locale(*this, &const_cast<_Facet&>(_VSTD::use_facet<_Facet>(__other)));
+}
+
+template <class _Facet>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+has_facet(const locale& __l)  _NOEXCEPT
+{
+    return __l.has_facet(_Facet::id);
+}
+
+template <class _Facet>
+inline _LIBCPP_INLINE_VISIBILITY
+const _Facet&
+use_facet(const locale& __l)
+{
+    return static_cast<const _Facet&>(*__l.use_facet(_Facet::id));
+}
+
+// template <class _CharT> class collate;
+
+template <class _CharT>
+class _LIBCPP_TYPE_VIS_ONLY collate
+    : public locale::facet
+{
+public:
+    typedef _CharT char_type;
+    typedef basic_string<char_type> string_type;
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit collate(size_t __refs = 0)
+        : locale::facet(__refs) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    int compare(const char_type* __lo1, const char_type* __hi1,
+                const char_type* __lo2, const char_type* __hi2) const
+    {
+        return do_compare(__lo1, __hi1, __lo2, __hi2);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    string_type transform(const char_type* __lo, const char_type* __hi) const
+    {
+        return do_transform(__lo, __hi);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    long hash(const char_type* __lo, const char_type* __hi) const
+    {
+        return do_hash(__lo, __hi);
+    }
+
+    static locale::id id;
+
+protected:
+    ~collate();
+    virtual int do_compare(const char_type* __lo1, const char_type* __hi1,
+                           const char_type* __lo2, const char_type* __hi2) const;
+    virtual string_type do_transform(const char_type* __lo, const char_type* __hi) const
+        {return string_type(__lo, __hi);}
+    virtual long do_hash(const char_type* __lo, const char_type* __hi) const;
+};
+
+template <class _CharT> locale::id collate<_CharT>::id;
+
+template <class _CharT>
+collate<_CharT>::~collate()
+{
+}
+
+template <class _CharT>
+int
+collate<_CharT>::do_compare(const char_type* __lo1, const char_type* __hi1,
+                            const char_type* __lo2, const char_type* __hi2) const
+{
+    for (; __lo2 != __hi2; ++__lo1, ++__lo2)
+    {
+        if (__lo1 == __hi1 || *__lo1 < *__lo2)
+            return -1;
+        if (*__lo2 < *__lo1)
+            return 1;
+    }
+    return __lo1 != __hi1;
+}
+
+template <class _CharT>
+long
+collate<_CharT>::do_hash(const char_type* __lo, const char_type* __hi) const
+{
+    size_t __h = 0;
+    const size_t __sr = __CHAR_BIT__ * sizeof(size_t) - 8;
+    const size_t __mask = size_t(0xF) << (__sr + 4);
+    for(const char_type* __p = __lo; __p != __hi; ++__p)
+    {
+        __h = (__h << 4) + static_cast<size_t>(*__p);
+        size_t __g = __h & __mask;
+        __h ^= __g | (__g >> __sr);
+    }
+    return static_cast<long>(__h);
+}
+
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS collate<char>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS collate<wchar_t>)
+
+// template <class CharT> class collate_byname;
+
+template <class _CharT> class _LIBCPP_TYPE_VIS_ONLY collate_byname;
+
+template <>
+class _LIBCPP_TYPE_VIS collate_byname<char>
+    : public collate<char>
+{
+    locale_t __l;
+public:
+    typedef char char_type;
+    typedef basic_string<char_type> string_type;
+
+    explicit collate_byname(const char* __n, size_t __refs = 0);
+    explicit collate_byname(const string& __n, size_t __refs = 0);
+
+protected:
+    ~collate_byname();
+    virtual int do_compare(const char_type* __lo1, const char_type* __hi1,
+                           const char_type* __lo2, const char_type* __hi2) const;
+    virtual string_type do_transform(const char_type* __lo, const char_type* __hi) const;
+};
+
+template <>
+class _LIBCPP_TYPE_VIS collate_byname<wchar_t>
+    : public collate<wchar_t>
+{
+    locale_t __l;
+public:
+    typedef wchar_t char_type;
+    typedef basic_string<char_type> string_type;
+
+    explicit collate_byname(const char* __n, size_t __refs = 0);
+    explicit collate_byname(const string& __n, size_t __refs = 0);
+
+protected:
+    ~collate_byname();
+
+    virtual int do_compare(const char_type* __lo1, const char_type* __hi1,
+                           const char_type* __lo2, const char_type* __hi2) const;
+    virtual string_type do_transform(const char_type* __lo, const char_type* __hi) const;
+};
+
+template <class _CharT, class _Traits, class _Allocator>
+bool
+locale::operator()(const basic_string<_CharT, _Traits, _Allocator>& __x,
+                   const basic_string<_CharT, _Traits, _Allocator>& __y) const
+{
+    return _VSTD::use_facet<_VSTD::collate<_CharT> >(*this).compare(
+                                       __x.data(), __x.data() + __x.size(),
+                                       __y.data(), __y.data() + __y.size()) < 0;
+}
+
+// template <class charT> class ctype
+
+class _LIBCPP_TYPE_VIS ctype_base
+{
+public:
+#ifdef __GLIBC__
+    typedef unsigned short mask;
+    static const mask space  = _ISspace;
+    static const mask print  = _ISprint;
+    static const mask cntrl  = _IScntrl;
+    static const mask upper  = _ISupper;
+    static const mask lower  = _ISlower;
+    static const mask alpha  = _ISalpha;
+    static const mask digit  = _ISdigit;
+    static const mask punct  = _ISpunct;
+    static const mask xdigit = _ISxdigit;
+    static const mask blank  = _ISblank;
+#elif defined(_WIN32)
+    typedef unsigned short mask;
+    static const mask space  = _SPACE;
+    static const mask print  = _BLANK|_PUNCT|_ALPHA|_DIGIT;
+    static const mask cntrl  = _CONTROL;
+    static const mask upper  = _UPPER;
+    static const mask lower  = _LOWER;
+    static const mask alpha  = _ALPHA;
+    static const mask digit  = _DIGIT;
+    static const mask punct  = _PUNCT;
+    static const mask xdigit = _HEX;
+    static const mask blank  = _BLANK;
+# define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_PRINT
+#elif defined(__APPLE__) || defined(__FreeBSD__) || defined(__EMSCRIPTEN__) || defined(__NetBSD__)
+# ifdef __APPLE__
+    typedef __uint32_t mask;
+# elif defined(__FreeBSD__)
+    typedef unsigned long mask;
+# elif defined(__EMSCRIPTEN__) ||  defined(__NetBSD__)
+    typedef unsigned short mask;
+# endif
+    static const mask space  = _CTYPE_S;
+    static const mask print  = _CTYPE_R;
+    static const mask cntrl  = _CTYPE_C;
+    static const mask upper  = _CTYPE_U;
+    static const mask lower  = _CTYPE_L;
+    static const mask alpha  = _CTYPE_A;
+    static const mask digit  = _CTYPE_D;
+    static const mask punct  = _CTYPE_P;
+    static const mask xdigit = _CTYPE_X;
+
+# if defined(__NetBSD__)
+    static const mask blank  = _CTYPE_BL;
+# else
+    static const mask blank  = _CTYPE_B;
+# endif
+#elif defined(__sun__) || defined(_AIX)
+    typedef unsigned int mask;
+    static const mask space  = _ISSPACE;
+    static const mask print  = _ISPRINT;
+    static const mask cntrl  = _ISCNTRL;
+    static const mask upper  = _ISUPPER;
+    static const mask lower  = _ISLOWER;
+    static const mask alpha  = _ISALPHA;
+    static const mask digit  = _ISDIGIT;
+    static const mask punct  = _ISPUNCT;
+    static const mask xdigit = _ISXDIGIT;
+    static const mask blank  = _ISBLANK;
+#elif defined(_NEWLIB_VERSION)
+    // Same type as Newlib's _ctype_ array in newlib/libc/include/ctype.h.
+    typedef char mask;
+    static const mask space  = _S;
+    static const mask print  = _P | _U | _L | _N | _B;
+    static const mask cntrl  = _C;
+    static const mask upper  = _U;
+    static const mask lower  = _L;
+    static const mask alpha  = _U | _L;
+    static const mask digit  = _N;
+    static const mask punct  = _P;
+    static const mask xdigit = _X | _N;
+    static const mask blank  = _B;
+# define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_PRINT
+# define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_ALPHA
+# define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_XDIGIT
+#else
+    typedef unsigned long mask;
+    static const mask space  = 1<<0;
+    static const mask print  = 1<<1;
+    static const mask cntrl  = 1<<2;
+    static const mask upper  = 1<<3;
+    static const mask lower  = 1<<4;
+    static const mask alpha  = 1<<5;
+    static const mask digit  = 1<<6;
+    static const mask punct  = 1<<7;
+    static const mask xdigit = 1<<8;
+    static const mask blank  = 1<<9;
+#endif
+    static const mask alnum  = alpha | digit;
+    static const mask graph  = alnum | punct;
+
+    _LIBCPP_ALWAYS_INLINE ctype_base() {}
+};
+
+template <class _CharT> class _LIBCPP_TYPE_VIS_ONLY ctype;
+
+template <>
+class _LIBCPP_TYPE_VIS ctype<wchar_t>
+    : public locale::facet,
+      public ctype_base
+{
+public:
+    typedef wchar_t char_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit ctype(size_t __refs = 0)
+        : locale::facet(__refs) {}
+
+    _LIBCPP_ALWAYS_INLINE
+    bool is(mask __m, char_type __c) const
+    {
+        return do_is(__m, __c);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    const char_type* is(const char_type* __low, const char_type* __high, mask* __vec) const
+    {
+        return do_is(__low, __high, __vec);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    const char_type* scan_is(mask __m, const char_type* __low, const char_type* __high) const
+    {
+        return do_scan_is(__m, __low, __high);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    const char_type* scan_not(mask __m, const char_type* __low, const char_type* __high) const
+    {
+        return do_scan_not(__m, __low, __high);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    char_type toupper(char_type __c) const
+    {
+        return do_toupper(__c);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    const char_type* toupper(char_type* __low, const char_type* __high) const
+    {
+        return do_toupper(__low, __high);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    char_type tolower(char_type __c) const
+    {
+        return do_tolower(__c);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    const char_type* tolower(char_type* __low, const char_type* __high) const
+    {
+        return do_tolower(__low, __high);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    char_type widen(char __c) const
+    {
+        return do_widen(__c);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    const char* widen(const char* __low, const char* __high, char_type* __to) const
+    {
+        return do_widen(__low, __high, __to);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    char narrow(char_type __c, char __dfault) const
+    {
+        return do_narrow(__c, __dfault);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    const char_type* narrow(const char_type* __low, const char_type* __high, char __dfault, char* __to) const
+    {
+        return do_narrow(__low, __high, __dfault, __to);
+    }
+
+    static locale::id id;
+
+protected:
+    ~ctype();
+    virtual bool do_is(mask __m, char_type __c) const;
+    virtual const char_type* do_is(const char_type* __low, const char_type* __high, mask* __vec) const;
+    virtual const char_type* do_scan_is(mask __m, const char_type* __low, const char_type* __high) const;
+    virtual const char_type* do_scan_not(mask __m, const char_type* __low, const char_type* __high) const;
+    virtual char_type do_toupper(char_type) const;
+    virtual const char_type* do_toupper(char_type* __low, const char_type* __high) const;
+    virtual char_type do_tolower(char_type) const;
+    virtual const char_type* do_tolower(char_type* __low, const char_type* __high) const;
+    virtual char_type do_widen(char) const;
+    virtual const char* do_widen(const char* __low, const char* __high, char_type* __dest) const;
+    virtual char do_narrow(char_type, char __dfault) const;
+    virtual const char_type* do_narrow(const char_type* __low, const char_type* __high, char __dfault, char* __dest) const;
+};
+
+template <>
+class _LIBCPP_TYPE_VIS ctype<char>
+    : public locale::facet, public ctype_base
+{
+    const mask* __tab_;
+    bool        __del_;
+public:
+    typedef char char_type;
+
+    explicit ctype(const mask* __tab = 0, bool __del = false, size_t __refs = 0);
+
+    _LIBCPP_ALWAYS_INLINE
+    bool is(mask __m, char_type __c) const
+    {
+        return isascii(__c) ? (__tab_[static_cast<int>(__c)] & __m) !=0 : false;
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    const char_type* is(const char_type* __low, const char_type* __high, mask* __vec) const
+    {
+        for (; __low != __high; ++__low, ++__vec)
+            *__vec = isascii(*__low) ? __tab_[static_cast<int>(*__low)] : 0;
+        return __low;
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    const char_type* scan_is (mask __m, const char_type* __low, const char_type* __high) const
+    {
+        for (; __low != __high; ++__low)
+            if (isascii(*__low) && (__tab_[static_cast<int>(*__low)] & __m))
+                break;
+        return __low;
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    const char_type* scan_not(mask __m, const char_type* __low, const char_type* __high) const
+    {
+        for (; __low != __high; ++__low)
+            if (!(isascii(*__low) && (__tab_[static_cast<int>(*__low)] & __m)))
+                break;
+        return __low;
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    char_type toupper(char_type __c) const
+    {
+        return do_toupper(__c);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    const char_type* toupper(char_type* __low, const char_type* __high) const
+    {
+        return do_toupper(__low, __high);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    char_type tolower(char_type __c) const
+    {
+        return do_tolower(__c);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    const char_type* tolower(char_type* __low, const char_type* __high) const
+    {
+        return do_tolower(__low, __high);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    char_type widen(char __c) const
+    {
+        return do_widen(__c);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    const char* widen(const char* __low, const char* __high, char_type* __to) const
+    {
+        return do_widen(__low, __high, __to);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    char narrow(char_type __c, char __dfault) const
+    {
+        return do_narrow(__c, __dfault);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    const char* narrow(const char_type* __low, const char_type* __high, char __dfault, char* __to) const
+    {
+        return do_narrow(__low, __high, __dfault, __to);
+    }
+
+    static locale::id id;
+
+#ifdef _CACHED_RUNES
+    static const size_t table_size = _CACHED_RUNES;
+#else
+    static const size_t table_size = 256;  // FIXME: Don't hardcode this.
+#endif
+    _LIBCPP_ALWAYS_INLINE const mask* table() const  _NOEXCEPT {return __tab_;}
+    static const mask* classic_table()  _NOEXCEPT;
+#if defined(__GLIBC__) || defined(__EMSCRIPTEN__)
+    static const int* __classic_upper_table() _NOEXCEPT;
+    static const int* __classic_lower_table() _NOEXCEPT;
+#endif
+#if defined(__NetBSD__)
+    static const short* __classic_upper_table() _NOEXCEPT;
+    static const short* __classic_lower_table() _NOEXCEPT;
+#endif
+
+protected:
+    ~ctype();
+    virtual char_type do_toupper(char_type __c) const;
+    virtual const char_type* do_toupper(char_type* __low, const char_type* __high) const;
+    virtual char_type do_tolower(char_type __c) const;
+    virtual const char_type* do_tolower(char_type* __low, const char_type* __high) const;
+    virtual char_type do_widen(char __c) const;
+    virtual const char* do_widen(const char* __low, const char* __high, char_type* __to) const;
+    virtual char do_narrow(char_type __c, char __dfault) const;
+    virtual const char* do_narrow(const char_type* __low, const char_type* __high, char __dfault, char* __to) const;
+};
+
+// template <class CharT> class ctype_byname;
+
+template <class _CharT> class _LIBCPP_TYPE_VIS_ONLY ctype_byname;
+
+template <>
+class _LIBCPP_TYPE_VIS ctype_byname<char>
+    : public ctype<char>
+{
+    locale_t __l;
+
+public:
+    explicit ctype_byname(const char*, size_t = 0);
+    explicit ctype_byname(const string&, size_t = 0);
+
+protected:
+    ~ctype_byname();
+    virtual char_type do_toupper(char_type) const;
+    virtual const char_type* do_toupper(char_type* __low, const char_type* __high) const;
+    virtual char_type do_tolower(char_type) const;
+    virtual const char_type* do_tolower(char_type* __low, const char_type* __high) const;
+};
+
+template <>
+class _LIBCPP_TYPE_VIS ctype_byname<wchar_t>
+    : public ctype<wchar_t>
+{
+    locale_t __l;
+
+public:
+    explicit ctype_byname(const char*, size_t = 0);
+    explicit ctype_byname(const string&, size_t = 0);
+
+protected:
+    ~ctype_byname();
+    virtual bool do_is(mask __m, char_type __c) const;
+    virtual const char_type* do_is(const char_type* __low, const char_type* __high, mask* __vec) const;
+    virtual const char_type* do_scan_is(mask __m, const char_type* __low, const char_type* __high) const;
+    virtual const char_type* do_scan_not(mask __m, const char_type* __low, const char_type* __high) const;
+    virtual char_type do_toupper(char_type) const;
+    virtual const char_type* do_toupper(char_type* __low, const char_type* __high) const;
+    virtual char_type do_tolower(char_type) const;
+    virtual const char_type* do_tolower(char_type* __low, const char_type* __high) const;
+    virtual char_type do_widen(char) const;
+    virtual const char* do_widen(const char* __low, const char* __high, char_type* __dest) const;
+    virtual char do_narrow(char_type, char __dfault) const;
+    virtual const char_type* do_narrow(const char_type* __low, const char_type* __high, char __dfault, char* __dest) const;
+};
+
+template <class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+isspace(_CharT __c, const locale& __loc)
+{
+    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::space, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+isprint(_CharT __c, const locale& __loc)
+{
+    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::print, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+iscntrl(_CharT __c, const locale& __loc)
+{
+    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::cntrl, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+isupper(_CharT __c, const locale& __loc)
+{
+    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::upper, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+islower(_CharT __c, const locale& __loc)
+{
+    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::lower, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+isalpha(_CharT __c, const locale& __loc)
+{
+    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::alpha, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+isdigit(_CharT __c, const locale& __loc)
+{
+    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::digit, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+ispunct(_CharT __c, const locale& __loc)
+{
+    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::punct, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+isxdigit(_CharT __c, const locale& __loc)
+{
+    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::xdigit, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+isalnum(_CharT __c, const locale& __loc)
+{
+    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::alnum, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+isgraph(_CharT __c, const locale& __loc)
+{
+    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::graph, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+_CharT
+toupper(_CharT __c, const locale& __loc)
+{
+    return use_facet<ctype<_CharT> >(__loc).toupper(__c);
+}
+
+template <class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+_CharT
+tolower(_CharT __c, const locale& __loc)
+{
+    return use_facet<ctype<_CharT> >(__loc).tolower(__c);
+}
+
+// codecvt_base
+
+class _LIBCPP_TYPE_VIS codecvt_base
+{
+public:
+    _LIBCPP_ALWAYS_INLINE codecvt_base() {}
+    enum result {ok, partial, error, noconv};
+};
+
+// template <class internT, class externT, class stateT> class codecvt;
+
+template <class _InternT, class _ExternT, class _StateT> class _LIBCPP_TYPE_VIS_ONLY codecvt;
+
+// template <> class codecvt<char, char, mbstate_t>
+
+template <>
+class _LIBCPP_TYPE_VIS codecvt<char, char, mbstate_t>
+    : public locale::facet,
+      public codecvt_base
+{
+public:
+    typedef char      intern_type;
+    typedef char      extern_type;
+    typedef mbstate_t state_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit codecvt(size_t __refs = 0)
+        : locale::facet(__refs) {}
+
+    _LIBCPP_ALWAYS_INLINE
+    result out(state_type& __st,
+               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const
+    {
+        return do_out(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    result unshift(state_type& __st,
+                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const
+    {
+        return do_unshift(__st, __to, __to_end, __to_nxt);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    result in(state_type& __st,
+              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const
+    {
+        return do_in(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    int encoding() const  _NOEXCEPT
+    {
+        return do_encoding();
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    bool always_noconv() const  _NOEXCEPT
+    {
+        return do_always_noconv();
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    int length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const
+    {
+        return do_length(__st, __frm, __end, __mx);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    int max_length() const  _NOEXCEPT
+    {
+        return do_max_length();
+    }
+
+    static locale::id id;
+
+protected:
+    _LIBCPP_ALWAYS_INLINE
+    explicit codecvt(const char*, size_t __refs = 0)
+        : locale::facet(__refs) {}
+
+    ~codecvt();
+
+    virtual result do_out(state_type& __st,
+                          const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+                          extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual result do_in(state_type& __st,
+                         const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+                         intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
+    virtual result do_unshift(state_type& __st,
+                              extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual int do_encoding() const  _NOEXCEPT;
+    virtual bool do_always_noconv() const  _NOEXCEPT;
+    virtual int do_length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const;
+    virtual int do_max_length() const  _NOEXCEPT;
+};
+
+// template <> class codecvt<wchar_t, char, mbstate_t>
+
+template <>
+class _LIBCPP_TYPE_VIS codecvt<wchar_t, char, mbstate_t>
+    : public locale::facet,
+      public codecvt_base
+{
+    locale_t __l;
+public:
+    typedef wchar_t   intern_type;
+    typedef char      extern_type;
+    typedef mbstate_t state_type;
+
+    explicit codecvt(size_t __refs = 0);
+
+    _LIBCPP_ALWAYS_INLINE
+    result out(state_type& __st,
+               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const
+    {
+        return do_out(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    result unshift(state_type& __st,
+                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const
+    {
+        return do_unshift(__st, __to, __to_end, __to_nxt);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    result in(state_type& __st,
+              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const
+    {
+        return do_in(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    int encoding() const  _NOEXCEPT
+    {
+        return do_encoding();
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    bool always_noconv() const  _NOEXCEPT
+    {
+        return do_always_noconv();
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    int length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const
+    {
+        return do_length(__st, __frm, __end, __mx);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    int max_length() const  _NOEXCEPT
+    {
+        return do_max_length();
+    }
+
+    static locale::id id;
+
+protected:
+    explicit codecvt(const char*, size_t __refs = 0);
+
+    ~codecvt();
+
+    virtual result do_out(state_type& __st,
+                          const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+                          extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual result do_in(state_type& __st,
+                         const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+                         intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
+    virtual result do_unshift(state_type& __st,
+                              extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual int do_encoding() const  _NOEXCEPT;
+    virtual bool do_always_noconv() const  _NOEXCEPT;
+    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end, size_t __mx) const;
+    virtual int do_max_length() const  _NOEXCEPT;
+};
+
+// template <> class codecvt<char16_t, char, mbstate_t>
+
+template <>
+class _LIBCPP_TYPE_VIS codecvt<char16_t, char, mbstate_t>
+    : public locale::facet,
+      public codecvt_base
+{
+public:
+    typedef char16_t  intern_type;
+    typedef char      extern_type;
+    typedef mbstate_t state_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit codecvt(size_t __refs = 0)
+        : locale::facet(__refs) {}
+
+    _LIBCPP_ALWAYS_INLINE
+    result out(state_type& __st,
+               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const
+    {
+        return do_out(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    result unshift(state_type& __st,
+                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const
+    {
+        return do_unshift(__st, __to, __to_end, __to_nxt);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    result in(state_type& __st,
+              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const
+    {
+        return do_in(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    int encoding() const  _NOEXCEPT
+    {
+        return do_encoding();
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    bool always_noconv() const  _NOEXCEPT
+    {
+        return do_always_noconv();
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    int length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const
+    {
+        return do_length(__st, __frm, __end, __mx);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    int max_length() const  _NOEXCEPT
+    {
+        return do_max_length();
+    }
+
+    static locale::id id;
+
+protected:
+    _LIBCPP_ALWAYS_INLINE
+    explicit codecvt(const char*, size_t __refs = 0)
+        : locale::facet(__refs) {}
+
+    ~codecvt();
+
+    virtual result do_out(state_type& __st,
+                          const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+                          extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual result do_in(state_type& __st,
+                         const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+                         intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
+    virtual result do_unshift(state_type& __st,
+                              extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual int do_encoding() const  _NOEXCEPT;
+    virtual bool do_always_noconv() const  _NOEXCEPT;
+    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end, size_t __mx) const;
+    virtual int do_max_length() const  _NOEXCEPT;
+};
+
+// template <> class codecvt<char32_t, char, mbstate_t>
+
+template <>
+class _LIBCPP_TYPE_VIS codecvt<char32_t, char, mbstate_t>
+    : public locale::facet,
+      public codecvt_base
+{
+public:
+    typedef char32_t  intern_type;
+    typedef char      extern_type;
+    typedef mbstate_t state_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit codecvt(size_t __refs = 0)
+        : locale::facet(__refs) {}
+
+    _LIBCPP_ALWAYS_INLINE
+    result out(state_type& __st,
+               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const
+    {
+        return do_out(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    result unshift(state_type& __st,
+                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const
+    {
+        return do_unshift(__st, __to, __to_end, __to_nxt);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    result in(state_type& __st,
+              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const
+    {
+        return do_in(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    int encoding() const  _NOEXCEPT
+    {
+        return do_encoding();
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    bool always_noconv() const  _NOEXCEPT
+    {
+        return do_always_noconv();
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    int length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const
+    {
+        return do_length(__st, __frm, __end, __mx);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    int max_length() const  _NOEXCEPT
+    {
+        return do_max_length();
+    }
+
+    static locale::id id;
+
+protected:
+    _LIBCPP_ALWAYS_INLINE
+    explicit codecvt(const char*, size_t __refs = 0)
+        : locale::facet(__refs) {}
+
+    ~codecvt();
+
+    virtual result do_out(state_type& __st,
+                          const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+                          extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual result do_in(state_type& __st,
+                         const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+                         intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
+    virtual result do_unshift(state_type& __st,
+                              extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual int do_encoding() const  _NOEXCEPT;
+    virtual bool do_always_noconv() const  _NOEXCEPT;
+    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end, size_t __mx) const;
+    virtual int do_max_length() const  _NOEXCEPT;
+};
+
+// template <class _InternT, class _ExternT, class _StateT> class codecvt_byname
+
+template <class _InternT, class _ExternT, class _StateT>
+class _LIBCPP_TYPE_VIS_ONLY codecvt_byname
+    : public codecvt<_InternT, _ExternT, _StateT>
+{
+public:
+    _LIBCPP_ALWAYS_INLINE
+    explicit codecvt_byname(const char* __nm, size_t __refs = 0)
+        : codecvt<_InternT, _ExternT, _StateT>(__nm, __refs) {}
+    _LIBCPP_ALWAYS_INLINE
+    explicit codecvt_byname(const string& __nm, size_t __refs = 0)
+        : codecvt<_InternT, _ExternT, _StateT>(__nm.c_str(), __refs) {}
+protected:
+    ~codecvt_byname();
+};
+
+template <class _InternT, class _ExternT, class _StateT>
+codecvt_byname<_InternT, _ExternT, _StateT>::~codecvt_byname()
+{
+}
+
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS codecvt_byname<char, char, mbstate_t>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS codecvt_byname<wchar_t, char, mbstate_t>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS codecvt_byname<char16_t, char, mbstate_t>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS codecvt_byname<char32_t, char, mbstate_t>)
+
+_LIBCPP_FUNC_VIS void __throw_runtime_error(const char*);
+
+template <size_t _Np>
+struct __narrow_to_utf8
+{
+    template <class _OutputIterator, class _CharT>
+    _OutputIterator
+    operator()(_OutputIterator __s, const _CharT* __wb, const _CharT* __we) const;
+};
+
+template <>
+struct __narrow_to_utf8<8>
+{
+    template <class _OutputIterator, class _CharT>
+    _LIBCPP_ALWAYS_INLINE
+    _OutputIterator
+    operator()(_OutputIterator __s, const _CharT* __wb, const _CharT* __we) const
+    {
+        for (; __wb < __we; ++__wb, ++__s)
+            *__s = *__wb;
+        return __s;
+    }
+};
+
+template <>
+struct __narrow_to_utf8<16>
+    : public codecvt<char16_t, char, mbstate_t>
+{
+    _LIBCPP_ALWAYS_INLINE
+    __narrow_to_utf8() : codecvt<char16_t, char, mbstate_t>(1) {}
+
+    ~__narrow_to_utf8();
+
+    template <class _OutputIterator, class _CharT>
+    _LIBCPP_ALWAYS_INLINE
+    _OutputIterator
+    operator()(_OutputIterator __s, const _CharT* __wb, const _CharT* __we) const
+    {
+        result __r = ok;
+        mbstate_t __mb;
+        while (__wb < __we && __r != error)
+        {
+            const int __sz = 32;
+            char __buf[__sz];
+            char* __bn;
+            const char16_t* __wn = (const char16_t*)__wb;
+            __r = do_out(__mb, (const char16_t*)__wb, (const char16_t*)__we, __wn,
+                         __buf, __buf+__sz, __bn);
+            if (__r == codecvt_base::error || __wn == (const char16_t*)__wb)
+                __throw_runtime_error("locale not supported");
+            for (const char* __p = __buf; __p < __bn; ++__p, ++__s)
+                *__s = *__p;
+            __wb = (const _CharT*)__wn;
+        }
+        return __s;
+    }
+};
+
+template <>
+struct __narrow_to_utf8<32>
+    : public codecvt<char32_t, char, mbstate_t>
+{
+    _LIBCPP_ALWAYS_INLINE
+    __narrow_to_utf8() : codecvt<char32_t, char, mbstate_t>(1) {}
+
+    ~__narrow_to_utf8();
+
+    template <class _OutputIterator, class _CharT>
+    _LIBCPP_ALWAYS_INLINE
+    _OutputIterator
+    operator()(_OutputIterator __s, const _CharT* __wb, const _CharT* __we) const
+    {
+        result __r = ok;
+        mbstate_t __mb;
+        while (__wb < __we && __r != error)
+        {
+            const int __sz = 32;
+            char __buf[__sz];
+            char* __bn;
+            const char32_t* __wn = (const char32_t*)__wb;
+            __r = do_out(__mb, (const char32_t*)__wb, (const char32_t*)__we, __wn,
+                         __buf, __buf+__sz, __bn);
+            if (__r == codecvt_base::error || __wn == (const char32_t*)__wb)
+                __throw_runtime_error("locale not supported");
+            for (const char* __p = __buf; __p < __bn; ++__p, ++__s)
+                *__s = *__p;
+            __wb = (const _CharT*)__wn;
+        }
+        return __s;
+    }
+};
+
+template <size_t _Np>
+struct __widen_from_utf8
+{
+    template <class _OutputIterator>
+    _OutputIterator
+    operator()(_OutputIterator __s, const char* __nb, const char* __ne) const;
+};
+
+template <>
+struct __widen_from_utf8<8>
+{
+    template <class _OutputIterator>
+    _LIBCPP_ALWAYS_INLINE
+    _OutputIterator
+    operator()(_OutputIterator __s, const char* __nb, const char* __ne) const
+    {
+        for (; __nb < __ne; ++__nb, ++__s)
+            *__s = *__nb;
+        return __s;
+    }
+};
+
+template <>
+struct __widen_from_utf8<16>
+    : public codecvt<char16_t, char, mbstate_t>
+{
+    _LIBCPP_ALWAYS_INLINE
+    __widen_from_utf8() : codecvt<char16_t, char, mbstate_t>(1) {}
+
+    ~__widen_from_utf8();
+
+    template <class _OutputIterator>
+    _LIBCPP_ALWAYS_INLINE
+    _OutputIterator
+    operator()(_OutputIterator __s, const char* __nb, const char* __ne) const
+    {
+        result __r = ok;
+        mbstate_t __mb;
+        while (__nb < __ne && __r != error)
+        {
+            const int __sz = 32;
+            char16_t __buf[__sz];
+            char16_t* __bn;
+            const char* __nn = __nb;
+            __r = do_in(__mb, __nb, __ne - __nb > __sz ? __nb+__sz : __ne, __nn,
+                        __buf, __buf+__sz, __bn);
+            if (__r == codecvt_base::error || __nn == __nb)
+                __throw_runtime_error("locale not supported");
+            for (const char16_t* __p = __buf; __p < __bn; ++__p, ++__s)
+                *__s = (wchar_t)*__p;
+            __nb = __nn;
+        }
+        return __s;
+    }
+};
+
+template <>
+struct __widen_from_utf8<32>
+    : public codecvt<char32_t, char, mbstate_t>
+{
+    _LIBCPP_ALWAYS_INLINE
+    __widen_from_utf8() : codecvt<char32_t, char, mbstate_t>(1) {}
+
+    ~__widen_from_utf8();
+
+    template <class _OutputIterator>
+    _LIBCPP_ALWAYS_INLINE
+    _OutputIterator
+    operator()(_OutputIterator __s, const char* __nb, const char* __ne) const
+    {
+        result __r = ok;
+        mbstate_t __mb;
+        while (__nb < __ne && __r != error)
+        {
+            const int __sz = 32;
+            char32_t __buf[__sz];
+            char32_t* __bn;
+            const char* __nn = __nb;
+            __r = do_in(__mb, __nb, __ne - __nb > __sz ? __nb+__sz : __ne, __nn,
+                        __buf, __buf+__sz, __bn);
+            if (__r == codecvt_base::error || __nn == __nb)
+                __throw_runtime_error("locale not supported");
+            for (const char32_t* __p = __buf; __p < __bn; ++__p, ++__s)
+                *__s = (wchar_t)*__p;
+            __nb = __nn;
+        }
+        return __s;
+    }
+};
+
+// template <class charT> class numpunct
+
+template <class _CharT> class _LIBCPP_TYPE_VIS_ONLY numpunct;
+
+template <>
+class _LIBCPP_TYPE_VIS numpunct<char>
+    : public locale::facet
+{
+public:
+    typedef char char_type;
+    typedef basic_string<char_type> string_type;
+
+    explicit numpunct(size_t __refs = 0);
+
+    _LIBCPP_ALWAYS_INLINE char_type decimal_point() const {return do_decimal_point();}
+    _LIBCPP_ALWAYS_INLINE char_type thousands_sep() const {return do_thousands_sep();}
+    _LIBCPP_ALWAYS_INLINE string grouping() const         {return do_grouping();}
+    _LIBCPP_ALWAYS_INLINE string_type truename() const    {return do_truename();}
+    _LIBCPP_ALWAYS_INLINE string_type falsename() const   {return do_falsename();}
+
+    static locale::id id;
+
+protected:
+    ~numpunct();
+    virtual char_type do_decimal_point() const;
+    virtual char_type do_thousands_sep() const;
+    virtual string do_grouping() const;
+    virtual string_type do_truename() const;
+    virtual string_type do_falsename() const;
+
+    char_type __decimal_point_;
+    char_type __thousands_sep_;
+    string __grouping_;
+};
+
+template <>
+class _LIBCPP_TYPE_VIS numpunct<wchar_t>
+    : public locale::facet
+{
+public:
+    typedef wchar_t char_type;
+    typedef basic_string<char_type> string_type;
+
+    explicit numpunct(size_t __refs = 0);
+
+    _LIBCPP_ALWAYS_INLINE char_type decimal_point() const {return do_decimal_point();}
+    _LIBCPP_ALWAYS_INLINE char_type thousands_sep() const {return do_thousands_sep();}
+    _LIBCPP_ALWAYS_INLINE string grouping() const         {return do_grouping();}
+    _LIBCPP_ALWAYS_INLINE string_type truename() const    {return do_truename();}
+    _LIBCPP_ALWAYS_INLINE string_type falsename() const   {return do_falsename();}
+
+    static locale::id id;
+
+protected:
+    ~numpunct();
+    virtual char_type do_decimal_point() const;
+    virtual char_type do_thousands_sep() const;
+    virtual string do_grouping() const;
+    virtual string_type do_truename() const;
+    virtual string_type do_falsename() const;
+
+    char_type __decimal_point_;
+    char_type __thousands_sep_;
+    string __grouping_;
+};
+
+// template <class charT> class numpunct_byname
+
+template <class _CharT> class _LIBCPP_TYPE_VIS_ONLY numpunct_byname;
+
+template <>
+class _LIBCPP_TYPE_VIS numpunct_byname<char>
+: public numpunct<char>
+{
+public:
+    typedef char char_type;
+    typedef basic_string<char_type> string_type;
+
+    explicit numpunct_byname(const char* __nm, size_t __refs = 0);
+    explicit numpunct_byname(const string& __nm, size_t __refs = 0);
+
+protected:
+    ~numpunct_byname();
+
+private:
+    void __init(const char*);
+};
+
+template <>
+class _LIBCPP_TYPE_VIS numpunct_byname<wchar_t>
+: public numpunct<wchar_t>
+{
+public:
+    typedef wchar_t char_type;
+    typedef basic_string<char_type> string_type;
+
+    explicit numpunct_byname(const char* __nm, size_t __refs = 0);
+    explicit numpunct_byname(const string& __nm, size_t __refs = 0);
+
+protected:
+    ~numpunct_byname();
+
+private:
+    void __init(const char*);
+};
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP___LOCALE

diff --git a/libcxx/include/__mutex_base b/libcxx/include/__mutex_base
new file mode 100644
index 0000000..d5ece7c
--- /dev/null
+++ b/libcxx/include/__mutex_base

@@ -0,0 +1,407 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___MUTEX_BASE
+#define _LIBCPP___MUTEX_BASE
+
+#include <__config>
+#include <chrono>
+#include <system_error>
+#include <pthread.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#ifndef _LIBCPP_HAS_NO_THREADS
+
+class _LIBCPP_TYPE_VIS mutex
+{
+    pthread_mutex_t __m_;
+
+public:
+    _LIBCPP_INLINE_VISIBILITY
+#ifndef _LIBCPP_HAS_NO_CONSTEXPR
+     constexpr mutex() _NOEXCEPT : __m_(PTHREAD_MUTEX_INITIALIZER) {}
+#else
+     mutex() _NOEXCEPT {__m_ = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;}
+#endif
+     ~mutex();
+
+private:
+    mutex(const mutex&);// = delete;
+    mutex& operator=(const mutex&);// = delete;
+
+public:
+    void lock();
+    bool try_lock() _NOEXCEPT;
+    void unlock() _NOEXCEPT;
+
+    typedef pthread_mutex_t* native_handle_type;
+    _LIBCPP_INLINE_VISIBILITY native_handle_type native_handle() {return &__m_;}
+};
+
+struct _LIBCPP_TYPE_VIS defer_lock_t {};
+struct _LIBCPP_TYPE_VIS try_to_lock_t {};
+struct _LIBCPP_TYPE_VIS adopt_lock_t {};
+
+#if defined(_LIBCPP_HAS_NO_CONSTEXPR) || defined(_LIBCPP_BUILDING_MUTEX)
+
+extern const defer_lock_t  defer_lock;
+extern const try_to_lock_t try_to_lock;
+extern const adopt_lock_t  adopt_lock;
+
+#else
+
+constexpr defer_lock_t  defer_lock  = defer_lock_t();
+constexpr try_to_lock_t try_to_lock = try_to_lock_t();
+constexpr adopt_lock_t  adopt_lock  = adopt_lock_t();
+
+#endif
+
+template <class _Mutex>
+class _LIBCPP_TYPE_VIS_ONLY lock_guard
+{
+public:
+    typedef _Mutex mutex_type;
+
+private:
+    mutex_type& __m_;
+public:
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit lock_guard(mutex_type& __m)
+        : __m_(__m) {__m_.lock();}
+    _LIBCPP_INLINE_VISIBILITY
+    lock_guard(mutex_type& __m, adopt_lock_t)
+        : __m_(__m) {}
+    _LIBCPP_INLINE_VISIBILITY
+    ~lock_guard() {__m_.unlock();}
+
+private:
+    lock_guard(lock_guard const&);// = delete;
+    lock_guard& operator=(lock_guard const&);// = delete;
+};
+
+template <class _Mutex>
+class _LIBCPP_TYPE_VIS_ONLY unique_lock
+{
+public:
+    typedef _Mutex mutex_type;
+
+private:
+    mutex_type* __m_;
+    bool __owns_;
+
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    unique_lock() _NOEXCEPT : __m_(nullptr), __owns_(false) {}
+    _LIBCPP_INLINE_VISIBILITY
+    explicit unique_lock(mutex_type& __m)
+        : __m_(&__m), __owns_(true) {__m_->lock();}
+    _LIBCPP_INLINE_VISIBILITY
+    unique_lock(mutex_type& __m, defer_lock_t) _NOEXCEPT
+        : __m_(&__m), __owns_(false) {}
+    _LIBCPP_INLINE_VISIBILITY
+    unique_lock(mutex_type& __m, try_to_lock_t)
+        : __m_(&__m), __owns_(__m.try_lock()) {}
+    _LIBCPP_INLINE_VISIBILITY
+    unique_lock(mutex_type& __m, adopt_lock_t)
+        : __m_(&__m), __owns_(true) {}
+    template <class _Clock, class _Duration>
+    _LIBCPP_INLINE_VISIBILITY
+        unique_lock(mutex_type& __m, const chrono::time_point<_Clock, _Duration>& __t)
+            : __m_(&__m), __owns_(__m.try_lock_until(__t)) {}
+    template <class _Rep, class _Period>
+    _LIBCPP_INLINE_VISIBILITY
+        unique_lock(mutex_type& __m, const chrono::duration<_Rep, _Period>& __d)
+            : __m_(&__m), __owns_(__m.try_lock_for(__d)) {}
+    _LIBCPP_INLINE_VISIBILITY
+    ~unique_lock()
+    {
+        if (__owns_)
+            __m_->unlock();
+    }
+
+private:
+    unique_lock(unique_lock const&); // = delete;
+    unique_lock& operator=(unique_lock const&); // = delete;
+
+public:
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    unique_lock(unique_lock&& __u) _NOEXCEPT
+        : __m_(__u.__m_), __owns_(__u.__owns_)
+        {__u.__m_ = nullptr; __u.__owns_ = false;}
+    _LIBCPP_INLINE_VISIBILITY
+    unique_lock& operator=(unique_lock&& __u) _NOEXCEPT
+        {
+            if (__owns_)
+                __m_->unlock();
+            __m_ = __u.__m_;
+            __owns_ = __u.__owns_;
+            __u.__m_ = nullptr;
+            __u.__owns_ = false;
+            return *this;
+        }
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    void lock();
+    bool try_lock();
+
+    template <class _Rep, class _Period>
+        bool try_lock_for(const chrono::duration<_Rep, _Period>& __d);
+    template <class _Clock, class _Duration>
+        bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
+
+    void unlock();
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(unique_lock& __u) _NOEXCEPT
+    {
+        _VSTD::swap(__m_, __u.__m_);
+        _VSTD::swap(__owns_, __u.__owns_);
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    mutex_type* release() _NOEXCEPT
+    {
+        mutex_type* __m = __m_;
+        __m_ = nullptr;
+        __owns_ = false;
+        return __m;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool owns_lock() const _NOEXCEPT {return __owns_;}
+    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_EXPLICIT
+        operator bool () const _NOEXCEPT {return __owns_;}
+    _LIBCPP_INLINE_VISIBILITY
+    mutex_type* mutex() const _NOEXCEPT {return __m_;}
+};
+
+template <class _Mutex>
+void
+unique_lock<_Mutex>::lock()
+{
+    if (__m_ == nullptr)
+        __throw_system_error(EPERM, "unique_lock::lock: references null mutex");
+    if (__owns_)
+        __throw_system_error(EDEADLK, "unique_lock::lock: already locked");
+    __m_->lock();
+    __owns_ = true;
+}
+
+template <class _Mutex>
+bool
+unique_lock<_Mutex>::try_lock()
+{
+    if (__m_ == nullptr)
+        __throw_system_error(EPERM, "unique_lock::try_lock: references null mutex");
+    if (__owns_)
+        __throw_system_error(EDEADLK, "unique_lock::try_lock: already locked");
+    __owns_ = __m_->try_lock();
+    return __owns_;
+}
+
+template <class _Mutex>
+template <class _Rep, class _Period>
+bool
+unique_lock<_Mutex>::try_lock_for(const chrono::duration<_Rep, _Period>& __d)
+{
+    if (__m_ == nullptr)
+        __throw_system_error(EPERM, "unique_lock::try_lock_for: references null mutex");
+    if (__owns_)
+        __throw_system_error(EDEADLK, "unique_lock::try_lock_for: already locked");
+    __owns_ = __m_->try_lock_for(__d);
+    return __owns_;
+}
+
+template <class _Mutex>
+template <class _Clock, class _Duration>
+bool
+unique_lock<_Mutex>::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
+{
+    if (__m_ == nullptr)
+        __throw_system_error(EPERM, "unique_lock::try_lock_until: references null mutex");
+    if (__owns_)
+        __throw_system_error(EDEADLK, "unique_lock::try_lock_until: already locked");
+    __owns_ = __m_->try_lock_until(__t);
+    return __owns_;
+}
+
+template <class _Mutex>
+void
+unique_lock<_Mutex>::unlock()
+{
+    if (!__owns_)
+        __throw_system_error(EPERM, "unique_lock::unlock: not locked");
+    __m_->unlock();
+    __owns_ = false;
+}
+
+template <class _Mutex>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y) _NOEXCEPT
+    {__x.swap(__y);}
+
+//enum class cv_status
+_LIBCPP_DECLARE_STRONG_ENUM(cv_status)
+{
+    no_timeout,
+    timeout
+};
+_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(cv_status)
+
+class _LIBCPP_TYPE_VIS condition_variable
+{
+    pthread_cond_t __cv_;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+#ifndef _LIBCPP_HAS_NO_CONSTEXPR
+    constexpr condition_variable() : __cv_(PTHREAD_COND_INITIALIZER) {}
+#else
+    condition_variable() {__cv_ = (pthread_cond_t)PTHREAD_COND_INITIALIZER;}
+#endif
+    ~condition_variable();
+
+private:
+    condition_variable(const condition_variable&); // = delete;
+    condition_variable& operator=(const condition_variable&); // = delete;
+
+public:
+    void notify_one() _NOEXCEPT;
+    void notify_all() _NOEXCEPT;
+
+    void wait(unique_lock<mutex>& __lk) _NOEXCEPT;
+    template <class _Predicate>
+        void wait(unique_lock<mutex>& __lk, _Predicate __pred);
+
+    template <class _Clock, class _Duration>
+        cv_status
+        wait_until(unique_lock<mutex>& __lk,
+                   const chrono::time_point<_Clock, _Duration>& __t);
+
+    template <class _Clock, class _Duration, class _Predicate>
+        bool
+        wait_until(unique_lock<mutex>& __lk,
+                   const chrono::time_point<_Clock, _Duration>& __t,
+                   _Predicate __pred);
+
+    template <class _Rep, class _Period>
+        cv_status
+        wait_for(unique_lock<mutex>& __lk,
+                 const chrono::duration<_Rep, _Period>& __d);
+
+    template <class _Rep, class _Period, class _Predicate>
+        bool
+        wait_for(unique_lock<mutex>& __lk,
+                 const chrono::duration<_Rep, _Period>& __d,
+                 _Predicate __pred);
+
+    typedef pthread_cond_t* native_handle_type;
+    _LIBCPP_INLINE_VISIBILITY native_handle_type native_handle() {return &__cv_;}
+
+private:
+    void __do_timed_wait(unique_lock<mutex>& __lk,
+       chrono::time_point<chrono::system_clock, chrono::nanoseconds>) _NOEXCEPT;
+};
+#endif // !_LIBCPP_HAS_NO_THREADS
+
+template <class _To, class _Rep, class _Period>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    chrono::__is_duration<_To>::value,
+    _To
+>::type
+__ceil(chrono::duration<_Rep, _Period> __d)
+{
+    using namespace chrono;
+    _To __r = duration_cast<_To>(__d);
+    if (__r < __d)
+        ++__r;
+    return __r;
+}
+
+#ifndef _LIBCPP_HAS_NO_THREADS
+template <class _Predicate>
+void
+condition_variable::wait(unique_lock<mutex>& __lk, _Predicate __pred)
+{
+    while (!__pred())
+        wait(__lk);
+}
+
+template <class _Clock, class _Duration>
+cv_status
+condition_variable::wait_until(unique_lock<mutex>& __lk,
+                               const chrono::time_point<_Clock, _Duration>& __t)
+{
+    using namespace chrono;
+    wait_for(__lk, __t - _Clock::now());
+    return _Clock::now() < __t ? cv_status::no_timeout : cv_status::timeout;
+}
+
+template <class _Clock, class _Duration, class _Predicate>
+bool
+condition_variable::wait_until(unique_lock<mutex>& __lk,
+                   const chrono::time_point<_Clock, _Duration>& __t,
+                   _Predicate __pred)
+{
+    while (!__pred())
+    {
+        if (wait_until(__lk, __t) == cv_status::timeout)
+            return __pred();
+    }
+    return true;
+}
+
+template <class _Rep, class _Period>
+cv_status
+condition_variable::wait_for(unique_lock<mutex>& __lk,
+                             const chrono::duration<_Rep, _Period>& __d)
+{
+    using namespace chrono;
+    if (__d <= __d.zero())
+        return cv_status::timeout;
+    typedef time_point<system_clock, duration<long double, nano> > __sys_tpf;
+    typedef time_point<system_clock, nanoseconds> __sys_tpi;
+    __sys_tpf _Max = __sys_tpi::max();
+    system_clock::time_point __s_now = system_clock::now();
+    steady_clock::time_point __c_now = steady_clock::now();
+    if (_Max - __d > __s_now)
+        __do_timed_wait(__lk, __s_now + __ceil<nanoseconds>(__d));
+    else
+        __do_timed_wait(__lk, __sys_tpi::max());
+    return steady_clock::now() - __c_now < __d ? cv_status::no_timeout :
+                                                 cv_status::timeout;
+}
+
+template <class _Rep, class _Period, class _Predicate>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+condition_variable::wait_for(unique_lock<mutex>& __lk,
+                             const chrono::duration<_Rep, _Period>& __d,
+                             _Predicate __pred)
+{
+    return wait_until(__lk, chrono::steady_clock::now() + __d,
+                      _VSTD::move(__pred));
+}
+
+#endif // !_LIBCPP_HAS_NO_THREADS
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP___MUTEX_BASE

diff --git a/libcxx/include/__refstring b/libcxx/include/__refstring
new file mode 100644
index 0000000..61ccc75
--- /dev/null
+++ b/libcxx/include/__refstring

@@ -0,0 +1,139 @@
+//===------------------------ __refstring ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___REFSTRING
+#define _LIBCPP___REFSTRING
+
+#include <__config>
+#include <cstddef>
+#include <cstring>
+#ifdef __APPLE__
+#include <dlfcn.h>
+#include <mach-o/dyld.h>
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+class _LIBCPP_HIDDEN __libcpp_refstring
+{
+private:
+    const char* str_;
+
+    typedef int count_t;
+
+    struct _Rep_base
+    {
+        std::size_t len;
+        std::size_t cap;
+        count_t     count;
+    };
+
+    static
+    _Rep_base*
+    rep_from_data(const char *data_) _NOEXCEPT
+    {
+        char *data = const_cast<char *>(data_);
+        return reinterpret_cast<_Rep_base *>(data - sizeof(_Rep_base));
+    }
+    static
+    char *
+    data_from_rep(_Rep_base *rep) _NOEXCEPT
+    {
+        char *data = reinterpret_cast<char *>(rep);
+        return data + sizeof(*rep);
+    }
+
+#ifdef __APPLE__
+    static
+    const char*
+    compute_gcc_empty_string_storage() _NOEXCEPT
+    {
+        void* handle = dlopen("/usr/lib/libstdc++.6.dylib", RTLD_NOLOAD);
+        if (handle == nullptr)
+            return nullptr;
+        void* sym = dlsym(handle, "_ZNSs4_Rep20_S_empty_rep_storageE");
+        if (sym == nullptr)
+            return nullptr;
+        return data_from_rep(reinterpret_cast<_Rep_base *>(sym));
+    }
+
+    static
+    const char*
+    get_gcc_empty_string_storage() _NOEXCEPT
+    {
+        static const char* p = compute_gcc_empty_string_storage();
+        return p;
+    }
+
+    bool
+    uses_refcount() const
+    {
+        return str_ != get_gcc_empty_string_storage();
+    }
+#else
+    bool
+    uses_refcount() const
+    {
+        return true;
+    }
+#endif
+
+public:
+    explicit __libcpp_refstring(const char* msg) {
+        std::size_t len = strlen(msg);
+        _Rep_base* rep = static_cast<_Rep_base *>(::operator new(sizeof(*rep) + len + 1));
+        rep->len = len;
+        rep->cap = len;
+        rep->count = 0;
+        char *data = data_from_rep(rep);
+        std::memcpy(data, msg, len + 1);
+        str_ = data;
+    }
+
+    __libcpp_refstring(const __libcpp_refstring& s) _NOEXCEPT : str_(s.str_)
+    {
+        if (uses_refcount())
+            __sync_add_and_fetch(&rep_from_data(str_)->count, 1);
+    }
+
+    __libcpp_refstring& operator=(const __libcpp_refstring& s) _NOEXCEPT
+    {
+        bool adjust_old_count = uses_refcount();
+        struct _Rep_base *old_rep = rep_from_data(str_);
+        str_ = s.str_;
+        if (uses_refcount())
+            __sync_add_and_fetch(&rep_from_data(str_)->count, 1);
+        if (adjust_old_count)
+        {
+            if (__sync_add_and_fetch(&old_rep->count, count_t(-1)) < 0)
+            {
+                ::operator delete(old_rep);
+            }
+        }
+        return *this;
+    }
+
+    ~__libcpp_refstring()
+    {
+        if (uses_refcount())
+        {
+            _Rep_base* rep = rep_from_data(str_);
+            if (__sync_add_and_fetch(&rep->count, count_t(-1)) < 0)
+            {
+                ::operator delete(rep);
+            }
+        }
+    }
+
+    const char* c_str() const _NOEXCEPT {return str_;}
+};
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif //_LIBCPP___REFSTRING

diff --git a/libcxx/include/__split_buffer b/libcxx/include/__split_buffer
new file mode 100644
index 0000000..727b1b6
--- /dev/null
+++ b/libcxx/include/__split_buffer

@@ -0,0 +1,635 @@
+// -*- C++ -*-
+#ifndef _LIBCPP_SPLIT_BUFFER
+#define _LIBCPP_SPLIT_BUFFER
+
+#include <__config>
+#include <type_traits>
+#include <algorithm>
+
+#include <__undef_min_max>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <bool>
+class __split_buffer_common
+{
+protected:
+    void __throw_length_error() const;
+    void __throw_out_of_range() const;
+};
+
+template <class _Tp, class _Allocator = allocator<_Tp> >
+struct __split_buffer
+    : private __split_buffer_common<true>
+{
+private:
+    __split_buffer(const __split_buffer&);
+    __split_buffer& operator=(const __split_buffer&);
+public:
+    typedef _Tp                                             value_type;
+    typedef _Allocator                                      allocator_type;
+    typedef typename remove_reference<allocator_type>::type __alloc_rr;
+    typedef allocator_traits<__alloc_rr>                    __alloc_traits;
+    typedef value_type&                                     reference;
+    typedef const value_type&                               const_reference;
+    typedef typename __alloc_traits::size_type              size_type;
+    typedef typename __alloc_traits::difference_type        difference_type;
+    typedef typename __alloc_traits::pointer                pointer;
+    typedef typename __alloc_traits::const_pointer          const_pointer;
+    typedef pointer                                         iterator;
+    typedef const_pointer                                   const_iterator;
+
+    pointer                                         __first_;
+    pointer                                         __begin_;
+    pointer                                         __end_;
+    __compressed_pair<pointer, allocator_type> __end_cap_;
+
+    typedef typename add_lvalue_reference<allocator_type>::type __alloc_ref;
+    typedef typename add_lvalue_reference<allocator_type>::type __alloc_const_ref;
+
+    _LIBCPP_INLINE_VISIBILITY __alloc_rr&           __alloc() _NOEXCEPT         {return __end_cap_.second();}
+    _LIBCPP_INLINE_VISIBILITY const __alloc_rr&     __alloc() const _NOEXCEPT   {return __end_cap_.second();}
+    _LIBCPP_INLINE_VISIBILITY pointer&              __end_cap() _NOEXCEPT       {return __end_cap_.first();}
+    _LIBCPP_INLINE_VISIBILITY const pointer&        __end_cap() const _NOEXCEPT {return __end_cap_.first();}
+
+    __split_buffer()
+        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value);
+    explicit __split_buffer(__alloc_rr& __a);
+    explicit __split_buffer(const __alloc_rr& __a);
+    __split_buffer(size_type __cap, size_type __start, __alloc_rr& __a);
+    ~__split_buffer();
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    __split_buffer(__split_buffer&& __c)
+        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
+    __split_buffer(__split_buffer&& __c, const __alloc_rr& __a);
+    __split_buffer& operator=(__split_buffer&& __c)
+        _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value &&
+                is_nothrow_move_assignable<allocator_type>::value) ||
+               !__alloc_traits::propagate_on_container_move_assignment::value);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY       iterator begin() _NOEXCEPT       {return __begin_;}
+    _LIBCPP_INLINE_VISIBILITY const_iterator begin() const _NOEXCEPT {return __begin_;}
+    _LIBCPP_INLINE_VISIBILITY       iterator end() _NOEXCEPT         {return __end_;}
+    _LIBCPP_INLINE_VISIBILITY const_iterator end() const _NOEXCEPT   {return __end_;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void clear() _NOEXCEPT
+        {__destruct_at_end(__begin_);}
+    _LIBCPP_INLINE_VISIBILITY size_type size() const {return static_cast<size_type>(__end_ - __begin_);}
+    _LIBCPP_INLINE_VISIBILITY bool empty()     const {return __end_ == __begin_;}
+    _LIBCPP_INLINE_VISIBILITY size_type capacity() const {return static_cast<size_type>(__end_cap() - __first_);}
+    _LIBCPP_INLINE_VISIBILITY size_type __front_spare() const {return static_cast<size_type>(__begin_ - __first_);}
+    _LIBCPP_INLINE_VISIBILITY size_type __back_spare() const {return static_cast<size_type>(__end_cap() - __end_);}
+
+    _LIBCPP_INLINE_VISIBILITY       reference front()       {return *__begin_;}
+    _LIBCPP_INLINE_VISIBILITY const_reference front() const {return *__begin_;}
+    _LIBCPP_INLINE_VISIBILITY       reference back()        {return *(__end_ - 1);}
+    _LIBCPP_INLINE_VISIBILITY const_reference back() const  {return *(__end_ - 1);}
+
+    void reserve(size_type __n);
+    void shrink_to_fit() _NOEXCEPT;
+    void push_front(const_reference __x);
+    _LIBCPP_INLINE_VISIBILITY void push_back(const_reference __x);
+#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+    void push_front(value_type&& __x);
+    void push_back(value_type&& __x);
+#if !defined(_LIBCPP_HAS_NO_VARIADICS)
+    template <class... _Args>
+        void emplace_back(_Args&&... __args);
+#endif  // !defined(_LIBCPP_HAS_NO_VARIADICS)
+#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+
+    _LIBCPP_INLINE_VISIBILITY void pop_front() {__destruct_at_begin(__begin_+1);}
+    _LIBCPP_INLINE_VISIBILITY void pop_back() {__destruct_at_end(__end_-1);}
+
+    void __construct_at_end(size_type __n);
+    void __construct_at_end(size_type __n, const_reference __x);
+    template <class _InputIter>
+        typename enable_if
+        <
+            __is_input_iterator<_InputIter>::value &&
+           !__is_forward_iterator<_InputIter>::value,
+            void
+        >::type
+        __construct_at_end(_InputIter __first, _InputIter __last);
+    template <class _ForwardIterator>
+        typename enable_if
+        <
+            __is_forward_iterator<_ForwardIterator>::value,
+            void
+        >::type
+        __construct_at_end(_ForwardIterator __first, _ForwardIterator __last);
+
+    _LIBCPP_INLINE_VISIBILITY void __destruct_at_begin(pointer __new_begin)
+        {__destruct_at_begin(__new_begin, is_trivially_destructible<value_type>());}
+        void __destruct_at_begin(pointer __new_begin, false_type);
+        void __destruct_at_begin(pointer __new_begin, true_type);
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __destruct_at_end(pointer __new_last) _NOEXCEPT
+        {__destruct_at_end(__new_last, false_type());}
+    _LIBCPP_INLINE_VISIBILITY
+        void __destruct_at_end(pointer __new_last, false_type) _NOEXCEPT;
+    _LIBCPP_INLINE_VISIBILITY
+        void __destruct_at_end(pointer __new_last, true_type) _NOEXCEPT;
+
+    void swap(__split_buffer& __x)
+        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value||
+                   __is_nothrow_swappable<__alloc_rr>::value);
+
+    bool __invariants() const;
+
+private:
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__split_buffer& __c, true_type)
+        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
+        {
+            __alloc() = _VSTD::move(__c.__alloc());
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__split_buffer&, false_type) _NOEXCEPT
+        {}
+};
+
+template <class _Tp, class _Allocator>
+bool
+__split_buffer<_Tp, _Allocator>::__invariants() const
+{
+    if (__first_ == nullptr)
+    {
+        if (__begin_ != nullptr)
+            return false;
+        if (__end_ != nullptr)
+            return false;
+        if (__end_cap() != nullptr)
+            return false;
+    }
+    else
+    {
+        if (__begin_ < __first_)
+            return false;
+        if (__end_ < __begin_)
+            return false;
+        if (__end_cap() < __end_)
+            return false;
+    }
+    return true;
+}
+
+//  Default constructs __n objects starting at __end_
+//  throws if construction throws
+//  Precondition:  __n > 0
+//  Precondition:  size() + __n <= capacity()
+//  Postcondition:  size() == size() + __n
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n)
+{
+    __alloc_rr& __a = this->__alloc();
+    do
+    {
+        __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(this->__end_));
+        ++this->__end_;
+        --__n;
+    } while (__n > 0);
+}
+
+//  Copy constructs __n objects starting at __end_ from __x
+//  throws if construction throws
+//  Precondition:  __n > 0
+//  Precondition:  size() + __n <= capacity()
+//  Postcondition:  size() == old size() + __n
+//  Postcondition:  [i] == __x for all i in [size() - __n, __n)
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n, const_reference __x)
+{
+    __alloc_rr& __a = this->__alloc();
+    do
+    {
+        __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(this->__end_), __x);
+        ++this->__end_;
+        --__n;
+    } while (__n > 0);
+}
+
+template <class _Tp, class _Allocator>
+template <class _InputIter>
+typename enable_if
+<
+     __is_input_iterator<_InputIter>::value &&
+    !__is_forward_iterator<_InputIter>::value,
+    void
+>::type
+__split_buffer<_Tp, _Allocator>::__construct_at_end(_InputIter __first, _InputIter __last)
+{
+    __alloc_rr& __a = this->__alloc();
+    for (; __first != __last; ++__first)
+    {
+        if (__end_ == __end_cap())
+        {
+            size_type __old_cap = __end_cap() - __first_;
+            size_type __new_cap = _VSTD::max<size_type>(2 * __old_cap, 8);
+            __split_buffer __buf(__new_cap, 0, __a);
+            for (pointer __p = __begin_; __p != __end_; ++__p, ++__buf.__end_)
+                __alloc_traits::construct(__buf.__alloc(),
+                        _VSTD::__to_raw_pointer(__buf.__end_), _VSTD::move(*__p));
+            swap(__buf);
+        }
+        __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(this->__end_), *__first);
+        ++this->__end_;
+    }
+}
+
+template <class _Tp, class _Allocator>
+template <class _ForwardIterator>
+typename enable_if
+<
+    __is_forward_iterator<_ForwardIterator>::value,
+    void
+>::type
+__split_buffer<_Tp, _Allocator>::__construct_at_end(_ForwardIterator __first, _ForwardIterator __last)
+{
+    __alloc_rr& __a = this->__alloc();
+    for (; __first != __last; ++__first)
+    {
+        __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(this->__end_), *__first);
+        ++this->__end_;
+    }
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, false_type)
+{
+    while (__begin_ != __new_begin)
+        __alloc_traits::destroy(__alloc(), __to_raw_pointer(__begin_++));
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, true_type)
+{
+    __begin_ = __new_begin;
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, false_type) _NOEXCEPT
+{
+    while (__new_last != __end_)
+        __alloc_traits::destroy(__alloc(), __to_raw_pointer(--__end_));
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, true_type) _NOEXCEPT
+{
+    __end_ = __new_last;
+}
+
+template <class _Tp, class _Allocator>
+__split_buffer<_Tp, _Allocator>::__split_buffer(size_type __cap, size_type __start, __alloc_rr& __a)
+    : __end_cap_(nullptr, __a)
+{
+    __first_ = __cap != 0 ? __alloc_traits::allocate(__alloc(), __cap) : nullptr;
+    __begin_ = __end_ = __first_ + __start;
+    __end_cap() = __first_ + __cap;
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+__split_buffer<_Tp, _Allocator>::__split_buffer()
+    _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
+    : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr)
+{
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+__split_buffer<_Tp, _Allocator>::__split_buffer(__alloc_rr& __a)
+    : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a)
+{
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+__split_buffer<_Tp, _Allocator>::__split_buffer(const __alloc_rr& __a)
+    : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a)
+{
+}
+
+template <class _Tp, class _Allocator>
+__split_buffer<_Tp, _Allocator>::~__split_buffer()
+{
+    clear();
+    if (__first_)
+        __alloc_traits::deallocate(__alloc(), __first_, capacity());
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Allocator>
+__split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c)
+    _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
+    : __first_(_VSTD::move(__c.__first_)),
+      __begin_(_VSTD::move(__c.__begin_)),
+      __end_(_VSTD::move(__c.__end_)),
+      __end_cap_(_VSTD::move(__c.__end_cap_))
+{
+    __c.__first_ = nullptr;
+    __c.__begin_ = nullptr;
+    __c.__end_ = nullptr;
+    __c.__end_cap() = nullptr;
+}
+
+template <class _Tp, class _Allocator>
+__split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c, const __alloc_rr& __a)
+    : __end_cap_(__a)
+{
+    if (__a == __c.__alloc())
+    {
+        __first_ = __c.__first_;
+        __begin_ = __c.__begin_;
+        __end_ = __c.__end_;
+        __end_cap() = __c.__end_cap();
+        __c.__first_ = nullptr;
+        __c.__begin_ = nullptr;
+        __c.__end_ = nullptr;
+        __c.__end_cap() = nullptr;
+    }
+    else
+    {
+        size_type __cap = __c.size();
+        __first_ = __alloc_traits::allocate(__alloc(), __cap);
+        __begin_ = __end_ = __first_;
+        __end_cap() = __first_ + __cap;
+        typedef move_iterator<iterator> _Ip;
+        __construct_at_end(_Ip(__c.begin()), _Ip(__c.end()));
+    }
+}
+
+template <class _Tp, class _Allocator>
+__split_buffer<_Tp, _Allocator>&
+__split_buffer<_Tp, _Allocator>::operator=(__split_buffer&& __c)
+    _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value &&
+                is_nothrow_move_assignable<allocator_type>::value) ||
+               !__alloc_traits::propagate_on_container_move_assignment::value)
+{
+    clear();
+    shrink_to_fit();
+    __first_ = __c.__first_;
+    __begin_ = __c.__begin_;
+    __end_ = __c.__end_;
+    __end_cap() = __c.__end_cap();
+    __move_assign_alloc(__c,
+        integral_constant<bool,
+                          __alloc_traits::propagate_on_container_move_assignment::value>());
+    __c.__first_ = __c.__begin_ = __c.__end_ = __c.__end_cap() = nullptr;
+    return *this;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::swap(__split_buffer& __x)
+        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value||
+                   __is_nothrow_swappable<__alloc_rr>::value)
+{
+    _VSTD::swap(__first_, __x.__first_);
+    _VSTD::swap(__begin_, __x.__begin_);
+    _VSTD::swap(__end_, __x.__end_);
+    _VSTD::swap(__end_cap(), __x.__end_cap());
+    __swap_allocator(__alloc(), __x.__alloc());
+}
+
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::reserve(size_type __n)
+{
+    if (__n < capacity())
+    {
+        __split_buffer<value_type, __alloc_rr&> __t(__n, 0, __alloc());
+        __t.__construct_at_end(move_iterator<pointer>(__begin_),
+                               move_iterator<pointer>(__end_));
+        _VSTD::swap(__first_, __t.__first_);
+        _VSTD::swap(__begin_, __t.__begin_);
+        _VSTD::swap(__end_, __t.__end_);
+        _VSTD::swap(__end_cap(), __t.__end_cap());
+    }
+}
+
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT
+{
+    if (capacity() > size())
+    {
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        try
+        {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            __split_buffer<value_type, __alloc_rr&> __t(size(), 0, __alloc());
+            __t.__construct_at_end(move_iterator<pointer>(__begin_),
+                                   move_iterator<pointer>(__end_));
+            __t.__end_ = __t.__begin_ + (__end_ - __begin_);
+            _VSTD::swap(__first_, __t.__first_);
+            _VSTD::swap(__begin_, __t.__begin_);
+            _VSTD::swap(__end_, __t.__end_);
+            _VSTD::swap(__end_cap(), __t.__end_cap());
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        }
+        catch (...)
+        {
+        }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    }
+}
+
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::push_front(const_reference __x)
+{
+    if (__begin_ == __first_)
+    {
+        if (__end_ < __end_cap())
+        {
+            difference_type __d = __end_cap() - __end_;
+            __d = (__d + 1) / 2;
+            __begin_ = _VSTD::move_backward(__begin_, __end_, __end_ + __d);
+            __end_ += __d;
+        }
+        else
+        {
+            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
+            __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc());
+            __t.__construct_at_end(move_iterator<pointer>(__begin_),
+                                   move_iterator<pointer>(__end_));
+            _VSTD::swap(__first_, __t.__first_);
+            _VSTD::swap(__begin_, __t.__begin_);
+            _VSTD::swap(__end_, __t.__end_);
+            _VSTD::swap(__end_cap(), __t.__end_cap());
+        }
+    }
+    __alloc_traits::construct(__alloc(), _VSTD::__to_raw_pointer(__begin_-1), __x);
+    --__begin_;
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::push_front(value_type&& __x)
+{
+    if (__begin_ == __first_)
+    {
+        if (__end_ < __end_cap())
+        {
+            difference_type __d = __end_cap() - __end_;
+            __d = (__d + 1) / 2;
+            __begin_ = _VSTD::move_backward(__begin_, __end_, __end_ + __d);
+            __end_ += __d;
+        }
+        else
+        {
+            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
+            __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc());
+            __t.__construct_at_end(move_iterator<pointer>(__begin_),
+                                   move_iterator<pointer>(__end_));
+            _VSTD::swap(__first_, __t.__first_);
+            _VSTD::swap(__begin_, __t.__begin_);
+            _VSTD::swap(__end_, __t.__end_);
+            _VSTD::swap(__end_cap(), __t.__end_cap());
+        }
+    }
+    __alloc_traits::construct(__alloc(), _VSTD::__to_raw_pointer(__begin_-1),
+            _VSTD::move(__x));
+    --__begin_;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__split_buffer<_Tp, _Allocator>::push_back(const_reference __x)
+{
+    if (__end_ == __end_cap())
+    {
+        if (__begin_ > __first_)
+        {
+            difference_type __d = __begin_ - __first_;
+            __d = (__d + 1) / 2;
+            __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d);
+            __begin_ -= __d;
+        }
+        else
+        {
+            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
+            __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc());
+            __t.__construct_at_end(move_iterator<pointer>(__begin_),
+                                   move_iterator<pointer>(__end_));
+            _VSTD::swap(__first_, __t.__first_);
+            _VSTD::swap(__begin_, __t.__begin_);
+            _VSTD::swap(__end_, __t.__end_);
+            _VSTD::swap(__end_cap(), __t.__end_cap());
+        }
+    }
+    __alloc_traits::construct(__alloc(), _VSTD::__to_raw_pointer(__end_), __x);
+    ++__end_;
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Allocator>
+void
+__split_buffer<_Tp, _Allocator>::push_back(value_type&& __x)
+{
+    if (__end_ == __end_cap())
+    {
+        if (__begin_ > __first_)
+        {
+            difference_type __d = __begin_ - __first_;
+            __d = (__d + 1) / 2;
+            __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d);
+            __begin_ -= __d;
+        }
+        else
+        {
+            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
+            __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc());
+            __t.__construct_at_end(move_iterator<pointer>(__begin_),
+                                   move_iterator<pointer>(__end_));
+            _VSTD::swap(__first_, __t.__first_);
+            _VSTD::swap(__begin_, __t.__begin_);
+            _VSTD::swap(__end_, __t.__end_);
+            _VSTD::swap(__end_cap(), __t.__end_cap());
+        }
+    }
+    __alloc_traits::construct(__alloc(), _VSTD::__to_raw_pointer(__end_),
+            _VSTD::move(__x));
+    ++__end_;
+}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Allocator>
+template <class... _Args>
+void
+__split_buffer<_Tp, _Allocator>::emplace_back(_Args&&... __args)
+{
+    if (__end_ == __end_cap())
+    {
+        if (__begin_ > __first_)
+        {
+            difference_type __d = __begin_ - __first_;
+            __d = (__d + 1) / 2;
+            __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d);
+            __begin_ -= __d;
+        }
+        else
+        {
+            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
+            __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc());
+            __t.__construct_at_end(move_iterator<pointer>(__begin_),
+                                   move_iterator<pointer>(__end_));
+            _VSTD::swap(__first_, __t.__first_);
+            _VSTD::swap(__begin_, __t.__begin_);
+            _VSTD::swap(__end_, __t.__end_);
+            _VSTD::swap(__end_cap(), __t.__end_cap());
+        }
+    }
+    __alloc_traits::construct(__alloc(), _VSTD::__to_raw_pointer(__end_),
+                              _VSTD::forward<_Args>(__args)...);
+    ++__end_;
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(__split_buffer<_Tp, _Allocator>& __x, __split_buffer<_Tp, _Allocator>& __y)
+        _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
+{
+    __x.swap(__y);
+}
+
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_SPLIT_BUFFER

diff --git a/libcxx/include/__sso_allocator b/libcxx/include/__sso_allocator
new file mode 100644
index 0000000..ca3b937
--- /dev/null
+++ b/libcxx/include/__sso_allocator

@@ -0,0 +1,79 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___SSO_ALLOCATOR
+#define _LIBCPP___SSO_ALLOCATOR
+
+#include <__config>
+#include <type_traits>
+#include <new>
+
+#include <__undef___deallocate>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp, size_t _Np> class _LIBCPP_HIDDEN __sso_allocator;
+
+template <size_t _Np>
+class _LIBCPP_HIDDEN __sso_allocator<void, _Np>
+{
+public:
+    typedef const void*       const_pointer;
+    typedef void              value_type;
+};
+
+template <class _Tp, size_t _Np>
+class _LIBCPP_HIDDEN __sso_allocator
+{
+    typename aligned_storage<sizeof(_Tp) * _Np>::type buf_;
+    bool __allocated_;
+public:
+    typedef size_t            size_type;
+    typedef _Tp*              pointer;
+    typedef _Tp               value_type;
+
+    _LIBCPP_INLINE_VISIBILITY __sso_allocator() throw() : __allocated_(false) {}
+    _LIBCPP_INLINE_VISIBILITY __sso_allocator(const __sso_allocator&) throw() : __allocated_(false) {}
+    template <class _Up> _LIBCPP_INLINE_VISIBILITY __sso_allocator(const __sso_allocator<_Up, _Np>&) throw()
+         : __allocated_(false) {}
+private:
+    __sso_allocator& operator=(const __sso_allocator&);
+public:
+    _LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n, typename __sso_allocator<void, _Np>::const_pointer = 0)
+    {
+        if (!__allocated_ && __n <= _Np)
+        {
+            __allocated_ = true;
+            return (pointer)&buf_;
+        }
+        return static_cast<pointer>(_VSTD::__allocate(__n * sizeof(_Tp)));
+    }
+    _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type)
+    {
+        if (__p == (pointer)&buf_)
+            __allocated_ = false;
+        else
+            _VSTD::__deallocate(__p);
+    }
+    _LIBCPP_INLINE_VISIBILITY size_type max_size() const throw() {return size_type(~0) / sizeof(_Tp);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator==(__sso_allocator& __a) const {return &buf_ == &__a.buf_;}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(__sso_allocator& __a) const {return &buf_ != &__a.buf_;}
+};
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP___SSO_ALLOCATOR

diff --git a/libcxx/include/__std_stream b/libcxx/include/__std_stream
new file mode 100644
index 0000000..f867cd2
--- /dev/null
+++ b/libcxx/include/__std_stream

@@ -0,0 +1,358 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___STD_STREAM
+#define _LIBCPP___STD_STREAM
+
+#include <__config>
+#include <ostream>
+#include <istream>
+#include <__locale>
+#include <cstdio>
+
+#include <__undef_min_max>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+static const int __limit = 8;
+
+// __stdinbuf
+
+template <class _CharT>
+class _LIBCPP_HIDDEN __stdinbuf
+    : public basic_streambuf<_CharT, char_traits<_CharT> >
+{
+public:
+    typedef _CharT                           char_type;
+    typedef char_traits<char_type>           traits_type;
+    typedef typename traits_type::int_type   int_type;
+    typedef typename traits_type::pos_type   pos_type;
+    typedef typename traits_type::off_type   off_type;
+    typedef typename traits_type::state_type state_type;
+
+    __stdinbuf(FILE* __fp, state_type* __st);
+
+protected:
+    virtual int_type underflow();
+    virtual int_type uflow();
+    virtual int_type pbackfail(int_type __c = traits_type::eof());
+    virtual void imbue(const locale& __loc);
+
+private:
+
+    FILE* __file_;
+    const codecvt<char_type, char, state_type>* __cv_;
+    state_type* __st_;
+    int __encoding_;
+    int_type __last_consumed_;
+    bool __last_consumed_is_next_;
+    bool __always_noconv_;
+
+    __stdinbuf(const __stdinbuf&);
+    __stdinbuf& operator=(const __stdinbuf&);
+
+    int_type __getchar(bool __consume);
+};
+
+template <class _CharT>
+__stdinbuf<_CharT>::__stdinbuf(FILE* __fp, state_type* __st)
+    : __file_(__fp),
+      __st_(__st),
+      __last_consumed_(traits_type::eof()),
+      __last_consumed_is_next_(false)
+{
+    imbue(this->getloc());
+}
+
+template <class _CharT>
+void
+__stdinbuf<_CharT>::imbue(const locale& __loc)
+{
+    __cv_ = &use_facet<codecvt<char_type, char, state_type> >(__loc);
+    __encoding_ = __cv_->encoding();
+    __always_noconv_ = __cv_->always_noconv();
+    if (__encoding_ > __limit)
+        __throw_runtime_error("unsupported locale for standard input");
+}
+
+template <class _CharT>
+typename __stdinbuf<_CharT>::int_type
+__stdinbuf<_CharT>::underflow()
+{
+    return __getchar(false);
+}
+
+template <class _CharT>
+typename __stdinbuf<_CharT>::int_type
+__stdinbuf<_CharT>::uflow()
+{
+    return __getchar(true);
+}
+
+template <class _CharT>
+typename __stdinbuf<_CharT>::int_type
+__stdinbuf<_CharT>::__getchar(bool __consume)
+{
+    if (__last_consumed_is_next_)
+    {
+        int_type __result = __last_consumed_;
+        if (__consume)
+        {
+            __last_consumed_ = traits_type::eof();
+            __last_consumed_is_next_ = false;
+        }
+        return __result;
+    }
+    char __extbuf[__limit];
+    int __nread = _VSTD::max(1, __encoding_);
+    for (int __i = 0; __i < __nread; ++__i)
+    {
+        int __c = getc(__file_);
+        if (__c == EOF)
+            return traits_type::eof();
+        __extbuf[__i] = static_cast<char>(__c);
+    }
+    char_type __1buf;
+    if (__always_noconv_)
+        __1buf = static_cast<char_type>(__extbuf[0]);
+    else
+    {
+        const char* __enxt;
+        char_type* __inxt;
+        codecvt_base::result __r;
+        do
+        {
+            state_type __sv_st = *__st_;
+            __r = __cv_->in(*__st_, __extbuf, __extbuf + __nread, __enxt,
+                                   &__1buf, &__1buf + 1, __inxt);
+            switch (__r)
+            {
+            case _VSTD::codecvt_base::ok:
+                break;
+            case codecvt_base::partial:
+                *__st_ = __sv_st;
+                if (__nread == sizeof(__extbuf))
+                    return traits_type::eof();
+                {
+                    int __c = getc(__file_);
+                    if (__c == EOF)
+                        return traits_type::eof();
+                    __extbuf[__nread] = static_cast<char>(__c);
+                }
+                ++__nread;
+                break;
+            case codecvt_base::error:
+                return traits_type::eof();
+            case _VSTD::codecvt_base::noconv:
+                __1buf = static_cast<char_type>(__extbuf[0]);
+                break;
+            }
+        } while (__r == _VSTD::codecvt_base::partial);
+    }
+    if (!__consume)
+    {
+        for (int __i = __nread; __i > 0;)
+        {
+            if (ungetc(traits_type::to_int_type(__extbuf[--__i]), __file_) == EOF)
+                return traits_type::eof();
+        }
+    }
+    else
+        __last_consumed_ = traits_type::to_int_type(__1buf);
+    return traits_type::to_int_type(__1buf);
+}
+
+template <class _CharT>
+typename __stdinbuf<_CharT>::int_type
+__stdinbuf<_CharT>::pbackfail(int_type __c)
+{
+    if (traits_type::eq_int_type(__c, traits_type::eof()))
+    {
+        if (!__last_consumed_is_next_)
+        {
+            __c = __last_consumed_;
+            __last_consumed_is_next_ = !traits_type::eq_int_type(__last_consumed_,
+                                                                 traits_type::eof());
+        }
+        return __c;
+    }
+    if (__last_consumed_is_next_)
+    {
+        char __extbuf[__limit];
+        char* __enxt;
+        const char_type __ci = traits_type::to_char_type(__last_consumed_);
+        const char_type* __inxt;
+        switch (__cv_->out(*__st_, &__ci, &__ci + 1, __inxt,
+                                  __extbuf, __extbuf + sizeof(__extbuf), __enxt))
+        {
+        case _VSTD::codecvt_base::ok:
+            break;
+        case _VSTD::codecvt_base::noconv:
+            __extbuf[0] = static_cast<char>(__last_consumed_);
+            __enxt = __extbuf + 1;
+            break;
+        case codecvt_base::partial:
+        case codecvt_base::error:
+            return traits_type::eof();
+        }
+        while (__enxt > __extbuf)
+            if (ungetc(*--__enxt, __file_) == EOF)
+                return traits_type::eof();
+    }
+    __last_consumed_ = __c;
+    __last_consumed_is_next_ = true;
+    return __c;
+}
+
+// __stdoutbuf
+
+template <class _CharT>
+class _LIBCPP_HIDDEN __stdoutbuf
+    : public basic_streambuf<_CharT, char_traits<_CharT> >
+{
+public:
+    typedef _CharT                           char_type;
+    typedef char_traits<char_type>           traits_type;
+    typedef typename traits_type::int_type   int_type;
+    typedef typename traits_type::pos_type   pos_type;
+    typedef typename traits_type::off_type   off_type;
+    typedef typename traits_type::state_type state_type;
+
+    __stdoutbuf(FILE* __fp, state_type* __st);
+
+protected:
+    virtual int_type overflow (int_type __c = traits_type::eof());
+    virtual streamsize xsputn(const char_type* __s, streamsize __n);
+    virtual int sync();
+    virtual void imbue(const locale& __loc);
+
+private:
+    FILE* __file_;
+    const codecvt<char_type, char, state_type>* __cv_;
+    state_type* __st_;
+    bool __always_noconv_;
+
+    __stdoutbuf(const __stdoutbuf&);
+    __stdoutbuf& operator=(const __stdoutbuf&);
+};
+
+template <class _CharT>
+__stdoutbuf<_CharT>::__stdoutbuf(FILE* __fp, state_type* __st)
+    : __file_(__fp),
+      __cv_(&use_facet<codecvt<char_type, char, state_type> >(this->getloc())),
+      __st_(__st),
+      __always_noconv_(__cv_->always_noconv())
+{
+}
+
+template <class _CharT>
+typename __stdoutbuf<_CharT>::int_type
+__stdoutbuf<_CharT>::overflow(int_type __c)
+{
+    char __extbuf[__limit];
+    char_type __1buf;
+    if (!traits_type::eq_int_type(__c, traits_type::eof()))
+    {
+        __1buf = traits_type::to_char_type(__c);
+        if (__always_noconv_)
+        {
+            if (fwrite(&__1buf, sizeof(char_type), 1, __file_) != 1)
+                return traits_type::eof();
+        }
+        else
+        {
+            char* __extbe = __extbuf;
+            codecvt_base::result __r;
+            char_type* pbase = &__1buf;
+            char_type* pptr = pbase + 1;
+            do
+            {
+                const char_type* __e;
+                __r = __cv_->out(*__st_, pbase, pptr, __e,
+                                        __extbuf,
+                                        __extbuf + sizeof(__extbuf),
+                                        __extbe);
+                if (__e == pbase)
+                    return traits_type::eof();
+                if (__r == codecvt_base::noconv)
+                {
+                    if (fwrite(pbase, 1, 1, __file_) != 1)
+                        return traits_type::eof();
+                }
+                else if (__r == codecvt_base::ok || __r == codecvt_base::partial)
+                {
+                    size_t __nmemb = static_cast<size_t>(__extbe - __extbuf);
+                    if (fwrite(__extbuf, 1, __nmemb, __file_) != __nmemb)
+                        return traits_type::eof();
+                    if (__r == codecvt_base::partial)
+                    {
+                        pbase = (char_type*)__e;
+                    }
+                }
+                else
+                    return traits_type::eof();
+            } while (__r == codecvt_base::partial);
+        }
+    }
+    return traits_type::not_eof(__c);
+}
+
+template <class _CharT>
+streamsize
+__stdoutbuf<_CharT>::xsputn(const char_type* __s, streamsize __n)
+{
+    if (__always_noconv_)
+        return fwrite(__s, sizeof(char_type), __n, __file_);
+    streamsize __i = 0;
+    for (; __i < __n; ++__i, ++__s)
+        if (overflow(traits_type::to_int_type(*__s)) == traits_type::eof())
+            break;
+    return __i;
+}
+
+template <class _CharT>
+int
+__stdoutbuf<_CharT>::sync()
+{
+    char __extbuf[__limit];
+    codecvt_base::result __r;
+    do
+    {
+        char* __extbe;
+        __r = __cv_->unshift(*__st_, __extbuf,
+                                    __extbuf + sizeof(__extbuf),
+                                    __extbe);
+        size_t __nmemb = static_cast<size_t>(__extbe - __extbuf);
+        if (fwrite(__extbuf, 1, __nmemb, __file_) != __nmemb)
+            return -1;
+    } while (__r == codecvt_base::partial);
+    if (__r == codecvt_base::error)
+        return -1;
+    if (fflush(__file_))
+        return -1;
+    return 0;
+}
+
+template <class _CharT>
+void
+__stdoutbuf<_CharT>::imbue(const locale& __loc)
+{
+    sync();
+    __cv_ = &use_facet<codecvt<char_type, char, state_type> >(__loc);
+    __always_noconv_ = __cv_->always_noconv();
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP___STD_STREAM

diff --git a/libcxx/include/__tree b/libcxx/include/__tree
new file mode 100644
index 0000000..8030eef
--- /dev/null
+++ b/libcxx/include/__tree

@@ -0,0 +1,2305 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___TREE
+#define _LIBCPP___TREE
+
+#include <__config>
+#include <iterator>
+#include <memory>
+#include <stdexcept>
+#include <algorithm>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp, class _Compare, class _Allocator> class __tree;
+template <class _Tp, class _NodePtr, class _DiffType>
+    class _LIBCPP_TYPE_VIS_ONLY __tree_iterator;
+template <class _Tp, class _ConstNodePtr, class _DiffType>
+    class _LIBCPP_TYPE_VIS_ONLY __tree_const_iterator;
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+    class _LIBCPP_TYPE_VIS_ONLY map;
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+    class _LIBCPP_TYPE_VIS_ONLY multimap;
+template <class _Key, class _Compare, class _Allocator>
+    class _LIBCPP_TYPE_VIS_ONLY set;
+template <class _Key, class _Compare, class _Allocator>
+    class _LIBCPP_TYPE_VIS_ONLY multiset;
+
+/*
+
+_NodePtr algorithms
+
+The algorithms taking _NodePtr are red black tree algorithms.  Those
+algorithms taking a parameter named __root should assume that __root
+points to a proper red black tree (unless otherwise specified).
+
+Each algorithm herein assumes that __root->__parent_ points to a non-null
+structure which has a member __left_ which points back to __root.  No other
+member is read or written to at __root->__parent_.
+
+__root->__parent_ will be referred to below (in comments only) as end_node.
+end_node->__left_ is an externably accessible lvalue for __root, and can be
+changed by node insertion and removal (without explicit reference to end_node).
+
+All nodes (with the exception of end_node), even the node referred to as
+__root, have a non-null __parent_ field.
+
+*/
+
+// Returns:  true if __x is a left child of its parent, else false
+// Precondition:  __x != nullptr.
+template <class _NodePtr>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+__tree_is_left_child(_NodePtr __x) _NOEXCEPT
+{
+    return __x == __x->__parent_->__left_;
+}
+
+// Determintes if the subtree rooted at __x is a proper red black subtree.  If
+//    __x is a proper subtree, returns the black height (null counts as 1).  If
+//    __x is an improper subtree, returns 0.
+template <class _NodePtr>
+unsigned
+__tree_sub_invariant(_NodePtr __x)
+{
+    if (__x == nullptr)
+        return 1;
+    // parent consistency checked by caller
+    // check __x->__left_ consistency
+    if (__x->__left_ != nullptr && __x->__left_->__parent_ != __x)
+        return 0;
+    // check __x->__right_ consistency
+    if (__x->__right_ != nullptr && __x->__right_->__parent_ != __x)
+        return 0;
+    // check __x->__left_ != __x->__right_ unless both are nullptr
+    if (__x->__left_ == __x->__right_ && __x->__left_ != nullptr)
+        return 0;
+    // If this is red, neither child can be red
+    if (!__x->__is_black_)
+    {
+        if (__x->__left_ && !__x->__left_->__is_black_)
+            return 0;
+        if (__x->__right_ && !__x->__right_->__is_black_)
+            return 0;
+    }
+    unsigned __h = __tree_sub_invariant(__x->__left_);
+    if (__h == 0)
+        return 0;  // invalid left subtree
+    if (__h != __tree_sub_invariant(__x->__right_))
+        return 0;  // invalid or different height right subtree
+    return __h + __x->__is_black_;  // return black height of this node
+}
+
+// Determintes if the red black tree rooted at __root is a proper red black tree.
+//    __root == nullptr is a proper tree.  Returns true is __root is a proper
+//    red black tree, else returns false.
+template <class _NodePtr>
+bool
+__tree_invariant(_NodePtr __root)
+{
+    if (__root == nullptr)
+        return true;
+    // check __x->__parent_ consistency
+    if (__root->__parent_ == nullptr)
+        return false;
+    if (!__tree_is_left_child(__root))
+        return false;
+    // root must be black
+    if (!__root->__is_black_)
+        return false;
+    // do normal node checks
+    return __tree_sub_invariant(__root) != 0;
+}
+
+// Returns:  pointer to the left-most node under __x.
+// Precondition:  __x != nullptr.
+template <class _NodePtr>
+inline _LIBCPP_INLINE_VISIBILITY
+_NodePtr
+__tree_min(_NodePtr __x) _NOEXCEPT
+{
+    while (__x->__left_ != nullptr)
+        __x = __x->__left_;
+    return __x;
+}
+
+// Returns:  pointer to the right-most node under __x.
+// Precondition:  __x != nullptr.
+template <class _NodePtr>
+inline _LIBCPP_INLINE_VISIBILITY
+_NodePtr
+__tree_max(_NodePtr __x) _NOEXCEPT
+{
+    while (__x->__right_ != nullptr)
+        __x = __x->__right_;
+    return __x;
+}
+
+// Returns:  pointer to the next in-order node after __x.
+// Precondition:  __x != nullptr.
+template <class _NodePtr>
+_NodePtr
+__tree_next(_NodePtr __x) _NOEXCEPT
+{
+    if (__x->__right_ != nullptr)
+        return __tree_min(__x->__right_);
+    while (!__tree_is_left_child(__x))
+        __x = __x->__parent_;
+    return __x->__parent_;
+}
+
+// Returns:  pointer to the previous in-order node before __x.
+// Precondition:  __x != nullptr.
+template <class _NodePtr>
+_NodePtr
+__tree_prev(_NodePtr __x) _NOEXCEPT
+{
+    if (__x->__left_ != nullptr)
+        return __tree_max(__x->__left_);
+    while (__tree_is_left_child(__x))
+        __x = __x->__parent_;
+    return __x->__parent_;
+}
+
+// Returns:  pointer to a node which has no children
+// Precondition:  __x != nullptr.
+template <class _NodePtr>
+_NodePtr
+__tree_leaf(_NodePtr __x) _NOEXCEPT
+{
+    while (true)
+    {
+        if (__x->__left_ != nullptr)
+        {
+            __x = __x->__left_;
+            continue;
+        }
+        if (__x->__right_ != nullptr)
+        {
+            __x = __x->__right_;
+            continue;
+        }
+        break;
+    }
+    return __x;
+}
+
+// Effects:  Makes __x->__right_ the subtree root with __x as its left child
+//           while preserving in-order order.
+// Precondition:  __x->__right_ != nullptr
+template <class _NodePtr>
+void
+__tree_left_rotate(_NodePtr __x) _NOEXCEPT
+{
+    _NodePtr __y = __x->__right_;
+    __x->__right_ = __y->__left_;
+    if (__x->__right_ != nullptr)
+        __x->__right_->__parent_ = __x;
+    __y->__parent_ = __x->__parent_;
+    if (__tree_is_left_child(__x))
+        __x->__parent_->__left_ = __y;
+    else
+        __x->__parent_->__right_ = __y;
+    __y->__left_ = __x;
+    __x->__parent_ = __y;
+}
+
+// Effects:  Makes __x->__left_ the subtree root with __x as its right child
+//           while preserving in-order order.
+// Precondition:  __x->__left_ != nullptr
+template <class _NodePtr>
+void
+__tree_right_rotate(_NodePtr __x) _NOEXCEPT
+{
+    _NodePtr __y = __x->__left_;
+    __x->__left_ = __y->__right_;
+    if (__x->__left_ != nullptr)
+        __x->__left_->__parent_ = __x;
+    __y->__parent_ = __x->__parent_;
+    if (__tree_is_left_child(__x))
+        __x->__parent_->__left_ = __y;
+    else
+        __x->__parent_->__right_ = __y;
+    __y->__right_ = __x;
+    __x->__parent_ = __y;
+}
+
+// Effects:  Rebalances __root after attaching __x to a leaf.
+// Precondition:  __root != nulptr && __x != nullptr.
+//                __x has no children.
+//                __x == __root or == a direct or indirect child of __root.
+//                If __x were to be unlinked from __root (setting __root to
+//                  nullptr if __root == __x), __tree_invariant(__root) == true.
+// Postcondition: __tree_invariant(end_node->__left_) == true.  end_node->__left_
+//                may be different than the value passed in as __root.
+template <class _NodePtr>
+void
+__tree_balance_after_insert(_NodePtr __root, _NodePtr __x) _NOEXCEPT
+{
+    __x->__is_black_ = __x == __root;
+    while (__x != __root && !__x->__parent_->__is_black_)
+    {
+        // __x->__parent_ != __root because __x->__parent_->__is_black == false
+        if (__tree_is_left_child(__x->__parent_))
+        {
+            _NodePtr __y = __x->__parent_->__parent_->__right_;
+            if (__y != nullptr && !__y->__is_black_)
+            {
+                __x = __x->__parent_;
+                __x->__is_black_ = true;
+                __x = __x->__parent_;
+                __x->__is_black_ = __x == __root;
+                __y->__is_black_ = true;
+            }
+            else
+            {
+                if (!__tree_is_left_child(__x))
+                {
+                    __x = __x->__parent_;
+                    __tree_left_rotate(__x);
+                }
+                __x = __x->__parent_;
+                __x->__is_black_ = true;
+                __x = __x->__parent_;
+                __x->__is_black_ = false;
+                __tree_right_rotate(__x);
+                break;
+            }
+        }
+        else
+        {
+            _NodePtr __y = __x->__parent_->__parent_->__left_;
+            if (__y != nullptr && !__y->__is_black_)
+            {
+                __x = __x->__parent_;
+                __x->__is_black_ = true;
+                __x = __x->__parent_;
+                __x->__is_black_ = __x == __root;
+                __y->__is_black_ = true;
+            }
+            else
+            {
+                if (__tree_is_left_child(__x))
+                {
+                    __x = __x->__parent_;
+                    __tree_right_rotate(__x);
+                }
+                __x = __x->__parent_;
+                __x->__is_black_ = true;
+                __x = __x->__parent_;
+                __x->__is_black_ = false;
+                __tree_left_rotate(__x);
+                break;
+            }
+        }
+    }
+}
+
+// Precondition:  __root != nullptr && __z != nullptr.
+//                __tree_invariant(__root) == true.
+//                __z == __root or == a direct or indirect child of __root.
+// Effects:  unlinks __z from the tree rooted at __root, rebalancing as needed.
+// Postcondition: __tree_invariant(end_node->__left_) == true && end_node->__left_
+//                nor any of its children refer to __z.  end_node->__left_
+//                may be different than the value passed in as __root.
+template <class _NodePtr>
+void
+__tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT
+{
+    // __z will be removed from the tree.  Client still needs to destruct/deallocate it
+    // __y is either __z, or if __z has two children, __tree_next(__z).
+    // __y will have at most one child.
+    // __y will be the initial hole in the tree (make the hole at a leaf)
+    _NodePtr __y = (__z->__left_ == nullptr || __z->__right_ == nullptr) ?
+                    __z : __tree_next(__z);
+    // __x is __y's possibly null single child
+    _NodePtr __x = __y->__left_ != nullptr ? __y->__left_ : __y->__right_;
+    // __w is __x's possibly null uncle (will become __x's sibling)
+    _NodePtr __w = nullptr;
+    // link __x to __y's parent, and find __w
+    if (__x != nullptr)
+        __x->__parent_ = __y->__parent_;
+    if (__tree_is_left_child(__y))
+    {
+        __y->__parent_->__left_ = __x;
+        if (__y != __root)
+            __w = __y->__parent_->__right_;
+        else
+            __root = __x;  // __w == nullptr
+    }
+    else
+    {
+        __y->__parent_->__right_ = __x;
+        // __y can't be root if it is a right child
+        __w = __y->__parent_->__left_;
+    }
+    bool __removed_black = __y->__is_black_;
+    // If we didn't remove __z, do so now by splicing in __y for __z,
+    //    but copy __z's color.  This does not impact __x or __w.
+    if (__y != __z)
+    {
+        // __z->__left_ != nulptr but __z->__right_ might == __x == nullptr
+        __y->__parent_ = __z->__parent_;
+        if (__tree_is_left_child(__z))
+            __y->__parent_->__left_ = __y;
+        else
+            __y->__parent_->__right_ = __y;
+        __y->__left_ = __z->__left_;
+        __y->__left_->__parent_ = __y;
+        __y->__right_ = __z->__right_;
+        if (__y->__right_ != nullptr)
+            __y->__right_->__parent_ = __y;
+        __y->__is_black_ = __z->__is_black_;
+        if (__root == __z)
+            __root = __y;
+    }
+    // There is no need to rebalance if we removed a red, or if we removed
+    //     the last node.
+    if (__removed_black && __root != nullptr)
+    {
+        // Rebalance:
+        // __x has an implicit black color (transferred from the removed __y)
+        //    associated with it, no matter what its color is.
+        // If __x is __root (in which case it can't be null), it is supposed
+        //    to be black anyway, and if it is doubly black, then the double
+        //    can just be ignored.
+        // If __x is red (in which case it can't be null), then it can absorb
+        //    the implicit black just by setting its color to black.
+        // Since __y was black and only had one child (which __x points to), __x
+        //   is either red with no children, else null, otherwise __y would have
+        //   different black heights under left and right pointers.
+        // if (__x == __root || __x != nullptr && !__x->__is_black_)
+        if (__x != nullptr)
+            __x->__is_black_ = true;
+        else
+        {
+            //  Else __x isn't root, and is "doubly black", even though it may
+            //     be null.  __w can not be null here, else the parent would
+            //     see a black height >= 2 on the __x side and a black height
+            //     of 1 on the __w side (__w must be a non-null black or a red
+            //     with a non-null black child).
+            while (true)
+            {
+                if (!__tree_is_left_child(__w))  // if x is left child
+                {
+                    if (!__w->__is_black_)
+                    {
+                        __w->__is_black_ = true;
+                        __w->__parent_->__is_black_ = false;
+                        __tree_left_rotate(__w->__parent_);
+                        // __x is still valid
+                        // reset __root only if necessary
+                        if (__root == __w->__left_)
+                            __root = __w;
+                        // reset sibling, and it still can't be null
+                        __w = __w->__left_->__right_;
+                    }
+                    // __w->__is_black_ is now true, __w may have null children
+                    if ((__w->__left_  == nullptr || __w->__left_->__is_black_) &&
+                        (__w->__right_ == nullptr || __w->__right_->__is_black_))
+                    {
+                        __w->__is_black_ = false;
+                        __x = __w->__parent_;
+                        // __x can no longer be null
+                        if (__x == __root || !__x->__is_black_)
+                        {
+                            __x->__is_black_ = true;
+                            break;
+                        }
+                        // reset sibling, and it still can't be null
+                        __w = __tree_is_left_child(__x) ?
+                                    __x->__parent_->__right_ :
+                                    __x->__parent_->__left_;
+                        // continue;
+                    }
+                    else  // __w has a red child
+                    {
+                        if (__w->__right_ == nullptr || __w->__right_->__is_black_)
+                        {
+                            // __w left child is non-null and red
+                            __w->__left_->__is_black_ = true;
+                            __w->__is_black_ = false;
+                            __tree_right_rotate(__w);
+                            // __w is known not to be root, so root hasn't changed
+                            // reset sibling, and it still can't be null
+                            __w = __w->__parent_;
+                        }
+                        // __w has a right red child, left child may be null
+                        __w->__is_black_ = __w->__parent_->__is_black_;
+                        __w->__parent_->__is_black_ = true;
+                        __w->__right_->__is_black_ = true;
+                        __tree_left_rotate(__w->__parent_);
+                        break;
+                    }
+                }
+                else
+                {
+                    if (!__w->__is_black_)
+                    {
+                        __w->__is_black_ = true;
+                        __w->__parent_->__is_black_ = false;
+                        __tree_right_rotate(__w->__parent_);
+                        // __x is still valid
+                        // reset __root only if necessary
+                        if (__root == __w->__right_)
+                            __root = __w;
+                        // reset sibling, and it still can't be null
+                        __w = __w->__right_->__left_;
+                    }
+                    // __w->__is_black_ is now true, __w may have null children
+                    if ((__w->__left_  == nullptr || __w->__left_->__is_black_) &&
+                        (__w->__right_ == nullptr || __w->__right_->__is_black_))
+                    {
+                        __w->__is_black_ = false;
+                        __x = __w->__parent_;
+                        // __x can no longer be null
+                        if (!__x->__is_black_ || __x == __root)
+                        {
+                            __x->__is_black_ = true;
+                            break;
+                        }
+                        // reset sibling, and it still can't be null
+                        __w = __tree_is_left_child(__x) ?
+                                    __x->__parent_->__right_ :
+                                    __x->__parent_->__left_;
+                        // continue;
+                    }
+                    else  // __w has a red child
+                    {
+                        if (__w->__left_ == nullptr || __w->__left_->__is_black_)
+                        {
+                            // __w right child is non-null and red
+                            __w->__right_->__is_black_ = true;
+                            __w->__is_black_ = false;
+                            __tree_left_rotate(__w);
+                            // __w is known not to be root, so root hasn't changed
+                            // reset sibling, and it still can't be null
+                            __w = __w->__parent_;
+                        }
+                        // __w has a left red child, right child may be null
+                        __w->__is_black_ = __w->__parent_->__is_black_;
+                        __w->__parent_->__is_black_ = true;
+                        __w->__left_->__is_black_ = true;
+                        __tree_right_rotate(__w->__parent_);
+                        break;
+                    }
+                }
+            }
+        }
+    }
+}
+
+template <class _Allocator> class __map_node_destructor;
+
+template <class _Allocator>
+class __tree_node_destructor
+{
+    typedef _Allocator                                      allocator_type;
+    typedef allocator_traits<allocator_type>                __alloc_traits;
+    typedef typename __alloc_traits::value_type::value_type value_type;
+public:
+    typedef typename __alloc_traits::pointer                pointer;
+private:
+
+    allocator_type& __na_;
+
+    __tree_node_destructor& operator=(const __tree_node_destructor&);
+
+public:
+    bool __value_constructed;
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __tree_node_destructor(allocator_type& __na, bool __val = false) _NOEXCEPT
+        : __na_(__na),
+          __value_constructed(__val)
+        {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void operator()(pointer __p) _NOEXCEPT
+    {
+        if (__value_constructed)
+            __alloc_traits::destroy(__na_, _VSTD::addressof(__p->__value_));
+        if (__p)
+            __alloc_traits::deallocate(__na_, __p, 1);
+    }
+
+    template <class> friend class __map_node_destructor;
+};
+
+// node
+
+template <class _Pointer>
+class __tree_end_node
+{
+public:
+    typedef _Pointer pointer;
+    pointer __left_;
+
+    _LIBCPP_INLINE_VISIBILITY
+    __tree_end_node() _NOEXCEPT : __left_() {}
+};
+
+template <class _VoidPtr>
+class __tree_node_base
+    : public __tree_end_node
+             <
+                typename pointer_traits<_VoidPtr>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+                     rebind<__tree_node_base<_VoidPtr> >
+#else
+                     rebind<__tree_node_base<_VoidPtr> >::other
+#endif
+             >
+{
+    __tree_node_base(const __tree_node_base&);
+    __tree_node_base& operator=(const __tree_node_base&);
+public:
+    typedef typename pointer_traits<_VoidPtr>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<__tree_node_base>
+#else
+            rebind<__tree_node_base>::other
+#endif
+                                                pointer;
+    typedef typename pointer_traits<_VoidPtr>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<const __tree_node_base>
+#else
+            rebind<const __tree_node_base>::other
+#endif
+                                                const_pointer;
+    typedef __tree_end_node<pointer> base;
+
+    pointer __right_;
+    pointer __parent_;
+    bool __is_black_;
+
+    _LIBCPP_INLINE_VISIBILITY
+    __tree_node_base() _NOEXCEPT
+        : __right_(), __parent_(), __is_black_(false) {}
+};
+
+template <class _Tp, class _VoidPtr>
+class __tree_node
+    : public __tree_node_base<_VoidPtr>
+{
+public:
+    typedef __tree_node_base<_VoidPtr> base;
+    typedef _Tp value_type;
+
+    value_type __value_;
+
+#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+    template <class ..._Args>
+        _LIBCPP_INLINE_VISIBILITY
+        explicit __tree_node(_Args&& ...__args)
+            : __value_(_VSTD::forward<_Args>(__args)...) {}
+#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __tree_node(const value_type& __v)
+            : __value_(__v) {}
+#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+};
+
+template <class _TreeIterator> class _LIBCPP_TYPE_VIS_ONLY __map_iterator;
+template <class _TreeIterator> class _LIBCPP_TYPE_VIS_ONLY __map_const_iterator;
+
+template <class _Tp, class _NodePtr, class _DiffType>
+class _LIBCPP_TYPE_VIS_ONLY __tree_iterator
+{
+    typedef _NodePtr                                              __node_pointer;
+    typedef typename pointer_traits<__node_pointer>::element_type __node;
+
+    __node_pointer __ptr_;
+
+    typedef pointer_traits<__node_pointer> __pointer_traits;
+public:
+    typedef bidirectional_iterator_tag iterator_category;
+    typedef _Tp                        value_type;
+    typedef _DiffType                  difference_type;
+    typedef value_type&                reference;
+    typedef typename pointer_traits<__node_pointer>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<value_type>
+#else
+            rebind<value_type>::other
+#endif
+                                       pointer;
+
+    _LIBCPP_INLINE_VISIBILITY __tree_iterator() _NOEXCEPT
+#if _LIBCPP_STD_VER > 11
+    : __ptr_(nullptr)
+#endif
+    {}
+
+    _LIBCPP_INLINE_VISIBILITY reference operator*() const {return __ptr_->__value_;}
+    _LIBCPP_INLINE_VISIBILITY pointer operator->() const
+        {return pointer_traits<pointer>::pointer_to(__ptr_->__value_);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __tree_iterator& operator++() {
+      __ptr_ = static_cast<__node_pointer>(
+          __tree_next(static_cast<typename __node::base::pointer>(__ptr_)));
+      return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    __tree_iterator operator++(int)
+        {__tree_iterator __t(*this); ++(*this); return __t;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __tree_iterator& operator--() {
+      __ptr_ = static_cast<__node_pointer>(
+          __tree_prev(static_cast<typename __node::base::pointer>(__ptr_)));
+      return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    __tree_iterator operator--(int)
+        {__tree_iterator __t(*this); --(*this); return __t;}
+
+    friend _LIBCPP_INLINE_VISIBILITY 
+        bool operator==(const __tree_iterator& __x, const __tree_iterator& __y)
+        {return __x.__ptr_ == __y.__ptr_;}
+    friend _LIBCPP_INLINE_VISIBILITY
+        bool operator!=(const __tree_iterator& __x, const __tree_iterator& __y)
+        {return !(__x == __y);}
+
+private:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __tree_iterator(__node_pointer __p) _NOEXCEPT : __ptr_(__p) {}
+    template <class, class, class> friend class __tree;
+    template <class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY __tree_const_iterator;
+    template <class> friend class _LIBCPP_TYPE_VIS_ONLY __map_iterator;
+    template <class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY map;
+    template <class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY multimap;
+    template <class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY set;
+    template <class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY multiset;
+};
+
+template <class _Tp, class _ConstNodePtr, class _DiffType>
+class _LIBCPP_TYPE_VIS_ONLY __tree_const_iterator
+{
+    typedef _ConstNodePtr                                         __node_pointer;
+    typedef typename pointer_traits<__node_pointer>::element_type __node;
+
+    __node_pointer __ptr_;
+
+    typedef pointer_traits<__node_pointer> __pointer_traits;
+public:
+    typedef bidirectional_iterator_tag       iterator_category;
+    typedef _Tp                              value_type;
+    typedef _DiffType                        difference_type;
+    typedef const value_type&                reference;
+    typedef typename pointer_traits<__node_pointer>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<const value_type>
+#else
+            rebind<const value_type>::other
+#endif
+                                       pointer;
+
+    _LIBCPP_INLINE_VISIBILITY __tree_const_iterator() _NOEXCEPT
+#if _LIBCPP_STD_VER > 11
+    : __ptr_(nullptr)
+#endif
+    {}
+
+private:
+    typedef typename remove_const<__node>::type  __non_const_node;
+    typedef typename pointer_traits<__node_pointer>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<__non_const_node>
+#else
+            rebind<__non_const_node>::other
+#endif
+                                                 __non_const_node_pointer;
+    typedef __tree_iterator<value_type, __non_const_node_pointer, difference_type>
+                                                 __non_const_iterator;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    __tree_const_iterator(__non_const_iterator __p) _NOEXCEPT
+        : __ptr_(__p.__ptr_) {}
+
+    _LIBCPP_INLINE_VISIBILITY reference operator*() const {return __ptr_->__value_;}
+    _LIBCPP_INLINE_VISIBILITY pointer operator->() const
+        {return pointer_traits<pointer>::pointer_to(__ptr_->__value_);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __tree_const_iterator& operator++() {
+      typedef typename pointer_traits<__node_pointer>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+          rebind<typename __node::base>
+#else
+          rebind<typename __node::base>::other
+#endif
+              __node_base_pointer;
+
+      __ptr_ = static_cast<__node_pointer>(
+          __tree_next(static_cast<__node_base_pointer>(__ptr_)));
+      return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __tree_const_iterator operator++(int)
+        {__tree_const_iterator __t(*this); ++(*this); return __t;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __tree_const_iterator& operator--() {
+      typedef typename pointer_traits<__node_pointer>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+          rebind<typename __node::base>
+#else
+          rebind<typename __node::base>::other
+#endif
+              __node_base_pointer;
+
+      __ptr_ = static_cast<__node_pointer>(
+          __tree_prev(static_cast<__node_base_pointer>(__ptr_)));
+      return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __tree_const_iterator operator--(int)
+        {__tree_const_iterator __t(*this); --(*this); return __t;}
+
+    friend _LIBCPP_INLINE_VISIBILITY
+        bool operator==(const __tree_const_iterator& __x, const __tree_const_iterator& __y)
+        {return __x.__ptr_ == __y.__ptr_;}
+    friend _LIBCPP_INLINE_VISIBILITY
+        bool operator!=(const __tree_const_iterator& __x, const __tree_const_iterator& __y)
+        {return !(__x == __y);}
+
+private:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __tree_const_iterator(__node_pointer __p) _NOEXCEPT
+        : __ptr_(__p) {}
+    template <class, class, class> friend class __tree;
+    template <class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY map;
+    template <class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY multimap;
+    template <class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY set;
+    template <class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY multiset;
+    template <class> friend class _LIBCPP_TYPE_VIS_ONLY __map_const_iterator;
+};
+
+template <class _Tp, class _Compare, class _Allocator>
+class __tree
+{
+public:
+    typedef _Tp                                      value_type;
+    typedef _Compare                                 value_compare;
+    typedef _Allocator                               allocator_type;
+    typedef allocator_traits<allocator_type>         __alloc_traits;
+    typedef typename __alloc_traits::pointer         pointer;
+    typedef typename __alloc_traits::const_pointer   const_pointer;
+    typedef typename __alloc_traits::size_type       size_type;
+    typedef typename __alloc_traits::difference_type difference_type;
+
+    typedef typename __alloc_traits::void_pointer  __void_pointer;
+
+    typedef __tree_node<value_type, __void_pointer> __node;
+    typedef __tree_node_base<__void_pointer>        __node_base;
+    typedef typename __rebind_alloc_helper<__alloc_traits, __node>::type __node_allocator;
+    typedef allocator_traits<__node_allocator>       __node_traits;
+    typedef typename __node_traits::pointer          __node_pointer;
+    typedef typename __node_traits::pointer          __node_const_pointer;
+    typedef typename __node_base::pointer            __node_base_pointer;
+    typedef typename __node_base::pointer            __node_base_const_pointer;
+private:
+    typedef typename __node_base::base __end_node_t;
+    typedef typename pointer_traits<__node_pointer>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<__end_node_t>
+#else
+            rebind<__end_node_t>::other
+#endif
+                                                     __end_node_ptr;
+    typedef typename pointer_traits<__node_pointer>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<__end_node_t>
+#else
+            rebind<__end_node_t>::other
+#endif
+                                                     __end_node_const_ptr;
+
+    __node_pointer                                          __begin_node_;
+    __compressed_pair<__end_node_t, __node_allocator>  __pair1_;
+    __compressed_pair<size_type, value_compare>        __pair3_;
+
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    __node_pointer __end_node() _NOEXCEPT
+    {
+        return static_cast<__node_pointer>
+               (
+                   pointer_traits<__end_node_ptr>::pointer_to(__pair1_.first())
+               );
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    __node_const_pointer __end_node() const _NOEXCEPT
+    {
+        return static_cast<__node_const_pointer>
+               (
+                   pointer_traits<__end_node_const_ptr>::pointer_to(const_cast<__end_node_t&>(__pair1_.first()))
+               );
+    }
+    _LIBCPP_INLINE_VISIBILITY
+          __node_allocator& __node_alloc() _NOEXCEPT {return __pair1_.second();}
+private:
+    _LIBCPP_INLINE_VISIBILITY
+    const __node_allocator& __node_alloc() const _NOEXCEPT
+        {return __pair1_.second();}
+    _LIBCPP_INLINE_VISIBILITY
+          __node_pointer& __begin_node() _NOEXCEPT {return __begin_node_;}
+    _LIBCPP_INLINE_VISIBILITY
+    const __node_pointer& __begin_node() const _NOEXCEPT {return __begin_node_;}
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    allocator_type __alloc() const _NOEXCEPT
+        {return allocator_type(__node_alloc());}
+private:
+    _LIBCPP_INLINE_VISIBILITY
+          size_type& size() _NOEXCEPT {return __pair3_.first();}
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    const size_type& size() const _NOEXCEPT {return __pair3_.first();}
+    _LIBCPP_INLINE_VISIBILITY
+          value_compare& value_comp() _NOEXCEPT {return __pair3_.second();}
+    _LIBCPP_INLINE_VISIBILITY
+    const value_compare& value_comp() const _NOEXCEPT
+        {return __pair3_.second();}
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    __node_pointer __root() _NOEXCEPT
+        {return static_cast<__node_pointer>      (__end_node()->__left_);}
+    _LIBCPP_INLINE_VISIBILITY
+    __node_const_pointer __root() const _NOEXCEPT
+        {return static_cast<__node_const_pointer>(__end_node()->__left_);}
+
+    typedef __tree_iterator<value_type, __node_pointer, difference_type>             iterator;
+    typedef __tree_const_iterator<value_type, __node_pointer, difference_type> const_iterator;
+
+    explicit __tree(const value_compare& __comp)
+        _NOEXCEPT_(
+            is_nothrow_default_constructible<__node_allocator>::value &&
+            is_nothrow_copy_constructible<value_compare>::value);
+    explicit __tree(const allocator_type& __a);
+    __tree(const value_compare& __comp, const allocator_type& __a);
+    __tree(const __tree& __t);
+    __tree& operator=(const __tree& __t);
+    template <class _InputIterator>
+        void __assign_unique(_InputIterator __first, _InputIterator __last);
+    template <class _InputIterator>
+        void __assign_multi(_InputIterator __first, _InputIterator __last);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    __tree(__tree&& __t)
+        _NOEXCEPT_(
+            is_nothrow_move_constructible<__node_allocator>::value &&
+            is_nothrow_move_constructible<value_compare>::value);
+    __tree(__tree&& __t, const allocator_type& __a);
+    __tree& operator=(__tree&& __t)
+        _NOEXCEPT_(
+            __node_traits::propagate_on_container_move_assignment::value &&
+            is_nothrow_move_assignable<value_compare>::value &&
+            is_nothrow_move_assignable<__node_allocator>::value);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    ~__tree();
+
+    _LIBCPP_INLINE_VISIBILITY
+          iterator begin()  _NOEXCEPT {return       iterator(__begin_node());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator begin() const _NOEXCEPT {return const_iterator(__begin_node());}
+    _LIBCPP_INLINE_VISIBILITY
+          iterator end() _NOEXCEPT {return       iterator(__end_node());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator end() const _NOEXCEPT {return const_iterator(__end_node());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type max_size() const _NOEXCEPT
+        {return __node_traits::max_size(__node_alloc());}
+
+    void clear() _NOEXCEPT;
+
+    void swap(__tree& __t)
+        _NOEXCEPT_(
+            __is_nothrow_swappable<value_compare>::value
+#if _LIBCPP_STD_VER <= 11
+            && (!__node_traits::propagate_on_container_swap::value ||
+                 __is_nothrow_swappable<__node_allocator>::value)
+#endif
+            );
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    template <class... _Args>
+        pair<iterator, bool>
+        __emplace_unique(_Args&&... __args);
+    template <class... _Args>
+        iterator
+        __emplace_multi(_Args&&... __args);
+
+    template <class... _Args>
+        iterator
+        __emplace_hint_unique(const_iterator __p, _Args&&... __args);
+    template <class... _Args>
+        iterator
+        __emplace_hint_multi(const_iterator __p, _Args&&... __args);
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+    template <class _Vp>
+        pair<iterator, bool> __insert_unique(_Vp&& __v);
+    template <class _Vp>
+        iterator __insert_unique(const_iterator __p, _Vp&& __v);
+    template <class _Vp>
+        iterator __insert_multi(_Vp&& __v);
+    template <class _Vp>
+        iterator __insert_multi(const_iterator __p, _Vp&& __v);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    pair<iterator, bool> __insert_unique(const value_type& __v);
+    iterator __insert_unique(const_iterator __p, const value_type& __v);
+    iterator __insert_multi(const value_type& __v);
+    iterator __insert_multi(const_iterator __p, const value_type& __v);
+
+    pair<iterator, bool> __node_insert_unique(__node_pointer __nd);
+    iterator             __node_insert_unique(const_iterator __p,
+                                              __node_pointer __nd);
+
+    iterator __node_insert_multi(__node_pointer __nd);
+    iterator __node_insert_multi(const_iterator __p, __node_pointer __nd);
+
+    iterator erase(const_iterator __p);
+    iterator erase(const_iterator __f, const_iterator __l);
+    template <class _Key>
+        size_type __erase_unique(const _Key& __k);
+    template <class _Key>
+        size_type __erase_multi(const _Key& __k);
+
+    void __insert_node_at(__node_base_pointer __parent,
+                          __node_base_pointer& __child,
+                          __node_base_pointer __new_node);
+
+    template <class _Key>
+        iterator find(const _Key& __v);
+    template <class _Key>
+        const_iterator find(const _Key& __v) const;
+
+    template <class _Key>
+        size_type __count_unique(const _Key& __k) const;
+    template <class _Key>
+        size_type __count_multi(const _Key& __k) const;
+
+    template <class _Key>
+        _LIBCPP_INLINE_VISIBILITY
+        iterator lower_bound(const _Key& __v)
+            {return __lower_bound(__v, __root(), __end_node());}
+    template <class _Key>
+        iterator __lower_bound(const _Key& __v,
+                               __node_pointer __root,
+                               __node_pointer __result);
+    template <class _Key>
+        _LIBCPP_INLINE_VISIBILITY
+        const_iterator lower_bound(const _Key& __v) const
+            {return __lower_bound(__v, __root(), __end_node());}
+    template <class _Key>
+        const_iterator __lower_bound(const _Key& __v,
+                                     __node_const_pointer __root,
+                                     __node_const_pointer __result) const;
+    template <class _Key>
+        _LIBCPP_INLINE_VISIBILITY
+        iterator upper_bound(const _Key& __v)
+            {return __upper_bound(__v, __root(), __end_node());}
+    template <class _Key>
+        iterator __upper_bound(const _Key& __v,
+                               __node_pointer __root,
+                               __node_pointer __result);
+    template <class _Key>
+        _LIBCPP_INLINE_VISIBILITY
+        const_iterator upper_bound(const _Key& __v) const
+            {return __upper_bound(__v, __root(), __end_node());}
+    template <class _Key>
+        const_iterator __upper_bound(const _Key& __v,
+                                     __node_const_pointer __root,
+                                     __node_const_pointer __result) const;
+    template <class _Key>
+        pair<iterator, iterator>
+        __equal_range_unique(const _Key& __k);
+    template <class _Key>
+        pair<const_iterator, const_iterator>
+        __equal_range_unique(const _Key& __k) const;
+
+    template <class _Key>
+        pair<iterator, iterator>
+        __equal_range_multi(const _Key& __k);
+    template <class _Key>
+        pair<const_iterator, const_iterator>
+        __equal_range_multi(const _Key& __k) const;
+
+    typedef __tree_node_destructor<__node_allocator> _Dp;
+    typedef unique_ptr<__node, _Dp> __node_holder;
+
+    __node_holder remove(const_iterator __p) _NOEXCEPT;
+private:
+    typename __node_base::pointer&
+        __find_leaf_low(typename __node_base::pointer& __parent, const value_type& __v);
+    typename __node_base::pointer&
+        __find_leaf_high(typename __node_base::pointer& __parent, const value_type& __v);
+    typename __node_base::pointer&
+        __find_leaf(const_iterator __hint,
+                    typename __node_base::pointer& __parent, const value_type& __v);
+    template <class _Key>
+        typename __node_base::pointer&
+        __find_equal(typename __node_base::pointer& __parent, const _Key& __v);
+    template <class _Key>
+        typename __node_base::pointer&
+        __find_equal(const_iterator __hint, typename __node_base::pointer& __parent,
+                     const _Key& __v);
+
+#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+    template <class ..._Args>
+        __node_holder __construct_node(_Args&& ...__args);
+#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+        __node_holder __construct_node(const value_type& __v);
+#endif
+
+    void destroy(__node_pointer __nd) _NOEXCEPT;
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __copy_assign_alloc(const __tree& __t)
+        {__copy_assign_alloc(__t, integral_constant<bool,
+             __node_traits::propagate_on_container_copy_assignment::value>());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __copy_assign_alloc(const __tree& __t, true_type)
+        {__node_alloc() = __t.__node_alloc();}
+    _LIBCPP_INLINE_VISIBILITY
+    void __copy_assign_alloc(const __tree& __t, false_type) {}
+
+    void __move_assign(__tree& __t, false_type);
+    void __move_assign(__tree& __t, true_type)
+        _NOEXCEPT_(is_nothrow_move_assignable<value_compare>::value &&
+                   is_nothrow_move_assignable<__node_allocator>::value);
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__tree& __t)
+        _NOEXCEPT_(
+            !__node_traits::propagate_on_container_move_assignment::value ||
+            is_nothrow_move_assignable<__node_allocator>::value)
+        {__move_assign_alloc(__t, integral_constant<bool,
+             __node_traits::propagate_on_container_move_assignment::value>());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__tree& __t, true_type)
+        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value)
+        {__node_alloc() = _VSTD::move(__t.__node_alloc());}
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__tree& __t, false_type) _NOEXCEPT {}
+
+    __node_pointer __detach();
+    static __node_pointer __detach(__node_pointer);
+
+    template <class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY map;
+    template <class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY multimap;
+};
+
+template <class _Tp, class _Compare, class _Allocator>
+__tree<_Tp, _Compare, _Allocator>::__tree(const value_compare& __comp)
+        _NOEXCEPT_(
+            is_nothrow_default_constructible<__node_allocator>::value &&
+            is_nothrow_copy_constructible<value_compare>::value)
+    : __pair3_(0, __comp)
+{
+    __begin_node() = __end_node();
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+__tree<_Tp, _Compare, _Allocator>::__tree(const allocator_type& __a)
+    : __begin_node_(__node_pointer()),
+      __pair1_(__node_allocator(__a)),
+      __pair3_(0)
+{
+    __begin_node() = __end_node();
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+__tree<_Tp, _Compare, _Allocator>::__tree(const value_compare& __comp,
+                                           const allocator_type& __a)
+    : __begin_node_(__node_pointer()),
+      __pair1_(__node_allocator(__a)),
+      __pair3_(0, __comp)
+{
+    __begin_node() = __end_node();
+}
+
+// Precondition:  size() != 0
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::__node_pointer
+__tree<_Tp, _Compare, _Allocator>::__detach()
+{
+    __node_pointer __cache = __begin_node();
+    __begin_node() = __end_node();
+    __end_node()->__left_->__parent_ = nullptr;
+    __end_node()->__left_ = nullptr;
+    size() = 0;
+    // __cache->__left_ == nullptr
+    if (__cache->__right_ != nullptr)
+        __cache = static_cast<__node_pointer>(__cache->__right_);
+    // __cache->__left_ == nullptr
+    // __cache->__right_ == nullptr
+    return __cache;
+}
+
+// Precondition:  __cache != nullptr
+//    __cache->left_ == nullptr
+//    __cache->right_ == nullptr
+//    This is no longer a red-black tree
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::__node_pointer
+__tree<_Tp, _Compare, _Allocator>::__detach(__node_pointer __cache)
+{
+    if (__cache->__parent_ == nullptr)
+        return nullptr;
+    if (__tree_is_left_child(static_cast<__node_base_pointer>(__cache)))
+    {
+        __cache->__parent_->__left_ = nullptr;
+        __cache = static_cast<__node_pointer>(__cache->__parent_);
+        if (__cache->__right_ == nullptr)
+            return __cache;
+        return static_cast<__node_pointer>(__tree_leaf(__cache->__right_));
+    }
+    // __cache is right child
+    __cache->__parent_->__right_ = nullptr;
+    __cache = static_cast<__node_pointer>(__cache->__parent_);
+    if (__cache->__left_ == nullptr)
+        return __cache;
+    return static_cast<__node_pointer>(__tree_leaf(__cache->__left_));
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+__tree<_Tp, _Compare, _Allocator>&
+__tree<_Tp, _Compare, _Allocator>::operator=(const __tree& __t)
+{
+    if (this != &__t)
+    {
+        value_comp() = __t.value_comp();
+        __copy_assign_alloc(__t);
+        __assign_multi(__t.begin(), __t.end());
+    }
+    return *this;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _InputIterator>
+void
+__tree<_Tp, _Compare, _Allocator>::__assign_unique(_InputIterator __first, _InputIterator __last)
+{
+    if (size() != 0)
+    {
+        __node_pointer __cache = __detach();
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        try
+        {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            for (; __cache != nullptr && __first != __last; ++__first)
+            {
+                __cache->__value_ = *__first;
+                __node_pointer __next = __detach(__cache);
+                __node_insert_unique(__cache);
+                __cache = __next;
+            }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        }
+        catch (...)
+        {
+            while (__cache->__parent_ != nullptr)
+                __cache = static_cast<__node_pointer>(__cache->__parent_);
+            destroy(__cache);
+            throw;
+        }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        if (__cache != nullptr)
+        {
+            while (__cache->__parent_ != nullptr)
+                __cache = static_cast<__node_pointer>(__cache->__parent_);
+            destroy(__cache);
+        }
+    }
+    for (; __first != __last; ++__first)
+        __insert_unique(*__first);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _InputIterator>
+void
+__tree<_Tp, _Compare, _Allocator>::__assign_multi(_InputIterator __first, _InputIterator __last)
+{
+    if (size() != 0)
+    {
+        __node_pointer __cache = __detach();
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        try
+        {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            for (; __cache != nullptr && __first != __last; ++__first)
+            {
+                __cache->__value_ = *__first;
+                __node_pointer __next = __detach(__cache);
+                __node_insert_multi(__cache);
+                __cache = __next;
+            }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        }
+        catch (...)
+        {
+            while (__cache->__parent_ != nullptr)
+                __cache = static_cast<__node_pointer>(__cache->__parent_);
+            destroy(__cache);
+            throw;
+        }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        if (__cache != nullptr)
+        {
+            while (__cache->__parent_ != nullptr)
+                __cache = static_cast<__node_pointer>(__cache->__parent_);
+            destroy(__cache);
+        }
+    }
+    for (; __first != __last; ++__first)
+        __insert_multi(*__first);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+__tree<_Tp, _Compare, _Allocator>::__tree(const __tree& __t)
+    : __begin_node_(__node_pointer()),
+      __pair1_(__node_traits::select_on_container_copy_construction(__t.__node_alloc())),
+      __pair3_(0, __t.value_comp())
+{
+    __begin_node() = __end_node();
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Compare, class _Allocator>
+__tree<_Tp, _Compare, _Allocator>::__tree(__tree&& __t)
+    _NOEXCEPT_(
+        is_nothrow_move_constructible<__node_allocator>::value &&
+        is_nothrow_move_constructible<value_compare>::value)
+    : __begin_node_(_VSTD::move(__t.__begin_node_)),
+      __pair1_(_VSTD::move(__t.__pair1_)),
+      __pair3_(_VSTD::move(__t.__pair3_))
+{
+    if (size() == 0)
+        __begin_node() = __end_node();
+    else
+    {
+        __end_node()->__left_->__parent_ = static_cast<__node_base_pointer>(__end_node());
+        __t.__begin_node() = __t.__end_node();
+        __t.__end_node()->__left_ = nullptr;
+        __t.size() = 0;
+    }
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+__tree<_Tp, _Compare, _Allocator>::__tree(__tree&& __t, const allocator_type& __a)
+    : __pair1_(__node_allocator(__a)),
+      __pair3_(0, _VSTD::move(__t.value_comp()))
+{
+    if (__a == __t.__alloc())
+    {
+        if (__t.size() == 0)
+            __begin_node() = __end_node();
+        else
+        {
+            __begin_node() = __t.__begin_node();
+            __end_node()->__left_ = __t.__end_node()->__left_;
+            __end_node()->__left_->__parent_ = static_cast<__node_base_pointer>(__end_node());
+            size() = __t.size();
+            __t.__begin_node() = __t.__end_node();
+            __t.__end_node()->__left_ = nullptr;
+            __t.size() = 0;
+        }
+    }
+    else
+    {
+        __begin_node() = __end_node();
+    }
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+void
+__tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, true_type)
+    _NOEXCEPT_(is_nothrow_move_assignable<value_compare>::value &&
+               is_nothrow_move_assignable<__node_allocator>::value)
+{
+    destroy(static_cast<__node_pointer>(__end_node()->__left_));
+    __begin_node_ = __t.__begin_node_;
+    __pair1_.first() = __t.__pair1_.first();
+    __move_assign_alloc(__t);
+    __pair3_ = _VSTD::move(__t.__pair3_);
+    if (size() == 0)
+        __begin_node() = __end_node();
+    else
+    {
+        __end_node()->__left_->__parent_ = static_cast<__node_base_pointer>(__end_node());
+        __t.__begin_node() = __t.__end_node();
+        __t.__end_node()->__left_ = nullptr;
+        __t.size() = 0;
+    }
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+void
+__tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, false_type)
+{
+    if (__node_alloc() == __t.__node_alloc())
+        __move_assign(__t, true_type());
+    else
+    {
+        value_comp() = _VSTD::move(__t.value_comp());
+        const_iterator __e = end();
+        if (size() != 0)
+        {
+            __node_pointer __cache = __detach();
+#ifndef _LIBCPP_NO_EXCEPTIONS
+            try
+            {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+                while (__cache != nullptr && __t.size() != 0)
+                {
+                    __cache->__value_ = _VSTD::move(__t.remove(__t.begin())->__value_);
+                    __node_pointer __next = __detach(__cache);
+                    __node_insert_multi(__cache);
+                    __cache = __next;
+                }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+            }
+            catch (...)
+            {
+                while (__cache->__parent_ != nullptr)
+                    __cache = static_cast<__node_pointer>(__cache->__parent_);
+                destroy(__cache);
+                throw;
+            }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            if (__cache != nullptr)
+            {
+                while (__cache->__parent_ != nullptr)
+                    __cache = static_cast<__node_pointer>(__cache->__parent_);
+                destroy(__cache);
+            }
+        }
+        while (__t.size() != 0)
+            __insert_multi(__e, _VSTD::move(__t.remove(__t.begin())->__value_));
+    }
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+__tree<_Tp, _Compare, _Allocator>&
+__tree<_Tp, _Compare, _Allocator>::operator=(__tree&& __t)
+    _NOEXCEPT_(
+        __node_traits::propagate_on_container_move_assignment::value &&
+        is_nothrow_move_assignable<value_compare>::value &&
+        is_nothrow_move_assignable<__node_allocator>::value)
+        
+{
+    __move_assign(__t, integral_constant<bool,
+                  __node_traits::propagate_on_container_move_assignment::value>());
+    return *this;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Compare, class _Allocator>
+__tree<_Tp, _Compare, _Allocator>::~__tree()
+{
+    destroy(__root());
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+void
+__tree<_Tp, _Compare, _Allocator>::destroy(__node_pointer __nd) _NOEXCEPT
+{
+    if (__nd != nullptr)
+    {
+        destroy(static_cast<__node_pointer>(__nd->__left_));
+        destroy(static_cast<__node_pointer>(__nd->__right_));
+        __node_allocator& __na = __node_alloc();
+        __node_traits::destroy(__na, _VSTD::addressof(__nd->__value_));
+        __node_traits::deallocate(__na, __nd, 1);
+    }
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+void
+__tree<_Tp, _Compare, _Allocator>::swap(__tree& __t)
+        _NOEXCEPT_(
+            __is_nothrow_swappable<value_compare>::value
+#if _LIBCPP_STD_VER <= 11
+            && (!__node_traits::propagate_on_container_swap::value ||
+                 __is_nothrow_swappable<__node_allocator>::value)
+#endif
+            )
+{
+    using _VSTD::swap;
+    swap(__begin_node_, __t.__begin_node_);
+    swap(__pair1_.first(), __t.__pair1_.first());
+    __swap_allocator(__node_alloc(), __t.__node_alloc());
+    __pair3_.swap(__t.__pair3_);
+    if (size() == 0)
+        __begin_node() = __end_node();
+    else
+        __end_node()->__left_->__parent_ = static_cast<__node_base_pointer>(__end_node());
+    if (__t.size() == 0)
+        __t.__begin_node() = __t.__end_node();
+    else
+        __t.__end_node()->__left_->__parent_ = static_cast<__node_base_pointer>(__t.__end_node());
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+void
+__tree<_Tp, _Compare, _Allocator>::clear() _NOEXCEPT
+{
+    destroy(__root());
+    size() = 0;
+    __begin_node() = __end_node();
+    __end_node()->__left_ = nullptr;
+}
+
+// Find lower_bound place to insert
+// Set __parent to parent of null leaf
+// Return reference to null leaf
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::__node_base::pointer&
+__tree<_Tp, _Compare, _Allocator>::__find_leaf_low(typename __node_base::pointer& __parent,
+                                                   const value_type& __v)
+{
+    __node_pointer __nd = __root();
+    if (__nd != nullptr)
+    {
+        while (true)
+        {
+            if (value_comp()(__nd->__value_, __v))
+            {
+                if (__nd->__right_ != nullptr)
+                    __nd = static_cast<__node_pointer>(__nd->__right_);
+                else
+                {
+                    __parent = static_cast<__node_base_pointer>(__nd);
+                    return __parent->__right_;
+                }
+            }
+            else
+            {
+                if (__nd->__left_ != nullptr)
+                    __nd = static_cast<__node_pointer>(__nd->__left_);
+                else
+                {
+                    __parent = static_cast<__node_base_pointer>(__nd);
+                    return __parent->__left_;
+                }
+            }
+        }
+    }
+    __parent = static_cast<__node_base_pointer>(__end_node());
+    return __parent->__left_;
+}
+
+// Find upper_bound place to insert
+// Set __parent to parent of null leaf
+// Return reference to null leaf
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::__node_base::pointer&
+__tree<_Tp, _Compare, _Allocator>::__find_leaf_high(typename __node_base::pointer& __parent,
+                                                    const value_type& __v)
+{
+    __node_pointer __nd = __root();
+    if (__nd != nullptr)
+    {
+        while (true)
+        {
+            if (value_comp()(__v, __nd->__value_))
+            {
+                if (__nd->__left_ != nullptr)
+                    __nd = static_cast<__node_pointer>(__nd->__left_);
+                else
+                {
+                    __parent = static_cast<__node_base_pointer>(__nd);
+                    return __parent->__left_;
+                }
+            }
+            else
+            {
+                if (__nd->__right_ != nullptr)
+                    __nd = static_cast<__node_pointer>(__nd->__right_);
+                else
+                {
+                    __parent = static_cast<__node_base_pointer>(__nd);
+                    return __parent->__right_;
+                }
+            }
+        }
+    }
+    __parent = static_cast<__node_base_pointer>(__end_node());
+    return __parent->__left_;
+}
+
+// Find leaf place to insert closest to __hint
+// First check prior to __hint.
+// Next check after __hint.
+// Next do O(log N) search.
+// Set __parent to parent of null leaf
+// Return reference to null leaf
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::__node_base::pointer&
+__tree<_Tp, _Compare, _Allocator>::__find_leaf(const_iterator __hint,
+                                               typename __node_base::pointer& __parent,
+                                               const value_type& __v)
+{
+    if (__hint == end() || !value_comp()(*__hint, __v))  // check before
+    {
+        // __v <= *__hint
+        const_iterator __prior = __hint;
+        if (__prior == begin() || !value_comp()(__v, *--__prior))
+        {
+            // *prev(__hint) <= __v <= *__hint
+            if (__hint.__ptr_->__left_ == nullptr)
+            {
+                __parent = static_cast<__node_base_pointer>(__hint.__ptr_);
+                return __parent->__left_;
+            }
+            else
+            {
+                __parent = static_cast<__node_base_pointer>(__prior.__ptr_);
+                return __parent->__right_;
+            }
+        }
+        // __v < *prev(__hint)
+        return __find_leaf_high(__parent, __v);
+    }
+    // else __v > *__hint
+    return __find_leaf_low(__parent, __v);
+}
+
+// Find place to insert if __v doesn't exist
+// Set __parent to parent of null leaf
+// Return reference to null leaf
+// If __v exists, set parent to node of __v and return reference to node of __v
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::__node_base::pointer&
+__tree<_Tp, _Compare, _Allocator>::__find_equal(typename __node_base::pointer& __parent,
+                                                const _Key& __v)
+{
+    __node_pointer __nd = __root();
+    if (__nd != nullptr)
+    {
+        while (true)
+        {
+            if (value_comp()(__v, __nd->__value_))
+            {
+                if (__nd->__left_ != nullptr)
+                    __nd = static_cast<__node_pointer>(__nd->__left_);
+                else
+                {
+                    __parent = static_cast<__node_base_pointer>(__nd);
+                    return __parent->__left_;
+                }
+            }
+            else if (value_comp()(__nd->__value_, __v))
+            {
+                if (__nd->__right_ != nullptr)
+                    __nd = static_cast<__node_pointer>(__nd->__right_);
+                else
+                {
+                    __parent = static_cast<__node_base_pointer>(__nd);
+                    return __parent->__right_;
+                }
+            }
+            else
+            {
+                __parent = static_cast<__node_base_pointer>(__nd);
+                return __parent;
+            }
+        }
+    }
+    __parent = static_cast<__node_base_pointer>(__end_node());
+    return __parent->__left_;
+}
+
+// Find place to insert if __v doesn't exist
+// First check prior to __hint.
+// Next check after __hint.
+// Next do O(log N) search.
+// Set __parent to parent of null leaf
+// Return reference to null leaf
+// If __v exists, set parent to node of __v and return reference to node of __v
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::__node_base::pointer&
+__tree<_Tp, _Compare, _Allocator>::__find_equal(const_iterator __hint,
+                                                typename __node_base::pointer& __parent,
+                                                const _Key& __v)
+{
+    if (__hint == end() || value_comp()(__v, *__hint))  // check before
+    {
+        // __v < *__hint
+        const_iterator __prior = __hint;
+        if (__prior == begin() || value_comp()(*--__prior, __v))
+        {
+            // *prev(__hint) < __v < *__hint
+            if (__hint.__ptr_->__left_ == nullptr)
+            {
+                __parent = static_cast<__node_base_pointer>(__hint.__ptr_);
+                return __parent->__left_;
+            }
+            else
+            {
+                __parent = static_cast<__node_base_pointer>(__prior.__ptr_);
+                return __parent->__right_;
+            }
+        }
+        // __v <= *prev(__hint)
+        return __find_equal(__parent, __v);
+    }
+    else if (value_comp()(*__hint, __v))  // check after
+    {
+        // *__hint < __v
+        const_iterator __next = _VSTD::next(__hint);
+        if (__next == end() || value_comp()(__v, *__next))
+        {
+            // *__hint < __v < *_VSTD::next(__hint)
+            if (__hint.__ptr_->__right_ == nullptr)
+            {
+                __parent = static_cast<__node_base_pointer>(__hint.__ptr_);
+                return __parent->__right_;
+            }
+            else
+            {
+                __parent = static_cast<__node_base_pointer>(__next.__ptr_);
+                return __parent->__left_;
+            }
+        }
+        // *next(__hint) <= __v
+        return __find_equal(__parent, __v);
+    }
+    // else __v == *__hint
+    __parent = static_cast<__node_base_pointer>(__hint.__ptr_);
+    return __parent;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+void
+__tree<_Tp, _Compare, _Allocator>::__insert_node_at(__node_base_pointer __parent,
+                                                    __node_base_pointer& __child,
+                                                    __node_base_pointer __new_node)
+{
+    __new_node->__left_   = nullptr;
+    __new_node->__right_  = nullptr;
+    __new_node->__parent_ = __parent;
+    __child = __new_node;
+    if (__begin_node()->__left_ != nullptr)
+        __begin_node() = static_cast<__node_pointer>(__begin_node()->__left_);
+    __tree_balance_after_insert(__end_node()->__left_, __child);
+    ++size();
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class ..._Args>
+typename __tree<_Tp, _Compare, _Allocator>::__node_holder
+__tree<_Tp, _Compare, _Allocator>::__construct_node(_Args&& ...__args)
+{
+    __node_allocator& __na = __node_alloc();
+    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_), _VSTD::forward<_Args>(__args)...);
+    __h.get_deleter().__value_constructed = true;
+    return __h;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class... _Args>
+pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
+__tree<_Tp, _Compare, _Allocator>::__emplace_unique(_Args&&... __args)
+{
+    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_equal(__parent, __h->__value_);
+    __node_pointer __r = static_cast<__node_pointer>(__child);
+    bool __inserted = false;
+    if (__child == nullptr)
+    {
+        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
+        __r = __h.release();
+        __inserted = true;
+    }
+    return pair<iterator, bool>(iterator(__r), __inserted);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class... _Args>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__emplace_hint_unique(const_iterator __p, _Args&&... __args)
+{
+    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_equal(__p, __parent, __h->__value_);
+    __node_pointer __r = static_cast<__node_pointer>(__child);
+    if (__child == nullptr)
+    {
+        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
+        __r = __h.release();
+    }
+    return iterator(__r);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class... _Args>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__emplace_multi(_Args&&... __args)
+{
+    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_leaf_high(__parent, __h->__value_);
+    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
+    return iterator(static_cast<__node_pointer>(__h.release()));
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class... _Args>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__emplace_hint_multi(const_iterator __p,
+                                                        _Args&&... __args)
+{
+    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_leaf(__p, __parent, __h->__value_);
+    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
+    return iterator(static_cast<__node_pointer>(__h.release()));
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Vp>
+pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
+__tree<_Tp, _Compare, _Allocator>::__insert_unique(_Vp&& __v)
+{
+    __node_holder __h = __construct_node(_VSTD::forward<_Vp>(__v));
+    pair<iterator, bool> __r = __node_insert_unique(__h.get());
+    if (__r.second)
+        __h.release();
+    return __r;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Vp>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__insert_unique(const_iterator __p, _Vp&& __v)
+{
+    __node_holder __h = __construct_node(_VSTD::forward<_Vp>(__v));
+    iterator __r = __node_insert_unique(__p, __h.get());
+    if (__r.__ptr_ == __h.get())
+        __h.release();
+    return __r;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Vp>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__insert_multi(_Vp&& __v)
+{
+    __node_holder __h = __construct_node(_VSTD::forward<_Vp>(__v));
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_leaf_high(__parent, __h->__value_);
+    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
+    return iterator(__h.release());
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Vp>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__insert_multi(const_iterator __p, _Vp&& __v)
+{
+    __node_holder __h = __construct_node(_VSTD::forward<_Vp>(__v));
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_leaf(__p, __parent, __h->__value_);
+    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
+    return iterator(__h.release());
+}
+
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::__node_holder
+__tree<_Tp, _Compare, _Allocator>::__construct_node(const value_type& __v)
+{
+    __node_allocator& __na = __node_alloc();
+    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_), __v);
+    __h.get_deleter().__value_constructed = true;
+    return _VSTD::move(__h);  // explicitly moved for C++03
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Compare, class _Allocator>
+pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
+__tree<_Tp, _Compare, _Allocator>::__insert_unique(const value_type& __v)
+{
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_equal(__parent, __v);
+    __node_pointer __r = static_cast<__node_pointer>(__child);
+    bool __inserted = false;
+    if (__child == nullptr)
+    {
+        __node_holder __h = __construct_node(__v);
+        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
+        __r = __h.release();
+        __inserted = true;
+    }
+    return pair<iterator, bool>(iterator(__r), __inserted);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__insert_unique(const_iterator __p, const value_type& __v)
+{
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_equal(__p, __parent, __v);
+    __node_pointer __r = static_cast<__node_pointer>(__child);
+    if (__child == nullptr)
+    {
+        __node_holder __h = __construct_node(__v);
+        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
+        __r = __h.release();
+    }
+    return iterator(__r);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__insert_multi(const value_type& __v)
+{
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_leaf_high(__parent, __v);
+    __node_holder __h = __construct_node(__v);
+    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
+    return iterator(__h.release());
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__insert_multi(const_iterator __p, const value_type& __v)
+{
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_leaf(__p, __parent, __v);
+    __node_holder __h = __construct_node(__v);
+    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
+    return iterator(__h.release());
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
+__tree<_Tp, _Compare, _Allocator>::__node_insert_unique(__node_pointer __nd)
+{
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_equal(__parent, __nd->__value_);
+    __node_pointer __r = static_cast<__node_pointer>(__child);
+    bool __inserted = false;
+    if (__child == nullptr)
+    {
+        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd));
+        __r = __nd;
+        __inserted = true;
+    }
+    return pair<iterator, bool>(iterator(__r), __inserted);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__node_insert_unique(const_iterator __p,
+                                                        __node_pointer __nd)
+{
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_equal(__p, __parent, __nd->__value_);
+    __node_pointer __r = static_cast<__node_pointer>(__child);
+    if (__child == nullptr)
+    {
+        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd));
+        __r = __nd;
+    }
+    return iterator(__r);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__node_insert_multi(__node_pointer __nd)
+{
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_leaf_high(__parent, __nd->__value_);
+    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd));
+    return iterator(__nd);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__node_insert_multi(const_iterator __p,
+                                                       __node_pointer __nd)
+{
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_leaf(__p, __parent, __nd->__value_);
+    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd));
+    return iterator(__nd);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::erase(const_iterator __p)
+{
+    __node_pointer __np = __p.__ptr_;
+    iterator __r(__np);
+    ++__r;
+    if (__begin_node() == __np)
+        __begin_node() = __r.__ptr_;
+    --size();
+    __node_allocator& __na = __node_alloc();
+    __tree_remove(__end_node()->__left_,
+                  static_cast<__node_base_pointer>(__np));
+    __node_traits::destroy(__na, const_cast<value_type*>(_VSTD::addressof(*__p)));
+    __node_traits::deallocate(__na, __np, 1);
+    return __r;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::erase(const_iterator __f, const_iterator __l)
+{
+    while (__f != __l)
+        __f = erase(__f);
+    return iterator(__l.__ptr_);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::size_type
+__tree<_Tp, _Compare, _Allocator>::__erase_unique(const _Key& __k)
+{
+    iterator __i = find(__k);
+    if (__i == end())
+        return 0;
+    erase(__i);
+    return 1;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::size_type
+__tree<_Tp, _Compare, _Allocator>::__erase_multi(const _Key& __k)
+{
+    pair<iterator, iterator> __p = __equal_range_multi(__k);
+    size_type __r = 0;
+    for (; __p.first != __p.second; ++__r)
+        __p.first = erase(__p.first);
+    return __r;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::find(const _Key& __v)
+{
+    iterator __p = __lower_bound(__v, __root(), __end_node());
+    if (__p != end() && !value_comp()(__v, *__p))
+        return __p;
+    return end();
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::const_iterator
+__tree<_Tp, _Compare, _Allocator>::find(const _Key& __v) const
+{
+    const_iterator __p = __lower_bound(__v, __root(), __end_node());
+    if (__p != end() && !value_comp()(__v, *__p))
+        return __p;
+    return end();
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::size_type
+__tree<_Tp, _Compare, _Allocator>::__count_unique(const _Key& __k) const
+{
+    __node_const_pointer __result = __end_node();
+    __node_const_pointer __rt = __root();
+    while (__rt != nullptr)
+    {
+        if (value_comp()(__k, __rt->__value_))
+        {
+            __result = __rt;
+            __rt = static_cast<__node_const_pointer>(__rt->__left_);
+        }
+        else if (value_comp()(__rt->__value_, __k))
+            __rt = static_cast<__node_const_pointer>(__rt->__right_);
+        else
+            return 1;
+    }
+    return 0;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::size_type
+__tree<_Tp, _Compare, _Allocator>::__count_multi(const _Key& __k) const
+{
+    __node_const_pointer __result = __end_node();
+    __node_const_pointer __rt = __root();
+    while (__rt != nullptr)
+    {
+        if (value_comp()(__k, __rt->__value_))
+        {
+            __result = __rt;
+            __rt = static_cast<__node_const_pointer>(__rt->__left_);
+        }
+        else if (value_comp()(__rt->__value_, __k))
+            __rt = static_cast<__node_const_pointer>(__rt->__right_);
+        else
+            return _VSTD::distance(
+                __lower_bound(__k, static_cast<__node_const_pointer>(__rt->__left_), __rt),
+                __upper_bound(__k, static_cast<__node_const_pointer>(__rt->__right_), __result)
+            );
+    }
+    return 0;
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__lower_bound(const _Key& __v,
+                                                 __node_pointer __root,
+                                                 __node_pointer __result)
+{
+    while (__root != nullptr)
+    {
+        if (!value_comp()(__root->__value_, __v))
+        {
+            __result = __root;
+            __root = static_cast<__node_pointer>(__root->__left_);
+        }
+        else
+            __root = static_cast<__node_pointer>(__root->__right_);
+    }
+    return iterator(__result);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::const_iterator
+__tree<_Tp, _Compare, _Allocator>::__lower_bound(const _Key& __v,
+                                                 __node_const_pointer __root,
+                                                 __node_const_pointer __result) const
+{
+    while (__root != nullptr)
+    {
+        if (!value_comp()(__root->__value_, __v))
+        {
+            __result = __root;
+            __root = static_cast<__node_const_pointer>(__root->__left_);
+        }
+        else
+            __root = static_cast<__node_const_pointer>(__root->__right_);
+    }
+    return const_iterator(__result);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::iterator
+__tree<_Tp, _Compare, _Allocator>::__upper_bound(const _Key& __v,
+                                                 __node_pointer __root,
+                                                 __node_pointer __result)
+{
+    while (__root != nullptr)
+    {
+        if (value_comp()(__v, __root->__value_))
+        {
+            __result = __root;
+            __root = static_cast<__node_pointer>(__root->__left_);
+        }
+        else
+            __root = static_cast<__node_pointer>(__root->__right_);
+    }
+    return iterator(__result);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+typename __tree<_Tp, _Compare, _Allocator>::const_iterator
+__tree<_Tp, _Compare, _Allocator>::__upper_bound(const _Key& __v,
+                                                 __node_const_pointer __root,
+                                                 __node_const_pointer __result) const
+{
+    while (__root != nullptr)
+    {
+        if (value_comp()(__v, __root->__value_))
+        {
+            __result = __root;
+            __root = static_cast<__node_const_pointer>(__root->__left_);
+        }
+        else
+            __root = static_cast<__node_const_pointer>(__root->__right_);
+    }
+    return const_iterator(__result);
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+pair<typename __tree<_Tp, _Compare, _Allocator>::iterator,
+     typename __tree<_Tp, _Compare, _Allocator>::iterator>
+__tree<_Tp, _Compare, _Allocator>::__equal_range_unique(const _Key& __k)
+{
+    typedef pair<iterator, iterator> _Pp;
+    __node_pointer __result = __end_node();
+    __node_pointer __rt = __root();
+    while (__rt != nullptr)
+    {
+        if (value_comp()(__k, __rt->__value_))
+        {
+            __result = __rt;
+            __rt = static_cast<__node_pointer>(__rt->__left_);
+        }
+        else if (value_comp()(__rt->__value_, __k))
+            __rt = static_cast<__node_pointer>(__rt->__right_);
+        else
+            return _Pp(iterator(__rt),
+                      iterator(
+                          __rt->__right_ != nullptr ?
+                              static_cast<__node_pointer>(__tree_min(__rt->__right_))
+                            : __result));
+    }
+    return _Pp(iterator(__result), iterator(__result));
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+pair<typename __tree<_Tp, _Compare, _Allocator>::const_iterator,
+     typename __tree<_Tp, _Compare, _Allocator>::const_iterator>
+__tree<_Tp, _Compare, _Allocator>::__equal_range_unique(const _Key& __k) const
+{
+    typedef pair<const_iterator, const_iterator> _Pp;
+    __node_const_pointer __result = __end_node();
+    __node_const_pointer __rt = __root();
+    while (__rt != nullptr)
+    {
+        if (value_comp()(__k, __rt->__value_))
+        {
+            __result = __rt;
+            __rt = static_cast<__node_const_pointer>(__rt->__left_);
+        }
+        else if (value_comp()(__rt->__value_, __k))
+            __rt = static_cast<__node_const_pointer>(__rt->__right_);
+        else
+            return _Pp(const_iterator(__rt),
+                      const_iterator(
+                          __rt->__right_ != nullptr ?
+                              static_cast<__node_const_pointer>(__tree_min(__rt->__right_))
+                            : __result));
+    }
+    return _Pp(const_iterator(__result), const_iterator(__result));
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+pair<typename __tree<_Tp, _Compare, _Allocator>::iterator,
+     typename __tree<_Tp, _Compare, _Allocator>::iterator>
+__tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k)
+{
+    typedef pair<iterator, iterator> _Pp;
+    __node_pointer __result = __end_node();
+    __node_pointer __rt = __root();
+    while (__rt != nullptr)
+    {
+        if (value_comp()(__k, __rt->__value_))
+        {
+            __result = __rt;
+            __rt = static_cast<__node_pointer>(__rt->__left_);
+        }
+        else if (value_comp()(__rt->__value_, __k))
+            __rt = static_cast<__node_pointer>(__rt->__right_);
+        else
+            return _Pp(__lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), __rt),
+                      __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result));
+    }
+    return _Pp(iterator(__result), iterator(__result));
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+template <class _Key>
+pair<typename __tree<_Tp, _Compare, _Allocator>::const_iterator,
+     typename __tree<_Tp, _Compare, _Allocator>::const_iterator>
+__tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k) const
+{
+    typedef pair<const_iterator, const_iterator> _Pp;
+    __node_const_pointer __result = __end_node();
+    __node_const_pointer __rt = __root();
+    while (__rt != nullptr)
+    {
+        if (value_comp()(__k, __rt->__value_))
+        {
+            __result = __rt;
+            __rt = static_cast<__node_const_pointer>(__rt->__left_);
+        }
+        else if (value_comp()(__rt->__value_, __k))
+            __rt = static_cast<__node_const_pointer>(__rt->__right_);
+        else
+            return _Pp(__lower_bound(__k, static_cast<__node_const_pointer>(__rt->__left_), __rt),
+                      __upper_bound(__k, static_cast<__node_const_pointer>(__rt->__right_), __result));
+    }
+    return _Pp(const_iterator(__result), const_iterator(__result));
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+typename __tree<_Tp, _Compare, _Allocator>::__node_holder
+__tree<_Tp, _Compare, _Allocator>::remove(const_iterator __p) _NOEXCEPT
+{
+    __node_pointer __np = __p.__ptr_;
+    if (__begin_node() == __np)
+    {
+        if (__np->__right_ != nullptr)
+            __begin_node() = static_cast<__node_pointer>(__np->__right_);
+        else
+            __begin_node() = static_cast<__node_pointer>(__np->__parent_);
+    }
+    --size();
+    __tree_remove(__end_node()->__left_,
+                  static_cast<__node_base_pointer>(__np));
+    return __node_holder(__np, _Dp(__node_alloc(), true));
+}
+
+template <class _Tp, class _Compare, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(__tree<_Tp, _Compare, _Allocator>& __x,
+     __tree<_Tp, _Compare, _Allocator>& __y)
+    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
+{
+    __x.swap(__y);
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP___TREE

diff --git a/libcxx/include/__tuple b/libcxx/include/__tuple
new file mode 100644
index 0000000..2837ce7
--- /dev/null
+++ b/libcxx/include/__tuple

@@ -0,0 +1,373 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___TUPLE
+#define _LIBCPP___TUPLE
+
+#include <__config>
+#include <cstddef>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp> class _LIBCPP_TYPE_VIS_ONLY tuple_size;
+
+template <class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY tuple_size<const _Tp>
+    : public tuple_size<_Tp> {};
+
+template <class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY tuple_size<volatile _Tp>
+    : public tuple_size<_Tp> {};
+
+template <class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY tuple_size<const volatile _Tp>
+    : public tuple_size<_Tp> {};
+
+template <size_t _Ip, class _Tp> class _LIBCPP_TYPE_VIS_ONLY tuple_element;
+
+template <size_t _Ip, class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, const _Tp>
+{
+public:
+    typedef typename add_const<typename tuple_element<_Ip, _Tp>::type>::type type;
+};
+
+template <size_t _Ip, class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, volatile _Tp>
+{
+public:
+    typedef typename add_volatile<typename tuple_element<_Ip, _Tp>::type>::type type;
+};
+
+template <size_t _Ip, class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, const volatile _Tp>
+{
+public:
+    typedef typename add_cv<typename tuple_element<_Ip, _Tp>::type>::type type;
+};
+
+template <class _Tp> struct __tuple_like : false_type {};
+
+template <class _Tp> struct __tuple_like<const _Tp> : public __tuple_like<_Tp> {};
+template <class _Tp> struct __tuple_like<volatile _Tp> : public __tuple_like<_Tp> {};
+template <class _Tp> struct __tuple_like<const volatile _Tp> : public __tuple_like<_Tp> {};
+
+// tuple specializations
+
+#if !defined(_LIBCPP_HAS_NO_VARIADICS)
+template <class ..._Tp> class _LIBCPP_TYPE_VIS_ONLY tuple;
+
+template <class... _Tp> struct __tuple_like<tuple<_Tp...> > : true_type {};
+
+template <size_t _Ip, class ..._Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+typename tuple_element<_Ip, tuple<_Tp...> >::type&
+get(tuple<_Tp...>&) _NOEXCEPT;
+
+template <size_t _Ip, class ..._Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const typename tuple_element<_Ip, tuple<_Tp...> >::type&
+get(const tuple<_Tp...>&) _NOEXCEPT;
+
+template <size_t _Ip, class ..._Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+typename tuple_element<_Ip, tuple<_Tp...> >::type&&
+get(tuple<_Tp...>&&) _NOEXCEPT;
+#endif
+
+// pair specializations
+
+template <class _T1, class _T2> struct _LIBCPP_TYPE_VIS_ONLY pair;
+
+template <class _T1, class _T2> struct __tuple_like<pair<_T1, _T2> > : true_type {};
+
+template <size_t _Ip, class _T1, class _T2>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+typename tuple_element<_Ip, pair<_T1, _T2> >::type&
+get(pair<_T1, _T2>&) _NOEXCEPT;
+
+template <size_t _Ip, class _T1, class _T2>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const typename tuple_element<_Ip, pair<_T1, _T2> >::type&
+get(const pair<_T1, _T2>&) _NOEXCEPT;
+
+#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+template <size_t _Ip, class _T1, class _T2>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
+get(pair<_T1, _T2>&&) _NOEXCEPT;
+#endif
+
+// array specializations
+
+template <class _Tp, size_t _Size> struct _LIBCPP_TYPE_VIS_ONLY array;
+
+template <class _Tp, size_t _Size> struct __tuple_like<array<_Tp, _Size> > : true_type {};
+
+template <size_t _Ip, class _Tp, size_t _Size>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_Tp&
+get(array<_Tp, _Size>&) _NOEXCEPT;
+
+template <size_t _Ip, class _Tp, size_t _Size>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const _Tp&
+get(const array<_Tp, _Size>&) _NOEXCEPT;
+
+#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+template <size_t _Ip, class _Tp, size_t _Size>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_Tp&&
+get(array<_Tp, _Size>&&) _NOEXCEPT;
+#endif
+
+#if !defined(_LIBCPP_HAS_NO_VARIADICS)
+
+// __lazy_and
+
+template <bool _Last, class ..._Preds>
+struct __lazy_and_impl;
+
+template <class ..._Preds>
+struct __lazy_and_impl<false, _Preds...> : false_type {};
+
+template <>
+struct __lazy_and_impl<true> : true_type {};
+
+template <class _Pred>
+struct __lazy_and_impl<true, _Pred> : integral_constant<bool, _Pred::type::value> {};
+
+template <class _Hp, class ..._Tp>
+struct __lazy_and_impl<true, _Hp, _Tp...> : __lazy_and_impl<_Hp::type::value, _Tp...> {};
+
+template <class _P1, class ..._Pr>
+struct __lazy_and : __lazy_and_impl<_P1::type::value, _Pr...> {};
+
+// __lazy_not
+
+template <class _Pred>
+struct __lazy_not : integral_constant<bool, !_Pred::type::value> {};
+
+// __make_tuple_indices
+
+template <size_t...> struct __tuple_indices {};
+
+template <size_t _Sp, class _IntTuple, size_t _Ep>
+struct __make_indices_imp;
+
+template <size_t _Sp, size_t ..._Indices, size_t _Ep>
+struct __make_indices_imp<_Sp, __tuple_indices<_Indices...>, _Ep>
+{
+    typedef typename __make_indices_imp<_Sp+1, __tuple_indices<_Indices..., _Sp>, _Ep>::type type;
+};
+
+template <size_t _Ep, size_t ..._Indices>
+struct __make_indices_imp<_Ep, __tuple_indices<_Indices...>, _Ep>
+{
+    typedef __tuple_indices<_Indices...> type;
+};
+
+template <size_t _Ep, size_t _Sp = 0>
+struct __make_tuple_indices
+{
+    static_assert(_Sp <= _Ep, "__make_tuple_indices input error");
+    typedef typename __make_indices_imp<_Sp, __tuple_indices<>, _Ep>::type type;
+};
+
+// __tuple_types
+
+template <class ..._Tp> struct __tuple_types {};
+
+template <size_t _Ip>
+class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, __tuple_types<> >
+{
+public:
+    static_assert(_Ip == 0, "tuple_element index out of range");
+    static_assert(_Ip != 0, "tuple_element index out of range");
+};
+
+template <class _Hp, class ..._Tp>
+class _LIBCPP_TYPE_VIS_ONLY tuple_element<0, __tuple_types<_Hp, _Tp...> >
+{
+public:
+    typedef _Hp type;
+};
+
+template <size_t _Ip, class _Hp, class ..._Tp>
+class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, __tuple_types<_Hp, _Tp...> >
+{
+public:
+    typedef typename tuple_element<_Ip-1, __tuple_types<_Tp...> >::type type;
+};
+
+template <class ..._Tp>
+class _LIBCPP_TYPE_VIS_ONLY tuple_size<__tuple_types<_Tp...> >
+    : public integral_constant<size_t, sizeof...(_Tp)>
+{
+};
+
+template <class... _Tp> struct __tuple_like<__tuple_types<_Tp...> > : true_type {};
+
+// __make_tuple_types
+
+// __make_tuple_types<_Tuple<_Types...>, _Ep, _Sp>::type is a
+// __tuple_types<_Types...> using only those _Types in the range [_Sp, _Ep).
+// _Sp defaults to 0 and _Ep defaults to tuple_size<_Tuple>.  If _Tuple is a
+// lvalue_reference type, then __tuple_types<_Types&...> is the result.
+
+template <class _TupleTypes, class _Tp, size_t _Sp, size_t _Ep>
+struct __make_tuple_types_imp;
+
+template <class ..._Types, class _Tp, size_t _Sp, size_t _Ep>
+struct __make_tuple_types_imp<__tuple_types<_Types...>, _Tp, _Sp, _Ep>
+{
+    typedef typename remove_reference<_Tp>::type _Tpr;
+    typedef typename __make_tuple_types_imp<__tuple_types<_Types...,
+                                            typename conditional<is_lvalue_reference<_Tp>::value,
+                                                typename tuple_element<_Sp, _Tpr>::type&,
+                                                typename tuple_element<_Sp, _Tpr>::type>::type>,
+                                            _Tp, _Sp+1, _Ep>::type type;
+};
+
+template <class ..._Types, class _Tp, size_t _Ep>
+struct __make_tuple_types_imp<__tuple_types<_Types...>, _Tp, _Ep, _Ep>
+{
+    typedef __tuple_types<_Types...> type;
+};
+
+template <class _Tp, size_t _Ep = tuple_size<typename remove_reference<_Tp>::type>::value, size_t _Sp = 0>
+struct __make_tuple_types
+{
+    static_assert(_Sp <= _Ep, "__make_tuple_types input error");
+    typedef typename __make_tuple_types_imp<__tuple_types<>, _Tp, _Sp, _Ep>::type type;
+};
+
+// __tuple_convertible
+
+template <class, class>
+struct __tuple_convertible_imp : public false_type {};
+
+template <class _Tp0, class ..._Tp, class _Up0, class ..._Up>
+struct __tuple_convertible_imp<__tuple_types<_Tp0, _Tp...>, __tuple_types<_Up0, _Up...> >
+    : public integral_constant<bool,
+                               is_convertible<_Tp0, _Up0>::value &&
+                               __tuple_convertible_imp<__tuple_types<_Tp...>, __tuple_types<_Up...> >::value> {};
+
+template <>
+struct __tuple_convertible_imp<__tuple_types<>, __tuple_types<> >
+    : public true_type {};
+
+template <bool, class, class>
+struct __tuple_convertible_apply : public false_type {};
+
+template <class _Tp, class _Up>
+struct __tuple_convertible_apply<true, _Tp, _Up>
+  : public __tuple_convertible_imp<
+      typename __make_tuple_types<_Tp>::type
+    , typename __make_tuple_types<_Up>::type
+    >
+{};
+
+template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value,
+                                bool = __tuple_like<_Up>::value>
+struct __tuple_convertible
+    : public false_type {};
+
+template <class _Tp, class _Up>
+struct __tuple_convertible<_Tp, _Up, true, true>
+    : public __tuple_convertible_apply<tuple_size<typename remove_reference<_Tp>::type>::value ==
+                                     tuple_size<_Up>::value, _Tp, _Up>
+{};
+
+// __tuple_constructible
+
+template <class, class>
+struct __tuple_constructible_imp : public false_type {};
+
+template <class _Tp0, class ..._Tp, class _Up0, class ..._Up>
+struct __tuple_constructible_imp<__tuple_types<_Tp0, _Tp...>, __tuple_types<_Up0, _Up...> >
+    : public integral_constant<bool,
+                               is_constructible<_Up0, _Tp0>::value &&
+                               __tuple_constructible_imp<__tuple_types<_Tp...>, __tuple_types<_Up...> >::value> {};
+
+template <>
+struct __tuple_constructible_imp<__tuple_types<>, __tuple_types<> >
+    : public true_type {};
+
+template <bool _SameSize, class, class>
+struct __tuple_constructible_apply : public false_type {};
+
+template <class _Tp, class _Up>
+struct __tuple_constructible_apply<true, _Tp, _Up>
+  : public __tuple_constructible_imp<
+      typename __make_tuple_types<_Tp>::type
+    , typename __make_tuple_types<_Up>::type
+    >
+{};
+
+template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value,
+                                bool = __tuple_like<_Up>::value>
+struct __tuple_constructible
+    : public false_type {};
+
+template <class _Tp, class _Up>
+struct __tuple_constructible<_Tp, _Up, true, true>
+    : public __tuple_constructible_apply<tuple_size<typename remove_reference<_Tp>::type>::value ==
+                                     tuple_size<_Up>::value, _Tp, _Up>
+{};
+
+// __tuple_assignable
+
+template <class, class>
+struct __tuple_assignable_imp : public false_type {};
+
+template <class _Tp0, class ..._Tp, class _Up0, class ..._Up>
+struct __tuple_assignable_imp<__tuple_types<_Tp0, _Tp...>, __tuple_types<_Up0, _Up...> >
+    : public integral_constant<bool,
+                               is_assignable<_Up0&, _Tp0>::value &&
+                               __tuple_assignable_imp<__tuple_types<_Tp...>, __tuple_types<_Up...> >::value> {};
+
+template <>
+struct __tuple_assignable_imp<__tuple_types<>, __tuple_types<> >
+    : public true_type {};
+
+template <bool, class, class>
+struct __tuple_assignable_apply : public false_type {};
+
+template <class _Tp, class _Up>
+struct __tuple_assignable_apply<true, _Tp, _Up>
+  : __tuple_assignable_imp<
+      typename __make_tuple_types<_Tp>::type
+    , typename __make_tuple_types<_Up>::type
+    >
+{};
+
+template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value,
+                                bool = __tuple_like<_Up>::value>
+struct __tuple_assignable
+    : public false_type {};
+
+template <class _Tp, class _Up>
+struct __tuple_assignable<_Tp, _Up, true, true>
+    : public __tuple_assignable_apply<tuple_size<typename remove_reference<_Tp>::type>::value ==
+                                    tuple_size<_Up>::value, _Tp, _Up>
+{};
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP___TUPLE

diff --git a/libcxx/include/__undef___deallocate b/libcxx/include/__undef___deallocate
new file mode 100644
index 0000000..2b4ad99
--- /dev/null
+++ b/libcxx/include/__undef___deallocate

@@ -0,0 +1,18 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifdef __deallocate
+#if defined(_MSC_VER) && !defined(__clang__)
+_LIBCPP_WARNING("macro __deallocate is incompatible with C++.  #undefining __deallocate")
+#else
+#warning: macro __deallocate is incompatible with C++.  #undefining __deallocate
+#endif
+#undef __deallocate
+#endif

diff --git a/libcxx/include/__undef_min_max b/libcxx/include/__undef_min_max
new file mode 100644
index 0000000..5df9412
--- /dev/null
+++ b/libcxx/include/__undef_min_max

@@ -0,0 +1,29 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifdef min
+#if defined(_MSC_VER) && ! defined(__clang__)
+_LIBCPP_WARNING("macro min is incompatible with C++.  Try #define NOMINMAX "
+                "before any Windows header. #undefing min")
+#else
+#warning: macro min is incompatible with C++.  #undefing min
+#endif
+#undef min
+#endif
+
+#ifdef max
+#if defined(_MSC_VER) && ! defined(__clang__)
+_LIBCPP_WARNING("macro max is incompatible with C++.  Try #define NOMINMAX "
+                "before any Windows header. #undefing max")
+#else
+#warning: macro max is incompatible with C++.  #undefing max
+#endif
+#undef max
+#endif

diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
new file mode 100644
index 0000000..c1635fc
--- /dev/null
+++ b/libcxx/include/algorithm

@@ -0,0 +1,5777 @@
+// -*- C++ -*-
+//===-------------------------- algorithm ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_ALGORITHM
+#define _LIBCPP_ALGORITHM
+
+/*
+    algorithm synopsis
+
+#include <initializer_list>
+
+namespace std
+{
+
+template <class InputIterator, class Predicate>
+    bool
+    all_of(InputIterator first, InputIterator last, Predicate pred);
+
+template <class InputIterator, class Predicate>
+    bool
+    any_of(InputIterator first, InputIterator last, Predicate pred);
+
+template <class InputIterator, class Predicate>
+    bool
+    none_of(InputIterator first, InputIterator last, Predicate pred);
+
+template <class InputIterator, class Function>
+    Function
+    for_each(InputIterator first, InputIterator last, Function f);
+
+template <class InputIterator, class T>
+    InputIterator
+    find(InputIterator first, InputIterator last, const T& value);
+
+template <class InputIterator, class Predicate>
+    InputIterator
+    find_if(InputIterator first, InputIterator last, Predicate pred);
+
+template<class InputIterator, class Predicate>
+    InputIterator
+    find_if_not(InputIterator first, InputIterator last, Predicate pred);
+
+template <class ForwardIterator1, class ForwardIterator2>
+    ForwardIterator1
+    find_end(ForwardIterator1 first1, ForwardIterator1 last1,
+             ForwardIterator2 first2, ForwardIterator2 last2);
+
+template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
+    ForwardIterator1
+    find_end(ForwardIterator1 first1, ForwardIterator1 last1,
+             ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
+
+template <class ForwardIterator1, class ForwardIterator2>
+    ForwardIterator1
+    find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
+                  ForwardIterator2 first2, ForwardIterator2 last2);
+
+template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
+    ForwardIterator1
+    find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
+                  ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
+
+template <class ForwardIterator>
+    ForwardIterator
+    adjacent_find(ForwardIterator first, ForwardIterator last);
+
+template <class ForwardIterator, class BinaryPredicate>
+    ForwardIterator
+    adjacent_find(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
+
+template <class InputIterator, class T>
+    typename iterator_traits<InputIterator>::difference_type
+    count(InputIterator first, InputIterator last, const T& value);
+
+template <class InputIterator, class Predicate>
+    typename iterator_traits<InputIterator>::difference_type
+    count_if(InputIterator first, InputIterator last, Predicate pred);
+
+template <class InputIterator1, class InputIterator2>
+    pair<InputIterator1, InputIterator2>
+    mismatch(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2);
+
+template <class InputIterator1, class InputIterator2>
+    pair<InputIterator1, InputIterator2>
+    mismatch(InputIterator1 first1, InputIterator1 last1, 
+             InputIterator2 first2, InputIterator2 last2); // **C++14**
+
+template <class InputIterator1, class InputIterator2, class BinaryPredicate>
+    pair<InputIterator1, InputIterator2>
+    mismatch(InputIterator1 first1, InputIterator1 last1,
+             InputIterator2 first2, BinaryPredicate pred);
+
+template <class InputIterator1, class InputIterator2, class BinaryPredicate>
+    pair<InputIterator1, InputIterator2>
+    mismatch(InputIterator1 first1, InputIterator1 last1,
+             InputIterator2 first2, InputIterator2 last2,
+             BinaryPredicate pred); // **C++14**
+
+template <class InputIterator1, class InputIterator2>
+    bool
+    equal(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2);
+
+template <class InputIterator1, class InputIterator2>
+    bool
+    equal(InputIterator1 first1, InputIterator1 last1, 
+          InputIterator2 first2, InputIterator2 last2); // **C++14**
+
+template <class InputIterator1, class InputIterator2, class BinaryPredicate>
+    bool
+    equal(InputIterator1 first1, InputIterator1 last1,
+          InputIterator2 first2, BinaryPredicate pred);
+
+template <class InputIterator1, class InputIterator2, class BinaryPredicate>
+    bool
+    equal(InputIterator1 first1, InputIterator1 last1,
+          InputIterator2 first2, InputIterator2 last2,
+          BinaryPredicate pred); // **C++14**
+
+template<class ForwardIterator1, class ForwardIterator2>
+    bool
+    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
+                   ForwardIterator2 first2);
+
+template<class ForwardIterator1, class ForwardIterator2>
+    bool
+    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
+                   ForwardIterator2 first2, ForwardIterator2 last2); // **C++14**
+
+template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
+    bool
+    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
+                   ForwardIterator2 first2, BinaryPredicate pred);
+
+template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
+    bool
+    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
+                   ForwardIterator2 first2, ForwardIterator2 last2,
+                   BinaryPredicate pred);  // **C++14**
+
+template <class ForwardIterator1, class ForwardIterator2>
+    ForwardIterator1
+    search(ForwardIterator1 first1, ForwardIterator1 last1,
+           ForwardIterator2 first2, ForwardIterator2 last2);
+
+template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
+    ForwardIterator1
+    search(ForwardIterator1 first1, ForwardIterator1 last1,
+           ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
+
+template <class ForwardIterator, class Size, class T>
+    ForwardIterator
+    search_n(ForwardIterator first, ForwardIterator last, Size count, const T& value);
+
+template <class ForwardIterator, class Size, class T, class BinaryPredicate>
+    ForwardIterator
+    search_n(ForwardIterator first, ForwardIterator last,
+             Size count, const T& value, BinaryPredicate pred);
+
+template <class InputIterator, class OutputIterator>
+    OutputIterator
+    copy(InputIterator first, InputIterator last, OutputIterator result);
+
+template<class InputIterator, class OutputIterator, class Predicate>
+    OutputIterator
+    copy_if(InputIterator first, InputIterator last,
+            OutputIterator result, Predicate pred);
+
+template<class InputIterator, class Size, class OutputIterator>
+    OutputIterator
+    copy_n(InputIterator first, Size n, OutputIterator result);
+
+template <class BidirectionalIterator1, class BidirectionalIterator2>
+    BidirectionalIterator2
+    copy_backward(BidirectionalIterator1 first, BidirectionalIterator1 last,
+                  BidirectionalIterator2 result);
+
+template <class ForwardIterator1, class ForwardIterator2>
+    ForwardIterator2
+    swap_ranges(ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2);
+
+template <class ForwardIterator1, class ForwardIterator2>
+    void
+    iter_swap(ForwardIterator1 a, ForwardIterator2 b);
+
+template <class InputIterator, class OutputIterator, class UnaryOperation>
+    OutputIterator
+    transform(InputIterator first, InputIterator last, OutputIterator result, UnaryOperation op);
+
+template <class InputIterator1, class InputIterator2, class OutputIterator, class BinaryOperation>
+    OutputIterator
+    transform(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2,
+              OutputIterator result, BinaryOperation binary_op);
+
+template <class ForwardIterator, class T>
+    void
+    replace(ForwardIterator first, ForwardIterator last, const T& old_value, const T& new_value);
+
+template <class ForwardIterator, class Predicate, class T>
+    void
+    replace_if(ForwardIterator first, ForwardIterator last, Predicate pred, const T& new_value);
+
+template <class InputIterator, class OutputIterator, class T>
+    OutputIterator
+    replace_copy(InputIterator first, InputIterator last, OutputIterator result,
+                 const T& old_value, const T& new_value);
+
+template <class InputIterator, class OutputIterator, class Predicate, class T>
+    OutputIterator
+    replace_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred, const T& new_value);
+
+template <class ForwardIterator, class T>
+    void
+    fill(ForwardIterator first, ForwardIterator last, const T& value);
+
+template <class OutputIterator, class Size, class T>
+    OutputIterator
+    fill_n(OutputIterator first, Size n, const T& value);
+
+template <class ForwardIterator, class Generator>
+    void
+    generate(ForwardIterator first, ForwardIterator last, Generator gen);
+
+template <class OutputIterator, class Size, class Generator>
+    OutputIterator
+    generate_n(OutputIterator first, Size n, Generator gen);
+
+template <class ForwardIterator, class T>
+    ForwardIterator
+    remove(ForwardIterator first, ForwardIterator last, const T& value);
+
+template <class ForwardIterator, class Predicate>
+    ForwardIterator
+    remove_if(ForwardIterator first, ForwardIterator last, Predicate pred);
+
+template <class InputIterator, class OutputIterator, class T>
+    OutputIterator
+    remove_copy(InputIterator first, InputIterator last, OutputIterator result, const T& value);
+
+template <class InputIterator, class OutputIterator, class Predicate>
+    OutputIterator
+    remove_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred);
+
+template <class ForwardIterator>
+    ForwardIterator
+    unique(ForwardIterator first, ForwardIterator last);
+
+template <class ForwardIterator, class BinaryPredicate>
+    ForwardIterator
+    unique(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
+
+template <class InputIterator, class OutputIterator>
+    OutputIterator
+    unique_copy(InputIterator first, InputIterator last, OutputIterator result);
+
+template <class InputIterator, class OutputIterator, class BinaryPredicate>
+    OutputIterator
+    unique_copy(InputIterator first, InputIterator last, OutputIterator result, BinaryPredicate pred);
+
+template <class BidirectionalIterator>
+    void
+    reverse(BidirectionalIterator first, BidirectionalIterator last);
+
+template <class BidirectionalIterator, class OutputIterator>
+    OutputIterator
+    reverse_copy(BidirectionalIterator first, BidirectionalIterator last, OutputIterator result);
+
+template <class ForwardIterator>
+    ForwardIterator
+    rotate(ForwardIterator first, ForwardIterator middle, ForwardIterator last);
+
+template <class ForwardIterator, class OutputIterator>
+    OutputIterator
+    rotate_copy(ForwardIterator first, ForwardIterator middle, ForwardIterator last, OutputIterator result);
+
+template <class RandomAccessIterator>
+    void
+    random_shuffle(RandomAccessIterator first, RandomAccessIterator last); // deprecated in C++14
+
+template <class RandomAccessIterator, class RandomNumberGenerator>
+    void
+    random_shuffle(RandomAccessIterator first, RandomAccessIterator last,
+                   RandomNumberGenerator& rand);  // deprecated in C++14
+
+template<class RandomAccessIterator, class UniformRandomNumberGenerator>
+    void shuffle(RandomAccessIterator first, RandomAccessIterator last,
+                 UniformRandomNumberGenerator&& g);
+
+template <class InputIterator, class Predicate>
+    bool
+    is_partitioned(InputIterator first, InputIterator last, Predicate pred);
+
+template <class ForwardIterator, class Predicate>
+    ForwardIterator
+    partition(ForwardIterator first, ForwardIterator last, Predicate pred);
+
+template <class InputIterator, class OutputIterator1,
+          class OutputIterator2, class Predicate>
+    pair<OutputIterator1, OutputIterator2>
+    partition_copy(InputIterator first, InputIterator last,
+                   OutputIterator1 out_true, OutputIterator2 out_false,
+                   Predicate pred);
+
+template <class ForwardIterator, class Predicate>
+    ForwardIterator
+    stable_partition(ForwardIterator first, ForwardIterator last, Predicate pred);
+
+template<class ForwardIterator, class Predicate>
+    ForwardIterator
+    partition_point(ForwardIterator first, ForwardIterator last, Predicate pred);
+
+template <class ForwardIterator>
+    bool
+    is_sorted(ForwardIterator first, ForwardIterator last);
+
+template <class ForwardIterator, class Compare>
+    bool
+    is_sorted(ForwardIterator first, ForwardIterator last, Compare comp);
+
+template<class ForwardIterator>
+    ForwardIterator
+    is_sorted_until(ForwardIterator first, ForwardIterator last);
+
+template <class ForwardIterator, class Compare>
+    ForwardIterator
+    is_sorted_until(ForwardIterator first, ForwardIterator last, Compare comp);
+
+template <class RandomAccessIterator>
+    void
+    sort(RandomAccessIterator first, RandomAccessIterator last);
+
+template <class RandomAccessIterator, class Compare>
+    void
+    sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
+
+template <class RandomAccessIterator>
+    void
+    stable_sort(RandomAccessIterator first, RandomAccessIterator last);
+
+template <class RandomAccessIterator, class Compare>
+    void
+    stable_sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
+
+template <class RandomAccessIterator>
+    void
+    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last);
+
+template <class RandomAccessIterator, class Compare>
+    void
+    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last, Compare comp);
+
+template <class InputIterator, class RandomAccessIterator>
+    RandomAccessIterator
+    partial_sort_copy(InputIterator first, InputIterator last,
+                      RandomAccessIterator result_first, RandomAccessIterator result_last);
+
+template <class InputIterator, class RandomAccessIterator, class Compare>
+    RandomAccessIterator
+    partial_sort_copy(InputIterator first, InputIterator last,
+                      RandomAccessIterator result_first, RandomAccessIterator result_last, Compare comp);
+
+template <class RandomAccessIterator>
+    void
+    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last);
+
+template <class RandomAccessIterator, class Compare>
+    void
+    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last, Compare comp);
+
+template <class ForwardIterator, class T>
+    ForwardIterator
+    lower_bound(ForwardIterator first, ForwardIterator last, const T& value);
+
+template <class ForwardIterator, class T, class Compare>
+    ForwardIterator
+    lower_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
+
+template <class ForwardIterator, class T>
+    ForwardIterator
+    upper_bound(ForwardIterator first, ForwardIterator last, const T& value);
+
+template <class ForwardIterator, class T, class Compare>
+    ForwardIterator
+    upper_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
+
+template <class ForwardIterator, class T>
+    pair<ForwardIterator, ForwardIterator>
+    equal_range(ForwardIterator first, ForwardIterator last, const T& value);
+
+template <class ForwardIterator, class T, class Compare>
+    pair<ForwardIterator, ForwardIterator>
+    equal_range(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
+
+template <class ForwardIterator, class T>
+    bool
+    binary_search(ForwardIterator first, ForwardIterator last, const T& value);
+
+template <class ForwardIterator, class T, class Compare>
+    bool
+    binary_search(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
+
+template <class InputIterator1, class InputIterator2, class OutputIterator>
+    OutputIterator
+    merge(InputIterator1 first1, InputIterator1 last1,
+          InputIterator2 first2, InputIterator2 last2, OutputIterator result);
+
+template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
+    OutputIterator
+    merge(InputIterator1 first1, InputIterator1 last1,
+          InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
+
+template <class BidirectionalIterator>
+    void
+    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last);
+
+template <class BidirectionalIterator, class Compare>
+    void
+    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last, Compare comp);
+
+template <class InputIterator1, class InputIterator2>
+    bool
+    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
+
+template <class InputIterator1, class InputIterator2, class Compare>
+    bool
+    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, Compare comp);
+
+template <class InputIterator1, class InputIterator2, class OutputIterator>
+    OutputIterator
+    set_union(InputIterator1 first1, InputIterator1 last1,
+              InputIterator2 first2, InputIterator2 last2, OutputIterator result);
+
+template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
+    OutputIterator
+    set_union(InputIterator1 first1, InputIterator1 last1,
+              InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
+
+template <class InputIterator1, class InputIterator2, class OutputIterator>
+    OutputIterator
+    set_intersection(InputIterator1 first1, InputIterator1 last1,
+                     InputIterator2 first2, InputIterator2 last2, OutputIterator result);
+
+template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
+    OutputIterator
+    set_intersection(InputIterator1 first1, InputIterator1 last1,
+                     InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
+
+template <class InputIterator1, class InputIterator2, class OutputIterator>
+    OutputIterator
+    set_difference(InputIterator1 first1, InputIterator1 last1,
+                   InputIterator2 first2, InputIterator2 last2, OutputIterator result);
+
+template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
+    OutputIterator
+    set_difference(InputIterator1 first1, InputIterator1 last1,
+                   InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
+
+template <class InputIterator1, class InputIterator2, class OutputIterator>
+    OutputIterator
+    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
+                             InputIterator2 first2, InputIterator2 last2, OutputIterator result);
+
+template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
+    OutputIterator
+    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
+                             InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
+
+template <class RandomAccessIterator>
+    void
+    push_heap(RandomAccessIterator first, RandomAccessIterator last);
+
+template <class RandomAccessIterator, class Compare>
+    void
+    push_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
+
+template <class RandomAccessIterator>
+    void
+    pop_heap(RandomAccessIterator first, RandomAccessIterator last);
+
+template <class RandomAccessIterator, class Compare>
+    void
+    pop_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
+
+template <class RandomAccessIterator>
+    void
+    make_heap(RandomAccessIterator first, RandomAccessIterator last);
+
+template <class RandomAccessIterator, class Compare>
+    void
+    make_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
+
+template <class RandomAccessIterator>
+    void
+    sort_heap(RandomAccessIterator first, RandomAccessIterator last);
+
+template <class RandomAccessIterator, class Compare>
+    void
+    sort_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
+
+template <class RandomAccessIterator>
+    bool
+    is_heap(RandomAccessIterator first, RandomAccessiterator last);
+
+template <class RandomAccessIterator, class Compare>
+    bool
+    is_heap(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
+
+template <class RandomAccessIterator>
+    RandomAccessIterator
+    is_heap_until(RandomAccessIterator first, RandomAccessiterator last);
+
+template <class RandomAccessIterator, class Compare>
+    RandomAccessIterator
+    is_heap_until(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
+
+template <class ForwardIterator>
+    ForwardIterator
+    min_element(ForwardIterator first, ForwardIterator last);  // constexpr in C++14
+
+template <class ForwardIterator, class Compare>
+    ForwardIterator
+    min_element(ForwardIterator first, ForwardIterator last, Compare comp);  // constexpr in C++14
+
+template <class T>
+    const T&
+    min(const T& a, const T& b);  // constexpr in C++14
+
+template <class T, class Compare>
+    const T&
+    min(const T& a, const T& b, Compare comp);  // constexpr in C++14
+
+template<class T>
+    T
+    min(initializer_list<T> t);  // constexpr in C++14
+
+template<class T, class Compare>
+    T
+    min(initializer_list<T> t, Compare comp);  // constexpr in C++14
+
+template <class ForwardIterator>
+    ForwardIterator
+    max_element(ForwardIterator first, ForwardIterator last);  // constexpr in C++14
+
+template <class ForwardIterator, class Compare>
+    ForwardIterator
+    max_element(ForwardIterator first, ForwardIterator last, Compare comp);  // constexpr in C++14
+
+template <class T>
+    const T&
+    max(const T& a, const T& b); // constexpr in C++14
+
+template <class T, class Compare>
+    const T&
+    max(const T& a, const T& b, Compare comp);  // constexpr in C++14
+
+template<class T>
+    T
+    max(initializer_list<T> t);  // constexpr in C++14
+
+template<class T, class Compare>
+    T
+    max(initializer_list<T> t, Compare comp);  // constexpr in C++14
+
+template<class ForwardIterator>
+    pair<ForwardIterator, ForwardIterator>
+    minmax_element(ForwardIterator first, ForwardIterator last);   // constexpr in C++14
+
+template<class ForwardIterator, class Compare>
+    pair<ForwardIterator, ForwardIterator>
+    minmax_element(ForwardIterator first, ForwardIterator last, Compare comp);   // constexpr in C++14
+
+template<class T>
+    pair<const T&, const T&>
+    minmax(const T& a, const T& b);  // constexpr in C++14
+
+template<class T, class Compare>
+    pair<const T&, const T&>
+    minmax(const T& a, const T& b, Compare comp);  // constexpr in C++14
+
+template<class T>
+    pair<T, T>
+    minmax(initializer_list<T> t);  // constexpr in C++14
+
+template<class T, class Compare>
+    pair<T, T>
+    minmax(initializer_list<T> t, Compare comp);  // constexpr in C++14
+
+template <class InputIterator1, class InputIterator2>
+    bool
+    lexicographical_compare(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
+
+template <class InputIterator1, class InputIterator2, class Compare>
+    bool
+    lexicographical_compare(InputIterator1 first1, InputIterator1 last1,
+                            InputIterator2 first2, InputIterator2 last2, Compare comp);
+
+template <class BidirectionalIterator>
+    bool
+    next_permutation(BidirectionalIterator first, BidirectionalIterator last);
+
+template <class BidirectionalIterator, class Compare>
+    bool
+    next_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
+
+template <class BidirectionalIterator>
+    bool
+    prev_permutation(BidirectionalIterator first, BidirectionalIterator last);
+
+template <class BidirectionalIterator, class Compare>
+    bool
+    prev_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
+
+}  // std
+
+*/
+
+#include <__config>
+#include <initializer_list>
+#include <type_traits>
+#include <cstring>
+#include <utility>
+#include <memory>
+#include <iterator>
+#include <cstddef>
+
+#if defined(__IBMCPP__)
+#include "support/ibm/support.h"
+#endif
+#if defined(_LIBCPP_MSVCRT) || defined(__MINGW32__)
+#include "support/win32/support.h"
+#endif
+
+#include <__undef_min_max>
+
+#include <__debug>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+// I'd like to replace these with _VSTD::equal_to<void>, but can't because:
+//   * That only works with C++14 and later, and
+//   * We haven't included <functional> here.
+template <class _T1, class _T2 = _T1>
+struct __equal_to
+{
+    _LIBCPP_INLINE_VISIBILITY bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
+    _LIBCPP_INLINE_VISIBILITY bool operator()(const _T1& __x, const _T2& __y) const {return __x == __y;}
+    _LIBCPP_INLINE_VISIBILITY bool operator()(const _T2& __x, const _T1& __y) const {return __x == __y;}
+    _LIBCPP_INLINE_VISIBILITY bool operator()(const _T2& __x, const _T2& __y) const {return __x == __y;}
+};
+
+template <class _T1>
+struct __equal_to<_T1, _T1>
+{
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
+};
+
+template <class _T1>
+struct __equal_to<const _T1, _T1>
+{
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
+};
+
+template <class _T1>
+struct __equal_to<_T1, const _T1>
+{
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
+};
+
+template <class _T1, class _T2 = _T1>
+struct __less
+{
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 
+    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    bool operator()(const _T1& __x, const _T2& __y) const {return __x < __y;}
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    bool operator()(const _T2& __x, const _T1& __y) const {return __x < __y;}
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    bool operator()(const _T2& __x, const _T2& __y) const {return __x < __y;}
+};
+
+template <class _T1>
+struct __less<_T1, _T1>
+{
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
+};
+
+template <class _T1>
+struct __less<const _T1, _T1>
+{
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
+};
+
+template <class _T1>
+struct __less<_T1, const _T1>
+{
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
+};
+
+template <class _Predicate>
+class __negate
+{
+private:
+    _Predicate __p_;
+public:
+    _LIBCPP_INLINE_VISIBILITY __negate() {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __negate(_Predicate __p) : __p_(__p) {}
+
+    template <class _T1>
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _T1& __x) {return !__p_(__x);}
+
+    template <class _T1, class _T2>
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _T1& __x, const _T2& __y) {return !__p_(__x, __y);}
+};
+
+#ifdef _LIBCPP_DEBUG
+
+template <class _Compare>
+struct __debug_less
+{
+    _Compare __comp_;
+    __debug_less(_Compare& __c) : __comp_(__c) {}
+    template <class _Tp, class _Up>
+    bool operator()(const _Tp& __x, const _Up& __y)
+    {
+        bool __r = __comp_(__x, __y);
+        if (__r)
+            _LIBCPP_ASSERT(!__comp_(__y, __x), "Comparator does not induce a strict weak ordering");
+        return __r;
+    }
+};
+
+#endif  // _LIBCPP_DEBUG
+
+// Precondition:  __x != 0
+inline _LIBCPP_INLINE_VISIBILITY
+unsigned
+__ctz(unsigned __x)
+{
+    return static_cast<unsigned>(__builtin_ctz(__x));
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+unsigned long
+__ctz(unsigned long __x)
+{
+    return static_cast<unsigned long>(__builtin_ctzl(__x));
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+unsigned long long
+__ctz(unsigned long long __x)
+{
+    return static_cast<unsigned long long>(__builtin_ctzll(__x));
+}
+
+// Precondition:  __x != 0
+inline _LIBCPP_INLINE_VISIBILITY
+unsigned
+__clz(unsigned __x)
+{
+    return static_cast<unsigned>(__builtin_clz(__x));
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+unsigned long
+__clz(unsigned long __x)
+{
+    return static_cast<unsigned long>(__builtin_clzl (__x));
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+unsigned long long
+__clz(unsigned long long __x)
+{
+    return static_cast<unsigned long long>(__builtin_clzll(__x));
+}
+
+inline _LIBCPP_INLINE_VISIBILITY int __pop_count(unsigned           __x) {return __builtin_popcount  (__x);}
+inline _LIBCPP_INLINE_VISIBILITY int __pop_count(unsigned      long __x) {return __builtin_popcountl (__x);}
+inline _LIBCPP_INLINE_VISIBILITY int __pop_count(unsigned long long __x) {return __builtin_popcountll(__x);}
+
+// all_of
+
+template <class _InputIterator, class _Predicate>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+all_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
+{
+    for (; __first != __last; ++__first)
+        if (!__pred(*__first))
+            return false;
+    return true;
+}
+
+// any_of
+
+template <class _InputIterator, class _Predicate>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+any_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
+{
+    for (; __first != __last; ++__first)
+        if (__pred(*__first))
+            return true;
+    return false;
+}
+
+// none_of
+
+template <class _InputIterator, class _Predicate>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+none_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
+{
+    for (; __first != __last; ++__first)
+        if (__pred(*__first))
+            return false;
+    return true;
+}
+
+// for_each
+
+template <class _InputIterator, class _Function>
+inline _LIBCPP_INLINE_VISIBILITY
+_Function
+for_each(_InputIterator __first, _InputIterator __last, _Function __f)
+{
+    for (; __first != __last; ++__first)
+        __f(*__first);
+    return _VSTD::move(__f);  // explicitly moved for (emulated) C++03
+}
+
+// find
+
+template <class _InputIterator, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_InputIterator
+find(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
+{
+    for (; __first != __last; ++__first)
+        if (*__first == __value_)
+            break;
+    return __first;
+}
+
+// find_if
+
+template <class _InputIterator, class _Predicate>
+inline _LIBCPP_INLINE_VISIBILITY
+_InputIterator
+find_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
+{
+    for (; __first != __last; ++__first)
+        if (__pred(*__first))
+            break;
+    return __first;
+}
+
+// find_if_not
+
+template<class _InputIterator, class _Predicate>
+inline _LIBCPP_INLINE_VISIBILITY
+_InputIterator
+find_if_not(_InputIterator __first, _InputIterator __last, _Predicate __pred)
+{
+    for (; __first != __last; ++__first)
+        if (!__pred(*__first))
+            break;
+    return __first;
+}
+
+// find_end
+
+template <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
+_ForwardIterator1
+__find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+           _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred,
+           forward_iterator_tag, forward_iterator_tag)
+{
+    // modeled after search algorithm
+    _ForwardIterator1 __r = __last1;  // __last1 is the "default" answer
+    if (__first2 == __last2)
+        return __r;
+    while (true)
+    {
+        while (true)
+        {
+            if (__first1 == __last1)         // if source exhausted return last correct answer
+                return __r;                  //    (or __last1 if never found)
+            if (__pred(*__first1, *__first2))
+                break;
+            ++__first1;
+        }
+        // *__first1 matches *__first2, now match elements after here
+        _ForwardIterator1 __m1 = __first1;
+        _ForwardIterator2 __m2 = __first2;
+        while (true)
+        {
+            if (++__m2 == __last2)
+            {                         // Pattern exhaused, record answer and search for another one
+                __r = __first1;
+                ++__first1;
+                break;
+            }
+            if (++__m1 == __last1)     // Source exhausted, return last answer
+                return __r;
+            if (!__pred(*__m1, *__m2))  // mismatch, restart with a new __first
+            {
+                ++__first1;
+                break;
+            }  // else there is a match, check next elements
+        }
+    }
+}
+
+template <class _BinaryPredicate, class _BidirectionalIterator1, class _BidirectionalIterator2>
+_BidirectionalIterator1
+__find_end(_BidirectionalIterator1 __first1, _BidirectionalIterator1 __last1,
+           _BidirectionalIterator2 __first2, _BidirectionalIterator2 __last2, _BinaryPredicate __pred,
+           bidirectional_iterator_tag, bidirectional_iterator_tag)
+{
+    // modeled after search algorithm (in reverse)
+    if (__first2 == __last2)
+        return __last1;  // Everything matches an empty sequence
+    _BidirectionalIterator1 __l1 = __last1;
+    _BidirectionalIterator2 __l2 = __last2;
+    --__l2;
+    while (true)
+    {
+        // Find last element in sequence 1 that matchs *(__last2-1), with a mininum of loop checks
+        while (true)
+        {
+            if (__first1 == __l1)  // return __last1 if no element matches *__first2
+                return __last1;
+            if (__pred(*--__l1, *__l2))
+                break;
+        }
+        // *__l1 matches *__l2, now match elements before here
+        _BidirectionalIterator1 __m1 = __l1;
+        _BidirectionalIterator2 __m2 = __l2;
+        while (true)
+        {
+            if (__m2 == __first2)  // If pattern exhausted, __m1 is the answer (works for 1 element pattern)
+                return __m1;
+            if (__m1 == __first1)  // Otherwise if source exhaused, pattern not found
+                return __last1;
+            if (!__pred(*--__m1, *--__m2))  // if there is a mismatch, restart with a new __l1
+            {
+                break;
+            }  // else there is a match, check next elements
+        }
+    }
+}
+
+template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
+_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator1
+__find_end(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
+           _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
+           random_access_iterator_tag, random_access_iterator_tag)
+{
+    // Take advantage of knowing source and pattern lengths.  Stop short when source is smaller than pattern
+    typename iterator_traits<_RandomAccessIterator2>::difference_type __len2 = __last2 - __first2;
+    if (__len2 == 0)
+        return __last1;
+    typename iterator_traits<_RandomAccessIterator1>::difference_type __len1 = __last1 - __first1;
+    if (__len1 < __len2)
+        return __last1;
+    const _RandomAccessIterator1 __s = __first1 + (__len2 - 1);  // End of pattern match can't go before here
+    _RandomAccessIterator1 __l1 = __last1;
+    _RandomAccessIterator2 __l2 = __last2;
+    --__l2;
+    while (true)
+    {
+        while (true)
+        {
+            if (__s == __l1)
+                return __last1;
+            if (__pred(*--__l1, *__l2))
+                break;
+        }
+        _RandomAccessIterator1 __m1 = __l1;
+        _RandomAccessIterator2 __m2 = __l2;
+        while (true)
+        {
+            if (__m2 == __first2)
+                return __m1;
+                                 // no need to check range on __m1 because __s guarantees we have enough source
+            if (!__pred(*--__m1, *--__m2))
+            {
+                break;
+            }
+        }
+    }
+}
+
+template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator1
+find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+         _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
+{
+    return _VSTD::__find_end<typename add_lvalue_reference<_BinaryPredicate>::type>
+                         (__first1, __last1, __first2, __last2, __pred,
+                          typename iterator_traits<_ForwardIterator1>::iterator_category(),
+                          typename iterator_traits<_ForwardIterator2>::iterator_category());
+}
+
+template <class _ForwardIterator1, class _ForwardIterator2>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator1
+find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+         _ForwardIterator2 __first2, _ForwardIterator2 __last2)
+{
+    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
+    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
+    return _VSTD::find_end(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
+}
+
+// find_first_of
+
+template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
+_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator1
+__find_first_of_ce(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+              _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
+{
+    for (; __first1 != __last1; ++__first1)
+        for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
+            if (__pred(*__first1, *__j))
+                return __first1;
+    return __last1;
+}
+
+
+template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator1
+find_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+              _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
+{
+    return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __pred);
+}
+
+template <class _ForwardIterator1, class _ForwardIterator2>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator1
+find_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+              _ForwardIterator2 __first2, _ForwardIterator2 __last2)
+{
+    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
+    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
+    return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
+}
+
+// adjacent_find
+
+template <class _ForwardIterator, class _BinaryPredicate>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator
+adjacent_find(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred)
+{
+    if (__first != __last)
+    {
+        _ForwardIterator __i = __first;
+        while (++__i != __last)
+        {
+            if (__pred(*__first, *__i))
+                return __first;
+            __first = __i;
+        }
+    }
+    return __last;
+}
+
+template <class _ForwardIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator
+adjacent_find(_ForwardIterator __first, _ForwardIterator __last)
+{
+    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
+    return _VSTD::adjacent_find(__first, __last, __equal_to<__v>());
+}
+
+// count
+
+template <class _InputIterator, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename iterator_traits<_InputIterator>::difference_type
+count(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
+{
+    typename iterator_traits<_InputIterator>::difference_type __r(0);
+    for (; __first != __last; ++__first)
+        if (*__first == __value_)
+            ++__r;
+    return __r;
+}
+
+// count_if
+
+template <class _InputIterator, class _Predicate>
+inline _LIBCPP_INLINE_VISIBILITY
+typename iterator_traits<_InputIterator>::difference_type
+count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
+{
+    typename iterator_traits<_InputIterator>::difference_type __r(0);
+    for (; __first != __last; ++__first)
+        if (__pred(*__first))
+            ++__r;
+    return __r;
+}
+
+// mismatch
+
+template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
+inline _LIBCPP_INLINE_VISIBILITY
+pair<_InputIterator1, _InputIterator2>
+mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
+         _InputIterator2 __first2, _BinaryPredicate __pred)
+{
+    for (; __first1 != __last1; ++__first1, (void) ++__first2)
+        if (!__pred(*__first1, *__first2))
+            break;
+    return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
+}
+
+template <class _InputIterator1, class _InputIterator2>
+inline _LIBCPP_INLINE_VISIBILITY
+pair<_InputIterator1, _InputIterator2>
+mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2)
+{
+    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
+    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
+    return _VSTD::mismatch(__first1, __last1, __first2, __equal_to<__v1, __v2>());
+}
+
+#if _LIBCPP_STD_VER > 11
+template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
+inline _LIBCPP_INLINE_VISIBILITY
+pair<_InputIterator1, _InputIterator2>
+mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
+         _InputIterator2 __first2, _InputIterator2 __last2,
+         _BinaryPredicate __pred)
+{
+    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
+        if (!__pred(*__first1, *__first2))
+            break;
+    return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
+}
+
+template <class _InputIterator1, class _InputIterator2>
+inline _LIBCPP_INLINE_VISIBILITY
+pair<_InputIterator1, _InputIterator2>
+mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
+         _InputIterator2 __first2, _InputIterator2 __last2)
+{
+    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
+    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
+    return _VSTD::mismatch(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
+}
+#endif
+
+// equal
+
+template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred)
+{
+    for (; __first1 != __last1; ++__first1, (void) ++__first2)
+        if (!__pred(*__first1, *__first2))
+            return false;
+    return true;
+}
+
+template <class _InputIterator1, class _InputIterator2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2)
+{
+    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
+    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
+    return _VSTD::equal(__first1, __last1, __first2, __equal_to<__v1, __v2>());
+}
+
+#if _LIBCPP_STD_VER > 11
+template <class _BinaryPredicate, class _InputIterator1, class _InputIterator2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+__equal(_InputIterator1 __first1, _InputIterator1 __last1, 
+        _InputIterator2 __first2, _InputIterator2 __last2, _BinaryPredicate __pred,
+        input_iterator_tag, input_iterator_tag )
+{
+    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
+        if (!__pred(*__first1, *__first2))
+            return false;
+    return __first1 == __last1 && __first2 == __last2;
+}
+
+template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+__equal(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1, 
+        _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred, 
+      random_access_iterator_tag, random_access_iterator_tag )
+{
+    if ( _VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
+        return false;
+    return _VSTD::equal<_RandomAccessIterator1, _RandomAccessIterator2,
+                        typename add_lvalue_reference<_BinaryPredicate>::type>
+                       (__first1, __last1, __first2, __pred );
+}
+
+template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+equal(_InputIterator1 __first1, _InputIterator1 __last1, 
+      _InputIterator2 __first2, _InputIterator2 __last2, _BinaryPredicate __pred )
+{
+    return _VSTD::__equal<typename add_lvalue_reference<_BinaryPredicate>::type>
+       (__first1, __last1, __first2, __last2, __pred, 
+        typename iterator_traits<_InputIterator1>::iterator_category(),
+        typename iterator_traits<_InputIterator2>::iterator_category());
+}
+
+template <class _InputIterator1, class _InputIterator2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+equal(_InputIterator1 __first1, _InputIterator1 __last1, 
+      _InputIterator2 __first2, _InputIterator2 __last2)
+{
+    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
+    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
+    return _VSTD::__equal(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>(),
+        typename iterator_traits<_InputIterator1>::iterator_category(),
+        typename iterator_traits<_InputIterator2>::iterator_category());
+}
+#endif
+
+// is_permutation
+
+template<class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
+bool
+is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+               _ForwardIterator2 __first2, _BinaryPredicate __pred)
+{
+    // shorten sequences as much as possible by lopping of any equal parts
+    for (; __first1 != __last1; ++__first1, (void) ++__first2)
+        if (!__pred(*__first1, *__first2))
+            goto __not_done;
+    return true;
+__not_done:
+    // __first1 != __last1 && *__first1 != *__first2
+    typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
+    _D1 __l1 = _VSTD::distance(__first1, __last1);
+    if (__l1 == _D1(1))
+        return false;
+    _ForwardIterator2 __last2 = _VSTD::next(__first2, __l1);
+    // For each element in [f1, l1) see if there are the same number of
+    //    equal elements in [f2, l2)
+    for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i)
+    {
+        // Have we already counted the number of *__i in [f1, l1)?
+        for (_ForwardIterator1 __j = __first1; __j != __i; ++__j)
+            if (__pred(*__j, *__i))
+                goto __next_iter;
+        {
+            // Count number of *__i in [f2, l2)
+            _D1 __c2 = 0;
+            for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
+                if (__pred(*__i, *__j))
+                    ++__c2;
+            if (__c2 == 0)
+                return false;
+            // Count number of *__i in [__i, l1) (we can start with 1)
+            _D1 __c1 = 1;
+            for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
+                if (__pred(*__i, *__j))
+                    ++__c1;
+            if (__c1 != __c2)
+                return false;
+        }
+__next_iter:;
+    }
+    return true;
+}
+
+template<class _ForwardIterator1, class _ForwardIterator2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+               _ForwardIterator2 __first2)
+{
+    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
+    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
+    return _VSTD::is_permutation(__first1, __last1, __first2, __equal_to<__v1, __v2>());
+}
+
+#if _LIBCPP_STD_VER > 11
+template<class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
+bool
+__is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+                 _ForwardIterator2 __first2, _ForwardIterator2 __last2, 
+                 _BinaryPredicate __pred,
+                 forward_iterator_tag, forward_iterator_tag )
+{
+    // shorten sequences as much as possible by lopping of any equal parts
+    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
+        if (!__pred(*__first1, *__first2))
+            goto __not_done;
+    return __first1 == __last1 && __first2 == __last2;
+__not_done:
+    // __first1 != __last1 && __first2 != __last2 && *__first1 != *__first2
+    typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
+    _D1 __l1 = _VSTD::distance(__first1, __last1);
+
+    typedef typename iterator_traits<_ForwardIterator2>::difference_type _D2;
+    _D2 __l2 = _VSTD::distance(__first2, __last2);
+    if (__l1 != __l2)
+        return false;
+
+    // For each element in [f1, l1) see if there are the same number of
+    //    equal elements in [f2, l2)
+    for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i)
+    {
+        // Have we already counted the number of *__i in [f1, l1)?
+        for (_ForwardIterator1 __j = __first1; __j != __i; ++__j)
+            if (__pred(*__j, *__i))
+                goto __next_iter;
+        {
+            // Count number of *__i in [f2, l2)
+            _D1 __c2 = 0;
+            for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
+                if (__pred(*__i, *__j))
+                    ++__c2;
+            if (__c2 == 0)
+                return false;
+            // Count number of *__i in [__i, l1) (we can start with 1)
+            _D1 __c1 = 1;
+            for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
+                if (__pred(*__i, *__j))
+                    ++__c1;
+            if (__c1 != __c2)
+                return false;
+        }
+__next_iter:;
+    }
+    return true;
+}
+
+template<class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
+bool
+__is_permutation(_RandomAccessIterator1 __first1, _RandomAccessIterator2 __last1,
+               _RandomAccessIterator1 __first2, _RandomAccessIterator2 __last2, 
+               _BinaryPredicate __pred,
+               random_access_iterator_tag, random_access_iterator_tag )
+{
+    if ( _VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
+        return false;
+    return _VSTD::is_permutation<_RandomAccessIterator1, _RandomAccessIterator2,
+                                 typename add_lvalue_reference<_BinaryPredicate>::type>
+                                (__first1, __last1, __first2, __pred );
+}
+
+template<class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+               _ForwardIterator2 __first2, _ForwardIterator2 __last2,
+               _BinaryPredicate __pred )
+{
+    return _VSTD::__is_permutation<typename add_lvalue_reference<_BinaryPredicate>::type>
+       (__first1, __last1, __first2, __last2, __pred,
+        typename iterator_traits<_ForwardIterator1>::iterator_category(),
+        typename iterator_traits<_ForwardIterator2>::iterator_category());
+}
+
+template<class _ForwardIterator1, class _ForwardIterator2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+               _ForwardIterator2 __first2, _ForwardIterator2 __last2)
+{
+    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
+    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
+    return _VSTD::__is_permutation(__first1, __last1, __first2, __last2,
+        __equal_to<__v1, __v2>(),
+        typename iterator_traits<_ForwardIterator1>::iterator_category(),
+        typename iterator_traits<_ForwardIterator2>::iterator_category());
+}
+#endif
+
+// search
+
+template <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
+_ForwardIterator1
+__search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+         _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred,
+         forward_iterator_tag, forward_iterator_tag)
+{
+    if (__first2 == __last2)
+        return __first1;  // Everything matches an empty sequence
+    while (true)
+    {
+        // Find first element in sequence 1 that matchs *__first2, with a mininum of loop checks
+        while (true)
+        {
+            if (__first1 == __last1)  // return __last1 if no element matches *__first2
+                return __last1;
+            if (__pred(*__first1, *__first2))
+                break;
+            ++__first1;
+        }
+        // *__first1 matches *__first2, now match elements after here
+        _ForwardIterator1 __m1 = __first1;
+        _ForwardIterator2 __m2 = __first2;
+        while (true)
+        {
+            if (++__m2 == __last2)  // If pattern exhausted, __first1 is the answer (works for 1 element pattern)
+                return __first1;
+            if (++__m1 == __last1)  // Otherwise if source exhaused, pattern not found
+                return __last1;
+            if (!__pred(*__m1, *__m2))  // if there is a mismatch, restart with a new __first1
+            {
+                ++__first1;
+                break;
+            }  // else there is a match, check next elements
+        }
+    }
+}
+
+template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
+_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator1
+__search(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
+           _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
+           random_access_iterator_tag, random_access_iterator_tag)
+{
+    typedef typename std::iterator_traits<_RandomAccessIterator1>::difference_type _D1;
+    typedef typename std::iterator_traits<_RandomAccessIterator2>::difference_type _D2;
+    // Take advantage of knowing source and pattern lengths.  Stop short when source is smaller than pattern
+    _D2 __len2 = __last2 - __first2;
+    if (__len2 == 0)
+        return __first1;
+    _D1 __len1 = __last1 - __first1;
+    if (__len1 < __len2)
+        return __last1;
+    const _RandomAccessIterator1 __s = __last1 - (__len2 - 1);  // Start of pattern match can't go beyond here
+    while (true)
+    {
+#if !_LIBCPP_UNROLL_LOOPS
+        while (true)
+        {
+            if (__first1 == __s)
+                return __last1;
+            if (__pred(*__first1, *__first2))
+                break;
+            ++__first1;
+        }
+#else  // !_LIBCPP_UNROLL_LOOPS
+        for (_D1 __loop_unroll = (__s - __first1) / 4; __loop_unroll > 0; --__loop_unroll)
+        {
+            if (__pred(*__first1, *__first2))
+                goto __phase2;
+            if (__pred(*++__first1, *__first2))
+                goto __phase2;
+            if (__pred(*++__first1, *__first2))
+                goto __phase2;
+            if (__pred(*++__first1, *__first2))
+                goto __phase2;
+            ++__first1;
+        }
+        switch (__s - __first1)
+        {
+        case 3:
+            if (__pred(*__first1, *__first2))
+                break;
+            ++__first1;
+        case 2:
+            if (__pred(*__first1, *__first2))
+                break;
+            ++__first1;
+        case 1:
+            if (__pred(*__first1, *__first2))
+                break;
+        case 0:
+            return __last1;
+        }
+    __phase2:
+#endif  // !_LIBCPP_UNROLL_LOOPS
+        _RandomAccessIterator1 __m1 = __first1;
+        _RandomAccessIterator2 __m2 = __first2;
+#if !_LIBCPP_UNROLL_LOOPS
+         while (true)
+         {
+             if (++__m2 == __last2)
+                 return __first1;
+             ++__m1;          // no need to check range on __m1 because __s guarantees we have enough source
+             if (!__pred(*__m1, *__m2))
+             {
+                 ++__first1;
+                 break;
+             }
+         }
+#else  // !_LIBCPP_UNROLL_LOOPS
+        ++__m2;
+        ++__m1;
+        for (_D2 __loop_unroll = (__last2 - __m2) / 4; __loop_unroll > 0; --__loop_unroll)
+        {
+            if (!__pred(*__m1, *__m2))
+                goto __continue;
+            if (!__pred(*++__m1, *++__m2))
+                goto __continue;
+            if (!__pred(*++__m1, *++__m2))
+                goto __continue;
+            if (!__pred(*++__m1, *++__m2))
+                goto __continue;
+            ++__m1;
+            ++__m2;
+        }
+        switch (__last2 - __m2)
+        {
+        case 3:
+            if (!__pred(*__m1, *__m2))
+                break;
+            ++__m1;
+            ++__m2;
+        case 2:
+            if (!__pred(*__m1, *__m2))
+                break;
+            ++__m1;
+            ++__m2;
+        case 1:
+            if (!__pred(*__m1, *__m2))
+                break;
+        case 0:
+            return __first1;
+        }
+    __continue:
+        ++__first1;
+#endif  // !_LIBCPP_UNROLL_LOOPS
+    }
+}
+
+template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator1
+search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+       _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
+{
+    return _VSTD::__search<typename add_lvalue_reference<_BinaryPredicate>::type>
+                         (__first1, __last1, __first2, __last2, __pred,
+                          typename std::iterator_traits<_ForwardIterator1>::iterator_category(),
+                          typename std::iterator_traits<_ForwardIterator2>::iterator_category());
+}
+
+template <class _ForwardIterator1, class _ForwardIterator2>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator1
+search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
+       _ForwardIterator2 __first2, _ForwardIterator2 __last2)
+{
+    typedef typename std::iterator_traits<_ForwardIterator1>::value_type __v1;
+    typedef typename std::iterator_traits<_ForwardIterator2>::value_type __v2;
+    return _VSTD::search(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
+}
+
+// search_n
+
+template <class _BinaryPredicate, class _ForwardIterator, class _Size, class _Tp>
+_ForwardIterator
+__search_n(_ForwardIterator __first, _ForwardIterator __last,
+           _Size __count, const _Tp& __value_, _BinaryPredicate __pred, forward_iterator_tag)
+{
+    if (__count <= 0)
+        return __first;
+    while (true)
+    {
+        // Find first element in sequence that matchs __value_, with a mininum of loop checks
+        while (true)
+        {
+            if (__first == __last)  // return __last if no element matches __value_
+                return __last;
+            if (__pred(*__first, __value_))
+                break;
+            ++__first;
+        }
+        // *__first matches __value_, now match elements after here
+        _ForwardIterator __m = __first;
+        _Size __c(0);
+        while (true)
+        {
+            if (++__c == __count)  // If pattern exhausted, __first is the answer (works for 1 element pattern)
+                return __first;
+            if (++__m == __last)  // Otherwise if source exhaused, pattern not found
+                return __last;
+            if (!__pred(*__m, __value_))  // if there is a mismatch, restart with a new __first
+            {
+                __first = __m;
+                ++__first;
+                break;
+            }  // else there is a match, check next elements
+        }
+    }
+}
+
+template <class _BinaryPredicate, class _RandomAccessIterator, class _Size, class _Tp>
+_RandomAccessIterator
+__search_n(_RandomAccessIterator __first, _RandomAccessIterator __last,
+           _Size __count, const _Tp& __value_, _BinaryPredicate __pred, random_access_iterator_tag)
+{
+    if (__count <= 0)
+        return __first;
+    _Size __len = static_cast<_Size>(__last - __first);
+    if (__len < __count)
+        return __last;
+    const _RandomAccessIterator __s = __last - (__count - 1);  // Start of pattern match can't go beyond here
+    while (true)
+    {
+        // Find first element in sequence that matchs __value_, with a mininum of loop checks
+        while (true)
+        {
+            if (__first >= __s)  // return __last if no element matches __value_
+                return __last;
+            if (__pred(*__first, __value_))
+                break;
+            ++__first;
+        }
+        // *__first matches __value_, now match elements after here
+        _RandomAccessIterator __m = __first;
+        _Size __c(0);
+        while (true)
+        {
+            if (++__c == __count)  // If pattern exhausted, __first is the answer (works for 1 element pattern)
+                return __first;
+             ++__m;          // no need to check range on __m because __s guarantees we have enough source
+            if (!__pred(*__m, __value_))  // if there is a mismatch, restart with a new __first
+            {
+                __first = __m;
+                ++__first;
+                break;
+            }  // else there is a match, check next elements
+        }
+    }
+}
+
+template <class _ForwardIterator, class _Size, class _Tp, class _BinaryPredicate>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator
+search_n(_ForwardIterator __first, _ForwardIterator __last,
+         _Size __count, const _Tp& __value_, _BinaryPredicate __pred)
+{
+    return _VSTD::__search_n<typename add_lvalue_reference<_BinaryPredicate>::type>
+           (__first, __last, __convert_to_integral(__count), __value_, __pred,
+           typename iterator_traits<_ForwardIterator>::iterator_category());
+}
+
+template <class _ForwardIterator, class _Size, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator
+search_n(_ForwardIterator __first, _ForwardIterator __last, _Size __count, const _Tp& __value_)
+{
+    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
+    return _VSTD::search_n(__first, __last, __convert_to_integral(__count),
+                           __value_, __equal_to<__v, _Tp>());
+}
+
+// copy
+
+template <class _Iter>
+struct __libcpp_is_trivial_iterator
+{
+    static const bool value = is_pointer<_Iter>::value;
+};
+
+template <class _Iter>
+struct __libcpp_is_trivial_iterator<move_iterator<_Iter> >
+{
+    static const bool value = is_pointer<_Iter>::value;
+};
+
+template <class _Iter>
+struct __libcpp_is_trivial_iterator<__wrap_iter<_Iter> >
+{
+    static const bool value = is_pointer<_Iter>::value;
+};
+
+template <class _Iter>
+inline _LIBCPP_INLINE_VISIBILITY
+_Iter
+__unwrap_iter(_Iter __i)
+{
+    return __i;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_trivially_copy_assignable<_Tp>::value,
+    _Tp*
+>::type
+__unwrap_iter(move_iterator<_Tp*> __i)
+{
+    return __i.base();
+}
+
+#if _LIBCPP_DEBUG_LEVEL < 2
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_trivially_copy_assignable<_Tp>::value,
+    _Tp*
+>::type
+__unwrap_iter(__wrap_iter<_Tp*> __i)
+{
+    return __i.base();
+}
+
+#endif  // _LIBCPP_DEBUG_LEVEL < 2
+
+template <class _InputIterator, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+__copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
+{
+    for (; __first != __last; ++__first, (void) ++__result)
+        *__result = *__first;
+    return __result;
+}
+
+template <class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_same<typename remove_const<_Tp>::type, _Up>::value &&
+    is_trivially_copy_assignable<_Up>::value,
+    _Up*
+>::type
+__copy(_Tp* __first, _Tp* __last, _Up* __result)
+{
+    const size_t __n = static_cast<size_t>(__last - __first);
+    if (__n > 0)
+        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
+    return __result + __n;
+}
+
+template <class _InputIterator, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
+{
+    return _VSTD::__copy(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
+}
+
+// copy_backward
+
+template <class _BidirectionalIterator, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+__copy_backward(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
+{
+    while (__first != __last)
+        *--__result = *--__last;
+    return __result;
+}
+
+template <class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_same<typename remove_const<_Tp>::type, _Up>::value &&
+    is_trivially_copy_assignable<_Up>::value,
+    _Up*
+>::type
+__copy_backward(_Tp* __first, _Tp* __last, _Up* __result)
+{
+    const size_t __n = static_cast<size_t>(__last - __first);
+    if (__n > 0)
+    {
+        __result -= __n;
+        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
+    }
+    return __result;
+}
+
+template <class _BidirectionalIterator1, class _BidirectionalIterator2>
+inline _LIBCPP_INLINE_VISIBILITY
+_BidirectionalIterator2
+copy_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
+              _BidirectionalIterator2 __result)
+{
+    return _VSTD::__copy_backward(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
+}
+
+// copy_if
+
+template<class _InputIterator, class _OutputIterator, class _Predicate>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+copy_if(_InputIterator __first, _InputIterator __last,
+        _OutputIterator __result, _Predicate __pred)
+{
+    for (; __first != __last; ++__first)
+    {
+        if (__pred(*__first))
+        {
+            *__result = *__first;
+            ++__result;
+        }
+    }
+    return __result;
+}
+
+// copy_n
+
+template<class _InputIterator, class _Size, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    __is_input_iterator<_InputIterator>::value &&
+   !__is_random_access_iterator<_InputIterator>::value,
+    _OutputIterator
+>::type
+copy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
+{
+    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
+    _IntegralSize __n = __orig_n;
+    if (__n > 0)
+    {
+        *__result = *__first;
+        ++__result;
+        for (--__n; __n > 0; --__n)
+        {
+            ++__first;
+            *__result = *__first;
+            ++__result;
+        }
+    }
+    return __result;
+}
+
+template<class _InputIterator, class _Size, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    __is_random_access_iterator<_InputIterator>::value,
+    _OutputIterator
+>::type
+copy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
+{
+    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
+    _IntegralSize __n = __orig_n;
+    return _VSTD::copy(__first, __first + __n, __result);
+}
+
+// move
+
+template <class _InputIterator, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+__move(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
+{
+    for (; __first != __last; ++__first, (void) ++__result)
+        *__result = _VSTD::move(*__first);
+    return __result;
+}
+
+template <class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_same<typename remove_const<_Tp>::type, _Up>::value &&
+    is_trivially_copy_assignable<_Up>::value,
+    _Up*
+>::type
+__move(_Tp* __first, _Tp* __last, _Up* __result)
+{
+    const size_t __n = static_cast<size_t>(__last - __first);
+    if (__n > 0)
+        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
+    return __result + __n;
+}
+
+template <class _InputIterator, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+move(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
+{
+    return _VSTD::__move(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
+}
+
+// move_backward
+
+template <class _InputIterator, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+__move_backward(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
+{
+    while (__first != __last)
+        *--__result = _VSTD::move(*--__last);
+    return __result;
+}
+
+template <class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_same<typename remove_const<_Tp>::type, _Up>::value &&
+    is_trivially_copy_assignable<_Up>::value,
+    _Up*
+>::type
+__move_backward(_Tp* __first, _Tp* __last, _Up* __result)
+{
+    const size_t __n = static_cast<size_t>(__last - __first);
+    if (__n > 0)
+    {
+        __result -= __n;
+        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
+    }
+    return __result;
+}
+
+template <class _BidirectionalIterator1, class _BidirectionalIterator2>
+inline _LIBCPP_INLINE_VISIBILITY
+_BidirectionalIterator2
+move_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
+              _BidirectionalIterator2 __result)
+{
+    return _VSTD::__move_backward(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
+}
+
+// iter_swap
+
+// moved to <type_traits> for better swap / noexcept support
+
+// transform
+
+template <class _InputIterator, class _OutputIterator, class _UnaryOperation>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+transform(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _UnaryOperation __op)
+{
+    for (; __first != __last; ++__first, (void) ++__result)
+        *__result = __op(*__first);
+    return __result;
+}
+
+template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _BinaryOperation>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+transform(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2,
+          _OutputIterator __result, _BinaryOperation __binary_op)
+{
+    for (; __first1 != __last1; ++__first1, (void) ++__first2, ++__result)
+        *__result = __binary_op(*__first1, *__first2);
+    return __result;
+}
+
+// replace
+
+template <class _ForwardIterator, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+replace(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __old_value, const _Tp& __new_value)
+{
+    for (; __first != __last; ++__first)
+        if (*__first == __old_value)
+            *__first = __new_value;
+}
+
+// replace_if
+
+template <class _ForwardIterator, class _Predicate, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+replace_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, const _Tp& __new_value)
+{
+    for (; __first != __last; ++__first)
+        if (__pred(*__first))
+            *__first = __new_value;
+}
+
+// replace_copy
+
+template <class _InputIterator, class _OutputIterator, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+replace_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
+             const _Tp& __old_value, const _Tp& __new_value)
+{
+    for (; __first != __last; ++__first, (void) ++__result)
+        if (*__first == __old_value)
+            *__result = __new_value;
+        else
+            *__result = *__first;
+    return __result;
+}
+
+// replace_copy_if
+
+template <class _InputIterator, class _OutputIterator, class _Predicate, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+replace_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
+                _Predicate __pred, const _Tp& __new_value)
+{
+    for (; __first != __last; ++__first, (void) ++__result)
+        if (__pred(*__first))
+            *__result = __new_value;
+        else
+            *__result = *__first;
+    return __result;
+}
+
+// fill_n
+
+template <class _OutputIterator, class _Size, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+__fill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
+{
+    for (; __n > 0; ++__first, (void) --__n)
+        *__first = __value_;
+    return __first;
+}
+
+template <class _Tp, class _Size, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && sizeof(_Tp) == 1 &&
+    !is_same<_Tp, bool>::value &&
+    is_integral<_Up>::value && sizeof(_Up) == 1,
+    _Tp*
+>::type
+__fill_n(_Tp* __first, _Size __n,_Up __value_)
+{
+    if (__n > 0)
+        _VSTD::memset(__first, (unsigned char)__value_, (size_t)(__n));
+    return __first + __n;
+}
+
+template <class _OutputIterator, class _Size, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+fill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
+{
+   return _VSTD::__fill_n(__first, __convert_to_integral(__n), __value_);
+}
+
+// fill
+
+template <class _ForwardIterator, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, forward_iterator_tag)
+{
+    for (; __first != __last; ++__first)
+        *__first = __value_;
+}
+
+template <class _RandomAccessIterator, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__fill(_RandomAccessIterator __first, _RandomAccessIterator __last, const _Tp& __value_, random_access_iterator_tag)
+{
+    _VSTD::fill_n(__first, __last - __first, __value_);
+}
+
+template <class _ForwardIterator, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
+{
+    _VSTD::__fill(__first, __last, __value_, typename iterator_traits<_ForwardIterator>::iterator_category());
+}
+
+// generate
+
+template <class _ForwardIterator, class _Generator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+generate(_ForwardIterator __first, _ForwardIterator __last, _Generator __gen)
+{
+    for (; __first != __last; ++__first)
+        *__first = __gen();
+}
+
+// generate_n
+
+template <class _OutputIterator, class _Size, class _Generator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+generate_n(_OutputIterator __first, _Size __orig_n, _Generator __gen)
+{
+    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
+    _IntegralSize __n = __orig_n;
+    for (; __n > 0; ++__first, (void) --__n)
+        *__first = __gen();
+    return __first;
+}
+
+// remove
+
+template <class _ForwardIterator, class _Tp>
+_ForwardIterator
+remove(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
+{
+    __first = _VSTD::find(__first, __last, __value_);
+    if (__first != __last)
+    {
+        _ForwardIterator __i = __first;
+        while (++__i != __last)
+        {
+            if (!(*__i == __value_))
+            {
+                *__first = _VSTD::move(*__i);
+                ++__first;
+            }
+        }
+    }
+    return __first;
+}
+
+// remove_if
+
+template <class _ForwardIterator, class _Predicate>
+_ForwardIterator
+remove_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
+{
+    __first = _VSTD::find_if<_ForwardIterator, typename add_lvalue_reference<_Predicate>::type>
+                           (__first, __last, __pred);
+    if (__first != __last)
+    {
+        _ForwardIterator __i = __first;
+        while (++__i != __last)
+        {
+            if (!__pred(*__i))
+            {
+                *__first = _VSTD::move(*__i);
+                ++__first;
+            }
+        }
+    }
+    return __first;
+}
+
+// remove_copy
+
+template <class _InputIterator, class _OutputIterator, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+remove_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, const _Tp& __value_)
+{
+    for (; __first != __last; ++__first)
+    {
+        if (!(*__first == __value_))
+        {
+            *__result = *__first;
+            ++__result;
+        }
+    }
+    return __result;
+}
+
+// remove_copy_if
+
+template <class _InputIterator, class _OutputIterator, class _Predicate>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+remove_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _Predicate __pred)
+{
+    for (; __first != __last; ++__first)
+    {
+        if (!__pred(*__first))
+        {
+            *__result = *__first;
+            ++__result;
+        }
+    }
+    return __result;
+}
+
+// unique
+
+template <class _ForwardIterator, class _BinaryPredicate>
+_ForwardIterator
+unique(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred)
+{
+    __first = _VSTD::adjacent_find<_ForwardIterator, typename add_lvalue_reference<_BinaryPredicate>::type>
+                                 (__first, __last, __pred);
+    if (__first != __last)
+    {
+        // ...  a  a  ?  ...
+        //      f     i
+        _ForwardIterator __i = __first;
+        for (++__i; ++__i != __last;)
+            if (!__pred(*__first, *__i))
+                *++__first = _VSTD::move(*__i);
+        ++__first;
+    }
+    return __first;
+}
+
+template <class _ForwardIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator
+unique(_ForwardIterator __first, _ForwardIterator __last)
+{
+    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
+    return _VSTD::unique(__first, __last, __equal_to<__v>());
+}
+
+// unique_copy
+
+template <class _BinaryPredicate, class _InputIterator, class _OutputIterator>
+_OutputIterator
+__unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
+              input_iterator_tag, output_iterator_tag)
+{
+    if (__first != __last)
+    {
+        typename iterator_traits<_InputIterator>::value_type __t(*__first);
+        *__result = __t;
+        ++__result;
+        while (++__first != __last)
+        {
+            if (!__pred(__t, *__first))
+            {
+                __t = *__first;
+                *__result = __t;
+                ++__result;
+            }
+        }
+    }
+    return __result;
+}
+
+template <class _BinaryPredicate, class _ForwardIterator, class _OutputIterator>
+_OutputIterator
+__unique_copy(_ForwardIterator __first, _ForwardIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
+              forward_iterator_tag, output_iterator_tag)
+{
+    if (__first != __last)
+    {
+        _ForwardIterator __i = __first;
+        *__result = *__i;
+        ++__result;
+        while (++__first != __last)
+        {
+            if (!__pred(*__i, *__first))
+            {
+                *__result = *__first;
+                ++__result;
+                __i = __first;
+            }
+        }
+    }
+    return __result;
+}
+
+template <class _BinaryPredicate, class _InputIterator, class _ForwardIterator>
+_ForwardIterator
+__unique_copy(_InputIterator __first, _InputIterator __last, _ForwardIterator __result, _BinaryPredicate __pred,
+              input_iterator_tag, forward_iterator_tag)
+{
+    if (__first != __last)
+    {
+        *__result = *__first;
+        while (++__first != __last)
+            if (!__pred(*__result, *__first))
+                *++__result = *__first;
+        ++__result;
+    }
+    return __result;
+}
+
+template <class _InputIterator, class _OutputIterator, class _BinaryPredicate>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred)
+{
+    return _VSTD::__unique_copy<typename add_lvalue_reference<_BinaryPredicate>::type>
+                              (__first, __last, __result, __pred,
+                               typename iterator_traits<_InputIterator>::iterator_category(),
+                               typename iterator_traits<_OutputIterator>::iterator_category());
+}
+
+template <class _InputIterator, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
+{
+    typedef typename iterator_traits<_InputIterator>::value_type __v;
+    return _VSTD::unique_copy(__first, __last, __result, __equal_to<__v>());
+}
+
+// reverse
+
+template <class _BidirectionalIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__reverse(_BidirectionalIterator __first, _BidirectionalIterator __last, bidirectional_iterator_tag)
+{
+    while (__first != __last)
+    {
+        if (__first == --__last)
+            break;
+        swap(*__first, *__last);
+        ++__first;
+    }
+}
+
+template <class _RandomAccessIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__reverse(_RandomAccessIterator __first, _RandomAccessIterator __last, random_access_iterator_tag)
+{
+    if (__first != __last)
+        for (; __first < --__last; ++__first)
+            swap(*__first, *__last);
+}
+
+template <class _BidirectionalIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+reverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
+{
+    _VSTD::__reverse(__first, __last, typename iterator_traits<_BidirectionalIterator>::iterator_category());
+}
+
+// reverse_copy
+
+template <class _BidirectionalIterator, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+reverse_copy(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
+{
+    for (; __first != __last; ++__result)
+        *__result = *--__last;
+    return __result;
+}
+
+// rotate
+
+template <class _ForwardIterator>
+_ForwardIterator
+__rotate_left(_ForwardIterator __first, _ForwardIterator __last)
+{
+    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
+    value_type __tmp = _VSTD::move(*__first);
+    _ForwardIterator __lm1 = _VSTD::move(_VSTD::next(__first), __last, __first);
+    *__lm1 = _VSTD::move(__tmp);
+    return __lm1;
+}
+
+template <class _BidirectionalIterator>
+_BidirectionalIterator
+__rotate_right(_BidirectionalIterator __first, _BidirectionalIterator __last)
+{
+    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
+    _BidirectionalIterator __lm1 = _VSTD::prev(__last);
+    value_type __tmp = _VSTD::move(*__lm1);
+    _BidirectionalIterator __fp1 = _VSTD::move_backward(__first, __lm1, __last);
+    *__first = _VSTD::move(__tmp);
+    return __fp1;
+}
+
+template <class _ForwardIterator>
+_ForwardIterator
+__rotate_forward(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
+{
+    _ForwardIterator __i = __middle;
+    while (true)
+    {
+        swap(*__first, *__i);
+        ++__first;
+        if (++__i == __last)
+            break;
+        if (__first == __middle)
+            __middle = __i;
+    }
+    _ForwardIterator __r = __first;
+    if (__first != __middle)
+    {
+        __i = __middle;
+        while (true)
+        {
+            swap(*__first, *__i);
+            ++__first;
+            if (++__i == __last)
+            {
+                if (__first == __middle)
+                    break;
+                __i = __middle;
+            }
+            else if (__first == __middle)
+                __middle = __i;
+        }
+    }
+    return __r;
+}
+
+template<typename _Integral>
+inline _LIBCPP_INLINE_VISIBILITY
+_Integral
+__gcd(_Integral __x, _Integral __y)
+{
+    do
+    {
+        _Integral __t = __x % __y;
+        __x = __y;
+        __y = __t;
+    } while (__y);
+    return __x;
+}
+
+template<typename _RandomAccessIterator>
+_RandomAccessIterator
+__rotate_gcd(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
+{
+    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
+    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
+
+    const difference_type __m1 = __middle - __first;
+    const difference_type __m2 = __last - __middle;
+    if (__m1 == __m2)
+    {
+        _VSTD::swap_ranges(__first, __middle, __middle);
+        return __middle;
+    }
+    const difference_type __g = _VSTD::__gcd(__m1, __m2);
+    for (_RandomAccessIterator __p = __first + __g; __p != __first;)
+    {
+        value_type __t(_VSTD::move(*--__p));
+        _RandomAccessIterator __p1 = __p;
+        _RandomAccessIterator __p2 = __p1 + __m1;
+        do
+        {
+            *__p1 = _VSTD::move(*__p2);
+            __p1 = __p2;
+            const difference_type __d = __last - __p2;
+            if (__m1 < __d)
+                __p2 += __m1;
+            else
+                __p2 = __first + (__m1 - __d);
+        } while (__p2 != __p);
+        *__p1 = _VSTD::move(__t);
+    }
+    return __first + __m2;
+}
+
+template <class _ForwardIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator
+__rotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last,
+         _VSTD::forward_iterator_tag)
+{
+    typedef typename _VSTD::iterator_traits<_ForwardIterator>::value_type value_type;
+    if (_VSTD::is_trivially_move_assignable<value_type>::value)
+    {
+        if (_VSTD::next(__first) == __middle)
+            return _VSTD::__rotate_left(__first, __last);
+    }
+    return _VSTD::__rotate_forward(__first, __middle, __last);
+}
+
+template <class _BidirectionalIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_BidirectionalIterator
+__rotate(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
+         _VSTD::bidirectional_iterator_tag)
+{
+    typedef typename _VSTD::iterator_traits<_BidirectionalIterator>::value_type value_type;
+    if (_VSTD::is_trivially_move_assignable<value_type>::value)
+    {
+        if (_VSTD::next(__first) == __middle)
+            return _VSTD::__rotate_left(__first, __last);
+        if (_VSTD::next(__middle) == __last)
+            return _VSTD::__rotate_right(__first, __last);
+    }
+    return _VSTD::__rotate_forward(__first, __middle, __last);
+}
+
+template <class _RandomAccessIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_RandomAccessIterator
+__rotate(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
+         _VSTD::random_access_iterator_tag)
+{
+    typedef typename _VSTD::iterator_traits<_RandomAccessIterator>::value_type value_type;
+    if (_VSTD::is_trivially_move_assignable<value_type>::value)
+    {
+        if (_VSTD::next(__first) == __middle)
+            return _VSTD::__rotate_left(__first, __last);
+        if (_VSTD::next(__middle) == __last)
+            return _VSTD::__rotate_right(__first, __last);
+        return _VSTD::__rotate_gcd(__first, __middle, __last);
+    }
+    return _VSTD::__rotate_forward(__first, __middle, __last);
+}
+
+template <class _ForwardIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator
+rotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
+{
+    if (__first == __middle)
+        return __last;
+    if (__middle == __last)
+        return __first;
+    return _VSTD::__rotate(__first, __middle, __last,
+                           typename _VSTD::iterator_traits<_ForwardIterator>::iterator_category());
+}
+
+// rotate_copy
+
+template <class _ForwardIterator, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+rotate_copy(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last, _OutputIterator __result)
+{
+    return _VSTD::copy(__first, __middle, _VSTD::copy(__middle, __last, __result));
+}
+
+// min_element
+
+template <class _ForwardIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_ForwardIterator
+min_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
+{
+    if (__first != __last)
+    {
+        _ForwardIterator __i = __first;
+        while (++__i != __last)
+            if (__comp(*__i, *__first))
+                __first = __i;
+    }
+    return __first;
+}
+
+template <class _ForwardIterator>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_ForwardIterator
+min_element(_ForwardIterator __first, _ForwardIterator __last)
+{
+    return _VSTD::min_element(__first, __last,
+              __less<typename iterator_traits<_ForwardIterator>::value_type>());
+}
+
+// min
+
+template <class _Tp, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const _Tp&
+min(const _Tp& __a, const _Tp& __b, _Compare __comp)
+{
+    return __comp(__b, __a) ? __b : __a;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const _Tp&
+min(const _Tp& __a, const _Tp& __b)
+{
+    return _VSTD::min(__a, __b, __less<_Tp>());
+}
+
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+template<class _Tp, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_Tp
+min(initializer_list<_Tp> __t, _Compare __comp)
+{
+    return *_VSTD::min_element(__t.begin(), __t.end(), __comp);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_Tp
+min(initializer_list<_Tp> __t)
+{
+    return *_VSTD::min_element(__t.begin(), __t.end(), __less<_Tp>());
+}
+
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+// max_element
+
+template <class _ForwardIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_ForwardIterator
+max_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
+{
+    if (__first != __last)
+    {
+        _ForwardIterator __i = __first;
+        while (++__i != __last)
+            if (__comp(*__first, *__i))
+                __first = __i;
+    }
+    return __first;
+}
+
+
+template <class _ForwardIterator>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_ForwardIterator
+max_element(_ForwardIterator __first, _ForwardIterator __last)
+{
+    return _VSTD::max_element(__first, __last,
+              __less<typename iterator_traits<_ForwardIterator>::value_type>());
+}
+
+// max
+
+template <class _Tp, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const _Tp&
+max(const _Tp& __a, const _Tp& __b, _Compare __comp)
+{
+    return __comp(__a, __b) ? __b : __a;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const _Tp&
+max(const _Tp& __a, const _Tp& __b)
+{
+    return _VSTD::max(__a, __b, __less<_Tp>());
+}
+
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+template<class _Tp, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_Tp
+max(initializer_list<_Tp> __t, _Compare __comp)
+{
+    return *_VSTD::max_element(__t.begin(), __t.end(), __comp);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_Tp
+max(initializer_list<_Tp> __t)
+{
+    return *_VSTD::max_element(__t.begin(), __t.end(), __less<_Tp>());
+}
+
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+// minmax_element
+
+template <class _ForwardIterator, class _Compare>
+_LIBCPP_CONSTEXPR_AFTER_CXX11
+std::pair<_ForwardIterator, _ForwardIterator>
+minmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
+{
+  std::pair<_ForwardIterator, _ForwardIterator> __result(__first, __first);
+  if (__first != __last)
+  {
+      if (++__first != __last)
+      {
+          if (__comp(*__first, *__result.first))
+              __result.first = __first;
+          else
+              __result.second = __first;
+          while (++__first != __last)
+          {
+              _ForwardIterator __i = __first;
+              if (++__first == __last)
+              {
+                  if (__comp(*__i, *__result.first))
+                      __result.first = __i;
+                  else if (!__comp(*__i, *__result.second))
+                      __result.second = __i;
+                  break;
+              }
+              else
+              {
+                  if (__comp(*__first, *__i))
+                  {
+                      if (__comp(*__first, *__result.first))
+                          __result.first = __first;
+                      if (!__comp(*__i, *__result.second))
+                          __result.second = __i;
+                  }
+                  else
+                  {
+                      if (__comp(*__i, *__result.first))
+                          __result.first = __i;
+                      if (!__comp(*__first, *__result.second))
+                          __result.second = __first;
+                  }
+              }
+          }
+      }
+  }
+  return __result;
+}
+
+template <class _ForwardIterator>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+std::pair<_ForwardIterator, _ForwardIterator>
+minmax_element(_ForwardIterator __first, _ForwardIterator __last)
+{
+    return _VSTD::minmax_element(__first, __last,
+              __less<typename iterator_traits<_ForwardIterator>::value_type>());
+}
+
+// minmax
+
+template<class _Tp, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<const _Tp&, const _Tp&>
+minmax(const _Tp& __a, const _Tp& __b, _Compare __comp)
+{
+    return __comp(__b, __a) ? pair<const _Tp&, const _Tp&>(__b, __a) :
+                              pair<const _Tp&, const _Tp&>(__a, __b);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<const _Tp&, const _Tp&>
+minmax(const _Tp& __a, const _Tp& __b)
+{
+    return _VSTD::minmax(__a, __b, __less<_Tp>());
+}
+
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+template<class _Tp, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<_Tp, _Tp>
+minmax(initializer_list<_Tp> __t, _Compare __comp)
+{
+    typedef typename initializer_list<_Tp>::const_iterator _Iter;
+    _Iter __first = __t.begin();
+    _Iter __last  = __t.end();
+    std::pair<_Tp, _Tp> __result(*__first, *__first);
+
+    ++__first;
+    if (__t.size() % 2 == 0)
+    {
+        if (__comp(*__first,  __result.first))
+            __result.first  = *__first;
+        else
+            __result.second = *__first;
+        ++__first;
+    }
+    
+    while (__first != __last)
+    {
+        _Tp __prev = *__first++;
+        if (__comp(*__first, __prev)) {
+            if ( __comp(*__first, __result.first)) __result.first  = *__first;
+            if (!__comp(__prev, __result.second))  __result.second = __prev;
+            }
+        else {
+            if ( __comp(__prev, __result.first))    __result.first  = __prev;
+            if (!__comp(*__first, __result.second)) __result.second = *__first;
+            }
+                
+        __first++;
+    }
+    return __result;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+pair<_Tp, _Tp>
+minmax(initializer_list<_Tp> __t)
+{
+    return _VSTD::minmax(__t, __less<_Tp>());
+}
+
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+// random_shuffle
+
+// __independent_bits_engine
+
+template <unsigned long long _Xp, size_t _Rp>
+struct __log2_imp
+{
+    static const size_t value = _Xp & ((unsigned long long)(1) << _Rp) ? _Rp
+                                           : __log2_imp<_Xp, _Rp - 1>::value;
+};
+
+template <unsigned long long _Xp>
+struct __log2_imp<_Xp, 0>
+{
+    static const size_t value = 0;
+};
+
+template <size_t _Rp>
+struct __log2_imp<0, _Rp>
+{
+    static const size_t value = _Rp + 1;
+};
+
+template <class _UI, _UI _Xp>
+struct __log2
+{
+    static const size_t value = __log2_imp<_Xp,
+                                         sizeof(_UI) * __CHAR_BIT__ - 1>::value;
+};
+
+template<class _Engine, class _UIntType>
+class __independent_bits_engine
+{
+public:
+    // types
+    typedef _UIntType result_type;
+
+private:
+    typedef typename _Engine::result_type _Engine_result_type;
+    typedef typename conditional
+        <
+            sizeof(_Engine_result_type) <= sizeof(result_type),
+                result_type,
+                _Engine_result_type
+        >::type _Working_result_type;
+
+    _Engine& __e_;
+    size_t __w_;
+    size_t __w0_;
+    size_t __n_;
+    size_t __n0_;
+    _Working_result_type __y0_;
+    _Working_result_type __y1_;
+    _Engine_result_type __mask0_;
+    _Engine_result_type __mask1_;
+
+#ifdef _LIBCPP_HAS_NO_CONSTEXPR
+    static const _Working_result_type _Rp = _Engine::_Max - _Engine::_Min
+                                          + _Working_result_type(1);
+#else
+    static _LIBCPP_CONSTEXPR const _Working_result_type _Rp = _Engine::max() - _Engine::min()
+                                                      + _Working_result_type(1);
+#endif
+    static _LIBCPP_CONSTEXPR const size_t __m = __log2<_Working_result_type, _Rp>::value;
+    static _LIBCPP_CONSTEXPR const size_t _WDt = numeric_limits<_Working_result_type>::digits;
+    static _LIBCPP_CONSTEXPR const size_t _EDt = numeric_limits<_Engine_result_type>::digits;
+
+public:
+    // constructors and seeding functions
+    __independent_bits_engine(_Engine& __e, size_t __w);
+
+    // generating functions
+    result_type operator()() {return __eval(integral_constant<bool, _Rp != 0>());}
+
+private:
+    result_type __eval(false_type);
+    result_type __eval(true_type);
+};
+
+template<class _Engine, class _UIntType>
+__independent_bits_engine<_Engine, _UIntType>
+    ::__independent_bits_engine(_Engine& __e, size_t __w)
+        : __e_(__e),
+          __w_(__w)
+{
+    __n_ = __w_ / __m + (__w_ % __m != 0);
+    __w0_ = __w_ / __n_;
+    if (_Rp == 0)
+        __y0_ = _Rp;
+    else if (__w0_ < _WDt)
+        __y0_ = (_Rp >> __w0_) << __w0_;
+    else
+        __y0_ = 0;
+    if (_Rp - __y0_ > __y0_ / __n_)
+    {
+        ++__n_;
+        __w0_ = __w_ / __n_;
+        if (__w0_ < _WDt)
+            __y0_ = (_Rp >> __w0_) << __w0_;
+        else
+            __y0_ = 0;
+    }
+    __n0_ = __n_ - __w_ % __n_;
+    if (__w0_ < _WDt - 1)
+        __y1_ = (_Rp >> (__w0_ + 1)) << (__w0_ + 1);
+    else
+        __y1_ = 0;
+    __mask0_ = __w0_ > 0 ? _Engine_result_type(~0) >> (_EDt - __w0_) :
+                          _Engine_result_type(0);
+    __mask1_ = __w0_ < _EDt - 1 ?
+                               _Engine_result_type(~0) >> (_EDt - (__w0_ + 1)) :
+                               _Engine_result_type(~0);
+}
+
+template<class _Engine, class _UIntType>
+inline
+_UIntType
+__independent_bits_engine<_Engine, _UIntType>::__eval(false_type)
+{
+    return static_cast<result_type>(__e_() & __mask0_);
+}
+
+template<class _Engine, class _UIntType>
+_UIntType
+__independent_bits_engine<_Engine, _UIntType>::__eval(true_type)
+{
+    result_type _Sp = 0;
+    for (size_t __k = 0; __k < __n0_; ++__k)
+    {
+        _Engine_result_type __u;
+        do
+        {
+            __u = __e_() - _Engine::min();
+        } while (__u >= __y0_);
+        if (__w0_ < _WDt)
+            _Sp <<= __w0_;
+        else
+            _Sp = 0;
+        _Sp += __u & __mask0_;
+    }
+    for (size_t __k = __n0_; __k < __n_; ++__k)
+    {
+        _Engine_result_type __u;
+        do
+        {
+            __u = __e_() - _Engine::min();
+        } while (__u >= __y1_);
+        if (__w0_ < _WDt - 1)
+            _Sp <<= __w0_ + 1;
+        else
+            _Sp = 0;
+        _Sp += __u & __mask1_;
+    }
+    return _Sp;
+}
+
+// uniform_int_distribution
+
+template<class _IntType = int>
+class uniform_int_distribution
+{
+public:
+    // types
+    typedef _IntType result_type;
+
+    class param_type
+    {
+        result_type __a_;
+        result_type __b_;
+    public:
+        typedef uniform_int_distribution distribution_type;
+
+        explicit param_type(result_type __a = 0,
+                            result_type __b = numeric_limits<result_type>::max())
+            : __a_(__a), __b_(__b) {}
+
+        result_type a() const {return __a_;}
+        result_type b() const {return __b_;}
+
+        friend bool operator==(const param_type& __x, const param_type& __y)
+            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
+        friend bool operator!=(const param_type& __x, const param_type& __y)
+            {return !(__x == __y);}
+    };
+
+private:
+    param_type __p_;
+
+public:
+    // constructors and reset functions
+    explicit uniform_int_distribution(result_type __a = 0,
+                                      result_type __b = numeric_limits<result_type>::max())
+        : __p_(param_type(__a, __b)) {}
+    explicit uniform_int_distribution(const param_type& __p) : __p_(__p) {}
+    void reset() {}
+
+    // generating functions
+    template<class _URNG> result_type operator()(_URNG& __g)
+        {return (*this)(__g, __p_);}
+    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
+
+    // property functions
+    result_type a() const {return __p_.a();}
+    result_type b() const {return __p_.b();}
+
+    param_type param() const {return __p_;}
+    void param(const param_type& __p) {__p_ = __p;}
+
+    result_type min() const {return a();}
+    result_type max() const {return b();}
+
+    friend bool operator==(const uniform_int_distribution& __x,
+                           const uniform_int_distribution& __y)
+        {return __x.__p_ == __y.__p_;}
+    friend bool operator!=(const uniform_int_distribution& __x,
+                           const uniform_int_distribution& __y)
+            {return !(__x == __y);}
+};
+
+template<class _IntType>
+template<class _URNG>
+typename uniform_int_distribution<_IntType>::result_type
+uniform_int_distribution<_IntType>::operator()(_URNG& __g, const param_type& __p)
+{
+    typedef typename conditional<sizeof(result_type) <= sizeof(uint32_t),
+                                            uint32_t, uint64_t>::type _UIntType;
+    const _UIntType _Rp = __p.b() - __p.a() + _UIntType(1);
+    if (_Rp == 1)
+        return __p.a();
+    const size_t _Dt = numeric_limits<_UIntType>::digits;
+    typedef __independent_bits_engine<_URNG, _UIntType> _Eng;
+    if (_Rp == 0)
+        return static_cast<result_type>(_Eng(__g, _Dt)());
+    size_t __w = _Dt - __clz(_Rp) - 1;
+    if ((_Rp & (std::numeric_limits<_UIntType>::max() >> (_Dt - __w))) != 0)
+        ++__w;
+    _Eng __e(__g, __w);
+    _UIntType __u;
+    do
+    {
+        __u = __e();
+    } while (__u >= _Rp);
+    return static_cast<result_type>(__u + __p.a());
+}
+
+class _LIBCPP_TYPE_VIS __rs_default;
+
+_LIBCPP_FUNC_VIS __rs_default __rs_get();
+
+class _LIBCPP_TYPE_VIS __rs_default
+{
+    static unsigned __c_;
+
+    __rs_default();
+public:
+    typedef uint_fast32_t result_type;
+
+    static const result_type _Min = 0;
+    static const result_type _Max = 0xFFFFFFFF;
+
+    __rs_default(const __rs_default&);
+    ~__rs_default();
+
+    result_type operator()();
+
+    static _LIBCPP_CONSTEXPR result_type min() {return _Min;}
+    static _LIBCPP_CONSTEXPR result_type max() {return _Max;}
+
+    friend _LIBCPP_FUNC_VIS __rs_default __rs_get();
+};
+
+_LIBCPP_FUNC_VIS __rs_default __rs_get();
+
+template <class _RandomAccessIterator>
+void
+random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last)
+{
+    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
+    typedef uniform_int_distribution<ptrdiff_t> _Dp;
+    typedef typename _Dp::param_type _Pp;
+    difference_type __d = __last - __first;
+    if (__d > 1)
+    {
+        _Dp __uid;
+        __rs_default __g = __rs_get();
+        for (--__last, --__d; __first < __last; ++__first, --__d)
+        {
+            difference_type __i = __uid(__g, _Pp(0, __d));
+            if (__i != difference_type(0))
+                swap(*__first, *(__first + __i));
+        }
+    }
+}
+
+template <class _RandomAccessIterator, class _RandomNumberGenerator>
+void
+random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+               _RandomNumberGenerator&& __rand)
+#else
+               _RandomNumberGenerator& __rand)
+#endif
+{
+    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
+    difference_type __d = __last - __first;
+    if (__d > 1)
+    {
+        for (--__last; __first < __last; ++__first, --__d)
+        {
+            difference_type __i = __rand(__d);
+            swap(*__first, *(__first + __i));
+        }
+    }
+}
+
+template<class _RandomAccessIterator, class _UniformRandomNumberGenerator>
+    void shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+                 _UniformRandomNumberGenerator&& __g)
+#else
+                 _UniformRandomNumberGenerator& __g)
+#endif
+{
+    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
+    typedef uniform_int_distribution<ptrdiff_t> _Dp;
+    typedef typename _Dp::param_type _Pp;
+    difference_type __d = __last - __first;
+    if (__d > 1)
+    {
+        _Dp __uid;
+        for (--__last, --__d; __first < __last; ++__first, --__d)
+        {
+            difference_type __i = __uid(__g, _Pp(0, __d));
+            if (__i != difference_type(0))
+                swap(*__first, *(__first + __i));
+        }
+    }
+}
+
+template <class _InputIterator, class _Predicate>
+bool
+is_partitioned(_InputIterator __first, _InputIterator __last, _Predicate __pred)
+{
+    for (; __first != __last; ++__first)
+        if (!__pred(*__first))
+            break;
+    if ( __first == __last )
+        return true;
+    ++__first;
+    for (; __first != __last; ++__first)
+        if (__pred(*__first))
+            return false;
+    return true;
+}
+
+// partition
+
+template <class _Predicate, class _ForwardIterator>
+_ForwardIterator
+__partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, forward_iterator_tag)
+{
+    while (true)
+    {
+        if (__first == __last)
+            return __first;
+        if (!__pred(*__first))
+            break;
+        ++__first;
+    }
+    for (_ForwardIterator __p = __first; ++__p != __last;)
+    {
+        if (__pred(*__p))
+        {
+            swap(*__first, *__p);
+            ++__first;
+        }
+    }
+    return __first;
+}
+
+template <class _Predicate, class _BidirectionalIterator>
+_BidirectionalIterator
+__partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
+            bidirectional_iterator_tag)
+{
+    while (true)
+    {
+        while (true)
+        {
+            if (__first == __last)
+                return __first;
+            if (!__pred(*__first))
+                break;
+            ++__first;
+        }
+        do
+        {
+            if (__first == --__last)
+                return __first;
+        } while (!__pred(*__last));
+        swap(*__first, *__last);
+        ++__first;
+    }
+}
+
+template <class _ForwardIterator, class _Predicate>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator
+partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
+{
+    return _VSTD::__partition<typename add_lvalue_reference<_Predicate>::type>
+                            (__first, __last, __pred, typename iterator_traits<_ForwardIterator>::iterator_category());
+}
+
+// partition_copy
+
+template <class _InputIterator, class _OutputIterator1,
+          class _OutputIterator2, class _Predicate>
+pair<_OutputIterator1, _OutputIterator2>
+partition_copy(_InputIterator __first, _InputIterator __last,
+               _OutputIterator1 __out_true, _OutputIterator2 __out_false,
+               _Predicate __pred)
+{
+    for (; __first != __last; ++__first)
+    {
+        if (__pred(*__first))
+        {
+            *__out_true = *__first;
+            ++__out_true;
+        }
+        else
+        {
+            *__out_false = *__first;
+            ++__out_false;
+        }
+    }
+    return pair<_OutputIterator1, _OutputIterator2>(__out_true, __out_false);
+}
+
+// partition_point
+
+template<class _ForwardIterator, class _Predicate>
+_ForwardIterator
+partition_point(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
+{
+    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
+    difference_type __len = _VSTD::distance(__first, __last);
+    while (__len != 0)
+    {
+        difference_type __l2 = __len / 2;
+        _ForwardIterator __m = __first;
+        _VSTD::advance(__m, __l2);
+        if (__pred(*__m))
+        {
+            __first = ++__m;
+            __len -= __l2 + 1;
+        }
+        else
+            __len = __l2;
+    }
+    return __first;
+}
+
+// stable_partition
+
+template <class _Predicate, class _ForwardIterator, class _Distance, class _Pair>
+_ForwardIterator
+__stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred,
+                   _Distance __len, _Pair __p, forward_iterator_tag __fit)
+{
+    // *__first is known to be false
+    // __len >= 1
+    if (__len == 1)
+        return __first;
+    if (__len == 2)
+    {
+        _ForwardIterator __m = __first;
+        if (__pred(*++__m))
+        {
+            swap(*__first, *__m);
+            return __m;
+        }
+        return __first;
+    }
+    if (__len <= __p.second)
+    {   // The buffer is big enough to use
+        typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
+        __destruct_n __d(0);
+        unique_ptr<value_type, __destruct_n&> __h(__p.first, __d);
+        // Move the falses into the temporary buffer, and the trues to the front of the line
+        // Update __first to always point to the end of the trues
+        value_type* __t = __p.first;
+        ::new(__t) value_type(_VSTD::move(*__first));
+        __d.__incr((value_type*)0);
+        ++__t;
+        _ForwardIterator __i = __first;
+        while (++__i != __last)
+        {
+            if (__pred(*__i))
+            {
+                *__first = _VSTD::move(*__i);
+                ++__first;
+            }
+            else
+            {
+                ::new(__t) value_type(_VSTD::move(*__i));
+                __d.__incr((value_type*)0);
+                ++__t;
+            }
+        }
+        // All trues now at start of range, all falses in buffer
+        // Move falses back into range, but don't mess up __first which points to first false
+        __i = __first;
+        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, ++__i)
+            *__i = _VSTD::move(*__t2);
+        // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
+        return __first;
+    }
+    // Else not enough buffer, do in place
+    // __len >= 3
+    _ForwardIterator __m = __first;
+    _Distance __len2 = __len / 2;  // __len2 >= 2
+    _VSTD::advance(__m, __len2);
+    // recurse on [__first, __m), *__first know to be false
+    // F?????????????????
+    // f       m         l
+    typedef typename add_lvalue_reference<_Predicate>::type _PredRef;
+    _ForwardIterator __first_false = __stable_partition<_PredRef>(__first, __m, __pred, __len2, __p, __fit);
+    // TTTFFFFF??????????
+    // f  ff   m         l
+    // recurse on [__m, __last], except increase __m until *(__m) is false, *__last know to be true
+    _ForwardIterator __m1 = __m;
+    _ForwardIterator __second_false = __last;
+    _Distance __len_half = __len - __len2;
+    while (__pred(*__m1))
+    {
+        if (++__m1 == __last)
+            goto __second_half_done;
+        --__len_half;
+    }
+    // TTTFFFFFTTTF??????
+    // f  ff   m  m1     l
+    __second_false = __stable_partition<_PredRef>(__m1, __last, __pred, __len_half, __p, __fit);
+__second_half_done:
+    // TTTFFFFFTTTTTFFFFF
+    // f  ff   m    sf   l
+    return _VSTD::rotate(__first_false, __m, __second_false);
+    // TTTTTTTTFFFFFFFFFF
+    //         |
+}
+
+struct __return_temporary_buffer
+{
+    template <class _Tp>
+    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) const {_VSTD::return_temporary_buffer(__p);}
+};
+
+template <class _Predicate, class _ForwardIterator>
+_ForwardIterator
+__stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred,
+                   forward_iterator_tag)
+{
+    const unsigned __alloc_limit = 3;  // might want to make this a function of trivial assignment
+    // Either prove all true and return __first or point to first false
+    while (true)
+    {
+        if (__first == __last)
+            return __first;
+        if (!__pred(*__first))
+            break;
+        ++__first;
+    }
+    // We now have a reduced range [__first, __last)
+    // *__first is known to be false
+    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
+    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
+    difference_type __len = _VSTD::distance(__first, __last);
+    pair<value_type*, ptrdiff_t> __p(0, 0);
+    unique_ptr<value_type, __return_temporary_buffer> __h;
+    if (__len >= __alloc_limit)
+    {
+        __p = _VSTD::get_temporary_buffer<value_type>(__len);
+        __h.reset(__p.first);
+    }
+    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
+                             (__first, __last, __pred, __len, __p, forward_iterator_tag());
+}
+
+template <class _Predicate, class _BidirectionalIterator, class _Distance, class _Pair>
+_BidirectionalIterator
+__stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
+                   _Distance __len, _Pair __p, bidirectional_iterator_tag __bit)
+{
+    // *__first is known to be false
+    // *__last is known to be true
+    // __len >= 2
+    if (__len == 2)
+    {
+        swap(*__first, *__last);
+        return __last;
+    }
+    if (__len == 3)
+    {
+        _BidirectionalIterator __m = __first;
+        if (__pred(*++__m))
+        {
+            swap(*__first, *__m);
+            swap(*__m, *__last);
+            return __last;
+        }
+        swap(*__m, *__last);
+        swap(*__first, *__m);
+        return __m;
+    }
+    if (__len <= __p.second)
+    {   // The buffer is big enough to use
+        typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
+        __destruct_n __d(0);
+        unique_ptr<value_type, __destruct_n&> __h(__p.first, __d);
+        // Move the falses into the temporary buffer, and the trues to the front of the line
+        // Update __first to always point to the end of the trues
+        value_type* __t = __p.first;
+        ::new(__t) value_type(_VSTD::move(*__first));
+        __d.__incr((value_type*)0);
+        ++__t;
+        _BidirectionalIterator __i = __first;
+        while (++__i != __last)
+        {
+            if (__pred(*__i))
+            {
+                *__first = _VSTD::move(*__i);
+                ++__first;
+            }
+            else
+            {
+                ::new(__t) value_type(_VSTD::move(*__i));
+                __d.__incr((value_type*)0);
+                ++__t;
+            }
+        }
+        // move *__last, known to be true
+        *__first = _VSTD::move(*__i);
+        __i = ++__first;
+        // All trues now at start of range, all falses in buffer
+        // Move falses back into range, but don't mess up __first which points to first false
+        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, ++__i)
+            *__i = _VSTD::move(*__t2);
+        // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
+        return __first;
+    }
+    // Else not enough buffer, do in place
+    // __len >= 4
+    _BidirectionalIterator __m = __first;
+    _Distance __len2 = __len / 2;  // __len2 >= 2
+    _VSTD::advance(__m, __len2);
+    // recurse on [__first, __m-1], except reduce __m-1 until *(__m-1) is true, *__first know to be false
+    // F????????????????T
+    // f       m        l
+    _BidirectionalIterator __m1 = __m;
+    _BidirectionalIterator __first_false = __first;
+    _Distance __len_half = __len2;
+    while (!__pred(*--__m1))
+    {
+        if (__m1 == __first)
+            goto __first_half_done;
+        --__len_half;
+    }
+    // F???TFFF?????????T
+    // f   m1  m        l
+    typedef typename add_lvalue_reference<_Predicate>::type _PredRef;
+    __first_false = __stable_partition<_PredRef>(__first, __m1, __pred, __len_half, __p, __bit);
+__first_half_done:
+    // TTTFFFFF?????????T
+    // f  ff   m        l
+    // recurse on [__m, __last], except increase __m until *(__m) is false, *__last know to be true
+    __m1 = __m;
+    _BidirectionalIterator __second_false = __last;
+    ++__second_false;
+    __len_half = __len - __len2;
+    while (__pred(*__m1))
+    {
+        if (++__m1 == __last)
+            goto __second_half_done;
+        --__len_half;
+    }
+    // TTTFFFFFTTTF?????T
+    // f  ff   m  m1    l
+    __second_false = __stable_partition<_PredRef>(__m1, __last, __pred, __len_half, __p, __bit);
+__second_half_done:
+    // TTTFFFFFTTTTTFFFFF
+    // f  ff   m    sf  l
+    return _VSTD::rotate(__first_false, __m, __second_false);
+    // TTTTTTTTFFFFFFFFFF
+    //         |
+}
+
+template <class _Predicate, class _BidirectionalIterator>
+_BidirectionalIterator
+__stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
+                   bidirectional_iterator_tag)
+{
+    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
+    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
+    const difference_type __alloc_limit = 4;  // might want to make this a function of trivial assignment
+    // Either prove all true and return __first or point to first false
+    while (true)
+    {
+        if (__first == __last)
+            return __first;
+        if (!__pred(*__first))
+            break;
+        ++__first;
+    }
+    // __first points to first false, everything prior to __first is already set.
+    // Either prove [__first, __last) is all false and return __first, or point __last to last true
+    do
+    {
+        if (__first == --__last)
+            return __first;
+    } while (!__pred(*__last));
+    // We now have a reduced range [__first, __last]
+    // *__first is known to be false
+    // *__last is known to be true
+    // __len >= 2
+    difference_type __len = _VSTD::distance(__first, __last) + 1;
+    pair<value_type*, ptrdiff_t> __p(0, 0);
+    unique_ptr<value_type, __return_temporary_buffer> __h;
+    if (__len >= __alloc_limit)
+    {
+        __p = _VSTD::get_temporary_buffer<value_type>(__len);
+        __h.reset(__p.first);
+    }
+    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
+                             (__first, __last, __pred, __len, __p, bidirectional_iterator_tag());
+}
+
+template <class _ForwardIterator, class _Predicate>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator
+stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
+{
+    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
+                             (__first, __last, __pred, typename iterator_traits<_ForwardIterator>::iterator_category());
+}
+
+// is_sorted_until
+
+template <class _ForwardIterator, class _Compare>
+_ForwardIterator
+is_sorted_until(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
+{
+    if (__first != __last)
+    {
+        _ForwardIterator __i = __first;
+        while (++__i != __last)
+        {
+            if (__comp(*__i, *__first))
+                return __i;
+            __first = __i;
+        }
+    }
+    return __last;
+}
+
+template<class _ForwardIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator
+is_sorted_until(_ForwardIterator __first, _ForwardIterator __last)
+{
+    return _VSTD::is_sorted_until(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
+}
+
+// is_sorted
+
+template <class _ForwardIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+is_sorted(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
+{
+    return _VSTD::is_sorted_until(__first, __last, __comp) == __last;
+}
+
+template<class _ForwardIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+is_sorted(_ForwardIterator __first, _ForwardIterator __last)
+{
+    return _VSTD::is_sorted(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
+}
+
+// sort
+
+// stable, 2-3 compares, 0-2 swaps
+
+template <class _Compare, class _ForwardIterator>
+unsigned
+__sort3(_ForwardIterator __x, _ForwardIterator __y, _ForwardIterator __z, _Compare __c)
+{
+    unsigned __r = 0;
+    if (!__c(*__y, *__x))          // if x <= y
+    {
+        if (!__c(*__z, *__y))      // if y <= z
+            return __r;            // x <= y && y <= z
+                                   // x <= y && y > z
+        swap(*__y, *__z);          // x <= z && y < z
+        __r = 1;
+        if (__c(*__y, *__x))       // if x > y
+        {
+            swap(*__x, *__y);      // x < y && y <= z
+            __r = 2;
+        }
+        return __r;                // x <= y && y < z
+    }
+    if (__c(*__z, *__y))           // x > y, if y > z
+    {
+        swap(*__x, *__z);          // x < y && y < z
+        __r = 1;
+        return __r;
+    }
+    swap(*__x, *__y);              // x > y && y <= z
+    __r = 1;                       // x < y && x <= z
+    if (__c(*__z, *__y))           // if y > z
+    {
+        swap(*__y, *__z);          // x <= y && y < z
+        __r = 2;
+    }
+    return __r;
+}                                  // x <= y && y <= z
+
+// stable, 3-6 compares, 0-5 swaps
+
+template <class _Compare, class _ForwardIterator>
+unsigned
+__sort4(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
+            _ForwardIterator __x4, _Compare __c)
+{
+    unsigned __r = __sort3<_Compare>(__x1, __x2, __x3, __c);
+    if (__c(*__x4, *__x3))
+    {
+        swap(*__x3, *__x4);
+        ++__r;
+        if (__c(*__x3, *__x2))
+        {
+            swap(*__x2, *__x3);
+            ++__r;
+            if (__c(*__x2, *__x1))
+            {
+                swap(*__x1, *__x2);
+                ++__r;
+            }
+        }
+    }
+    return __r;
+}
+
+// stable, 4-10 compares, 0-9 swaps
+
+template <class _Compare, class _ForwardIterator>
+unsigned
+__sort5(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
+            _ForwardIterator __x4, _ForwardIterator __x5, _Compare __c)
+{
+    unsigned __r = __sort4<_Compare>(__x1, __x2, __x3, __x4, __c);
+    if (__c(*__x5, *__x4))
+    {
+        swap(*__x4, *__x5);
+        ++__r;
+        if (__c(*__x4, *__x3))
+        {
+            swap(*__x3, *__x4);
+            ++__r;
+            if (__c(*__x3, *__x2))
+            {
+                swap(*__x2, *__x3);
+                ++__r;
+                if (__c(*__x2, *__x1))
+                {
+                    swap(*__x1, *__x2);
+                    ++__r;
+                }
+            }
+        }
+    }
+    return __r;
+}
+
+// Assumes size > 0
+template <class _Compare, class _BirdirectionalIterator>
+void
+__selection_sort(_BirdirectionalIterator __first, _BirdirectionalIterator __last, _Compare __comp)
+{
+    _BirdirectionalIterator __lm1 = __last;
+    for (--__lm1; __first != __lm1; ++__first)
+    {
+        _BirdirectionalIterator __i = _VSTD::min_element<_BirdirectionalIterator,
+                                                        typename add_lvalue_reference<_Compare>::type>
+                                                       (__first, __last, __comp);
+        if (__i != __first)
+            swap(*__first, *__i);
+    }
+}
+
+template <class _Compare, class _BirdirectionalIterator>
+void
+__insertion_sort(_BirdirectionalIterator __first, _BirdirectionalIterator __last, _Compare __comp)
+{
+    typedef typename iterator_traits<_BirdirectionalIterator>::value_type value_type;
+    if (__first != __last)
+    {
+        _BirdirectionalIterator __i = __first;
+        for (++__i; __i != __last; ++__i)
+        {
+            _BirdirectionalIterator __j = __i;
+            value_type __t(_VSTD::move(*__j));
+            for (_BirdirectionalIterator __k = __i; __k != __first && __comp(__t,  *--__k); --__j)
+                *__j = _VSTD::move(*__k);
+            *__j = _VSTD::move(__t);
+        }
+    }
+}
+
+template <class _Compare, class _RandomAccessIterator>
+void
+__insertion_sort_3(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
+{
+    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
+    _RandomAccessIterator __j = __first+2;
+    __sort3<_Compare>(__first, __first+1, __j, __comp);
+    for (_RandomAccessIterator __i = __j+1; __i != __last; ++__i)
+    {
+        if (__comp(*__i, *__j))
+        {
+            value_type __t(_VSTD::move(*__i));
+            _RandomAccessIterator __k = __j;
+            __j = __i;
+            do
+            {
+                *__j = _VSTD::move(*__k);
+                __j = __k;
+            } while (__j != __first && __comp(__t, *--__k));
+            *__j = _VSTD::move(__t);
+        }
+        __j = __i;
+    }
+}
+
+template <class _Compare, class _RandomAccessIterator>
+bool
+__insertion_sort_incomplete(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
+{
+    switch (__last - __first)
+    {
+    case 0:
+    case 1:
+        return true;
+    case 2:
+        if (__comp(*--__last, *__first))
+            swap(*__first, *__last);
+        return true;
+    case 3:
+        _VSTD::__sort3<_Compare>(__first, __first+1, --__last, __comp);
+        return true;
+    case 4:
+        _VSTD::__sort4<_Compare>(__first, __first+1, __first+2, --__last, __comp);
+        return true;
+    case 5:
+        _VSTD::__sort5<_Compare>(__first, __first+1, __first+2, __first+3, --__last, __comp);
+        return true;
+    }
+    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
+    _RandomAccessIterator __j = __first+2;
+    __sort3<_Compare>(__first, __first+1, __j, __comp);
+    const unsigned __limit = 8;
+    unsigned __count = 0;
+    for (_RandomAccessIterator __i = __j+1; __i != __last; ++__i)
+    {
+        if (__comp(*__i, *__j))
+        {
+            value_type __t(_VSTD::move(*__i));
+            _RandomAccessIterator __k = __j;
+            __j = __i;
+            do
+            {
+                *__j = _VSTD::move(*__k);
+                __j = __k;
+            } while (__j != __first && __comp(__t, *--__k));
+            *__j = _VSTD::move(__t);
+            if (++__count == __limit)
+                return ++__i == __last;
+        }
+        __j = __i;
+    }
+    return true;
+}
+
+template <class _Compare, class _BirdirectionalIterator>
+void
+__insertion_sort_move(_BirdirectionalIterator __first1, _BirdirectionalIterator __last1,
+                      typename iterator_traits<_BirdirectionalIterator>::value_type* __first2, _Compare __comp)
+{
+    typedef typename iterator_traits<_BirdirectionalIterator>::value_type value_type;
+    if (__first1 != __last1)
+    {
+        __destruct_n __d(0);
+        unique_ptr<value_type, __destruct_n&> __h(__first2, __d);
+        value_type* __last2 = __first2;
+        ::new(__last2) value_type(_VSTD::move(*__first1));
+        __d.__incr((value_type*)0);
+        for (++__last2; ++__first1 != __last1; ++__last2)
+        {
+            value_type* __j2 = __last2;
+            value_type* __i2 = __j2;
+            if (__comp(*__first1, *--__i2))
+            {
+                ::new(__j2) value_type(_VSTD::move(*__i2));
+                __d.__incr((value_type*)0);
+                for (--__j2; __i2 != __first2 && __comp(*__first1,  *--__i2); --__j2)
+                    *__j2 = _VSTD::move(*__i2);
+                *__j2 = _VSTD::move(*__first1);
+            }
+            else
+            {
+                ::new(__j2) value_type(_VSTD::move(*__first1));
+                __d.__incr((value_type*)0);
+            }
+        }
+        __h.release();
+    }
+}
+
+template <class _Compare, class _RandomAccessIterator>
+void
+__sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
+{
+    // _Compare is known to be a reference type
+    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
+    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
+    const difference_type __limit = is_trivially_copy_constructible<value_type>::value &&
+                                    is_trivially_copy_assignable<value_type>::value ? 30 : 6;
+    while (true)
+    {
+    __restart:
+        difference_type __len = __last - __first;
+        switch (__len)
+        {
+        case 0:
+        case 1:
+            return;
+        case 2:
+            if (__comp(*--__last, *__first))
+                swap(*__first, *__last);
+            return;
+        case 3:
+            _VSTD::__sort3<_Compare>(__first, __first+1, --__last, __comp);
+            return;
+        case 4:
+            _VSTD::__sort4<_Compare>(__first, __first+1, __first+2, --__last, __comp);
+            return;
+        case 5:
+            _VSTD::__sort5<_Compare>(__first, __first+1, __first+2, __first+3, --__last, __comp);
+            return;
+        }
+        if (__len <= __limit)
+        {
+            _VSTD::__insertion_sort_3<_Compare>(__first, __last, __comp);
+            return;
+        }
+        // __len > 5
+        _RandomAccessIterator __m = __first;
+        _RandomAccessIterator __lm1 = __last;
+        --__lm1;
+        unsigned __n_swaps;
+        {
+        difference_type __delta;
+        if (__len >= 1000)
+        {
+            __delta = __len/2;
+            __m += __delta;
+            __delta /= 2;
+            __n_swaps = _VSTD::__sort5<_Compare>(__first, __first + __delta, __m, __m+__delta, __lm1, __comp);
+        }
+        else
+        {
+            __delta = __len/2;
+            __m += __delta;
+            __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, __lm1, __comp);
+        }
+        }
+        // *__m is median
+        // partition [__first, __m) < *__m and *__m <= [__m, __last)
+        // (this inhibits tossing elements equivalent to __m around unnecessarily)
+        _RandomAccessIterator __i = __first;
+        _RandomAccessIterator __j = __lm1;
+        // j points beyond range to be tested, *__m is known to be <= *__lm1
+        // The search going up is known to be guarded but the search coming down isn't.
+        // Prime the downward search with a guard.
+        if (!__comp(*__i, *__m))  // if *__first == *__m
+        {
+            // *__first == *__m, *__first doesn't go in first part
+            // manually guard downward moving __j against __i
+            while (true)
+            {
+                if (__i == --__j)
+                {
+                    // *__first == *__m, *__m <= all other elements
+                    // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
+                    ++__i;  // __first + 1
+                    __j = __last;
+                    if (!__comp(*__first, *--__j))  // we need a guard if *__first == *(__last-1)
+                    {
+                        while (true)
+                        {
+                            if (__i == __j)
+                                return;  // [__first, __last) all equivalent elements
+                            if (__comp(*__first, *__i))
+                            {
+                                swap(*__i, *__j);
+                                ++__n_swaps;
+                                ++__i;
+                                break;
+                            }
+                            ++__i;
+                        }
+                    }
+                    // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
+                    if (__i == __j)
+                        return;
+                    while (true)
+                    {
+                        while (!__comp(*__first, *__i))
+                            ++__i;
+                        while (__comp(*__first, *--__j))
+                            ;
+                        if (__i >= __j)
+                            break;
+                        swap(*__i, *__j);
+                        ++__n_swaps;
+                        ++__i;
+                    }
+                    // [__first, __i) == *__first and *__first < [__i, __last)
+                    // The first part is sorted, sort the secod part
+                    // _VSTD::__sort<_Compare>(__i, __last, __comp);
+                    __first = __i;
+                    goto __restart;
+                }
+                if (__comp(*__j, *__m))
+                {
+                    swap(*__i, *__j);
+                    ++__n_swaps;
+                    break;  // found guard for downward moving __j, now use unguarded partition
+                }
+            }
+        }
+        // It is known that *__i < *__m
+        ++__i;
+        // j points beyond range to be tested, *__m is known to be <= *__lm1
+        // if not yet partitioned...
+        if (__i < __j)
+        {
+            // known that *(__i - 1) < *__m
+            // known that __i <= __m
+            while (true)
+            {
+                // __m still guards upward moving __i
+                while (__comp(*__i, *__m))
+                    ++__i;
+                // It is now known that a guard exists for downward moving __j
+                while (!__comp(*--__j, *__m))
+                    ;
+                if (__i > __j)
+                    break;
+                swap(*__i, *__j);
+                ++__n_swaps;
+                // It is known that __m != __j
+                // If __m just moved, follow it
+                if (__m == __i)
+                    __m = __j;
+                ++__i;
+            }
+        }
+        // [__first, __i) < *__m and *__m <= [__i, __last)
+        if (__i != __m && __comp(*__m, *__i))
+        {
+            swap(*__i, *__m);
+            ++__n_swaps;
+        }
+        // [__first, __i) < *__i and *__i <= [__i+1, __last)
+        // If we were given a perfect partition, see if insertion sort is quick...
+        if (__n_swaps == 0)
+        {
+            bool __fs = _VSTD::__insertion_sort_incomplete<_Compare>(__first, __i, __comp);
+            if (_VSTD::__insertion_sort_incomplete<_Compare>(__i+1, __last, __comp))
+            {
+                if (__fs)
+                    return;
+                __last = __i;
+                continue;
+            }
+            else
+            {
+                if (__fs)
+                {
+                    __first = ++__i;
+                    continue;
+                }
+            }
+        }
+        // sort smaller range with recursive call and larger with tail recursion elimination
+        if (__i - __first < __last - __i)
+        {
+            _VSTD::__sort<_Compare>(__first, __i, __comp);
+            // _VSTD::__sort<_Compare>(__i+1, __last, __comp);
+            __first = ++__i;
+        }
+        else
+        {
+            _VSTD::__sort<_Compare>(__i+1, __last, __comp);
+            // _VSTD::__sort<_Compare>(__first, __i, __comp);
+            __last = __i;
+        }
+    }
+}
+
+// This forwarder keeps the top call and the recursive calls using the same instantiation, forcing a reference _Compare
+template <class _RandomAccessIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    __sort<_Comp_ref>(__first, __last, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    __sort<_Comp_ref>(__first, __last, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _RandomAccessIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
+{
+    _VSTD::sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+sort(_Tp** __first, _Tp** __last)
+{
+    _VSTD::sort((size_t*)__first, (size_t*)__last, __less<size_t>());
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+sort(__wrap_iter<_Tp*> __first, __wrap_iter<_Tp*> __last)
+{
+    _VSTD::sort(__first.base(), __last.base());
+}
+
+template <class _Tp, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+sort(__wrap_iter<_Tp*> __first, __wrap_iter<_Tp*> __last, _Compare __comp)
+{
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    _VSTD::sort<_Tp*, _Comp_ref>(__first.base(), __last.base(), __comp);
+}
+
+#ifdef _LIBCPP_MSVC
+#pragma warning( push )
+#pragma warning( disable: 4231)
+#endif // _LIBCPP_MSVC
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<char>&, char*>(char*, char*, __less<char>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<short>&, short*>(short*, short*, __less<short>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<int>&, int*>(int*, int*, __less<int>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long>&, long*>(long*, long*, __less<long>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned long long>&, unsigned long long*>(unsigned long long*, unsigned long long*, __less<unsigned long long>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<float>&, float*>(float*, float*, __less<float>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<double>&, double*>(double*, double*, __less<double>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))
+
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<char>&, char*>(char*, char*, __less<char>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<short>&, short*>(short*, short*, __less<short>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<int>&, int*>(int*, int*, __less<int>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long>&, long*>(long*, long*, __less<long>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long long>&, unsigned long long*>(unsigned long long*, unsigned long long*, __less<unsigned long long>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<float>&, float*>(float*, float*, __less<float>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<double>&, double*>(double*, double*, __less<double>&))
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))
+
+_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS unsigned __sort5<__less<long double>&, long double*>(long double*, long double*, long double*, long double*, long double*, __less<long double>&))
+#ifdef _LIBCPP_MSVC
+#pragma warning( pop )
+#endif  // _LIBCPP_MSVC
+
+// lower_bound
+
+template <class _Compare, class _ForwardIterator, class _Tp>
+_ForwardIterator
+__lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
+{
+    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
+    difference_type __len = _VSTD::distance(__first, __last);
+    while (__len != 0)
+    {
+        difference_type __l2 = __len / 2;
+        _ForwardIterator __m = __first;
+        _VSTD::advance(__m, __l2);
+        if (__comp(*__m, __value_))
+        {
+            __first = ++__m;
+            __len -= __l2 + 1;
+        }
+        else
+            __len = __l2;
+    }
+    return __first;
+}
+
+template <class _ForwardIterator, class _Tp, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator
+lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    return __lower_bound<_Comp_ref>(__first, __last, __value_, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    return __lower_bound<_Comp_ref>(__first, __last, __value_, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _ForwardIterator, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator
+lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
+{
+    return _VSTD::lower_bound(__first, __last, __value_,
+                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
+}
+
+// upper_bound
+
+template <class _Compare, class _ForwardIterator, class _Tp>
+_ForwardIterator
+__upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
+{
+    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
+    difference_type __len = _VSTD::distance(__first, __last);
+    while (__len != 0)
+    {
+        difference_type __l2 = __len / 2;
+        _ForwardIterator __m = __first;
+        _VSTD::advance(__m, __l2);
+        if (__comp(__value_, *__m))
+            __len = __l2;
+        else
+        {
+            __first = ++__m;
+            __len -= __l2 + 1;
+        }
+    }
+    return __first;
+}
+
+template <class _ForwardIterator, class _Tp, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator
+upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    return __upper_bound<_Comp_ref>(__first, __last, __value_, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    return __upper_bound<_Comp_ref>(__first, __last, __value_, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _ForwardIterator, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIterator
+upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
+{
+    return _VSTD::upper_bound(__first, __last, __value_,
+                             __less<_Tp, typename iterator_traits<_ForwardIterator>::value_type>());
+}
+
+// equal_range
+
+template <class _Compare, class _ForwardIterator, class _Tp>
+pair<_ForwardIterator, _ForwardIterator>
+__equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
+{
+    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
+    difference_type __len = _VSTD::distance(__first, __last);
+    while (__len != 0)
+    {
+        difference_type __l2 = __len / 2;
+        _ForwardIterator __m = __first;
+        _VSTD::advance(__m, __l2);
+        if (__comp(*__m, __value_))
+        {
+            __first = ++__m;
+            __len -= __l2 + 1;
+        }
+        else if (__comp(__value_, *__m))
+        {
+            __last = __m;
+            __len = __l2;
+        }
+        else
+        {
+            _ForwardIterator __mp1 = __m;
+            return pair<_ForwardIterator, _ForwardIterator>
+                   (
+                      __lower_bound<_Compare>(__first, __m, __value_, __comp),
+                      __upper_bound<_Compare>(++__mp1, __last, __value_, __comp)
+                   );
+        }
+    }
+    return pair<_ForwardIterator, _ForwardIterator>(__first, __first);
+}
+
+template <class _ForwardIterator, class _Tp, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+pair<_ForwardIterator, _ForwardIterator>
+equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    return __equal_range<_Comp_ref>(__first, __last, __value_, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    return __equal_range<_Comp_ref>(__first, __last, __value_, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _ForwardIterator, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+pair<_ForwardIterator, _ForwardIterator>
+equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
+{
+    return _VSTD::equal_range(__first, __last, __value_,
+                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
+}
+
+// binary_search
+
+template <class _Compare, class _ForwardIterator, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+__binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
+{
+    __first = __lower_bound<_Compare>(__first, __last, __value_, __comp);
+    return __first != __last && !__comp(__value_, *__first);
+}
+
+template <class _ForwardIterator, class _Tp, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    return __binary_search<_Comp_ref>(__first, __last, __value_, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    return __binary_search<_Comp_ref>(__first, __last, __value_, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _ForwardIterator, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
+{
+    return _VSTD::binary_search(__first, __last, __value_,
+                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
+}
+
+// merge
+
+template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
+_OutputIterator
+__merge(_InputIterator1 __first1, _InputIterator1 __last1,
+        _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
+{
+    for (; __first1 != __last1; ++__result)
+    {
+        if (__first2 == __last2)
+            return _VSTD::copy(__first1, __last1, __result);
+        if (__comp(*__first2, *__first1))
+        {
+            *__result = *__first2;
+            ++__first2;
+        }
+        else
+        {
+            *__result = *__first1;
+            ++__first1;
+        }
+    }
+    return _VSTD::copy(__first2, __last2, __result);
+}
+
+template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+merge(_InputIterator1 __first1, _InputIterator1 __last1,
+      _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    return _VSTD::__merge<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    return _VSTD::__merge<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+merge(_InputIterator1 __first1, _InputIterator1 __last1,
+      _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
+{
+    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
+    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
+    return merge(__first1, __last1, __first2, __last2, __result, __less<__v1, __v2>());
+}
+
+// inplace_merge
+
+template <class _Compare, class _InputIterator1, class _InputIterator2,
+          class _OutputIterator>
+void __half_inplace_merge(_InputIterator1 __first1, _InputIterator1 __last1,
+                          _InputIterator2 __first2, _InputIterator2 __last2,
+                          _OutputIterator __result, _Compare __comp)
+{
+    for (; __first1 != __last1; ++__result)
+    {
+        if (__first2 == __last2)
+        {
+            _VSTD::move(__first1, __last1, __result);
+            return;
+        }
+
+        if (__comp(*__first2, *__first1))
+        {
+            *__result = _VSTD::move(*__first2);
+            ++__first2;
+        }
+        else
+        {
+            *__result = _VSTD::move(*__first1);
+            ++__first1;
+        }
+    }
+    // __first2 through __last2 are already in the right spot.
+}
+
+template <class _Compare, class _BidirectionalIterator>
+void
+__buffered_inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
+                _Compare __comp, typename iterator_traits<_BidirectionalIterator>::difference_type __len1,
+                                 typename iterator_traits<_BidirectionalIterator>::difference_type __len2,
+                typename iterator_traits<_BidirectionalIterator>::value_type* __buff)
+{
+    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
+    __destruct_n __d(0);
+    unique_ptr<value_type, __destruct_n&> __h2(__buff, __d);
+    if (__len1 <= __len2)
+    {
+        value_type* __p = __buff;
+        for (_BidirectionalIterator __i = __first; __i != __middle; __d.__incr((value_type*)0), (void) ++__i, ++__p)
+            ::new(__p) value_type(_VSTD::move(*__i));
+        __half_inplace_merge(__buff, __p, __middle, __last, __first, __comp);
+    }
+    else
+    {
+        value_type* __p = __buff;
+        for (_BidirectionalIterator __i = __middle; __i != __last; __d.__incr((value_type*)0), (void) ++__i, ++__p)
+            ::new(__p) value_type(_VSTD::move(*__i));
+        typedef reverse_iterator<_BidirectionalIterator> _RBi;
+        typedef reverse_iterator<value_type*> _Rv;
+        __half_inplace_merge(_Rv(__p), _Rv(__buff), 
+                             _RBi(__middle), _RBi(__first),
+                             _RBi(__last), __negate<_Compare>(__comp));
+    }
+}
+
+template <class _Compare, class _BidirectionalIterator>
+void
+__inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
+                _Compare __comp, typename iterator_traits<_BidirectionalIterator>::difference_type __len1,
+                                 typename iterator_traits<_BidirectionalIterator>::difference_type __len2,
+                typename iterator_traits<_BidirectionalIterator>::value_type* __buff, ptrdiff_t __buff_size)
+{
+    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
+    while (true)
+    {
+        // if __middle == __last, we're done
+        if (__len2 == 0)
+            return;
+        if (__len1 <= __buff_size || __len2 <= __buff_size)
+            return __buffered_inplace_merge<_Compare>
+                   (__first, __middle, __last, __comp, __len1, __len2, __buff);
+        // shrink [__first, __middle) as much as possible (with no moves), returning if it shrinks to 0
+        for (; true; ++__first, (void) --__len1)
+        {
+            if (__len1 == 0)
+                return;
+            if (__comp(*__middle, *__first))
+                break;
+        }
+        // __first < __middle < __last
+        // *__first > *__middle
+        // partition [__first, __m1) [__m1, __middle) [__middle, __m2) [__m2, __last) such that
+        //     all elements in:
+        //         [__first, __m1)  <= [__middle, __m2)
+        //         [__middle, __m2) <  [__m1, __middle)
+        //         [__m1, __middle) <= [__m2, __last)
+        //     and __m1 or __m2 is in the middle of its range
+        _BidirectionalIterator __m1;  // "median" of [__first, __middle)
+        _BidirectionalIterator __m2;  // "median" of [__middle, __last)
+        difference_type __len11;      // distance(__first, __m1)
+        difference_type __len21;      // distance(__middle, __m2)
+        // binary search smaller range
+        if (__len1 < __len2)
+        {   // __len >= 1, __len2 >= 2
+            __len21 = __len2 / 2;
+            __m2 = __middle;
+            _VSTD::advance(__m2, __len21);
+            __m1 = __upper_bound<_Compare>(__first, __middle, *__m2, __comp);
+            __len11 = _VSTD::distance(__first, __m1);
+        }
+        else
+        {
+            if (__len1 == 1)
+            {   // __len1 >= __len2 && __len2 > 0, therefore __len2 == 1
+                // It is known *__first > *__middle
+                swap(*__first, *__middle);
+                return;
+            }
+            // __len1 >= 2, __len2 >= 1
+            __len11 = __len1 / 2;
+            __m1 = __first;
+            _VSTD::advance(__m1, __len11);
+            __m2 = __lower_bound<_Compare>(__middle, __last, *__m1, __comp);
+            __len21 = _VSTD::distance(__middle, __m2);
+        }
+        difference_type __len12 = __len1 - __len11;  // distance(__m1, __middle)
+        difference_type __len22 = __len2 - __len21;  // distance(__m2, __last)
+        // [__first, __m1) [__m1, __middle) [__middle, __m2) [__m2, __last)
+        // swap middle two partitions
+        __middle = _VSTD::rotate(__m1, __middle, __m2);
+        // __len12 and __len21 now have swapped meanings
+        // merge smaller range with recurisve call and larger with tail recursion elimination
+        if (__len11 + __len21 < __len12 + __len22)
+        {
+            __inplace_merge<_Compare>(__first, __m1, __middle, __comp, __len11, __len21, __buff, __buff_size);
+//          __inplace_merge<_Compare>(__middle, __m2, __last, __comp, __len12, __len22, __buff, __buff_size);
+            __first = __middle;
+            __middle = __m2;
+            __len1 = __len12;
+            __len2 = __len22;
+        }
+        else
+        {
+            __inplace_merge<_Compare>(__middle, __m2, __last, __comp, __len12, __len22, __buff, __buff_size);
+//          __inplace_merge<_Compare>(__first, __m1, __middle, __comp, __len11, __len21, __buff, __buff_size);
+            __last = __middle;
+            __middle = __m1;
+            __len1 = __len11;
+            __len2 = __len21;
+        }
+    }
+}
+
+template <class _BidirectionalIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
+              _Compare __comp)
+{
+    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
+    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
+    difference_type __len1 = _VSTD::distance(__first, __middle);
+    difference_type __len2 = _VSTD::distance(__middle, __last);
+    difference_type __buf_size = _VSTD::min(__len1, __len2);
+    pair<value_type*, ptrdiff_t> __buf = _VSTD::get_temporary_buffer<value_type>(__buf_size);
+    unique_ptr<value_type, __return_temporary_buffer> __h(__buf.first);
+
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    return _VSTD::__inplace_merge<_Comp_ref>(__first, __middle, __last, __c, __len1, __len2,
+                                            __buf.first, __buf.second);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    return _VSTD::__inplace_merge<_Comp_ref>(__first, __middle, __last, __comp, __len1, __len2,
+                                            __buf.first, __buf.second);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _BidirectionalIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last)
+{
+    _VSTD::inplace_merge(__first, __middle, __last,
+                        __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
+}
+
+// stable_sort
+
+template <class _Compare, class _InputIterator1, class _InputIterator2>
+void
+__merge_move_construct(_InputIterator1 __first1, _InputIterator1 __last1,
+        _InputIterator2 __first2, _InputIterator2 __last2,
+        typename iterator_traits<_InputIterator1>::value_type* __result, _Compare __comp)
+{
+    typedef typename iterator_traits<_InputIterator1>::value_type value_type;
+    __destruct_n __d(0);
+    unique_ptr<value_type, __destruct_n&> __h(__result, __d);
+    for (; true; ++__result)
+    {
+        if (__first1 == __last1)
+        {
+            for (; __first2 != __last2; ++__first2, ++__result, __d.__incr((value_type*)0))
+                ::new (__result) value_type(_VSTD::move(*__first2));
+            __h.release();
+            return;
+        }
+        if (__first2 == __last2)
+        {
+            for (; __first1 != __last1; ++__first1, ++__result, __d.__incr((value_type*)0))
+                ::new (__result) value_type(_VSTD::move(*__first1));
+            __h.release();
+            return;
+        }
+        if (__comp(*__first2, *__first1))
+        {
+            ::new (__result) value_type(_VSTD::move(*__first2));
+            __d.__incr((value_type*)0);
+            ++__first2;
+        }
+        else
+        {
+            ::new (__result) value_type(_VSTD::move(*__first1));
+            __d.__incr((value_type*)0);
+            ++__first1;
+        }
+    }
+}
+
+template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
+void
+__merge_move_assign(_InputIterator1 __first1, _InputIterator1 __last1,
+        _InputIterator2 __first2, _InputIterator2 __last2,
+        _OutputIterator __result, _Compare __comp)
+{
+    for (; __first1 != __last1; ++__result)
+    {
+        if (__first2 == __last2)
+        {
+            for (; __first1 != __last1; ++__first1, ++__result)
+                *__result = _VSTD::move(*__first1);
+            return;
+        }
+        if (__comp(*__first2, *__first1))
+        {
+            *__result = _VSTD::move(*__first2);
+            ++__first2;
+        }
+        else
+        {
+            *__result = _VSTD::move(*__first1);
+            ++__first1;
+        }
+    }
+    for (; __first2 != __last2; ++__first2, ++__result)
+        *__result = _VSTD::move(*__first2);
+}
+
+template <class _Compare, class _RandomAccessIterator>
+void
+__stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
+              typename iterator_traits<_RandomAccessIterator>::difference_type __len,
+              typename iterator_traits<_RandomAccessIterator>::value_type* __buff, ptrdiff_t __buff_size);
+
+template <class _Compare, class _RandomAccessIterator>
+void
+__stable_sort_move(_RandomAccessIterator __first1, _RandomAccessIterator __last1, _Compare __comp,
+                   typename iterator_traits<_RandomAccessIterator>::difference_type __len,
+                   typename iterator_traits<_RandomAccessIterator>::value_type* __first2)
+{
+    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
+    switch (__len)
+    {
+    case 0:
+        return;
+    case 1:
+        ::new(__first2) value_type(_VSTD::move(*__first1));
+        return;
+    case 2:
+       __destruct_n __d(0);
+        unique_ptr<value_type, __destruct_n&> __h2(__first2, __d);
+         if (__comp(*--__last1, *__first1))
+        {
+            ::new(__first2) value_type(_VSTD::move(*__last1));
+            __d.__incr((value_type*)0);
+            ++__first2;
+            ::new(__first2) value_type(_VSTD::move(*__first1));
+        }
+        else
+        {
+            ::new(__first2) value_type(_VSTD::move(*__first1));
+            __d.__incr((value_type*)0);
+            ++__first2;
+            ::new(__first2) value_type(_VSTD::move(*__last1));
+        }
+        __h2.release();
+        return;
+    }
+    if (__len <= 8)
+    {
+        __insertion_sort_move<_Compare>(__first1, __last1, __first2, __comp);
+        return;
+    }
+    typename iterator_traits<_RandomAccessIterator>::difference_type __l2 = __len / 2;
+    _RandomAccessIterator __m = __first1 + __l2;
+    __stable_sort<_Compare>(__first1, __m, __comp, __l2, __first2, __l2);
+    __stable_sort<_Compare>(__m, __last1, __comp, __len - __l2, __first2 + __l2, __len - __l2);
+    __merge_move_construct<_Compare>(__first1, __m, __m, __last1, __first2, __comp);
+}
+
+template <class _Tp>
+struct __stable_sort_switch
+{
+    static const unsigned value = 128*is_trivially_copy_assignable<_Tp>::value;
+};
+
+template <class _Compare, class _RandomAccessIterator>
+void
+__stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
+              typename iterator_traits<_RandomAccessIterator>::difference_type __len,
+              typename iterator_traits<_RandomAccessIterator>::value_type* __buff, ptrdiff_t __buff_size)
+{
+    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
+    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
+    switch (__len)
+    {
+    case 0:
+    case 1:
+        return;
+    case 2:
+        if (__comp(*--__last, *__first))
+            swap(*__first, *__last);
+        return;
+    }
+    if (__len <= static_cast<difference_type>(__stable_sort_switch<value_type>::value))
+    {
+        __insertion_sort<_Compare>(__first, __last, __comp);
+        return;
+    }
+    typename iterator_traits<_RandomAccessIterator>::difference_type __l2 = __len / 2;
+    _RandomAccessIterator __m = __first + __l2;
+    if (__len <= __buff_size)
+    {
+        __destruct_n __d(0);
+        unique_ptr<value_type, __destruct_n&> __h2(__buff, __d);
+        __stable_sort_move<_Compare>(__first, __m, __comp, __l2, __buff);
+        __d.__set(__l2, (value_type*)0);
+        __stable_sort_move<_Compare>(__m, __last, __comp, __len - __l2, __buff + __l2);
+        __d.__set(__len, (value_type*)0);
+        __merge_move_assign<_Compare>(__buff, __buff + __l2, __buff + __l2, __buff + __len, __first, __comp);
+//         __merge<_Compare>(move_iterator<value_type*>(__buff),
+//                           move_iterator<value_type*>(__buff + __l2),
+//                           move_iterator<_RandomAccessIterator>(__buff + __l2),
+//                           move_iterator<_RandomAccessIterator>(__buff + __len),
+//                           __first, __comp);
+        return;
+    }
+    __stable_sort<_Compare>(__first, __m, __comp, __l2, __buff, __buff_size);
+    __stable_sort<_Compare>(__m, __last, __comp, __len - __l2, __buff, __buff_size);
+    __inplace_merge<_Compare>(__first, __m, __last, __comp, __l2, __len - __l2, __buff, __buff_size);
+}
+
+template <class _RandomAccessIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
+{
+    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
+    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
+    difference_type __len = __last - __first;
+    pair<value_type*, ptrdiff_t> __buf(0, 0);
+    unique_ptr<value_type, __return_temporary_buffer> __h;
+    if (__len > static_cast<difference_type>(__stable_sort_switch<value_type>::value))
+    {
+        __buf = _VSTD::get_temporary_buffer<value_type>(__len);
+        __h.reset(__buf.first);
+    }
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    __stable_sort<_Comp_ref>(__first, __last, __c, __len, __buf.first, __buf.second);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    __stable_sort<_Comp_ref>(__first, __last, __comp, __len, __buf.first, __buf.second);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _RandomAccessIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
+{
+    _VSTD::stable_sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
+}
+
+// is_heap_until
+
+template <class _RandomAccessIterator, class _Compare>
+_RandomAccessIterator
+is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
+{
+    typedef typename _VSTD::iterator_traits<_RandomAccessIterator>::difference_type difference_type;
+    difference_type __len = __last - __first;
+    difference_type __p = 0;
+    difference_type __c = 1;
+    _RandomAccessIterator __pp = __first;
+    while (__c < __len)
+    {
+        _RandomAccessIterator __cp = __first + __c;
+        if (__comp(*__pp, *__cp))
+            return __cp;
+        ++__c;
+        ++__cp;
+        if (__c == __len)
+            return __last;
+        if (__comp(*__pp, *__cp))
+            return __cp;
+        ++__p;
+        ++__pp;
+        __c = 2 * __p + 1;
+    }
+    return __last;
+}
+
+template<class _RandomAccessIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_RandomAccessIterator
+is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last)
+{
+    return _VSTD::is_heap_until(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
+}
+
+// is_heap
+
+template <class _RandomAccessIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
+{
+    return _VSTD::is_heap_until(__first, __last, __comp) == __last;
+}
+
+template<class _RandomAccessIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
+{
+    return _VSTD::is_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
+}
+
+// push_heap
+
+template <class _Compare, class _RandomAccessIterator>
+void
+__sift_up(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
+          typename iterator_traits<_RandomAccessIterator>::difference_type __len)
+{
+    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
+    if (__len > 1)
+    {
+        __len = (__len - 2) / 2;
+        _RandomAccessIterator __ptr = __first + __len;
+        if (__comp(*__ptr, *--__last))
+        {
+            value_type __t(_VSTD::move(*__last));
+            do
+            {
+                *__last = _VSTD::move(*__ptr);
+                __last = __ptr;
+                if (__len == 0)
+                    break;
+                __len = (__len - 1) / 2;
+                __ptr = __first + __len;
+            } while (__comp(*__ptr, __t));
+            *__last = _VSTD::move(__t);
+        }
+    }
+}
+
+template <class _RandomAccessIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    __sift_up<_Comp_ref>(__first, __last, __c, __last - __first);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    __sift_up<_Comp_ref>(__first, __last, __comp, __last - __first);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _RandomAccessIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
+{
+    _VSTD::push_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
+}
+
+// pop_heap
+
+template <class _Compare, class _RandomAccessIterator>
+void
+__sift_down(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
+            typename iterator_traits<_RandomAccessIterator>::difference_type __len,
+            _RandomAccessIterator __start)
+{
+    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
+    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
+    // left-child of __start is at 2 * __start + 1
+    // right-child of __start is at 2 * __start + 2
+    difference_type __child = __start - __first;
+
+    if (__len < 2 || (__len - 2) / 2 < __child)
+        return;
+
+    __child = 2 * __child + 1;
+    _RandomAccessIterator __child_i = __first + __child;
+
+    if ((__child + 1) < __len && __comp(*__child_i, *(__child_i + 1))) {
+        // right-child exists and is greater than left-child
+        ++__child_i;
+        ++__child;
+    }
+
+    // check if we are in heap-order
+    if (__comp(*__child_i, *__start))
+        // we are, __start is larger than it's largest child
+        return;
+
+    value_type __top(_VSTD::move(*__start));
+    do
+    {
+        // we are not in heap-order, swap the parent with it's largest child
+        *__start = _VSTD::move(*__child_i);
+        __start = __child_i;
+
+        if ((__len - 2) / 2 < __child)
+            break;
+
+        // recompute the child based off of the updated parent
+        __child = 2 * __child + 1;
+        __child_i = __first + __child;
+
+        if ((__child + 1) < __len && __comp(*__child_i, *(__child_i + 1))) {
+            // right-child exists and is greater than left-child
+            ++__child_i;
+            ++__child;
+        }
+
+        // check if we are in heap-order
+    } while (!__comp(*__child_i, __top));
+    *__start = _VSTD::move(__top);
+}
+
+template <class _Compare, class _RandomAccessIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
+           typename iterator_traits<_RandomAccessIterator>::difference_type __len)
+{
+    if (__len > 1)
+    {
+        swap(*__first, *--__last);
+        __sift_down<_Compare>(__first, __last, __comp, __len - 1, __first);
+    }
+}
+
+template <class _RandomAccessIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    __pop_heap<_Comp_ref>(__first, __last, __c, __last - __first);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    __pop_heap<_Comp_ref>(__first, __last, __comp, __last - __first);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _RandomAccessIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
+{
+    _VSTD::pop_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
+}
+
+// make_heap
+
+template <class _Compare, class _RandomAccessIterator>
+void
+__make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
+{
+    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
+    difference_type __n = __last - __first;
+    if (__n > 1)
+    {
+        // start from the first parent, there is no need to consider children
+        for (difference_type __start = (__n - 2) / 2; __start >= 0; --__start)
+        {
+            __sift_down<_Compare>(__first, __last, __comp, __n, __first + __start);
+        }
+    }
+}
+
+template <class _RandomAccessIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    __make_heap<_Comp_ref>(__first, __last, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    __make_heap<_Comp_ref>(__first, __last, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _RandomAccessIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
+{
+    _VSTD::make_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
+}
+
+// sort_heap
+
+template <class _Compare, class _RandomAccessIterator>
+void
+__sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
+{
+    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
+    for (difference_type __n = __last - __first; __n > 1; --__last, --__n)
+        __pop_heap<_Compare>(__first, __last, __comp, __n);
+}
+
+template <class _RandomAccessIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    __sort_heap<_Comp_ref>(__first, __last, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    __sort_heap<_Comp_ref>(__first, __last, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _RandomAccessIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
+{
+    _VSTD::sort_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
+}
+
+// partial_sort
+
+template <class _Compare, class _RandomAccessIterator>
+void
+__partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
+             _Compare __comp)
+{
+    __make_heap<_Compare>(__first, __middle, __comp);
+    typename iterator_traits<_RandomAccessIterator>::difference_type __len = __middle - __first;
+    for (_RandomAccessIterator __i = __middle; __i != __last; ++__i)
+    {
+        if (__comp(*__i, *__first))
+        {
+            swap(*__i, *__first);
+            __sift_down<_Compare>(__first, __middle, __comp, __len, __first);
+        }
+    }
+    __sort_heap<_Compare>(__first, __middle, __comp);
+}
+
+template <class _RandomAccessIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
+             _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    __partial_sort<_Comp_ref>(__first, __middle, __last, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    __partial_sort<_Comp_ref>(__first, __middle, __last, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _RandomAccessIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
+{
+    _VSTD::partial_sort(__first, __middle, __last,
+                       __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
+}
+
+// partial_sort_copy
+
+template <class _Compare, class _InputIterator, class _RandomAccessIterator>
+_RandomAccessIterator
+__partial_sort_copy(_InputIterator __first, _InputIterator __last,
+                    _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp)
+{
+    _RandomAccessIterator __r = __result_first;
+    if (__r != __result_last)
+    {
+        for (; __first != __last && __r != __result_last; (void) ++__first, ++__r)
+            *__r = *__first;
+        __make_heap<_Compare>(__result_first, __r, __comp);
+        typename iterator_traits<_RandomAccessIterator>::difference_type __len = __r - __result_first;
+        for (; __first != __last; ++__first)
+            if (__comp(*__first, *__result_first))
+            {
+                *__result_first = *__first;
+                __sift_down<_Compare>(__result_first, __r, __comp, __len, __result_first);
+            }
+        __sort_heap<_Compare>(__result_first, __r, __comp);
+    }
+    return __r;
+}
+
+template <class _InputIterator, class _RandomAccessIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+_RandomAccessIterator
+partial_sort_copy(_InputIterator __first, _InputIterator __last,
+                  _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    return __partial_sort_copy<_Comp_ref>(__first, __last, __result_first, __result_last, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    return __partial_sort_copy<_Comp_ref>(__first, __last, __result_first, __result_last, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _InputIterator, class _RandomAccessIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_RandomAccessIterator
+partial_sort_copy(_InputIterator __first, _InputIterator __last,
+                  _RandomAccessIterator __result_first, _RandomAccessIterator __result_last)
+{
+    return _VSTD::partial_sort_copy(__first, __last, __result_first, __result_last,
+                                   __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
+}
+
+// nth_element
+
+template <class _Compare, class _RandomAccessIterator>
+void
+__nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Compare __comp)
+{
+    // _Compare is known to be a reference type
+    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
+    const difference_type __limit = 7;
+    while (true)
+    {
+    __restart:
+        if (__nth == __last)
+            return;
+        difference_type __len = __last - __first;
+        switch (__len)
+        {
+        case 0:
+        case 1:
+            return;
+        case 2:
+            if (__comp(*--__last, *__first))
+                swap(*__first, *__last);
+            return;
+        case 3:
+            {
+            _RandomAccessIterator __m = __first;
+            _VSTD::__sort3<_Compare>(__first, ++__m, --__last, __comp);
+            return;
+            }
+        }
+        if (__len <= __limit)
+        {
+            __selection_sort<_Compare>(__first, __last, __comp);
+            return;
+        }
+        // __len > __limit >= 3
+        _RandomAccessIterator __m = __first + __len/2;
+        _RandomAccessIterator __lm1 = __last;
+        unsigned __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, --__lm1, __comp);
+        // *__m is median
+        // partition [__first, __m) < *__m and *__m <= [__m, __last)
+        // (this inhibits tossing elements equivalent to __m around unnecessarily)
+        _RandomAccessIterator __i = __first;
+        _RandomAccessIterator __j = __lm1;
+        // j points beyond range to be tested, *__lm1 is known to be <= *__m
+        // The search going up is known to be guarded but the search coming down isn't.
+        // Prime the downward search with a guard.
+        if (!__comp(*__i, *__m))  // if *__first == *__m
+        {
+            // *__first == *__m, *__first doesn't go in first part
+            // manually guard downward moving __j against __i
+            while (true)
+            {
+                if (__i == --__j)
+                {
+                    // *__first == *__m, *__m <= all other elements
+                    // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
+                    ++__i;  // __first + 1
+                    __j = __last;
+                    if (!__comp(*__first, *--__j))  // we need a guard if *__first == *(__last-1)
+                    {
+                        while (true)
+                        {
+                            if (__i == __j)
+                                return;  // [__first, __last) all equivalent elements
+                            if (__comp(*__first, *__i))
+                            {
+                                swap(*__i, *__j);
+                                ++__n_swaps;
+                                ++__i;
+                                break;
+                            }
+                            ++__i;
+                        }
+                    }
+                    // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
+                    if (__i == __j)
+                        return;
+                    while (true)
+                    {
+                        while (!__comp(*__first, *__i))
+                            ++__i;
+                        while (__comp(*__first, *--__j))
+                            ;
+                        if (__i >= __j)
+                            break;
+                        swap(*__i, *__j);
+                        ++__n_swaps;
+                        ++__i;
+                    }
+                    // [__first, __i) == *__first and *__first < [__i, __last)
+                    // The first part is sorted,
+                    if (__nth < __i)
+                        return;
+                    // __nth_element the secod part
+                    // __nth_element<_Compare>(__i, __nth, __last, __comp);
+                    __first = __i;
+                    goto __restart;
+                }
+                if (__comp(*__j, *__m))
+                {
+                    swap(*__i, *__j);
+                    ++__n_swaps;
+                    break;  // found guard for downward moving __j, now use unguarded partition
+                }
+            }
+        }
+        ++__i;
+        // j points beyond range to be tested, *__lm1 is known to be <= *__m
+        // if not yet partitioned...
+        if (__i < __j)
+        {
+            // known that *(__i - 1) < *__m
+            while (true)
+            {
+                // __m still guards upward moving __i
+                while (__comp(*__i, *__m))
+                    ++__i;
+                // It is now known that a guard exists for downward moving __j
+                while (!__comp(*--__j, *__m))
+                    ;
+                if (__i >= __j)
+                    break;
+                swap(*__i, *__j);
+                ++__n_swaps;
+                // It is known that __m != __j
+                // If __m just moved, follow it
+                if (__m == __i)
+                    __m = __j;
+                ++__i;
+            }
+        }
+        // [__first, __i) < *__m and *__m <= [__i, __last)
+        if (__i != __m && __comp(*__m, *__i))
+        {
+            swap(*__i, *__m);
+            ++__n_swaps;
+        }
+        // [__first, __i) < *__i and *__i <= [__i+1, __last)
+        if (__nth == __i)
+            return;
+        if (__n_swaps == 0)
+        {
+            // We were given a perfectly partitioned sequence.  Coincidence?
+            if (__nth < __i)
+            {
+                // Check for [__first, __i) already sorted
+                __j = __m = __first;
+                while (++__j != __i)
+                {
+                    if (__comp(*__j, *__m))
+                        // not yet sorted, so sort
+                        goto not_sorted;
+                    __m = __j;
+                }
+                // [__first, __i) sorted
+                return;
+            }
+            else
+            {
+                // Check for [__i, __last) already sorted
+                __j = __m = __i;
+                while (++__j != __last)
+                {
+                    if (__comp(*__j, *__m))
+                        // not yet sorted, so sort
+                        goto not_sorted;
+                    __m = __j;
+                }
+                // [__i, __last) sorted
+                return;
+            }
+        }
+not_sorted:
+        // __nth_element on range containing __nth
+        if (__nth < __i)
+        {
+            // __nth_element<_Compare>(__first, __nth, __i, __comp);
+            __last = __i;
+        }
+        else
+        {
+            // __nth_element<_Compare>(__i+1, __nth, __last, __comp);
+            __first = ++__i;
+        }
+    }
+}
+
+template <class _RandomAccessIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    __nth_element<_Comp_ref>(__first, __nth, __last, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    __nth_element<_Comp_ref>(__first, __nth, __last, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _RandomAccessIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last)
+{
+    _VSTD::nth_element(__first, __nth, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
+}
+
+// includes
+
+template <class _Compare, class _InputIterator1, class _InputIterator2>
+bool
+__includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
+           _Compare __comp)
+{
+    for (; __first2 != __last2; ++__first1)
+    {
+        if (__first1 == __last1 || __comp(*__first2, *__first1))
+            return false;
+        if (!__comp(*__first1, *__first2))
+            ++__first2;
+    }
+    return true;
+}
+
+template <class _InputIterator1, class _InputIterator2, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
+         _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    return __includes<_Comp_ref>(__first1, __last1, __first2, __last2, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    return __includes<_Comp_ref>(__first1, __last1, __first2, __last2, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _InputIterator1, class _InputIterator2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2)
+{
+    return _VSTD::includes(__first1, __last1, __first2, __last2,
+                          __less<typename iterator_traits<_InputIterator1>::value_type,
+                                 typename iterator_traits<_InputIterator2>::value_type>());
+}
+
+// set_union
+
+template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
+_OutputIterator
+__set_union(_InputIterator1 __first1, _InputIterator1 __last1,
+            _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
+{
+    for (; __first1 != __last1; ++__result)
+    {
+        if (__first2 == __last2)
+            return _VSTD::copy(__first1, __last1, __result);
+        if (__comp(*__first2, *__first1))
+        {
+            *__result = *__first2;
+            ++__first2;
+        }
+        else
+        {
+            *__result = *__first1;
+            if (!__comp(*__first1, *__first2))
+                ++__first2;
+            ++__first1;
+        }
+    }
+    return _VSTD::copy(__first2, __last2, __result);
+}
+
+template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+set_union(_InputIterator1 __first1, _InputIterator1 __last1,
+          _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    return __set_union<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    return __set_union<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+set_union(_InputIterator1 __first1, _InputIterator1 __last1,
+          _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
+{
+    return _VSTD::set_union(__first1, __last1, __first2, __last2, __result,
+                          __less<typename iterator_traits<_InputIterator1>::value_type,
+                                 typename iterator_traits<_InputIterator2>::value_type>());
+}
+
+// set_intersection
+
+template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
+_OutputIterator
+__set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
+                   _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
+{
+    while (__first1 != __last1 && __first2 != __last2)
+    {
+        if (__comp(*__first1, *__first2))
+            ++__first1;
+        else
+        {
+            if (!__comp(*__first2, *__first1))
+            {
+                *__result = *__first1;
+                ++__result;
+                ++__first1;
+            }
+            ++__first2;
+        }
+    }
+    return __result;
+}
+
+template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
+                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    return __set_intersection<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    return __set_intersection<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
+                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
+{
+    return _VSTD::set_intersection(__first1, __last1, __first2, __last2, __result,
+                                  __less<typename iterator_traits<_InputIterator1>::value_type,
+                                         typename iterator_traits<_InputIterator2>::value_type>());
+}
+
+// set_difference
+
+template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
+_OutputIterator
+__set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
+                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
+{
+    while (__first1 != __last1)
+    {
+        if (__first2 == __last2)
+            return _VSTD::copy(__first1, __last1, __result);
+        if (__comp(*__first1, *__first2))
+        {
+            *__result = *__first1;
+            ++__result;
+            ++__first1;
+        }
+        else
+        {
+            if (!__comp(*__first2, *__first1))
+                ++__first1;
+            ++__first2;
+        }
+    }
+    return __result;
+}
+
+template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
+               _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    return __set_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    return __set_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
+               _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
+{
+    return _VSTD::set_difference(__first1, __last1, __first2, __last2, __result,
+                                __less<typename iterator_traits<_InputIterator1>::value_type,
+                                       typename iterator_traits<_InputIterator2>::value_type>());
+}
+
+// set_symmetric_difference
+
+template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
+_OutputIterator
+__set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
+                           _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
+{
+    while (__first1 != __last1)
+    {
+        if (__first2 == __last2)
+            return _VSTD::copy(__first1, __last1, __result);
+        if (__comp(*__first1, *__first2))
+        {
+            *__result = *__first1;
+            ++__result;
+            ++__first1;
+        }
+        else
+        {
+            if (__comp(*__first2, *__first1))
+            {
+                *__result = *__first2;
+                ++__result;
+            }
+            else
+                ++__first1;
+            ++__first2;
+        }
+    }
+    return _VSTD::copy(__first2, __last2, __result);
+}
+
+template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
+                         _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    return __set_symmetric_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    return __set_symmetric_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
+                         _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
+{
+    return _VSTD::set_symmetric_difference(__first1, __last1, __first2, __last2, __result,
+                                          __less<typename iterator_traits<_InputIterator1>::value_type,
+                                                 typename iterator_traits<_InputIterator2>::value_type>());
+}
+
+// lexicographical_compare
+
+template <class _Compare, class _InputIterator1, class _InputIterator2>
+bool
+__lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
+                          _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
+{
+    for (; __first2 != __last2; ++__first1, (void) ++__first2)
+    {
+        if (__first1 == __last1 || __comp(*__first1, *__first2))
+            return true;
+        if (__comp(*__first2, *__first1))
+            return false;
+    }
+    return false;
+}
+
+template <class _InputIterator1, class _InputIterator2, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
+                        _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    return __lexicographical_compare<_Comp_ref>(__first1, __last1, __first2, __last2, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    return __lexicographical_compare<_Comp_ref>(__first1, __last1, __first2, __last2, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _InputIterator1, class _InputIterator2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
+                        _InputIterator2 __first2, _InputIterator2 __last2)
+{
+    return _VSTD::lexicographical_compare(__first1, __last1, __first2, __last2,
+                                         __less<typename iterator_traits<_InputIterator1>::value_type,
+                                                typename iterator_traits<_InputIterator2>::value_type>());
+}
+
+// next_permutation
+
+template <class _Compare, class _BidirectionalIterator>
+bool
+__next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
+{
+    _BidirectionalIterator __i = __last;
+    if (__first == __last || __first == --__i)
+        return false;
+    while (true)
+    {
+        _BidirectionalIterator __ip1 = __i;
+        if (__comp(*--__i, *__ip1))
+        {
+            _BidirectionalIterator __j = __last;
+            while (!__comp(*__i, *--__j))
+                ;
+            swap(*__i, *__j);
+            _VSTD::reverse(__ip1, __last);
+            return true;
+        }
+        if (__i == __first)
+        {
+            _VSTD::reverse(__first, __last);
+            return false;
+        }
+    }
+}
+
+template <class _BidirectionalIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    return __next_permutation<_Comp_ref>(__first, __last, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    return __next_permutation<_Comp_ref>(__first, __last, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _BidirectionalIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last)
+{
+    return _VSTD::next_permutation(__first, __last,
+                                  __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
+}
+
+// prev_permutation
+
+template <class _Compare, class _BidirectionalIterator>
+bool
+__prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
+{
+    _BidirectionalIterator __i = __last;
+    if (__first == __last || __first == --__i)
+        return false;
+    while (true)
+    {
+        _BidirectionalIterator __ip1 = __i;
+        if (__comp(*__ip1, *--__i))
+        {
+            _BidirectionalIterator __j = __last;
+            while (!__comp(*--__j, *__i))
+                ;
+            swap(*__i, *__j);
+            _VSTD::reverse(__ip1, __last);
+            return true;
+        }
+        if (__i == __first)
+        {
+            _VSTD::reverse(__first, __last);
+            return false;
+        }
+    }
+}
+
+template <class _BidirectionalIterator, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
+{
+#ifdef _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
+    __debug_less<_Compare> __c(__comp);
+    return __prev_permutation<_Comp_ref>(__first, __last, __c);
+#else  // _LIBCPP_DEBUG
+    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
+    return __prev_permutation<_Comp_ref>(__first, __last, __comp);
+#endif  // _LIBCPP_DEBUG
+}
+
+template <class _BidirectionalIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last)
+{
+    return _VSTD::prev_permutation(__first, __last,
+                                  __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value,
+    _Tp
+>::type
+__rotate_left(_Tp __t, _Tp __n = 1)
+{
+    const unsigned __bits = static_cast<unsigned>(sizeof(_Tp) * __CHAR_BIT__ - 1);
+    __n &= __bits;
+    return static_cast<_Tp>((__t << __n) | (static_cast<typename make_unsigned<_Tp>::type>(__t) >> (__bits - __n)));
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value,
+    _Tp
+>::type
+__rotate_right(_Tp __t, _Tp __n = 1)
+{
+    const unsigned __bits = static_cast<unsigned>(sizeof(_Tp) * __CHAR_BIT__ - 1);
+    __n &= __bits;
+    return static_cast<_Tp>((__t << (__bits - __n)) | (static_cast<typename make_unsigned<_Tp>::type>(__t) >> __n));
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_ALGORITHM

diff --git a/libcxx/include/array b/libcxx/include/array
new file mode 100644
index 0000000..2e02a43
--- /dev/null
+++ b/libcxx/include/array

@@ -0,0 +1,331 @@
+// -*- C++ -*-
+//===---------------------------- array -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_ARRAY
+#define _LIBCPP_ARRAY
+
+/*
+    array synopsis
+
+namespace std
+{
+template <class T, size_t N >
+struct array
+{
+    // types:
+    typedef T & reference;
+    typedef const T & const_reference;
+    typedef implementation defined iterator;
+    typedef implementation defined const_iterator;
+    typedef size_t size_type;
+    typedef ptrdiff_t difference_type;
+    typedef T value_type;
+    typedef T* pointer;
+    typedef const T* const_pointer;
+    typedef std::reverse_iterator<iterator> reverse_iterator;
+    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
+
+    // No explicit construct/copy/destroy for aggregate type
+    void fill(const T& u);
+    void swap(array& a) noexcept(noexcept(swap(declval<T&>(), declval<T&>())));
+
+    // iterators:
+    iterator begin() noexcept;
+    const_iterator begin() const noexcept;
+    iterator end() noexcept;
+    const_iterator end() const noexcept;
+
+    reverse_iterator rbegin() noexcept;
+    const_reverse_iterator rbegin() const noexcept;
+    reverse_iterator rend() noexcept;
+    const_reverse_iterator rend() const noexcept;
+
+    const_iterator cbegin() const noexcept;
+    const_iterator cend() const noexcept;
+    const_reverse_iterator crbegin() const noexcept;
+    const_reverse_iterator crend() const noexcept;
+
+    // capacity:
+    constexpr size_type size() const noexcept;
+    constexpr size_type max_size() const noexcept;
+    constexpr bool empty() const noexcept;
+
+    // element access:
+    reference operator[](size_type n);
+    const_reference operator[](size_type n) const; // constexpr in C++14
+    const_reference at(size_type n) const; // constexpr in C++14
+    reference at(size_type n);
+
+    reference front();
+    const_reference front() const; // constexpr in C++14
+    reference back();
+    const_reference back() const; // constexpr in C++14
+
+    T* data() noexcept;
+    const T* data() const noexcept;
+};
+
+template <class T, size_t N>
+  bool operator==(const array<T,N>& x, const array<T,N>& y);
+template <class T, size_t N>
+  bool operator!=(const array<T,N>& x, const array<T,N>& y);
+template <class T, size_t N>
+  bool operator<(const array<T,N>& x, const array<T,N>& y);
+template <class T, size_t N>
+  bool operator>(const array<T,N>& x, const array<T,N>& y);
+template <class T, size_t N>
+  bool operator<=(const array<T,N>& x, const array<T,N>& y);
+template <class T, size_t N>
+  bool operator>=(const array<T,N>& x, const array<T,N>& y);
+
+template <class T, size_t N >
+  void swap(array<T,N>& x, array<T,N>& y) noexcept(noexcept(x.swap(y)));
+
+template <class T> class tuple_size;
+template <int I, class T> class tuple_element;
+template <class T, size_t N> struct tuple_size<array<T, N>>;
+template <int I, class T, size_t N> struct tuple_element<I, array<T, N>>;
+template <int I, class T, size_t N> T& get(array<T, N>&) noexcept; // constexpr in C++14
+template <int I, class T, size_t N> const T& get(const array<T, N>&) noexcept; // constexpr in C++14
+template <int I, class T, size_t N> T&& get(array<T, N>&&) noexcept; // constexpr in C++14
+
+}  // std
+
+*/
+
+#include <__config>
+#include <__tuple>
+#include <type_traits>
+#include <utility>
+#include <iterator>
+#include <algorithm>
+#include <stdexcept>
+#if defined(_LIBCPP_NO_EXCEPTIONS)
+    #include <cassert>
+#endif
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp, size_t _Size>
+struct _LIBCPP_TYPE_VIS_ONLY array
+{
+    // types:
+    typedef array __self;
+    typedef _Tp                                   value_type;
+    typedef value_type&                           reference;
+    typedef const value_type&                     const_reference;
+    typedef value_type*                           iterator;
+    typedef const value_type*                     const_iterator;
+    typedef value_type*                           pointer;
+    typedef const value_type*                     const_pointer;
+    typedef size_t                                size_type;
+    typedef ptrdiff_t                             difference_type;
+    typedef std::reverse_iterator<iterator>       reverse_iterator;
+    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
+
+    value_type __elems_[_Size > 0 ? _Size : 1];
+
+    // No explicit construct/copy/destroy for aggregate type
+    _LIBCPP_INLINE_VISIBILITY void fill(const value_type& __u)
+        {_VSTD::fill_n(__elems_, _Size, __u);}
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(array& __a) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value)
+        {_VSTD::swap_ranges(__elems_, __elems_ + _Size, __a.__elems_);}
+
+    // iterators:
+    _LIBCPP_INLINE_VISIBILITY
+    iterator begin() _NOEXCEPT {return iterator(__elems_);}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator begin() const _NOEXCEPT {return const_iterator(__elems_);}
+    _LIBCPP_INLINE_VISIBILITY
+    iterator end() _NOEXCEPT {return iterator(__elems_ + _Size);}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator end() const _NOEXCEPT {return const_iterator(__elems_ + _Size);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
+    _LIBCPP_INLINE_VISIBILITY
+    reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator cbegin() const _NOEXCEPT {return begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator cend() const _NOEXCEPT {return end();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
+
+    // capacity:
+    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return _Size;}
+    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return _Size;}
+    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return _Size == 0;}
+
+    // element access:
+    _LIBCPP_INLINE_VISIBILITY reference operator[](size_type __n)             {return __elems_[__n];}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference operator[](size_type __n) const {return __elems_[__n];}
+    reference at(size_type __n);
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference at(size_type __n) const;
+
+    _LIBCPP_INLINE_VISIBILITY reference front()             {return __elems_[0];}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference front() const {return __elems_[0];}
+    _LIBCPP_INLINE_VISIBILITY reference back()              {return __elems_[_Size > 0 ? _Size-1 : 0];}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference back() const  {return __elems_[_Size > 0 ? _Size-1 : 0];}
+
+    _LIBCPP_INLINE_VISIBILITY
+    value_type* data() _NOEXCEPT {return __elems_;}
+    _LIBCPP_INLINE_VISIBILITY
+    const value_type* data() const _NOEXCEPT {return __elems_;}
+};
+
+template <class _Tp, size_t _Size>
+typename array<_Tp, _Size>::reference
+array<_Tp, _Size>::at(size_type __n)
+{
+    if (__n >= _Size)
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        throw out_of_range("array::at");
+#else
+        assert(!"array::at out_of_range");
+#endif
+    return __elems_[__n];
+}
+
+template <class _Tp, size_t _Size>
+_LIBCPP_CONSTEXPR_AFTER_CXX11
+typename array<_Tp, _Size>::const_reference
+array<_Tp, _Size>::at(size_type __n) const
+{
+    if (__n >= _Size)
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        throw out_of_range("array::at");
+#else
+        assert(!"array::at out_of_range");
+#endif
+    return __elems_[__n];
+}
+
+template <class _Tp, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
+{
+    return _VSTD::equal(__x.__elems_, __x.__elems_ + _Size, __y.__elems_);
+}
+
+template <class _Tp, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
+{
+    return !(__x == __y);
+}
+
+template <class _Tp, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
+{
+    return _VSTD::lexicographical_compare(__x.__elems_, __x.__elems_ + _Size, __y.__elems_, __y.__elems_ + _Size);
+}
+
+template <class _Tp, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
+{
+    return __y < __x;
+}
+
+template <class _Tp, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
+{
+    return !(__y < __x);
+}
+
+template <class _Tp, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
+{
+    return !(__x < __y);
+}
+
+template <class _Tp, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    __is_swappable<_Tp>::value,
+    void
+>::type
+swap(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
+                                  _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value)
+{
+    __x.swap(__y);
+}
+
+template <class _Tp, size_t _Size>
+class _LIBCPP_TYPE_VIS_ONLY tuple_size<array<_Tp, _Size> >
+    : public integral_constant<size_t, _Size> {};
+
+template <size_t _Ip, class _Tp, size_t _Size>
+class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, array<_Tp, _Size> >
+{
+public:
+    typedef _Tp type;
+};
+
+template <size_t _Ip, class _Tp, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_Tp&
+get(array<_Tp, _Size>& __a) _NOEXCEPT
+{
+    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array)");
+    return __a.__elems_[_Ip];
+}
+
+template <size_t _Ip, class _Tp, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const _Tp&
+get(const array<_Tp, _Size>& __a) _NOEXCEPT
+{
+    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array)");
+    return __a.__elems_[_Ip];
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <size_t _Ip, class _Tp, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_Tp&&
+get(array<_Tp, _Size>&& __a) _NOEXCEPT
+{
+    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array &&)");
+    return _VSTD::move(__a.__elems_[_Ip]);
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_ARRAY

diff --git a/libcxx/include/atomic b/libcxx/include/atomic
new file mode 100644
index 0000000..97a998d
--- /dev/null
+++ b/libcxx/include/atomic

@@ -0,0 +1,1801 @@
+// -*- C++ -*-
+//===--------------------------- atomic -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_ATOMIC
+#define _LIBCPP_ATOMIC
+
+/*
+    atomic synopsis
+
+namespace std
+{
+
+// order and consistency
+
+typedef enum memory_order
+{
+    memory_order_relaxed,
+    memory_order_consume,  // load-consume
+    memory_order_acquire,  // load-acquire
+    memory_order_release,  // store-release
+    memory_order_acq_rel,  // store-release load-acquire
+    memory_order_seq_cst   // store-release load-acquire
+} memory_order;
+
+template <class T> T kill_dependency(T y) noexcept;
+
+// lock-free property
+
+#define ATOMIC_BOOL_LOCK_FREE unspecified
+#define ATOMIC_CHAR_LOCK_FREE unspecified
+#define ATOMIC_CHAR16_T_LOCK_FREE unspecified
+#define ATOMIC_CHAR32_T_LOCK_FREE unspecified
+#define ATOMIC_WCHAR_T_LOCK_FREE unspecified
+#define ATOMIC_SHORT_LOCK_FREE unspecified
+#define ATOMIC_INT_LOCK_FREE unspecified
+#define ATOMIC_LONG_LOCK_FREE unspecified
+#define ATOMIC_LLONG_LOCK_FREE unspecified
+#define ATOMIC_POINTER_LOCK_FREE unspecified
+
+// flag type and operations
+
+typedef struct atomic_flag
+{
+    bool test_and_set(memory_order m = memory_order_seq_cst) volatile noexcept;
+    bool test_and_set(memory_order m = memory_order_seq_cst) noexcept;
+    void clear(memory_order m = memory_order_seq_cst) volatile noexcept;
+    void clear(memory_order m = memory_order_seq_cst) noexcept;
+    atomic_flag()  noexcept = default;
+    atomic_flag(const atomic_flag&) = delete;
+    atomic_flag& operator=(const atomic_flag&) = delete;
+    atomic_flag& operator=(const atomic_flag&) volatile = delete;
+} atomic_flag;
+
+bool
+    atomic_flag_test_and_set(volatile atomic_flag* obj) noexcept;
+
+bool
+    atomic_flag_test_and_set(atomic_flag* obj) noexcept;
+
+bool
+    atomic_flag_test_and_set_explicit(volatile atomic_flag* obj,
+                                      memory_order m) noexcept;
+
+bool
+    atomic_flag_test_and_set_explicit(atomic_flag* obj, memory_order m) noexcept;
+
+void
+    atomic_flag_clear(volatile atomic_flag* obj) noexcept;
+
+void
+    atomic_flag_clear(atomic_flag* obj) noexcept;
+
+void
+    atomic_flag_clear_explicit(volatile atomic_flag* obj, memory_order m) noexcept;
+
+void
+    atomic_flag_clear_explicit(atomic_flag* obj, memory_order m) noexcept;
+
+#define ATOMIC_FLAG_INIT see below
+#define ATOMIC_VAR_INIT(value) see below
+
+template <class T>
+struct atomic
+{
+    bool is_lock_free() const volatile noexcept;
+    bool is_lock_free() const noexcept;
+    void store(T desr, memory_order m = memory_order_seq_cst) volatile noexcept;
+    void store(T desr, memory_order m = memory_order_seq_cst) noexcept;
+    T load(memory_order m = memory_order_seq_cst) const volatile noexcept;
+    T load(memory_order m = memory_order_seq_cst) const noexcept;
+    operator T() const volatile noexcept;
+    operator T() const noexcept;
+    T exchange(T desr, memory_order m = memory_order_seq_cst) volatile noexcept;
+    T exchange(T desr, memory_order m = memory_order_seq_cst) noexcept;
+    bool compare_exchange_weak(T& expc, T desr,
+                               memory_order s, memory_order f) volatile noexcept;
+    bool compare_exchange_weak(T& expc, T desr, memory_order s, memory_order f) noexcept;
+    bool compare_exchange_strong(T& expc, T desr,
+                                 memory_order s, memory_order f) volatile noexcept;
+    bool compare_exchange_strong(T& expc, T desr,
+                                 memory_order s, memory_order f) noexcept;
+    bool compare_exchange_weak(T& expc, T desr,
+                               memory_order m = memory_order_seq_cst) volatile noexcept;
+    bool compare_exchange_weak(T& expc, T desr,
+                               memory_order m = memory_order_seq_cst) noexcept;
+    bool compare_exchange_strong(T& expc, T desr,
+                                memory_order m = memory_order_seq_cst) volatile noexcept;
+    bool compare_exchange_strong(T& expc, T desr,
+                                 memory_order m = memory_order_seq_cst) noexcept;
+
+    atomic() noexcept = default;
+    constexpr atomic(T desr) noexcept;
+    atomic(const atomic&) = delete;
+    atomic& operator=(const atomic&) = delete;
+    atomic& operator=(const atomic&) volatile = delete;
+    T operator=(T) volatile noexcept;
+    T operator=(T) noexcept;
+};
+
+template <>
+struct atomic<integral>
+{
+    bool is_lock_free() const volatile noexcept;
+    bool is_lock_free() const noexcept;
+    void store(integral desr, memory_order m = memory_order_seq_cst) volatile noexcept;
+    void store(integral desr, memory_order m = memory_order_seq_cst) noexcept;
+    integral load(memory_order m = memory_order_seq_cst) const volatile noexcept;
+    integral load(memory_order m = memory_order_seq_cst) const noexcept;
+    operator integral() const volatile noexcept;
+    operator integral() const noexcept;
+    integral exchange(integral desr,
+                      memory_order m = memory_order_seq_cst) volatile noexcept;
+    integral exchange(integral desr, memory_order m = memory_order_seq_cst) noexcept;
+    bool compare_exchange_weak(integral& expc, integral desr,
+                               memory_order s, memory_order f) volatile noexcept;
+    bool compare_exchange_weak(integral& expc, integral desr,
+                               memory_order s, memory_order f) noexcept;
+    bool compare_exchange_strong(integral& expc, integral desr,
+                                 memory_order s, memory_order f) volatile noexcept;
+    bool compare_exchange_strong(integral& expc, integral desr,
+                                 memory_order s, memory_order f) noexcept;
+    bool compare_exchange_weak(integral& expc, integral desr,
+                               memory_order m = memory_order_seq_cst) volatile noexcept;
+    bool compare_exchange_weak(integral& expc, integral desr,
+                               memory_order m = memory_order_seq_cst) noexcept;
+    bool compare_exchange_strong(integral& expc, integral desr,
+                                memory_order m = memory_order_seq_cst) volatile noexcept;
+    bool compare_exchange_strong(integral& expc, integral desr,
+                                 memory_order m = memory_order_seq_cst) noexcept;
+
+    integral
+        fetch_add(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
+    integral fetch_add(integral op, memory_order m = memory_order_seq_cst) noexcept;
+    integral
+        fetch_sub(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
+    integral fetch_sub(integral op, memory_order m = memory_order_seq_cst) noexcept;
+    integral
+        fetch_and(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
+    integral fetch_and(integral op, memory_order m = memory_order_seq_cst) noexcept;
+    integral
+        fetch_or(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
+    integral fetch_or(integral op, memory_order m = memory_order_seq_cst) noexcept;
+    integral
+        fetch_xor(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
+    integral fetch_xor(integral op, memory_order m = memory_order_seq_cst) noexcept;
+
+    atomic() noexcept = default;
+    constexpr atomic(integral desr) noexcept;
+    atomic(const atomic&) = delete;
+    atomic& operator=(const atomic&) = delete;
+    atomic& operator=(const atomic&) volatile = delete;
+    integral operator=(integral desr) volatile noexcept;
+    integral operator=(integral desr) noexcept;
+
+    integral operator++(int) volatile noexcept;
+    integral operator++(int) noexcept;
+    integral operator--(int) volatile noexcept;
+    integral operator--(int) noexcept;
+    integral operator++() volatile noexcept;
+    integral operator++() noexcept;
+    integral operator--() volatile noexcept;
+    integral operator--() noexcept;
+    integral operator+=(integral op) volatile noexcept;
+    integral operator+=(integral op) noexcept;
+    integral operator-=(integral op) volatile noexcept;
+    integral operator-=(integral op) noexcept;
+    integral operator&=(integral op) volatile noexcept;
+    integral operator&=(integral op) noexcept;
+    integral operator|=(integral op) volatile noexcept;
+    integral operator|=(integral op) noexcept;
+    integral operator^=(integral op) volatile noexcept;
+    integral operator^=(integral op) noexcept;
+};
+
+template <class T>
+struct atomic<T*>
+{
+    bool is_lock_free() const volatile noexcept;
+    bool is_lock_free() const noexcept;
+    void store(T* desr, memory_order m = memory_order_seq_cst) volatile noexcept;
+    void store(T* desr, memory_order m = memory_order_seq_cst) noexcept;
+    T* load(memory_order m = memory_order_seq_cst) const volatile noexcept;
+    T* load(memory_order m = memory_order_seq_cst) const noexcept;
+    operator T*() const volatile noexcept;
+    operator T*() const noexcept;
+    T* exchange(T* desr, memory_order m = memory_order_seq_cst) volatile noexcept;
+    T* exchange(T* desr, memory_order m = memory_order_seq_cst) noexcept;
+    bool compare_exchange_weak(T*& expc, T* desr,
+                               memory_order s, memory_order f) volatile noexcept;
+    bool compare_exchange_weak(T*& expc, T* desr,
+                               memory_order s, memory_order f) noexcept;
+    bool compare_exchange_strong(T*& expc, T* desr,
+                                 memory_order s, memory_order f) volatile noexcept;
+    bool compare_exchange_strong(T*& expc, T* desr,
+                                 memory_order s, memory_order f) noexcept;
+    bool compare_exchange_weak(T*& expc, T* desr,
+                               memory_order m = memory_order_seq_cst) volatile noexcept;
+    bool compare_exchange_weak(T*& expc, T* desr,
+                               memory_order m = memory_order_seq_cst) noexcept;
+    bool compare_exchange_strong(T*& expc, T* desr,
+                                memory_order m = memory_order_seq_cst) volatile noexcept;
+    bool compare_exchange_strong(T*& expc, T* desr,
+                                 memory_order m = memory_order_seq_cst) noexcept;
+    T* fetch_add(ptrdiff_t op, memory_order m = memory_order_seq_cst) volatile noexcept;
+    T* fetch_add(ptrdiff_t op, memory_order m = memory_order_seq_cst) noexcept;
+    T* fetch_sub(ptrdiff_t op, memory_order m = memory_order_seq_cst) volatile noexcept;
+    T* fetch_sub(ptrdiff_t op, memory_order m = memory_order_seq_cst) noexcept;
+
+    atomic() noexcept = default;
+    constexpr atomic(T* desr) noexcept;
+    atomic(const atomic&) = delete;
+    atomic& operator=(const atomic&) = delete;
+    atomic& operator=(const atomic&) volatile = delete;
+
+    T* operator=(T*) volatile noexcept;
+    T* operator=(T*) noexcept;
+    T* operator++(int) volatile noexcept;
+    T* operator++(int) noexcept;
+    T* operator--(int) volatile noexcept;
+    T* operator--(int) noexcept;
+    T* operator++() volatile noexcept;
+    T* operator++() noexcept;
+    T* operator--() volatile noexcept;
+    T* operator--() noexcept;
+    T* operator+=(ptrdiff_t op) volatile noexcept;
+    T* operator+=(ptrdiff_t op) noexcept;
+    T* operator-=(ptrdiff_t op) volatile noexcept;
+    T* operator-=(ptrdiff_t op) noexcept;
+};
+
+
+template <class T>
+    bool
+    atomic_is_lock_free(const volatile atomic<T>* obj) noexcept;
+
+template <class T>
+    bool
+    atomic_is_lock_free(const atomic<T>* obj) noexcept;
+
+template <class T>
+    void
+    atomic_init(volatile atomic<T>* obj, T desr) noexcept;
+
+template <class T>
+    void
+    atomic_init(atomic<T>* obj, T desr) noexcept;
+
+template <class T>
+    void
+    atomic_store(volatile atomic<T>* obj, T desr) noexcept;
+
+template <class T>
+    void
+    atomic_store(atomic<T>* obj, T desr) noexcept;
+
+template <class T>
+    void
+    atomic_store_explicit(volatile atomic<T>* obj, T desr, memory_order m) noexcept;
+
+template <class T>
+    void
+    atomic_store_explicit(atomic<T>* obj, T desr, memory_order m) noexcept;
+
+template <class T>
+    T
+    atomic_load(const volatile atomic<T>* obj) noexcept;
+
+template <class T>
+    T
+    atomic_load(const atomic<T>* obj) noexcept;
+
+template <class T>
+    T
+    atomic_load_explicit(const volatile atomic<T>* obj, memory_order m) noexcept;
+
+template <class T>
+    T
+    atomic_load_explicit(const atomic<T>* obj, memory_order m) noexcept;
+
+template <class T>
+    T
+    atomic_exchange(volatile atomic<T>* obj, T desr) noexcept;
+
+template <class T>
+    T
+    atomic_exchange(atomic<T>* obj, T desr) noexcept;
+
+template <class T>
+    T
+    atomic_exchange_explicit(volatile atomic<T>* obj, T desr, memory_order m) noexcept;
+
+template <class T>
+    T
+    atomic_exchange_explicit(atomic<T>* obj, T desr, memory_order m) noexcept;
+
+template <class T>
+    bool
+    atomic_compare_exchange_weak(volatile atomic<T>* obj, T* expc, T desr) noexcept;
+
+template <class T>
+    bool
+    atomic_compare_exchange_weak(atomic<T>* obj, T* expc, T desr) noexcept;
+
+template <class T>
+    bool
+    atomic_compare_exchange_strong(volatile atomic<T>* obj, T* expc, T desr) noexcept;
+
+template <class T>
+    bool
+    atomic_compare_exchange_strong(atomic<T>* obj, T* expc, T desr) noexcept;
+
+template <class T>
+    bool
+    atomic_compare_exchange_weak_explicit(volatile atomic<T>* obj, T* expc,
+                                          T desr,
+                                          memory_order s, memory_order f) noexcept;
+
+template <class T>
+    bool
+    atomic_compare_exchange_weak_explicit(atomic<T>* obj, T* expc, T desr,
+                                          memory_order s, memory_order f) noexcept;
+
+template <class T>
+    bool
+    atomic_compare_exchange_strong_explicit(volatile atomic<T>* obj,
+                                            T* expc, T desr,
+                                            memory_order s, memory_order f) noexcept;
+
+template <class T>
+    bool
+    atomic_compare_exchange_strong_explicit(atomic<T>* obj, T* expc,
+                                            T desr,
+                                            memory_order s, memory_order f) noexcept;
+
+template <class Integral>
+    Integral
+    atomic_fetch_add(volatile atomic<Integral>* obj, Integral op) noexcept;
+
+template <class Integral>
+    Integral
+    atomic_fetch_add(atomic<Integral>* obj, Integral op) noexcept;
+
+template <class Integral>
+    Integral
+    atomic_fetch_add_explicit(volatile atomic<Integral>* obj, Integral op,
+                              memory_order m) noexcept;
+template <class Integral>
+    Integral
+    atomic_fetch_add_explicit(atomic<Integral>* obj, Integral op,
+                              memory_order m) noexcept;
+template <class Integral>
+    Integral
+    atomic_fetch_sub(volatile atomic<Integral>* obj, Integral op) noexcept;
+
+template <class Integral>
+    Integral
+    atomic_fetch_sub(atomic<Integral>* obj, Integral op) noexcept;
+
+template <class Integral>
+    Integral
+    atomic_fetch_sub_explicit(volatile atomic<Integral>* obj, Integral op,
+                              memory_order m) noexcept;
+template <class Integral>
+    Integral
+    atomic_fetch_sub_explicit(atomic<Integral>* obj, Integral op,
+                              memory_order m) noexcept;
+template <class Integral>
+    Integral
+    atomic_fetch_and(volatile atomic<Integral>* obj, Integral op) noexcept;
+
+template <class Integral>
+    Integral
+    atomic_fetch_and(atomic<Integral>* obj, Integral op) noexcept;
+
+template <class Integral>
+    Integral
+    atomic_fetch_and_explicit(volatile atomic<Integral>* obj, Integral op,
+                              memory_order m) noexcept;
+template <class Integral>
+    Integral
+    atomic_fetch_and_explicit(atomic<Integral>* obj, Integral op,
+                              memory_order m) noexcept;
+template <class Integral>
+    Integral
+    atomic_fetch_or(volatile atomic<Integral>* obj, Integral op) noexcept;
+
+template <class Integral>
+    Integral
+    atomic_fetch_or(atomic<Integral>* obj, Integral op) noexcept;
+
+template <class Integral>
+    Integral
+    atomic_fetch_or_explicit(volatile atomic<Integral>* obj, Integral op,
+                             memory_order m) noexcept;
+template <class Integral>
+    Integral
+    atomic_fetch_or_explicit(atomic<Integral>* obj, Integral op,
+                             memory_order m) noexcept;
+template <class Integral>
+    Integral
+    atomic_fetch_xor(volatile atomic<Integral>* obj, Integral op) noexcept;
+
+template <class Integral>
+    Integral
+    atomic_fetch_xor(atomic<Integral>* obj, Integral op) noexcept;
+
+template <class Integral>
+    Integral
+    atomic_fetch_xor_explicit(volatile atomic<Integral>* obj, Integral op,
+                              memory_order m) noexcept;
+template <class Integral>
+    Integral
+    atomic_fetch_xor_explicit(atomic<Integral>* obj, Integral op,
+                              memory_order m) noexcept;
+
+template <class T>
+    T*
+    atomic_fetch_add(volatile atomic<T*>* obj, ptrdiff_t op) noexcept;
+
+template <class T>
+    T*
+    atomic_fetch_add(atomic<T*>* obj, ptrdiff_t op) noexcept;
+
+template <class T>
+    T*
+    atomic_fetch_add_explicit(volatile atomic<T*>* obj, ptrdiff_t op,
+                              memory_order m) noexcept;
+template <class T>
+    T*
+    atomic_fetch_add_explicit(atomic<T*>* obj, ptrdiff_t op, memory_order m) noexcept;
+
+template <class T>
+    T*
+    atomic_fetch_sub(volatile atomic<T*>* obj, ptrdiff_t op) noexcept;
+
+template <class T>
+    T*
+    atomic_fetch_sub(atomic<T*>* obj, ptrdiff_t op) noexcept;
+
+template <class T>
+    T*
+    atomic_fetch_sub_explicit(volatile atomic<T*>* obj, ptrdiff_t op,
+                              memory_order m) noexcept;
+template <class T>
+    T*
+    atomic_fetch_sub_explicit(atomic<T*>* obj, ptrdiff_t op, memory_order m) noexcept;
+
+// Atomics for standard typedef types
+
+typedef atomic<bool>               atomic_bool;
+typedef atomic<char>               atomic_char;
+typedef atomic<signed char>        atomic_schar;
+typedef atomic<unsigned char>      atomic_uchar;
+typedef atomic<short>              atomic_short;
+typedef atomic<unsigned short>     atomic_ushort;
+typedef atomic<int>                atomic_int;
+typedef atomic<unsigned int>       atomic_uint;
+typedef atomic<long>               atomic_long;
+typedef atomic<unsigned long>      atomic_ulong;
+typedef atomic<long long>          atomic_llong;
+typedef atomic<unsigned long long> atomic_ullong;
+typedef atomic<char16_t>           atomic_char16_t;
+typedef atomic<char32_t>           atomic_char32_t;
+typedef atomic<wchar_t>            atomic_wchar_t;
+
+typedef atomic<int_least8_t>   atomic_int_least8_t;
+typedef atomic<uint_least8_t>  atomic_uint_least8_t;
+typedef atomic<int_least16_t>  atomic_int_least16_t;
+typedef atomic<uint_least16_t> atomic_uint_least16_t;
+typedef atomic<int_least32_t>  atomic_int_least32_t;
+typedef atomic<uint_least32_t> atomic_uint_least32_t;
+typedef atomic<int_least64_t>  atomic_int_least64_t;
+typedef atomic<uint_least64_t> atomic_uint_least64_t;
+
+typedef atomic<int_fast8_t>   atomic_int_fast8_t;
+typedef atomic<uint_fast8_t>  atomic_uint_fast8_t;
+typedef atomic<int_fast16_t>  atomic_int_fast16_t;
+typedef atomic<uint_fast16_t> atomic_uint_fast16_t;
+typedef atomic<int_fast32_t>  atomic_int_fast32_t;
+typedef atomic<uint_fast32_t> atomic_uint_fast32_t;
+typedef atomic<int_fast64_t>  atomic_int_fast64_t;
+typedef atomic<uint_fast64_t> atomic_uint_fast64_t;
+
+typedef atomic<intptr_t>  atomic_intptr_t;
+typedef atomic<uintptr_t> atomic_uintptr_t;
+typedef atomic<size_t>    atomic_size_t;
+typedef atomic<ptrdiff_t> atomic_ptrdiff_t;
+typedef atomic<intmax_t>  atomic_intmax_t;
+typedef atomic<uintmax_t> atomic_uintmax_t;
+
+// fences
+
+void atomic_thread_fence(memory_order m) noexcept;
+void atomic_signal_fence(memory_order m) noexcept;
+
+}  // std
+
+*/
+
+#include <__config>
+#include <cstddef>
+#include <cstdint>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#ifdef _LIBCPP_HAS_NO_THREADS
+#error <atomic> is not supported on this single threaded system
+#else // !_LIBCPP_HAS_NO_THREADS
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if !__has_feature(cxx_atomic) && _GNUC_VER < 407
+#error <atomic> is not implemented
+#else
+
+typedef enum memory_order
+{
+    memory_order_relaxed, memory_order_consume, memory_order_acquire,
+    memory_order_release, memory_order_acq_rel, memory_order_seq_cst
+} memory_order;
+
+#if _GNUC_VER >= 407
+namespace __gcc_atomic {
+template <typename _Tp>
+struct __gcc_atomic_t {
+  __gcc_atomic_t() _NOEXCEPT {}
+  _LIBCPP_CONSTEXPR explicit __gcc_atomic_t(_Tp value) _NOEXCEPT
+    : __a_value(value) {}
+  _Tp __a_value;
+};
+#define _Atomic(x) __gcc_atomic::__gcc_atomic_t<x>
+
+template <typename _Tp> _Tp __create();
+
+template <typename _Tp, typename _Td>
+typename enable_if<sizeof(_Tp()->__a_value = __create<_Td>()), char>::type
+    __test_atomic_assignable(int);
+template <typename _Tp, typename _Up>
+__two __test_atomic_assignable(...);
+
+template <typename _Tp, typename _Td>
+struct __can_assign {
+  static const bool value =
+      sizeof(__test_atomic_assignable<_Tp, _Td>(1)) == sizeof(char);
+};
+
+static inline constexpr int __to_gcc_order(memory_order __order) {
+  // Avoid switch statement to make this a constexpr.
+  return __order == memory_order_relaxed ? __ATOMIC_RELAXED:
+         (__order == memory_order_acquire ? __ATOMIC_ACQUIRE:
+          (__order == memory_order_release ? __ATOMIC_RELEASE:
+           (__order == memory_order_seq_cst ? __ATOMIC_SEQ_CST:
+            (__order == memory_order_acq_rel ? __ATOMIC_ACQ_REL:
+              __ATOMIC_CONSUME))));
+}
+
+static inline constexpr int __to_gcc_failure_order(memory_order __order) {
+  // Avoid switch statement to make this a constexpr.
+  return __order == memory_order_relaxed ? __ATOMIC_RELAXED:
+         (__order == memory_order_acquire ? __ATOMIC_ACQUIRE:
+          (__order == memory_order_release ? __ATOMIC_RELAXED:
+           (__order == memory_order_seq_cst ? __ATOMIC_SEQ_CST:
+            (__order == memory_order_acq_rel ? __ATOMIC_ACQUIRE:
+              __ATOMIC_CONSUME))));
+}
+
+} // namespace __gcc_atomic
+
+template <typename _Tp>
+static inline
+typename enable_if<
+    __gcc_atomic::__can_assign<volatile _Atomic(_Tp)*, _Tp>::value>::type
+__c11_atomic_init(volatile _Atomic(_Tp)* __a,  _Tp __val) {
+  __a->__a_value = __val;
+}
+
+template <typename _Tp>
+static inline
+typename enable_if<
+    !__gcc_atomic::__can_assign<volatile _Atomic(_Tp)*, _Tp>::value &&
+     __gcc_atomic::__can_assign<         _Atomic(_Tp)*, _Tp>::value>::type
+__c11_atomic_init(volatile _Atomic(_Tp)* __a,  _Tp __val) {
+  // [atomics.types.generic]p1 guarantees _Tp is trivially copyable. Because
+  // the default operator= in an object is not volatile, a byte-by-byte copy
+  // is required.
+  volatile char* to = reinterpret_cast<volatile char*>(&__a->__a_value);
+  volatile char* end = to + sizeof(_Tp);
+  char* from = reinterpret_cast<char*>(&__val);
+  while (to != end) {
+    *to++ = *from++;
+  }
+}
+
+template <typename _Tp>
+static inline void __c11_atomic_init(_Atomic(_Tp)* __a,  _Tp __val) {
+  __a->__a_value = __val;
+}
+
+static inline void __c11_atomic_thread_fence(memory_order __order) {
+  __atomic_thread_fence(__gcc_atomic::__to_gcc_order(__order));
+}
+
+static inline void __c11_atomic_signal_fence(memory_order __order) {
+  __atomic_signal_fence(__gcc_atomic::__to_gcc_order(__order));
+}
+
+template <typename _Tp>
+static inline void __c11_atomic_store(volatile _Atomic(_Tp)* __a,  _Tp __val,
+                                      memory_order __order) {
+  return __atomic_store(&__a->__a_value, &__val,
+                        __gcc_atomic::__to_gcc_order(__order));
+}
+
+template <typename _Tp>
+static inline void __c11_atomic_store(_Atomic(_Tp)* __a,  _Tp __val,
+                                      memory_order __order) {
+  __atomic_store(&__a->__a_value, &__val,
+                 __gcc_atomic::__to_gcc_order(__order));
+}
+
+template <typename _Tp>
+static inline _Tp __c11_atomic_load(volatile _Atomic(_Tp)* __a,
+                                    memory_order __order) {
+  _Tp __ret;
+  __atomic_load(&__a->__a_value, &__ret,
+                __gcc_atomic::__to_gcc_order(__order));
+  return __ret;
+}
+
+template <typename _Tp>
+static inline _Tp __c11_atomic_load(_Atomic(_Tp)* __a, memory_order __order) {
+  _Tp __ret;
+  __atomic_load(&__a->__a_value, &__ret,
+                __gcc_atomic::__to_gcc_order(__order));
+  return __ret;
+}
+
+template <typename _Tp>
+static inline _Tp __c11_atomic_exchange(volatile _Atomic(_Tp)* __a,
+                                        _Tp __value, memory_order __order) {
+  _Tp __ret;
+  __atomic_exchange(&__a->__a_value, &__value, &__ret,
+                    __gcc_atomic::__to_gcc_order(__order));
+  return __ret;
+}
+
+template <typename _Tp>
+static inline _Tp __c11_atomic_exchange(_Atomic(_Tp)* __a, _Tp __value,
+                                        memory_order __order) {
+  _Tp __ret;
+  __atomic_exchange(&__a->__a_value, &__value, &__ret,
+                    __gcc_atomic::__to_gcc_order(__order));
+  return __ret;
+}
+
+template <typename _Tp>
+static inline bool __c11_atomic_compare_exchange_strong(
+    volatile _Atomic(_Tp)* __a, _Tp* __expected, _Tp __value,
+    memory_order __success, memory_order __failure) {
+  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
+                                   false,
+                                   __gcc_atomic::__to_gcc_order(__success),
+                                   __gcc_atomic::__to_gcc_failure_order(__failure));
+}
+
+template <typename _Tp>
+static inline bool __c11_atomic_compare_exchange_strong(
+    _Atomic(_Tp)* __a, _Tp* __expected, _Tp __value, memory_order __success,
+    memory_order __failure) {
+  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
+                                   false,
+                                   __gcc_atomic::__to_gcc_order(__success),
+                                   __gcc_atomic::__to_gcc_failure_order(__failure));
+}
+
+template <typename _Tp>
+static inline bool __c11_atomic_compare_exchange_weak(
+    volatile _Atomic(_Tp)* __a, _Tp* __expected, _Tp __value,
+    memory_order __success, memory_order __failure) {
+  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
+                                   true,
+                                   __gcc_atomic::__to_gcc_order(__success),
+                                   __gcc_atomic::__to_gcc_failure_order(__failure));
+}
+
+template <typename _Tp>
+static inline bool __c11_atomic_compare_exchange_weak(
+    _Atomic(_Tp)* __a, _Tp* __expected, _Tp __value, memory_order __success,
+    memory_order __failure) {
+  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
+                                   true,
+                                   __gcc_atomic::__to_gcc_order(__success),
+                                   __gcc_atomic::__to_gcc_failure_order(__failure));
+}
+
+template <typename _Tp>
+struct __skip_amt { enum {value = 1}; };
+
+template <typename _Tp>
+struct __skip_amt<_Tp*> { enum {value = sizeof(_Tp)}; };
+
+// FIXME: Haven't figured out what the spec says about using arrays with
+// atomic_fetch_add. Force a failure rather than creating bad behavior.
+template <typename _Tp>
+struct __skip_amt<_Tp[]> { };
+template <typename _Tp, int n>
+struct __skip_amt<_Tp[n]> { };
+
+template <typename _Tp, typename _Td>
+static inline _Tp __c11_atomic_fetch_add(volatile _Atomic(_Tp)* __a,
+                                         _Td __delta, memory_order __order) {
+  return __atomic_fetch_add(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
+                            __gcc_atomic::__to_gcc_order(__order));
+}
+
+template <typename _Tp, typename _Td>
+static inline _Tp __c11_atomic_fetch_add(_Atomic(_Tp)* __a, _Td __delta,
+                                         memory_order __order) {
+  return __atomic_fetch_add(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
+                            __gcc_atomic::__to_gcc_order(__order));
+}
+
+template <typename _Tp, typename _Td>
+static inline _Tp __c11_atomic_fetch_sub(volatile _Atomic(_Tp)* __a,
+                                         _Td __delta, memory_order __order) {
+  return __atomic_fetch_sub(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
+                            __gcc_atomic::__to_gcc_order(__order));
+}
+
+template <typename _Tp, typename _Td>
+static inline _Tp __c11_atomic_fetch_sub(_Atomic(_Tp)* __a, _Td __delta,
+                                         memory_order __order) {
+  return __atomic_fetch_sub(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
+                            __gcc_atomic::__to_gcc_order(__order));
+}
+
+template <typename _Tp>
+static inline _Tp __c11_atomic_fetch_and(volatile _Atomic(_Tp)* __a,
+                                         _Tp __pattern, memory_order __order) {
+  return __atomic_fetch_and(&__a->__a_value, __pattern,
+                            __gcc_atomic::__to_gcc_order(__order));
+}
+
+template <typename _Tp>
+static inline _Tp __c11_atomic_fetch_and(_Atomic(_Tp)* __a,
+                                         _Tp __pattern, memory_order __order) {
+  return __atomic_fetch_and(&__a->__a_value, __pattern,
+                            __gcc_atomic::__to_gcc_order(__order));
+}
+
+template <typename _Tp>
+static inline _Tp __c11_atomic_fetch_or(volatile _Atomic(_Tp)* __a,
+                                        _Tp __pattern, memory_order __order) {
+  return __atomic_fetch_or(&__a->__a_value, __pattern,
+                           __gcc_atomic::__to_gcc_order(__order));
+}
+
+template <typename _Tp>
+static inline _Tp __c11_atomic_fetch_or(_Atomic(_Tp)* __a, _Tp __pattern,
+                                        memory_order __order) {
+  return __atomic_fetch_or(&__a->__a_value, __pattern,
+                           __gcc_atomic::__to_gcc_order(__order));
+}
+
+template <typename _Tp>
+static inline _Tp __c11_atomic_fetch_xor(volatile _Atomic(_Tp)* __a,
+                                         _Tp __pattern, memory_order __order) {
+  return __atomic_fetch_xor(&__a->__a_value, __pattern,
+                            __gcc_atomic::__to_gcc_order(__order));
+}
+
+template <typename _Tp>
+static inline _Tp __c11_atomic_fetch_xor(_Atomic(_Tp)* __a, _Tp __pattern,
+                                         memory_order __order) {
+  return __atomic_fetch_xor(&__a->__a_value, __pattern,
+                            __gcc_atomic::__to_gcc_order(__order));
+}
+#endif // _GNUC_VER >= 407
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp
+kill_dependency(_Tp __y) _NOEXCEPT
+{
+    return __y;
+}
+
+// general atomic<T>
+
+template <class _Tp, bool = is_integral<_Tp>::value && !is_same<_Tp, bool>::value>
+struct __atomic_base  // false
+{
+    mutable _Atomic(_Tp) __a_;
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool is_lock_free() const volatile _NOEXCEPT
+    {
+#if __has_feature(cxx_atomic)
+    return __c11_atomic_is_lock_free(sizeof(_Tp));
+#else
+    return __atomic_is_lock_free(sizeof(_Tp), 0);
+#endif
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    bool is_lock_free() const _NOEXCEPT
+        {return static_cast<__atomic_base const volatile*>(this)->is_lock_free();}
+    _LIBCPP_INLINE_VISIBILITY
+    void store(_Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
+        {__c11_atomic_store(&__a_, __d, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    void store(_Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT
+        {__c11_atomic_store(&__a_, __d, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp load(memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT
+        {return __c11_atomic_load(&__a_, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp load(memory_order __m = memory_order_seq_cst) const _NOEXCEPT
+        {return __c11_atomic_load(&__a_, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    operator _Tp() const volatile _NOEXCEPT {return load();}
+    _LIBCPP_INLINE_VISIBILITY
+    operator _Tp() const _NOEXCEPT          {return load();}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp exchange(_Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
+        {return __c11_atomic_exchange(&__a_, __d, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp exchange(_Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT
+        {return __c11_atomic_exchange(&__a_, __d, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool compare_exchange_weak(_Tp& __e, _Tp __d,
+                               memory_order __s, memory_order __f) volatile _NOEXCEPT
+        {return __c11_atomic_compare_exchange_weak(&__a_, &__e, __d, __s, __f);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool compare_exchange_weak(_Tp& __e, _Tp __d,
+                               memory_order __s, memory_order __f) _NOEXCEPT
+        {return __c11_atomic_compare_exchange_weak(&__a_, &__e, __d, __s, __f);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool compare_exchange_strong(_Tp& __e, _Tp __d,
+                                 memory_order __s, memory_order __f) volatile _NOEXCEPT
+        {return __c11_atomic_compare_exchange_strong(&__a_, &__e, __d, __s, __f);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool compare_exchange_strong(_Tp& __e, _Tp __d,
+                                 memory_order __s, memory_order __f) _NOEXCEPT
+        {return __c11_atomic_compare_exchange_strong(&__a_, &__e, __d, __s, __f);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool compare_exchange_weak(_Tp& __e, _Tp __d,
+                              memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
+        {return __c11_atomic_compare_exchange_weak(&__a_, &__e, __d, __m, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool compare_exchange_weak(_Tp& __e, _Tp __d,
+                               memory_order __m = memory_order_seq_cst) _NOEXCEPT
+        {return __c11_atomic_compare_exchange_weak(&__a_, &__e, __d, __m, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool compare_exchange_strong(_Tp& __e, _Tp __d,
+                              memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
+        {return __c11_atomic_compare_exchange_strong(&__a_, &__e, __d, __m, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool compare_exchange_strong(_Tp& __e, _Tp __d,
+                                 memory_order __m = memory_order_seq_cst) _NOEXCEPT
+        {return __c11_atomic_compare_exchange_strong(&__a_, &__e, __d, __m, __m);}
+
+    _LIBCPP_INLINE_VISIBILITY
+#ifndef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+    __atomic_base() _NOEXCEPT = default;
+#else
+    __atomic_base() _NOEXCEPT : __a_() {}
+#endif // _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+
+    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR __atomic_base(_Tp __d) _NOEXCEPT : __a_(__d) {}
+#ifndef _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+    __atomic_base(const __atomic_base&) = delete;
+    __atomic_base& operator=(const __atomic_base&) = delete;
+    __atomic_base& operator=(const __atomic_base&) volatile = delete;
+#else  // _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+private:
+    __atomic_base(const __atomic_base&);
+    __atomic_base& operator=(const __atomic_base&);
+    __atomic_base& operator=(const __atomic_base&) volatile;
+#endif  // _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+};
+
+// atomic<Integral>
+
+template <class _Tp>
+struct __atomic_base<_Tp, true>
+    : public __atomic_base<_Tp, false>
+{
+    typedef __atomic_base<_Tp, false> __base;
+    _LIBCPP_INLINE_VISIBILITY
+    __atomic_base() _NOEXCEPT _LIBCPP_DEFAULT
+    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR __atomic_base(_Tp __d) _NOEXCEPT : __base(__d) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp fetch_add(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
+        {return __c11_atomic_fetch_add(&this->__a_, __op, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp fetch_add(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
+        {return __c11_atomic_fetch_add(&this->__a_, __op, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp fetch_sub(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
+        {return __c11_atomic_fetch_sub(&this->__a_, __op, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp fetch_sub(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
+        {return __c11_atomic_fetch_sub(&this->__a_, __op, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp fetch_and(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
+        {return __c11_atomic_fetch_and(&this->__a_, __op, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp fetch_and(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
+        {return __c11_atomic_fetch_and(&this->__a_, __op, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp fetch_or(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
+        {return __c11_atomic_fetch_or(&this->__a_, __op, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp fetch_or(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
+        {return __c11_atomic_fetch_or(&this->__a_, __op, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp fetch_xor(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
+        {return __c11_atomic_fetch_xor(&this->__a_, __op, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp fetch_xor(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
+        {return __c11_atomic_fetch_xor(&this->__a_, __op, __m);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator++(int) volatile _NOEXCEPT      {return fetch_add(_Tp(1));}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator++(int) _NOEXCEPT               {return fetch_add(_Tp(1));}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator--(int) volatile _NOEXCEPT      {return fetch_sub(_Tp(1));}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator--(int) _NOEXCEPT               {return fetch_sub(_Tp(1));}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator++() volatile _NOEXCEPT         {return fetch_add(_Tp(1)) + _Tp(1);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator++() _NOEXCEPT                  {return fetch_add(_Tp(1)) + _Tp(1);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator--() volatile _NOEXCEPT         {return fetch_sub(_Tp(1)) - _Tp(1);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator--() _NOEXCEPT                  {return fetch_sub(_Tp(1)) - _Tp(1);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator+=(_Tp __op) volatile _NOEXCEPT {return fetch_add(__op) + __op;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator+=(_Tp __op) _NOEXCEPT          {return fetch_add(__op) + __op;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator-=(_Tp __op) volatile _NOEXCEPT {return fetch_sub(__op) - __op;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator-=(_Tp __op) _NOEXCEPT          {return fetch_sub(__op) - __op;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator&=(_Tp __op) volatile _NOEXCEPT {return fetch_and(__op) & __op;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator&=(_Tp __op) _NOEXCEPT          {return fetch_and(__op) & __op;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator|=(_Tp __op) volatile _NOEXCEPT {return fetch_or(__op) | __op;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator|=(_Tp __op) _NOEXCEPT          {return fetch_or(__op) | __op;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator^=(_Tp __op) volatile _NOEXCEPT {return fetch_xor(__op) ^ __op;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator^=(_Tp __op) _NOEXCEPT          {return fetch_xor(__op) ^ __op;}
+};
+
+// atomic<T>
+
+template <class _Tp>
+struct atomic
+    : public __atomic_base<_Tp>
+{
+    typedef __atomic_base<_Tp> __base;
+    _LIBCPP_INLINE_VISIBILITY
+    atomic() _NOEXCEPT _LIBCPP_DEFAULT
+    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR atomic(_Tp __d) _NOEXCEPT : __base(__d) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator=(_Tp __d) volatile _NOEXCEPT
+        {__base::store(__d); return __d;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp operator=(_Tp __d) _NOEXCEPT
+        {__base::store(__d); return __d;}
+};
+
+// atomic<T*>
+
+template <class _Tp>
+struct atomic<_Tp*>
+    : public __atomic_base<_Tp*>
+{
+    typedef __atomic_base<_Tp*> __base;
+    _LIBCPP_INLINE_VISIBILITY
+    atomic() _NOEXCEPT _LIBCPP_DEFAULT
+    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR atomic(_Tp* __d) _NOEXCEPT : __base(__d) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* operator=(_Tp* __d) volatile _NOEXCEPT
+        {__base::store(__d); return __d;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* operator=(_Tp* __d) _NOEXCEPT
+        {__base::store(__d); return __d;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* fetch_add(ptrdiff_t __op, memory_order __m = memory_order_seq_cst)
+                                                                        volatile _NOEXCEPT
+        {return __c11_atomic_fetch_add(&this->__a_, __op, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* fetch_add(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
+        {return __c11_atomic_fetch_add(&this->__a_, __op, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* fetch_sub(ptrdiff_t __op, memory_order __m = memory_order_seq_cst)
+                                                                        volatile _NOEXCEPT
+        {return __c11_atomic_fetch_sub(&this->__a_, __op, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* fetch_sub(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
+        {return __c11_atomic_fetch_sub(&this->__a_, __op, __m);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* operator++(int) volatile _NOEXCEPT            {return fetch_add(1);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* operator++(int) _NOEXCEPT                     {return fetch_add(1);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* operator--(int) volatile _NOEXCEPT            {return fetch_sub(1);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* operator--(int) _NOEXCEPT                     {return fetch_sub(1);}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* operator++() volatile _NOEXCEPT               {return fetch_add(1) + 1;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* operator++() _NOEXCEPT                        {return fetch_add(1) + 1;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* operator--() volatile _NOEXCEPT               {return fetch_sub(1) - 1;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* operator--() _NOEXCEPT                        {return fetch_sub(1) - 1;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* operator+=(ptrdiff_t __op) volatile _NOEXCEPT {return fetch_add(__op) + __op;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* operator+=(ptrdiff_t __op) _NOEXCEPT          {return fetch_add(__op) + __op;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* operator-=(ptrdiff_t __op) volatile _NOEXCEPT {return fetch_sub(__op) - __op;}
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* operator-=(ptrdiff_t __op) _NOEXCEPT          {return fetch_sub(__op) - __op;}
+};
+
+// atomic_is_lock_free
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_is_lock_free(const volatile atomic<_Tp>* __o) _NOEXCEPT
+{
+    return __o->is_lock_free();
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_is_lock_free(const atomic<_Tp>* __o) _NOEXCEPT
+{
+    return __o->is_lock_free();
+}
+
+// atomic_init
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+atomic_init(volatile atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
+{
+    __c11_atomic_init(&__o->__a_, __d);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+atomic_init(atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
+{
+    __c11_atomic_init(&__o->__a_, __d);
+}
+
+// atomic_store
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+atomic_store(volatile atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
+{
+    __o->store(__d);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+atomic_store(atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
+{
+    __o->store(__d);
+}
+
+// atomic_store_explicit
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+atomic_store_explicit(volatile atomic<_Tp>* __o, _Tp __d, memory_order __m) _NOEXCEPT
+{
+    __o->store(__d, __m);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+atomic_store_explicit(atomic<_Tp>* __o, _Tp __d, memory_order __m) _NOEXCEPT
+{
+    __o->store(__d, __m);
+}
+
+// atomic_load
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp
+atomic_load(const volatile atomic<_Tp>* __o) _NOEXCEPT
+{
+    return __o->load();
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp
+atomic_load(const atomic<_Tp>* __o) _NOEXCEPT
+{
+    return __o->load();
+}
+
+// atomic_load_explicit
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp
+atomic_load_explicit(const volatile atomic<_Tp>* __o, memory_order __m) _NOEXCEPT
+{
+    return __o->load(__m);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp
+atomic_load_explicit(const atomic<_Tp>* __o, memory_order __m) _NOEXCEPT
+{
+    return __o->load(__m);
+}
+
+// atomic_exchange
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp
+atomic_exchange(volatile atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
+{
+    return __o->exchange(__d);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp
+atomic_exchange(atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
+{
+    return __o->exchange(__d);
+}
+
+// atomic_exchange_explicit
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp
+atomic_exchange_explicit(volatile atomic<_Tp>* __o, _Tp __d, memory_order __m) _NOEXCEPT
+{
+    return __o->exchange(__d, __m);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp
+atomic_exchange_explicit(atomic<_Tp>* __o, _Tp __d, memory_order __m) _NOEXCEPT
+{
+    return __o->exchange(__d, __m);
+}
+
+// atomic_compare_exchange_weak
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_compare_exchange_weak(volatile atomic<_Tp>* __o, _Tp* __e, _Tp __d) _NOEXCEPT
+{
+    return __o->compare_exchange_weak(*__e, __d);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_compare_exchange_weak(atomic<_Tp>* __o, _Tp* __e, _Tp __d) _NOEXCEPT
+{
+    return __o->compare_exchange_weak(*__e, __d);
+}
+
+// atomic_compare_exchange_strong
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_compare_exchange_strong(volatile atomic<_Tp>* __o, _Tp* __e, _Tp __d) _NOEXCEPT
+{
+    return __o->compare_exchange_strong(*__e, __d);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_compare_exchange_strong(atomic<_Tp>* __o, _Tp* __e, _Tp __d) _NOEXCEPT
+{
+    return __o->compare_exchange_strong(*__e, __d);
+}
+
+// atomic_compare_exchange_weak_explicit
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_compare_exchange_weak_explicit(volatile atomic<_Tp>* __o, _Tp* __e,
+                                      _Tp __d,
+                                      memory_order __s, memory_order __f) _NOEXCEPT
+{
+    return __o->compare_exchange_weak(*__e, __d, __s, __f);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_compare_exchange_weak_explicit(atomic<_Tp>* __o, _Tp* __e, _Tp __d,
+                                      memory_order __s, memory_order __f) _NOEXCEPT
+{
+    return __o->compare_exchange_weak(*__e, __d, __s, __f);
+}
+
+// atomic_compare_exchange_strong_explicit
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_compare_exchange_strong_explicit(volatile atomic<_Tp>* __o,
+                                        _Tp* __e, _Tp __d,
+                                        memory_order __s, memory_order __f) _NOEXCEPT
+{
+    return __o->compare_exchange_strong(*__e, __d, __s, __f);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_compare_exchange_strong_explicit(atomic<_Tp>* __o, _Tp* __e,
+                                        _Tp __d,
+                                        memory_order __s, memory_order __f) _NOEXCEPT
+{
+    return __o->compare_exchange_strong(*__e, __d, __s, __f);
+}
+
+// atomic_fetch_add
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_add(volatile atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
+{
+    return __o->fetch_add(__op);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_add(atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
+{
+    return __o->fetch_add(__op);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp*
+atomic_fetch_add(volatile atomic<_Tp*>* __o, ptrdiff_t __op) _NOEXCEPT
+{
+    return __o->fetch_add(__op);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp*
+atomic_fetch_add(atomic<_Tp*>* __o, ptrdiff_t __op) _NOEXCEPT
+{
+    return __o->fetch_add(__op);
+}
+
+// atomic_fetch_add_explicit
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_add_explicit(volatile atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
+{
+    return __o->fetch_add(__op, __m);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_add_explicit(atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
+{
+    return __o->fetch_add(__op, __m);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp*
+atomic_fetch_add_explicit(volatile atomic<_Tp*>* __o, ptrdiff_t __op,
+                          memory_order __m) _NOEXCEPT
+{
+    return __o->fetch_add(__op, __m);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp*
+atomic_fetch_add_explicit(atomic<_Tp*>* __o, ptrdiff_t __op, memory_order __m) _NOEXCEPT
+{
+    return __o->fetch_add(__op, __m);
+}
+
+// atomic_fetch_sub
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_sub(volatile atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
+{
+    return __o->fetch_sub(__op);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_sub(atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
+{
+    return __o->fetch_sub(__op);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp*
+atomic_fetch_sub(volatile atomic<_Tp*>* __o, ptrdiff_t __op) _NOEXCEPT
+{
+    return __o->fetch_sub(__op);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp*
+atomic_fetch_sub(atomic<_Tp*>* __o, ptrdiff_t __op) _NOEXCEPT
+{
+    return __o->fetch_sub(__op);
+}
+
+// atomic_fetch_sub_explicit
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_sub_explicit(volatile atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
+{
+    return __o->fetch_sub(__op, __m);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_sub_explicit(atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
+{
+    return __o->fetch_sub(__op, __m);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp*
+atomic_fetch_sub_explicit(volatile atomic<_Tp*>* __o, ptrdiff_t __op,
+                          memory_order __m) _NOEXCEPT
+{
+    return __o->fetch_sub(__op, __m);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp*
+atomic_fetch_sub_explicit(atomic<_Tp*>* __o, ptrdiff_t __op, memory_order __m) _NOEXCEPT
+{
+    return __o->fetch_sub(__op, __m);
+}
+
+// atomic_fetch_and
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_and(volatile atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
+{
+    return __o->fetch_and(__op);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_and(atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
+{
+    return __o->fetch_and(__op);
+}
+
+// atomic_fetch_and_explicit
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_and_explicit(volatile atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
+{
+    return __o->fetch_and(__op, __m);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_and_explicit(atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
+{
+    return __o->fetch_and(__op, __m);
+}
+
+// atomic_fetch_or
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_or(volatile atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
+{
+    return __o->fetch_or(__op);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_or(atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
+{
+    return __o->fetch_or(__op);
+}
+
+// atomic_fetch_or_explicit
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_or_explicit(volatile atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
+{
+    return __o->fetch_or(__op, __m);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_or_explicit(atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
+{
+    return __o->fetch_or(__op, __m);
+}
+
+// atomic_fetch_xor
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_xor(volatile atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
+{
+    return __o->fetch_xor(__op);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_xor(atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
+{
+    return __o->fetch_xor(__op);
+}
+
+// atomic_fetch_xor_explicit
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_xor_explicit(volatile atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
+{
+    return __o->fetch_xor(__op, __m);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
+    _Tp
+>::type
+atomic_fetch_xor_explicit(atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
+{
+    return __o->fetch_xor(__op, __m);
+}
+
+// flag type and operations
+
+typedef struct atomic_flag
+{
+    _Atomic(bool) __a_;
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool test_and_set(memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
+        {return __c11_atomic_exchange(&__a_, true, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool test_and_set(memory_order __m = memory_order_seq_cst) _NOEXCEPT
+        {return __c11_atomic_exchange(&__a_, true, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    void clear(memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
+        {__c11_atomic_store(&__a_, false, __m);}
+    _LIBCPP_INLINE_VISIBILITY
+    void clear(memory_order __m = memory_order_seq_cst) _NOEXCEPT
+        {__c11_atomic_store(&__a_, false, __m);}
+
+    _LIBCPP_INLINE_VISIBILITY
+#ifndef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+    atomic_flag() _NOEXCEPT = default;
+#else
+    atomic_flag() _NOEXCEPT : __a_() {}
+#endif // _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+
+    _LIBCPP_INLINE_VISIBILITY
+    atomic_flag(bool __b) _NOEXCEPT : __a_(__b) {}
+
+#ifndef _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+    atomic_flag(const atomic_flag&) = delete;
+    atomic_flag& operator=(const atomic_flag&) = delete;
+    atomic_flag& operator=(const atomic_flag&) volatile = delete;
+#else  // _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+private:
+    atomic_flag(const atomic_flag&);
+    atomic_flag& operator=(const atomic_flag&);
+    atomic_flag& operator=(const atomic_flag&) volatile;
+#endif  // _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+} atomic_flag;
+
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_flag_test_and_set(volatile atomic_flag* __o) _NOEXCEPT
+{
+    return __o->test_and_set();
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_flag_test_and_set(atomic_flag* __o) _NOEXCEPT
+{
+    return __o->test_and_set();
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_flag_test_and_set_explicit(volatile atomic_flag* __o, memory_order __m) _NOEXCEPT
+{
+    return __o->test_and_set(__m);
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_flag_test_and_set_explicit(atomic_flag* __o, memory_order __m) _NOEXCEPT
+{
+    return __o->test_and_set(__m);
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+void
+atomic_flag_clear(volatile atomic_flag* __o) _NOEXCEPT
+{
+    __o->clear();
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+void
+atomic_flag_clear(atomic_flag* __o) _NOEXCEPT
+{
+    __o->clear();
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+void
+atomic_flag_clear_explicit(volatile atomic_flag* __o, memory_order __m) _NOEXCEPT
+{
+    __o->clear(__m);
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+void
+atomic_flag_clear_explicit(atomic_flag* __o, memory_order __m) _NOEXCEPT
+{
+    __o->clear(__m);
+}
+
+// fences
+
+inline _LIBCPP_INLINE_VISIBILITY
+void
+atomic_thread_fence(memory_order __m) _NOEXCEPT
+{
+    __c11_atomic_thread_fence(__m);
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+void
+atomic_signal_fence(memory_order __m) _NOEXCEPT
+{
+    __c11_atomic_signal_fence(__m);
+}
+
+// Atomics for standard typedef types
+
+typedef atomic<bool>               atomic_bool;
+typedef atomic<char>               atomic_char;
+typedef atomic<signed char>        atomic_schar;
+typedef atomic<unsigned char>      atomic_uchar;
+typedef atomic<short>              atomic_short;
+typedef atomic<unsigned short>     atomic_ushort;
+typedef atomic<int>                atomic_int;
+typedef atomic<unsigned int>       atomic_uint;
+typedef atomic<long>               atomic_long;
+typedef atomic<unsigned long>      atomic_ulong;
+typedef atomic<long long>          atomic_llong;
+typedef atomic<unsigned long long> atomic_ullong;
+typedef atomic<char16_t>           atomic_char16_t;
+typedef atomic<char32_t>           atomic_char32_t;
+typedef atomic<wchar_t>            atomic_wchar_t;
+
+typedef atomic<int_least8_t>   atomic_int_least8_t;
+typedef atomic<uint_least8_t>  atomic_uint_least8_t;
+typedef atomic<int_least16_t>  atomic_int_least16_t;
+typedef atomic<uint_least16_t> atomic_uint_least16_t;
+typedef atomic<int_least32_t>  atomic_int_least32_t;
+typedef atomic<uint_least32_t> atomic_uint_least32_t;
+typedef atomic<int_least64_t>  atomic_int_least64_t;
+typedef atomic<uint_least64_t> atomic_uint_least64_t;
+
+typedef atomic<int_fast8_t>   atomic_int_fast8_t;
+typedef atomic<uint_fast8_t>  atomic_uint_fast8_t;
+typedef atomic<int_fast16_t>  atomic_int_fast16_t;
+typedef atomic<uint_fast16_t> atomic_uint_fast16_t;
+typedef atomic<int_fast32_t>  atomic_int_fast32_t;
+typedef atomic<uint_fast32_t> atomic_uint_fast32_t;
+typedef atomic<int_fast64_t>  atomic_int_fast64_t;
+typedef atomic<uint_fast64_t> atomic_uint_fast64_t;
+
+typedef atomic<intptr_t>  atomic_intptr_t;
+typedef atomic<uintptr_t> atomic_uintptr_t;
+typedef atomic<size_t>    atomic_size_t;
+typedef atomic<ptrdiff_t> atomic_ptrdiff_t;
+typedef atomic<intmax_t>  atomic_intmax_t;
+typedef atomic<uintmax_t> atomic_uintmax_t;
+
+#define ATOMIC_FLAG_INIT {false}
+#define ATOMIC_VAR_INIT(__v) {__v}
+
+// lock-free property
+
+#define ATOMIC_BOOL_LOCK_FREE      __GCC_ATOMIC_BOOL_LOCK_FREE
+#define ATOMIC_CHAR_LOCK_FREE      __GCC_ATOMIC_CHAR_LOCK_FREE
+#define ATOMIC_CHAR16_T_LOCK_FREE  __GCC_ATOMIC_CHAR16_T_LOCK_FREE
+#define ATOMIC_CHAR32_T_LOCK_FREE  __GCC_ATOMIC_CHAR32_T_LOCK_FREE
+#define ATOMIC_WCHAR_T_LOCK_FREE   __GCC_ATOMIC_WCHAR_T_LOCK_FREE
+#define ATOMIC_SHORT_LOCK_FREE     __GCC_ATOMIC_SHORT_LOCK_FREE
+#define ATOMIC_INT_LOCK_FREE       __GCC_ATOMIC_INT_LOCK_FREE
+#define ATOMIC_LONG_LOCK_FREE      __GCC_ATOMIC_LONG_LOCK_FREE
+#define ATOMIC_LLONG_LOCK_FREE     __GCC_ATOMIC_LLONG_LOCK_FREE
+#define ATOMIC_POINTER_LOCK_FREE   __GCC_ATOMIC_POINTER_LOCK_FREE
+
+#endif  //  !__has_feature(cxx_atomic)
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // !_LIBCPP_HAS_NO_THREADS
+
+#endif  // _LIBCPP_ATOMIC

diff --git a/libcxx/include/bitset b/libcxx/include/bitset
new file mode 100644
index 0000000..8c278cc
--- /dev/null
+++ b/libcxx/include/bitset

@@ -0,0 +1,1081 @@
+// -*- C++ -*-
+//===---------------------------- bitset ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_BITSET
+#define _LIBCPP_BITSET
+
+/*
+    bitset synopsis
+
+namespace std
+{
+
+namespace std {
+
+template <size_t N>
+class bitset
+{
+public:
+    // bit reference:
+    class reference
+    {
+        friend class bitset;
+        reference() noexcept;
+    public:
+        ~reference() noexcept;
+        reference& operator=(bool x) noexcept;           // for b[i] = x;
+        reference& operator=(const reference&) noexcept; // for b[i] = b[j];
+        bool operator~() const noexcept;                 // flips the bit
+        operator bool() const noexcept;                  // for x = b[i];
+        reference& flip() noexcept;                      // for b[i].flip();
+    };
+
+    // 23.3.5.1 constructors:
+    constexpr bitset() noexcept;
+    constexpr bitset(unsigned long long val) noexcept;
+    template <class charT>
+        explicit bitset(const charT* str,
+                        typename basic_string<charT>::size_type n = basic_string<charT>::npos,
+                        charT zero = charT('0'), charT one = charT('1'));
+    template<class charT, class traits, class Allocator>
+        explicit bitset(const basic_string<charT,traits,Allocator>& str,
+                        typename basic_string<charT,traits,Allocator>::size_type pos = 0,
+                        typename basic_string<charT,traits,Allocator>::size_type n =
+                                 basic_string<charT,traits,Allocator>::npos,
+                        charT zero = charT('0'), charT one = charT('1'));
+
+    // 23.3.5.2 bitset operations:
+    bitset& operator&=(const bitset& rhs) noexcept;
+    bitset& operator|=(const bitset& rhs) noexcept;
+    bitset& operator^=(const bitset& rhs) noexcept;
+    bitset& operator<<=(size_t pos) noexcept;
+    bitset& operator>>=(size_t pos) noexcept;
+    bitset& set() noexcept;
+    bitset& set(size_t pos, bool val = true);
+    bitset& reset() noexcept;
+    bitset& reset(size_t pos);
+    bitset operator~() const noexcept;
+    bitset& flip() noexcept;
+    bitset& flip(size_t pos);
+
+    // element access:
+    constexpr bool operator[](size_t pos) const; // for b[i];
+    reference operator[](size_t pos);            // for b[i];
+    unsigned long to_ulong() const;
+    unsigned long long to_ullong() const;
+    template <class charT, class traits, class Allocator>
+        basic_string<charT, traits, Allocator> to_string(charT zero = charT('0'), charT one = charT('1')) const;
+    template <class charT, class traits>
+        basic_string<charT, traits, allocator<charT> > to_string(charT zero = charT('0'), charT one = charT('1')) const;
+    template <class charT>
+        basic_string<charT, char_traits<charT>, allocator<charT> > to_string(charT zero = charT('0'), charT one = charT('1')) const;
+    basic_string<char, char_traits<char>, allocator<char> > to_string(char zero = '0', char one = '1') const;
+    size_t count() const noexcept;
+    constexpr size_t size() const noexcept;
+    bool operator==(const bitset& rhs) const noexcept;
+    bool operator!=(const bitset& rhs) const noexcept;
+    bool test(size_t pos) const;
+    bool all() const noexcept;
+    bool any() const noexcept;
+    bool none() const noexcept;
+    bitset operator<<(size_t pos) const noexcept;
+    bitset operator>>(size_t pos) const noexcept;
+};
+
+// 23.3.5.3 bitset operators:
+template <size_t N>
+bitset<N> operator&(const bitset<N>&, const bitset<N>&) noexcept;
+
+template <size_t N>
+bitset<N> operator|(const bitset<N>&, const bitset<N>&) noexcept;
+
+template <size_t N>
+bitset<N> operator^(const bitset<N>&, const bitset<N>&) noexcept;
+
+template <class charT, class traits, size_t N>
+basic_istream<charT, traits>&
+operator>>(basic_istream<charT, traits>& is, bitset<N>& x);
+
+template <class charT, class traits, size_t N>
+basic_ostream<charT, traits>&
+operator<<(basic_ostream<charT, traits>& os, const bitset<N>& x);
+
+template <size_t N> struct hash<std::bitset<N>>;
+
+}  // std
+
+*/
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#include <__config>
+#include <__bit_reference>
+#include <cstddef>
+#include <climits>
+#include <string>
+#include <stdexcept>
+#include <iosfwd>
+#include <__functional_base>
+#if defined(_LIBCPP_NO_EXCEPTIONS)
+    #include <cassert>
+#endif
+
+#include <__undef_min_max>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <size_t _N_words, size_t _Size>
+class __bitset;
+
+template <size_t _N_words, size_t _Size>
+struct __has_storage_type<__bitset<_N_words, _Size> >
+{
+    static const bool value = true;
+};
+
+template <size_t _N_words, size_t _Size>
+class __bitset
+{
+public:
+    typedef ptrdiff_t              difference_type;
+    typedef size_t                 size_type;
+    typedef size_type              __storage_type;
+protected:
+    typedef __bitset __self;
+    typedef       __storage_type*  __storage_pointer;
+    typedef const __storage_type*  __const_storage_pointer;
+    static const unsigned __bits_per_word = static_cast<unsigned>(sizeof(__storage_type) * CHAR_BIT);
+
+    friend class __bit_reference<__bitset>;
+    friend class __bit_const_reference<__bitset>;
+    friend class __bit_iterator<__bitset, false>;
+    friend class __bit_iterator<__bitset, true>;
+    friend struct __bit_array<__bitset>;
+
+    __storage_type __first_[_N_words];
+
+    typedef __bit_reference<__bitset>                  reference;
+    typedef __bit_const_reference<__bitset>            const_reference;
+    typedef __bit_iterator<__bitset, false>            iterator;
+    typedef __bit_iterator<__bitset, true>             const_iterator;
+
+    _LIBCPP_CONSTEXPR __bitset() _NOEXCEPT;
+    explicit _LIBCPP_CONSTEXPR __bitset(unsigned long long __v) _NOEXCEPT;
+
+    _LIBCPP_INLINE_VISIBILITY reference __make_ref(size_t __pos) _NOEXCEPT
+        {return reference(__first_ + __pos / __bits_per_word, __storage_type(1) << __pos % __bits_per_word);}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR const_reference __make_ref(size_t __pos) const _NOEXCEPT
+        {return const_reference(__first_ + __pos / __bits_per_word, __storage_type(1) << __pos % __bits_per_word);}
+    _LIBCPP_INLINE_VISIBILITY iterator __make_iter(size_t __pos) _NOEXCEPT
+        {return iterator(__first_ + __pos / __bits_per_word, __pos % __bits_per_word);}
+    _LIBCPP_INLINE_VISIBILITY const_iterator __make_iter(size_t __pos) const _NOEXCEPT
+        {return const_iterator(__first_ + __pos / __bits_per_word, __pos % __bits_per_word);}
+
+    void operator&=(const __bitset& __v) _NOEXCEPT;
+    void operator|=(const __bitset& __v) _NOEXCEPT;
+    void operator^=(const __bitset& __v) _NOEXCEPT;
+
+    void flip() _NOEXCEPT;
+    _LIBCPP_INLINE_VISIBILITY unsigned long to_ulong() const
+        {return to_ulong(integral_constant<bool, _Size < sizeof(unsigned long) * CHAR_BIT>());}
+    _LIBCPP_INLINE_VISIBILITY unsigned long long to_ullong() const
+        {return to_ullong(integral_constant<bool, _Size < sizeof(unsigned long long) * CHAR_BIT>());}
+
+    bool all() const _NOEXCEPT;
+    bool any() const _NOEXCEPT;
+    size_t __hash_code() const _NOEXCEPT;
+private:
+#ifdef _LIBCPP_HAS_NO_CONSTEXPR
+    void __init(unsigned long long __v, false_type) _NOEXCEPT;
+    void __init(unsigned long long __v, true_type) _NOEXCEPT;
+#endif  // _LIBCPP_HAS_NO_CONSTEXPR
+    unsigned long to_ulong(false_type) const;
+    unsigned long to_ulong(true_type) const;
+    unsigned long long to_ullong(false_type) const;
+    unsigned long long to_ullong(true_type) const;
+    unsigned long long to_ullong(true_type, false_type) const;
+    unsigned long long to_ullong(true_type, true_type) const;
+};
+
+template <size_t _N_words, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+__bitset<_N_words, _Size>::__bitset() _NOEXCEPT
+#ifndef _LIBCPP_HAS_NO_CONSTEXPR
+    : __first_{0}
+#endif
+{
+#ifdef _LIBCPP_HAS_NO_CONSTEXPR
+    _VSTD::fill_n(__first_, _N_words, __storage_type(0));
+#endif
+}
+
+#ifdef _LIBCPP_HAS_NO_CONSTEXPR
+
+template <size_t _N_words, size_t _Size>
+void
+__bitset<_N_words, _Size>::__init(unsigned long long __v, false_type) _NOEXCEPT
+{
+    __storage_type __t[sizeof(unsigned long long) / sizeof(__storage_type)];
+    for (size_t __i = 0; __i < sizeof(__t)/sizeof(__t[0]); ++__i, __v >>= __bits_per_word)
+        __t[__i] = static_cast<__storage_type>(__v);
+    _VSTD::copy(__t, __t + sizeof(__t)/sizeof(__t[0]), __first_);
+    _VSTD::fill(__first_ + sizeof(__t)/sizeof(__t[0]), __first_ + sizeof(__first_)/sizeof(__first_[0]),
+               __storage_type(0));
+}
+
+template <size_t _N_words, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__bitset<_N_words, _Size>::__init(unsigned long long __v, true_type) _NOEXCEPT
+{
+    __first_[0] = __v;
+    _VSTD::fill(__first_ + 1, __first_ + sizeof(__first_)/sizeof(__first_[0]), __storage_type(0));
+}
+
+#endif  // _LIBCPP_HAS_NO_CONSTEXPR
+
+template <size_t _N_words, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+__bitset<_N_words, _Size>::__bitset(unsigned long long __v) _NOEXCEPT
+#ifndef _LIBCPP_HAS_NO_CONSTEXPR
+#if __SIZEOF_SIZE_T__ == 8
+    : __first_{__v}
+#elif __SIZEOF_SIZE_T__ == 4
+    : __first_{__v, __v >> __bits_per_word}
+#else
+#error This constructor has not been ported to this platform
+#endif
+#endif
+{
+#ifdef _LIBCPP_HAS_NO_CONSTEXPR
+    __init(__v, integral_constant<bool, sizeof(unsigned long long) == sizeof(__storage_type)>());
+#endif
+}
+
+template <size_t _N_words, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__bitset<_N_words, _Size>::operator&=(const __bitset& __v) _NOEXCEPT
+{
+    for (size_type __i = 0; __i < _N_words; ++__i)
+        __first_[__i] &= __v.__first_[__i];
+}
+
+template <size_t _N_words, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__bitset<_N_words, _Size>::operator|=(const __bitset& __v) _NOEXCEPT
+{
+    for (size_type __i = 0; __i < _N_words; ++__i)
+        __first_[__i] |= __v.__first_[__i];
+}
+
+template <size_t _N_words, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__bitset<_N_words, _Size>::operator^=(const __bitset& __v) _NOEXCEPT
+{
+    for (size_type __i = 0; __i < _N_words; ++__i)
+        __first_[__i] ^= __v.__first_[__i];
+}
+
+template <size_t _N_words, size_t _Size>
+void
+__bitset<_N_words, _Size>::flip() _NOEXCEPT
+{
+    // do middle whole words
+    size_type __n = _Size;
+    __storage_pointer __p = __first_;
+    for (; __n >= __bits_per_word; ++__p, __n -= __bits_per_word)
+        *__p = ~*__p;
+    // do last partial word
+    if (__n > 0)
+    {
+        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
+        __storage_type __b = *__p & __m;
+        *__p &= ~__m;
+        *__p |= ~__b & __m;
+    }
+}
+
+template <size_t _N_words, size_t _Size>
+unsigned long
+__bitset<_N_words, _Size>::to_ulong(false_type) const
+{
+    const_iterator __e = __make_iter(_Size);
+    const_iterator __i = _VSTD::find(__make_iter(sizeof(unsigned long) * CHAR_BIT), __e, true);
+    if (__i != __e)
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        throw overflow_error("bitset to_ulong overflow error");
+#else
+        assert(!"bitset to_ulong overflow error");
+#endif
+    return __first_[0];
+}
+
+template <size_t _N_words, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+unsigned long
+__bitset<_N_words, _Size>::to_ulong(true_type) const
+{
+    return __first_[0];
+}
+
+template <size_t _N_words, size_t _Size>
+unsigned long long
+__bitset<_N_words, _Size>::to_ullong(false_type) const
+{
+    const_iterator __e = __make_iter(_Size);
+    const_iterator __i = _VSTD::find(__make_iter(sizeof(unsigned long long) * CHAR_BIT), __e, true);
+    if (__i != __e)
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        throw overflow_error("bitset to_ullong overflow error");
+#else
+        assert(!"bitset to_ullong overflow error");
+#endif
+    return to_ullong(true_type());
+}
+
+template <size_t _N_words, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+unsigned long long
+__bitset<_N_words, _Size>::to_ullong(true_type) const
+{
+    return to_ullong(true_type(), integral_constant<bool, sizeof(__storage_type) < sizeof(unsigned long long)>());
+}
+
+template <size_t _N_words, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+unsigned long long
+__bitset<_N_words, _Size>::to_ullong(true_type, false_type) const
+{
+    return __first_[0];
+}
+
+template <size_t _N_words, size_t _Size>
+unsigned long long
+__bitset<_N_words, _Size>::to_ullong(true_type, true_type) const
+{
+    unsigned long long __r = __first_[0];
+    for (std::size_t __i = 1; __i < sizeof(unsigned long long) / sizeof(__storage_type); ++__i)
+        __r |= static_cast<unsigned long long>(__first_[__i]) << (sizeof(__storage_type) * CHAR_BIT);
+    return __r;
+}
+
+template <size_t _N_words, size_t _Size>
+bool
+__bitset<_N_words, _Size>::all() const _NOEXCEPT
+{
+    // do middle whole words
+    size_type __n = _Size;
+    __const_storage_pointer __p = __first_;
+    for (; __n >= __bits_per_word; ++__p, __n -= __bits_per_word)
+        if (~*__p)
+            return false;
+    // do last partial word
+    if (__n > 0)
+    {
+        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
+        if (~*__p & __m)
+            return false;
+    }
+    return true;
+}
+
+template <size_t _N_words, size_t _Size>
+bool
+__bitset<_N_words, _Size>::any() const _NOEXCEPT
+{
+    // do middle whole words
+    size_type __n = _Size;
+    __const_storage_pointer __p = __first_;
+    for (; __n >= __bits_per_word; ++__p, __n -= __bits_per_word)
+        if (*__p)
+            return true;
+    // do last partial word
+    if (__n > 0)
+    {
+        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
+        if (*__p & __m)
+            return true;
+    }
+    return false;
+}
+
+template <size_t _N_words, size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+size_t
+__bitset<_N_words, _Size>::__hash_code() const _NOEXCEPT
+{
+    size_t __h = 0;
+    for (size_type __i = 0; __i < _N_words; ++__i)
+        __h ^= __first_[__i];
+    return __h;
+}
+
+template <size_t _Size>
+class __bitset<1, _Size>
+{
+public:
+    typedef ptrdiff_t              difference_type;
+    typedef size_t                 size_type;
+    typedef size_type              __storage_type;
+protected:
+    typedef __bitset __self;
+    typedef       __storage_type*  __storage_pointer;
+    typedef const __storage_type*  __const_storage_pointer;
+    static const unsigned __bits_per_word = static_cast<unsigned>(sizeof(__storage_type) * CHAR_BIT);
+
+    friend class __bit_reference<__bitset>;
+    friend class __bit_const_reference<__bitset>;
+    friend class __bit_iterator<__bitset, false>;
+    friend class __bit_iterator<__bitset, true>;
+    friend struct __bit_array<__bitset>;
+
+    __storage_type __first_;
+
+    typedef __bit_reference<__bitset>                  reference;
+    typedef __bit_const_reference<__bitset>            const_reference;
+    typedef __bit_iterator<__bitset, false>            iterator;
+    typedef __bit_iterator<__bitset, true>             const_iterator;
+
+    _LIBCPP_CONSTEXPR __bitset() _NOEXCEPT;
+    explicit _LIBCPP_CONSTEXPR __bitset(unsigned long long __v) _NOEXCEPT;
+
+    _LIBCPP_INLINE_VISIBILITY reference __make_ref(size_t __pos) _NOEXCEPT
+        {return reference(&__first_, __storage_type(1) << __pos);}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR const_reference __make_ref(size_t __pos) const _NOEXCEPT
+        {return const_reference(&__first_, __storage_type(1) << __pos);}
+    _LIBCPP_INLINE_VISIBILITY iterator __make_iter(size_t __pos) _NOEXCEPT
+        {return iterator(&__first_ + __pos / __bits_per_word, __pos % __bits_per_word);}
+    _LIBCPP_INLINE_VISIBILITY const_iterator __make_iter(size_t __pos) const _NOEXCEPT
+        {return const_iterator(&__first_ + __pos / __bits_per_word, __pos % __bits_per_word);}
+
+    void operator&=(const __bitset& __v) _NOEXCEPT;
+    void operator|=(const __bitset& __v) _NOEXCEPT;
+    void operator^=(const __bitset& __v) _NOEXCEPT;
+
+    void flip() _NOEXCEPT;
+
+    unsigned long to_ulong() const;
+    unsigned long long to_ullong() const;
+
+    bool all() const _NOEXCEPT;
+    bool any() const _NOEXCEPT;
+
+    size_t __hash_code() const _NOEXCEPT;
+};
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+__bitset<1, _Size>::__bitset() _NOEXCEPT
+    : __first_(0)
+{
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+__bitset<1, _Size>::__bitset(unsigned long long __v) _NOEXCEPT
+    : __first_(static_cast<__storage_type>(__v))
+{
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__bitset<1, _Size>::operator&=(const __bitset& __v) _NOEXCEPT
+{
+    __first_ &= __v.__first_;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__bitset<1, _Size>::operator|=(const __bitset& __v) _NOEXCEPT
+{
+    __first_ |= __v.__first_;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__bitset<1, _Size>::operator^=(const __bitset& __v) _NOEXCEPT
+{
+    __first_ ^= __v.__first_;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__bitset<1, _Size>::flip() _NOEXCEPT
+{
+    __storage_type __m = ~__storage_type(0) >> (__bits_per_word - _Size);
+    __first_ = ~__first_;
+    __first_ &= __m;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+unsigned long
+__bitset<1, _Size>::to_ulong() const
+{
+    return __first_;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+unsigned long long
+__bitset<1, _Size>::to_ullong() const
+{
+    return __first_;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+__bitset<1, _Size>::all() const _NOEXCEPT
+{
+    __storage_type __m = ~__storage_type(0) >> (__bits_per_word - _Size);
+    return !(~__first_ & __m);
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+__bitset<1, _Size>::any() const _NOEXCEPT
+{
+    __storage_type __m = ~__storage_type(0) >> (__bits_per_word - _Size);
+    return __first_ & __m;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+size_t
+__bitset<1, _Size>::__hash_code() const _NOEXCEPT
+{
+    return __first_;
+}
+
+template <>
+class __bitset<0, 0>
+{
+public:
+    typedef ptrdiff_t              difference_type;
+    typedef size_t                 size_type;
+    typedef size_type              __storage_type;
+protected:
+    typedef __bitset __self;
+    typedef       __storage_type*  __storage_pointer;
+    typedef const __storage_type*  __const_storage_pointer;
+    static const unsigned __bits_per_word = static_cast<unsigned>(sizeof(__storage_type) * CHAR_BIT);
+
+    friend class __bit_reference<__bitset>;
+    friend class __bit_const_reference<__bitset>;
+    friend class __bit_iterator<__bitset, false>;
+    friend class __bit_iterator<__bitset, true>;
+    friend struct __bit_array<__bitset>;
+
+    typedef __bit_reference<__bitset>                  reference;
+    typedef __bit_const_reference<__bitset>            const_reference;
+    typedef __bit_iterator<__bitset, false>            iterator;
+    typedef __bit_iterator<__bitset, true>             const_iterator;
+
+    _LIBCPP_CONSTEXPR __bitset() _NOEXCEPT;
+    explicit _LIBCPP_CONSTEXPR __bitset(unsigned long long) _NOEXCEPT;
+
+    _LIBCPP_INLINE_VISIBILITY reference __make_ref(size_t) _NOEXCEPT
+        {return reference(0, 1);}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR const_reference __make_ref(size_t) const _NOEXCEPT
+        {return const_reference(0, 1);}
+    _LIBCPP_INLINE_VISIBILITY iterator __make_iter(size_t) _NOEXCEPT
+        {return iterator(0, 0);}
+    _LIBCPP_INLINE_VISIBILITY const_iterator __make_iter(size_t) const _NOEXCEPT
+        {return const_iterator(0, 0);}
+
+    _LIBCPP_INLINE_VISIBILITY void operator&=(const __bitset&) _NOEXCEPT {}
+    _LIBCPP_INLINE_VISIBILITY void operator|=(const __bitset&) _NOEXCEPT {}
+    _LIBCPP_INLINE_VISIBILITY void operator^=(const __bitset&) _NOEXCEPT {}
+
+    _LIBCPP_INLINE_VISIBILITY void flip() _NOEXCEPT {}
+
+    _LIBCPP_INLINE_VISIBILITY unsigned long to_ulong() const {return 0;}
+    _LIBCPP_INLINE_VISIBILITY unsigned long long to_ullong() const {return 0;}
+
+    _LIBCPP_INLINE_VISIBILITY bool all() const _NOEXCEPT {return true;}
+    _LIBCPP_INLINE_VISIBILITY bool any() const _NOEXCEPT {return false;}
+
+    _LIBCPP_INLINE_VISIBILITY size_t __hash_code() const _NOEXCEPT {return 0;}
+};
+
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+__bitset<0, 0>::__bitset() _NOEXCEPT
+{
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+__bitset<0, 0>::__bitset(unsigned long long) _NOEXCEPT
+{
+}
+
+template <size_t _Size> class _LIBCPP_TYPE_VIS_ONLY bitset;
+template <size_t _Size> struct _LIBCPP_TYPE_VIS_ONLY hash<bitset<_Size> >;
+
+template <size_t _Size>
+class _LIBCPP_TYPE_VIS_ONLY bitset
+    : private __bitset<_Size == 0 ? 0 : (_Size - 1) / (sizeof(size_t) * CHAR_BIT) + 1, _Size>
+{
+public:
+    static const unsigned __n_words = _Size == 0 ? 0 : (_Size - 1) / (sizeof(size_t) * CHAR_BIT) + 1;
+    typedef __bitset<__n_words, _Size> base;
+
+public:
+    typedef typename base::reference       reference;
+    typedef typename base::const_reference const_reference;
+
+    // 23.3.5.1 constructors:
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR bitset() _NOEXCEPT {}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+        bitset(unsigned long long __v) _NOEXCEPT : base(__v) {}
+    template<class _CharT>
+        explicit bitset(const _CharT* __str,
+                        typename basic_string<_CharT>::size_type __n = basic_string<_CharT>::npos,
+                        _CharT __zero = _CharT('0'), _CharT __one = _CharT('1'));
+    template<class _CharT, class _Traits, class _Allocator>
+        explicit bitset(const basic_string<_CharT,_Traits,_Allocator>& __str,
+                        typename basic_string<_CharT,_Traits,_Allocator>::size_type __pos = 0,
+                        typename basic_string<_CharT,_Traits,_Allocator>::size_type __n =
+                                (basic_string<_CharT,_Traits,_Allocator>::npos),
+                        _CharT __zero = _CharT('0'), _CharT __one = _CharT('1'));
+
+    // 23.3.5.2 bitset operations:
+    bitset& operator&=(const bitset& __rhs) _NOEXCEPT;
+    bitset& operator|=(const bitset& __rhs) _NOEXCEPT;
+    bitset& operator^=(const bitset& __rhs) _NOEXCEPT;
+    bitset& operator<<=(size_t __pos) _NOEXCEPT;
+    bitset& operator>>=(size_t __pos) _NOEXCEPT;
+    bitset& set() _NOEXCEPT;
+    bitset& set(size_t __pos, bool __val = true);
+    bitset& reset() _NOEXCEPT;
+    bitset& reset(size_t __pos);
+    bitset  operator~() const _NOEXCEPT;
+    bitset& flip() _NOEXCEPT;
+    bitset& flip(size_t __pos);
+
+    // element access:
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+                              const_reference operator[](size_t __p) const {return base::__make_ref(__p);}
+    _LIBCPP_INLINE_VISIBILITY       reference operator[](size_t __p)       {return base::__make_ref(__p);}
+    unsigned long to_ulong() const;
+    unsigned long long to_ullong() const;
+    template <class _CharT, class _Traits, class _Allocator>
+        basic_string<_CharT, _Traits, _Allocator> to_string(_CharT __zero = _CharT('0'),
+                                                            _CharT __one = _CharT('1')) const;
+    template <class _CharT, class _Traits>
+        basic_string<_CharT, _Traits, allocator<_CharT> > to_string(_CharT __zero = _CharT('0'),
+                                                                    _CharT __one = _CharT('1')) const;
+    template <class _CharT>
+        basic_string<_CharT, char_traits<_CharT>, allocator<_CharT> > to_string(_CharT __zero = _CharT('0'),
+                                                                                _CharT __one = _CharT('1')) const;
+    basic_string<char, char_traits<char>, allocator<char> > to_string(char __zero = '0',
+                                                                      char __one = '1') const;
+    size_t count() const _NOEXCEPT;
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR size_t size() const _NOEXCEPT {return _Size;}
+    bool operator==(const bitset& __rhs) const _NOEXCEPT;
+    bool operator!=(const bitset& __rhs) const _NOEXCEPT;
+    bool test(size_t __pos) const;
+    bool all() const _NOEXCEPT;
+    bool any() const _NOEXCEPT;
+    _LIBCPP_INLINE_VISIBILITY bool none() const _NOEXCEPT {return !any();}
+    bitset operator<<(size_t __pos) const _NOEXCEPT;
+    bitset operator>>(size_t __pos) const _NOEXCEPT;
+
+private:
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_t __hash_code() const _NOEXCEPT {return base::__hash_code();}
+
+    friend struct hash<bitset>;
+};
+
+template <size_t _Size>
+template<class _CharT>
+bitset<_Size>::bitset(const _CharT* __str,
+                      typename basic_string<_CharT>::size_type __n,
+                      _CharT __zero, _CharT __one)
+{
+    size_t __rlen = _VSTD::min(__n, char_traits<_CharT>::length(__str));
+    for (size_t __i = 0; __i < __rlen; ++__i)
+        if (__str[__i] != __zero && __str[__i] != __one)
+#ifndef _LIBCPP_NO_EXCEPTIONS
+            throw invalid_argument("bitset string ctor has invalid argument");
+#else
+            assert(!"bitset string ctor has invalid argument");
+#endif
+    size_t _Mp = _VSTD::min(__rlen, _Size);
+    size_t __i = 0;
+    for (; __i < _Mp; ++__i)
+    {
+        _CharT __c = __str[_Mp - 1 - __i];
+        if (__c == __zero)
+            (*this)[__i] = false;
+        else
+            (*this)[__i] = true;
+    }
+    _VSTD::fill(base::__make_iter(__i), base::__make_iter(_Size), false);
+}
+
+template <size_t _Size>
+template<class _CharT, class _Traits, class _Allocator>
+bitset<_Size>::bitset(const basic_string<_CharT,_Traits,_Allocator>& __str,
+       typename basic_string<_CharT,_Traits,_Allocator>::size_type __pos,
+       typename basic_string<_CharT,_Traits,_Allocator>::size_type __n,
+       _CharT __zero, _CharT __one)
+{
+    if (__pos > __str.size())
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        throw out_of_range("bitset string pos out of range");
+#else
+        assert(!"bitset string pos out of range");
+#endif
+    size_t __rlen = _VSTD::min(__n, __str.size() - __pos);
+    for (size_t __i = __pos; __i < __pos + __rlen; ++__i)
+        if (!_Traits::eq(__str[__i], __zero) && !_Traits::eq(__str[__i], __one))
+#ifndef _LIBCPP_NO_EXCEPTIONS
+            throw invalid_argument("bitset string ctor has invalid argument");
+#else
+            assert(!"bitset string ctor has invalid argument");
+#endif
+    size_t _Mp = _VSTD::min(__rlen, _Size);
+    size_t __i = 0;
+    for (; __i < _Mp; ++__i)
+    {
+        _CharT __c = __str[__pos + _Mp - 1 - __i];
+        if (_Traits::eq(__c, __zero))
+            (*this)[__i] = false;
+        else
+            (*this)[__i] = true;
+    }
+    _VSTD::fill(base::__make_iter(__i), base::__make_iter(_Size), false);
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bitset<_Size>&
+bitset<_Size>::operator&=(const bitset& __rhs) _NOEXCEPT
+{
+    base::operator&=(__rhs);
+    return *this;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bitset<_Size>&
+bitset<_Size>::operator|=(const bitset& __rhs) _NOEXCEPT
+{
+    base::operator|=(__rhs);
+    return *this;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bitset<_Size>&
+bitset<_Size>::operator^=(const bitset& __rhs) _NOEXCEPT
+{
+    base::operator^=(__rhs);
+    return *this;
+}
+
+template <size_t _Size>
+bitset<_Size>&
+bitset<_Size>::operator<<=(size_t __pos) _NOEXCEPT
+{
+    __pos = _VSTD::min(__pos, _Size);
+    _VSTD::copy_backward(base::__make_iter(0), base::__make_iter(_Size - __pos), base::__make_iter(_Size));
+    _VSTD::fill_n(base::__make_iter(0), __pos, false);
+    return *this;
+}
+
+template <size_t _Size>
+bitset<_Size>&
+bitset<_Size>::operator>>=(size_t __pos) _NOEXCEPT
+{
+    __pos = _VSTD::min(__pos, _Size);
+    _VSTD::copy(base::__make_iter(__pos), base::__make_iter(_Size), base::__make_iter(0));
+    _VSTD::fill_n(base::__make_iter(_Size - __pos), __pos, false);
+    return *this;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bitset<_Size>&
+bitset<_Size>::set() _NOEXCEPT
+{
+    _VSTD::fill_n(base::__make_iter(0), _Size, true);
+    return *this;
+}
+
+template <size_t _Size>
+bitset<_Size>&
+bitset<_Size>::set(size_t __pos, bool __val)
+{
+    if (__pos >= _Size)
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        throw out_of_range("bitset set argument out of range");
+#else
+        assert(!"bitset set argument out of range");
+#endif
+    (*this)[__pos] = __val;
+    return *this;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bitset<_Size>&
+bitset<_Size>::reset() _NOEXCEPT
+{
+    _VSTD::fill_n(base::__make_iter(0), _Size, false);
+    return *this;
+}
+
+template <size_t _Size>
+bitset<_Size>&
+bitset<_Size>::reset(size_t __pos)
+{
+    if (__pos >= _Size)
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        throw out_of_range("bitset reset argument out of range");
+#else
+        assert(!"bitset reset argument out of range");
+#endif
+    (*this)[__pos] = false;
+    return *this;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bitset<_Size>
+bitset<_Size>::operator~() const _NOEXCEPT
+{
+    bitset __x(*this);
+    __x.flip();
+    return __x;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bitset<_Size>&
+bitset<_Size>::flip() _NOEXCEPT
+{
+    base::flip();
+    return *this;
+}
+
+template <size_t _Size>
+bitset<_Size>&
+bitset<_Size>::flip(size_t __pos)
+{
+    if (__pos >= _Size)
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        throw out_of_range("bitset flip argument out of range");
+#else
+        assert(!"bitset flip argument out of range");
+#endif
+    reference r = base::__make_ref(__pos);
+    r = ~r;
+    return *this;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+unsigned long
+bitset<_Size>::to_ulong() const
+{
+    return base::to_ulong();
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+unsigned long long
+bitset<_Size>::to_ullong() const
+{
+    return base::to_ullong();
+}
+
+template <size_t _Size>
+template <class _CharT, class _Traits, class _Allocator>
+basic_string<_CharT, _Traits, _Allocator>
+bitset<_Size>::to_string(_CharT __zero, _CharT __one) const
+{
+    basic_string<_CharT, _Traits, _Allocator> __r(_Size, __zero);
+    for (size_t __i = 0; __i < _Size; ++__i)
+    {
+        if ((*this)[__i])
+            __r[_Size - 1 - __i] = __one;
+    }
+    return __r;
+}
+
+template <size_t _Size>
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_string<_CharT, _Traits, allocator<_CharT> >
+bitset<_Size>::to_string(_CharT __zero, _CharT __one) const
+{
+    return to_string<_CharT, _Traits, allocator<_CharT> >(__zero, __one);
+}
+
+template <size_t _Size>
+template <class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_string<_CharT, char_traits<_CharT>, allocator<_CharT> >
+bitset<_Size>::to_string(_CharT __zero, _CharT __one) const
+{
+    return to_string<_CharT, char_traits<_CharT>, allocator<_CharT> >(__zero, __one);
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_string<char, char_traits<char>, allocator<char> >
+bitset<_Size>::to_string(char __zero, char __one) const
+{
+    return to_string<char, char_traits<char>, allocator<char> >(__zero, __one);
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+size_t
+bitset<_Size>::count() const _NOEXCEPT
+{
+    return static_cast<size_t>(_VSTD::count(base::__make_iter(0), base::__make_iter(_Size), true));
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+bitset<_Size>::operator==(const bitset& __rhs) const _NOEXCEPT
+{
+    return _VSTD::equal(base::__make_iter(0), base::__make_iter(_Size), __rhs.__make_iter(0));
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+bitset<_Size>::operator!=(const bitset& __rhs) const _NOEXCEPT
+{
+    return !(*this == __rhs);
+}
+
+template <size_t _Size>
+bool
+bitset<_Size>::test(size_t __pos) const
+{
+    if (__pos >= _Size)
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        throw out_of_range("bitset test argument out of range");
+#else
+        assert(!"bitset test argument out of range");
+#endif
+    return (*this)[__pos];
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+bitset<_Size>::all() const _NOEXCEPT
+{
+    return base::all();
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+bitset<_Size>::any() const _NOEXCEPT
+{
+    return base::any();
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bitset<_Size>
+bitset<_Size>::operator<<(size_t __pos) const _NOEXCEPT
+{
+    bitset __r = *this;
+    __r <<= __pos;
+    return __r;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bitset<_Size>
+bitset<_Size>::operator>>(size_t __pos) const _NOEXCEPT
+{
+    bitset __r = *this;
+    __r >>= __pos;
+    return __r;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bitset<_Size>
+operator&(const bitset<_Size>& __x, const bitset<_Size>& __y) _NOEXCEPT
+{
+    bitset<_Size> __r = __x;
+    __r &= __y;
+    return __r;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bitset<_Size>
+operator|(const bitset<_Size>& __x, const bitset<_Size>& __y) _NOEXCEPT
+{
+    bitset<_Size> __r = __x;
+    __r |= __y;
+    return __r;
+}
+
+template <size_t _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+bitset<_Size>
+operator^(const bitset<_Size>& __x, const bitset<_Size>& __y) _NOEXCEPT
+{
+    bitset<_Size> __r = __x;
+    __r ^= __y;
+    return __r;
+}
+
+template <size_t _Size>
+struct _LIBCPP_TYPE_VIS_ONLY hash<bitset<_Size> >
+    : public unary_function<bitset<_Size>, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(const bitset<_Size>& __bs) const _NOEXCEPT
+        {return __bs.__hash_code();}
+};
+
+template <class _CharT, class _Traits, size_t _Size>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is, bitset<_Size>& __x);
+
+template <class _CharT, class _Traits, size_t _Size>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os, const bitset<_Size>& __x);
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_BITSET

diff --git a/libcxx/include/cassert b/libcxx/include/cassert
new file mode 100644
index 0000000..3775990
--- /dev/null
+++ b/libcxx/include/cassert

@@ -0,0 +1,25 @@
+// -*- C++ -*-
+//===-------------------------- cassert -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+/*
+    cassert synopsis
+
+Macros:
+
+    assert
+
+*/
+
+#include <__config>
+#include <assert.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif

diff --git a/libcxx/include/ccomplex b/libcxx/include/ccomplex
new file mode 100644
index 0000000..6ed1164
--- /dev/null
+++ b/libcxx/include/ccomplex

@@ -0,0 +1,29 @@
+// -*- C++ -*-
+//===--------------------------- ccomplex ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CCOMPLEX
+#define _LIBCPP_CCOMPLEX
+
+/*
+    ccomplex synopsis
+
+#include <complex>
+
+*/
+
+#include <complex>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+// hh 080623 Created
+
+#endif  // _LIBCPP_CCOMPLEX

diff --git a/libcxx/include/cctype b/libcxx/include/cctype
new file mode 100644
index 0000000..26c740f
--- /dev/null
+++ b/libcxx/include/cctype

@@ -0,0 +1,165 @@
+// -*- C++ -*-
+//===---------------------------- cctype ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CCTYPE
+#define _LIBCPP_CCTYPE
+
+/*
+    cctype synopsis
+
+namespace std
+{
+
+int isalnum(int c);
+int isalpha(int c);
+int isblank(int c);  // C99
+int iscntrl(int c);
+int isdigit(int c);
+int isgraph(int c);
+int islower(int c);
+int isprint(int c);
+int ispunct(int c);
+int isspace(int c);
+int isupper(int c);
+int isxdigit(int c);
+int tolower(int c);
+int toupper(int c);
+
+}  // std
+*/
+
+#include <__config>
+#include <ctype.h>
+#if defined(_LIBCPP_MSVCRT)
+#include "support/win32/support.h"
+#include "support/win32/locale_win32.h"
+#endif // _LIBCPP_MSVCRT
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#ifdef isalnum
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_isalnum(int __c) {return isalnum(__c);}
+#undef isalnum
+inline _LIBCPP_INLINE_VISIBILITY int isalnum(int __c) {return __libcpp_isalnum(__c);}
+#else  // isalnum
+using ::isalnum;
+#endif  // isalnum
+
+#ifdef isalpha
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_isalpha(int __c) {return isalpha(__c);}
+#undef isalpha
+inline _LIBCPP_INLINE_VISIBILITY int isalpha(int __c) {return __libcpp_isalpha(__c);}
+#else  // isalpha
+using ::isalpha;
+#endif  // isalpha
+
+#ifdef isblank
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_isblank(int __c) {return isblank(__c);}
+#undef isblank
+inline _LIBCPP_INLINE_VISIBILITY int isblank(int __c) {return __libcpp_isblank(__c);}
+#else  // isblank
+using ::isblank;
+#endif  // isblank
+
+#ifdef iscntrl
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_iscntrl(int __c) {return iscntrl(__c);}
+#undef iscntrl
+inline _LIBCPP_INLINE_VISIBILITY int iscntrl(int __c) {return __libcpp_iscntrl(__c);}
+#else  // iscntrl
+using ::iscntrl;
+#endif  // iscntrl
+
+#ifdef isdigit
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_isdigit(int __c) {return isdigit(__c);}
+#undef isdigit
+inline _LIBCPP_INLINE_VISIBILITY int isdigit(int __c) {return __libcpp_isdigit(__c);}
+#else  // isdigit
+using ::isdigit;
+#endif  // isdigit
+
+#ifdef isgraph
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_isgraph(int __c) {return isgraph(__c);}
+#undef isgraph
+inline _LIBCPP_INLINE_VISIBILITY int isgraph(int __c) {return __libcpp_isgraph(__c);}
+#else  // isgraph
+using ::isgraph;
+#endif  // isgraph
+
+#ifdef islower
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_islower(int __c) {return islower(__c);}
+#undef islower
+inline _LIBCPP_INLINE_VISIBILITY int islower(int __c) {return __libcpp_islower(__c);}
+#else  // islower
+using ::islower;
+#endif  // islower
+
+#ifdef isprint
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_isprint(int __c) {return isprint(__c);}
+#undef isprint
+inline _LIBCPP_INLINE_VISIBILITY int isprint(int __c) {return __libcpp_isprint(__c);}
+#else  // isprint
+using ::isprint;
+#endif  // isprint
+
+#ifdef ispunct
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_ispunct(int __c) {return ispunct(__c);}
+#undef ispunct
+inline _LIBCPP_INLINE_VISIBILITY int ispunct(int __c) {return __libcpp_ispunct(__c);}
+#else  // ispunct
+using ::ispunct;
+#endif  // ispunct
+
+#ifdef isspace
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_isspace(int __c) {return isspace(__c);}
+#undef isspace
+inline _LIBCPP_INLINE_VISIBILITY int isspace(int __c) {return __libcpp_isspace(__c);}
+#else  // isspace
+using ::isspace;
+#endif  // isspace
+
+#ifdef isupper
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_isupper(int __c) {return isupper(__c);}
+#undef isupper
+inline _LIBCPP_INLINE_VISIBILITY int isupper(int __c) {return __libcpp_isupper(__c);}
+#else  // isupper
+using ::isupper;
+#endif  // isupper
+
+#ifdef isxdigit
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_isxdigit(int __c) {return isxdigit(__c);}
+#undef isxdigit
+inline _LIBCPP_INLINE_VISIBILITY int isxdigit(int __c) {return __libcpp_isxdigit(__c);}
+#else  // isxdigit
+using ::isxdigit;
+#endif  // isxdigit
+
+#ifdef tolower
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_tolower(int __c) {return tolower(__c);}
+#undef tolower
+inline _LIBCPP_INLINE_VISIBILITY int tolower(int __c) {return __libcpp_tolower(__c);}
+#else  // tolower
+using ::tolower;
+#endif  // tolower
+
+#ifdef toupper
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_toupper(int __c) {return toupper(__c);}
+#undef toupper
+inline _LIBCPP_INLINE_VISIBILITY int toupper(int __c) {return __libcpp_toupper(__c);}
+#else  // toupper
+using ::toupper;
+#endif  // toupper
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CCTYPE

diff --git a/libcxx/include/cerrno b/libcxx/include/cerrno
new file mode 100644
index 0000000..9804e4e
--- /dev/null
+++ b/libcxx/include/cerrno

@@ -0,0 +1,393 @@
+// -*- C++ -*-
+//===-------------------------- cerrno ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CERRNO
+#define _LIBCPP_CERRNO
+
+/*
+    cerrno synopsis
+
+Macros:
+
+    EDOM
+    EILSEQ  // C99
+    ERANGE
+    errno
+
+*/
+
+#include <__config>
+#include <errno.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#if !defined(EOWNERDEAD) || !defined(ENOTRECOVERABLE)
+
+#ifdef ELAST
+
+const int __elast1 = ELAST+1;
+const int __elast2 = ELAST+2;
+
+#else
+
+const int __elast1 = 104;
+const int __elast2 = 105;
+
+#endif
+
+#ifdef ENOTRECOVERABLE
+
+#define EOWNERDEAD __elast1
+
+#ifdef ELAST
+#undef ELAST
+#define ELAST EOWNERDEAD
+#endif
+
+#elif defined(EOWNERDEAD)
+
+#define ENOTRECOVERABLE __elast1
+#ifdef ELAST
+#undef ELAST
+#define ELAST ENOTRECOVERABLE
+#endif
+
+#else  // defined(EOWNERDEAD)
+
+#define EOWNERDEAD __elast1
+#define ENOTRECOVERABLE __elast2
+#ifdef ELAST
+#undef ELAST
+#define ELAST ENOTRECOVERABLE
+#endif
+
+#endif  // defined(EOWNERDEAD)
+
+#endif  // !defined(EOWNERDEAD) || !defined(ENOTRECOVERABLE)
+
+//  supply errno values likely to be missing, particularly on Windows
+
+#ifndef EAFNOSUPPORT
+#define EAFNOSUPPORT 9901
+#endif
+
+#ifndef EADDRINUSE
+#define EADDRINUSE 9902
+#endif
+
+#ifndef EADDRNOTAVAIL
+#define EADDRNOTAVAIL 9903
+#endif
+
+#ifndef EISCONN
+#define EISCONN 9904
+#endif
+
+#ifndef EBADMSG
+#define EBADMSG 9905
+#endif
+
+#ifndef ECONNABORTED
+#define ECONNABORTED 9906
+#endif
+
+#ifndef EALREADY
+#define EALREADY 9907
+#endif
+
+#ifndef ECONNREFUSED
+#define ECONNREFUSED 9908
+#endif
+
+#ifndef ECONNRESET
+#define ECONNRESET 9909
+#endif
+
+#ifndef EDESTADDRREQ
+#define EDESTADDRREQ 9910
+#endif
+
+#ifndef EHOSTUNREACH
+#define EHOSTUNREACH 9911
+#endif
+
+#ifndef EIDRM
+#define EIDRM 9912
+#endif
+
+#ifndef EMSGSIZE
+#define EMSGSIZE 9913
+#endif
+
+#ifndef ENETDOWN
+#define ENETDOWN 9914
+#endif
+
+#ifndef ENETRESET
+#define ENETRESET 9915
+#endif
+
+#ifndef ENETUNREACH
+#define ENETUNREACH 9916
+#endif
+
+#ifndef ENOBUFS
+#define ENOBUFS 9917
+#endif
+
+#ifndef ENOLINK
+#define ENOLINK 9918
+#endif
+
+#ifndef ENODATA
+#define ENODATA 9919
+#endif
+
+#ifndef ENOMSG
+#define ENOMSG 9920
+#endif
+
+#ifndef ENOPROTOOPT
+#define ENOPROTOOPT 9921
+#endif
+
+#ifndef ENOSR
+#define ENOSR 9922
+#endif
+
+#ifndef ENOTSOCK
+#define ENOTSOCK 9923
+#endif
+
+#ifndef ENOSTR
+#define ENOSTR 9924
+#endif
+
+#ifndef ENOTCONN
+#define ENOTCONN 9925
+#endif
+
+#ifndef ENOTSUP
+#define ENOTSUP 9926
+#endif
+
+#ifndef ECANCELED
+#define ECANCELED 9927
+#endif
+
+#ifndef EINPROGRESS
+#define EINPROGRESS 9928
+#endif
+
+#ifndef EOPNOTSUPP
+#define EOPNOTSUPP 9929
+#endif
+
+#ifndef EWOULDBLOCK
+#define EWOULDBLOCK 9930
+#endif
+
+#ifndef EOWNERDEAD
+#define EOWNERDEAD  9931
+#endif
+
+#ifndef EPROTO
+#define EPROTO 9932
+#endif
+
+#ifndef EPROTONOSUPPORT
+#define EPROTONOSUPPORT 9933
+#endif
+
+#ifndef ENOTRECOVERABLE
+#define ENOTRECOVERABLE 9934
+#endif
+
+#ifndef ETIME
+#define ETIME 9935
+#endif
+
+#ifndef ETXTBSY
+#define ETXTBSY 9936
+#endif
+
+#ifndef ETIMEDOUT
+#define ETIMEDOUT 9938
+#endif
+
+#ifndef ELOOP
+#define ELOOP 9939
+#endif
+
+#ifndef EOVERFLOW
+#define EOVERFLOW 9940
+#endif
+
+#ifndef EPROTOTYPE
+#define EPROTOTYPE 9941
+#endif
+
+#ifndef ENOSYS
+#define ENOSYS 9942
+#endif
+
+#ifndef EINVAL
+#define EINVAL 9943
+#endif
+
+#ifndef ERANGE
+#define ERANGE 9944
+#endif
+
+#ifndef EILSEQ
+#define EILSEQ 9945
+#endif
+
+//  Windows Mobile doesn't appear to define these:
+
+#ifndef E2BIG
+#define E2BIG 9946
+#endif
+
+#ifndef EDOM
+#define EDOM 9947
+#endif
+
+#ifndef EFAULT
+#define EFAULT 9948
+#endif
+
+#ifndef EBADF
+#define EBADF 9949
+#endif
+
+#ifndef EPIPE
+#define EPIPE 9950
+#endif
+
+#ifndef EXDEV
+#define EXDEV 9951
+#endif
+
+#ifndef EBUSY
+#define EBUSY 9952
+#endif
+
+#ifndef ENOTEMPTY
+#define ENOTEMPTY 9953
+#endif
+
+#ifndef ENOEXEC
+#define ENOEXEC 9954
+#endif
+
+#ifndef EEXIST
+#define EEXIST 9955
+#endif
+
+#ifndef EFBIG
+#define EFBIG 9956
+#endif
+
+#ifndef ENAMETOOLONG
+#define ENAMETOOLONG 9957
+#endif
+
+#ifndef ENOTTY
+#define ENOTTY 9958
+#endif
+
+#ifndef EINTR
+#define EINTR 9959
+#endif
+
+#ifndef ESPIPE
+#define ESPIPE 9960
+#endif
+
+#ifndef EIO
+#define EIO 9961
+#endif
+
+#ifndef EISDIR
+#define EISDIR 9962
+#endif
+
+#ifndef ECHILD
+#define ECHILD 9963
+#endif
+
+#ifndef ENOLCK
+#define ENOLCK 9964
+#endif
+
+#ifndef ENOSPC
+#define ENOSPC 9965
+#endif
+
+#ifndef ENXIO
+#define ENXIO 9966
+#endif
+
+#ifndef ENODEV
+#define ENODEV 9967
+#endif
+
+#ifndef ENOENT
+#define ENOENT 9968
+#endif
+
+#ifndef ESRCH
+#define ESRCH 9969
+#endif
+
+#ifndef ENOTDIR
+#define ENOTDIR 9970
+#endif
+
+#ifndef ENOMEM
+#define ENOMEM 9971
+#endif
+
+#ifndef EPERM
+#define EPERM 9972
+#endif
+
+#ifndef EACCES
+#define EACCES 9973
+#endif
+
+#ifndef EROFS
+#define EROFS 9974
+#endif
+
+#ifndef EDEADLK
+#define EDEADLK 9975
+#endif
+
+#ifndef EAGAIN
+#define EAGAIN 9976
+#endif
+
+#ifndef ENFILE
+#define ENFILE 9977
+#endif
+
+#ifndef EMFILE
+#define EMFILE 9978
+#endif
+
+#ifndef EMLINK
+#define EMLINK 9979
+#endif
+
+#endif  // _LIBCPP_CERRNO

diff --git a/libcxx/include/cfenv b/libcxx/include/cfenv
new file mode 100644
index 0000000..dd7db37
--- /dev/null
+++ b/libcxx/include/cfenv

@@ -0,0 +1,82 @@
+// -*- C++ -*-
+//===---------------------------- cctype ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CFENV
+#define _LIBCPP_CFENV
+
+/*
+    cfenv synopsis
+
+This entire header is C99 / C++0X
+
+Macros:
+
+    FE_DIVBYZERO
+    FE_INEXACT
+    FE_INVALID
+    FE_OVERFLOW
+    FE_UNDERFLOW
+    FE_ALL_EXCEPT
+    FE_DOWNWARD
+    FE_TONEAREST
+    FE_TOWARDZERO
+    FE_UPWARD
+    FE_DFL_ENV
+
+namespace std
+{
+
+Types:
+
+    fenv_t
+    fexcept_t
+
+int feclearexcept(int excepts);
+int fegetexceptflag(fexcept_t* flagp, int excepts);
+int feraiseexcept(int excepts);
+int fesetexceptflag(const fexcept_t* flagp, int excepts);
+int fetestexcept(int excepts);
+int fegetround();
+int fesetround(int round);
+int fegetenv(fenv_t* envp);
+int feholdexcept(fenv_t* envp);
+int fesetenv(const fenv_t* envp);
+int feupdateenv(const fenv_t* envp);
+
+}  // std
+*/
+
+#include <__config>
+#include <fenv.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+using ::fenv_t;
+using ::fexcept_t;
+
+using ::feclearexcept;
+using ::fegetexceptflag;
+using ::feraiseexcept;
+using ::fesetexceptflag;
+using ::fetestexcept;
+using ::fegetround;
+using ::fesetround;
+using ::fegetenv;
+using ::feholdexcept;
+using ::fesetenv;
+using ::feupdateenv;
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CFENV

diff --git a/libcxx/include/cfloat b/libcxx/include/cfloat
new file mode 100644
index 0000000..5fa5655
--- /dev/null
+++ b/libcxx/include/cfloat

@@ -0,0 +1,78 @@
+// -*- C++ -*-
+//===--------------------------- cfloat -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CFLOAT
+#define _LIBCPP_CFLOAT
+
+/*
+    cfloat synopsis
+
+Macros:
+
+    FLT_ROUNDS
+    FLT_EVAL_METHOD     // C99
+    FLT_RADIX
+
+    FLT_MANT_DIG
+    DBL_MANT_DIG
+    LDBL_MANT_DIG
+
+    DECIMAL_DIG         // C99
+
+    FLT_DIG
+    DBL_DIG
+    LDBL_DIG
+
+    FLT_MIN_EXP
+    DBL_MIN_EXP
+    LDBL_MIN_EXP
+
+    FLT_MIN_10_EXP
+    DBL_MIN_10_EXP
+    LDBL_MIN_10_EXP
+
+    FLT_MAX_EXP
+    DBL_MAX_EXP
+    LDBL_MAX_EXP
+
+    FLT_MAX_10_EXP
+    DBL_MAX_10_EXP
+    LDBL_MAX_10_EXP
+
+    FLT_MAX
+    DBL_MAX
+    LDBL_MAX
+
+    FLT_EPSILON
+    DBL_EPSILON
+    LDBL_EPSILON
+
+    FLT_MIN
+    DBL_MIN
+    LDBL_MIN
+
+*/
+
+#include <__config>
+#include <float.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#ifndef FLT_EVAL_METHOD
+#define FLT_EVAL_METHOD __FLT_EVAL_METHOD__
+#endif
+
+#ifndef DECIMAL_DIG
+#define DECIMAL_DIG __DECIMAL_DIG__
+#endif
+
+#endif  // _LIBCPP_CFLOAT

diff --git a/libcxx/include/chrono b/libcxx/include/chrono
new file mode 100644
index 0000000..9229234
--- /dev/null
+++ b/libcxx/include/chrono

@@ -0,0 +1,1031 @@
+// -*- C++ -*-
+//===---------------------------- chrono ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CHRONO
+#define _LIBCPP_CHRONO
+
+/*
+    chrono synopsis
+
+namespace std
+{
+namespace chrono
+{
+
+template <class ToDuration, class Rep, class Period>
+constexpr
+ToDuration
+duration_cast(const duration<Rep, Period>& fd);
+
+template <class Rep> struct treat_as_floating_point : is_floating_point<Rep> {};
+
+template <class Rep>
+struct duration_values
+{
+public:
+    static constexpr Rep zero();
+    static constexpr Rep max();
+    static constexpr Rep min();
+};
+
+// duration
+
+template <class Rep, class Period = ratio<1>>
+class duration
+{
+    static_assert(!__is_duration<Rep>::value, "A duration representation can not be a duration");
+    static_assert(__is_ratio<Period>::value, "Second template parameter of duration must be a std::ratio");
+    static_assert(Period::num > 0, "duration period must be positive");
+public:
+    typedef Rep rep;
+    typedef Period period;
+
+    constexpr duration() = default;
+    template <class Rep2>
+        constexpr explicit duration(const Rep2& r,
+            typename enable_if
+            <
+               is_convertible<Rep2, rep>::value &&
+               (treat_as_floating_point<rep>::value ||
+               !treat_as_floating_point<rep>::value && !treat_as_floating_point<Rep2>::value)
+            >::type* = 0);
+
+    // conversions
+    template <class Rep2, class Period2>
+        constexpr duration(const duration<Rep2, Period2>& d,
+            typename enable_if
+            <
+                treat_as_floating_point<rep>::value ||
+                ratio_divide<Period2, period>::type::den == 1
+            >::type* = 0);
+
+    // observer
+
+    constexpr rep count() const;
+
+    // arithmetic
+
+    constexpr duration  operator+() const;
+    constexpr duration  operator-() const;
+    duration& operator++();
+    duration  operator++(int);
+    duration& operator--();
+    duration  operator--(int);
+
+    duration& operator+=(const duration& d);
+    duration& operator-=(const duration& d);
+
+    duration& operator*=(const rep& rhs);
+    duration& operator/=(const rep& rhs);
+
+    // special values
+
+    static constexpr duration zero();
+    static constexpr duration min();
+    static constexpr duration max();
+};
+
+typedef duration<long long,         nano> nanoseconds;
+typedef duration<long long,        micro> microseconds;
+typedef duration<long long,        milli> milliseconds;
+typedef duration<long long              > seconds;
+typedef duration<     long, ratio<  60> > minutes;
+typedef duration<     long, ratio<3600> > hours;
+
+template <class Clock, class Duration = typename Clock::duration>
+class time_point
+{
+public:
+    typedef Clock                     clock;
+    typedef Duration                  duration;
+    typedef typename duration::rep    rep;
+    typedef typename duration::period period;
+private:
+    duration d_;  // exposition only
+
+public:
+    time_point();  // has value "epoch" // constexpr in C++14
+    explicit time_point(const duration& d);  // same as time_point() + d // constexpr in C++14
+
+    // conversions
+    template <class Duration2>
+       time_point(const time_point<clock, Duration2>& t); // constexpr in C++14
+
+    // observer
+
+    duration time_since_epoch() const; // constexpr in C++14
+
+    // arithmetic
+
+    time_point& operator+=(const duration& d);
+    time_point& operator-=(const duration& d);
+
+    // special values
+
+    static constexpr time_point min();
+    static constexpr time_point max();
+};
+
+} // chrono
+
+// common_type traits
+template <class Rep1, class Period1, class Rep2, class Period2>
+  struct common_type<chrono::duration<Rep1, Period1>, chrono::duration<Rep2, Period2>>;
+
+template <class Clock, class Duration1, class Duration2>
+  struct common_type<chrono::time_point<Clock, Duration1>, chrono::time_point<Clock, Duration2>>;
+
+namespace chrono {
+
+// duration arithmetic
+template <class Rep1, class Period1, class Rep2, class Period2>
+  constexpr
+  typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
+  operator+(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+template <class Rep1, class Period1, class Rep2, class Period2>
+  constexpr
+  typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
+  operator-(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+template <class Rep1, class Period, class Rep2>
+  constexpr
+  duration<typename common_type<Rep1, Rep2>::type, Period>
+  operator*(const duration<Rep1, Period>& d, const Rep2& s);
+template <class Rep1, class Period, class Rep2>
+  constexpr
+  duration<typename common_type<Rep1, Rep2>::type, Period>
+  operator*(const Rep1& s, const duration<Rep2, Period>& d);
+template <class Rep1, class Period, class Rep2>
+  constexpr
+  duration<typename common_type<Rep1, Rep2>::type, Period>
+  operator/(const duration<Rep1, Period>& d, const Rep2& s);
+template <class Rep1, class Period1, class Rep2, class Period2>
+  constexpr
+  typename common_type<Rep1, Rep2>::type
+  operator/(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+
+// duration comparisons
+template <class Rep1, class Period1, class Rep2, class Period2>
+   constexpr
+   bool operator==(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+template <class Rep1, class Period1, class Rep2, class Period2>
+   constexpr
+   bool operator!=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+template <class Rep1, class Period1, class Rep2, class Period2>
+   constexpr
+   bool operator< (const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+template <class Rep1, class Period1, class Rep2, class Period2>
+   constexpr
+   bool operator<=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+template <class Rep1, class Period1, class Rep2, class Period2>
+   constexpr
+   bool operator> (const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+template <class Rep1, class Period1, class Rep2, class Period2>
+   constexpr
+   bool operator>=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
+
+// duration_cast
+template <class ToDuration, class Rep, class Period>
+  ToDuration duration_cast(const duration<Rep, Period>& d);
+
+// time_point arithmetic (all constexpr in C++14)
+template <class Clock, class Duration1, class Rep2, class Period2>
+  time_point<Clock, typename common_type<Duration1, duration<Rep2, Period2>>::type>
+  operator+(const time_point<Clock, Duration1>& lhs, const duration<Rep2, Period2>& rhs);
+template <class Rep1, class Period1, class Clock, class Duration2>
+  time_point<Clock, typename common_type<duration<Rep1, Period1>, Duration2>::type>
+  operator+(const duration<Rep1, Period1>& lhs, const time_point<Clock, Duration2>& rhs);
+template <class Clock, class Duration1, class Rep2, class Period2>
+  time_point<Clock, typename common_type<Duration1, duration<Rep2, Period2>>::type>
+  operator-(const time_point<Clock, Duration1>& lhs, const duration<Rep2, Period2>& rhs);
+template <class Clock, class Duration1, class Duration2>
+  typename common_type<Duration1, Duration2>::type
+  operator-(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
+
+// time_point comparisons (all constexpr in C++14)
+template <class Clock, class Duration1, class Duration2>
+   bool operator==(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
+template <class Clock, class Duration1, class Duration2>
+   bool operator!=(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
+template <class Clock, class Duration1, class Duration2>
+   bool operator< (const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
+template <class Clock, class Duration1, class Duration2>
+   bool operator<=(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
+template <class Clock, class Duration1, class Duration2>
+   bool operator> (const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
+template <class Clock, class Duration1, class Duration2>
+   bool operator>=(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
+
+// time_point_cast (constexpr in C++14)
+
+template <class ToDuration, class Clock, class Duration>
+  time_point<Clock, ToDuration> time_point_cast(const time_point<Clock, Duration>& t);
+
+// Clocks
+
+class system_clock
+{
+public:
+    typedef microseconds                     duration;
+    typedef duration::rep                    rep;
+    typedef duration::period                 period;
+    typedef chrono::time_point<system_clock> time_point;
+    static const bool is_steady =            false; // constexpr in C++14
+
+    static time_point now() noexcept;
+    static time_t     to_time_t  (const time_point& __t) noexcept;
+    static time_point from_time_t(time_t __t) noexcept;
+};
+
+class steady_clock
+{
+public:
+    typedef nanoseconds                                   duration;
+    typedef duration::rep                                 rep;
+    typedef duration::period                              period;
+    typedef chrono::time_point<steady_clock, duration>    time_point;
+    static const bool is_steady =                         true; // constexpr in C++14
+
+    static time_point now() noexcept;
+};
+
+typedef steady_clock high_resolution_clock;
+
+}  // chrono
+
+constexpr chrono::hours                                 operator "" h(unsigned long long); // C++14
+constexpr chrono::duration<unspecified , ratio<3600,1>> operator "" h(long double); // C++14
+constexpr chrono::minutes                               operator "" min(unsigned long long); // C++14
+constexpr chrono::duration<unspecified , ratio<60,1>>   operator "" min(long double); // C++14
+constexpr chrono::seconds                               operator "" s(unsigned long long); // C++14
+constexpr chrono::duration<unspecified >                operator "" s(long double); // C++14
+constexpr chrono::milliseconds                          operator "" ms(unsigned long long); // C++14
+constexpr chrono::duration<unspecified , milli>         operator "" ms(long double); // C++14
+constexpr chrono::microseconds                          operator "" us(unsigned long long); // C++14
+constexpr chrono::duration<unspecified , micro>         operator "" us(long double); // C++14
+constexpr chrono::nanoseconds                           operator "" ns(unsigned long long); // C++14
+constexpr chrono::duration<unspecified , nano>          operator "" ns(long double); // C++14
+
+}  // std
+*/
+
+#include <__config>
+#include <ctime>
+#include <type_traits>
+#include <ratio>
+#include <limits>
+
+#include <__undef_min_max>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace chrono
+{
+
+template <class _Rep, class _Period = ratio<1> > class _LIBCPP_TYPE_VIS_ONLY duration;
+
+template <class _Tp>
+struct __is_duration : false_type {};
+
+template <class _Rep, class _Period>
+struct __is_duration<duration<_Rep, _Period> > : true_type  {};
+
+template <class _Rep, class _Period>
+struct __is_duration<const duration<_Rep, _Period> > : true_type  {};
+
+template <class _Rep, class _Period>
+struct __is_duration<volatile duration<_Rep, _Period> > : true_type  {};
+
+template <class _Rep, class _Period>
+struct __is_duration<const volatile duration<_Rep, _Period> > : true_type  {};
+
+} // chrono
+
+template <class _Rep1, class _Period1, class _Rep2, class _Period2>
+struct _LIBCPP_TYPE_VIS_ONLY common_type<chrono::duration<_Rep1, _Period1>,
+                                         chrono::duration<_Rep2, _Period2> >
+{
+    typedef chrono::duration<typename common_type<_Rep1, _Rep2>::type,
+                             typename __ratio_gcd<_Period1, _Period2>::type> type;
+};
+
+namespace chrono {
+
+// duration_cast
+
+template <class _FromDuration, class _ToDuration,
+          class _Period = typename ratio_divide<typename _FromDuration::period, typename _ToDuration::period>::type,
+          bool = _Period::num == 1,
+          bool = _Period::den == 1>
+struct __duration_cast;
+
+template <class _FromDuration, class _ToDuration, class _Period>
+struct __duration_cast<_FromDuration, _ToDuration, _Period, true, true>
+{
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    _ToDuration operator()(const _FromDuration& __fd) const
+    {
+        return _ToDuration(static_cast<typename _ToDuration::rep>(__fd.count()));
+    }
+};
+
+template <class _FromDuration, class _ToDuration, class _Period>
+struct __duration_cast<_FromDuration, _ToDuration, _Period, true, false>
+{
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    _ToDuration operator()(const _FromDuration& __fd) const
+    {
+        typedef typename common_type<typename _ToDuration::rep, typename _FromDuration::rep, intmax_t>::type _Ct;
+        return _ToDuration(static_cast<typename _ToDuration::rep>(
+                           static_cast<_Ct>(__fd.count()) / static_cast<_Ct>(_Period::den)));
+    }
+};
+
+template <class _FromDuration, class _ToDuration, class _Period>
+struct __duration_cast<_FromDuration, _ToDuration, _Period, false, true>
+{
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    _ToDuration operator()(const _FromDuration& __fd) const
+    {
+        typedef typename common_type<typename _ToDuration::rep, typename _FromDuration::rep, intmax_t>::type _Ct;
+        return _ToDuration(static_cast<typename _ToDuration::rep>(
+                           static_cast<_Ct>(__fd.count()) * static_cast<_Ct>(_Period::num)));
+    }
+};
+
+template <class _FromDuration, class _ToDuration, class _Period>
+struct __duration_cast<_FromDuration, _ToDuration, _Period, false, false>
+{
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    _ToDuration operator()(const _FromDuration& __fd) const
+    {
+        typedef typename common_type<typename _ToDuration::rep, typename _FromDuration::rep, intmax_t>::type _Ct;
+        return _ToDuration(static_cast<typename _ToDuration::rep>(
+                           static_cast<_Ct>(__fd.count()) * static_cast<_Ct>(_Period::num)
+                                                          / static_cast<_Ct>(_Period::den)));
+    }
+};
+
+template <class _ToDuration, class _Rep, class _Period>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+typename enable_if
+<
+    __is_duration<_ToDuration>::value,
+    _ToDuration
+>::type
+duration_cast(const duration<_Rep, _Period>& __fd)
+{
+    return __duration_cast<duration<_Rep, _Period>, _ToDuration>()(__fd);
+}
+
+template <class _Rep>
+struct _LIBCPP_TYPE_VIS_ONLY treat_as_floating_point : is_floating_point<_Rep> {};
+
+template <class _Rep>
+struct _LIBCPP_TYPE_VIS_ONLY duration_values
+{
+public:
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep zero() {return _Rep(0);}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep max()  {return numeric_limits<_Rep>::max();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep min()  {return numeric_limits<_Rep>::lowest();}
+};
+
+// duration
+
+template <class _Rep, class _Period>
+class _LIBCPP_TYPE_VIS_ONLY duration
+{
+    static_assert(!__is_duration<_Rep>::value, "A duration representation can not be a duration");
+    static_assert(__is_ratio<_Period>::value, "Second template parameter of duration must be a std::ratio");
+    static_assert(_Period::num > 0, "duration period must be positive");
+
+    template <class _R1, class _R2>
+    struct __no_overflow
+    {
+    private:
+        static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
+        static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
+        static const intmax_t __n1 = _R1::num / __gcd_n1_n2;
+        static const intmax_t __d1 = _R1::den / __gcd_d1_d2;
+        static const intmax_t __n2 = _R2::num / __gcd_n1_n2;
+        static const intmax_t __d2 = _R2::den / __gcd_d1_d2;
+        static const intmax_t max = -((intmax_t(1) << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1);
+
+        template <intmax_t _Xp, intmax_t _Yp, bool __overflow>
+        struct __mul    // __overflow == false
+        {
+            static const intmax_t value = _Xp * _Yp;
+        };
+
+        template <intmax_t _Xp, intmax_t _Yp>
+        struct __mul<_Xp, _Yp, true>
+        {
+            static const intmax_t value = 1;
+        };
+
+    public:
+        static const bool value = (__n1 <= max / __d2) && (__n2 <= max / __d1);
+        typedef ratio<__mul<__n1, __d2, !value>::value,
+                      __mul<__n2, __d1, !value>::value> type;
+    };
+    
+public:
+    typedef _Rep rep;
+    typedef _Period period;
+private:
+    rep __rep_;
+public:
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+#ifndef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+        duration() = default;
+#else
+        duration() {}
+#endif
+
+    template <class _Rep2>
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+        explicit duration(const _Rep2& __r,
+            typename enable_if
+            <
+               is_convertible<_Rep2, rep>::value &&
+               (treat_as_floating_point<rep>::value ||
+               !treat_as_floating_point<_Rep2>::value)
+            >::type* = 0)
+                : __rep_(__r) {}
+
+    // conversions
+    template <class _Rep2, class _Period2>
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+        duration(const duration<_Rep2, _Period2>& __d,
+            typename enable_if
+            <
+                __no_overflow<_Period2, period>::value && (
+                treat_as_floating_point<rep>::value ||
+                (__no_overflow<_Period2, period>::type::den == 1 &&
+                 !treat_as_floating_point<_Rep2>::value))
+            >::type* = 0)
+                : __rep_(_VSTD::chrono::duration_cast<duration>(__d).count()) {}
+
+    // observer
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR rep count() const {return __rep_;}
+
+    // arithmetic
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR duration  operator+() const {return *this;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR duration  operator-() const {return duration(-__rep_);}
+    _LIBCPP_INLINE_VISIBILITY duration& operator++()      {++__rep_; return *this;}
+    _LIBCPP_INLINE_VISIBILITY duration  operator++(int)   {return duration(__rep_++);}
+    _LIBCPP_INLINE_VISIBILITY duration& operator--()      {--__rep_; return *this;}
+    _LIBCPP_INLINE_VISIBILITY duration  operator--(int)   {return duration(__rep_--);}
+
+    _LIBCPP_INLINE_VISIBILITY duration& operator+=(const duration& __d) {__rep_ += __d.count(); return *this;}
+    _LIBCPP_INLINE_VISIBILITY duration& operator-=(const duration& __d) {__rep_ -= __d.count(); return *this;}
+
+    _LIBCPP_INLINE_VISIBILITY duration& operator*=(const rep& rhs) {__rep_ *= rhs; return *this;}
+    _LIBCPP_INLINE_VISIBILITY duration& operator/=(const rep& rhs) {__rep_ /= rhs; return *this;}
+    _LIBCPP_INLINE_VISIBILITY duration& operator%=(const rep& rhs) {__rep_ %= rhs; return *this;}
+    _LIBCPP_INLINE_VISIBILITY duration& operator%=(const duration& rhs) {__rep_ %= rhs.count(); return *this;}
+
+    // special values
+
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR duration zero() {return duration(duration_values<rep>::zero());}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR duration min()  {return duration(duration_values<rep>::min());}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR duration max()  {return duration(duration_values<rep>::max());}
+};
+
+typedef duration<long long,         nano> nanoseconds;
+typedef duration<long long,        micro> microseconds;
+typedef duration<long long,        milli> milliseconds;
+typedef duration<long long              > seconds;
+typedef duration<     long, ratio<  60> > minutes;
+typedef duration<     long, ratio<3600> > hours;
+
+// Duration ==
+
+template <class _LhsDuration, class _RhsDuration>
+struct __duration_eq
+{
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    bool operator()(const _LhsDuration& __lhs, const _RhsDuration& __rhs) const
+        {
+            typedef typename common_type<_LhsDuration, _RhsDuration>::type _Ct;
+            return _Ct(__lhs).count() == _Ct(__rhs).count();
+        }
+};
+
+template <class _LhsDuration>
+struct __duration_eq<_LhsDuration, _LhsDuration>
+{
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    bool operator()(const _LhsDuration& __lhs, const _LhsDuration& __rhs) const
+        {return __lhs.count() == __rhs.count();}
+};
+
+template <class _Rep1, class _Period1, class _Rep2, class _Period2>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+bool
+operator==(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
+{
+    return __duration_eq<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >()(__lhs, __rhs);
+}
+
+// Duration !=
+
+template <class _Rep1, class _Period1, class _Rep2, class _Period2>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+bool
+operator!=(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
+{
+    return !(__lhs == __rhs);
+}
+
+// Duration <
+
+template <class _LhsDuration, class _RhsDuration>
+struct __duration_lt
+{
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    bool operator()(const _LhsDuration& __lhs, const _RhsDuration& __rhs) const
+        {
+            typedef typename common_type<_LhsDuration, _RhsDuration>::type _Ct;
+            return _Ct(__lhs).count() < _Ct(__rhs).count();
+        }
+};
+
+template <class _LhsDuration>
+struct __duration_lt<_LhsDuration, _LhsDuration>
+{
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    bool operator()(const _LhsDuration& __lhs, const _LhsDuration& __rhs) const
+        {return __lhs.count() < __rhs.count();}
+};
+
+template <class _Rep1, class _Period1, class _Rep2, class _Period2>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+bool
+operator< (const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
+{
+    return __duration_lt<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >()(__lhs, __rhs);
+}
+
+// Duration >
+
+template <class _Rep1, class _Period1, class _Rep2, class _Period2>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+bool
+operator> (const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
+{
+    return __rhs < __lhs;
+}
+
+// Duration <=
+
+template <class _Rep1, class _Period1, class _Rep2, class _Period2>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+bool
+operator<=(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
+{
+    return !(__rhs < __lhs);
+}
+
+// Duration >=
+
+template <class _Rep1, class _Period1, class _Rep2, class _Period2>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+bool
+operator>=(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
+{
+    return !(__lhs < __rhs);
+}
+
+// Duration +
+
+template <class _Rep1, class _Period1, class _Rep2, class _Period2>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type
+operator+(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
+{
+    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Cd;
+    return _Cd(_Cd(__lhs).count() + _Cd(__rhs).count());
+}
+
+// Duration -
+
+template <class _Rep1, class _Period1, class _Rep2, class _Period2>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type
+operator-(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
+{
+    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Cd;
+    return _Cd(_Cd(__lhs).count() - _Cd(__rhs).count());
+}
+
+// Duration *
+
+template <class _Rep1, class _Period, class _Rep2>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+typename enable_if
+<
+    is_convertible<_Rep2, typename common_type<_Rep1, _Rep2>::type>::value,
+    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
+>::type
+operator*(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
+{
+    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
+    typedef duration<_Cr, _Period> _Cd;
+    return _Cd(_Cd(__d).count() * static_cast<_Cr>(__s));
+}
+
+template <class _Rep1, class _Period, class _Rep2>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+typename enable_if
+<
+    is_convertible<_Rep1, typename common_type<_Rep1, _Rep2>::type>::value,
+    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
+>::type
+operator*(const _Rep1& __s, const duration<_Rep2, _Period>& __d)
+{
+    return __d * __s;
+}
+
+// Duration /
+
+template <class _Duration, class _Rep, bool = __is_duration<_Rep>::value>
+struct __duration_divide_result
+{
+};
+
+template <class _Duration, class _Rep2,
+    bool = is_convertible<_Rep2,
+                          typename common_type<typename _Duration::rep, _Rep2>::type>::value>
+struct __duration_divide_imp
+{
+};
+
+template <class _Rep1, class _Period, class _Rep2>
+struct __duration_divide_imp<duration<_Rep1, _Period>, _Rep2, true>
+{
+    typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period> type;
+};
+
+template <class _Rep1, class _Period, class _Rep2>
+struct __duration_divide_result<duration<_Rep1, _Period>, _Rep2, false>
+    : __duration_divide_imp<duration<_Rep1, _Period>, _Rep2>
+{
+};
+
+template <class _Rep1, class _Period, class _Rep2>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+typename __duration_divide_result<duration<_Rep1, _Period>, _Rep2>::type
+operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
+{
+    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
+    typedef duration<_Cr, _Period> _Cd;
+    return _Cd(_Cd(__d).count() / static_cast<_Cr>(__s));
+}
+
+template <class _Rep1, class _Period1, class _Rep2, class _Period2>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+typename common_type<_Rep1, _Rep2>::type
+operator/(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
+{
+    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Ct;
+    return _Ct(__lhs).count() / _Ct(__rhs).count();
+}
+
+// Duration %
+
+template <class _Rep1, class _Period, class _Rep2>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+typename __duration_divide_result<duration<_Rep1, _Period>, _Rep2>::type
+operator%(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
+{
+    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
+    typedef duration<_Cr, _Period> _Cd;
+    return _Cd(_Cd(__d).count() % static_cast<_Cr>(__s));
+}
+
+template <class _Rep1, class _Period1, class _Rep2, class _Period2>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type
+operator%(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
+{
+    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
+    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Cd;
+    return _Cd(static_cast<_Cr>(_Cd(__lhs).count()) % static_cast<_Cr>(_Cd(__rhs).count()));
+}
+
+//////////////////////////////////////////////////////////
+///////////////////// time_point /////////////////////////
+//////////////////////////////////////////////////////////
+
+template <class _Clock, class _Duration = typename _Clock::duration>
+class _LIBCPP_TYPE_VIS_ONLY time_point
+{
+    static_assert(__is_duration<_Duration>::value,
+                  "Second template parameter of time_point must be a std::chrono::duration");
+public:
+    typedef _Clock                    clock;
+    typedef _Duration                 duration;
+    typedef typename duration::rep    rep;
+    typedef typename duration::period period;
+private:
+    duration __d_;
+
+public:
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 time_point() : __d_(duration::zero()) {}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 explicit time_point(const duration& __d) : __d_(__d) {}
+
+    // conversions
+    template <class _Duration2>
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    time_point(const time_point<clock, _Duration2>& t,
+        typename enable_if
+        <
+            is_convertible<_Duration2, duration>::value
+        >::type* = 0)
+            : __d_(t.time_since_epoch()) {}
+
+    // observer
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 duration time_since_epoch() const {return __d_;}
+
+    // arithmetic
+
+    _LIBCPP_INLINE_VISIBILITY time_point& operator+=(const duration& __d) {__d_ += __d; return *this;}
+    _LIBCPP_INLINE_VISIBILITY time_point& operator-=(const duration& __d) {__d_ -= __d; return *this;}
+
+    // special values
+
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR time_point min() {return time_point(duration::min());}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR time_point max() {return time_point(duration::max());}
+};
+
+} // chrono
+
+template <class _Clock, class _Duration1, class _Duration2>
+struct _LIBCPP_TYPE_VIS_ONLY common_type<chrono::time_point<_Clock, _Duration1>,
+                                         chrono::time_point<_Clock, _Duration2> >
+{
+    typedef chrono::time_point<_Clock, typename common_type<_Duration1, _Duration2>::type> type;
+};
+
+namespace chrono {
+
+template <class _ToDuration, class _Clock, class _Duration>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+time_point<_Clock, _ToDuration>
+time_point_cast(const time_point<_Clock, _Duration>& __t)
+{
+    return time_point<_Clock, _ToDuration>(_VSTD::chrono::duration_cast<_ToDuration>(__t.time_since_epoch()));
+}
+
+// time_point ==
+
+template <class _Clock, class _Duration1, class _Duration2>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+bool
+operator==(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
+{
+    return __lhs.time_since_epoch() == __rhs.time_since_epoch();
+}
+
+// time_point !=
+
+template <class _Clock, class _Duration1, class _Duration2>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+bool
+operator!=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
+{
+    return !(__lhs == __rhs);
+}
+
+// time_point <
+
+template <class _Clock, class _Duration1, class _Duration2>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+bool
+operator<(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
+{
+    return __lhs.time_since_epoch() < __rhs.time_since_epoch();
+}
+
+// time_point >
+
+template <class _Clock, class _Duration1, class _Duration2>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+bool
+operator>(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
+{
+    return __rhs < __lhs;
+}
+
+// time_point <=
+
+template <class _Clock, class _Duration1, class _Duration2>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+bool
+operator<=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
+{
+    return !(__rhs < __lhs);
+}
+
+// time_point >=
+
+template <class _Clock, class _Duration1, class _Duration2>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+bool
+operator>=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
+{
+    return !(__lhs < __rhs);
+}
+
+// time_point operator+(time_point x, duration y);
+
+template <class _Clock, class _Duration1, class _Rep2, class _Period2>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type>
+operator+(const time_point<_Clock, _Duration1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
+{
+    typedef time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type> _Tr;
+    return _Tr (__lhs.time_since_epoch() + __rhs);
+}
+
+// time_point operator+(duration x, time_point y);
+
+template <class _Rep1, class _Period1, class _Clock, class _Duration2>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+time_point<_Clock, typename common_type<duration<_Rep1, _Period1>, _Duration2>::type>
+operator+(const duration<_Rep1, _Period1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
+{
+    return __rhs + __lhs;
+}
+
+// time_point operator-(time_point x, duration y);
+
+template <class _Clock, class _Duration1, class _Rep2, class _Period2>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type>
+operator-(const time_point<_Clock, _Duration1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
+{
+    return __lhs + (-__rhs);
+}
+
+// duration operator-(time_point x, time_point y);
+
+template <class _Clock, class _Duration1, class _Duration2>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+typename common_type<_Duration1, _Duration2>::type
+operator-(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
+{
+    return __lhs.time_since_epoch() - __rhs.time_since_epoch();
+}
+
+//////////////////////////////////////////////////////////
+/////////////////////// clocks ///////////////////////////
+//////////////////////////////////////////////////////////
+
+class _LIBCPP_TYPE_VIS system_clock
+{
+public:
+    typedef microseconds                     duration;
+    typedef duration::rep                    rep;
+    typedef duration::period                 period;
+    typedef chrono::time_point<system_clock> time_point;
+    static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = false;
+
+    static time_point now() _NOEXCEPT;
+    static time_t     to_time_t  (const time_point& __t) _NOEXCEPT;
+    static time_point from_time_t(time_t __t) _NOEXCEPT;
+};
+
+#ifndef _LIBCPP_HAS_NO_MONOTONIC_CLOCK
+class _LIBCPP_TYPE_VIS steady_clock
+{
+public:
+    typedef nanoseconds                                   duration;
+    typedef duration::rep                                 rep;
+    typedef duration::period                              period;
+    typedef chrono::time_point<steady_clock, duration>    time_point;
+    static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = true;
+
+    static time_point now() _NOEXCEPT;
+};
+
+typedef steady_clock high_resolution_clock;
+#else
+typedef system_clock high_resolution_clock;
+#endif
+
+} // chrono
+
+#if _LIBCPP_STD_VER > 11
+// Suffixes for duration literals [time.duration.literals]
+inline namespace literals
+{ 
+  inline namespace chrono_literals
+  {
+
+    constexpr chrono::hours operator"" h(unsigned long long __h)
+    {
+        return chrono::hours(static_cast<chrono::hours::rep>(__h));
+    }
+
+    constexpr chrono::duration<long double, ratio<3600,1>> operator"" h(long double __h)
+    {
+        return chrono::duration<long double, ratio<3600,1>>(__h);
+    }
+
+
+    constexpr chrono::minutes operator"" min(unsigned long long __m)
+    {
+        return chrono::minutes(static_cast<chrono::minutes::rep>(__m));
+    }
+
+    constexpr chrono::duration<long double, ratio<60,1>> operator"" min(long double __m)
+    {
+        return chrono::duration<long double, ratio<60,1>> (__m);
+    }
+
+
+    constexpr chrono::seconds operator"" s(unsigned long long __s)
+    {
+        return chrono::seconds(static_cast<chrono::seconds::rep>(__s));
+    }
+
+    constexpr chrono::duration<long double> operator"" s(long double __s)
+    {
+        return chrono::duration<long double> (__s);
+    }
+
+
+    constexpr chrono::milliseconds operator"" ms(unsigned long long __ms)
+    {
+        return chrono::milliseconds(static_cast<chrono::milliseconds::rep>(__ms));
+    }
+
+    constexpr chrono::duration<long double, milli> operator"" ms(long double __ms)
+    {
+        return chrono::duration<long double, milli>(__ms);
+    }
+
+
+    constexpr chrono::microseconds operator"" us(unsigned long long __us)
+    {
+        return chrono::microseconds(static_cast<chrono::microseconds::rep>(__us));
+    }
+
+    constexpr chrono::duration<long double, micro> operator"" us(long double __us)
+    {
+        return chrono::duration<long double, micro> (__us);
+    }
+    
+
+    constexpr chrono::nanoseconds operator"" ns(unsigned long long __ns)
+    {
+        return chrono::nanoseconds(static_cast<chrono::nanoseconds::rep>(__ns));
+    }
+
+    constexpr chrono::duration<long double, nano> operator"" ns(long double __ns)
+    {
+        return chrono::duration<long double, nano> (__ns);
+    }
+
+}}
+
+namespace chrono { // hoist the literals into namespace std::chrono
+   using namespace literals::chrono_literals;
+}
+
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CHRONO

diff --git a/libcxx/include/cinttypes b/libcxx/include/cinttypes
new file mode 100644
index 0000000..cfd763c
--- /dev/null
+++ b/libcxx/include/cinttypes

@@ -0,0 +1,261 @@
+// -*- C++ -*-
+//===--------------------------- cinttypes --------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CINTTYPES
+#define _LIBCPP_CINTTYPES
+
+/*
+    cinttypes synopsis
+
+This entire header is C99 / C++0X
+
+#include <cstdint>  // <cinttypes> includes <cstdint>
+
+Macros:
+
+    PRId8
+    PRId16
+    PRId32
+    PRId64
+
+    PRIdLEAST8
+    PRIdLEAST16
+    PRIdLEAST32
+    PRIdLEAST64
+
+    PRIdFAST8
+    PRIdFAST16
+    PRIdFAST32
+    PRIdFAST64
+
+    PRIdMAX
+    PRIdPTR
+
+    PRIi8
+    PRIi16
+    PRIi32
+    PRIi64
+
+    PRIiLEAST8
+    PRIiLEAST16
+    PRIiLEAST32
+    PRIiLEAST64
+
+    PRIiFAST8
+    PRIiFAST16
+    PRIiFAST32
+    PRIiFAST64
+
+    PRIiMAX
+    PRIiPTR
+
+    PRIo8
+    PRIo16
+    PRIo32
+    PRIo64
+
+    PRIoLEAST8
+    PRIoLEAST16
+    PRIoLEAST32
+    PRIoLEAST64
+
+    PRIoFAST8
+    PRIoFAST16
+    PRIoFAST32
+    PRIoFAST64
+
+    PRIoMAX
+    PRIoPTR
+
+    PRIu8
+    PRIu16
+    PRIu32
+    PRIu64
+
+    PRIuLEAST8
+    PRIuLEAST16
+    PRIuLEAST32
+    PRIuLEAST64
+
+    PRIuFAST8
+    PRIuFAST16
+    PRIuFAST32
+    PRIuFAST64
+
+    PRIuMAX
+    PRIuPTR
+
+    PRIx8
+    PRIx16
+    PRIx32
+    PRIx64
+
+    PRIxLEAST8
+    PRIxLEAST16
+    PRIxLEAST32
+    PRIxLEAST64
+
+    PRIxFAST8
+    PRIxFAST16
+    PRIxFAST32
+    PRIxFAST64
+
+    PRIxMAX
+    PRIxPTR
+
+    PRIX8
+    PRIX16
+    PRIX32
+    PRIX64
+
+    PRIXLEAST8
+    PRIXLEAST16
+    PRIXLEAST32
+    PRIXLEAST64
+
+    PRIXFAST8
+    PRIXFAST16
+    PRIXFAST32
+    PRIXFAST64
+
+    PRIXMAX
+    PRIXPTR
+
+    SCNd8
+    SCNd16
+    SCNd32
+    SCNd64
+
+    SCNdLEAST8
+    SCNdLEAST16
+    SCNdLEAST32
+    SCNdLEAST64
+
+    SCNdFAST8
+    SCNdFAST16
+    SCNdFAST32
+    SCNdFAST64
+
+    SCNdMAX
+    SCNdPTR
+
+    SCNi8
+    SCNi16
+    SCNi32
+    SCNi64
+
+    SCNiLEAST8
+    SCNiLEAST16
+    SCNiLEAST32
+    SCNiLEAST64
+
+    SCNiFAST8
+    SCNiFAST16
+    SCNiFAST32
+    SCNiFAST64
+
+    SCNiMAX
+    SCNiPTR
+
+    SCNo8
+    SCNo16
+    SCNo32
+    SCNo64
+
+    SCNoLEAST8
+    SCNoLEAST16
+    SCNoLEAST32
+    SCNoLEAST64
+
+    SCNoFAST8
+    SCNoFAST16
+    SCNoFAST32
+    SCNoFAST64
+
+    SCNoMAX
+    SCNoPTR
+
+    SCNu8
+    SCNu16
+    SCNu32
+    SCNu64
+
+    SCNuLEAST8
+    SCNuLEAST16
+    SCNuLEAST32
+    SCNuLEAST64
+
+    SCNuFAST8
+    SCNuFAST16
+    SCNuFAST32
+    SCNuFAST64
+
+    SCNuMAX
+    SCNuPTR
+
+    SCNx8
+    SCNx16
+    SCNx32
+    SCNx64
+
+    SCNxLEAST8
+    SCNxLEAST16
+    SCNxLEAST32
+    SCNxLEAST64
+
+    SCNxFAST8
+    SCNxFAST16
+    SCNxFAST32
+    SCNxFAST64
+
+    SCNxMAX
+    SCNxPTR
+
+namespace std
+{
+
+Types:
+
+    imaxdiv_t
+
+intmax_t  imaxabs(intmax_t j);
+imaxdiv_t imaxdiv(intmax_t numer, intmax_t denom);
+intmax_t  strtoimax(const char* restrict nptr, char** restrict endptr, int base);
+uintmax_t strtoumax(const char* restrict nptr, char** restrict endptr, int base);
+intmax_t  wcstoimax(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);
+uintmax_t wcstoumax(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);
+
+}  // std
+*/
+
+#include <__config>
+#include <cstdint>
+#include <inttypes.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+using::imaxdiv_t;
+
+#undef imaxabs
+using::imaxabs;
+#undef imaxdiv
+using::imaxdiv;
+using::strtoimax;
+using::strtoumax;
+using::wcstoimax;
+using::wcstoumax;
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CINTTYPES

diff --git a/libcxx/include/ciso646 b/libcxx/include/ciso646
new file mode 100644
index 0000000..b2efc72
--- /dev/null
+++ b/libcxx/include/ciso646

@@ -0,0 +1,25 @@
+// -*- C++ -*-
+//===--------------------------- ciso646 ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CISO646
+#define _LIBCPP_CISO646
+
+/*
+    ciso646 synopsis
+
+*/
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#endif  // _LIBCPP_CISO646

diff --git a/libcxx/include/climits b/libcxx/include/climits
new file mode 100644
index 0000000..81ffecd
--- /dev/null
+++ b/libcxx/include/climits

@@ -0,0 +1,48 @@
+// -*- C++ -*-
+//===--------------------------- climits ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CLIMITS
+#define _LIBCPP_CLIMITS
+
+/*
+    climits synopsis
+
+Macros:
+
+    CHAR_BIT
+    SCHAR_MIN
+    SCHAR_MAX
+    UCHAR_MAX
+    CHAR_MIN
+    CHAR_MAX
+    MB_LEN_MAX
+    SHRT_MIN
+    SHRT_MAX
+    USHRT_MAX
+    INT_MIN
+    INT_MAX
+    UINT_MAX
+    LONG_MIN
+    LONG_MAX
+    ULONG_MAX
+    LLONG_MIN   // C99
+    LLONG_MAX   // C99
+    ULLONG_MAX  // C99
+
+*/
+
+#include <__config>
+#include <limits.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#endif  // _LIBCPP_CLIMITS

diff --git a/libcxx/include/clocale b/libcxx/include/clocale
new file mode 100644
index 0000000..05fa9c6
--- /dev/null
+++ b/libcxx/include/clocale

@@ -0,0 +1,55 @@
+// -*- C++ -*-
+//===--------------------------- clocale ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CLOCALE
+#define _LIBCPP_CLOCALE
+
+/*
+    clocale synopsis
+
+Macros:
+
+    LC_ALL
+    LC_COLLATE
+    LC_CTYPE
+    LC_MONETARY
+    LC_NUMERIC
+    LC_TIME
+    NULL
+
+namespace std
+{
+
+struct lconv;
+char* setlocale(int category, const char* locale);
+lconv* localeconv();
+
+}  // std
+
+*/
+
+#include <__config>
+#include <locale.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+using ::lconv;
+#ifndef _LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS
+using ::setlocale;
+#endif
+using ::localeconv;
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CLOCALE

diff --git a/libcxx/include/cmath b/libcxx/include/cmath
new file mode 100644
index 0000000..5f9aaed
--- /dev/null
+++ b/libcxx/include/cmath

@@ -0,0 +1,1697 @@
+// -*- C++ -*-
+//===---------------------------- cmath -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CMATH
+#define _LIBCPP_CMATH
+
+/*
+    cmath synopsis
+
+Macros:
+
+    HUGE_VAL
+    HUGE_VALF               // C99
+    HUGE_VALL               // C99
+    INFINITY                // C99
+    NAN                     // C99
+    FP_INFINITE             // C99
+    FP_NAN                  // C99
+    FP_NORMAL               // C99
+    FP_SUBNORMAL            // C99
+    FP_ZERO                 // C99
+    FP_FAST_FMA             // C99
+    FP_FAST_FMAF            // C99
+    FP_FAST_FMAL            // C99
+    FP_ILOGB0               // C99
+    FP_ILOGBNAN             // C99
+    MATH_ERRNO              // C99
+    MATH_ERREXCEPT          // C99
+    math_errhandling        // C99
+
+namespace std
+{
+
+Types:
+
+    float_t                 // C99
+    double_t                // C99
+
+// C90
+
+floating_point abs(floating_point x);
+
+floating_point acos (arithmetic x);
+float          acosf(float x);
+long double    acosl(long double x);
+
+floating_point asin (arithmetic x);
+float          asinf(float x);
+long double    asinl(long double x);
+
+floating_point atan (arithmetic x);
+float          atanf(float x);
+long double    atanl(long double x);
+
+floating_point atan2 (arithmetic y, arithmetic x);
+float          atan2f(float y, float x);
+long double    atan2l(long double y, long double x);
+
+floating_point ceil (arithmetic x);
+float          ceilf(float x);
+long double    ceill(long double x);
+
+floating_point cos (arithmetic x);
+float          cosf(float x);
+long double    cosl(long double x);
+
+floating_point cosh (arithmetic x);
+float          coshf(float x);
+long double    coshl(long double x);
+
+floating_point exp (arithmetic x);
+float          expf(float x);
+long double    expl(long double x);
+
+floating_point fabs (arithmetic x);
+float          fabsf(float x);
+long double    fabsl(long double x);
+
+floating_point floor (arithmetic x);
+float          floorf(float x);
+long double    floorl(long double x);
+
+floating_point fmod (arithmetic x, arithmetic y);
+float          fmodf(float x, float y);
+long double    fmodl(long double x, long double y);
+
+floating_point frexp (arithmetic value, int* exp);
+float          frexpf(float value, int* exp);
+long double    frexpl(long double value, int* exp);
+
+floating_point ldexp (arithmetic value, int exp);
+float          ldexpf(float value, int exp);
+long double    ldexpl(long double value, int exp);
+
+floating_point log (arithmetic x);
+float          logf(float x);
+long double    logl(long double x);
+
+floating_point log10 (arithmetic x);
+float          log10f(float x);
+long double    log10l(long double x);
+
+floating_point modf (floating_point value, floating_point* iptr);
+float          modff(float value, float* iptr);
+long double    modfl(long double value, long double* iptr);
+
+floating_point pow (arithmetic x, arithmetic y);
+float          powf(float x, float y);
+long double    powl(long double x, long double y);
+
+floating_point sin (arithmetic x);
+float          sinf(float x);
+long double    sinl(long double x);
+
+floating_point sinh (arithmetic x);
+float          sinhf(float x);
+long double    sinhl(long double x);
+
+floating_point sqrt (arithmetic x);
+float          sqrtf(float x);
+long double    sqrtl(long double x);
+
+floating_point tan (arithmetic x);
+float          tanf(float x);
+long double    tanl(long double x);
+
+floating_point tanh (arithmetic x);
+float          tanhf(float x);
+long double    tanhl(long double x);
+
+//  C99
+
+bool signbit(arithmetic x);
+
+int fpclassify(arithmetic x);
+
+bool isfinite(arithmetic x);
+bool isinf(arithmetic x);
+bool isnan(arithmetic x);
+bool isnormal(arithmetic x);
+
+bool isgreater(arithmetic x, arithmetic y);
+bool isgreaterequal(arithmetic x, arithmetic y);
+bool isless(arithmetic x, arithmetic y);
+bool islessequal(arithmetic x, arithmetic y);
+bool islessgreater(arithmetic x, arithmetic y);
+bool isunordered(arithmetic x, arithmetic y);
+
+floating_point acosh (arithmetic x);
+float          acoshf(float x);
+long double    acoshl(long double x);
+
+floating_point asinh (arithmetic x);
+float          asinhf(float x);
+long double    asinhl(long double x);
+
+floating_point atanh (arithmetic x);
+float          atanhf(float x);
+long double    atanhl(long double x);
+
+floating_point cbrt (arithmetic x);
+float          cbrtf(float x);
+long double    cbrtl(long double x);
+
+floating_point copysign (arithmetic x, arithmetic y);
+float          copysignf(float x, float y);
+long double    copysignl(long double x, long double y);
+
+floating_point erf (arithmetic x);
+float          erff(float x);
+long double    erfl(long double x);
+
+floating_point erfc (arithmetic x);
+float          erfcf(float x);
+long double    erfcl(long double x);
+
+floating_point exp2 (arithmetic x);
+float          exp2f(float x);
+long double    exp2l(long double x);
+
+floating_point expm1 (arithmetic x);
+float          expm1f(float x);
+long double    expm1l(long double x);
+
+floating_point fdim (arithmetic x, arithmetic y);
+float          fdimf(float x, float y);
+long double    fdiml(long double x, long double y);
+
+floating_point fma (arithmetic x, arithmetic y, arithmetic z);
+float          fmaf(float x, float y, float z);
+long double    fmal(long double x, long double y, long double z);
+
+floating_point fmax (arithmetic x, arithmetic y);
+float          fmaxf(float x, float y);
+long double    fmaxl(long double x, long double y);
+
+floating_point fmin (arithmetic x, arithmetic y);
+float          fminf(float x, float y);
+long double    fminl(long double x, long double y);
+
+floating_point hypot (arithmetic x, arithmetic y);
+float          hypotf(float x, float y);
+long double    hypotl(long double x, long double y);
+
+int ilogb (arithmetic x);
+int ilogbf(float x);
+int ilogbl(long double x);
+
+floating_point lgamma (arithmetic x);
+float          lgammaf(float x);
+long double    lgammal(long double x);
+
+long long llrint (arithmetic x);
+long long llrintf(float x);
+long long llrintl(long double x);
+
+long long llround (arithmetic x);
+long long llroundf(float x);
+long long llroundl(long double x);
+
+floating_point log1p (arithmetic x);
+float          log1pf(float x);
+long double    log1pl(long double x);
+
+floating_point log2 (arithmetic x);
+float          log2f(float x);
+long double    log2l(long double x);
+
+floating_point logb (arithmetic x);
+float          logbf(float x);
+long double    logbl(long double x);
+
+long lrint (arithmetic x);
+long lrintf(float x);
+long lrintl(long double x);
+
+long lround (arithmetic x);
+long lroundf(float x);
+long lroundl(long double x);
+
+double      nan (const char* str);
+float       nanf(const char* str);
+long double nanl(const char* str);
+
+floating_point nearbyint (arithmetic x);
+float          nearbyintf(float x);
+long double    nearbyintl(long double x);
+
+floating_point nextafter (arithmetic x, arithmetic y);
+float          nextafterf(float x, float y);
+long double    nextafterl(long double x, long double y);
+
+floating_point nexttoward (arithmetic x, long double y);
+float          nexttowardf(float x, long double y);
+long double    nexttowardl(long double x, long double y);
+
+floating_point remainder (arithmetic x, arithmetic y);
+float          remainderf(float x, float y);
+long double    remainderl(long double x, long double y);
+
+floating_point remquo (arithmetic x, arithmetic y, int* pquo);
+float          remquof(float x, float y, int* pquo);
+long double    remquol(long double x, long double y, int* pquo);
+
+floating_point rint (arithmetic x);
+float          rintf(float x);
+long double    rintl(long double x);
+
+floating_point round (arithmetic x);
+float          roundf(float x);
+long double    roundl(long double x);
+
+floating_point scalbln (arithmetic x, long ex);
+float          scalblnf(float x, long ex);
+long double    scalblnl(long double x, long ex);
+
+floating_point scalbn (arithmetic x, int ex);
+float          scalbnf(float x, int ex);
+long double    scalbnl(long double x, int ex);
+
+floating_point tgamma (arithmetic x);
+float          tgammaf(float x);
+long double    tgammal(long double x);
+
+floating_point trunc (arithmetic x);
+float          truncf(float x);
+long double    truncl(long double x);
+
+}  // std
+
+*/
+
+#include <__config>
+#include <math.h>
+#include <type_traits>
+
+#ifdef _LIBCPP_MSVCRT
+#include "support/win32/math_win32.h"
+#endif
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+// signbit
+
+#ifdef signbit
+
+template <class _A1>
+_LIBCPP_ALWAYS_INLINE
+bool
+__libcpp_signbit(_A1 __lcpp_x) _NOEXCEPT
+{
+    return signbit(__lcpp_x);
+}
+
+#undef signbit
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename std::enable_if<std::is_arithmetic<_A1>::value, bool>::type
+signbit(_A1 __lcpp_x) _NOEXCEPT
+{
+    return __libcpp_signbit((typename std::__promote<_A1>::type)__lcpp_x);
+}
+
+#endif  // signbit
+
+// fpclassify
+
+#ifdef fpclassify
+
+template <class _A1>
+_LIBCPP_ALWAYS_INLINE
+int
+__libcpp_fpclassify(_A1 __lcpp_x) _NOEXCEPT
+{
+    return fpclassify(__lcpp_x);
+}
+
+#undef fpclassify
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename std::enable_if<std::is_arithmetic<_A1>::value, int>::type
+fpclassify(_A1 __lcpp_x) _NOEXCEPT
+{
+    return __libcpp_fpclassify((typename std::__promote<_A1>::type)__lcpp_x);
+}
+
+#endif  // fpclassify
+
+// isfinite
+
+#ifdef isfinite
+
+template <class _A1>
+_LIBCPP_ALWAYS_INLINE
+bool
+__libcpp_isfinite(_A1 __lcpp_x) _NOEXCEPT
+{
+    return isfinite(__lcpp_x);
+}
+
+#undef isfinite
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename std::enable_if<std::is_arithmetic<_A1>::value, bool>::type
+isfinite(_A1 __lcpp_x) _NOEXCEPT
+{
+    return __libcpp_isfinite((typename std::__promote<_A1>::type)__lcpp_x);
+}
+
+#endif  // isfinite
+
+// isinf
+
+#ifdef isinf
+
+template <class _A1>
+_LIBCPP_ALWAYS_INLINE
+bool
+__libcpp_isinf(_A1 __lcpp_x) _NOEXCEPT
+{
+    return isinf(__lcpp_x);
+}
+
+#undef isinf
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename std::enable_if<std::is_arithmetic<_A1>::value, bool>::type
+isinf(_A1 __lcpp_x) _NOEXCEPT
+{
+    return __libcpp_isinf((typename std::__promote<_A1>::type)__lcpp_x);
+}
+
+#endif  // isinf
+
+// isnan
+
+#ifdef isnan
+
+template <class _A1>
+_LIBCPP_ALWAYS_INLINE
+bool
+__libcpp_isnan(_A1 __lcpp_x) _NOEXCEPT
+{
+    return isnan(__lcpp_x);
+}
+
+#undef isnan
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename std::enable_if<std::is_arithmetic<_A1>::value, bool>::type
+isnan(_A1 __lcpp_x) _NOEXCEPT
+{
+    return __libcpp_isnan((typename std::__promote<_A1>::type)__lcpp_x);
+}
+
+#endif  // isnan
+
+// isnormal
+
+#ifdef isnormal
+
+template <class _A1>
+_LIBCPP_ALWAYS_INLINE
+bool
+__libcpp_isnormal(_A1 __lcpp_x) _NOEXCEPT
+{
+    return isnormal(__lcpp_x);
+}
+
+#undef isnormal
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename std::enable_if<std::is_arithmetic<_A1>::value, bool>::type
+isnormal(_A1 __lcpp_x) _NOEXCEPT
+{
+    return __libcpp_isnormal((typename std::__promote<_A1>::type)__lcpp_x);
+}
+
+#endif  // isnormal
+
+// isgreater
+
+#ifdef isgreater
+
+template <class _A1, class _A2>
+_LIBCPP_ALWAYS_INLINE
+bool
+__libcpp_isgreater(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    return isgreater(__lcpp_x, __lcpp_y);
+}
+
+#undef isgreater
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename std::enable_if
+<
+    std::is_arithmetic<_A1>::value &&
+    std::is_arithmetic<_A2>::value,
+    bool
+>::type
+isgreater(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    typedef typename std::__promote<_A1, _A2>::type type;
+    return __libcpp_isgreater((type)__lcpp_x, (type)__lcpp_y);
+}
+
+#endif  // isgreater
+
+// isgreaterequal
+
+#ifdef isgreaterequal
+
+template <class _A1, class _A2>
+_LIBCPP_ALWAYS_INLINE
+bool
+__libcpp_isgreaterequal(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    return isgreaterequal(__lcpp_x, __lcpp_y);
+}
+
+#undef isgreaterequal
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename std::enable_if
+<
+    std::is_arithmetic<_A1>::value &&
+    std::is_arithmetic<_A2>::value,
+    bool
+>::type
+isgreaterequal(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    typedef typename std::__promote<_A1, _A2>::type type;
+    return __libcpp_isgreaterequal((type)__lcpp_x, (type)__lcpp_y);
+}
+
+#endif  // isgreaterequal
+
+// isless
+
+#ifdef isless
+
+template <class _A1, class _A2>
+_LIBCPP_ALWAYS_INLINE
+bool
+__libcpp_isless(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    return isless(__lcpp_x, __lcpp_y);
+}
+
+#undef isless
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename std::enable_if
+<
+    std::is_arithmetic<_A1>::value &&
+    std::is_arithmetic<_A2>::value,
+    bool
+>::type
+isless(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    typedef typename std::__promote<_A1, _A2>::type type;
+    return __libcpp_isless((type)__lcpp_x, (type)__lcpp_y);
+}
+
+#endif  // isless
+
+// islessequal
+
+#ifdef islessequal
+
+template <class _A1, class _A2>
+_LIBCPP_ALWAYS_INLINE
+bool
+__libcpp_islessequal(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    return islessequal(__lcpp_x, __lcpp_y);
+}
+
+#undef islessequal
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename std::enable_if
+<
+    std::is_arithmetic<_A1>::value &&
+    std::is_arithmetic<_A2>::value,
+    bool
+>::type
+islessequal(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    typedef typename std::__promote<_A1, _A2>::type type;
+    return __libcpp_islessequal((type)__lcpp_x, (type)__lcpp_y);
+}
+
+#endif  // islessequal
+
+// islessgreater
+
+#ifdef islessgreater
+
+template <class _A1, class _A2>
+_LIBCPP_ALWAYS_INLINE
+bool
+__libcpp_islessgreater(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    return islessgreater(__lcpp_x, __lcpp_y);
+}
+
+#undef islessgreater
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename std::enable_if
+<
+    std::is_arithmetic<_A1>::value &&
+    std::is_arithmetic<_A2>::value,
+    bool
+>::type
+islessgreater(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    typedef typename std::__promote<_A1, _A2>::type type;
+    return __libcpp_islessgreater((type)__lcpp_x, (type)__lcpp_y);
+}
+
+#endif  // islessgreater
+
+// isunordered
+
+#ifdef isunordered
+
+template <class _A1, class _A2>
+_LIBCPP_ALWAYS_INLINE
+bool
+__libcpp_isunordered(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    return isunordered(__lcpp_x, __lcpp_y);
+}
+
+#undef isunordered
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename std::enable_if
+<
+    std::is_arithmetic<_A1>::value &&
+    std::is_arithmetic<_A2>::value,
+    bool
+>::type
+isunordered(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    typedef typename std::__promote<_A1, _A2>::type type;
+    return __libcpp_isunordered((type)__lcpp_x, (type)__lcpp_y);
+}
+
+#endif  // isunordered
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+using ::signbit;
+using ::fpclassify;
+using ::isfinite;
+using ::isinf;
+using ::isnan;
+using ::isnormal;
+using ::isgreater;
+using ::isgreaterequal;
+using ::isless;
+using ::islessequal;
+using ::islessgreater;
+using ::isunordered;
+using ::isunordered;
+
+using ::float_t;
+using ::double_t;
+
+// abs
+
+#if defined(__sun__)
+using ::abs;
+#endif
+
+#if !defined(_AIX) && !defined(__sun__)
+inline _LIBCPP_INLINE_VISIBILITY
+float
+abs(float __lcpp_x) _NOEXCEPT {return fabsf(__lcpp_x);}
+
+inline _LIBCPP_INLINE_VISIBILITY
+double
+abs(double __lcpp_x) _NOEXCEPT {return fabs(__lcpp_x);}
+
+inline _LIBCPP_INLINE_VISIBILITY
+long double
+abs(long double __lcpp_x) _NOEXCEPT {return fabsl(__lcpp_x);}
+#endif // !defined(_AIX)
+
+#ifndef __sun__
+
+// acos
+
+using ::acos;
+using ::acosf;
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       acos(float __lcpp_x) _NOEXCEPT       {return acosf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double acos(long double __lcpp_x) _NOEXCEPT {return acosl(__lcpp_x);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+acos(_A1 __lcpp_x) _NOEXCEPT {return acos((double)__lcpp_x);}
+
+// asin
+
+using ::asin;
+using ::asinf;
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       asin(float __lcpp_x) _NOEXCEPT       {return asinf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double asin(long double __lcpp_x) _NOEXCEPT {return asinl(__lcpp_x);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+asin(_A1 __lcpp_x) _NOEXCEPT {return asin((double)__lcpp_x);}
+
+// atan
+
+using ::atan;
+using ::atanf;
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       atan(float __lcpp_x) _NOEXCEPT       {return atanf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double atan(long double __lcpp_x) _NOEXCEPT {return atanl(__lcpp_x);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+atan(_A1 __lcpp_x) _NOEXCEPT {return atan((double)__lcpp_x);}
+
+// atan2
+
+using ::atan2;
+using ::atan2f;
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       atan2(float __lcpp_y, float __lcpp_x) _NOEXCEPT             {return atan2f(__lcpp_y, __lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double atan2(long double __lcpp_y, long double __lcpp_x) _NOEXCEPT {return atan2l(__lcpp_y, __lcpp_x);}
+#endif
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __lazy_enable_if
+<
+    is_arithmetic<_A1>::value &&
+    is_arithmetic<_A2>::value,
+    __promote<_A1, _A2>
+>::type
+atan2(_A1 __lcpp_y, _A2 __lcpp_x) _NOEXCEPT
+{
+    typedef typename __promote<_A1, _A2>::type __result_type;
+    static_assert((!(is_same<_A1, __result_type>::value &&
+                      is_same<_A2, __result_type>::value)), "");
+    return atan2((__result_type)__lcpp_y, (__result_type)__lcpp_x);
+}
+
+// ceil
+
+using ::ceil;
+using ::ceilf;
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       ceil(float __lcpp_x) _NOEXCEPT       {return ceilf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double ceil(long double __lcpp_x) _NOEXCEPT {return ceill(__lcpp_x);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+ceil(_A1 __lcpp_x) _NOEXCEPT {return ceil((double)__lcpp_x);}
+
+// cos
+
+using ::cos;
+using ::cosf;
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       cos(float __lcpp_x) _NOEXCEPT       {return cosf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double cos(long double __lcpp_x) _NOEXCEPT {return cosl(__lcpp_x);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+cos(_A1 __lcpp_x) _NOEXCEPT {return cos((double)__lcpp_x);}
+
+// cosh
+
+using ::cosh;
+using ::coshf;
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       cosh(float __lcpp_x) _NOEXCEPT       {return coshf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double cosh(long double __lcpp_x) _NOEXCEPT {return coshl(__lcpp_x);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+cosh(_A1 __lcpp_x) _NOEXCEPT {return cosh((double)__lcpp_x);}
+
+#endif // __sun__
+// exp
+
+using ::exp;
+using ::expf;
+
+#ifndef __sun__
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       exp(float __lcpp_x) _NOEXCEPT       {return expf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double exp(long double __lcpp_x) _NOEXCEPT {return expl(__lcpp_x);}
+#endif
+
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+exp(_A1 __lcpp_x) _NOEXCEPT {return exp((double)__lcpp_x);}
+
+// fabs
+
+using ::fabs;
+using ::fabsf;
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       fabs(float __lcpp_x) _NOEXCEPT       {return fabsf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double fabs(long double __lcpp_x) _NOEXCEPT {return fabsl(__lcpp_x);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+fabs(_A1 __lcpp_x) _NOEXCEPT {return fabs((double)__lcpp_x);}
+
+// floor
+
+using ::floor;
+using ::floorf;
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       floor(float __lcpp_x) _NOEXCEPT       {return floorf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double floor(long double __lcpp_x) _NOEXCEPT {return floorl(__lcpp_x);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+floor(_A1 __lcpp_x) _NOEXCEPT {return floor((double)__lcpp_x);}
+
+// fmod
+
+#endif //__sun__
+using ::fmod;
+using ::fmodf;
+#ifndef __sun__
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       fmod(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return fmodf(__lcpp_x, __lcpp_y);}
+inline _LIBCPP_INLINE_VISIBILITY long double fmod(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return fmodl(__lcpp_x, __lcpp_y);}
+#endif
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __lazy_enable_if
+<
+    is_arithmetic<_A1>::value &&
+    is_arithmetic<_A2>::value,
+    __promote<_A1, _A2>
+>::type
+fmod(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    typedef typename __promote<_A1, _A2>::type __result_type;
+    static_assert((!(is_same<_A1, __result_type>::value &&
+                      is_same<_A2, __result_type>::value)), "");
+    return fmod((__result_type)__lcpp_x, (__result_type)__lcpp_y);
+}
+
+
+// frexp
+
+using ::frexp;
+using ::frexpf;
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       frexp(float __lcpp_x, int* __lcpp_e) _NOEXCEPT       {return frexpf(__lcpp_x, __lcpp_e);}
+inline _LIBCPP_INLINE_VISIBILITY long double frexp(long double __lcpp_x, int* __lcpp_e) _NOEXCEPT {return frexpl(__lcpp_x, __lcpp_e);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+frexp(_A1 __lcpp_x, int* __lcpp_e) _NOEXCEPT {return frexp((double)__lcpp_x, __lcpp_e);}
+
+// ldexp
+
+using ::ldexp;
+using ::ldexpf;
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       ldexp(float __lcpp_x, int __lcpp_e) _NOEXCEPT       {return ldexpf(__lcpp_x, __lcpp_e);}
+inline _LIBCPP_INLINE_VISIBILITY long double ldexp(long double __lcpp_x, int __lcpp_e) _NOEXCEPT {return ldexpl(__lcpp_x, __lcpp_e);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+ldexp(_A1 __lcpp_x, int __lcpp_e) _NOEXCEPT {return ldexp((double)__lcpp_x, __lcpp_e);}
+
+// log
+
+#endif // __sun__
+using ::log;
+using ::logf;
+#ifndef __sun__
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       log(float __lcpp_x) _NOEXCEPT       {return logf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double log(long double __lcpp_x) _NOEXCEPT {return logl(__lcpp_x);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+log(_A1 __lcpp_x) _NOEXCEPT {return log((double)__lcpp_x);}
+
+
+// log10
+
+using ::log10;
+using ::log10f;
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       log10(float __lcpp_x) _NOEXCEPT       {return log10f(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double log10(long double __lcpp_x) _NOEXCEPT {return log10l(__lcpp_x);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+log10(_A1 __lcpp_x) _NOEXCEPT {return log10((double)__lcpp_x);}
+
+// modf
+
+using ::modf;
+using ::modff;
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       modf(float __lcpp_x, float* __lcpp_y) _NOEXCEPT             {return modff(__lcpp_x, __lcpp_y);}
+inline _LIBCPP_INLINE_VISIBILITY long double modf(long double __lcpp_x, long double* __lcpp_y) _NOEXCEPT {return modfl(__lcpp_x, __lcpp_y);}
+#endif
+
+// pow
+
+#endif // __sun__ 
+using ::pow;
+using ::powf;
+
+#ifndef __sun__
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       pow(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return powf(__lcpp_x, __lcpp_y);}
+inline _LIBCPP_INLINE_VISIBILITY long double pow(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return powl(__lcpp_x, __lcpp_y);}
+#endif
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __lazy_enable_if
+<
+    is_arithmetic<_A1>::value &&
+    is_arithmetic<_A2>::value,
+    __promote<_A1, _A2>
+>::type
+pow(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    typedef typename __promote<_A1, _A2>::type __result_type;
+    static_assert((!(is_same<_A1, __result_type>::value &&
+                      is_same<_A2, __result_type>::value)), "");
+    return pow((__result_type)__lcpp_x, (__result_type)__lcpp_y);
+}
+
+// sin
+
+using ::sin;
+using ::sinf;
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       sin(float __lcpp_x) _NOEXCEPT       {return sinf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double sin(long double __lcpp_x) _NOEXCEPT {return sinl(__lcpp_x);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+sin(_A1 __lcpp_x) _NOEXCEPT {return sin((double)__lcpp_x);}
+
+// sinh
+
+using ::sinh;
+using ::sinhf;
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       sinh(float __lcpp_x) _NOEXCEPT       {return sinhf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double sinh(long double __lcpp_x) _NOEXCEPT {return sinhl(__lcpp_x);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+sinh(_A1 __lcpp_x) _NOEXCEPT {return sinh((double)__lcpp_x);}
+
+// sqrt
+
+#endif // __sun__
+using ::sqrt;
+using ::sqrtf;
+
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(__sun__) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       sqrt(float __lcpp_x) _NOEXCEPT       {return sqrtf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double sqrt(long double __lcpp_x) _NOEXCEPT {return sqrtl(__lcpp_x);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+sqrt(_A1 __lcpp_x) _NOEXCEPT {return sqrt((double)__lcpp_x);}
+
+// tan
+
+using ::tan;
+using ::tanf;
+#ifndef __sun__
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       tan(float __lcpp_x) _NOEXCEPT       {return tanf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double tan(long double __lcpp_x) _NOEXCEPT {return tanl(__lcpp_x);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+tan(_A1 __lcpp_x) _NOEXCEPT {return tan((double)__lcpp_x);}
+
+// tanh
+
+using ::tanh;
+using ::tanhf;
+
+#if !(defined(_LIBCPP_MSVCRT) || defined(_AIX))
+inline _LIBCPP_INLINE_VISIBILITY float       tanh(float __lcpp_x) _NOEXCEPT       {return tanhf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double tanh(long double __lcpp_x) _NOEXCEPT {return tanhl(__lcpp_x);}
+#endif
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+tanh(_A1 __lcpp_x) _NOEXCEPT {return tanh((double)__lcpp_x);}
+
+// acosh
+
+#ifndef _LIBCPP_MSVCRT
+using ::acosh;
+using ::acoshf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       acosh(float __lcpp_x) _NOEXCEPT       {return acoshf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double acosh(long double __lcpp_x) _NOEXCEPT {return acoshl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+acosh(_A1 __lcpp_x) _NOEXCEPT {return acosh((double)__lcpp_x);}
+#endif
+
+// asinh
+
+#ifndef _LIBCPP_MSVCRT
+using ::asinh;
+using ::asinhf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       asinh(float __lcpp_x) _NOEXCEPT       {return asinhf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double asinh(long double __lcpp_x) _NOEXCEPT {return asinhl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+asinh(_A1 __lcpp_x) _NOEXCEPT {return asinh((double)__lcpp_x);}
+#endif
+
+// atanh
+
+#ifndef _LIBCPP_MSVCRT
+using ::atanh;
+using ::atanhf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       atanh(float __lcpp_x) _NOEXCEPT       {return atanhf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double atanh(long double __lcpp_x) _NOEXCEPT {return atanhl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+atanh(_A1 __lcpp_x) _NOEXCEPT {return atanh((double)__lcpp_x);}
+#endif
+
+// cbrt
+
+#ifndef _LIBCPP_MSVCRT
+using ::cbrt;
+using ::cbrtf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       cbrt(float __lcpp_x) _NOEXCEPT       {return cbrtf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double cbrt(long double __lcpp_x) _NOEXCEPT {return cbrtl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+cbrt(_A1 __lcpp_x) _NOEXCEPT {return cbrt((double)__lcpp_x);}
+#endif
+
+// copysign
+
+using ::copysign;
+using ::copysignf;
+
+#if !defined(_VC_CRT_MAJOR_VERSION) || (_VC_CRT_MAJOR_VERSION < 12)
+inline _LIBCPP_INLINE_VISIBILITY float copysign(float __lcpp_x,
+                                                float __lcpp_y) _NOEXCEPT {
+  return copysignf(__lcpp_x, __lcpp_y);
+}
+inline _LIBCPP_INLINE_VISIBILITY long double
+copysign(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {
+  return copysignl(__lcpp_x, __lcpp_y);
+}
+#endif
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __lazy_enable_if
+<
+    is_arithmetic<_A1>::value &&
+    is_arithmetic<_A2>::value,
+    __promote<_A1, _A2>
+>::type
+copysign(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    typedef typename __promote<_A1, _A2>::type __result_type;
+    static_assert((!(is_same<_A1, __result_type>::value &&
+                      is_same<_A2, __result_type>::value)), "");
+    return copysign((__result_type)__lcpp_x, (__result_type)__lcpp_y);
+}
+
+#ifndef _LIBCPP_MSVCRT
+
+// erf
+
+using ::erf;
+using ::erff;
+
+inline _LIBCPP_INLINE_VISIBILITY float       erf(float __lcpp_x) _NOEXCEPT       {return erff(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double erf(long double __lcpp_x) _NOEXCEPT {return erfl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+erf(_A1 __lcpp_x) _NOEXCEPT {return erf((double)__lcpp_x);}
+
+// erfc
+
+using ::erfc;
+using ::erfcf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       erfc(float __lcpp_x) _NOEXCEPT       {return erfcf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double erfc(long double __lcpp_x) _NOEXCEPT {return erfcl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+erfc(_A1 __lcpp_x) _NOEXCEPT {return erfc((double)__lcpp_x);}
+
+// exp2
+
+using ::exp2;
+using ::exp2f;
+
+inline _LIBCPP_INLINE_VISIBILITY float       exp2(float __lcpp_x) _NOEXCEPT       {return exp2f(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double exp2(long double __lcpp_x) _NOEXCEPT {return exp2l(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+exp2(_A1 __lcpp_x) _NOEXCEPT {return exp2((double)__lcpp_x);}
+
+// expm1
+
+using ::expm1;
+using ::expm1f;
+
+inline _LIBCPP_INLINE_VISIBILITY float       expm1(float __lcpp_x) _NOEXCEPT       {return expm1f(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double expm1(long double __lcpp_x) _NOEXCEPT {return expm1l(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+expm1(_A1 __lcpp_x) _NOEXCEPT {return expm1((double)__lcpp_x);}
+
+// fdim
+
+using ::fdim;
+using ::fdimf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       fdim(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return fdimf(__lcpp_x, __lcpp_y);}
+inline _LIBCPP_INLINE_VISIBILITY long double fdim(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return fdiml(__lcpp_x, __lcpp_y);}
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __lazy_enable_if
+<
+    is_arithmetic<_A1>::value &&
+    is_arithmetic<_A2>::value,
+    __promote<_A1, _A2>
+>::type
+fdim(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    typedef typename __promote<_A1, _A2>::type __result_type;
+    static_assert((!(is_same<_A1, __result_type>::value &&
+                      is_same<_A2, __result_type>::value)), "");
+    return fdim((__result_type)__lcpp_x, (__result_type)__lcpp_y);
+}
+
+// fma
+
+using ::fmaf;
+using ::fma;
+
+inline _LIBCPP_INLINE_VISIBILITY float       fma(float __lcpp_x, float __lcpp_y, float __lcpp_z) _NOEXCEPT                   {return fmaf(__lcpp_x, __lcpp_y, __lcpp_z);}
+inline _LIBCPP_INLINE_VISIBILITY long double fma(long double __lcpp_x, long double __lcpp_y, long double __lcpp_z) _NOEXCEPT {return fmal(__lcpp_x, __lcpp_y, __lcpp_z);}
+
+template <class _A1, class _A2, class _A3>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __lazy_enable_if
+<
+    is_arithmetic<_A1>::value &&
+    is_arithmetic<_A2>::value &&
+    is_arithmetic<_A3>::value,
+    __promote<_A1, _A2, _A3>
+>::type
+fma(_A1 __lcpp_x, _A2 __lcpp_y, _A3 __lcpp_z) _NOEXCEPT
+{
+    typedef typename __promote<_A1, _A2, _A3>::type __result_type;
+    static_assert((!(is_same<_A1, __result_type>::value &&
+                      is_same<_A2, __result_type>::value &&
+                      is_same<_A3, __result_type>::value)), "");
+    return fma((__result_type)__lcpp_x, (__result_type)__lcpp_y, (__result_type)__lcpp_z);
+}
+
+// fmax
+
+using ::fmax;
+using ::fmaxf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       fmax(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return fmaxf(__lcpp_x, __lcpp_y);}
+inline _LIBCPP_INLINE_VISIBILITY long double fmax(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return fmaxl(__lcpp_x, __lcpp_y);}
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __lazy_enable_if
+<
+    is_arithmetic<_A1>::value &&
+    is_arithmetic<_A2>::value,
+    __promote<_A1, _A2>
+>::type
+fmax(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    typedef typename __promote<_A1, _A2>::type __result_type;
+    static_assert((!(is_same<_A1, __result_type>::value &&
+                      is_same<_A2, __result_type>::value)), "");
+    return fmax((__result_type)__lcpp_x, (__result_type)__lcpp_y);
+}
+
+// fmin
+
+using ::fmin;
+using ::fminf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       fmin(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return fminf(__lcpp_x, __lcpp_y);}
+inline _LIBCPP_INLINE_VISIBILITY long double fmin(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return fminl(__lcpp_x, __lcpp_y);}
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __lazy_enable_if
+<
+    is_arithmetic<_A1>::value &&
+    is_arithmetic<_A2>::value,
+    __promote<_A1, _A2>
+>::type
+fmin(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    typedef typename __promote<_A1, _A2>::type __result_type;
+    static_assert((!(is_same<_A1, __result_type>::value &&
+                      is_same<_A2, __result_type>::value)), "");
+    return fmin((__result_type)__lcpp_x, (__result_type)__lcpp_y);
+}
+
+// hypot
+
+using ::hypot;
+using ::hypotf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       hypot(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return hypotf(__lcpp_x, __lcpp_y);}
+inline _LIBCPP_INLINE_VISIBILITY long double hypot(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return hypotl(__lcpp_x, __lcpp_y);}
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __lazy_enable_if
+<
+    is_arithmetic<_A1>::value &&
+    is_arithmetic<_A2>::value,
+    __promote<_A1, _A2>
+>::type
+hypot(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    typedef typename __promote<_A1, _A2>::type __result_type;
+    static_assert((!(is_same<_A1, __result_type>::value &&
+                      is_same<_A2, __result_type>::value)), "");
+    return hypot((__result_type)__lcpp_x, (__result_type)__lcpp_y);
+}
+
+// ilogb
+
+using ::ilogb;
+using ::ilogbf;
+
+inline _LIBCPP_INLINE_VISIBILITY int ilogb(float __lcpp_x) _NOEXCEPT       {return ilogbf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY int ilogb(long double __lcpp_x) _NOEXCEPT {return ilogbl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, int>::type
+ilogb(_A1 __lcpp_x) _NOEXCEPT {return ilogb((double)__lcpp_x);}
+
+// lgamma
+
+using ::lgamma;
+using ::lgammaf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       lgamma(float __lcpp_x) _NOEXCEPT       {return lgammaf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double lgamma(long double __lcpp_x) _NOEXCEPT {return lgammal(__lcpp_x);}
+
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+lgamma(_A1 __lcpp_x) _NOEXCEPT {return lgamma((double)__lcpp_x);}
+
+
+// llrint
+
+using ::llrint;
+using ::llrintf;
+
+inline _LIBCPP_INLINE_VISIBILITY long long llrint(float __lcpp_x) _NOEXCEPT       {return llrintf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long long llrint(long double __lcpp_x) _NOEXCEPT {return llrintl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, long long>::type
+llrint(_A1 __lcpp_x) _NOEXCEPT {return llrint((double)__lcpp_x);}
+
+// llround
+
+using ::llround;
+using ::llroundf;
+
+inline _LIBCPP_INLINE_VISIBILITY long long llround(float __lcpp_x) _NOEXCEPT       {return llroundf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long long llround(long double __lcpp_x) _NOEXCEPT {return llroundl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, long long>::type
+llround(_A1 __lcpp_x) _NOEXCEPT {return llround((double)__lcpp_x);}
+
+// log1p
+
+using ::log1p;
+using ::log1pf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       log1p(float __lcpp_x) _NOEXCEPT       {return log1pf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double log1p(long double __lcpp_x) _NOEXCEPT {return log1pl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+log1p(_A1 __lcpp_x) _NOEXCEPT {return log1p((double)__lcpp_x);}
+
+// log2
+
+using ::log2;
+using ::log2f;
+
+inline _LIBCPP_INLINE_VISIBILITY float       log2(float __lcpp_x) _NOEXCEPT       {return log2f(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double log2(long double __lcpp_x) _NOEXCEPT {return log2l(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+log2(_A1 __lcpp_x) _NOEXCEPT {return log2((double)__lcpp_x);}
+
+// logb
+
+using ::logb;
+using ::logbf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       logb(float __lcpp_x) _NOEXCEPT       {return logbf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double logb(long double __lcpp_x) _NOEXCEPT {return logbl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+logb(_A1 __lcpp_x) _NOEXCEPT {return logb((double)__lcpp_x);}
+
+// lrint
+
+using ::lrint;
+using ::lrintf;
+
+inline _LIBCPP_INLINE_VISIBILITY long lrint(float __lcpp_x) _NOEXCEPT       {return lrintf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long lrint(long double __lcpp_x) _NOEXCEPT {return lrintl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, long>::type
+lrint(_A1 __lcpp_x) _NOEXCEPT {return lrint((double)__lcpp_x);}
+
+// lround
+
+using ::lround;
+using ::lroundf;
+
+inline _LIBCPP_INLINE_VISIBILITY long lround(float __lcpp_x) _NOEXCEPT       {return lroundf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long lround(long double __lcpp_x) _NOEXCEPT {return lroundl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, long>::type
+lround(_A1 __lcpp_x) _NOEXCEPT {return lround((double)__lcpp_x);}
+
+#endif // _LIBCPP_MSVCRT
+#endif // __sun__
+
+// nan
+
+#ifndef _LIBCPP_MSVCRT
+using ::nan;
+using ::nanf;
+#endif // _LIBCPP_MSVCRT
+
+#ifndef __sun__
+#ifndef _LIBCPP_MSVCRT
+
+// nearbyint
+
+using ::nearbyint;
+using ::nearbyintf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       nearbyint(float __lcpp_x) _NOEXCEPT       {return nearbyintf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double nearbyint(long double __lcpp_x) _NOEXCEPT {return nearbyintl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+nearbyint(_A1 __lcpp_x) _NOEXCEPT {return nearbyint((double)__lcpp_x);}
+
+// nextafter
+
+using ::nextafter;
+using ::nextafterf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       nextafter(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return nextafterf(__lcpp_x, __lcpp_y);}
+inline _LIBCPP_INLINE_VISIBILITY long double nextafter(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return nextafterl(__lcpp_x, __lcpp_y);}
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __lazy_enable_if
+<
+    is_arithmetic<_A1>::value &&
+    is_arithmetic<_A2>::value,
+    __promote<_A1, _A2>
+>::type
+nextafter(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    typedef typename __promote<_A1, _A2>::type __result_type;
+    static_assert((!(is_same<_A1, __result_type>::value &&
+                      is_same<_A2, __result_type>::value)), "");
+    return nextafter((__result_type)__lcpp_x, (__result_type)__lcpp_y);
+}
+
+// nexttoward
+
+using ::nexttoward;
+using ::nexttowardf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       nexttoward(float __lcpp_x, long double __lcpp_y) _NOEXCEPT       {return nexttowardf(__lcpp_x, __lcpp_y);}
+inline _LIBCPP_INLINE_VISIBILITY long double nexttoward(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return nexttowardl(__lcpp_x, __lcpp_y);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+nexttoward(_A1 __lcpp_x, long double __lcpp_y) _NOEXCEPT {return nexttoward((double)__lcpp_x, __lcpp_y);}
+
+// remainder
+
+using ::remainder;
+using ::remainderf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       remainder(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return remainderf(__lcpp_x, __lcpp_y);}
+inline _LIBCPP_INLINE_VISIBILITY long double remainder(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return remainderl(__lcpp_x, __lcpp_y);}
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __lazy_enable_if
+<
+    is_arithmetic<_A1>::value &&
+    is_arithmetic<_A2>::value,
+    __promote<_A1, _A2>
+>::type
+remainder(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
+{
+    typedef typename __promote<_A1, _A2>::type __result_type;
+    static_assert((!(is_same<_A1, __result_type>::value &&
+                      is_same<_A2, __result_type>::value)), "");
+    return remainder((__result_type)__lcpp_x, (__result_type)__lcpp_y);
+}
+
+// remquo
+
+using ::remquo;
+using ::remquof;
+
+inline _LIBCPP_INLINE_VISIBILITY float       remquo(float __lcpp_x, float __lcpp_y, int* __lcpp_z) _NOEXCEPT             {return remquof(__lcpp_x, __lcpp_y, __lcpp_z);}
+inline _LIBCPP_INLINE_VISIBILITY long double remquo(long double __lcpp_x, long double __lcpp_y, int* __lcpp_z) _NOEXCEPT {return remquol(__lcpp_x, __lcpp_y, __lcpp_z);}
+
+template <class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __lazy_enable_if
+<
+    is_arithmetic<_A1>::value &&
+    is_arithmetic<_A2>::value,
+    __promote<_A1, _A2>
+>::type
+remquo(_A1 __lcpp_x, _A2 __lcpp_y, int* __lcpp_z) _NOEXCEPT
+{
+    typedef typename __promote<_A1, _A2>::type __result_type;
+    static_assert((!(is_same<_A1, __result_type>::value &&
+                      is_same<_A2, __result_type>::value)), "");
+    return remquo((__result_type)__lcpp_x, (__result_type)__lcpp_y, __lcpp_z);
+}
+
+// rint
+
+using ::rint;
+using ::rintf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       rint(float __lcpp_x) _NOEXCEPT       {return rintf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double rint(long double __lcpp_x) _NOEXCEPT {return rintl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+rint(_A1 __lcpp_x) _NOEXCEPT {return rint((double)__lcpp_x);}
+
+// round
+
+using ::round;
+using ::roundf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       round(float __lcpp_x) _NOEXCEPT       {return roundf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double round(long double __lcpp_x) _NOEXCEPT {return roundl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+round(_A1 __lcpp_x) _NOEXCEPT {return round((double)__lcpp_x);}
+
+// scalbln
+
+using ::scalbln;
+using ::scalblnf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       scalbln(float __lcpp_x, long __lcpp_y) _NOEXCEPT       {return scalblnf(__lcpp_x, __lcpp_y);}
+inline _LIBCPP_INLINE_VISIBILITY long double scalbln(long double __lcpp_x, long __lcpp_y) _NOEXCEPT {return scalblnl(__lcpp_x, __lcpp_y);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+scalbln(_A1 __lcpp_x, long __lcpp_y) _NOEXCEPT {return scalbln((double)__lcpp_x, __lcpp_y);}
+
+// scalbn
+
+using ::scalbn;
+using ::scalbnf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       scalbn(float __lcpp_x, int __lcpp_y) _NOEXCEPT       {return scalbnf(__lcpp_x, __lcpp_y);}
+inline _LIBCPP_INLINE_VISIBILITY long double scalbn(long double __lcpp_x, int __lcpp_y) _NOEXCEPT {return scalbnl(__lcpp_x, __lcpp_y);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+scalbn(_A1 __lcpp_x, int __lcpp_y) _NOEXCEPT {return scalbn((double)__lcpp_x, __lcpp_y);}
+
+// tgamma
+
+using ::tgamma;
+using ::tgammaf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       tgamma(float __lcpp_x) _NOEXCEPT       {return tgammaf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double tgamma(long double __lcpp_x) _NOEXCEPT {return tgammal(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+tgamma(_A1 __lcpp_x) _NOEXCEPT {return tgamma((double)__lcpp_x);}
+
+// trunc
+
+using ::trunc;
+using ::truncf;
+
+inline _LIBCPP_INLINE_VISIBILITY float       trunc(float __lcpp_x) _NOEXCEPT       {return truncf(__lcpp_x);}
+inline _LIBCPP_INLINE_VISIBILITY long double trunc(long double __lcpp_x) _NOEXCEPT {return truncl(__lcpp_x);}
+
+template <class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if<is_integral<_A1>::value, double>::type
+trunc(_A1 __lcpp_x) _NOEXCEPT {return trunc((double)__lcpp_x);}
+
+#endif // !_LIBCPP_MSVCRT
+
+using ::acosl;
+using ::asinl;
+using ::atanl;
+using ::atan2l;
+using ::ceill;
+using ::cosl;
+using ::coshl;
+using ::expl;
+using ::fabsl;
+using ::floorl;
+using ::fmodl;
+using ::frexpl;
+using ::ldexpl;
+using ::logl;
+using ::log10l;
+using ::modfl;
+using ::powl;
+using ::sinl;
+using ::sinhl;
+using ::sqrtl;
+using ::tanl;
+#ifndef _LIBCPP_MSVCRT
+using ::tanhl;
+using ::acoshl;
+using ::asinhl;
+using ::atanhl;
+using ::cbrtl;
+#endif  // !_LIBCPP_MSVCRT
+using ::copysignl;
+#ifndef _LIBCPP_MSVCRT
+using ::erfl;
+using ::erfcl;
+using ::exp2l;
+using ::expm1l;
+using ::fdiml;
+using ::fmal;
+using ::fmaxl;
+using ::fminl;
+using ::hypotl;
+using ::ilogbl;
+using ::lgammal;
+using ::llrintl;
+using ::llroundl;
+using ::log1pl;
+using ::log2l;
+using ::logbl;
+using ::lrintl;
+using ::lroundl;
+using ::nanl;
+using ::nearbyintl;
+using ::nextafterl;
+using ::nexttowardl;
+using ::remainderl;
+using ::remquol;
+using ::rintl;
+using ::roundl;
+using ::scalblnl;
+using ::scalbnl;
+using ::tgammal;
+using ::truncl;
+#endif // !_LIBCPP_MSVCRT
+
+#else 
+using ::lgamma;
+using ::lgammaf;
+#endif // __sun__
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CMATH

diff --git a/libcxx/include/codecvt b/libcxx/include/codecvt
new file mode 100644
index 0000000..6eff107
--- /dev/null
+++ b/libcxx/include/codecvt

@@ -0,0 +1,550 @@
+// -*- C++ -*-
+//===-------------------------- codecvt -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CODECVT
+#define _LIBCPP_CODECVT
+
+/*
+    codecvt synopsis
+
+namespace std
+{
+
+enum codecvt_mode
+{
+    consume_header = 4,
+    generate_header = 2,
+    little_endian = 1
+};
+
+template <class Elem, unsigned long Maxcode = 0x10ffff,
+          codecvt_mode Mode = (codecvt_mode)0>
+class codecvt_utf8
+    : public codecvt<Elem, char, mbstate_t>
+{
+    explicit codecvt_utf8(size_t refs = 0);
+    ~codecvt_utf8();
+};
+
+template <class Elem, unsigned long Maxcode = 0x10ffff,
+          codecvt_mode Mode = (codecvt_mode)0>
+class codecvt_utf16
+    : public codecvt<Elem, char, mbstate_t>
+{
+    explicit codecvt_utf16(size_t refs = 0);
+    ~codecvt_utf16();
+};
+
+template <class Elem, unsigned long Maxcode = 0x10ffff,
+          codecvt_mode Mode = (codecvt_mode)0>
+class codecvt_utf8_utf16
+    : public codecvt<Elem, char, mbstate_t>
+{
+    explicit codecvt_utf8_utf16(size_t refs = 0);
+    ~codecvt_utf8_utf16();
+};
+
+}  // std
+
+*/
+
+#include <__config>
+#include <__locale>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+enum codecvt_mode
+{
+    consume_header = 4,
+    generate_header = 2,
+    little_endian = 1
+};
+
+// codecvt_utf8
+
+template <class _Elem> class __codecvt_utf8;
+
+template <>
+class _LIBCPP_TYPE_VIS __codecvt_utf8<wchar_t>
+    : public codecvt<wchar_t, char, mbstate_t>
+{
+    unsigned long _Maxcode_;
+    codecvt_mode _Mode_;
+public:
+    typedef wchar_t   intern_type;
+    typedef char      extern_type;
+    typedef mbstate_t state_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit __codecvt_utf8(size_t __refs, unsigned long _Maxcode,
+                            codecvt_mode _Mode)
+        : codecvt<wchar_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
+          _Mode_(_Mode) {}
+protected:
+    virtual result
+        do_out(state_type& __st,
+               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual result
+        do_in(state_type& __st,
+              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
+    virtual result
+        do_unshift(state_type& __st,
+                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual int do_encoding() const throw();
+    virtual bool do_always_noconv() const throw();
+    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
+                          size_t __mx) const;
+    virtual int do_max_length() const throw();
+};
+
+template <>
+class _LIBCPP_TYPE_VIS __codecvt_utf8<char16_t>
+    : public codecvt<char16_t, char, mbstate_t>
+{
+    unsigned long _Maxcode_;
+    codecvt_mode _Mode_;
+public:
+    typedef char16_t  intern_type;
+    typedef char      extern_type;
+    typedef mbstate_t state_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit __codecvt_utf8(size_t __refs, unsigned long _Maxcode,
+                            codecvt_mode _Mode)
+        : codecvt<char16_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
+          _Mode_(_Mode) {}
+protected:
+    virtual result
+        do_out(state_type& __st,
+               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual result
+        do_in(state_type& __st,
+              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
+    virtual result
+        do_unshift(state_type& __st,
+                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual int do_encoding() const throw();
+    virtual bool do_always_noconv() const throw();
+    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
+                          size_t __mx) const;
+    virtual int do_max_length() const throw();
+};
+
+template <>
+class _LIBCPP_TYPE_VIS __codecvt_utf8<char32_t>
+    : public codecvt<char32_t, char, mbstate_t>
+{
+    unsigned long _Maxcode_;
+    codecvt_mode _Mode_;
+public:
+    typedef char32_t  intern_type;
+    typedef char      extern_type;
+    typedef mbstate_t state_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit __codecvt_utf8(size_t __refs, unsigned long _Maxcode,
+                            codecvt_mode _Mode)
+        : codecvt<char32_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
+          _Mode_(_Mode) {}
+protected:
+    virtual result
+        do_out(state_type& __st,
+               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual result
+        do_in(state_type& __st,
+              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
+    virtual result
+        do_unshift(state_type& __st,
+                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual int do_encoding() const throw();
+    virtual bool do_always_noconv() const throw();
+    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
+                          size_t __mx) const;
+    virtual int do_max_length() const throw();
+};
+
+template <class _Elem, unsigned long _Maxcode = 0x10ffff,
+          codecvt_mode _Mode = (codecvt_mode)0>
+class _LIBCPP_TYPE_VIS_ONLY codecvt_utf8
+    : public __codecvt_utf8<_Elem>
+{
+public:
+    _LIBCPP_ALWAYS_INLINE
+    explicit codecvt_utf8(size_t __refs = 0)
+        : __codecvt_utf8<_Elem>(__refs, _Maxcode, _Mode) {}
+
+    _LIBCPP_ALWAYS_INLINE
+    ~codecvt_utf8() {}
+};
+
+// codecvt_utf16
+
+template <class _Elem, bool _LittleEndian> class __codecvt_utf16;
+
+template <>
+class _LIBCPP_TYPE_VIS __codecvt_utf16<wchar_t, false>
+    : public codecvt<wchar_t, char, mbstate_t>
+{
+    unsigned long _Maxcode_;
+    codecvt_mode _Mode_;
+public:
+    typedef wchar_t   intern_type;
+    typedef char      extern_type;
+    typedef mbstate_t state_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit __codecvt_utf16(size_t __refs, unsigned long _Maxcode,
+                            codecvt_mode _Mode)
+        : codecvt<wchar_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
+          _Mode_(_Mode) {}
+protected:
+    virtual result
+        do_out(state_type& __st,
+               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual result
+        do_in(state_type& __st,
+              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
+    virtual result
+        do_unshift(state_type& __st,
+                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual int do_encoding() const throw();
+    virtual bool do_always_noconv() const throw();
+    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
+                          size_t __mx) const;
+    virtual int do_max_length() const throw();
+};
+
+template <>
+class _LIBCPP_TYPE_VIS __codecvt_utf16<wchar_t, true>
+    : public codecvt<wchar_t, char, mbstate_t>
+{
+    unsigned long _Maxcode_;
+    codecvt_mode _Mode_;
+public:
+    typedef wchar_t   intern_type;
+    typedef char      extern_type;
+    typedef mbstate_t state_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit __codecvt_utf16(size_t __refs, unsigned long _Maxcode,
+                            codecvt_mode _Mode)
+        : codecvt<wchar_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
+          _Mode_(_Mode) {}
+protected:
+    virtual result
+        do_out(state_type& __st,
+               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual result
+        do_in(state_type& __st,
+              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
+    virtual result
+        do_unshift(state_type& __st,
+                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual int do_encoding() const throw();
+    virtual bool do_always_noconv() const throw();
+    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
+                          size_t __mx) const;
+    virtual int do_max_length() const throw();
+};
+
+template <>
+class _LIBCPP_TYPE_VIS __codecvt_utf16<char16_t, false>
+    : public codecvt<char16_t, char, mbstate_t>
+{
+    unsigned long _Maxcode_;
+    codecvt_mode _Mode_;
+public:
+    typedef char16_t  intern_type;
+    typedef char      extern_type;
+    typedef mbstate_t state_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit __codecvt_utf16(size_t __refs, unsigned long _Maxcode,
+                            codecvt_mode _Mode)
+        : codecvt<char16_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
+          _Mode_(_Mode) {}
+protected:
+    virtual result
+        do_out(state_type& __st,
+               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual result
+        do_in(state_type& __st,
+              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
+    virtual result
+        do_unshift(state_type& __st,
+                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual int do_encoding() const throw();
+    virtual bool do_always_noconv() const throw();
+    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
+                          size_t __mx) const;
+    virtual int do_max_length() const throw();
+};
+
+template <>
+class _LIBCPP_TYPE_VIS __codecvt_utf16<char16_t, true>
+    : public codecvt<char16_t, char, mbstate_t>
+{
+    unsigned long _Maxcode_;
+    codecvt_mode _Mode_;
+public:
+    typedef char16_t  intern_type;
+    typedef char      extern_type;
+    typedef mbstate_t state_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit __codecvt_utf16(size_t __refs, unsigned long _Maxcode,
+                            codecvt_mode _Mode)
+        : codecvt<char16_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
+          _Mode_(_Mode) {}
+protected:
+    virtual result
+        do_out(state_type& __st,
+               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual result
+        do_in(state_type& __st,
+              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
+    virtual result
+        do_unshift(state_type& __st,
+                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual int do_encoding() const throw();
+    virtual bool do_always_noconv() const throw();
+    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
+                          size_t __mx) const;
+    virtual int do_max_length() const throw();
+};
+
+template <>
+class _LIBCPP_TYPE_VIS __codecvt_utf16<char32_t, false>
+    : public codecvt<char32_t, char, mbstate_t>
+{
+    unsigned long _Maxcode_;
+    codecvt_mode _Mode_;
+public:
+    typedef char32_t  intern_type;
+    typedef char      extern_type;
+    typedef mbstate_t state_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit __codecvt_utf16(size_t __refs, unsigned long _Maxcode,
+                            codecvt_mode _Mode)
+        : codecvt<char32_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
+          _Mode_(_Mode) {}
+protected:
+    virtual result
+        do_out(state_type& __st,
+               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual result
+        do_in(state_type& __st,
+              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
+    virtual result
+        do_unshift(state_type& __st,
+                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual int do_encoding() const throw();
+    virtual bool do_always_noconv() const throw();
+    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
+                          size_t __mx) const;
+    virtual int do_max_length() const throw();
+};
+
+template <>
+class _LIBCPP_TYPE_VIS __codecvt_utf16<char32_t, true>
+    : public codecvt<char32_t, char, mbstate_t>
+{
+    unsigned long _Maxcode_;
+    codecvt_mode _Mode_;
+public:
+    typedef char32_t  intern_type;
+    typedef char      extern_type;
+    typedef mbstate_t state_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit __codecvt_utf16(size_t __refs, unsigned long _Maxcode,
+                            codecvt_mode _Mode)
+        : codecvt<char32_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
+          _Mode_(_Mode) {}
+protected:
+    virtual result
+        do_out(state_type& __st,
+               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual result
+        do_in(state_type& __st,
+              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
+    virtual result
+        do_unshift(state_type& __st,
+                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual int do_encoding() const throw();
+    virtual bool do_always_noconv() const throw();
+    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
+                          size_t __mx) const;
+    virtual int do_max_length() const throw();
+};
+
+template <class _Elem, unsigned long _Maxcode = 0x10ffff,
+          codecvt_mode _Mode = (codecvt_mode)0>
+class _LIBCPP_TYPE_VIS_ONLY codecvt_utf16
+    : public __codecvt_utf16<_Elem, _Mode & little_endian>
+{
+public:
+    _LIBCPP_ALWAYS_INLINE
+    explicit codecvt_utf16(size_t __refs = 0)
+        : __codecvt_utf16<_Elem, _Mode & little_endian>(__refs, _Maxcode, _Mode) {}
+
+    _LIBCPP_ALWAYS_INLINE
+    ~codecvt_utf16() {}
+};
+
+// codecvt_utf8_utf16
+
+template <class _Elem> class __codecvt_utf8_utf16;
+
+template <>
+class _LIBCPP_TYPE_VIS __codecvt_utf8_utf16<wchar_t>
+    : public codecvt<wchar_t, char, mbstate_t>
+{
+    unsigned long _Maxcode_;
+    codecvt_mode _Mode_;
+public:
+    typedef wchar_t   intern_type;
+    typedef char      extern_type;
+    typedef mbstate_t state_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit __codecvt_utf8_utf16(size_t __refs, unsigned long _Maxcode,
+                            codecvt_mode _Mode)
+        : codecvt<wchar_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
+          _Mode_(_Mode) {}
+protected:
+    virtual result
+        do_out(state_type& __st,
+               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual result
+        do_in(state_type& __st,
+              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
+    virtual result
+        do_unshift(state_type& __st,
+                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual int do_encoding() const throw();
+    virtual bool do_always_noconv() const throw();
+    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
+                          size_t __mx) const;
+    virtual int do_max_length() const throw();
+};
+
+template <>
+class _LIBCPP_TYPE_VIS __codecvt_utf8_utf16<char32_t>
+    : public codecvt<char32_t, char, mbstate_t>
+{
+    unsigned long _Maxcode_;
+    codecvt_mode _Mode_;
+public:
+    typedef char32_t  intern_type;
+    typedef char      extern_type;
+    typedef mbstate_t state_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit __codecvt_utf8_utf16(size_t __refs, unsigned long _Maxcode,
+                            codecvt_mode _Mode)
+        : codecvt<char32_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
+          _Mode_(_Mode) {}
+protected:
+    virtual result
+        do_out(state_type& __st,
+               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual result
+        do_in(state_type& __st,
+              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
+    virtual result
+        do_unshift(state_type& __st,
+                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual int do_encoding() const throw();
+    virtual bool do_always_noconv() const throw();
+    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
+                          size_t __mx) const;
+    virtual int do_max_length() const throw();
+};
+
+template <>
+class _LIBCPP_TYPE_VIS __codecvt_utf8_utf16<char16_t>
+    : public codecvt<char16_t, char, mbstate_t>
+{
+    unsigned long _Maxcode_;
+    codecvt_mode _Mode_;
+public:
+    typedef char16_t  intern_type;
+    typedef char      extern_type;
+    typedef mbstate_t state_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit __codecvt_utf8_utf16(size_t __refs, unsigned long _Maxcode,
+                            codecvt_mode _Mode)
+        : codecvt<char16_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
+          _Mode_(_Mode) {}
+protected:
+    virtual result
+        do_out(state_type& __st,
+               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
+               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual result
+        do_in(state_type& __st,
+              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
+              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
+    virtual result
+        do_unshift(state_type& __st,
+                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+    virtual int do_encoding() const throw();
+    virtual bool do_always_noconv() const throw();
+    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
+                          size_t __mx) const;
+    virtual int do_max_length() const throw();
+};
+
+template <class _Elem, unsigned long _Maxcode = 0x10ffff,
+          codecvt_mode _Mode = (codecvt_mode)0>
+class _LIBCPP_TYPE_VIS_ONLY codecvt_utf8_utf16
+    : public __codecvt_utf8_utf16<_Elem>
+{
+public:
+    _LIBCPP_ALWAYS_INLINE
+    explicit codecvt_utf8_utf16(size_t __refs = 0)
+        : __codecvt_utf8_utf16<_Elem>(__refs, _Maxcode, _Mode) {}
+
+    _LIBCPP_ALWAYS_INLINE
+    ~codecvt_utf8_utf16() {}
+};
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CODECVT

diff --git a/libcxx/include/complex b/libcxx/include/complex
new file mode 100644
index 0000000..2943da1
--- /dev/null
+++ b/libcxx/include/complex

@@ -0,0 +1,1567 @@
+// -*- C++ -*-
+//===--------------------------- complex ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_COMPLEX
+#define _LIBCPP_COMPLEX
+
+/*
+    complex synopsis
+
+namespace std
+{
+
+template<class T>
+class complex
+{
+public:
+    typedef T value_type;
+
+    complex(const T& re = T(), const T& im = T()); // constexpr in C++14
+    complex(const complex&);  // constexpr in C++14
+    template<class X> complex(const complex<X>&);  // constexpr in C++14
+
+    T real() const; // constexpr in C++14
+    T imag() const; // constexpr in C++14
+
+    void real(T);
+    void imag(T);
+
+    complex<T>& operator= (const T&);
+    complex<T>& operator+=(const T&);
+    complex<T>& operator-=(const T&);
+    complex<T>& operator*=(const T&);
+    complex<T>& operator/=(const T&);
+
+    complex& operator=(const complex&);
+    template<class X> complex<T>& operator= (const complex<X>&);
+    template<class X> complex<T>& operator+=(const complex<X>&);
+    template<class X> complex<T>& operator-=(const complex<X>&);
+    template<class X> complex<T>& operator*=(const complex<X>&);
+    template<class X> complex<T>& operator/=(const complex<X>&);
+};
+
+template<>
+class complex<float>
+{
+public:
+    typedef float value_type;
+
+    constexpr complex(float re = 0.0f, float im = 0.0f);
+    explicit constexpr complex(const complex<double>&);
+    explicit constexpr complex(const complex<long double>&);
+
+    constexpr float real() const;
+    void real(float);
+    constexpr float imag() const;
+    void imag(float);
+
+    complex<float>& operator= (float);
+    complex<float>& operator+=(float);
+    complex<float>& operator-=(float);
+    complex<float>& operator*=(float);
+    complex<float>& operator/=(float);
+
+    complex<float>& operator=(const complex<float>&);
+    template<class X> complex<float>& operator= (const complex<X>&);
+    template<class X> complex<float>& operator+=(const complex<X>&);
+    template<class X> complex<float>& operator-=(const complex<X>&);
+    template<class X> complex<float>& operator*=(const complex<X>&);
+    template<class X> complex<float>& operator/=(const complex<X>&);
+};
+
+template<>
+class complex<double>
+{
+public:
+    typedef double value_type;
+
+    constexpr complex(double re = 0.0, double im = 0.0);
+    constexpr complex(const complex<float>&);
+    explicit constexpr complex(const complex<long double>&);
+
+    constexpr double real() const;
+    void real(double);
+    constexpr double imag() const;
+    void imag(double);
+
+    complex<double>& operator= (double);
+    complex<double>& operator+=(double);
+    complex<double>& operator-=(double);
+    complex<double>& operator*=(double);
+    complex<double>& operator/=(double);
+    complex<double>& operator=(const complex<double>&);
+
+    template<class X> complex<double>& operator= (const complex<X>&);
+    template<class X> complex<double>& operator+=(const complex<X>&);
+    template<class X> complex<double>& operator-=(const complex<X>&);
+    template<class X> complex<double>& operator*=(const complex<X>&);
+    template<class X> complex<double>& operator/=(const complex<X>&);
+};
+
+template<>
+class complex<long double>
+{
+public:
+    typedef long double value_type;
+
+    constexpr complex(long double re = 0.0L, long double im = 0.0L);
+    constexpr complex(const complex<float>&);
+    constexpr complex(const complex<double>&);
+
+    constexpr long double real() const;
+    void real(long double);
+    constexpr long double imag() const;
+    void imag(long double);
+
+    complex<long double>& operator=(const complex<long double>&);
+    complex<long double>& operator= (long double);
+    complex<long double>& operator+=(long double);
+    complex<long double>& operator-=(long double);
+    complex<long double>& operator*=(long double);
+    complex<long double>& operator/=(long double);
+
+    template<class X> complex<long double>& operator= (const complex<X>&);
+    template<class X> complex<long double>& operator+=(const complex<X>&);
+    template<class X> complex<long double>& operator-=(const complex<X>&);
+    template<class X> complex<long double>& operator*=(const complex<X>&);
+    template<class X> complex<long double>& operator/=(const complex<X>&);
+};
+
+// 26.3.6 operators:
+template<class T> complex<T> operator+(const complex<T>&, const complex<T>&);
+template<class T> complex<T> operator+(const complex<T>&, const T&);
+template<class T> complex<T> operator+(const T&, const complex<T>&);
+template<class T> complex<T> operator-(const complex<T>&, const complex<T>&);
+template<class T> complex<T> operator-(const complex<T>&, const T&);
+template<class T> complex<T> operator-(const T&, const complex<T>&);
+template<class T> complex<T> operator*(const complex<T>&, const complex<T>&);
+template<class T> complex<T> operator*(const complex<T>&, const T&);
+template<class T> complex<T> operator*(const T&, const complex<T>&);
+template<class T> complex<T> operator/(const complex<T>&, const complex<T>&);
+template<class T> complex<T> operator/(const complex<T>&, const T&);
+template<class T> complex<T> operator/(const T&, const complex<T>&);
+template<class T> complex<T> operator+(const complex<T>&);
+template<class T> complex<T> operator-(const complex<T>&);
+template<class T> bool operator==(const complex<T>&, const complex<T>&); // constexpr in C++14
+template<class T> bool operator==(const complex<T>&, const T&); // constexpr in C++14
+template<class T> bool operator==(const T&, const complex<T>&); // constexpr in C++14
+template<class T> bool operator!=(const complex<T>&, const complex<T>&); // constexpr in C++14
+template<class T> bool operator!=(const complex<T>&, const T&); // constexpr in C++14
+template<class T> bool operator!=(const T&, const complex<T>&); // constexpr in C++14
+
+template<class T, class charT, class traits>
+  basic_istream<charT, traits>&
+  operator>>(basic_istream<charT, traits>&, complex<T>&);
+template<class T, class charT, class traits>
+  basic_ostream<charT, traits>&
+  operator<<(basic_ostream<charT, traits>&, const complex<T>&);
+
+// 26.3.7 values:
+
+template<class T>              T real(const complex<T>&); // constexpr in C++14
+                     long double real(long double);       // constexpr in C++14
+                          double real(double);            // constexpr in C++14
+template<Integral T>      double real(T);                 // constexpr in C++14
+                          float  real(float);             // constexpr in C++14
+
+template<class T>              T imag(const complex<T>&); // constexpr in C++14
+                     long double imag(long double);       // constexpr in C++14
+                          double imag(double);            // constexpr in C++14
+template<Integral T>      double imag(T);                 // constexpr in C++14
+                          float  imag(float);             // constexpr in C++14
+
+template<class T> T abs(const complex<T>&);
+
+template<class T>              T arg(const complex<T>&);
+                     long double arg(long double);
+                          double arg(double);
+template<Integral T>      double arg(T);
+                          float  arg(float);
+
+template<class T>              T norm(const complex<T>&);
+                     long double norm(long double);
+                          double norm(double);
+template<Integral T>      double norm(T);
+                          float  norm(float);
+
+template<class T>      complex<T>           conj(const complex<T>&);
+                       complex<long double> conj(long double);
+                       complex<double>      conj(double);
+template<Integral T>   complex<double>      conj(T);
+                       complex<float>       conj(float);
+
+template<class T>    complex<T>           proj(const complex<T>&);
+                     complex<long double> proj(long double);
+                     complex<double>      proj(double);
+template<Integral T> complex<double>      proj(T);
+                     complex<float>       proj(float);
+
+template<class T> complex<T> polar(const T&, const T& = 0);
+
+// 26.3.8 transcendentals:
+template<class T> complex<T> acos(const complex<T>&);
+template<class T> complex<T> asin(const complex<T>&);
+template<class T> complex<T> atan(const complex<T>&);
+template<class T> complex<T> acosh(const complex<T>&);
+template<class T> complex<T> asinh(const complex<T>&);
+template<class T> complex<T> atanh(const complex<T>&);
+template<class T> complex<T> cos (const complex<T>&);
+template<class T> complex<T> cosh (const complex<T>&);
+template<class T> complex<T> exp (const complex<T>&);
+template<class T> complex<T> log (const complex<T>&);
+template<class T> complex<T> log10(const complex<T>&);
+
+template<class T> complex<T> pow(const complex<T>&, const T&);
+template<class T> complex<T> pow(const complex<T>&, const complex<T>&);
+template<class T> complex<T> pow(const T&, const complex<T>&);
+
+template<class T> complex<T> sin (const complex<T>&);
+template<class T> complex<T> sinh (const complex<T>&);
+template<class T> complex<T> sqrt (const complex<T>&);
+template<class T> complex<T> tan (const complex<T>&);
+template<class T> complex<T> tanh (const complex<T>&);
+
+template<class T, class charT, class traits>
+  basic_istream<charT, traits>&
+  operator>>(basic_istream<charT, traits>& is, complex<T>& x);
+
+template<class T, class charT, class traits>
+  basic_ostream<charT, traits>&
+  operator<<(basic_ostream<charT, traits>& o, const complex<T>& x);
+
+}  // std
+
+*/
+
+#include <__config>
+#include <type_traits>
+#include <stdexcept>
+#include <cmath>
+#include <sstream>
+#if defined(_LIBCPP_NO_EXCEPTIONS)
+    #include <cassert>
+#endif
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template<class _Tp> class _LIBCPP_TYPE_VIS_ONLY complex;
+
+template<class _Tp> complex<_Tp> operator*(const complex<_Tp>& __z, const complex<_Tp>& __w);
+template<class _Tp> complex<_Tp> operator/(const complex<_Tp>& __x, const complex<_Tp>& __y);
+
+template<class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY complex
+{
+public:
+    typedef _Tp value_type;
+private:
+    value_type __re_;
+    value_type __im_;
+public:
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    complex(const value_type& __re = value_type(), const value_type& __im = value_type())
+        : __re_(__re), __im_(__im) {}
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    complex(const complex<_Xp>& __c)
+        : __re_(__c.real()), __im_(__c.imag()) {}
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 value_type real() const {return __re_;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 value_type imag() const {return __im_;}
+
+    _LIBCPP_INLINE_VISIBILITY void real(value_type __re) {__re_ = __re;}
+    _LIBCPP_INLINE_VISIBILITY void imag(value_type __im) {__im_ = __im;}
+
+    _LIBCPP_INLINE_VISIBILITY complex& operator= (const value_type& __re)
+        {__re_ = __re; __im_ = value_type(); return *this;}
+    _LIBCPP_INLINE_VISIBILITY complex& operator+=(const value_type& __re) {__re_ += __re; return *this;}
+    _LIBCPP_INLINE_VISIBILITY complex& operator-=(const value_type& __re) {__re_ -= __re; return *this;}
+    _LIBCPP_INLINE_VISIBILITY complex& operator*=(const value_type& __re) {__re_ *= __re; __im_ *= __re; return *this;}
+    _LIBCPP_INLINE_VISIBILITY complex& operator/=(const value_type& __re) {__re_ /= __re; __im_ /= __re; return *this;}
+
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator= (const complex<_Xp>& __c)
+        {
+            __re_ = __c.real();
+            __im_ = __c.imag();
+            return *this;
+        }
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator+=(const complex<_Xp>& __c)
+        {
+            __re_ += __c.real();
+            __im_ += __c.imag();
+            return *this;
+        }
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator-=(const complex<_Xp>& __c)
+        {
+            __re_ -= __c.real();
+            __im_ -= __c.imag();
+            return *this;
+        }
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator*=(const complex<_Xp>& __c)
+        {
+            *this = *this * complex(__c.real(), __c.imag());
+            return *this;
+        }
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator/=(const complex<_Xp>& __c)
+        {
+            *this = *this / complex(__c.real(), __c.imag());
+            return *this;
+        }
+};
+
+template<> class _LIBCPP_TYPE_VIS_ONLY complex<double>;
+template<> class _LIBCPP_TYPE_VIS_ONLY complex<long double>;
+
+template<>
+class _LIBCPP_TYPE_VIS_ONLY complex<float>
+{
+    float __re_;
+    float __im_;
+public:
+    typedef float value_type;
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR complex(float __re = 0.0f, float __im = 0.0f)
+        : __re_(__re), __im_(__im) {}
+    explicit _LIBCPP_CONSTEXPR complex(const complex<double>& __c);
+    explicit _LIBCPP_CONSTEXPR complex(const complex<long double>& __c);
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR float real() const {return __re_;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR float imag() const {return __im_;}
+
+    _LIBCPP_INLINE_VISIBILITY void real(value_type __re) {__re_ = __re;}
+    _LIBCPP_INLINE_VISIBILITY void imag(value_type __im) {__im_ = __im;}
+
+    _LIBCPP_INLINE_VISIBILITY complex& operator= (float __re)
+        {__re_ = __re; __im_ = value_type(); return *this;}
+    _LIBCPP_INLINE_VISIBILITY complex& operator+=(float __re) {__re_ += __re; return *this;}
+    _LIBCPP_INLINE_VISIBILITY complex& operator-=(float __re) {__re_ -= __re; return *this;}
+    _LIBCPP_INLINE_VISIBILITY complex& operator*=(float __re) {__re_ *= __re; __im_ *= __re; return *this;}
+    _LIBCPP_INLINE_VISIBILITY complex& operator/=(float __re) {__re_ /= __re; __im_ /= __re; return *this;}
+
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator= (const complex<_Xp>& __c)
+        {
+            __re_ = __c.real();
+            __im_ = __c.imag();
+            return *this;
+        }
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator+=(const complex<_Xp>& __c)
+        {
+            __re_ += __c.real();
+            __im_ += __c.imag();
+            return *this;
+        }
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator-=(const complex<_Xp>& __c)
+        {
+            __re_ -= __c.real();
+            __im_ -= __c.imag();
+            return *this;
+        }
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator*=(const complex<_Xp>& __c)
+        {
+            *this = *this * complex(__c.real(), __c.imag());
+            return *this;
+        }
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator/=(const complex<_Xp>& __c)
+        {
+            *this = *this / complex(__c.real(), __c.imag());
+            return *this;
+        }
+};
+
+template<>
+class _LIBCPP_TYPE_VIS_ONLY complex<double>
+{
+    double __re_;
+    double __im_;
+public:
+    typedef double value_type;
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR complex(double __re = 0.0, double __im = 0.0)
+        : __re_(__re), __im_(__im) {}
+    _LIBCPP_CONSTEXPR complex(const complex<float>& __c);
+    explicit _LIBCPP_CONSTEXPR complex(const complex<long double>& __c);
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR double real() const {return __re_;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR double imag() const {return __im_;}
+
+    _LIBCPP_INLINE_VISIBILITY void real(value_type __re) {__re_ = __re;}
+    _LIBCPP_INLINE_VISIBILITY void imag(value_type __im) {__im_ = __im;}
+
+    _LIBCPP_INLINE_VISIBILITY complex& operator= (double __re)
+        {__re_ = __re; __im_ = value_type(); return *this;}
+    _LIBCPP_INLINE_VISIBILITY complex& operator+=(double __re) {__re_ += __re; return *this;}
+    _LIBCPP_INLINE_VISIBILITY complex& operator-=(double __re) {__re_ -= __re; return *this;}
+    _LIBCPP_INLINE_VISIBILITY complex& operator*=(double __re) {__re_ *= __re; __im_ *= __re; return *this;}
+    _LIBCPP_INLINE_VISIBILITY complex& operator/=(double __re) {__re_ /= __re; __im_ /= __re; return *this;}
+
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator= (const complex<_Xp>& __c)
+        {
+            __re_ = __c.real();
+            __im_ = __c.imag();
+            return *this;
+        }
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator+=(const complex<_Xp>& __c)
+        {
+            __re_ += __c.real();
+            __im_ += __c.imag();
+            return *this;
+        }
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator-=(const complex<_Xp>& __c)
+        {
+            __re_ -= __c.real();
+            __im_ -= __c.imag();
+            return *this;
+        }
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator*=(const complex<_Xp>& __c)
+        {
+            *this = *this * complex(__c.real(), __c.imag());
+            return *this;
+        }
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator/=(const complex<_Xp>& __c)
+        {
+            *this = *this / complex(__c.real(), __c.imag());
+            return *this;
+        }
+};
+
+template<>
+class _LIBCPP_TYPE_VIS_ONLY complex<long double>
+{
+    long double __re_;
+    long double __im_;
+public:
+    typedef long double value_type;
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR complex(long double __re = 0.0L, long double __im = 0.0L)
+        : __re_(__re), __im_(__im) {}
+    _LIBCPP_CONSTEXPR complex(const complex<float>& __c);
+    _LIBCPP_CONSTEXPR complex(const complex<double>& __c);
+
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR long double real() const {return __re_;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR long double imag() const {return __im_;}
+
+    _LIBCPP_INLINE_VISIBILITY void real(value_type __re) {__re_ = __re;}
+    _LIBCPP_INLINE_VISIBILITY void imag(value_type __im) {__im_ = __im;}
+
+    _LIBCPP_INLINE_VISIBILITY complex& operator= (long double __re)
+        {__re_ = __re; __im_ = value_type(); return *this;}
+    _LIBCPP_INLINE_VISIBILITY complex& operator+=(long double __re) {__re_ += __re; return *this;}
+    _LIBCPP_INLINE_VISIBILITY complex& operator-=(long double __re) {__re_ -= __re; return *this;}
+    _LIBCPP_INLINE_VISIBILITY complex& operator*=(long double __re) {__re_ *= __re; __im_ *= __re; return *this;}
+    _LIBCPP_INLINE_VISIBILITY complex& operator/=(long double __re) {__re_ /= __re; __im_ /= __re; return *this;}
+
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator= (const complex<_Xp>& __c)
+        {
+            __re_ = __c.real();
+            __im_ = __c.imag();
+            return *this;
+        }
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator+=(const complex<_Xp>& __c)
+        {
+            __re_ += __c.real();
+            __im_ += __c.imag();
+            return *this;
+        }
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator-=(const complex<_Xp>& __c)
+        {
+            __re_ -= __c.real();
+            __im_ -= __c.imag();
+            return *this;
+        }
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator*=(const complex<_Xp>& __c)
+        {
+            *this = *this * complex(__c.real(), __c.imag());
+            return *this;
+        }
+    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator/=(const complex<_Xp>& __c)
+        {
+            *this = *this / complex(__c.real(), __c.imag());
+            return *this;
+        }
+};
+
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+complex<float>::complex(const complex<double>& __c)
+    : __re_(__c.real()), __im_(__c.imag()) {}
+
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+complex<float>::complex(const complex<long double>& __c)
+    : __re_(__c.real()), __im_(__c.imag()) {}
+
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+complex<double>::complex(const complex<float>& __c)
+    : __re_(__c.real()), __im_(__c.imag()) {}
+
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+complex<double>::complex(const complex<long double>& __c)
+    : __re_(__c.real()), __im_(__c.imag()) {}
+
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+complex<long double>::complex(const complex<float>& __c)
+    : __re_(__c.real()), __im_(__c.imag()) {}
+
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+complex<long double>::complex(const complex<double>& __c)
+    : __re_(__c.real()), __im_(__c.imag()) {}
+
+// 26.3.6 operators:
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+operator+(const complex<_Tp>& __x, const complex<_Tp>& __y)
+{
+    complex<_Tp> __t(__x);
+    __t += __y;
+    return __t;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+operator+(const complex<_Tp>& __x, const _Tp& __y)
+{
+    complex<_Tp> __t(__x);
+    __t += __y;
+    return __t;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+operator+(const _Tp& __x, const complex<_Tp>& __y)
+{
+    complex<_Tp> __t(__y);
+    __t += __x;
+    return __t;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+operator-(const complex<_Tp>& __x, const complex<_Tp>& __y)
+{
+    complex<_Tp> __t(__x);
+    __t -= __y;
+    return __t;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+operator-(const complex<_Tp>& __x, const _Tp& __y)
+{
+    complex<_Tp> __t(__x);
+    __t -= __y;
+    return __t;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+operator-(const _Tp& __x, const complex<_Tp>& __y)
+{
+    complex<_Tp> __t(-__y);
+    __t += __x;
+    return __t;
+}
+
+template<class _Tp>
+complex<_Tp>
+operator*(const complex<_Tp>& __z, const complex<_Tp>& __w)
+{
+    _Tp __a = __z.real();
+    _Tp __b = __z.imag();
+    _Tp __c = __w.real();
+    _Tp __d = __w.imag();
+    _Tp __ac = __a * __c;
+    _Tp __bd = __b * __d;
+    _Tp __ad = __a * __d;
+    _Tp __bc = __b * __c;
+    _Tp __x = __ac - __bd;
+    _Tp __y = __ad + __bc;
+    if (isnan(__x) && isnan(__y))
+    {
+        bool __recalc = false;
+        if (isinf(__a) || isinf(__b))
+        {
+            __a = copysign(isinf(__a) ? _Tp(1) : _Tp(0), __a);
+            __b = copysign(isinf(__b) ? _Tp(1) : _Tp(0), __b);
+            if (isnan(__c))
+                __c = copysign(_Tp(0), __c);
+            if (isnan(__d))
+                __d = copysign(_Tp(0), __d);
+            __recalc = true;
+        }
+        if (isinf(__c) || isinf(__d))
+        {
+            __c = copysign(isinf(__c) ? _Tp(1) : _Tp(0), __c);
+            __d = copysign(isinf(__d) ? _Tp(1) : _Tp(0), __d);
+            if (isnan(__a))
+                __a = copysign(_Tp(0), __a);
+            if (isnan(__b))
+                __b = copysign(_Tp(0), __b);
+            __recalc = true;
+        }
+        if (!__recalc && (isinf(__ac) || isinf(__bd) ||
+                          isinf(__ad) || isinf(__bc)))
+        {
+            if (isnan(__a))
+                __a = copysign(_Tp(0), __a);
+            if (isnan(__b))
+                __b = copysign(_Tp(0), __b);
+            if (isnan(__c))
+                __c = copysign(_Tp(0), __c);
+            if (isnan(__d))
+                __d = copysign(_Tp(0), __d);
+            __recalc = true;
+        }
+        if (__recalc)
+        {
+            __x = _Tp(INFINITY) * (__a * __c - __b * __d);
+            __y = _Tp(INFINITY) * (__a * __d + __b * __c);
+        }
+    }
+    return complex<_Tp>(__x, __y);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+operator*(const complex<_Tp>& __x, const _Tp& __y)
+{
+    complex<_Tp> __t(__x);
+    __t *= __y;
+    return __t;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+operator*(const _Tp& __x, const complex<_Tp>& __y)
+{
+    complex<_Tp> __t(__y);
+    __t *= __x;
+    return __t;
+}
+
+template<class _Tp>
+complex<_Tp>
+operator/(const complex<_Tp>& __z, const complex<_Tp>& __w)
+{
+    int __ilogbw = 0;
+    _Tp __a = __z.real();
+    _Tp __b = __z.imag();
+    _Tp __c = __w.real();
+    _Tp __d = __w.imag();
+    _Tp __logbw = logb(fmax(fabs(__c), fabs(__d)));
+    if (isfinite(__logbw))
+    {
+        __ilogbw = static_cast<int>(__logbw);
+        __c = scalbn(__c, -__ilogbw);
+        __d = scalbn(__d, -__ilogbw);
+    }
+    _Tp __denom = __c * __c + __d * __d;
+    _Tp __x = scalbn((__a * __c + __b * __d) / __denom, -__ilogbw);
+    _Tp __y = scalbn((__b * __c - __a * __d) / __denom, -__ilogbw);
+    if (isnan(__x) && isnan(__y))
+    {
+        if ((__denom == _Tp(0)) && (!isnan(__a) || !isnan(__b)))
+        {
+            __x = copysign(_Tp(INFINITY), __c) * __a;
+            __y = copysign(_Tp(INFINITY), __c) * __b;
+        }
+        else if ((isinf(__a) || isinf(__b)) && isfinite(__c) && isfinite(__d))
+        {
+            __a = copysign(isinf(__a) ? _Tp(1) : _Tp(0), __a);
+            __b = copysign(isinf(__b) ? _Tp(1) : _Tp(0), __b);
+            __x = _Tp(INFINITY) * (__a * __c + __b * __d);
+            __y = _Tp(INFINITY) * (__b * __c - __a * __d);
+        }
+        else if (isinf(__logbw) && __logbw > _Tp(0) && isfinite(__a) && isfinite(__b))
+        {
+            __c = copysign(isinf(__c) ? _Tp(1) : _Tp(0), __c);
+            __d = copysign(isinf(__d) ? _Tp(1) : _Tp(0), __d);
+            __x = _Tp(0) * (__a * __c + __b * __d);
+            __y = _Tp(0) * (__b * __c - __a * __d);
+        }
+    }
+    return complex<_Tp>(__x, __y);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+operator/(const complex<_Tp>& __x, const _Tp& __y)
+{
+    return complex<_Tp>(__x.real() / __y, __x.imag() / __y);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+operator/(const _Tp& __x, const complex<_Tp>& __y)
+{
+    complex<_Tp> __t(__x);
+    __t /= __y;
+    return __t;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+operator+(const complex<_Tp>& __x)
+{
+    return __x;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+operator-(const complex<_Tp>& __x)
+{
+    return complex<_Tp>(-__x.real(), -__x.imag());
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+bool
+operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
+{
+    return __x.real() == __y.real() && __x.imag() == __y.imag();
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+bool
+operator==(const complex<_Tp>& __x, const _Tp& __y)
+{
+    return __x.real() == __y && __x.imag() == 0;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+bool
+operator==(const _Tp& __x, const complex<_Tp>& __y)
+{
+    return __x == __y.real() && 0 == __y.imag();
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+bool
+operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
+{
+    return !(__x == __y);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+bool
+operator!=(const complex<_Tp>& __x, const _Tp& __y)
+{
+    return !(__x == __y);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+bool
+operator!=(const _Tp& __x, const complex<_Tp>& __y)
+{
+    return !(__x == __y);
+}
+
+// 26.3.7 values:
+
+// real
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_Tp
+real(const complex<_Tp>& __c)
+{
+    return __c.real();
+}
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+long double
+real(long double __re)
+{
+    return __re;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+double
+real(double __re)
+{
+    return __re;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+typename enable_if
+<
+    is_integral<_Tp>::value,
+    double
+>::type
+real(_Tp  __re)
+{
+    return __re;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+float
+real(float  __re)
+{
+    return __re;
+}
+
+// imag
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_Tp
+imag(const complex<_Tp>& __c)
+{
+    return __c.imag();
+}
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+long double
+imag(long double __re)
+{
+    return 0;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+double
+imag(double __re)
+{
+    return 0;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+typename enable_if
+<
+    is_integral<_Tp>::value,
+    double
+>::type
+imag(_Tp  __re)
+{
+    return 0;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+float
+imag(float  __re)
+{
+    return 0;
+}
+
+// abs
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp
+abs(const complex<_Tp>& __c)
+{
+    return hypot(__c.real(), __c.imag());
+}
+
+// arg
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp
+arg(const complex<_Tp>& __c)
+{
+    return atan2(__c.imag(), __c.real());
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+long double
+arg(long double __re)
+{
+    return atan2l(0.L, __re);
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+double
+arg(double __re)
+{
+    return atan2(0., __re);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value,
+    double
+>::type
+arg(_Tp __re)
+{
+    return atan2(0., __re);
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+float
+arg(float __re)
+{
+    return atan2f(0.F, __re);
+}
+
+// norm
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp
+norm(const complex<_Tp>& __c)
+{
+    if (isinf(__c.real()))
+        return abs(__c.real());
+    if (isinf(__c.imag()))
+        return abs(__c.imag());
+    return __c.real() * __c.real() + __c.imag() * __c.imag();
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+long double
+norm(long double __re)
+{
+    return __re * __re;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+double
+norm(double __re)
+{
+    return __re * __re;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value,
+    double
+>::type
+norm(_Tp __re)
+{
+    return (double)__re * __re;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+float
+norm(float __re)
+{
+    return __re * __re;
+}
+
+// conj
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+conj(const complex<_Tp>& __c)
+{
+    return complex<_Tp>(__c.real(), -__c.imag());
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+complex<long double>
+conj(long double __re)
+{
+    return complex<long double>(__re);
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+complex<double>
+conj(double __re)
+{
+    return complex<double>(__re);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value,
+    complex<double>
+>::type
+conj(_Tp __re)
+{
+    return complex<double>(__re);
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+complex<float>
+conj(float __re)
+{
+    return complex<float>(__re);
+}
+
+// proj
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+proj(const complex<_Tp>& __c)
+{
+    std::complex<_Tp> __r = __c;
+    if (isinf(__c.real()) || isinf(__c.imag()))
+        __r = complex<_Tp>(INFINITY, copysign(_Tp(0), __c.imag()));
+    return __r;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+complex<long double>
+proj(long double __re)
+{
+    if (isinf(__re))
+        __re = abs(__re);
+    return complex<long double>(__re);
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+complex<double>
+proj(double __re)
+{
+    if (isinf(__re))
+        __re = abs(__re);
+    return complex<double>(__re);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_integral<_Tp>::value,
+    complex<double>
+>::type
+proj(_Tp __re)
+{
+    return complex<double>(__re);
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+complex<float>
+proj(float __re)
+{
+    if (isinf(__re))
+        __re = abs(__re);
+    return complex<float>(__re);
+}
+
+// polar
+
+template<class _Tp>
+complex<_Tp>
+polar(const _Tp& __rho, const _Tp& __theta = _Tp(0))
+{
+    if (isnan(__rho) || signbit(__rho))
+        return complex<_Tp>(_Tp(NAN), _Tp(NAN));
+    if (isnan(__theta))
+    {
+        if (isinf(__rho))
+            return complex<_Tp>(__rho, __theta);
+        return complex<_Tp>(__theta, __theta);
+    }
+    if (isinf(__theta))
+    {
+        if (isinf(__rho))
+            return complex<_Tp>(__rho, _Tp(NAN));
+        return complex<_Tp>(_Tp(NAN), _Tp(NAN));
+    }
+    _Tp __x = __rho * cos(__theta);
+    if (isnan(__x))
+        __x = 0;
+    _Tp __y = __rho * sin(__theta);
+    if (isnan(__y))
+        __y = 0;
+    return complex<_Tp>(__x, __y);
+}
+
+// log
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+log(const complex<_Tp>& __x)
+{
+    return complex<_Tp>(log(abs(__x)), arg(__x));
+}
+
+// log10
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+log10(const complex<_Tp>& __x)
+{
+    return log(__x) / log(_Tp(10));
+}
+
+// sqrt
+
+template<class _Tp>
+complex<_Tp>
+sqrt(const complex<_Tp>& __x)
+{
+    if (isinf(__x.imag()))
+        return complex<_Tp>(_Tp(INFINITY), __x.imag());
+    if (isinf(__x.real()))
+    {
+        if (__x.real() > _Tp(0))
+            return complex<_Tp>(__x.real(), isnan(__x.imag()) ? __x.imag() : copysign(_Tp(0), __x.imag()));
+        return complex<_Tp>(isnan(__x.imag()) ? __x.imag() : _Tp(0), copysign(__x.real(), __x.imag()));
+    }
+    return polar(sqrt(abs(__x)), arg(__x) / _Tp(2));
+}
+
+// exp
+
+template<class _Tp>
+complex<_Tp>
+exp(const complex<_Tp>& __x)
+{
+    _Tp __i = __x.imag();
+    if (isinf(__x.real()))
+    {
+        if (__x.real() < _Tp(0))
+        {
+            if (!isfinite(__i))
+                __i = _Tp(1);
+        }
+        else if (__i == 0 || !isfinite(__i))
+        {
+            if (isinf(__i))
+                __i = _Tp(NAN);
+            return complex<_Tp>(__x.real(), __i);
+        }
+    }
+    else if (isnan(__x.real()) && __x.imag() == 0)
+        return __x;
+    _Tp __e = exp(__x.real());
+    return complex<_Tp>(__e * cos(__i), __e * sin(__i));
+}
+
+// pow
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+pow(const complex<_Tp>& __x, const complex<_Tp>& __y)
+{
+    return exp(__y * log(__x));
+}
+
+template<class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<typename __promote<_Tp, _Up>::type>
+pow(const complex<_Tp>& __x, const complex<_Up>& __y)
+{
+    typedef complex<typename __promote<_Tp, _Up>::type> result_type;
+    return _VSTD::pow(result_type(__x), result_type(__y));
+}
+
+template<class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_arithmetic<_Up>::value,
+    complex<typename __promote<_Tp, _Up>::type>
+>::type
+pow(const complex<_Tp>& __x, const _Up& __y)
+{
+    typedef complex<typename __promote<_Tp, _Up>::type> result_type;
+    return _VSTD::pow(result_type(__x), result_type(__y));
+}
+
+template<class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_arithmetic<_Tp>::value,
+    complex<typename __promote<_Tp, _Up>::type>
+>::type
+pow(const _Tp& __x, const complex<_Up>& __y)
+{
+    typedef complex<typename __promote<_Tp, _Up>::type> result_type;
+    return _VSTD::pow(result_type(__x), result_type(__y));
+}
+
+// asinh
+
+template<class _Tp>
+complex<_Tp>
+asinh(const complex<_Tp>& __x)
+{
+    const _Tp __pi(atan2(+0., -0.));
+    if (isinf(__x.real()))
+    {
+        if (isnan(__x.imag()))
+            return __x;
+        if (isinf(__x.imag()))
+            return complex<_Tp>(__x.real(), copysign(__pi * _Tp(0.25), __x.imag()));
+        return complex<_Tp>(__x.real(), copysign(_Tp(0), __x.imag()));
+    }
+    if (isnan(__x.real()))
+    {
+        if (isinf(__x.imag()))
+            return complex<_Tp>(__x.imag(), __x.real());
+        if (__x.imag() == 0)
+            return __x;
+        return complex<_Tp>(__x.real(), __x.real());
+    }
+    if (isinf(__x.imag()))
+        return complex<_Tp>(copysign(__x.imag(), __x.real()), copysign(__pi/_Tp(2), __x.imag()));
+    complex<_Tp> __z = log(__x + sqrt(pow(__x, _Tp(2)) + _Tp(1)));
+    return complex<_Tp>(copysign(__z.real(), __x.real()), copysign(__z.imag(), __x.imag()));
+}
+
+// acosh
+
+template<class _Tp>
+complex<_Tp>
+acosh(const complex<_Tp>& __x)
+{
+    const _Tp __pi(atan2(+0., -0.));
+    if (isinf(__x.real()))
+    {
+        if (isnan(__x.imag()))
+            return complex<_Tp>(abs(__x.real()), __x.imag());
+        if (isinf(__x.imag()))
+        {
+            if (__x.real() > 0)
+                return complex<_Tp>(__x.real(), copysign(__pi * _Tp(0.25), __x.imag()));
+            else
+                return complex<_Tp>(-__x.real(), copysign(__pi * _Tp(0.75), __x.imag()));
+        }
+        if (__x.real() < 0)
+            return complex<_Tp>(-__x.real(), copysign(__pi, __x.imag()));
+        return complex<_Tp>(__x.real(), copysign(_Tp(0), __x.imag()));
+    }
+    if (isnan(__x.real()))
+    {
+        if (isinf(__x.imag()))
+            return complex<_Tp>(abs(__x.imag()), __x.real());
+        return complex<_Tp>(__x.real(), __x.real());
+    }
+    if (isinf(__x.imag()))
+        return complex<_Tp>(abs(__x.imag()), copysign(__pi/_Tp(2), __x.imag()));
+    complex<_Tp> __z = log(__x + sqrt(pow(__x, _Tp(2)) - _Tp(1)));
+    return complex<_Tp>(copysign(__z.real(), _Tp(0)), copysign(__z.imag(), __x.imag()));
+}
+
+// atanh
+
+template<class _Tp>
+complex<_Tp>
+atanh(const complex<_Tp>& __x)
+{
+    const _Tp __pi(atan2(+0., -0.));
+    if (isinf(__x.imag()))
+    {
+        return complex<_Tp>(copysign(_Tp(0), __x.real()), copysign(__pi/_Tp(2), __x.imag()));
+    }
+    if (isnan(__x.imag()))
+    {
+        if (isinf(__x.real()) || __x.real() == 0)
+            return complex<_Tp>(copysign(_Tp(0), __x.real()), __x.imag());
+        return complex<_Tp>(__x.imag(), __x.imag());
+    }
+    if (isnan(__x.real()))
+    {
+        return complex<_Tp>(__x.real(), __x.real());
+    }
+    if (isinf(__x.real()))
+    {
+        return complex<_Tp>(copysign(_Tp(0), __x.real()), copysign(__pi/_Tp(2), __x.imag()));
+    }
+    if (abs(__x.real()) == _Tp(1) && __x.imag() == _Tp(0))
+    {
+        return complex<_Tp>(copysign(_Tp(INFINITY), __x.real()), copysign(_Tp(0), __x.imag()));
+    }
+    complex<_Tp> __z = log((_Tp(1) + __x) / (_Tp(1) - __x)) / _Tp(2);
+    return complex<_Tp>(copysign(__z.real(), __x.real()), copysign(__z.imag(), __x.imag()));
+}
+
+// sinh
+
+template<class _Tp>
+complex<_Tp>
+sinh(const complex<_Tp>& __x)
+{
+    if (isinf(__x.real()) && !isfinite(__x.imag()))
+        return complex<_Tp>(__x.real(), _Tp(NAN));
+    if (__x.real() == 0 && !isfinite(__x.imag()))
+        return complex<_Tp>(__x.real(), _Tp(NAN));
+    if (__x.imag() == 0 && !isfinite(__x.real()))
+        return __x;
+    return complex<_Tp>(sinh(__x.real()) * cos(__x.imag()), cosh(__x.real()) * sin(__x.imag()));
+}
+
+// cosh
+
+template<class _Tp>
+complex<_Tp>
+cosh(const complex<_Tp>& __x)
+{
+    if (isinf(__x.real()) && !isfinite(__x.imag()))
+        return complex<_Tp>(abs(__x.real()), _Tp(NAN));
+    if (__x.real() == 0 && !isfinite(__x.imag()))
+        return complex<_Tp>(_Tp(NAN), __x.real());
+    if (__x.real() == 0 && __x.imag() == 0)
+        return complex<_Tp>(_Tp(1), __x.imag());
+    if (__x.imag() == 0 && !isfinite(__x.real()))
+        return complex<_Tp>(abs(__x.real()), __x.imag());
+    return complex<_Tp>(cosh(__x.real()) * cos(__x.imag()), sinh(__x.real()) * sin(__x.imag()));
+}
+
+// tanh
+
+template<class _Tp>
+complex<_Tp>
+tanh(const complex<_Tp>& __x)
+{
+    if (isinf(__x.real()))
+    {
+        if (!isfinite(__x.imag()))
+            return complex<_Tp>(_Tp(1), _Tp(0));
+        return complex<_Tp>(_Tp(1), copysign(_Tp(0), sin(_Tp(2) * __x.imag())));
+    }
+    if (isnan(__x.real()) && __x.imag() == 0)
+        return __x;
+    _Tp __2r(_Tp(2) * __x.real());
+    _Tp __2i(_Tp(2) * __x.imag());
+    _Tp __d(cosh(__2r) + cos(__2i));
+    _Tp __2rsh(sinh(__2r));
+    if (isinf(__2rsh) && isinf(__d))
+        return complex<_Tp>(__2rsh > _Tp(0) ? _Tp(1) : _Tp(-1),
+                            __2i > _Tp(0) ? _Tp(0) : _Tp(-0.));
+    return  complex<_Tp>(__2rsh/__d, sin(__2i)/__d);
+}
+
+// asin
+
+template<class _Tp>
+complex<_Tp>
+asin(const complex<_Tp>& __x)
+{
+    complex<_Tp> __z = asinh(complex<_Tp>(-__x.imag(), __x.real()));
+    return complex<_Tp>(__z.imag(), -__z.real());
+}
+
+// acos
+
+template<class _Tp>
+complex<_Tp>
+acos(const complex<_Tp>& __x)
+{
+    const _Tp __pi(atan2(+0., -0.));
+    if (isinf(__x.real()))
+    {
+        if (isnan(__x.imag()))
+            return complex<_Tp>(__x.imag(), __x.real());
+        if (isinf(__x.imag()))
+        {
+            if (__x.real() < _Tp(0))
+                return complex<_Tp>(_Tp(0.75) * __pi, -__x.imag());
+            return complex<_Tp>(_Tp(0.25) * __pi, -__x.imag());
+        }
+        if (__x.real() < _Tp(0))
+            return complex<_Tp>(__pi, signbit(__x.imag()) ? -__x.real() : __x.real());
+        return complex<_Tp>(_Tp(0), signbit(__x.imag()) ? __x.real() : -__x.real());
+    }
+    if (isnan(__x.real()))
+    {
+        if (isinf(__x.imag()))
+            return complex<_Tp>(__x.real(), -__x.imag());
+        return complex<_Tp>(__x.real(), __x.real());
+    }
+    if (isinf(__x.imag()))
+        return complex<_Tp>(__pi/_Tp(2), -__x.imag());
+    if (__x.real() == 0)
+        return complex<_Tp>(__pi/_Tp(2), -__x.imag());
+    complex<_Tp> __z = log(__x + sqrt(pow(__x, _Tp(2)) - _Tp(1)));
+    if (signbit(__x.imag()))
+        return complex<_Tp>(abs(__z.imag()), abs(__z.real()));
+    return complex<_Tp>(abs(__z.imag()), -abs(__z.real()));
+}
+
+// atan
+
+template<class _Tp>
+complex<_Tp>
+atan(const complex<_Tp>& __x)
+{
+    complex<_Tp> __z = atanh(complex<_Tp>(-__x.imag(), __x.real()));
+    return complex<_Tp>(__z.imag(), -__z.real());
+}
+
+// sin
+
+template<class _Tp>
+complex<_Tp>
+sin(const complex<_Tp>& __x)
+{
+    complex<_Tp> __z = sinh(complex<_Tp>(-__x.imag(), __x.real()));
+    return complex<_Tp>(__z.imag(), -__z.real());
+}
+
+// cos
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+complex<_Tp>
+cos(const complex<_Tp>& __x)
+{
+    return cosh(complex<_Tp>(-__x.imag(), __x.real()));
+}
+
+// tan
+
+template<class _Tp>
+complex<_Tp>
+tan(const complex<_Tp>& __x)
+{
+    complex<_Tp> __z = tanh(complex<_Tp>(-__x.imag(), __x.real()));
+    return complex<_Tp>(__z.imag(), -__z.real());
+}
+
+template<class _Tp, class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is, complex<_Tp>& __x)
+{
+    if (__is.good())
+    {
+        ws(__is);
+        if (__is.peek() == _CharT('('))
+        {
+            __is.get();
+            _Tp __r;
+            __is >> __r;
+            if (!__is.fail())
+            {
+                ws(__is);
+                _CharT __c = __is.peek();
+                if (__c == _CharT(','))
+                {
+                    __is.get();
+                    _Tp __i;
+                    __is >> __i;
+                    if (!__is.fail())
+                    {
+                        ws(__is);
+                        __c = __is.peek();
+                        if (__c == _CharT(')'))
+                        {
+                            __is.get();
+                            __x = complex<_Tp>(__r, __i);
+                        }
+                        else
+                            __is.setstate(ios_base::failbit);
+                    }
+                    else
+                        __is.setstate(ios_base::failbit);
+                }
+                else if (__c == _CharT(')'))
+                {
+                    __is.get();
+                    __x = complex<_Tp>(__r, _Tp(0));
+                }
+                else
+                    __is.setstate(ios_base::failbit);
+            }
+            else
+                __is.setstate(ios_base::failbit);
+        }
+        else
+        {
+            _Tp __r;
+            __is >> __r;
+            if (!__is.fail())
+                __x = complex<_Tp>(__r, _Tp(0));
+            else
+                __is.setstate(ios_base::failbit);
+        }
+    }
+    else
+        __is.setstate(ios_base::failbit);
+    return __is;
+}
+
+template<class _Tp, class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os, const complex<_Tp>& __x)
+{
+    basic_ostringstream<_CharT, _Traits> __s;
+    __s.flags(__os.flags());
+    __s.imbue(__os.getloc());
+    __s.precision(__os.precision());
+    __s << '(' << __x.real() << ',' << __x.imag() << ')';
+    return __os << __s.str();
+}
+
+#if _LIBCPP_STD_VER > 11 
+// Literal suffix for complex number literals [complex.literals]
+inline namespace literals
+{ 
+  inline namespace complex_literals
+  {
+    constexpr complex<long double> operator""il(long double __im)
+    {
+        return { 0.0l, __im };
+    }
+
+    constexpr complex<long double> operator""il(unsigned long long __im)
+    {
+        return { 0.0l, static_cast<long double>(__im) };
+    }
+
+
+    constexpr complex<double> operator""i(long double __im)
+    {
+        return { 0.0, static_cast<double>(__im) };
+    }
+
+    constexpr complex<double> operator""i(unsigned long long __im)
+    {
+        return { 0.0, static_cast<double>(__im) };
+    }
+
+
+    constexpr complex<float> operator""if(long double __im)
+    {
+        return { 0.0f, static_cast<float>(__im) };
+    }
+
+    constexpr complex<float> operator""if(unsigned long long __im)
+    {
+        return { 0.0f, static_cast<float>(__im) };
+    }
+  }
+}
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_COMPLEX

diff --git a/libcxx/include/complex.h b/libcxx/include/complex.h
new file mode 100644
index 0000000..7003d31
--- /dev/null
+++ b/libcxx/include/complex.h

@@ -0,0 +1,35 @@
+// -*- C++ -*-
+//===--------------------------- complex.h --------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_COMPLEX_H
+#define _LIBCPP_COMPLEX_H
+
+/*
+    complex.h synopsis
+
+#include <ccomplex>
+
+*/
+
+#ifdef __cplusplus
+
+#include <ccomplex>
+
+#else  // __cplusplus
+
+#include_next <complex.h>
+
+#endif  // __cplusplus
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#endif  // _LIBCPP_COMPLEX_H

diff --git a/libcxx/include/condition_variable b/libcxx/include/condition_variable
new file mode 100644
index 0000000..1af2484
--- /dev/null
+++ b/libcxx/include/condition_variable

@@ -0,0 +1,260 @@
+// -*- C++ -*-
+//===---------------------- condition_variable ----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CONDITION_VARIABLE
+#define _LIBCPP_CONDITION_VARIABLE
+
+/*
+    condition_variable synopsis
+
+namespace std
+{
+
+enum class cv_status { no_timeout, timeout };
+
+class condition_variable
+{
+public:
+    condition_variable();
+    ~condition_variable();
+
+    condition_variable(const condition_variable&) = delete;
+    condition_variable& operator=(const condition_variable&) = delete;
+
+    void notify_one() noexcept;
+    void notify_all() noexcept;
+
+    void wait(unique_lock<mutex>& lock);
+    template <class Predicate>
+        void wait(unique_lock<mutex>& lock, Predicate pred);
+
+    template <class Clock, class Duration>
+        cv_status
+        wait_until(unique_lock<mutex>& lock,
+                   const chrono::time_point<Clock, Duration>& abs_time);
+
+    template <class Clock, class Duration, class Predicate>
+        bool
+        wait_until(unique_lock<mutex>& lock,
+                   const chrono::time_point<Clock, Duration>& abs_time,
+                   Predicate pred);
+
+    template <class Rep, class Period>
+        cv_status
+        wait_for(unique_lock<mutex>& lock,
+                 const chrono::duration<Rep, Period>& rel_time);
+
+    template <class Rep, class Period, class Predicate>
+        bool
+        wait_for(unique_lock<mutex>& lock,
+                 const chrono::duration<Rep, Period>& rel_time,
+                 Predicate pred);
+
+    typedef pthread_cond_t* native_handle_type;
+    native_handle_type native_handle();
+};
+
+void notify_all_at_thread_exit(condition_variable& cond, unique_lock<mutex> lk);
+
+class condition_variable_any
+{
+public:
+    condition_variable_any();
+    ~condition_variable_any();
+
+    condition_variable_any(const condition_variable_any&) = delete;
+    condition_variable_any& operator=(const condition_variable_any&) = delete;
+
+    void notify_one() noexcept;
+    void notify_all() noexcept;
+
+    template <class Lock>
+        void wait(Lock& lock);
+    template <class Lock, class Predicate>
+        void wait(Lock& lock, Predicate pred);
+
+    template <class Lock, class Clock, class Duration>
+        cv_status
+        wait_until(Lock& lock,
+                   const chrono::time_point<Clock, Duration>& abs_time);
+
+    template <class Lock, class Clock, class Duration, class Predicate>
+        bool
+        wait_until(Lock& lock,
+                   const chrono::time_point<Clock, Duration>& abs_time,
+                   Predicate pred);
+
+    template <class Lock, class Rep, class Period>
+        cv_status
+        wait_for(Lock& lock,
+                 const chrono::duration<Rep, Period>& rel_time);
+
+    template <class Lock, class Rep, class Period, class Predicate>
+        bool
+        wait_for(Lock& lock,
+                 const chrono::duration<Rep, Period>& rel_time,
+                 Predicate pred);
+};
+
+}  // std
+
+*/
+
+#include <__config>
+#include <__mutex_base>
+#include <memory>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#ifndef _LIBCPP_HAS_NO_THREADS
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+class _LIBCPP_TYPE_VIS condition_variable_any
+{
+    condition_variable __cv_;
+    shared_ptr<mutex>  __mut_;
+public:
+    condition_variable_any();
+
+    void notify_one() _NOEXCEPT;
+    void notify_all() _NOEXCEPT;
+
+    template <class _Lock>
+        void wait(_Lock& __lock);
+    template <class _Lock, class _Predicate>
+        void wait(_Lock& __lock, _Predicate __pred);
+
+    template <class _Lock, class _Clock, class _Duration>
+        cv_status
+        wait_until(_Lock& __lock,
+                   const chrono::time_point<_Clock, _Duration>& __t);
+
+    template <class _Lock, class _Clock, class _Duration, class _Predicate>
+        bool
+        wait_until(_Lock& __lock,
+                   const chrono::time_point<_Clock, _Duration>& __t,
+                   _Predicate __pred);
+
+    template <class _Lock, class _Rep, class _Period>
+        cv_status
+        wait_for(_Lock& __lock,
+                 const chrono::duration<_Rep, _Period>& __d);
+
+    template <class _Lock, class _Rep, class _Period, class _Predicate>
+        bool
+        wait_for(_Lock& __lock,
+                 const chrono::duration<_Rep, _Period>& __d,
+                 _Predicate __pred);
+};
+
+inline _LIBCPP_INLINE_VISIBILITY
+condition_variable_any::condition_variable_any()
+    : __mut_(make_shared<mutex>()) {}
+
+inline _LIBCPP_INLINE_VISIBILITY
+void
+condition_variable_any::notify_one() _NOEXCEPT
+{
+    {lock_guard<mutex> __lx(*__mut_);}
+    __cv_.notify_one();
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+void
+condition_variable_any::notify_all() _NOEXCEPT
+{
+    {lock_guard<mutex> __lx(*__mut_);}
+    __cv_.notify_all();
+}
+
+struct __lock_external
+{
+    template <class _Lock>
+    void operator()(_Lock* __m) {__m->lock();}
+};
+
+template <class _Lock>
+void
+condition_variable_any::wait(_Lock& __lock)
+{
+    shared_ptr<mutex> __mut = __mut_;
+    unique_lock<mutex> __lk(*__mut);
+    __lock.unlock();
+    unique_ptr<_Lock, __lock_external> __lxx(&__lock);
+    lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock);
+    __cv_.wait(__lk);
+}  // __mut_.unlock(), __lock.lock()
+
+template <class _Lock, class _Predicate>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+condition_variable_any::wait(_Lock& __lock, _Predicate __pred)
+{
+    while (!__pred())
+        wait(__lock);
+}
+
+template <class _Lock, class _Clock, class _Duration>
+cv_status
+condition_variable_any::wait_until(_Lock& __lock,
+                                   const chrono::time_point<_Clock, _Duration>& __t)
+{
+    shared_ptr<mutex> __mut = __mut_;
+    unique_lock<mutex> __lk(*__mut);
+    __lock.unlock();
+    unique_ptr<_Lock, __lock_external> __lxx(&__lock);
+    lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock);
+    return __cv_.wait_until(__lk, __t);
+}  // __mut_.unlock(), __lock.lock()
+
+template <class _Lock, class _Clock, class _Duration, class _Predicate>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+condition_variable_any::wait_until(_Lock& __lock,
+                                   const chrono::time_point<_Clock, _Duration>& __t,
+                                   _Predicate __pred)
+{
+    while (!__pred())
+        if (wait_until(__lock, __t) == cv_status::timeout)
+            return __pred();
+    return true;
+}
+
+template <class _Lock, class _Rep, class _Period>
+inline _LIBCPP_INLINE_VISIBILITY
+cv_status
+condition_variable_any::wait_for(_Lock& __lock,
+                                 const chrono::duration<_Rep, _Period>& __d)
+{
+    return wait_until(__lock, chrono::steady_clock::now() + __d);
+}
+
+template <class _Lock, class _Rep, class _Period, class _Predicate>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+condition_variable_any::wait_for(_Lock& __lock,
+                                 const chrono::duration<_Rep, _Period>& __d,
+                                 _Predicate __pred)
+{
+    return wait_until(__lock, chrono::steady_clock::now() + __d,
+                      _VSTD::move(__pred));
+}
+
+_LIBCPP_FUNC_VIS
+void notify_all_at_thread_exit(condition_variable& cond, unique_lock<mutex> lk);
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // !_LIBCPP_HAS_NO_THREADS
+
+#endif  // _LIBCPP_CONDITION_VARIABLE

diff --git a/libcxx/include/csetjmp b/libcxx/include/csetjmp
new file mode 100644
index 0000000..d0b2c07
--- /dev/null
+++ b/libcxx/include/csetjmp

@@ -0,0 +1,52 @@
+// -*- C++ -*-
+//===--------------------------- csetjmp ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CSETJMP
+#define _LIBCPP_CSETJMP
+
+/*
+    csetjmp synopsis
+
+Macros:
+
+    setjmp
+
+namespace std
+{
+
+Types:
+
+    jmp_buf
+
+void longjmp(jmp_buf env, int val);
+
+}  // std
+
+*/
+
+#include <__config>
+#include <setjmp.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#ifndef setjmp
+#define setjmp(env) setjmp(env)
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+using ::jmp_buf;
+using ::longjmp;
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CSETJMP

diff --git a/libcxx/include/csignal b/libcxx/include/csignal
new file mode 100644
index 0000000..9728266
--- /dev/null
+++ b/libcxx/include/csignal

@@ -0,0 +1,58 @@
+// -*- C++ -*-
+//===--------------------------- csignal ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CSIGNAL
+#define _LIBCPP_CSIGNAL
+
+/*
+    csignal synopsis
+
+Macros:
+
+    SIG_DFL
+    SIG_ERR
+    SIG_IGN
+    SIGABRT
+    SIGFPE
+    SIGILL
+    SIGINT
+    SIGSEGV
+    SIGTERM
+
+namespace std
+{
+
+Types:
+
+    sig_atomic_t
+
+void (*signal(int sig, void (*func)(int)))(int);
+int raise(int sig);
+
+}  // std
+
+*/
+
+#include <__config>
+#include <signal.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+using ::sig_atomic_t;
+using ::signal;
+using ::raise;
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CSIGNAL

diff --git a/libcxx/include/cstdarg b/libcxx/include/cstdarg
new file mode 100644
index 0000000..c8b6999
--- /dev/null
+++ b/libcxx/include/cstdarg

@@ -0,0 +1,48 @@
+// -*- C++ -*-
+//===--------------------------- cstdarg ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CSTDARG
+#define _LIBCPP_CSTDARG
+
+/*
+    cstdarg synopsis
+
+Macros:
+
+    type va_arg(va_list ap, type);
+    void va_copy(va_list dest, va_list src);  // C99
+    void va_end(va_list ap);
+    void va_start(va_list ap, parmN);
+
+namespace std
+{
+
+Types:
+
+    va_list
+
+}  // std
+
+*/
+
+#include <__config>
+#include <stdarg.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+using ::va_list;
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CSTDARG

diff --git a/libcxx/include/cstdbool b/libcxx/include/cstdbool
new file mode 100644
index 0000000..2c764a6
--- /dev/null
+++ b/libcxx/include/cstdbool

@@ -0,0 +1,32 @@
+// -*- C++ -*-
+//===--------------------------- cstdbool ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CSTDBOOL
+#define _LIBCPP_CSTDBOOL
+
+/*
+    cstdbool synopsis
+
+Macros:
+
+    __bool_true_false_are_defined
+
+*/
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#undef __bool_true_false_are_defined
+#define __bool_true_false_are_defined 1
+
+#endif  // _LIBCPP_CSTDBOOL

diff --git a/libcxx/include/cstddef b/libcxx/include/cstddef
new file mode 100644
index 0000000..c3ca64a
--- /dev/null
+++ b/libcxx/include/cstddef

@@ -0,0 +1,102 @@
+// -*- C++ -*-
+//===--------------------------- cstddef ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CSTDDEF
+#define _LIBCPP_CSTDDEF
+
+/*
+    cstddef synopsis
+
+Macros:
+
+    offsetof(type,member-designator)
+    NULL
+
+namespace std
+{
+
+Types:
+
+    ptrdiff_t
+    size_t
+    max_align_t
+    nullptr_t
+
+}  // std
+
+*/
+
+#include <__config>
+
+#include <stddef.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+using ::ptrdiff_t;
+using ::size_t;
+
+#if defined(__CLANG_MAX_ALIGN_T_DEFINED) || defined(_GCC_MAX_ALIGN_T)
+// Re-use the compiler's <stddef.h> max_align_t where possible.
+using ::max_align_t;
+#else
+typedef long double max_align_t;
+#endif
+
+#ifdef _LIBCPP_HAS_NO_NULLPTR
+
+struct _LIBCPP_TYPE_VIS_ONLY nullptr_t
+{
+    void* __lx;
+
+    struct __nat {int __for_bool_;};
+
+    _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t() : __lx(0) {}
+    _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t(int __nat::*) : __lx(0) {}
+
+    _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR operator int __nat::*() const {return 0;}
+
+    template <class _Tp>
+        _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR
+        operator _Tp* () const {return 0;}
+
+    template <class _Tp, class _Up>
+        _LIBCPP_ALWAYS_INLINE
+        operator _Tp _Up::* () const {return 0;}
+
+    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator==(nullptr_t, nullptr_t) {return true;}
+    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator!=(nullptr_t, nullptr_t) {return false;}
+    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator<(nullptr_t, nullptr_t) {return false;}
+    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator<=(nullptr_t, nullptr_t) {return true;}
+    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator>(nullptr_t, nullptr_t) {return false;}
+    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator>=(nullptr_t, nullptr_t) {return true;}
+};
+
+inline _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t __get_nullptr_t() {return nullptr_t(0);}
+
+#define nullptr _VSTD::__get_nullptr_t()
+
+#endif  // _LIBCPP_HAS_NO_NULLPTR
+
+_LIBCPP_END_NAMESPACE_STD
+
+#ifndef _LIBCPP_HAS_NO_NULLPTR
+
+namespace std
+{
+    typedef decltype(nullptr) nullptr_t;
+}
+
+#endif  // _LIBCPP_HAS_NO_NULLPTR
+
+#endif  // _LIBCPP_CSTDDEF

diff --git a/libcxx/include/cstdint b/libcxx/include/cstdint
new file mode 100644
index 0000000..7a187d3
--- /dev/null
+++ b/libcxx/include/cstdint

@@ -0,0 +1,191 @@
+// -*- C++ -*-
+//===--------------------------- cstdint ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CSTDINT
+#define _LIBCPP_CSTDINT
+
+/*
+    cstdint synopsis
+
+Macros:
+
+    INT8_MIN
+    INT16_MIN
+    INT32_MIN
+    INT64_MIN
+
+    INT8_MAX
+    INT16_MAX
+    INT32_MAX
+    INT64_MAX
+
+    UINT8_MAX
+    UINT16_MAX
+    UINT32_MAX
+    UINT64_MAX
+
+    INT_LEAST8_MIN
+    INT_LEAST16_MIN
+    INT_LEAST32_MIN
+    INT_LEAST64_MIN
+
+    INT_LEAST8_MAX
+    INT_LEAST16_MAX
+    INT_LEAST32_MAX
+    INT_LEAST64_MAX
+
+    UINT_LEAST8_MAX
+    UINT_LEAST16_MAX
+    UINT_LEAST32_MAX
+    UINT_LEAST64_MAX
+
+    INT_FAST8_MIN
+    INT_FAST16_MIN
+    INT_FAST32_MIN
+    INT_FAST64_MIN
+
+    INT_FAST8_MAX
+    INT_FAST16_MAX
+    INT_FAST32_MAX
+    INT_FAST64_MAX
+
+    UINT_FAST8_MAX
+    UINT_FAST16_MAX
+    UINT_FAST32_MAX
+    UINT_FAST64_MAX
+
+    INTPTR_MIN
+    INTPTR_MAX
+    UINTPTR_MAX
+
+    INTMAX_MIN
+    INTMAX_MAX
+
+    UINTMAX_MAX
+
+    PTRDIFF_MIN
+    PTRDIFF_MAX
+
+    SIG_ATOMIC_MIN
+    SIG_ATOMIC_MAX
+
+    SIZE_MAX
+
+    WCHAR_MIN
+    WCHAR_MAX
+
+    WINT_MIN
+    WINT_MAX
+
+    INT8_C(value)
+    INT16_C(value)
+    INT32_C(value)
+    INT64_C(value)
+
+    UINT8_C(value)
+    UINT16_C(value)
+    UINT32_C(value)
+    UINT64_C(value)
+
+    INTMAX_C(value)
+    UINTMAX_C(value)
+
+namespace std
+{
+
+Types:
+
+    int8_t
+    int16_t
+    int32_t
+    int64_t
+
+    uint8_t
+    uint16_t
+    uint32_t
+    uint64_t
+
+    int_least8_t
+    int_least16_t
+    int_least32_t
+    int_least64_t
+
+    uint_least8_t
+    uint_least16_t
+    uint_least32_t
+    uint_least64_t
+
+    int_fast8_t
+    int_fast16_t
+    int_fast32_t
+    int_fast64_t
+
+    uint_fast8_t
+    uint_fast16_t
+    uint_fast32_t
+    uint_fast64_t
+
+    intptr_t
+    uintptr_t
+
+    intmax_t
+    uintmax_t
+
+}  // std
+*/
+
+#include <__config>
+#include <stdint.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+using::int8_t;
+using::int16_t;
+using::int32_t;
+using::int64_t;
+
+using::uint8_t;
+using::uint16_t;
+using::uint32_t;
+using::uint64_t;
+
+using::int_least8_t;
+using::int_least16_t;
+using::int_least32_t;
+using::int_least64_t;
+
+using::uint_least8_t;
+using::uint_least16_t;
+using::uint_least32_t;
+using::uint_least64_t;
+
+using::int_fast8_t;
+using::int_fast16_t;
+using::int_fast32_t;
+using::int_fast64_t;
+
+using::uint_fast8_t;
+using::uint_fast16_t;
+using::uint_fast32_t;
+using::uint_fast64_t;
+
+using::intptr_t;
+using::uintptr_t;
+
+using::intmax_t;
+using::uintmax_t;
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CSTDINT

diff --git a/libcxx/include/cstdio b/libcxx/include/cstdio
new file mode 100644
index 0000000..d8ba6c2
--- /dev/null
+++ b/libcxx/include/cstdio

@@ -0,0 +1,209 @@
+// -*- C++ -*-
+//===---------------------------- cstdio ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CSTDIO
+#define _LIBCPP_CSTDIO
+
+/*
+    cstdio synopsis
+
+Macros:
+
+    BUFSIZ
+    EOF
+    FILENAME_MAX
+    FOPEN_MAX
+    L_tmpnam
+    NULL
+    SEEK_CUR
+    SEEK_END
+    SEEK_SET
+    TMP_MAX
+    _IOFBF
+    _IOLBF
+    _IONBF
+    stderr
+    stdin
+    stdout
+
+namespace std
+{
+
+Types:
+
+FILE
+fpos_t
+size_t
+
+int remove(const char* filename);
+int rename(const char* old, const char* new);
+FILE* tmpfile(void);
+char* tmpnam(char* s);
+int fclose(FILE* stream);
+int fflush(FILE* stream);
+FILE* fopen(const char* restrict filename, const char* restrict mode);
+FILE* freopen(const char* restrict filename, const char * restrict mode,
+              FILE * restrict stream);
+void setbuf(FILE* restrict stream, char* restrict buf);
+int setvbuf(FILE* restrict stream, char* restrict buf, int mode, size_t size);
+int fprintf(FILE* restrict stream, const char* restrict format, ...);
+int fscanf(FILE* restrict stream, const char * restrict format, ...);
+int printf(const char* restrict format, ...);
+int scanf(const char* restrict format, ...);
+int snprintf(char* restrict s, size_t n, const char* restrict format, ...);    // C99
+int sprintf(char* restrict s, const char* restrict format, ...);
+int sscanf(const char* restrict s, const char* restrict format, ...);
+int vfprintf(FILE* restrict stream, const char* restrict format, va_list arg);
+int vfscanf(FILE* restrict stream, const char* restrict format, va_list arg);  // C99
+int vprintf(const char* restrict format, va_list arg);
+int vscanf(const char* restrict format, va_list arg);                          // C99
+int vsnprintf(char* restrict s, size_t n, const char* restrict format,         // C99
+              va_list arg);
+int vsprintf(char* restrict s, const char* restrict format, va_list arg);
+int vsscanf(const char* restrict s, const char* restrict format, va_list arg); // C99
+int fgetc(FILE* stream);
+char* fgets(char* restrict s, int n, FILE* restrict stream);
+int fputc(int c, FILE* stream);
+int fputs(const char* restrict s, FILE* restrict stream);
+int getc(FILE* stream);
+int getchar(void);
+char* gets(char* s);  // removed in C++14
+int putc(int c, FILE* stream);
+int putchar(int c);
+int puts(const char* s);
+int ungetc(int c, FILE* stream);
+size_t fread(void* restrict ptr, size_t size, size_t nmemb,
+             FILE* restrict stream);
+size_t fwrite(const void* restrict ptr, size_t size, size_t nmemb,
+              FILE* restrict stream);
+int fgetpos(FILE* restrict stream, fpos_t* restrict pos);
+int fseek(FILE* stream, long offset, int whence);
+int fsetpos(FILE*stream, const fpos_t* pos);
+long ftell(FILE* stream);
+void rewind(FILE* stream);
+void clearerr(FILE* stream);
+int feof(FILE* stream);
+int ferror(FILE* stream);
+void perror(const char* s);
+
+}  // std
+*/
+
+#include <__config>
+#include <stdio.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+// snprintf
+#if defined(_LIBCPP_MSVCRT)
+#include "support/win32/support.h"
+#endif
+
+#ifdef getc
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_getc(FILE* __stream) {return getc(__stream);}
+#undef getc
+inline _LIBCPP_INLINE_VISIBILITY int getc(FILE* __stream) {return __libcpp_getc(__stream);}
+#endif  // getc
+
+#ifdef putc
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_putc(int __c, FILE* __stream) {return putc(__c, __stream);}
+#undef putc
+inline _LIBCPP_INLINE_VISIBILITY int putc(int __c, FILE* __stream) {return __libcpp_putc(__c, __stream);}
+#endif  // putc
+
+#ifdef clearerr
+inline _LIBCPP_INLINE_VISIBILITY void __libcpp_clearerr(FILE* __stream) { return clearerr(__stream); }
+#undef clearerr
+inline _LIBCPP_INLINE_VISIBILITY void clearerr(FILE* __stream) { return __libcpp_clearerr(__stream); }
+#endif  // clearerr
+
+#ifdef feof
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_feof(FILE* __stream) { return feof(__stream); }
+#undef feof
+inline _LIBCPP_INLINE_VISIBILITY int feof(FILE* __stream) { return __libcpp_feof(__stream); }
+#endif  // feof
+
+#ifdef ferror
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_ferror(FILE* __stream) { return ferror(__stream); }
+#undef ferror
+inline _LIBCPP_INLINE_VISIBILITY int ferror(FILE* __stream) { return __libcpp_ferror(__stream); }
+#endif  // ferror
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+using ::FILE;
+using ::fpos_t;
+using ::size_t;
+
+using ::fclose;
+using ::fflush;
+using ::setbuf;
+using ::setvbuf;
+using ::fprintf;
+using ::fscanf;
+using ::snprintf;
+using ::sprintf;
+using ::sscanf;
+#ifndef _LIBCPP_MSVCRT
+using ::vfprintf;
+using ::vfscanf;
+using ::vsscanf;
+#endif // _LIBCPP_MSVCRT
+using ::vsnprintf;
+using ::vsprintf;
+using ::fgetc;
+using ::fgets;
+using ::fputc;
+using ::fputs;
+using ::getc;
+using ::putc;
+using ::ungetc;
+using ::fread;
+using ::fwrite;
+using ::fgetpos;
+using ::fseek;
+using ::fsetpos;
+using ::ftell;
+using ::rewind;
+using ::clearerr;
+using ::feof;
+using ::ferror;
+using ::perror;
+
+#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+using ::fopen;
+using ::freopen;
+using ::remove;
+using ::rename;
+using ::tmpfile;
+using ::tmpnam;
+#endif
+
+#ifndef _LIBCPP_HAS_NO_STDIN
+using ::getchar;
+#if _LIBCPP_STD_VER <= 11
+using ::gets;
+#endif
+using ::scanf;
+using ::vscanf;
+#endif
+
+#ifndef _LIBCPP_HAS_NO_STDOUT
+using ::printf;
+using ::putchar;
+using ::puts;
+using ::vprintf;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CSTDIO

diff --git a/libcxx/include/cstdlib b/libcxx/include/cstdlib
new file mode 100644
index 0000000..55e15c8
--- /dev/null
+++ b/libcxx/include/cstdlib

@@ -0,0 +1,180 @@
+// -*- C++ -*-
+//===--------------------------- cstdlib ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CSTDLIB
+#define _LIBCPP_CSTDLIB
+
+/*
+    cstdlib synopsis
+
+Macros:
+
+    EXIT_FAILURE
+    EXIT_SUCCESS
+    MB_CUR_MAX
+    NULL
+    RAND_MAX
+
+namespace std
+{
+
+Types:
+
+    size_t
+    div_t
+    ldiv_t
+    lldiv_t                                                               // C99
+
+double    atof (const char* nptr);
+int       atoi (const char* nptr);
+long      atol (const char* nptr);
+long long atoll(const char* nptr);                                        // C99
+double             strtod  (const char* restrict nptr, char** restrict endptr);
+float              strtof  (const char* restrict nptr, char** restrict endptr); // C99
+long double        strtold (const char* restrict nptr, char** restrict endptr); // C99
+long               strtol  (const char* restrict nptr, char** restrict endptr, int base);
+long long          strtoll (const char* restrict nptr, char** restrict endptr, int base); // C99
+unsigned long      strtoul (const char* restrict nptr, char** restrict endptr, int base);
+unsigned long long strtoull(const char* restrict nptr, char** restrict endptr, int base); // C99
+int rand(void);
+void srand(unsigned int seed);
+void* calloc(size_t nmemb, size_t size);
+void free(void* ptr);
+void* malloc(size_t size);
+void* realloc(void* ptr, size_t size);
+void abort(void);
+int atexit(void (*func)(void));
+void exit(int status);
+void _Exit(int status);
+char* getenv(const char* name);
+int system(const char* string);
+void* bsearch(const void* key, const void* base, size_t nmemb, size_t size,
+              int (*compar)(const void *, const void *));
+void qsort(void* base, size_t nmemb, size_t size,
+           int (*compar)(const void *, const void *));
+int         abs(      int j);
+long        abs(     long j);
+long long   abs(long long j);                                             // C++0X
+long       labs(     long j);
+long long llabs(long long j);                                             // C99
+div_t     div(      int numer,       int denom);
+ldiv_t    div(     long numer,      long denom);
+lldiv_t   div(long long numer, long long denom);                          // C++0X
+ldiv_t   ldiv(     long numer,      long denom);
+lldiv_t lldiv(long long numer, long long denom);                          // C99
+int mblen(const char* s, size_t n);
+int mbtowc(wchar_t* restrict pwc, const char* restrict s, size_t n);
+int wctomb(char* s, wchar_t wchar);
+size_t mbstowcs(wchar_t* restrict pwcs, const char* restrict s, size_t n);
+size_t wcstombs(char* restrict s, const wchar_t* restrict pwcs, size_t n);
+int at_quick_exit(void (*func)(void))                                     // C++11
+void quick_exit(int status);                                              // C++11
+void *aligned_alloc(size_t alignment, size_t size);                       // C11
+
+}  // std
+
+*/
+
+#include <__config>
+#include <stdlib.h>
+#ifdef _LIBCPP_MSVCRT
+#include "support/win32/locale_win32.h"
+#endif // _LIBCPP_MSVCRT
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+using ::size_t;
+using ::div_t;
+using ::ldiv_t;
+#ifndef _LIBCPP_HAS_NO_LONG_LONG
+using ::lldiv_t;
+#endif // _LIBCPP_HAS_NO_LONG_LONG
+using ::atof;
+using ::atoi;
+using ::atol;
+#ifndef _LIBCPP_HAS_NO_LONG_LONG
+using ::atoll;
+#endif // _LIBCPP_HAS_NO_LONG_LONG
+using ::strtod;
+using ::strtof;
+using ::strtold;
+using ::strtol;
+#ifndef _LIBCPP_HAS_NO_LONG_LONG
+using ::strtoll;
+#endif // _LIBCPP_HAS_NO_LONG_LONG
+using ::strtoul;
+#ifndef _LIBCPP_HAS_NO_LONG_LONG
+using ::strtoull;
+#endif // _LIBCPP_HAS_NO_LONG_LONG
+using ::rand;
+using ::srand;
+using ::calloc;
+using ::free;
+using ::malloc;
+using ::realloc;
+using ::abort;
+using ::atexit;
+using ::exit;
+using ::_Exit;
+using ::getenv;
+using ::system;
+using ::bsearch;
+using ::qsort;
+#undef abs
+using ::abs;
+#undef labs
+using ::labs;
+#ifndef _LIBCPP_HAS_NO_LONG_LONG
+#undef llabs
+using ::llabs;
+#endif // _LIBCPP_HAS_NO_LONG_LONG
+#undef div
+using ::div;
+#undef ldiv
+using ::ldiv;
+#ifndef _LIBCPP_HAS_NO_LONG_LONG
+#undef lldiv
+using ::lldiv;
+#endif // _LIBCPP_HAS_NO_LONG_LONG
+#ifndef _LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS
+using ::mblen;
+using ::mbtowc;
+using ::wctomb;
+#endif
+using ::mbstowcs;
+using ::wcstombs;
+#ifdef _LIBCPP_HAS_QUICK_EXIT
+using ::at_quick_exit;
+using ::quick_exit;
+#endif
+#ifdef _LIBCPP_HAS_C11_FEATURES
+using ::aligned_alloc;
+#endif
+
+// MSVCRT already has the correct prototype in <stdlib.h> #ifdef __cplusplus
+#if !defined(_LIBCPP_MSVCRT) && !defined(__sun__) && !defined(_AIX)
+inline _LIBCPP_INLINE_VISIBILITY long      abs(     long __x) _NOEXCEPT {return  labs(__x);}
+#ifndef _LIBCPP_HAS_NO_LONG_LONG
+inline _LIBCPP_INLINE_VISIBILITY long long abs(long long __x) _NOEXCEPT {return llabs(__x);}
+#endif // _LIBCPP_HAS_NO_LONG_LONG
+
+inline _LIBCPP_INLINE_VISIBILITY  ldiv_t div(     long __x,      long __y) _NOEXCEPT {return  ldiv(__x, __y);}
+#ifndef _LIBCPP_HAS_NO_LONG_LONG
+inline _LIBCPP_INLINE_VISIBILITY lldiv_t div(long long __x, long long __y) _NOEXCEPT {return lldiv(__x, __y);}
+#endif // _LIBCPP_HAS_NO_LONG_LONG
+#endif // _LIBCPP_MSVCRT
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CSTDLIB

diff --git a/libcxx/include/cstring b/libcxx/include/cstring
new file mode 100644
index 0000000..d60b992
--- /dev/null
+++ b/libcxx/include/cstring

@@ -0,0 +1,114 @@
+// -*- C++ -*-
+//===--------------------------- cstring ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CSTRING
+#define _LIBCPP_CSTRING
+
+/*
+    cstring synopsis
+
+Macros:
+
+    NULL
+
+namespace std
+{
+
+Types:
+
+    size_t
+
+void* memcpy(void* restrict s1, const void* restrict s2, size_t n);
+void* memmove(void* s1, const void* s2, size_t n);
+char* strcpy (char* restrict s1, const char* restrict s2);
+char* strncpy(char* restrict s1, const char* restrict s2, size_t n);
+char* strcat (char* restrict s1, const char* restrict s2);
+char* strncat(char* restrict s1, const char* restrict s2, size_t n);
+int memcmp(const void* s1, const void* s2, size_t n);
+int strcmp (const char* s1, const char* s2);
+int strncmp(const char* s1, const char* s2, size_t n);
+int strcoll(const char* s1, const char* s2);
+size_t strxfrm(char* restrict s1, const char* restrict s2, size_t n);
+const void* memchr(const void* s, int c, size_t n);
+      void* memchr(      void* s, int c, size_t n);
+const char* strchr(const char* s, int c);
+      char* strchr(      char* s, int c);
+size_t strcspn(const char* s1, const char* s2);
+const char* strpbrk(const char* s1, const char* s2);
+      char* strpbrk(      char* s1, const char* s2);
+const char* strrchr(const char* s, int c);
+      char* strrchr(      char* s, int c);
+size_t strspn(const char* s1, const char* s2);
+const char* strstr(const char* s1, const char* s2);
+      char* strstr(      char* s1, const char* s2);
+char* strtok(char* restrict s1, const char* restrict s2);
+void* memset(void* s, int c, size_t n);
+char* strerror(int errnum);
+size_t strlen(const char* s);
+
+}  // std
+
+*/
+
+#include <__config>
+#include <string.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+using ::size_t;
+using ::memcpy;
+using ::memmove;
+using ::strcpy;
+using ::strncpy;
+using ::strcat;
+using ::strncat;
+using ::memcmp;
+using ::strcmp;
+using ::strncmp;
+using ::strcoll;
+using ::strxfrm;
+
+using ::memchr;
+
+using ::strchr;
+
+using ::strcspn;
+
+using ::strpbrk;
+
+using ::strrchr;
+
+using ::strspn;
+
+using ::strstr;
+
+// MSVCRT, GNU libc and its derivates already have the correct prototype in <string.h> #ifdef __cplusplus
+#if !defined(__GLIBC__) && !defined(_LIBCPP_MSVCRT) && !defined(__sun__) && !defined(_STRING_H_CPLUSPLUS_98_CONFORMANCE_)
+inline _LIBCPP_INLINE_VISIBILITY       char* strchr(      char* __s, int __c) {return ::strchr(__s, __c);}
+inline _LIBCPP_INLINE_VISIBILITY       char* strpbrk(      char* __s1, const char* __s2) {return ::strpbrk(__s1, __s2);}
+inline _LIBCPP_INLINE_VISIBILITY       char* strrchr(      char* __s, int __c) {return ::strrchr(__s, __c);}
+inline _LIBCPP_INLINE_VISIBILITY       void* memchr(      void* __s, int __c, size_t __n) {return ::memchr(__s, __c, __n);}
+inline _LIBCPP_INLINE_VISIBILITY       char* strstr(      char* __s1, const char* __s2) {return ::strstr(__s1, __s2);}
+#endif
+
+#ifndef _LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS
+using ::strtok;
+#endif
+using ::memset;
+using ::strerror;
+using ::strlen;
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CSTRING

diff --git a/libcxx/include/ctgmath b/libcxx/include/ctgmath
new file mode 100644
index 0000000..535eb7d
--- /dev/null
+++ b/libcxx/include/ctgmath

@@ -0,0 +1,29 @@
+// -*- C++ -*-
+//===-------------------------- ctgmath -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CTGMATH
+#define _LIBCPP_CTGMATH
+
+/*
+    ctgmath synopsis
+
+#include <ccomplex>
+#include <cmath>
+
+*/
+
+#include <ccomplex>
+#include <cmath>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#endif  // _LIBCPP_CTGMATH

diff --git a/libcxx/include/ctime b/libcxx/include/ctime
new file mode 100644
index 0000000..da9e329
--- /dev/null
+++ b/libcxx/include/ctime

@@ -0,0 +1,74 @@
+// -*- C++ -*-
+//===---------------------------- ctime -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CTIME
+#define _LIBCPP_CTIME
+
+/*
+    ctime synopsis
+
+Macros:
+
+    NULL
+    CLOCKS_PER_SEC
+
+namespace std
+{
+
+Types:
+
+    clock_t
+    size_t
+    time_t
+    tm
+
+clock_t clock();
+double difftime(time_t time1, time_t time0);
+time_t mktime(tm* timeptr);
+time_t time(time_t* timer);
+char* asctime(const tm* timeptr);
+char* ctime(const time_t* timer);
+tm*    gmtime(const time_t* timer);
+tm* localtime(const time_t* timer);
+size_t strftime(char* restrict s, size_t maxsize, const char* restrict format,
+                const tm* restrict timeptr);
+
+}  // std
+
+*/
+
+#include <__config>
+#include <time.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+using ::clock_t;
+using ::size_t;
+using ::time_t;
+using ::tm;
+using ::clock;
+using ::difftime;
+using ::mktime;
+using ::time;
+#ifndef _LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS
+using ::asctime;
+using ::ctime;
+using ::gmtime;
+using ::localtime;
+#endif
+using ::strftime;
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CTIME

diff --git a/libcxx/include/cwchar b/libcxx/include/cwchar
new file mode 100644
index 0000000..797a177
--- /dev/null
+++ b/libcxx/include/cwchar

@@ -0,0 +1,225 @@
+// -*- C++ -*-
+//===--------------------------- cwchar -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CWCHAR
+#define _LIBCPP_CWCHAR
+
+/*
+    cwchar synopsis
+
+Macros:
+
+    NULL
+    WCHAR_MAX
+    WCHAR_MIN
+    WEOF
+
+namespace std
+{
+
+Types:
+
+    mbstate_t
+    size_t
+    tm
+    wint_t
+
+int fwprintf(FILE* restrict stream, const wchar_t* restrict format, ...);
+int fwscanf(FILE* restrict stream, const wchar_t* restrict format, ...);
+int swprintf(wchar_t* restrict s, size_t n, const wchar_t* restrict format, ...);
+int swscanf(const wchar_t* restrict s, const wchar_t* restrict format, ...);
+int vfwprintf(FILE* restrict stream, const wchar_t* restrict format, va_list arg);
+int vfwscanf(FILE* restrict stream, const wchar_t* restrict format, va_list arg);  // C99
+int vswprintf(wchar_t* restrict s, size_t n, const wchar_t* restrict format, va_list arg);
+int vswscanf(const wchar_t* restrict s, const wchar_t* restrict format, va_list arg);  // C99
+int vwprintf(const wchar_t* restrict format, va_list arg);
+int vwscanf(const wchar_t* restrict format, va_list arg);  // C99
+int wprintf(const wchar_t* restrict format, ...);
+int wscanf(const wchar_t* restrict format, ...);
+wint_t fgetwc(FILE* stream);
+wchar_t* fgetws(wchar_t* restrict s, int n, FILE* restrict stream);
+wint_t fputwc(wchar_t c, FILE* stream);
+int fputws(const wchar_t* restrict s, FILE* restrict stream);
+int fwide(FILE* stream, int mode);
+wint_t getwc(FILE* stream);
+wint_t getwchar();
+wint_t putwc(wchar_t c, FILE* stream);
+wint_t putwchar(wchar_t c);
+wint_t ungetwc(wint_t c, FILE* stream);
+double wcstod(const wchar_t* restrict nptr, wchar_t** restrict endptr);
+float wcstof(const wchar_t* restrict nptr, wchar_t** restrict endptr);         // C99
+long double wcstold(const wchar_t* restrict nptr, wchar_t** restrict endptr);  // C99
+long wcstol(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);
+long long wcstoll(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);  // C99
+unsigned long wcstoul(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);
+unsigned long long wcstoull(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);  // C99
+wchar_t* wcscpy(wchar_t* restrict s1, const wchar_t* restrict s2);
+wchar_t* wcsncpy(wchar_t* restrict s1, const wchar_t* restrict s2, size_t n);
+wchar_t* wcscat(wchar_t* restrict s1, const wchar_t* restrict s2);
+wchar_t* wcsncat(wchar_t* restrict s1, const wchar_t* restrict s2, size_t n);
+int wcscmp(const wchar_t* s1, const wchar_t* s2);
+int wcscoll(const wchar_t* s1, const wchar_t* s2);
+int wcsncmp(const wchar_t* s1, const wchar_t* s2, size_t n);
+size_t wcsxfrm(wchar_t* restrict s1, const wchar_t* restrict s2, size_t n);
+const wchar_t* wcschr(const wchar_t* s, wchar_t c);
+      wchar_t* wcschr(      wchar_t* s, wchar_t c);
+size_t wcscspn(const wchar_t* s1, const wchar_t* s2);
+size_t wcslen(const wchar_t* s);
+const wchar_t* wcspbrk(const wchar_t* s1, const wchar_t* s2);
+      wchar_t* wcspbrk(      wchar_t* s1, const wchar_t* s2);
+const wchar_t* wcsrchr(const wchar_t* s, wchar_t c);
+      wchar_t* wcsrchr(      wchar_t* s, wchar_t c);
+size_t wcsspn(const wchar_t* s1, const wchar_t* s2);
+const wchar_t* wcsstr(const wchar_t* s1, const wchar_t* s2);
+      wchar_t* wcsstr(      wchar_t* s1, const wchar_t* s2);
+wchar_t* wcstok(wchar_t* restrict s1, const wchar_t* restrict s2, wchar_t** restrict ptr);
+const wchar_t* wmemchr(const wchar_t* s, wchar_t c, size_t n);
+      wchar_t* wmemchr(      wchar_t* s, wchar_t c, size_t n);
+int wmemcmp(wchar_t* restrict s1, const wchar_t* restrict s2, size_t n);
+wchar_t* wmemcpy(wchar_t* restrict s1, const wchar_t* restrict s2, size_t n);
+wchar_t* wmemmove(wchar_t* s1, const wchar_t* s2, size_t n);
+wchar_t* wmemset(wchar_t* s, wchar_t c, size_t n);
+size_t wcsftime(wchar_t* restrict s, size_t maxsize, const wchar_t* restrict format,
+                const tm* restrict timeptr);
+wint_t btowc(int c);
+int wctob(wint_t c);
+int mbsinit(const mbstate_t* ps);
+size_t mbrlen(const char* restrict s, size_t n, mbstate_t* restrict ps);
+size_t mbrtowc(wchar_t* restrict pwc, const char* restrict s, size_t n, mbstate_t* restrict ps);
+size_t wcrtomb(char* restrict s, wchar_t wc, mbstate_t* restrict ps);
+size_t mbsrtowcs(wchar_t* restrict dst, const char** restrict src, size_t len,
+                 mbstate_t* restrict ps);
+size_t wcsrtombs(char* restrict dst, const wchar_t** restrict src, size_t len,
+                 mbstate_t* restrict ps);
+
+}  // std
+
+*/
+
+#include <__config>
+#include <cwctype>
+#include <wchar.h>
+#if defined(_LIBCPP_MSVCRT) || defined(__MINGW32__)
+#include <support/win32/support.h> // pull in *swprintf defines
+#endif // _LIBCPP_MSVCRT
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+using ::mbstate_t;
+using ::size_t;
+using ::tm;
+using ::wint_t;
+using ::FILE;
+using ::fwprintf;
+using ::fwscanf;
+using ::swprintf;
+using ::vfwprintf;
+using ::vswprintf;
+#ifndef _LIBCPP_MSVCRT
+using ::swscanf;
+using ::vfwscanf;
+using ::vswscanf;
+#endif // _LIBCPP_MSVCRT
+using ::fgetwc;
+using ::fgetws;
+using ::fputwc;
+using ::fputws;
+using ::fwide;
+using ::getwc;
+using ::putwc;
+using ::ungetwc;
+using ::wcstod;
+#ifndef _LIBCPP_MSVCRT
+using ::wcstof;
+using ::wcstold;
+#endif // _LIBCPP_MSVCRT
+using ::wcstol;
+#ifndef _LIBCPP_HAS_NO_LONG_LONG
+using ::wcstoll;
+#endif // _LIBCPP_HAS_NO_LONG_LONG
+using ::wcstoul;
+#ifndef _LIBCPP_HAS_NO_LONG_LONG
+using ::wcstoull;
+#endif // _LIBCPP_HAS_NO_LONG_LONG
+using ::wcscpy;
+using ::wcsncpy;
+using ::wcscat;
+using ::wcsncat;
+using ::wcscmp;
+using ::wcscoll;
+using ::wcsncmp;
+using ::wcsxfrm;
+
+#if defined(_WCHAR_H_CPLUSPLUS_98_CONFORMANCE_)
+
+using ::wcschr;
+using ::wcspbrk;
+using ::wcsrchr;
+using ::wcsstr;
+using ::wmemchr;
+
+#else
+
+inline _LIBCPP_INLINE_VISIBILITY const wchar_t* wcschr(const wchar_t* __s, wchar_t __c) {return ::wcschr(__s, __c);}
+inline _LIBCPP_INLINE_VISIBILITY       wchar_t* wcschr(      wchar_t* __s, wchar_t __c) {return ::wcschr(__s, __c);}
+
+inline _LIBCPP_INLINE_VISIBILITY const wchar_t* wcspbrk(const wchar_t* __s1, const wchar_t* __s2) {return ::wcspbrk(__s1, __s2);}
+inline _LIBCPP_INLINE_VISIBILITY       wchar_t* wcspbrk(      wchar_t* __s1, const wchar_t* __s2) {return ::wcspbrk(__s1, __s2);}
+
+inline _LIBCPP_INLINE_VISIBILITY const wchar_t* wcsrchr(const wchar_t* __s, wchar_t __c) {return ::wcsrchr(__s, __c);}
+inline _LIBCPP_INLINE_VISIBILITY       wchar_t* wcsrchr(      wchar_t* __s, wchar_t __c) {return ::wcsrchr(__s, __c);}
+
+inline _LIBCPP_INLINE_VISIBILITY const wchar_t* wcsstr(const wchar_t* __s1, const wchar_t* __s2) {return ::wcsstr(__s1, __s2);}
+inline _LIBCPP_INLINE_VISIBILITY       wchar_t* wcsstr(      wchar_t* __s1, const wchar_t* __s2) {return ::wcsstr(__s1, __s2);}
+
+inline _LIBCPP_INLINE_VISIBILITY const wchar_t* wmemchr(const wchar_t* __s, wchar_t __c, size_t __n) {return ::wmemchr(__s, __c, __n);}
+inline _LIBCPP_INLINE_VISIBILITY       wchar_t* wmemchr(      wchar_t* __s, wchar_t __c, size_t __n) {return ::wmemchr(__s, __c, __n);}
+
+#endif
+
+using ::wcscspn;
+using ::wcslen;
+using ::wcsspn;
+using ::wcstok;
+using ::wmemcmp;
+using ::wmemcpy;
+using ::wmemmove;
+using ::wmemset;
+using ::wcsftime;
+using ::btowc;
+using ::wctob;
+using ::mbsinit;
+using ::mbrlen;
+using ::mbrtowc;
+using ::wcrtomb;
+using ::mbsrtowcs;
+using ::wcsrtombs;
+
+#ifndef _LIBCPP_HAS_NO_STDIN
+using ::getwchar;
+#ifndef _LIBCPP_MSVCRT
+using ::vwscanf;
+#endif // _LIBCPP_MSVCRT
+using ::wscanf;
+#endif
+
+#ifndef _LIBCPP_HAS_NO_STDOUT
+using ::putwchar;
+using ::vwprintf;
+using ::wprintf;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CWCHAR

diff --git a/libcxx/include/cwctype b/libcxx/include/cwctype
new file mode 100644
index 0000000..4f89b52
--- /dev/null
+++ b/libcxx/include/cwctype

@@ -0,0 +1,213 @@
+// -*- C++ -*-
+//===--------------------------- cwctype ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CWCTYPE
+#define _LIBCPP_CWCTYPE
+
+/*
+    cwctype synopsis
+
+Macros:
+
+    WEOF
+
+namespace std
+{
+
+Types:
+
+    wint_t
+    wctrans_t
+    wctype_t
+
+int iswalnum(wint_t wc);
+int iswalpha(wint_t wc);
+int iswblank(wint_t wc);  // C99
+int iswcntrl(wint_t wc);
+int iswdigit(wint_t wc);
+int iswgraph(wint_t wc);
+int iswlower(wint_t wc);
+int iswprint(wint_t wc);
+int iswpunct(wint_t wc);
+int iswspace(wint_t wc);
+int iswupper(wint_t wc);
+int iswxdigit(wint_t wc);
+int iswctype(wint_t wc, wctype_t desc);
+wctype_t wctype(const char* property);
+wint_t towlower(wint_t wc);
+wint_t towupper(wint_t wc);
+wint_t towctrans(wint_t wc, wctrans_t desc);
+wctrans_t wctrans(const char* property);
+
+}  // std
+
+*/
+
+#include <__config>
+#include <cctype>
+#include <wctype.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+using ::wint_t;
+using ::wctrans_t;
+using ::wctype_t;
+
+#ifdef iswalnum
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_iswalnum(wint_t __wc) {return iswalnum(__wc);}
+#undef iswalnum
+inline _LIBCPP_INLINE_VISIBILITY int iswalnum(wint_t __wc) {return __libcpp_iswalnum(__wc);}
+#else  // iswalnum
+using ::iswalnum;
+#endif
+
+#ifdef iswalpha
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_iswalpha(wint_t __wc) {return iswalpha(__wc);}
+#undef iswalpha
+inline _LIBCPP_INLINE_VISIBILITY int iswalpha(wint_t __wc) {return __libcpp_iswalpha(__wc);}
+#else  // iswalpha
+using ::iswalpha;
+#endif
+
+#ifdef iswblank
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_iswblank(wint_t __wc) {return iswblank(__wc);}
+#undef iswblank
+inline _LIBCPP_INLINE_VISIBILITY int iswblank(wint_t __wc) {return __libcpp_iswblank(__wc);}
+#else  // iswblank
+using ::iswblank;
+#endif
+
+#ifdef iswcntrl
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_iswcntrl(wint_t __wc) {return iswcntrl(__wc);}
+#undef iswcntrl
+inline _LIBCPP_INLINE_VISIBILITY int iswcntrl(wint_t __wc) {return __libcpp_iswcntrl(__wc);}
+#else  // iswcntrl
+using ::iswcntrl;
+#endif
+
+#ifdef iswdigit
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_iswdigit(wint_t __wc) {return iswdigit(__wc);}
+#undef iswdigit
+inline _LIBCPP_INLINE_VISIBILITY int iswdigit(wint_t __wc) {return __libcpp_iswdigit(__wc);}
+#else  // iswdigit
+using ::iswdigit;
+#endif
+
+#ifdef iswgraph
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_iswgraph(wint_t __wc) {return iswgraph(__wc);}
+#undef iswgraph
+inline _LIBCPP_INLINE_VISIBILITY int iswgraph(wint_t __wc) {return __libcpp_iswgraph(__wc);}
+#else  // iswgraph
+using ::iswgraph;
+#endif
+
+#ifdef iswlower
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_iswlower(wint_t __wc) {return iswlower(__wc);}
+#undef iswlower
+inline _LIBCPP_INLINE_VISIBILITY int iswlower(wint_t __wc) {return __libcpp_iswlower(__wc);}
+#else  // iswlower
+using ::iswlower;
+#endif
+
+#ifdef iswprint
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_iswprint(wint_t __wc) {return iswprint(__wc);}
+#undef iswprint
+inline _LIBCPP_INLINE_VISIBILITY int iswprint(wint_t __wc) {return __libcpp_iswprint(__wc);}
+#else  // iswprint
+using ::iswprint;
+#endif
+
+#ifdef iswpunct
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_iswpunct(wint_t __wc) {return iswpunct(__wc);}
+#undef iswpunct
+inline _LIBCPP_INLINE_VISIBILITY int iswpunct(wint_t __wc) {return __libcpp_iswpunct(__wc);}
+#else  // iswpunct
+using ::iswpunct;
+#endif
+
+#ifdef iswspace
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_iswspace(wint_t __wc) {return iswspace(__wc);}
+#undef iswspace
+inline _LIBCPP_INLINE_VISIBILITY int iswspace(wint_t __wc) {return __libcpp_iswspace(__wc);}
+#else  // iswspace
+using ::iswspace;
+#endif
+
+#ifdef iswupper
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_iswupper(wint_t __wc) {return iswupper(__wc);}
+#undef iswupper
+inline _LIBCPP_INLINE_VISIBILITY int iswupper(wint_t __wc) {return __libcpp_iswupper(__wc);}
+#else  // iswupper
+using ::iswupper;
+#endif
+
+#ifdef iswxdigit
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_iswxdigit(wint_t __wc) {return iswxdigit(__wc);}
+#undef iswxdigit
+inline _LIBCPP_INLINE_VISIBILITY int iswxdigit(wint_t __wc) {return __libcpp_iswxdigit(__wc);}
+#else  // iswxdigit
+using ::iswxdigit;
+#endif
+
+#ifdef iswctype
+inline _LIBCPP_INLINE_VISIBILITY int __libcpp_iswctype(wint_t __w, wctype_t __d) {return iswctype(__w, __d);}
+#undef iswctype
+inline _LIBCPP_INLINE_VISIBILITY int iswctype(wint_t __w, wctype_t __d) {return __libcpp_iswctype(__w, __d);}
+#else  // iswctype
+using ::iswctype;
+#endif
+
+#ifdef wctype
+inline _LIBCPP_INLINE_VISIBILITY wctype_t __libcpp_wctype(const char* __p) {return wctype(__p);}
+#undef wctype
+inline _LIBCPP_INLINE_VISIBILITY wctype_t wctype(const char* __p) {return __libcpp_wctype(__p);}
+#else  // wctype
+using ::wctype;
+#endif
+
+#ifdef towlower
+inline _LIBCPP_INLINE_VISIBILITY wint_t __libcpp_towlower(wint_t __wc) {return towlower(__wc);}
+#undef towlower
+inline _LIBCPP_INLINE_VISIBILITY wint_t towlower(wint_t __wc) {return __libcpp_towlower(__wc);}
+#else  // towlower
+using ::towlower;
+#endif
+
+#ifdef towupper
+inline _LIBCPP_INLINE_VISIBILITY wint_t __libcpp_towupper(wint_t __wc) {return towupper(__wc);}
+#undef towupper
+inline _LIBCPP_INLINE_VISIBILITY wint_t towupper(wint_t __wc) {return __libcpp_towupper(__wc);}
+#else  // towupper
+using ::towupper;
+#endif
+
+#ifdef towctrans
+inline _LIBCPP_INLINE_VISIBILITY wint_t __libcpp_towctrans(wint_t __wc, wctype_t __d) {return towctrans(__wc, __d);}
+#undef towctrans
+inline _LIBCPP_INLINE_VISIBILITY wint_t towctrans(wint_t __wc, wctype_t __d) {return __libcpp_towctrans(__wc, __d);}
+#else  // towctrans
+using ::towctrans;
+#endif
+
+#ifdef wctrans
+inline _LIBCPP_INLINE_VISIBILITY wctrans_t __libcpp_wctrans(const char* __p) {return wctrans(__p);}
+#undef wctrans
+inline _LIBCPP_INLINE_VISIBILITY wctrans_t wctrans(const char* __p) {return __libcpp_wctrans(__p);}
+#else  // wctrans
+using ::wctrans;
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_CWCTYPE

diff --git a/libcxx/include/deque b/libcxx/include/deque
new file mode 100644
index 0000000..87ff8bf
--- /dev/null
+++ b/libcxx/include/deque

@@ -0,0 +1,2860 @@
+// -*- C++ -*-
+//===---------------------------- deque -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_DEQUE
+#define _LIBCPP_DEQUE
+
+/*
+    deque synopsis
+
+namespace std
+{
+
+template <class T, class Allocator = allocator<T> >
+class deque
+{
+public:
+    // types:
+    typedef T value_type;
+    typedef Allocator allocator_type;
+
+    typedef typename allocator_type::reference       reference;
+    typedef typename allocator_type::const_reference const_reference;
+    typedef implementation-defined                   iterator;
+    typedef implementation-defined                   const_iterator;
+    typedef typename allocator_type::size_type       size_type;
+    typedef typename allocator_type::difference_type difference_type;
+
+    typedef typename allocator_type::pointer         pointer;
+    typedef typename allocator_type::const_pointer   const_pointer;
+    typedef std::reverse_iterator<iterator>          reverse_iterator;
+    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;
+
+    // construct/copy/destroy:
+    deque() noexcept(is_nothrow_default_constructible<allocator_type>::value);
+    explicit deque(const allocator_type& a);
+    explicit deque(size_type n);
+    explicit deque(size_type n, const allocator_type& a); // C++14
+    deque(size_type n, const value_type& v);
+    deque(size_type n, const value_type& v, const allocator_type& a);
+    template <class InputIterator>
+        deque(InputIterator f, InputIterator l);
+    template <class InputIterator>
+        deque(InputIterator f, InputIterator l, const allocator_type& a);
+    deque(const deque& c);
+    deque(deque&& c)
+        noexcept(is_nothrow_move_constructible<allocator_type>::value);
+    deque(initializer_list<value_type> il, const Allocator& a = allocator_type());
+    deque(const deque& c, const allocator_type& a);
+    deque(deque&& c, const allocator_type& a);
+    ~deque();
+
+    deque& operator=(const deque& c);
+    deque& operator=(deque&& c)
+        noexcept(
+             allocator_type::propagate_on_container_move_assignment::value &&
+             is_nothrow_move_assignable<allocator_type>::value);
+    deque& operator=(initializer_list<value_type> il);
+
+    template <class InputIterator>
+        void assign(InputIterator f, InputIterator l);
+    void assign(size_type n, const value_type& v);
+    void assign(initializer_list<value_type> il);
+
+    allocator_type get_allocator() const noexcept;
+
+    // iterators:
+
+    iterator       begin() noexcept;
+    const_iterator begin() const noexcept;
+    iterator       end() noexcept;
+    const_iterator end() const noexcept;
+
+    reverse_iterator       rbegin() noexcept;
+    const_reverse_iterator rbegin() const noexcept;
+    reverse_iterator       rend() noexcept;
+    const_reverse_iterator rend() const noexcept;
+
+    const_iterator         cbegin() const noexcept;
+    const_iterator         cend() const noexcept;
+    const_reverse_iterator crbegin() const noexcept;
+    const_reverse_iterator crend() const noexcept;
+
+    // capacity:
+    size_type size() const noexcept;
+    size_type max_size() const noexcept;
+    void resize(size_type n);
+    void resize(size_type n, const value_type& v);
+    void shrink_to_fit();
+    bool empty() const noexcept;
+
+    // element access:
+    reference operator[](size_type i);
+    const_reference operator[](size_type i) const;
+    reference at(size_type i);
+    const_reference at(size_type i) const;
+    reference front();
+    const_reference front() const;
+    reference back();
+    const_reference back() const;
+
+    // modifiers:
+    void push_front(const value_type& v);
+    void push_front(value_type&& v);
+    void push_back(const value_type& v);
+    void push_back(value_type&& v);
+    template <class... Args> void emplace_front(Args&&... args);
+    template <class... Args> void emplace_back(Args&&... args);
+    template <class... Args> iterator emplace(const_iterator p, Args&&... args);
+    iterator insert(const_iterator p, const value_type& v);
+    iterator insert(const_iterator p, value_type&& v);
+    iterator insert(const_iterator p, size_type n, const value_type& v);
+    template <class InputIterator>
+        iterator insert(const_iterator p, InputIterator f, InputIterator l);
+    iterator insert(const_iterator p, initializer_list<value_type> il);
+    void pop_front();
+    void pop_back();
+    iterator erase(const_iterator p);
+    iterator erase(const_iterator f, const_iterator l);
+    void swap(deque& c)
+        noexcept(allocator_traits<allocator_type>::is_always_equal::value);  // C++17
+    void clear() noexcept;
+};
+
+template <class T, class Allocator>
+    bool operator==(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
+template <class T, class Allocator>
+    bool operator< (const deque<T,Allocator>& x, const deque<T,Allocator>& y);
+template <class T, class Allocator>
+    bool operator!=(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
+template <class T, class Allocator>
+    bool operator> (const deque<T,Allocator>& x, const deque<T,Allocator>& y);
+template <class T, class Allocator>
+    bool operator>=(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
+template <class T, class Allocator>
+    bool operator<=(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
+
+// specialized algorithms:
+template <class T, class Allocator>
+    void swap(deque<T,Allocator>& x, deque<T,Allocator>& y)
+         noexcept(noexcept(x.swap(y)));
+
+}  // std
+
+*/
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#include <__config>
+#include <__split_buffer>
+#include <type_traits>
+#include <initializer_list>
+#include <iterator>
+#include <algorithm>
+#include <stdexcept>
+
+#include <__undef_min_max>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp, class _Allocator> class __deque_base;
+template <class _Tp, class _Allocator = allocator<_Tp> > class _LIBCPP_TYPE_VIS_ONLY deque;
+
+template <class _ValueType, class _Pointer, class _Reference, class _MapPointer,
+          class _DiffType, _DiffType _BlockSize>
+class _LIBCPP_TYPE_VIS_ONLY __deque_iterator;
+
+template <class _RAIter,
+          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+copy(_RAIter __f,
+     _RAIter __l,
+     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
+     typename enable_if<__is_random_access_iterator<_RAIter>::value>::type* = 0);
+
+template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+          class _OutputIterator>
+_OutputIterator
+copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+     _OutputIterator __r);
+
+template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
+
+template <class _RAIter,
+          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+copy_backward(_RAIter __f,
+              _RAIter __l,
+              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
+              typename enable_if<__is_random_access_iterator<_RAIter>::value>::type* = 0);
+
+template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+          class _OutputIterator>
+_OutputIterator
+copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+              _OutputIterator __r);
+
+template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
+
+template <class _RAIter,
+          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+move(_RAIter __f,
+     _RAIter __l,
+     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
+     typename enable_if<__is_random_access_iterator<_RAIter>::value>::type* = 0);
+
+template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+          class _OutputIterator>
+_OutputIterator
+move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+     _OutputIterator __r);
+
+template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
+
+template <class _RAIter,
+          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+move_backward(_RAIter __f,
+              _RAIter __l,
+              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
+              typename enable_if<__is_random_access_iterator<_RAIter>::value>::type* = 0);
+
+template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+          class _OutputIterator>
+_OutputIterator
+move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+              _OutputIterator __r);
+
+template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
+
+template <class _ValueType, class _Pointer, class _Reference, class _MapPointer,
+          class _DiffType, _DiffType _BlockSize>
+class _LIBCPP_TYPE_VIS_ONLY __deque_iterator
+{
+    typedef _MapPointer __map_iterator;
+public:
+    typedef _Pointer  pointer;
+    typedef _DiffType difference_type;
+private:
+    __map_iterator __m_iter_;
+    pointer        __ptr_;
+
+    static const difference_type __block_size = _BlockSize;
+public:
+    typedef _ValueType                  value_type;
+    typedef random_access_iterator_tag  iterator_category;
+    typedef _Reference                  reference;
+
+    _LIBCPP_INLINE_VISIBILITY __deque_iterator() _NOEXCEPT
+#if _LIBCPP_STD_VER > 11
+     : __m_iter_(nullptr), __ptr_(nullptr)
+#endif
+     {}
+
+    template <class _Pp, class _Rp, class _MP>
+    _LIBCPP_INLINE_VISIBILITY
+    __deque_iterator(const __deque_iterator<value_type, _Pp, _Rp, _MP, difference_type, __block_size>& __it,
+                typename enable_if<is_convertible<_Pp, pointer>::value>::type* = 0) _NOEXCEPT
+        : __m_iter_(__it.__m_iter_), __ptr_(__it.__ptr_) {}
+
+    _LIBCPP_INLINE_VISIBILITY reference operator*() const {return *__ptr_;}
+    _LIBCPP_INLINE_VISIBILITY pointer operator->() const {return __ptr_;}
+
+    _LIBCPP_INLINE_VISIBILITY __deque_iterator& operator++()
+    {
+        if (++__ptr_ - *__m_iter_ == __block_size)
+        {
+            ++__m_iter_;
+            __ptr_ = *__m_iter_;
+        }
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY __deque_iterator operator++(int)
+    {
+        __deque_iterator __tmp = *this;
+        ++(*this);
+        return __tmp;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY __deque_iterator& operator--()
+    {
+        if (__ptr_ == *__m_iter_)
+        {
+            --__m_iter_;
+            __ptr_ = *__m_iter_ + __block_size;
+        }
+        --__ptr_;
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY __deque_iterator operator--(int)
+    {
+        __deque_iterator __tmp = *this;
+        --(*this);
+        return __tmp;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY __deque_iterator& operator+=(difference_type __n)
+    {
+        if (__n != 0)
+        {
+            __n += __ptr_ - *__m_iter_;
+            if (__n > 0)
+            {
+                __m_iter_ += __n / __block_size;
+                __ptr_ = *__m_iter_ + __n % __block_size;
+            }
+            else // (__n < 0)
+            {
+                difference_type __z = __block_size - 1 - __n;
+                __m_iter_ -= __z / __block_size;
+                __ptr_ = *__m_iter_ + (__block_size - 1 - __z % __block_size);
+            }
+        }
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY __deque_iterator& operator-=(difference_type __n)
+    {
+        return *this += -__n;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY __deque_iterator operator+(difference_type __n) const
+    {
+        __deque_iterator __t(*this);
+        __t += __n;
+        return __t;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY __deque_iterator operator-(difference_type __n) const
+    {
+        __deque_iterator __t(*this);
+        __t -= __n;
+        return __t;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    friend __deque_iterator operator+(difference_type __n, const __deque_iterator& __it)
+        {return __it + __n;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    friend difference_type operator-(const __deque_iterator& __x, const __deque_iterator& __y)
+    {
+        if (__x != __y)
+            return (__x.__m_iter_ - __y.__m_iter_) * __block_size
+                 + (__x.__ptr_ - *__x.__m_iter_)
+                 - (__y.__ptr_ - *__y.__m_iter_);
+        return 0;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY reference operator[](difference_type __n) const
+        {return *(*this + __n);}
+
+    _LIBCPP_INLINE_VISIBILITY friend
+        bool operator==(const __deque_iterator& __x, const __deque_iterator& __y)
+        {return __x.__ptr_ == __y.__ptr_;}
+
+    _LIBCPP_INLINE_VISIBILITY friend
+        bool operator!=(const __deque_iterator& __x, const __deque_iterator& __y)
+        {return !(__x == __y);}
+
+    _LIBCPP_INLINE_VISIBILITY friend
+        bool operator<(const __deque_iterator& __x, const __deque_iterator& __y)
+        {return __x.__m_iter_ < __y.__m_iter_ ||
+               (__x.__m_iter_ == __y.__m_iter_ && __x.__ptr_ < __y.__ptr_);}
+
+    _LIBCPP_INLINE_VISIBILITY friend
+        bool operator>(const __deque_iterator& __x, const __deque_iterator& __y)
+        {return __y < __x;}
+
+    _LIBCPP_INLINE_VISIBILITY friend
+        bool operator<=(const __deque_iterator& __x, const __deque_iterator& __y)
+        {return !(__y < __x);}
+
+    _LIBCPP_INLINE_VISIBILITY friend
+        bool operator>=(const __deque_iterator& __x, const __deque_iterator& __y)
+        {return !(__x < __y);}
+
+private:
+    _LIBCPP_INLINE_VISIBILITY __deque_iterator(__map_iterator __m, pointer __p) _NOEXCEPT
+        : __m_iter_(__m), __ptr_(__p) {}
+
+    template <class _Tp, class _Ap> friend class __deque_base;
+    template <class _Tp, class _Ap> friend class _LIBCPP_TYPE_VIS_ONLY deque;
+    template <class _Vp, class _Pp, class _Rp, class _MP, class _Dp, _Dp>
+        friend class _LIBCPP_TYPE_VIS_ONLY __deque_iterator;
+
+    template <class _RAIter,
+              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+    friend
+    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+    copy(_RAIter __f,
+         _RAIter __l,
+         __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
+         typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*);
+
+    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+              class _OutputIterator>
+    friend
+    _OutputIterator
+    copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+         __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+         _OutputIterator __r);
+
+    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+    friend
+    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+    copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+         __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+         __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
+
+    template <class _RAIter,
+              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+    friend
+    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+    copy_backward(_RAIter __f,
+                  _RAIter __l,
+                  __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
+                  typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*);
+
+    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+              class _OutputIterator>
+    friend
+    _OutputIterator
+    copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+                  __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+                  _OutputIterator __r);
+
+    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+    friend
+    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+    copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+                  __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+                  __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
+
+    template <class _RAIter,
+              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+    friend
+    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+    move(_RAIter __f,
+         _RAIter __l,
+         __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
+         typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*);
+
+    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+              class _OutputIterator>
+    friend
+    _OutputIterator
+    move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+         __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+         _OutputIterator __r);
+
+    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+    friend
+    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+    move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+         __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+         __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
+
+    template <class _RAIter,
+              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+    friend
+    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+    move_backward(_RAIter __f,
+                  _RAIter __l,
+                  __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
+                  typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*);
+
+    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+              class _OutputIterator>
+    friend
+    _OutputIterator
+    move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+                  __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+                  _OutputIterator __r);
+
+    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+    friend
+    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+    move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+                  __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+                  __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
+};
+
+// copy
+
+template <class _RAIter,
+          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+copy(_RAIter __f,
+     _RAIter __l,
+     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
+     typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*)
+{
+    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::difference_type difference_type;
+    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::pointer pointer;
+    while (__f != __l)
+    {
+        pointer __rb = __r.__ptr_;
+        pointer __re = *__r.__m_iter_ + _B2;
+        difference_type __bs = __re - __rb;
+        difference_type __n = __l - __f;
+        _RAIter __m = __l;
+        if (__n > __bs)
+        {
+            __n = __bs;
+            __m = __f + __n;
+        }
+        _VSTD::copy(__f, __m, __rb);
+        __f = __m;
+        __r += __n;
+    }
+    return __r;
+}
+
+template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+          class _OutputIterator>
+_OutputIterator
+copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+     _OutputIterator __r)
+{
+    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
+    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
+    difference_type __n = __l - __f;
+    while (__n > 0)
+    {
+        pointer __fb = __f.__ptr_;
+        pointer __fe = *__f.__m_iter_ + _B1;
+        difference_type __bs = __fe - __fb;
+        if (__bs > __n)
+        {
+            __bs = __n;
+            __fe = __fb + __bs;
+        }
+        __r = _VSTD::copy(__fb, __fe, __r);
+        __n -= __bs;
+        __f += __bs;
+    }
+    return __r;
+}
+
+template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r)
+{
+    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
+    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
+    difference_type __n = __l - __f;
+    while (__n > 0)
+    {
+        pointer __fb = __f.__ptr_;
+        pointer __fe = *__f.__m_iter_ + _B1;
+        difference_type __bs = __fe - __fb;
+        if (__bs > __n)
+        {
+            __bs = __n;
+            __fe = __fb + __bs;
+        }
+        __r = _VSTD::copy(__fb, __fe, __r);
+        __n -= __bs;
+        __f += __bs;
+    }
+    return __r;
+}
+
+// copy_backward
+
+template <class _RAIter,
+          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+copy_backward(_RAIter __f,
+              _RAIter __l,
+              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
+              typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*)
+{
+    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::difference_type difference_type;
+    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::pointer pointer;
+    while (__f != __l)
+    {
+        __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __rp = _VSTD::prev(__r);
+        pointer __rb = *__rp.__m_iter_;
+        pointer __re = __rp.__ptr_ + 1;
+        difference_type __bs = __re - __rb;
+        difference_type __n = __l - __f;
+        _RAIter __m = __f;
+        if (__n > __bs)
+        {
+            __n = __bs;
+            __m = __l - __n;
+        }
+        _VSTD::copy_backward(__m, __l, __re);
+        __l = __m;
+        __r -= __n;
+    }
+    return __r;
+}
+
+template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+          class _OutputIterator>
+_OutputIterator
+copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+              _OutputIterator __r)
+{
+    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
+    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
+    difference_type __n = __l - __f;
+    while (__n > 0)
+    {
+        --__l;
+        pointer __lb = *__l.__m_iter_;
+        pointer __le = __l.__ptr_ + 1;
+        difference_type __bs = __le - __lb;
+        if (__bs > __n)
+        {
+            __bs = __n;
+            __lb = __le - __bs;
+        }
+        __r = _VSTD::copy_backward(__lb, __le, __r);
+        __n -= __bs;
+        __l -= __bs - 1;
+    }
+    return __r;
+}
+
+template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r)
+{
+    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
+    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
+    difference_type __n = __l - __f;
+    while (__n > 0)
+    {
+        --__l;
+        pointer __lb = *__l.__m_iter_;
+        pointer __le = __l.__ptr_ + 1;
+        difference_type __bs = __le - __lb;
+        if (__bs > __n)
+        {
+            __bs = __n;
+            __lb = __le - __bs;
+        }
+        __r = _VSTD::copy_backward(__lb, __le, __r);
+        __n -= __bs;
+        __l -= __bs - 1;
+    }
+    return __r;
+}
+
+// move
+
+template <class _RAIter,
+          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+move(_RAIter __f,
+     _RAIter __l,
+     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
+     typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*)
+{
+    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::difference_type difference_type;
+    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::pointer pointer;
+    while (__f != __l)
+    {
+        pointer __rb = __r.__ptr_;
+        pointer __re = *__r.__m_iter_ + _B2;
+        difference_type __bs = __re - __rb;
+        difference_type __n = __l - __f;
+        _RAIter __m = __l;
+        if (__n > __bs)
+        {
+            __n = __bs;
+            __m = __f + __n;
+        }
+        _VSTD::move(__f, __m, __rb);
+        __f = __m;
+        __r += __n;
+    }
+    return __r;
+}
+
+template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+          class _OutputIterator>
+_OutputIterator
+move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+     _OutputIterator __r)
+{
+    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
+    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
+    difference_type __n = __l - __f;
+    while (__n > 0)
+    {
+        pointer __fb = __f.__ptr_;
+        pointer __fe = *__f.__m_iter_ + _B1;
+        difference_type __bs = __fe - __fb;
+        if (__bs > __n)
+        {
+            __bs = __n;
+            __fe = __fb + __bs;
+        }
+        __r = _VSTD::move(__fb, __fe, __r);
+        __n -= __bs;
+        __f += __bs;
+    }
+    return __r;
+}
+
+template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r)
+{
+    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
+    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
+    difference_type __n = __l - __f;
+    while (__n > 0)
+    {
+        pointer __fb = __f.__ptr_;
+        pointer __fe = *__f.__m_iter_ + _B1;
+        difference_type __bs = __fe - __fb;
+        if (__bs > __n)
+        {
+            __bs = __n;
+            __fe = __fb + __bs;
+        }
+        __r = _VSTD::move(__fb, __fe, __r);
+        __n -= __bs;
+        __f += __bs;
+    }
+    return __r;
+}
+
+// move_backward
+
+template <class _RAIter,
+          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+move_backward(_RAIter __f,
+              _RAIter __l,
+              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
+              typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*)
+{
+    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::difference_type difference_type;
+    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::pointer pointer;
+    while (__f != __l)
+    {
+        __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __rp = _VSTD::prev(__r);
+        pointer __rb = *__rp.__m_iter_;
+        pointer __re = __rp.__ptr_ + 1;
+        difference_type __bs = __re - __rb;
+        difference_type __n = __l - __f;
+        _RAIter __m = __f;
+        if (__n > __bs)
+        {
+            __n = __bs;
+            __m = __l - __n;
+        }
+        _VSTD::move_backward(__m, __l, __re);
+        __l = __m;
+        __r -= __n;
+    }
+    return __r;
+}
+
+template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+          class _OutputIterator>
+_OutputIterator
+move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+              _OutputIterator __r)
+{
+    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
+    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
+    difference_type __n = __l - __f;
+    while (__n > 0)
+    {
+        --__l;
+        pointer __lb = *__l.__m_iter_;
+        pointer __le = __l.__ptr_ + 1;
+        difference_type __bs = __le - __lb;
+        if (__bs > __n)
+        {
+            __bs = __n;
+            __lb = __le - __bs;
+        }
+        __r = _VSTD::move_backward(__lb, __le, __r);
+        __n -= __bs;
+        __l -= __bs - 1;
+    }
+    return __r;
+}
+
+template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
+          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
+__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
+move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
+              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
+              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r)
+{
+    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
+    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
+    difference_type __n = __l - __f;
+    while (__n > 0)
+    {
+        --__l;
+        pointer __lb = *__l.__m_iter_;
+        pointer __le = __l.__ptr_ + 1;
+        difference_type __bs = __le - __lb;
+        if (__bs > __n)
+        {
+            __bs = __n;
+            __lb = __le - __bs;
+        }
+        __r = _VSTD::move_backward(__lb, __le, __r);
+        __n -= __bs;
+        __l -= __bs - 1;
+    }
+    return __r;
+}
+
+template <bool>
+class __deque_base_common
+{
+protected:
+    void __throw_length_error() const;
+    void __throw_out_of_range() const;
+};
+
+template <bool __b>
+void
+__deque_base_common<__b>::__throw_length_error() const
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    throw length_error("deque");
+#endif
+}
+
+template <bool __b>
+void
+__deque_base_common<__b>::__throw_out_of_range() const
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    throw out_of_range("deque");
+#endif
+}
+
+template <class _Tp, class _Allocator>
+class __deque_base
+    : protected __deque_base_common<true>
+{
+    __deque_base(const __deque_base& __c);
+    __deque_base& operator=(const __deque_base& __c);
+protected:
+    typedef _Tp                                      value_type;
+    typedef _Allocator                               allocator_type;
+    typedef allocator_traits<allocator_type>         __alloc_traits;
+    typedef value_type&                              reference;
+    typedef const value_type&                        const_reference;
+    typedef typename __alloc_traits::size_type       size_type;
+    typedef typename __alloc_traits::difference_type difference_type;
+    typedef typename __alloc_traits::pointer         pointer;
+    typedef typename __alloc_traits::const_pointer   const_pointer;
+
+    static const difference_type __block_size = sizeof(value_type) < 256 ? 4096 / sizeof(value_type) : 16;
+
+    typedef typename __rebind_alloc_helper<__alloc_traits, pointer>::type __pointer_allocator;
+    typedef allocator_traits<__pointer_allocator>        __map_traits;
+    typedef typename __map_traits::pointer               __map_pointer;
+    typedef typename __rebind_alloc_helper<__alloc_traits, const_pointer>::type __const_pointer_allocator;
+    typedef typename allocator_traits<__const_pointer_allocator>::const_pointer __map_const_pointer;
+    typedef __split_buffer<pointer, __pointer_allocator> __map;
+
+    typedef __deque_iterator<value_type, pointer, reference, __map_pointer,
+                             difference_type, __block_size>    iterator;
+    typedef __deque_iterator<value_type, const_pointer, const_reference, __map_const_pointer,
+                             difference_type, __block_size>    const_iterator;
+
+    __map __map_;
+    size_type __start_;
+    __compressed_pair<size_type, allocator_type> __size_;
+
+    iterator       begin() _NOEXCEPT;
+    const_iterator begin() const _NOEXCEPT;
+    iterator       end() _NOEXCEPT;
+    const_iterator end() const _NOEXCEPT;
+
+    _LIBCPP_INLINE_VISIBILITY size_type&            size()          {return __size_.first();}
+    _LIBCPP_INLINE_VISIBILITY
+    const size_type& size() const _NOEXCEPT {return __size_.first();}
+    _LIBCPP_INLINE_VISIBILITY allocator_type&       __alloc()       {return __size_.second();}
+    _LIBCPP_INLINE_VISIBILITY
+    const allocator_type& __alloc() const _NOEXCEPT {return __size_.second();}
+
+    __deque_base()
+        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value);
+    explicit __deque_base(const allocator_type& __a);
+public:
+    ~__deque_base();
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    __deque_base(__deque_base&& __c)
+        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
+    __deque_base(__deque_base&& __c, const allocator_type& __a);
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    void swap(__deque_base& __c)
+#if _LIBCPP_STD_VER >= 14
+        _NOEXCEPT;
+#else
+        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || 
+                    __is_nothrow_swappable<allocator_type>::value);
+#endif
+protected:
+    void clear() _NOEXCEPT;
+
+    bool __invariants() const;
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign(__deque_base& __c)
+        _NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
+                   is_nothrow_move_assignable<allocator_type>::value)
+    {
+        __map_ = _VSTD::move(__c.__map_);
+        __start_ = __c.__start_;
+        size() = __c.size();
+        __move_assign_alloc(__c);
+        __c.__start_ = __c.size() = 0;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__deque_base& __c)
+        _NOEXCEPT_(!__alloc_traits::propagate_on_container_move_assignment::value ||
+                   is_nothrow_move_assignable<allocator_type>::value)
+        {__move_assign_alloc(__c, integral_constant<bool,
+                      __alloc_traits::propagate_on_container_move_assignment::value>());}
+
+private:
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__deque_base& __c, true_type)
+        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
+        {
+            __alloc() = _VSTD::move(__c.__alloc());
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__deque_base&, false_type) _NOEXCEPT
+        {}
+};
+
+template <class _Tp, class _Allocator>
+bool
+__deque_base<_Tp, _Allocator>::__invariants() const
+{
+    if (!__map_.__invariants())
+        return false;
+    if (__map_.size() >= size_type(-1) / __block_size)
+        return false;
+    for (typename __map::const_iterator __i = __map_.begin(), __e = __map_.end();
+         __i != __e; ++__i)
+        if (*__i == nullptr)
+            return false;
+    if (__map_.size() != 0)
+    {
+        if (size() >= __map_.size() * __block_size)
+            return false;
+        if (__start_ >= __map_.size() * __block_size - size())
+            return false;
+    }
+    else
+    {
+        if (size() != 0)
+            return false;
+        if (__start_ != 0)
+            return false;
+    }
+    return true;
+}
+
+template <class _Tp, class _Allocator>
+typename __deque_base<_Tp, _Allocator>::iterator
+__deque_base<_Tp, _Allocator>::begin() _NOEXCEPT
+{
+    __map_pointer __mp = __map_.begin() + __start_ / __block_size;
+    return iterator(__mp, __map_.empty() ? 0 : *__mp + __start_ % __block_size);
+}
+
+template <class _Tp, class _Allocator>
+typename __deque_base<_Tp, _Allocator>::const_iterator
+__deque_base<_Tp, _Allocator>::begin() const _NOEXCEPT
+{
+    __map_const_pointer __mp = static_cast<__map_const_pointer>(__map_.begin() + __start_ / __block_size);
+    return const_iterator(__mp, __map_.empty() ? 0 : *__mp + __start_ % __block_size);
+}
+
+template <class _Tp, class _Allocator>
+typename __deque_base<_Tp, _Allocator>::iterator
+__deque_base<_Tp, _Allocator>::end() _NOEXCEPT
+{
+    size_type __p = size() + __start_;
+    __map_pointer __mp = __map_.begin() + __p / __block_size;
+    return iterator(__mp, __map_.empty() ? 0 : *__mp + __p % __block_size);
+}
+
+template <class _Tp, class _Allocator>
+typename __deque_base<_Tp, _Allocator>::const_iterator
+__deque_base<_Tp, _Allocator>::end() const _NOEXCEPT
+{
+    size_type __p = size() + __start_;
+    __map_const_pointer __mp = static_cast<__map_const_pointer>(__map_.begin() + __p / __block_size);
+    return const_iterator(__mp, __map_.empty() ? 0 : *__mp + __p % __block_size);
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+__deque_base<_Tp, _Allocator>::__deque_base()
+    _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
+    : __start_(0), __size_(0) {}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+__deque_base<_Tp, _Allocator>::__deque_base(const allocator_type& __a)
+    : __map_(__pointer_allocator(__a)), __start_(0), __size_(0, __a) {}
+
+template <class _Tp, class _Allocator>
+__deque_base<_Tp, _Allocator>::~__deque_base()
+{
+    clear();
+    typename __map::iterator __i = __map_.begin();
+    typename __map::iterator __e = __map_.end();
+    for (; __i != __e; ++__i)
+        __alloc_traits::deallocate(__alloc(), *__i, __block_size);
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Allocator>
+__deque_base<_Tp, _Allocator>::__deque_base(__deque_base&& __c)
+    _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
+    : __map_(_VSTD::move(__c.__map_)),
+      __start_(_VSTD::move(__c.__start_)),
+      __size_(_VSTD::move(__c.__size_))
+{
+    __c.__start_ = 0;
+    __c.size() = 0;
+}
+
+template <class _Tp, class _Allocator>
+__deque_base<_Tp, _Allocator>::__deque_base(__deque_base&& __c, const allocator_type& __a)
+    : __map_(_VSTD::move(__c.__map_), __pointer_allocator(__a)),
+      __start_(_VSTD::move(__c.__start_)),
+      __size_(_VSTD::move(__c.size()), __a)
+{
+    if (__a == __c.__alloc())
+    {
+        __c.__start_ = 0;
+        __c.size() = 0;
+    }
+    else
+    {
+        __map_.clear();
+        __start_ = 0;
+        size() = 0;
+    }
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Allocator>
+void
+__deque_base<_Tp, _Allocator>::swap(__deque_base& __c)
+#if _LIBCPP_STD_VER >= 14
+        _NOEXCEPT
+#else
+        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || 
+                    __is_nothrow_swappable<allocator_type>::value)
+#endif
+{
+    __map_.swap(__c.__map_);
+    _VSTD::swap(__start_, __c.__start_);
+    _VSTD::swap(size(), __c.size());
+    __swap_allocator(__alloc(), __c.__alloc());
+}
+
+template <class _Tp, class _Allocator>
+void
+__deque_base<_Tp, _Allocator>::clear() _NOEXCEPT
+{
+    allocator_type& __a = __alloc();
+    for (iterator __i = begin(), __e = end(); __i != __e; ++__i)
+        __alloc_traits::destroy(__a, _VSTD::addressof(*__i));
+    size() = 0;
+    while (__map_.size() > 2)
+    {
+        __alloc_traits::deallocate(__a, __map_.front(), __block_size);
+        __map_.pop_front();
+    }
+    switch (__map_.size())
+    {
+    case 1:
+        __start_ = __block_size / 2;
+        break;
+    case 2:
+        __start_ = __block_size;
+        break;
+    }
+}
+
+template <class _Tp, class _Allocator /*= allocator<_Tp>*/>
+class _LIBCPP_TYPE_VIS_ONLY deque
+    : private __deque_base<_Tp, _Allocator>
+{
+public:
+    // types:
+
+    typedef _Tp value_type;
+    typedef _Allocator allocator_type;
+
+    typedef __deque_base<value_type, allocator_type> __base;
+
+    typedef typename __base::__alloc_traits        __alloc_traits;
+    typedef typename __base::reference             reference;
+    typedef typename __base::const_reference       const_reference;
+    typedef typename __base::iterator              iterator;
+    typedef typename __base::const_iterator        const_iterator;
+    typedef typename __base::size_type             size_type;
+    typedef typename __base::difference_type       difference_type;
+
+    typedef typename __base::pointer               pointer;
+    typedef typename __base::const_pointer         const_pointer;
+    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
+    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
+
+    // construct/copy/destroy:
+    _LIBCPP_INLINE_VISIBILITY
+    deque()
+        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
+        {}
+    _LIBCPP_INLINE_VISIBILITY explicit deque(const allocator_type& __a) : __base(__a) {}
+    explicit deque(size_type __n);
+#if _LIBCPP_STD_VER > 11
+    explicit deque(size_type __n, const _Allocator& __a);
+#endif
+    deque(size_type __n, const value_type& __v);
+    deque(size_type __n, const value_type& __v, const allocator_type& __a);
+    template <class _InputIter>
+        deque(_InputIter __f, _InputIter __l,
+              typename enable_if<__is_input_iterator<_InputIter>::value>::type* = 0);
+    template <class _InputIter>
+        deque(_InputIter __f, _InputIter __l, const allocator_type& __a,
+              typename enable_if<__is_input_iterator<_InputIter>::value>::type* = 0);
+    deque(const deque& __c);
+    deque(const deque& __c, const allocator_type& __a);
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+    deque(initializer_list<value_type> __il);
+    deque(initializer_list<value_type> __il, const allocator_type& __a);
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+    deque& operator=(const deque& __c);
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+    _LIBCPP_INLINE_VISIBILITY
+    deque& operator=(initializer_list<value_type> __il) {assign(__il); return *this;}
+#endif   // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    deque(deque&& __c) _NOEXCEPT_(is_nothrow_move_constructible<__base>::value);
+    deque(deque&& __c, const allocator_type& __a);
+    deque& operator=(deque&& __c)
+        _NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
+                   is_nothrow_move_assignable<allocator_type>::value);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    template <class _InputIter>
+        void assign(_InputIter __f, _InputIter __l,
+                    typename enable_if<__is_input_iterator<_InputIter>::value &&
+                                      !__is_random_access_iterator<_InputIter>::value>::type* = 0);
+    template <class _RAIter>
+        void assign(_RAIter __f, _RAIter __l,
+                    typename enable_if<__is_random_access_iterator<_RAIter>::value>::type* = 0);
+    void assign(size_type __n, const value_type& __v);
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+    _LIBCPP_INLINE_VISIBILITY
+    void assign(initializer_list<value_type> __il) {assign(__il.begin(), __il.end());}
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+    allocator_type get_allocator() const _NOEXCEPT;
+
+    // iterators:
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       begin() _NOEXCEPT       {return __base::begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator begin() const _NOEXCEPT {return __base::begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       end() _NOEXCEPT         {return __base::end();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator end()   const _NOEXCEPT {return __base::end();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    reverse_iterator       rbegin() _NOEXCEPT
+        {return       reverse_iterator(__base::end());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator rbegin() const _NOEXCEPT
+        {return const_reverse_iterator(__base::end());}
+    _LIBCPP_INLINE_VISIBILITY
+    reverse_iterator       rend() _NOEXCEPT
+        {return       reverse_iterator(__base::begin());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator rend()   const _NOEXCEPT
+        {return const_reverse_iterator(__base::begin());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator         cbegin()  const _NOEXCEPT
+        {return __base::begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator         cend()    const _NOEXCEPT
+        {return __base::end();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator crbegin() const _NOEXCEPT
+        {return const_reverse_iterator(__base::end());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator crend()   const _NOEXCEPT
+        {return const_reverse_iterator(__base::begin());}
+
+    // capacity:
+    _LIBCPP_INLINE_VISIBILITY
+    size_type size() const _NOEXCEPT {return __base::size();}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type max_size() const _NOEXCEPT
+        {return __alloc_traits::max_size(__base::__alloc());}
+    void resize(size_type __n);
+    void resize(size_type __n, const value_type& __v);
+    void shrink_to_fit() _NOEXCEPT;
+    _LIBCPP_INLINE_VISIBILITY
+    bool empty() const _NOEXCEPT {return __base::size() == 0;}
+
+    // element access:
+    reference operator[](size_type __i);
+    const_reference operator[](size_type __i) const;
+    reference at(size_type __i);
+    const_reference at(size_type __i) const;
+    reference front();
+    const_reference front() const;
+    reference back();
+    const_reference back() const;
+
+    // 23.2.2.3 modifiers:
+    void push_front(const value_type& __v);
+    void push_back(const value_type& __v);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    template <class... _Args> void emplace_front(_Args&&... __args);
+    template <class... _Args> void emplace_back(_Args&&... __args);
+    template <class... _Args> iterator emplace(const_iterator __p, _Args&&... __args);
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+    void push_front(value_type&& __v);
+    void push_back(value_type&& __v);
+    iterator insert(const_iterator __p, value_type&& __v);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    iterator insert(const_iterator __p, const value_type& __v);
+    iterator insert(const_iterator __p, size_type __n, const value_type& __v);
+    template <class _InputIter>
+        iterator insert(const_iterator __p, _InputIter __f, _InputIter __l,
+                         typename enable_if<__is_input_iterator<_InputIter>::value
+                                         &&!__is_forward_iterator<_InputIter>::value>::type* = 0);
+    template <class _ForwardIterator>
+        iterator insert(const_iterator __p, _ForwardIterator __f, _ForwardIterator __l,
+                               typename enable_if<__is_forward_iterator<_ForwardIterator>::value
+                                         &&!__is_bidirectional_iterator<_ForwardIterator>::value>::type* = 0);
+    template <class _BiIter>
+        iterator insert(const_iterator __p, _BiIter __f, _BiIter __l,
+                         typename enable_if<__is_bidirectional_iterator<_BiIter>::value>::type* = 0);
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+    _LIBCPP_INLINE_VISIBILITY
+    iterator insert(const_iterator __p, initializer_list<value_type> __il)
+        {return insert(__p, __il.begin(), __il.end());}
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+    void pop_front();
+    void pop_back();
+    iterator erase(const_iterator __p);
+    iterator erase(const_iterator __f, const_iterator __l);
+
+    void swap(deque& __c)
+#if _LIBCPP_STD_VER >= 14
+        _NOEXCEPT;
+#else
+        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
+                   __is_nothrow_swappable<allocator_type>::value);
+#endif
+    void clear() _NOEXCEPT;
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool __invariants() const {return __base::__invariants();}
+private:
+    typedef typename __base::__map_const_pointer __map_const_pointer;
+
+    _LIBCPP_INLINE_VISIBILITY
+    static size_type __recommend_blocks(size_type __n)
+    {
+        return __n / __base::__block_size + (__n % __base::__block_size != 0);
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    size_type __capacity() const
+    {
+        return __base::__map_.size() == 0 ? 0 : __base::__map_.size() * __base::__block_size - 1;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    size_type __front_spare() const
+    {
+        return __base::__start_;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    size_type __back_spare() const
+    {
+        return __capacity() - (__base::__start_ + __base::size());
+    }
+
+    template <class _InpIter>
+        void __append(_InpIter __f, _InpIter __l,
+                 typename enable_if<__is_input_iterator<_InpIter>::value &&
+                                   !__is_forward_iterator<_InpIter>::value>::type* = 0);
+    template <class _ForIter>
+        void __append(_ForIter __f, _ForIter __l,
+                      typename enable_if<__is_forward_iterator<_ForIter>::value>::type* = 0);
+    void __append(size_type __n);
+    void __append(size_type __n, const value_type& __v);
+    void __erase_to_end(const_iterator __f);
+    void __add_front_capacity();
+    void __add_front_capacity(size_type __n);
+    void __add_back_capacity();
+    void __add_back_capacity(size_type __n);
+    iterator __move_and_check(iterator __f, iterator __l, iterator __r,
+                              const_pointer& __vt);
+    iterator __move_backward_and_check(iterator __f, iterator __l, iterator __r,
+                                       const_pointer& __vt);
+    void __move_construct_and_check(iterator __f, iterator __l,
+                                    iterator __r, const_pointer& __vt);
+    void __move_construct_backward_and_check(iterator __f, iterator __l,
+                                             iterator __r, const_pointer& __vt);
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __copy_assign_alloc(const deque& __c)
+        {__copy_assign_alloc(__c, integral_constant<bool,
+                      __alloc_traits::propagate_on_container_copy_assignment::value>());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __copy_assign_alloc(const deque& __c, true_type)
+        {
+            if (__base::__alloc() != __c.__alloc())
+            {
+                clear();
+                shrink_to_fit();
+            }
+            __base::__alloc() = __c.__alloc();
+            __base::__map_.__alloc() = __c.__map_.__alloc();
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __copy_assign_alloc(const deque&, false_type)
+        {}
+
+    void __move_assign(deque& __c, true_type)
+        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value);
+    void __move_assign(deque& __c, false_type);
+};
+
+template <class _Tp, class _Allocator>
+deque<_Tp, _Allocator>::deque(size_type __n)
+{
+    if (__n > 0)
+        __append(__n);
+}
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp, class _Allocator>
+deque<_Tp, _Allocator>::deque(size_type __n, const _Allocator& __a)
+    : __base(__a)
+{
+    if (__n > 0)
+        __append(__n);
+}
+#endif
+
+template <class _Tp, class _Allocator>
+deque<_Tp, _Allocator>::deque(size_type __n, const value_type& __v)
+{
+    if (__n > 0)
+        __append(__n, __v);
+}
+
+template <class _Tp, class _Allocator>
+deque<_Tp, _Allocator>::deque(size_type __n, const value_type& __v, const allocator_type& __a)
+    : __base(__a)
+{
+    if (__n > 0)
+        __append(__n, __v);
+}
+
+template <class _Tp, class _Allocator>
+template <class _InputIter>
+deque<_Tp, _Allocator>::deque(_InputIter __f, _InputIter __l,
+              typename enable_if<__is_input_iterator<_InputIter>::value>::type*)
+{
+    __append(__f, __l);
+}
+
+template <class _Tp, class _Allocator>
+template <class _InputIter>
+deque<_Tp, _Allocator>::deque(_InputIter __f, _InputIter __l, const allocator_type& __a,
+              typename enable_if<__is_input_iterator<_InputIter>::value>::type*)
+    : __base(__a)
+{
+    __append(__f, __l);
+}
+
+template <class _Tp, class _Allocator>
+deque<_Tp, _Allocator>::deque(const deque& __c)
+    : __base(__alloc_traits::select_on_container_copy_construction(__c.__alloc()))
+{
+    __append(__c.begin(), __c.end());
+}
+
+template <class _Tp, class _Allocator>
+deque<_Tp, _Allocator>::deque(const deque& __c, const allocator_type& __a)
+    : __base(__a)
+{
+    __append(__c.begin(), __c.end());
+}
+
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+template <class _Tp, class _Allocator>
+deque<_Tp, _Allocator>::deque(initializer_list<value_type> __il)
+{
+    __append(__il.begin(), __il.end());
+}
+
+template <class _Tp, class _Allocator>
+deque<_Tp, _Allocator>::deque(initializer_list<value_type> __il, const allocator_type& __a)
+    : __base(__a)
+{
+    __append(__il.begin(), __il.end());
+}
+
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+template <class _Tp, class _Allocator>
+deque<_Tp, _Allocator>&
+deque<_Tp, _Allocator>::operator=(const deque& __c)
+{
+    if (this != &__c)
+    {
+        __copy_assign_alloc(__c);
+        assign(__c.begin(), __c.end());
+    }
+    return *this;
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+deque<_Tp, _Allocator>::deque(deque&& __c)
+    _NOEXCEPT_(is_nothrow_move_constructible<__base>::value)
+    : __base(_VSTD::move(__c))
+{
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+deque<_Tp, _Allocator>::deque(deque&& __c, const allocator_type& __a)
+    : __base(_VSTD::move(__c), __a)
+{
+    if (__a != __c.__alloc())
+    {
+        typedef move_iterator<iterator> _Ip;
+        assign(_Ip(__c.begin()), _Ip(__c.end()));
+    }
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+deque<_Tp, _Allocator>&
+deque<_Tp, _Allocator>::operator=(deque&& __c)
+        _NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
+                   is_nothrow_move_assignable<allocator_type>::value)
+{
+    __move_assign(__c, integral_constant<bool,
+          __alloc_traits::propagate_on_container_move_assignment::value>());
+    return *this;
+}
+
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::__move_assign(deque& __c, false_type)
+{
+    if (__base::__alloc() != __c.__alloc())
+    {
+        typedef move_iterator<iterator> _Ip;
+        assign(_Ip(__c.begin()), _Ip(__c.end()));
+    }
+    else
+        __move_assign(__c, true_type());
+}
+
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::__move_assign(deque& __c, true_type)
+    _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
+{
+    clear();
+    shrink_to_fit();
+    __base::__move_assign(__c);
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Allocator>
+template <class _InputIter>
+void
+deque<_Tp, _Allocator>::assign(_InputIter __f, _InputIter __l,
+                               typename enable_if<__is_input_iterator<_InputIter>::value &&
+                                                 !__is_random_access_iterator<_InputIter>::value>::type*)
+{
+    iterator __i = __base::begin();
+    iterator __e = __base::end();
+    for (; __f != __l && __i != __e; ++__f, (void) ++__i)
+        *__i = *__f;
+    if (__f != __l)
+        __append(__f, __l);
+    else
+        __erase_to_end(__i);
+}
+
+template <class _Tp, class _Allocator>
+template <class _RAIter>
+void
+deque<_Tp, _Allocator>::assign(_RAIter __f, _RAIter __l,
+                               typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*)
+{
+    if (static_cast<size_type>(__l - __f) > __base::size())
+    {
+        _RAIter __m = __f + __base::size();
+        _VSTD::copy(__f, __m, __base::begin());
+        __append(__m, __l);
+    }
+    else
+        __erase_to_end(_VSTD::copy(__f, __l, __base::begin()));
+}
+
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::assign(size_type __n, const value_type& __v)
+{
+    if (__n > __base::size())
+    {
+        _VSTD::fill_n(__base::begin(), __base::size(), __v);
+        __n -= __base::size();
+        __append(__n, __v);
+    }
+    else
+        __erase_to_end(_VSTD::fill_n(__base::begin(), __n, __v));
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+_Allocator
+deque<_Tp, _Allocator>::get_allocator() const _NOEXCEPT
+{
+    return __base::__alloc();
+}
+
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::resize(size_type __n)
+{
+    if (__n > __base::size())
+        __append(__n - __base::size());
+    else if (__n < __base::size())
+        __erase_to_end(__base::begin() + __n);
+}
+
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::resize(size_type __n, const value_type& __v)
+{
+    if (__n > __base::size())
+        __append(__n - __base::size(), __v);
+    else if (__n < __base::size())
+        __erase_to_end(__base::begin() + __n);
+}
+
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT
+{
+    allocator_type& __a = __base::__alloc();
+    if (empty())
+    {
+        while (__base::__map_.size() > 0)
+        {
+            __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
+            __base::__map_.pop_back();
+        }
+        __base::__start_ = 0;
+    }
+    else
+    {
+        if (__front_spare() >= __base::__block_size)
+        {
+            __alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
+            __base::__map_.pop_front();
+            __base::__start_ -= __base::__block_size;
+        }
+        if (__back_spare() >= __base::__block_size)
+        {
+            __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
+            __base::__map_.pop_back();
+        }
+    }
+    __base::__map_.shrink_to_fit();
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+typename deque<_Tp, _Allocator>::reference
+deque<_Tp, _Allocator>::operator[](size_type __i)
+{
+    size_type __p = __base::__start_ + __i;
+    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+typename deque<_Tp, _Allocator>::const_reference
+deque<_Tp, _Allocator>::operator[](size_type __i) const
+{
+    size_type __p = __base::__start_ + __i;
+    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+typename deque<_Tp, _Allocator>::reference
+deque<_Tp, _Allocator>::at(size_type __i)
+{
+    if (__i >= __base::size())
+        __base::__throw_out_of_range();
+    size_type __p = __base::__start_ + __i;
+    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+typename deque<_Tp, _Allocator>::const_reference
+deque<_Tp, _Allocator>::at(size_type __i) const
+{
+    if (__i >= __base::size())
+        __base::__throw_out_of_range();
+    size_type __p = __base::__start_ + __i;
+    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+typename deque<_Tp, _Allocator>::reference
+deque<_Tp, _Allocator>::front()
+{
+    return *(*(__base::__map_.begin() + __base::__start_ / __base::__block_size)
+                                      + __base::__start_ % __base::__block_size);
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+typename deque<_Tp, _Allocator>::const_reference
+deque<_Tp, _Allocator>::front() const
+{
+    return *(*(__base::__map_.begin() + __base::__start_ / __base::__block_size)
+                                      + __base::__start_ % __base::__block_size);
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+typename deque<_Tp, _Allocator>::reference
+deque<_Tp, _Allocator>::back()
+{
+    size_type __p = __base::size() + __base::__start_ - 1;
+    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+typename deque<_Tp, _Allocator>::const_reference
+deque<_Tp, _Allocator>::back() const
+{
+    size_type __p = __base::size() + __base::__start_ - 1;
+    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
+}
+
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::push_back(const value_type& __v)
+{
+    allocator_type& __a = __base::__alloc();
+    if (__back_spare() == 0)
+        __add_back_capacity();
+    // __back_spare() >= 1
+    __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), __v);
+    ++__base::size();
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::push_back(value_type&& __v)
+{
+    allocator_type& __a = __base::__alloc();
+    if (__back_spare() == 0)
+        __add_back_capacity();
+    // __back_spare() >= 1
+    __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), _VSTD::move(__v));
+    ++__base::size();
+}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Allocator>
+template <class... _Args>
+void
+deque<_Tp, _Allocator>::emplace_back(_Args&&... __args)
+{
+    allocator_type& __a = __base::__alloc();
+    if (__back_spare() == 0)
+        __add_back_capacity();
+    // __back_spare() >= 1
+    __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), _VSTD::forward<_Args>(__args)...);
+    ++__base::size();
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::push_front(const value_type& __v)
+{
+    allocator_type& __a = __base::__alloc();
+    if (__front_spare() == 0)
+        __add_front_capacity();
+    // __front_spare() >= 1
+    __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), __v);
+    --__base::__start_;
+    ++__base::size();
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::push_front(value_type&& __v)
+{
+    allocator_type& __a = __base::__alloc();
+    if (__front_spare() == 0)
+        __add_front_capacity();
+    // __front_spare() >= 1
+    __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), _VSTD::move(__v));
+    --__base::__start_;
+    ++__base::size();
+}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Allocator>
+template <class... _Args>
+void
+deque<_Tp, _Allocator>::emplace_front(_Args&&... __args)
+{
+    allocator_type& __a = __base::__alloc();
+    if (__front_spare() == 0)
+        __add_front_capacity();
+    // __front_spare() >= 1
+    __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), _VSTD::forward<_Args>(__args)...);
+    --__base::__start_;
+    ++__base::size();
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Allocator>
+typename deque<_Tp, _Allocator>::iterator
+deque<_Tp, _Allocator>::insert(const_iterator __p, const value_type& __v)
+{
+    size_type __pos = __p - __base::begin();
+    size_type __to_end = __base::size() - __pos;
+    allocator_type& __a = __base::__alloc();
+    if (__pos < __to_end)
+    {   // insert by shifting things backward
+        if (__front_spare() == 0)
+            __add_front_capacity();
+        // __front_spare() >= 1
+        if (__pos == 0)
+        {
+            __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), __v);
+            --__base::__start_;
+            ++__base::size();
+        }
+        else
+        {
+            const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
+            iterator __b = __base::begin();
+            iterator __bm1 = _VSTD::prev(__b);
+            if (__vt == pointer_traits<const_pointer>::pointer_to(*__b))
+                __vt = pointer_traits<const_pointer>::pointer_to(*__bm1);
+            __alloc_traits::construct(__a, _VSTD::addressof(*__bm1), _VSTD::move(*__b));
+            --__base::__start_;
+            ++__base::size();
+            if (__pos > 1)
+                __b = __move_and_check(_VSTD::next(__b), __b + __pos, __b, __vt);
+            *__b = *__vt;
+        }
+    }
+    else
+    {   // insert by shifting things forward
+        if (__back_spare() == 0)
+            __add_back_capacity();
+        // __back_capacity >= 1
+        size_type __de = __base::size() - __pos;
+        if (__de == 0)
+        {
+            __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), __v);
+            ++__base::size();
+        }
+        else
+        {
+            const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
+            iterator __e = __base::end();
+            iterator __em1 = _VSTD::prev(__e);
+            if (__vt == pointer_traits<const_pointer>::pointer_to(*__em1))
+                __vt = pointer_traits<const_pointer>::pointer_to(*__e);
+            __alloc_traits::construct(__a, _VSTD::addressof(*__e), _VSTD::move(*__em1));
+            ++__base::size();
+            if (__de > 1)
+                __e = __move_backward_and_check(__e - __de, __em1, __e, __vt);
+            *--__e = *__vt;
+        }
+    }
+    return __base::begin() + __pos;
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Allocator>
+typename deque<_Tp, _Allocator>::iterator
+deque<_Tp, _Allocator>::insert(const_iterator __p, value_type&& __v)
+{
+    size_type __pos = __p - __base::begin();
+    size_type __to_end = __base::size() - __pos;
+    allocator_type& __a = __base::__alloc();
+    if (__pos < __to_end)
+    {   // insert by shifting things backward
+        if (__front_spare() == 0)
+            __add_front_capacity();
+        // __front_spare() >= 1
+        if (__pos == 0)
+        {
+            __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), _VSTD::move(__v));
+            --__base::__start_;
+            ++__base::size();
+        }
+        else
+        {
+            iterator __b = __base::begin();
+            iterator __bm1 = _VSTD::prev(__b);
+            __alloc_traits::construct(__a, _VSTD::addressof(*__bm1), _VSTD::move(*__b));
+            --__base::__start_;
+            ++__base::size();
+            if (__pos > 1)
+                __b = _VSTD::move(_VSTD::next(__b), __b + __pos, __b);
+            *__b = _VSTD::move(__v);
+        }
+    }
+    else
+    {   // insert by shifting things forward
+        if (__back_spare() == 0)
+            __add_back_capacity();
+        // __back_capacity >= 1
+        size_type __de = __base::size() - __pos;
+        if (__de == 0)
+        {
+            __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), _VSTD::move(__v));
+            ++__base::size();
+        }
+        else
+        {
+            iterator __e = __base::end();
+            iterator __em1 = _VSTD::prev(__e);
+            __alloc_traits::construct(__a, _VSTD::addressof(*__e), _VSTD::move(*__em1));
+            ++__base::size();
+            if (__de > 1)
+                __e = _VSTD::move_backward(__e - __de, __em1, __e);
+            *--__e = _VSTD::move(__v);
+        }
+    }
+    return __base::begin() + __pos;
+}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Allocator>
+template <class... _Args>
+typename deque<_Tp, _Allocator>::iterator
+deque<_Tp, _Allocator>::emplace(const_iterator __p, _Args&&... __args)
+{
+    size_type __pos = __p - __base::begin();
+    size_type __to_end = __base::size() - __pos;
+    allocator_type& __a = __base::__alloc();
+    if (__pos < __to_end)
+    {   // insert by shifting things backward
+        if (__front_spare() == 0)
+            __add_front_capacity();
+        // __front_spare() >= 1
+        if (__pos == 0)
+        {
+            __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), _VSTD::forward<_Args>(__args)...);
+            --__base::__start_;
+            ++__base::size();
+        }
+        else
+        {
+            value_type __tmp(_VSTD::forward<_Args>(__args)...);
+            iterator __b = __base::begin();
+            iterator __bm1 = _VSTD::prev(__b);
+            __alloc_traits::construct(__a, _VSTD::addressof(*__bm1), _VSTD::move(*__b));
+            --__base::__start_;
+            ++__base::size();
+            if (__pos > 1)
+                __b = _VSTD::move(_VSTD::next(__b), __b + __pos, __b);
+            *__b = _VSTD::move(__tmp);
+        }
+    }
+    else
+    {   // insert by shifting things forward
+        if (__back_spare() == 0)
+            __add_back_capacity();
+        // __back_capacity >= 1
+        size_type __de = __base::size() - __pos;
+        if (__de == 0)
+        {
+            __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), _VSTD::forward<_Args>(__args)...);
+            ++__base::size();
+        }
+        else
+        {
+            value_type __tmp(_VSTD::forward<_Args>(__args)...);
+            iterator __e = __base::end();
+            iterator __em1 = _VSTD::prev(__e);
+            __alloc_traits::construct(__a, _VSTD::addressof(*__e), _VSTD::move(*__em1));
+            ++__base::size();
+            if (__de > 1)
+                __e = _VSTD::move_backward(__e - __de, __em1, __e);
+            *--__e = _VSTD::move(__tmp);
+        }
+    }
+    return __base::begin() + __pos;
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Allocator>
+typename deque<_Tp, _Allocator>::iterator
+deque<_Tp, _Allocator>::insert(const_iterator __p, size_type __n, const value_type& __v)
+{
+    size_type __pos = __p - __base::begin();
+    size_type __to_end = __base::size() - __pos;
+    allocator_type& __a = __base::__alloc();
+    if (__pos < __to_end)
+    {   // insert by shifting things backward
+        if (__n > __front_spare())
+            __add_front_capacity(__n - __front_spare());
+        // __n <= __front_spare()
+        iterator __old_begin = __base::begin();
+        iterator __i = __old_begin;
+        if (__n > __pos)
+        {
+            for (size_type __m = __n - __pos; __m; --__m, --__base::__start_, ++__base::size())
+                __alloc_traits::construct(__a, _VSTD::addressof(*--__i), __v);
+            __n = __pos;
+        }
+        if (__n > 0)
+        {
+            const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
+            iterator __obn = __old_begin + __n;
+            __move_construct_backward_and_check(__old_begin, __obn, __i, __vt);
+            if (__n < __pos)
+                __old_begin = __move_and_check(__obn, __old_begin + __pos, __old_begin, __vt);
+            _VSTD::fill_n(__old_begin, __n, *__vt);
+        }
+    }
+    else
+    {   // insert by shifting things forward
+        size_type __back_capacity = __back_spare();
+        if (__n > __back_capacity)
+            __add_back_capacity(__n - __back_capacity);
+        // __n <= __back_capacity
+        iterator __old_end = __base::end();
+        iterator __i = __old_end;
+        size_type __de = __base::size() - __pos;
+        if (__n > __de)
+        {
+            for (size_type __m = __n - __de; __m; --__m, ++__i, ++__base::size())
+                __alloc_traits::construct(__a, _VSTD::addressof(*__i), __v);
+            __n = __de;
+        }
+        if (__n > 0)
+        {
+            const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
+            iterator __oen = __old_end - __n;
+            __move_construct_and_check(__oen, __old_end, __i, __vt);
+            if (__n < __de)
+                __old_end = __move_backward_and_check(__old_end - __de, __oen, __old_end, __vt);
+            _VSTD::fill_n(__old_end - __n, __n, *__vt);
+        }
+    }
+    return __base::begin() + __pos;
+}
+
+template <class _Tp, class _Allocator>
+template <class _InputIter>
+typename deque<_Tp, _Allocator>::iterator
+deque<_Tp, _Allocator>::insert(const_iterator __p, _InputIter __f, _InputIter __l,
+                               typename enable_if<__is_input_iterator<_InputIter>::value
+                                               &&!__is_forward_iterator<_InputIter>::value>::type*)
+{
+    __split_buffer<value_type, allocator_type&> __buf(__base::__alloc());
+    __buf.__construct_at_end(__f, __l);
+    typedef typename __split_buffer<value_type, allocator_type&>::iterator __bi;
+    return insert(__p, move_iterator<__bi>(__buf.begin()), move_iterator<__bi>(__buf.end()));
+}
+
+template <class _Tp, class _Allocator>
+template <class _ForwardIterator>
+typename deque<_Tp, _Allocator>::iterator
+deque<_Tp, _Allocator>::insert(const_iterator __p, _ForwardIterator __f, _ForwardIterator __l,
+                               typename enable_if<__is_forward_iterator<_ForwardIterator>::value
+                                               &&!__is_bidirectional_iterator<_ForwardIterator>::value>::type*)
+{
+    size_type __n = _VSTD::distance(__f, __l);
+    __split_buffer<value_type, allocator_type&> __buf(__n, 0, __base::__alloc());
+    __buf.__construct_at_end(__f, __l);
+    typedef typename __split_buffer<value_type, allocator_type&>::iterator __fwd;
+    return insert(__p, move_iterator<__fwd>(__buf.begin()), move_iterator<__fwd>(__buf.end()));
+}
+
+template <class _Tp, class _Allocator>
+template <class _BiIter>
+typename deque<_Tp, _Allocator>::iterator
+deque<_Tp, _Allocator>::insert(const_iterator __p, _BiIter __f, _BiIter __l,
+                               typename enable_if<__is_bidirectional_iterator<_BiIter>::value>::type*)
+{
+    size_type __n = _VSTD::distance(__f, __l);
+    size_type __pos = __p - __base::begin();
+    size_type __to_end = __base::size() - __pos;
+    allocator_type& __a = __base::__alloc();
+    if (__pos < __to_end)
+    {   // insert by shifting things backward
+        if (__n > __front_spare())
+            __add_front_capacity(__n - __front_spare());
+        // __n <= __front_spare()
+        iterator __old_begin = __base::begin();
+        iterator __i = __old_begin;
+        _BiIter __m = __f;
+        if (__n > __pos)
+        {
+            __m = __pos < __n / 2 ? _VSTD::prev(__l, __pos) : _VSTD::next(__f, __n - __pos);
+            for (_BiIter __j = __m; __j != __f; --__base::__start_, ++__base::size())
+                __alloc_traits::construct(__a, _VSTD::addressof(*--__i), *--__j);
+            __n = __pos;
+        }
+        if (__n > 0)
+        {
+            iterator __obn = __old_begin + __n;
+            for (iterator __j = __obn; __j != __old_begin;)
+            {
+                __alloc_traits::construct(__a, _VSTD::addressof(*--__i), _VSTD::move(*--__j));
+                --__base::__start_;
+                ++__base::size();
+            }
+            if (__n < __pos)
+                __old_begin = _VSTD::move(__obn, __old_begin + __pos, __old_begin);
+            _VSTD::copy(__m, __l, __old_begin);
+        }
+    }
+    else
+    {   // insert by shifting things forward
+        size_type __back_capacity = __back_spare();
+        if (__n > __back_capacity)
+            __add_back_capacity(__n - __back_capacity);
+        // __n <= __back_capacity
+        iterator __old_end = __base::end();
+        iterator __i = __old_end;
+        _BiIter __m = __l;
+        size_type __de = __base::size() - __pos;
+        if (__n > __de)
+        {
+            __m = __de < __n / 2 ? _VSTD::next(__f, __de) : _VSTD::prev(__l, __n - __de);
+            for (_BiIter __j = __m; __j != __l; ++__i, (void) ++__j, ++__base::size())
+                __alloc_traits::construct(__a, _VSTD::addressof(*__i), *__j);
+            __n = __de;
+        }
+        if (__n > 0)
+        {
+            iterator __oen = __old_end - __n;
+            for (iterator __j = __oen; __j != __old_end; ++__i, ++__j, ++__base::size())
+                __alloc_traits::construct(__a, _VSTD::addressof(*__i), _VSTD::move(*__j));
+            if (__n < __de)
+                __old_end = _VSTD::move_backward(__old_end - __de, __oen, __old_end);
+            _VSTD::copy_backward(__f, __m, __old_end);
+        }
+    }
+    return __base::begin() + __pos;
+}
+
+template <class _Tp, class _Allocator>
+template <class _InpIter>
+void
+deque<_Tp, _Allocator>::__append(_InpIter __f, _InpIter __l,
+                                 typename enable_if<__is_input_iterator<_InpIter>::value &&
+                                                   !__is_forward_iterator<_InpIter>::value>::type*)
+{
+    for (; __f != __l; ++__f)
+        push_back(*__f);
+}
+
+template <class _Tp, class _Allocator>
+template <class _ForIter>
+void
+deque<_Tp, _Allocator>::__append(_ForIter __f, _ForIter __l,
+                                 typename enable_if<__is_forward_iterator<_ForIter>::value>::type*)
+{
+    size_type __n = _VSTD::distance(__f, __l);
+    allocator_type& __a = __base::__alloc();
+    size_type __back_capacity = __back_spare();
+    if (__n > __back_capacity)
+        __add_back_capacity(__n - __back_capacity);
+    // __n <= __back_capacity
+    for (iterator __i = __base::end(); __f != __l; ++__i, (void) ++__f, ++__base::size())
+        __alloc_traits::construct(__a, _VSTD::addressof(*__i), *__f);
+}
+
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::__append(size_type __n)
+{
+    allocator_type& __a = __base::__alloc();
+    size_type __back_capacity = __back_spare();
+    if (__n > __back_capacity)
+        __add_back_capacity(__n - __back_capacity);
+    // __n <= __back_capacity
+    for (iterator __i = __base::end(); __n; --__n, ++__i, ++__base::size())
+        __alloc_traits::construct(__a, _VSTD::addressof(*__i));
+}
+
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::__append(size_type __n, const value_type& __v)
+{
+    allocator_type& __a = __base::__alloc();
+    size_type __back_capacity = __back_spare();
+    if (__n > __back_capacity)
+        __add_back_capacity(__n - __back_capacity);
+    // __n <= __back_capacity
+    for (iterator __i = __base::end(); __n; --__n, ++__i, ++__base::size())
+        __alloc_traits::construct(__a, _VSTD::addressof(*__i), __v);
+}
+
+// Create front capacity for one block of elements.
+// Strong guarantee.  Either do it or don't touch anything.
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::__add_front_capacity()
+{
+    allocator_type& __a = __base::__alloc();
+    if (__back_spare() >= __base::__block_size)
+    {
+        __base::__start_ += __base::__block_size;
+        pointer __pt = __base::__map_.back();
+        __base::__map_.pop_back();
+        __base::__map_.push_front(__pt);
+    }
+    // Else if __base::__map_.size() < __base::__map_.capacity() then we need to allocate 1 buffer
+    else if (__base::__map_.size() < __base::__map_.capacity())
+    {   // we can put the new buffer into the map, but don't shift things around
+        // until all buffers are allocated.  If we throw, we don't need to fix
+        // anything up (any added buffers are undetectible)
+        if (__base::__map_.__front_spare() > 0)
+            __base::__map_.push_front(__alloc_traits::allocate(__a, __base::__block_size));
+        else
+        {
+            __base::__map_.push_back(__alloc_traits::allocate(__a, __base::__block_size));
+            // Done allocating, reorder capacity
+            pointer __pt = __base::__map_.back();
+            __base::__map_.pop_back();
+            __base::__map_.push_front(__pt);
+        }
+        __base::__start_ = __base::__map_.size() == 1 ?
+                               __base::__block_size / 2 :
+                               __base::__start_ + __base::__block_size;
+    }
+    // Else need to allocate 1 buffer, *and* we need to reallocate __map_.
+    else
+    {
+        __split_buffer<pointer, typename __base::__pointer_allocator&>
+            __buf(max<size_type>(2 * __base::__map_.capacity(), 1),
+                  0, __base::__map_.__alloc());
+
+        typedef __allocator_destructor<_Allocator> _Dp;
+        unique_ptr<pointer, _Dp> __hold(
+            __alloc_traits::allocate(__a, __base::__block_size),
+                _Dp(__a, __base::__block_size));
+        __buf.push_back(__hold.get());
+        __hold.release();
+    
+        for (typename __base::__map_pointer __i = __base::__map_.begin();
+                __i != __base::__map_.end(); ++__i)
+            __buf.push_back(*__i);
+        _VSTD::swap(__base::__map_.__first_, __buf.__first_);
+        _VSTD::swap(__base::__map_.__begin_, __buf.__begin_);
+        _VSTD::swap(__base::__map_.__end_, __buf.__end_);
+        _VSTD::swap(__base::__map_.__end_cap(), __buf.__end_cap());
+        __base::__start_ = __base::__map_.size() == 1 ?
+                               __base::__block_size / 2 :
+                               __base::__start_ + __base::__block_size;
+    }
+}
+
+// Create front capacity for __n elements.
+// Strong guarantee.  Either do it or don't touch anything.
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::__add_front_capacity(size_type __n)
+{
+    allocator_type& __a = __base::__alloc();
+    size_type __nb = __recommend_blocks(__n + __base::__map_.empty());
+    // Number of unused blocks at back:
+    size_type __back_capacity = __back_spare() / __base::__block_size;
+    __back_capacity = _VSTD::min(__back_capacity, __nb);  // don't take more than you need
+    __nb -= __back_capacity;  // number of blocks need to allocate
+    // If __nb == 0, then we have sufficient capacity.
+    if (__nb == 0)
+    {
+        __base::__start_ += __base::__block_size * __back_capacity;
+        for (; __back_capacity > 0; --__back_capacity)
+        {
+            pointer __pt = __base::__map_.back();
+            __base::__map_.pop_back();
+            __base::__map_.push_front(__pt);
+        }
+    }
+    // Else if __nb <= __map_.capacity() - __map_.size() then we need to allocate __nb buffers
+    else if (__nb <= __base::__map_.capacity() - __base::__map_.size())
+    {   // we can put the new buffers into the map, but don't shift things around
+        // until all buffers are allocated.  If we throw, we don't need to fix
+        // anything up (any added buffers are undetectible)
+        for (; __nb > 0; --__nb, __base::__start_ += __base::__block_size - (__base::__map_.size() == 1))
+        {
+            if (__base::__map_.__front_spare() == 0)
+                break;
+            __base::__map_.push_front(__alloc_traits::allocate(__a, __base::__block_size));
+        }
+        for (; __nb > 0; --__nb, ++__back_capacity)
+            __base::__map_.push_back(__alloc_traits::allocate(__a, __base::__block_size));
+        // Done allocating, reorder capacity
+        __base::__start_ += __back_capacity * __base::__block_size;
+        for (; __back_capacity > 0; --__back_capacity)
+        {
+            pointer __pt = __base::__map_.back();
+            __base::__map_.pop_back();
+            __base::__map_.push_front(__pt);
+        }
+    }
+    // Else need to allocate __nb buffers, *and* we need to reallocate __map_.
+    else
+    {
+        size_type __ds = (__nb + __back_capacity) * __base::__block_size - __base::__map_.empty();
+        __split_buffer<pointer, typename __base::__pointer_allocator&>
+            __buf(max<size_type>(2* __base::__map_.capacity(),
+                                 __nb + __base::__map_.size()),
+                  0, __base::__map_.__alloc());
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        try
+        {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            for (; __nb > 0; --__nb)
+                __buf.push_back(__alloc_traits::allocate(__a, __base::__block_size));
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        }
+        catch (...)
+        {
+            for (typename __base::__map_pointer __i = __buf.begin();
+                    __i != __buf.end(); ++__i)
+                __alloc_traits::deallocate(__a, *__i, __base::__block_size);
+            throw;
+        }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        for (; __back_capacity > 0; --__back_capacity)
+        {
+            __buf.push_back(__base::__map_.back());
+            __base::__map_.pop_back();
+        }
+        for (typename __base::__map_pointer __i = __base::__map_.begin();
+                __i != __base::__map_.end(); ++__i)
+            __buf.push_back(*__i);
+        _VSTD::swap(__base::__map_.__first_, __buf.__first_);
+        _VSTD::swap(__base::__map_.__begin_, __buf.__begin_);
+        _VSTD::swap(__base::__map_.__end_, __buf.__end_);
+        _VSTD::swap(__base::__map_.__end_cap(), __buf.__end_cap());
+        __base::__start_ += __ds;
+    }
+}
+
+// Create back capacity for one block of elements.
+// Strong guarantee.  Either do it or don't touch anything.
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::__add_back_capacity()
+{
+    allocator_type& __a = __base::__alloc();
+    if (__front_spare() >= __base::__block_size)
+    {
+        __base::__start_ -= __base::__block_size;
+        pointer __pt = __base::__map_.front();
+        __base::__map_.pop_front();
+        __base::__map_.push_back(__pt);
+    }
+    // Else if __nb <= __map_.capacity() - __map_.size() then we need to allocate __nb buffers
+    else if (__base::__map_.size() < __base::__map_.capacity())
+    {   // we can put the new buffer into the map, but don't shift things around
+        // until it is allocated.  If we throw, we don't need to fix
+        // anything up (any added buffers are undetectible)
+        if (__base::__map_.__back_spare() != 0)
+            __base::__map_.push_back(__alloc_traits::allocate(__a, __base::__block_size));
+        else
+        {
+            __base::__map_.push_front(__alloc_traits::allocate(__a, __base::__block_size));
+            // Done allocating, reorder capacity
+            pointer __pt = __base::__map_.front();
+            __base::__map_.pop_front();
+            __base::__map_.push_back(__pt);
+        }
+    }
+    // Else need to allocate 1 buffer, *and* we need to reallocate __map_.
+    else
+    {
+        __split_buffer<pointer, typename __base::__pointer_allocator&>
+            __buf(max<size_type>(2* __base::__map_.capacity(), 1),
+                  __base::__map_.size(),
+                  __base::__map_.__alloc());
+
+        typedef __allocator_destructor<_Allocator> _Dp;
+        unique_ptr<pointer, _Dp> __hold(
+            __alloc_traits::allocate(__a, __base::__block_size),
+                _Dp(__a, __base::__block_size));
+        __buf.push_back(__hold.get());
+        __hold.release();
+
+        for (typename __base::__map_pointer __i = __base::__map_.end();
+                __i != __base::__map_.begin();)
+            __buf.push_front(*--__i);
+        _VSTD::swap(__base::__map_.__first_, __buf.__first_);
+        _VSTD::swap(__base::__map_.__begin_, __buf.__begin_);
+        _VSTD::swap(__base::__map_.__end_, __buf.__end_);
+        _VSTD::swap(__base::__map_.__end_cap(), __buf.__end_cap());
+    }
+}
+
+// Create back capacity for __n elements.
+// Strong guarantee.  Either do it or don't touch anything.
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::__add_back_capacity(size_type __n)
+{
+    allocator_type& __a = __base::__alloc();
+    size_type __nb = __recommend_blocks(__n + __base::__map_.empty());
+    // Number of unused blocks at front:
+    size_type __front_capacity = __front_spare() / __base::__block_size;
+    __front_capacity = _VSTD::min(__front_capacity, __nb);  // don't take more than you need
+    __nb -= __front_capacity;  // number of blocks need to allocate
+    // If __nb == 0, then we have sufficient capacity.
+    if (__nb == 0)
+    {
+        __base::__start_ -= __base::__block_size * __front_capacity;
+        for (; __front_capacity > 0; --__front_capacity)
+        {
+            pointer __pt = __base::__map_.front();
+            __base::__map_.pop_front();
+            __base::__map_.push_back(__pt);
+        }
+    }
+    // Else if __nb <= __map_.capacity() - __map_.size() then we need to allocate __nb buffers
+    else if (__nb <= __base::__map_.capacity() - __base::__map_.size())
+    {   // we can put the new buffers into the map, but don't shift things around
+        // until all buffers are allocated.  If we throw, we don't need to fix
+        // anything up (any added buffers are undetectible)
+        for (; __nb > 0; --__nb)
+        {
+            if (__base::__map_.__back_spare() == 0)
+                break;
+            __base::__map_.push_back(__alloc_traits::allocate(__a, __base::__block_size));
+        }
+        for (; __nb > 0; --__nb, ++__front_capacity, __base::__start_ +=
+                                 __base::__block_size - (__base::__map_.size() == 1))
+            __base::__map_.push_front(__alloc_traits::allocate(__a, __base::__block_size));
+        // Done allocating, reorder capacity
+        __base::__start_ -= __base::__block_size * __front_capacity;
+        for (; __front_capacity > 0; --__front_capacity)
+        {
+            pointer __pt = __base::__map_.front();
+            __base::__map_.pop_front();
+            __base::__map_.push_back(__pt);
+        }
+    }
+    // Else need to allocate __nb buffers, *and* we need to reallocate __map_.
+    else
+    {
+        size_type __ds = __front_capacity * __base::__block_size;
+        __split_buffer<pointer, typename __base::__pointer_allocator&>
+            __buf(max<size_type>(2* __base::__map_.capacity(),
+                                 __nb + __base::__map_.size()),
+                  __base::__map_.size() - __front_capacity,
+                  __base::__map_.__alloc());
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        try
+        {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            for (; __nb > 0; --__nb)
+                __buf.push_back(__alloc_traits::allocate(__a, __base::__block_size));
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        }
+        catch (...)
+        {
+            for (typename __base::__map_pointer __i = __buf.begin();
+                    __i != __buf.end(); ++__i)
+                __alloc_traits::deallocate(__a, *__i, __base::__block_size);
+            throw;
+        }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        for (; __front_capacity > 0; --__front_capacity)
+        {
+            __buf.push_back(__base::__map_.front());
+            __base::__map_.pop_front();
+        }
+        for (typename __base::__map_pointer __i = __base::__map_.end();
+                __i != __base::__map_.begin();)
+            __buf.push_front(*--__i);
+        _VSTD::swap(__base::__map_.__first_, __buf.__first_);
+        _VSTD::swap(__base::__map_.__begin_, __buf.__begin_);
+        _VSTD::swap(__base::__map_.__end_, __buf.__end_);
+        _VSTD::swap(__base::__map_.__end_cap(), __buf.__end_cap());
+        __base::__start_ -= __ds;
+    }
+}
+
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::pop_front()
+{
+    allocator_type& __a = __base::__alloc();
+    __alloc_traits::destroy(__a, __to_raw_pointer(*(__base::__map_.begin() +
+                                                    __base::__start_ / __base::__block_size) +
+                                                    __base::__start_ % __base::__block_size));
+    --__base::size();
+    if (++__base::__start_ >= 2 * __base::__block_size)
+    {
+        __alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
+        __base::__map_.pop_front();
+        __base::__start_ -= __base::__block_size;
+    }
+}
+
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::pop_back()
+{
+    allocator_type& __a = __base::__alloc();
+    size_type __p = __base::size() + __base::__start_ - 1;
+    __alloc_traits::destroy(__a, __to_raw_pointer(*(__base::__map_.begin() +
+                                                    __p / __base::__block_size) +
+                                                    __p % __base::__block_size));
+    --__base::size();
+    if (__back_spare() >= 2 * __base::__block_size)
+    {
+        __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
+        __base::__map_.pop_back();
+    }
+}
+
+// move assign [__f, __l) to [__r, __r + (__l-__f)).
+// If __vt points into [__f, __l), then subtract (__f - __r) from __vt.
+template <class _Tp, class _Allocator>
+typename deque<_Tp, _Allocator>::iterator
+deque<_Tp, _Allocator>::__move_and_check(iterator __f, iterator __l, iterator __r,
+                                         const_pointer& __vt)
+{
+    // as if
+    //   for (; __f != __l; ++__f, ++__r)
+    //       *__r = _VSTD::move(*__f);
+    difference_type __n = __l - __f;
+    while (__n > 0)
+    {
+        pointer __fb = __f.__ptr_;
+        pointer __fe = *__f.__m_iter_ + __base::__block_size;
+        difference_type __bs = __fe - __fb;
+        if (__bs > __n)
+        {
+            __bs = __n;
+            __fe = __fb + __bs;
+        }
+        if (__fb <= __vt && __vt < __fe)
+            __vt = (const_iterator(static_cast<__map_const_pointer>(__f.__m_iter_), __vt) -= __f - __r).__ptr_;
+        __r = _VSTD::move(__fb, __fe, __r);
+        __n -= __bs;
+        __f += __bs;
+    }
+    return __r;
+}
+
+// move assign [__f, __l) to [__r - (__l-__f), __r) backwards.
+// If __vt points into [__f, __l), then add (__r - __l) to __vt.
+template <class _Tp, class _Allocator>
+typename deque<_Tp, _Allocator>::iterator
+deque<_Tp, _Allocator>::__move_backward_and_check(iterator __f, iterator __l, iterator __r,
+                                                  const_pointer& __vt)
+{
+    // as if
+    //   while (__f != __l)
+    //       *--__r = _VSTD::move(*--__l);
+    difference_type __n = __l - __f;
+    while (__n > 0)
+    {
+        --__l;
+        pointer __lb = *__l.__m_iter_;
+        pointer __le = __l.__ptr_ + 1;
+        difference_type __bs = __le - __lb;
+        if (__bs > __n)
+        {
+            __bs = __n;
+            __lb = __le - __bs;
+        }
+        if (__lb <= __vt && __vt < __le)
+            __vt = (const_iterator(static_cast<__map_const_pointer>(__l.__m_iter_), __vt) += __r - __l - 1).__ptr_;
+        __r = _VSTD::move_backward(__lb, __le, __r);
+        __n -= __bs;
+        __l -= __bs - 1;
+    }
+    return __r;
+}
+
+// move construct [__f, __l) to [__r, __r + (__l-__f)).
+// If __vt points into [__f, __l), then add (__r - __f) to __vt.
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::__move_construct_and_check(iterator __f, iterator __l,
+                                                   iterator __r, const_pointer& __vt)
+{
+    allocator_type& __a = __base::__alloc();
+    // as if
+    //   for (; __f != __l; ++__r, ++__f, ++__base::size())
+    //       __alloc_traits::construct(__a, _VSTD::addressof(*__r), _VSTD::move(*__f));
+    difference_type __n = __l - __f;
+    while (__n > 0)
+    {
+        pointer __fb = __f.__ptr_;
+        pointer __fe = *__f.__m_iter_ + __base::__block_size;
+        difference_type __bs = __fe - __fb;
+        if (__bs > __n)
+        {
+            __bs = __n;
+            __fe = __fb + __bs;
+        }
+        if (__fb <= __vt && __vt < __fe)
+            __vt = (const_iterator(static_cast<__map_const_pointer>(__f.__m_iter_), __vt) += __r - __f).__ptr_;
+        for (; __fb != __fe; ++__fb, ++__r, ++__base::size())
+            __alloc_traits::construct(__a, _VSTD::addressof(*__r), _VSTD::move(*__fb));
+        __n -= __bs;
+        __f += __bs;
+    }
+}
+
+// move construct [__f, __l) to [__r - (__l-__f), __r) backwards.
+// If __vt points into [__f, __l), then subtract (__l - __r) from __vt.
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::__move_construct_backward_and_check(iterator __f, iterator __l,
+                                                            iterator __r, const_pointer& __vt)
+{
+    allocator_type& __a = __base::__alloc();
+    // as if
+    //   for (iterator __j = __l; __j != __f;)
+    //   {
+    //       __alloc_traitsconstruct(__a, _VSTD::addressof(*--__r), _VSTD::move(*--__j));
+    //       --__base::__start_;
+    //       ++__base::size();
+    //   }
+    difference_type __n = __l - __f;
+    while (__n > 0)
+    {
+        --__l;
+        pointer __lb = *__l.__m_iter_;
+        pointer __le = __l.__ptr_ + 1;
+        difference_type __bs = __le - __lb;
+        if (__bs > __n)
+        {
+            __bs = __n;
+            __lb = __le - __bs;
+        }
+        if (__lb <= __vt && __vt < __le)
+            __vt = (const_iterator(static_cast<__map_const_pointer>(__l.__m_iter_), __vt) -= __l - __r + 1).__ptr_;
+        while (__le != __lb)
+        {
+            __alloc_traits::construct(__a, _VSTD::addressof(*--__r), _VSTD::move(*--__le));
+            --__base::__start_;
+            ++__base::size();
+        }
+        __n -= __bs;
+        __l -= __bs - 1;
+    }
+}
+
+template <class _Tp, class _Allocator>
+typename deque<_Tp, _Allocator>::iterator
+deque<_Tp, _Allocator>::erase(const_iterator __f)
+{
+    iterator __b = __base::begin();
+    difference_type __pos = __f - __b;
+    iterator __p = __b + __pos;
+    allocator_type& __a = __base::__alloc();
+    if (__pos <= (__base::size() - 1) / 2)
+    {   // erase from front
+        _VSTD::move_backward(__b, __p, _VSTD::next(__p));
+        __alloc_traits::destroy(__a, _VSTD::addressof(*__b));
+        --__base::size();
+        ++__base::__start_;
+        if (__front_spare() >= 2 * __base::__block_size)
+        {
+            __alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
+            __base::__map_.pop_front();
+            __base::__start_ -= __base::__block_size;
+        }
+    }
+    else
+    {   // erase from back
+        iterator __i = _VSTD::move(_VSTD::next(__p), __base::end(), __p);
+        __alloc_traits::destroy(__a, _VSTD::addressof(*__i));
+        --__base::size();
+        if (__back_spare() >= 2 * __base::__block_size)
+        {
+            __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
+            __base::__map_.pop_back();
+        }
+    }
+    return __base::begin() + __pos;
+}
+
+template <class _Tp, class _Allocator>
+typename deque<_Tp, _Allocator>::iterator
+deque<_Tp, _Allocator>::erase(const_iterator __f, const_iterator __l)
+{
+    difference_type __n = __l - __f;
+    iterator __b = __base::begin();
+    difference_type __pos = __f - __b;
+    iterator __p = __b + __pos;
+    if (__n > 0)
+    {
+        allocator_type& __a = __base::__alloc();
+        if (__pos <= (__base::size() - __n) / 2)
+        {   // erase from front
+            iterator __i = _VSTD::move_backward(__b, __p, __p + __n);
+            for (; __b != __i; ++__b)
+                __alloc_traits::destroy(__a, _VSTD::addressof(*__b));
+            __base::size() -= __n;
+            __base::__start_ += __n;
+            while (__front_spare() >= 2 * __base::__block_size)
+            {
+                __alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
+                __base::__map_.pop_front();
+                __base::__start_ -= __base::__block_size;
+            }
+        }
+        else
+        {   // erase from back
+            iterator __i = _VSTD::move(__p + __n, __base::end(), __p);
+            for (iterator __e = __base::end(); __i != __e; ++__i)
+                __alloc_traits::destroy(__a, _VSTD::addressof(*__i));
+            __base::size() -= __n;
+            while (__back_spare() >= 2 * __base::__block_size)
+            {
+                __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
+                __base::__map_.pop_back();
+            }
+        }
+    }
+    return __base::begin() + __pos;
+}
+
+template <class _Tp, class _Allocator>
+void
+deque<_Tp, _Allocator>::__erase_to_end(const_iterator __f)
+{
+    iterator __e = __base::end();
+    difference_type __n = __e - __f;
+    if (__n > 0)
+    {
+        allocator_type& __a = __base::__alloc();
+        iterator __b = __base::begin();
+        difference_type __pos = __f - __b;
+        for (iterator __p = __b + __pos; __p != __e; ++__p)
+            __alloc_traits::destroy(__a, _VSTD::addressof(*__p));
+        __base::size() -= __n;
+        while (__back_spare() >= 2 * __base::__block_size)
+        {
+            __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
+            __base::__map_.pop_back();
+        }
+    }
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+deque<_Tp, _Allocator>::swap(deque& __c)
+#if _LIBCPP_STD_VER >= 14
+        _NOEXCEPT
+#else
+        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || 
+                    __is_nothrow_swappable<allocator_type>::value)
+#endif
+{
+    __base::swap(__c);
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+deque<_Tp, _Allocator>::clear() _NOEXCEPT
+{
+    __base::clear();
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
+{
+    const typename deque<_Tp, _Allocator>::size_type __sz = __x.size();
+    return __sz == __y.size() && _VSTD::equal(__x.begin(), __x.end(), __y.begin());
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
+{
+    return !(__x == __y);
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator< (const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
+{
+    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator> (const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
+{
+    return __y < __x;
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
+{
+    return !(__x < __y);
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
+{
+    return !(__y < __x);
+}
+
+template <class _Tp, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(deque<_Tp, _Allocator>& __x, deque<_Tp, _Allocator>& __y)
+    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
+{
+    __x.swap(__y);
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_DEQUE

diff --git a/libcxx/include/exception b/libcxx/include/exception
new file mode 100644
index 0000000..5a905e7
--- /dev/null
+++ b/libcxx/include/exception

@@ -0,0 +1,254 @@
+// -*- C++ -*-
+//===-------------------------- exception ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_EXCEPTION
+#define _LIBCPP_EXCEPTION
+
+/*
+    exception synopsis
+
+namespace std
+{
+
+class exception
+{
+public:
+    exception() noexcept;
+    exception(const exception&) noexcept;
+    exception& operator=(const exception&) noexcept;
+    virtual ~exception() noexcept;
+    virtual const char* what() const noexcept;
+};
+
+class bad_exception
+    : public exception
+{
+public:
+    bad_exception() noexcept;
+    bad_exception(const bad_exception&) noexcept;
+    bad_exception& operator=(const bad_exception&) noexcept;
+    virtual ~bad_exception() noexcept;
+    virtual const char* what() const noexcept;
+};
+
+typedef void (*unexpected_handler)();
+unexpected_handler set_unexpected(unexpected_handler  f ) noexcept;
+unexpected_handler get_unexpected() noexcept;
+[[noreturn]] void unexpected();
+
+typedef void (*terminate_handler)();
+terminate_handler set_terminate(terminate_handler  f ) noexcept;
+terminate_handler get_terminate() noexcept;
+[[noreturn]] void terminate() noexcept;
+
+bool uncaught_exception()  noexcept;
+int  uncaught_exceptions() noexcept;  // C++17
+
+typedef unspecified exception_ptr;
+
+exception_ptr current_exception() noexcept;
+void rethrow_exception [[noreturn]] (exception_ptr p);
+template<class E> exception_ptr make_exception_ptr(E e) noexcept;
+
+class nested_exception
+{
+public:
+    nested_exception() noexcept;
+    nested_exception(const nested_exception&) noexcept = default;
+    nested_exception& operator=(const nested_exception&) noexcept = default;
+    virtual ~nested_exception() = default;
+
+    // access functions
+    [[noreturn]] void rethrow_nested() const;
+    exception_ptr nested_ptr() const noexcept;
+};
+
+template <class T> [[noreturn]] void throw_with_nested(T&& t);
+template <class E> void rethrow_if_nested(const E& e);
+
+}  // std
+
+*/
+
+#include <__config>
+#include <cstddef>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+namespace std  // purposefully not using versioning namespace
+{
+
+class _LIBCPP_EXCEPTION_ABI exception
+{
+public:
+    _LIBCPP_INLINE_VISIBILITY exception() _NOEXCEPT {}
+    virtual ~exception() _NOEXCEPT;
+    virtual const char* what() const _NOEXCEPT;
+};
+
+class _LIBCPP_EXCEPTION_ABI bad_exception
+    : public exception
+{
+public:
+    _LIBCPP_INLINE_VISIBILITY bad_exception() _NOEXCEPT {}
+    virtual ~bad_exception() _NOEXCEPT;
+    virtual const char* what() const _NOEXCEPT;
+};
+
+typedef void (*unexpected_handler)();
+_LIBCPP_FUNC_VIS unexpected_handler set_unexpected(unexpected_handler) _NOEXCEPT;
+_LIBCPP_FUNC_VIS unexpected_handler get_unexpected() _NOEXCEPT;
+_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void unexpected();
+
+typedef void (*terminate_handler)();
+_LIBCPP_FUNC_VIS terminate_handler set_terminate(terminate_handler) _NOEXCEPT;
+_LIBCPP_FUNC_VIS terminate_handler get_terminate() _NOEXCEPT;
+_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void terminate() _NOEXCEPT;
+
+_LIBCPP_FUNC_VIS bool uncaught_exception() _NOEXCEPT;
+_LIBCPP_FUNC_VIS int uncaught_exceptions() _NOEXCEPT;
+
+class _LIBCPP_TYPE_VIS exception_ptr;
+
+_LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
+_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
+
+class _LIBCPP_TYPE_VIS exception_ptr
+{
+    void* __ptr_;
+public:
+    _LIBCPP_INLINE_VISIBILITY exception_ptr() _NOEXCEPT : __ptr_() {}
+    _LIBCPP_INLINE_VISIBILITY exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
+    exception_ptr(const exception_ptr&) _NOEXCEPT;
+    exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;
+    ~exception_ptr() _NOEXCEPT;
+
+    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_EXPLICIT
+        operator bool() const _NOEXCEPT {return __ptr_ != nullptr;}
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
+        {return __x.__ptr_ == __y.__ptr_;}
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
+        {return !(__x == __y);}
+
+    friend _LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
+    friend _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
+};
+
+template<class _Ep>
+exception_ptr
+make_exception_ptr(_Ep __e) _NOEXCEPT
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+        throw __e;
+    }
+    catch (...)
+    {
+        return current_exception();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+}
+
+// nested_exception
+
+class _LIBCPP_EXCEPTION_ABI nested_exception
+{
+    exception_ptr __ptr_;
+public:
+    nested_exception() _NOEXCEPT;
+//     nested_exception(const nested_exception&) noexcept = default;
+//     nested_exception& operator=(const nested_exception&) noexcept = default;
+    virtual ~nested_exception() _NOEXCEPT;
+
+    // access functions
+    _LIBCPP_NORETURN void rethrow_nested() const;
+    _LIBCPP_INLINE_VISIBILITY exception_ptr nested_ptr() const _NOEXCEPT {return __ptr_;}
+};
+
+template <class _Tp>
+struct __nested
+    : public _Tp,
+      public nested_exception
+{
+    _LIBCPP_INLINE_VISIBILITY explicit __nested(const _Tp& __t) : _Tp(__t) {}
+};
+
+template <class _Tp>
+_LIBCPP_NORETURN
+void
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+throw_with_nested(_Tp&& __t, typename enable_if<
+                  is_class<typename remove_reference<_Tp>::type>::value &&
+                  !is_base_of<nested_exception, typename remove_reference<_Tp>::type>::value
+                  && !__libcpp_is_final<typename remove_reference<_Tp>::type>::value
+                                    >::type* = 0)
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+throw_with_nested (_Tp& __t, typename enable_if<
+                  is_class<_Tp>::value && !is_base_of<nested_exception, _Tp>::value
+                                    >::type* = 0)
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    throw __nested<typename remove_reference<_Tp>::type>(_VSTD::forward<_Tp>(__t));
+#endif
+}
+
+template <class _Tp>
+_LIBCPP_NORETURN
+void
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+throw_with_nested(_Tp&& __t, typename enable_if<
+                  !is_class<typename remove_reference<_Tp>::type>::value ||
+                  is_base_of<nested_exception, typename remove_reference<_Tp>::type>::value
+                  || __libcpp_is_final<typename remove_reference<_Tp>::type>::value
+                                    >::type* = 0)
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+throw_with_nested (_Tp& __t, typename enable_if<
+                  !is_class<_Tp>::value || is_base_of<nested_exception, _Tp>::value
+                                    >::type* = 0)
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    throw _VSTD::forward<_Tp>(__t);
+#endif
+}
+
+template <class _Ep>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+rethrow_if_nested(const _Ep& __e, typename enable_if<
+                                   is_polymorphic<_Ep>::value
+                                                   >::type* = 0)
+{
+    const nested_exception* __nep = dynamic_cast<const nested_exception*>(&__e);
+    if (__nep)
+        __nep->rethrow_nested();
+}
+
+template <class _Ep>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+rethrow_if_nested(const _Ep&, typename enable_if<
+                                   !is_polymorphic<_Ep>::value
+                                                   >::type* = 0)
+{
+}
+
+}  // std
+
+#endif  // _LIBCPP_EXCEPTION

diff --git a/libcxx/include/experimental/__config b/libcxx/include/experimental/__config
new file mode 100644
index 0000000..f64a3a9
--- /dev/null
+++ b/libcxx/include/experimental/__config

@@ -0,0 +1,32 @@
+// -*- C++ -*-
+//===--------------------------- __config ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_EXPERIMENTAL_CONFIG
+#define _LIBCPP_EXPERIMENTAL_CONFIG
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#define _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL namespace std { namespace experimental {
+#define _LIBCPP_END_NAMESPACE_EXPERIMENTAL  } }
+#define _VSTD_EXPERIMENTAL std::experimental
+
+#define _LIBCPP_BEGIN_NAMESPACE_LFTS _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL inline namespace fundamentals_v1 {
+#define _LIBCPP_END_NAMESPACE_LFTS  } } }
+#define _VSTD_LFTS _VSTD_EXPERIMENTAL::fundamentals_v1
+
+#define _LIBCPP_BEGIN_NAMESPACE_CHRONO_LFTS _LIBCPP_BEGIN_NAMESPACE_STD        \
+  namespace chrono { namespace experimental { inline namespace fundamentals_v1 {
+#define _LIBCPP_END_NAMESPACE_CHRONO_LFTS _LIBCPP_END_NAMESPACE_STD } } }
+
+#endif

diff --git a/libcxx/include/experimental/algorithm b/libcxx/include/experimental/algorithm
new file mode 100644
index 0000000..ffaa793
--- /dev/null
+++ b/libcxx/include/experimental/algorithm

@@ -0,0 +1,120 @@
+// -*- C++ -*-
+//===-------------------------- algorithm ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_EXPERIMENTAL_ALGORITHM
+#define _LIBCPP_EXPERIMENTAL_ALGORITHM
+
+/*
+   experimental/algorithm synopsis
+
+#include <algorithm>
+
+namespace std {
+namespace experimental {
+inline namespace fundamentals_v1 {
+
+template <class ForwardIterator, class Searcher>
+ForwardIterator search(ForwardIterator first, ForwardIterator last,
+                       const Searcher &searcher);
+template <class PopulationIterator, class SampleIterator, class Distance,
+          class UniformRandomNumberGenerator>
+SampleIterator sample(PopulationIterator first, PopulationIterator last,
+                      SampleIterator out, Distance n,
+                      UniformRandomNumberGenerator &&g);
+
+} // namespace fundamentals_v1
+} // namespace experimental
+} // namespace std
+
+*/
+
+#include <experimental/__config>
+#include <algorithm>
+#include <type_traits>
+
+#include <__undef_min_max>
+
+#include <__debug>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_LFTS
+
+
+template <class _ForwardIterator, class _Searcher>
+_LIBCPP_INLINE_VISIBILITY
+_ForwardIterator search(_ForwardIterator __f, _ForwardIterator __l, const _Searcher &__s)
+{ return __s(__f, __l); }
+
+
+template <class _PopulationIterator, class _SampleIterator, class _Distance,
+          class _UniformRandomNumberGenerator>
+_LIBCPP_INLINE_VISIBILITY
+_SampleIterator __sample(_PopulationIterator __first,
+                         _PopulationIterator __last, _SampleIterator __out,
+                         _Distance __n,
+                         _UniformRandomNumberGenerator &&__g,
+                         input_iterator_tag) {
+
+  _Distance __k = 0;
+  for (; __first != __last && __k < __n; ++__first, (void)++__k)
+    __out[__k] = *__first;
+  _Distance __sz = __k;
+  for (; __first != __last; ++__first, (void)++__k) {
+    _Distance __r = _VSTD::uniform_int_distribution<_Distance>(0, __k)(__g);
+    if (__r < __sz)
+      __out[__r] = *__first;
+  }
+  return __out + _VSTD::min(__n, __k);
+}
+
+template <class _PopulationIterator, class _SampleIterator, class _Distance,
+          class _UniformRandomNumberGenerator>
+_LIBCPP_INLINE_VISIBILITY
+_SampleIterator __sample(_PopulationIterator __first,
+                         _PopulationIterator __last, _SampleIterator __out,
+                         _Distance __n,
+                         _UniformRandomNumberGenerator &&__g,
+                         forward_iterator_tag) {
+  _Distance __unsampled_sz = _VSTD::distance(__first, __last);
+  for (__n = _VSTD::min(__n, __unsampled_sz); __n != 0; ++__first) {
+    _Distance __r =
+        _VSTD::uniform_int_distribution<_Distance>(0, --__unsampled_sz)(__g);
+    if (__r < __n) {
+      *__out++ = *__first;
+      --__n;
+    }
+  }
+  return __out;
+}
+
+template <class _PopulationIterator, class _SampleIterator, class _Distance,
+          class _UniformRandomNumberGenerator>
+_LIBCPP_INLINE_VISIBILITY
+_SampleIterator sample(_PopulationIterator __first,
+                         _PopulationIterator __last, _SampleIterator __out,
+                         _Distance __n, _UniformRandomNumberGenerator &&__g) {
+  typedef typename iterator_traits<_PopulationIterator>::iterator_category
+        _PopCategory;
+  typedef typename iterator_traits<_PopulationIterator>::difference_type
+        _Difference;
+  typedef typename common_type<_Distance, _Difference>::type _CommonType;
+  _LIBCPP_ASSERT(__n >= 0, "N must be a positive number.");
+  return _VSTD_LFTS::__sample(
+      __first, __last, __out, _CommonType(__n),
+      _VSTD::forward<_UniformRandomNumberGenerator>(__g),
+      _PopCategory());
+}
+
+_LIBCPP_END_NAMESPACE_LFTS
+
+#endif /* _LIBCPP_EXPERIMENTAL_ALGORITHM */

diff --git a/libcxx/include/experimental/any b/libcxx/include/experimental/any
new file mode 100644
index 0000000..a38397a
--- /dev/null
+++ b/libcxx/include/experimental/any

@@ -0,0 +1,592 @@
+// -*- C++ -*-
+//===------------------------------ any -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_EXPERIMENTAL_ANY
+#define _LIBCPP_EXPERIMENTAL_ANY
+
+/*
+   experimental/any synopsis
+
+namespace std {
+namespace experimental {
+inline namespace fundamentals_v1 {
+
+  class bad_any_cast : public bad_cast
+  {
+  public:
+    virtual const char* what() const noexcept;
+  };
+
+  class any
+  {
+  public:
+
+    // 6.3.1 any construct/destruct
+    any() noexcept;
+
+    any(const any& other);
+    any(any&& other) noexcept;
+
+    template <class ValueType>
+      any(ValueType&& value);
+
+    ~any();
+
+    // 6.3.2 any assignments
+    any& operator=(const any& rhs);
+    any& operator=(any&& rhs) noexcept;
+
+    template <class ValueType>
+      any& operator=(ValueType&& rhs);
+
+    // 6.3.3 any modifiers
+    void clear() noexcept;
+    void swap(any& rhs) noexcept;
+
+    // 6.3.4 any observers
+    bool empty() const noexcept;
+    const type_info& type() const noexcept;
+  };
+
+   // 6.4 Non-member functions
+  void swap(any& x, any& y) noexcept;
+
+  template<class ValueType>
+    ValueType any_cast(const any& operand);
+  template<class ValueType>
+    ValueType any_cast(any& operand);
+  template<class ValueType>
+    ValueType any_cast(any&& operand);
+
+  template<class ValueType>
+    const ValueType* any_cast(const any* operand) noexcept;
+  template<class ValueType>
+    ValueType* any_cast(any* operand) noexcept;
+
+} // namespace fundamentals_v1
+} // namespace experimental
+} // namespace std
+
+*/
+
+#include <experimental/__config>
+#include <memory>
+#include <new>
+#include <typeinfo>
+#include <type_traits>
+#include <cstdlib>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_LFTS
+
+class _LIBCPP_EXCEPTION_ABI bad_any_cast : public bad_cast
+{
+public:
+     //TODO(EricWF) Enable or delete these.
+    //bad_any_cast() _NOEXCEPT;
+    //virtual ~bad_any_cast() _NOEXCEPT;
+    virtual const char* what() const _NOEXCEPT;
+};
+
+#if _LIBCPP_STD_VER > 11                                            // C++ > 11
+
+_LIBCPP_NORETURN _LIBCPP_INLINE_VISIBILITY
+inline void __throw_bad_any_cast()
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    throw bad_any_cast();
+#else
+    _VSTD::abort();
+#endif
+}
+
+// Forward declarations
+class any;
+
+template <class _ValueType>
+typename add_pointer<typename add_const<_ValueType>::type>::type
+any_cast(any const *) _NOEXCEPT;
+
+template <class _ValueType>
+typename add_pointer<_ValueType>::type
+any_cast(any *) _NOEXCEPT;
+
+namespace __any_imp
+{
+  typedef typename aligned_storage<3*sizeof(void*), alignment_of<void*>::value>::type
+    _Buffer;
+
+  template <class _Tp>
+  struct _IsSmallObject
+    : public integral_constant<bool
+        , sizeof(_Tp) <= sizeof(_Buffer)
+          && alignment_of<_Buffer>::value
+             % alignment_of<_Tp>::value == 0
+          && is_nothrow_move_constructible<_Tp>::value
+        >
+  {};
+
+  enum class _Action
+  {
+    _Destroy,
+    _Copy,
+    _Move,
+    _Get,
+    _TypeInfo
+  };
+
+  template <class _Tp>
+  struct _SmallHandler;
+
+  template <class _Tp>
+  struct _LargeHandler;
+
+  template <class _Tp>
+  using _Handler = typename conditional<_IsSmallObject<_Tp>::value
+                                      , _SmallHandler<_Tp>
+                                      , _LargeHandler<_Tp>
+                                    >::type;
+  template <class _ValueType>
+  using _EnableIfNotAny = typename
+    enable_if<
+      !is_same<typename decay<_ValueType>::type, any>::value
+    >::type;
+
+} // namespace __any_imp
+
+class any
+{
+public:
+  // 6.3.1 any construct/destruct
+  _LIBCPP_INLINE_VISIBILITY
+  any() _NOEXCEPT : __h(nullptr) {}
+
+  _LIBCPP_INLINE_VISIBILITY
+  any(any const & __other) : __h(nullptr)
+  {
+    if (__other.__h) __other.__call(_Action::_Copy, this);
+  }
+
+  _LIBCPP_INLINE_VISIBILITY
+  any(any && __other) _NOEXCEPT : __h(nullptr)
+  {
+    if (__other.__h) __other.__call(_Action::_Move, this);
+  }
+
+  template <
+      class _ValueType
+    , class = __any_imp::_EnableIfNotAny<_ValueType>
+    >
+  any(_ValueType && __value);
+
+  _LIBCPP_INLINE_VISIBILITY
+  ~any()
+  {
+    this->clear();
+  }
+
+  // 6.3.2 any assignments
+  _LIBCPP_INLINE_VISIBILITY
+  any & operator=(any const & __rhs)
+  {
+    any(__rhs).swap(*this);
+    return *this;
+  }
+
+  _LIBCPP_INLINE_VISIBILITY
+  any & operator=(any && __rhs) _NOEXCEPT
+  {
+    any(_VSTD::move(__rhs)).swap(*this);
+    return *this;
+  }
+
+  template <
+      class _ValueType
+    , class = __any_imp::_EnableIfNotAny<_ValueType>
+    >
+  any & operator=(_ValueType && __rhs);
+
+  // 6.3.3 any modifiers
+  _LIBCPP_INLINE_VISIBILITY
+  void clear() _NOEXCEPT
+  {
+    if (__h) this->__call(_Action::_Destroy);
+  }
+
+  void swap(any & __rhs) _NOEXCEPT;
+
+  // 6.3.4 any observers
+  _LIBCPP_INLINE_VISIBILITY
+  bool empty() const _NOEXCEPT
+  {
+    return __h == nullptr;
+  }
+
+#if !defined(_LIBCPP_NO_RTTI)
+  _LIBCPP_INLINE_VISIBILITY
+  const type_info & type() const _NOEXCEPT
+  {
+    if (__h) {
+        return *static_cast<type_info const *>(this->__call(_Action::_TypeInfo));
+    } else {
+        return typeid(void);
+    }
+  }
+#endif
+
+private:
+    typedef __any_imp::_Action _Action;
+
+    typedef void* (*_HandleFuncPtr)(_Action, any const *, any *, const type_info *);
+
+    union _Storage
+    {
+        void *  __ptr;
+        __any_imp::_Buffer __buf;
+    };
+
+    _LIBCPP_ALWAYS_INLINE
+    void * __call(_Action __a, any * __other = nullptr,
+                  type_info const * __info = nullptr) const
+    {
+        return __h(__a, this, __other, __info);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    void * __call(_Action __a, any * __other = nullptr,
+                  type_info const * __info = nullptr)
+    {
+        return __h(__a, this, __other, __info);
+    }
+
+    template <class>
+    friend struct __any_imp::_SmallHandler;
+    template <class>
+    friend struct __any_imp::_LargeHandler;
+
+    template <class _ValueType>
+    friend typename add_pointer<typename add_const<_ValueType>::type>::type
+    any_cast(any const *) _NOEXCEPT;
+
+    template <class _ValueType>
+    friend typename add_pointer<_ValueType>::type
+    any_cast(any *) _NOEXCEPT;
+
+    _HandleFuncPtr __h;
+    _Storage __s;
+};
+
+namespace __any_imp
+{
+
+  template <class _Tp>
+  struct _LIBCPP_TYPE_VIS_ONLY _SmallHandler
+  {
+     _LIBCPP_INLINE_VISIBILITY
+     static void* __handle(_Action __act, any const * __this, any * __other,
+                           type_info const * __info)
+     {
+        switch (__act)
+        {
+        case _Action::_Destroy:
+          __destroy(const_cast<any &>(*__this));
+          return nullptr;
+        case _Action::_Copy:
+            __copy(*__this, *__other);
+            return nullptr;
+        case _Action::_Move:
+          __move(const_cast<any &>(*__this), *__other);
+          return nullptr;
+        case _Action::_Get:
+            return __get(const_cast<any &>(*__this), __info);
+        case _Action::_TypeInfo:
+          return __type_info();
+        }
+    }
+
+    template <class _Up>
+    _LIBCPP_INLINE_VISIBILITY
+    static void __create(any & __dest, _Up && __v)
+    {
+        ::new (static_cast<void*>(&__dest.__s.__buf)) _Tp(_VSTD::forward<_Up>(__v));
+        __dest.__h = &_SmallHandler::__handle;
+    }
+
+  private:
+    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
+    static void __destroy(any & __this)
+    {
+        _Tp & __value = *static_cast<_Tp *>(static_cast<void*>(&__this.__s.__buf));
+        __value.~_Tp();
+        __this.__h = nullptr;
+    }
+
+    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
+    static void __copy(any const & __this, any & __dest)
+    {
+        _SmallHandler::__create(__dest, *static_cast<_Tp const *>(
+            static_cast<void const *>(&__this.__s.__buf)));
+    }
+
+    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
+    static void __move(any & __this, any & __dest)
+    {
+        _SmallHandler::__create(__dest, _VSTD::move(
+            *static_cast<_Tp*>(static_cast<void*>(&__this.__s.__buf))));
+        __destroy(__this);
+    }
+
+    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
+    static void* __get(any & __this, type_info const * __info)
+    {
+#if !defined(_LIBCPP_NO_RTTI)
+        if (typeid(_Tp) == *__info) {
+            return static_cast<void*>(&__this.__s.__buf);
+        }
+        return nullptr;
+#else
+        return static_cast<void*>(&__this.__s.__buf);
+#endif
+    }
+
+    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
+    static void* __type_info()
+    {
+#if !defined(_LIBCPP_NO_RTTI)
+        return const_cast<void*>(static_cast<void const *>(&typeid(_Tp)));
+#else
+        return nullptr;
+#endif
+    }
+  };
+
+  template <class _Tp>
+  struct _LIBCPP_TYPE_VIS_ONLY _LargeHandler
+  {
+    _LIBCPP_INLINE_VISIBILITY
+    static void* __handle(_Action __act, any const * __this, any * __other,
+                          type_info const * __info)
+    {
+        switch (__act)
+        {
+        case _Action::_Destroy:
+          __destroy(const_cast<any &>(*__this));
+          return nullptr;
+        case _Action::_Copy:
+          __copy(*__this, *__other);
+          return nullptr;
+        case _Action::_Move:
+          __move(const_cast<any &>(*__this), *__other);
+          return nullptr;
+        case _Action::_Get:
+            return __get(const_cast<any &>(*__this), __info);
+        case _Action::_TypeInfo:
+          return __type_info();
+        }
+    }
+
+    template <class _Up>
+    _LIBCPP_INLINE_VISIBILITY
+    static void __create(any & __dest, _Up && __v)
+    {
+        typedef allocator<_Tp> _Alloc;
+        typedef __allocator_destructor<_Alloc> _Dp;
+        _Alloc __a;
+        unique_ptr<_Tp, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+        ::new ((void*)__hold.get()) _Tp(_VSTD::forward<_Up>(__v));
+        __dest.__s.__ptr = __hold.release();
+        __dest.__h = &_LargeHandler::__handle;
+    }
+
+  private:
+
+    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
+    static void __destroy(any & __this)
+    {
+        delete static_cast<_Tp*>(__this.__s.__ptr);
+        __this.__h = nullptr;
+    }
+
+    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
+    static void __copy(any const & __this, any & __dest)
+    {
+        _LargeHandler::__create(__dest, *static_cast<_Tp const *>(__this.__s.__ptr));
+    }
+
+    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
+    static void __move(any & __this, any & __dest)
+    {
+      __dest.__s.__ptr = __this.__s.__ptr;
+      __dest.__h = &_LargeHandler::__handle;
+      __this.__h = nullptr;
+    }
+
+    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
+    static void* __get(any & __this, type_info const * __info)
+    {
+#if !defined(_LIBCPP_NO_RTTI)
+        if (typeid(_Tp) == *__info) {
+            return static_cast<void*>(__this.__s.__ptr);
+        }
+        return nullptr;
+#else
+        return static_cast<void*>(__this.__s.__ptr);
+#endif
+    }
+
+    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
+    static void* __type_info()
+    {
+#if !defined(_LIBCPP_NO_RTTI)
+        return const_cast<void*>(static_cast<void const *>(&typeid(_Tp)));
+#else
+        return nullptr;
+#endif
+    }
+  };
+
+} // namespace __any_imp
+
+
+template <class _ValueType, class>
+_LIBCPP_INLINE_VISIBILITY
+any::any(_ValueType && __v) : __h(nullptr)
+{
+  typedef typename decay<_ValueType>::type _Tp;
+  static_assert(is_copy_constructible<_Tp>::value,
+                "_ValueType must be CopyConstructible.");
+  typedef __any_imp::_Handler<_Tp> _HandlerType;
+  _HandlerType::__create(*this, _VSTD::forward<_ValueType>(__v));
+}
+
+template <class _ValueType, class>
+_LIBCPP_INLINE_VISIBILITY
+any & any::operator=(_ValueType && __v)
+{
+  typedef typename decay<_ValueType>::type _Tp;
+  static_assert(is_copy_constructible<_Tp>::value,
+                "_ValueType must be CopyConstructible.");
+  any(_VSTD::forward<_ValueType>(__v)).swap(*this);
+  return *this;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+void any::swap(any & __rhs) _NOEXCEPT
+{
+    if (__h && __rhs.__h) {
+        any __tmp;
+        __rhs.__call(_Action::_Move, &__tmp);
+        this->__call(_Action::_Move, &__rhs);
+        __tmp.__call(_Action::_Move, this);
+    }
+    else if (__h) {
+        this->__call(_Action::_Move, &__rhs);
+    }
+    else if (__rhs.__h) {
+        __rhs.__call(_Action::_Move, this);
+    }
+}
+
+// 6.4 Non-member functions
+
+inline _LIBCPP_INLINE_VISIBILITY
+void swap(any & __lhs, any & __rhs) _NOEXCEPT
+{
+    __lhs.swap(__rhs);
+}
+
+template <class _ValueType>
+_LIBCPP_INLINE_VISIBILITY
+_ValueType any_cast(any const & __v)
+{
+    static_assert(
+        is_reference<_ValueType>::value
+        || is_copy_constructible<_ValueType>::value,
+        "_ValueType is required to be a reference or a CopyConstructible type.");
+    typedef typename add_const<typename remove_reference<_ValueType>::type>::type
+            _Tp;
+    _Tp * __tmp = any_cast<_Tp>(&__v);
+    if (__tmp == nullptr)
+        __throw_bad_any_cast();
+    return *__tmp;
+}
+
+template <class _ValueType>
+_LIBCPP_INLINE_VISIBILITY
+_ValueType any_cast(any & __v)
+{
+    static_assert(
+        is_reference<_ValueType>::value
+        || is_copy_constructible<_ValueType>::value,
+        "_ValueType is required to be a reference or a CopyConstructible type.");
+    typedef typename remove_reference<_ValueType>::type _Tp;
+    _Tp * __tmp = any_cast<_Tp>(&__v);
+    if (__tmp == nullptr)
+        __throw_bad_any_cast();
+    return *__tmp;
+}
+
+template <class _ValueType>
+_LIBCPP_INLINE_VISIBILITY
+_ValueType any_cast(any && __v)
+{
+    static_assert(
+        is_reference<_ValueType>::value
+        || is_copy_constructible<_ValueType>::value,
+        "_ValueType is required to be a reference or a CopyConstructible type.");
+    typedef typename remove_reference<_ValueType>::type _Tp;
+    _Tp * __tmp = any_cast<_Tp>(&__v);
+    if (__tmp == nullptr)
+        __throw_bad_any_cast();
+    return *__tmp;
+}
+
+template <class _ValueType>
+inline _LIBCPP_INLINE_VISIBILITY
+typename add_pointer<typename add_const<_ValueType>::type>::type
+any_cast(any const * __any) _NOEXCEPT
+{
+    static_assert(!is_reference<_ValueType>::value,
+                  "_ValueType may not be a reference.");
+    return any_cast<_ValueType>(const_cast<any *>(__any));
+}
+
+template <class _ValueType>
+_LIBCPP_INLINE_VISIBILITY
+typename add_pointer<_ValueType>::type
+any_cast(any * __any) _NOEXCEPT
+{
+    using __any_imp::_Action;
+    static_assert(!is_reference<_ValueType>::value,
+                  "_ValueType may not be a reference.");
+    typedef typename add_pointer<_ValueType>::type _ReturnType;
+    if (__any && __any->__h) {
+
+        return static_cast<_ReturnType>(
+            __any->__call(_Action::_Get, nullptr,
+#if !defined(_LIBCPP_NO_RTTI)
+                &typeid(_ValueType)
+#else
+                nullptr
+#endif
+        ));
+
+    }
+    return nullptr;
+}
+
+#endif // _LIBCPP_STD_VER > 11
+
+_LIBCPP_END_NAMESPACE_LFTS
+
+#endif // _LIBCPP_EXPERIMENTAL_ANY

diff --git a/libcxx/include/experimental/chrono b/libcxx/include/experimental/chrono
new file mode 100644
index 0000000..ca9e5f8
--- /dev/null
+++ b/libcxx/include/experimental/chrono

@@ -0,0 +1,59 @@
+// -*- C++ -*-
+//===------------------------------ chrono ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_EXPERIMENTAL_CHRONO
+#define _LIBCPP_EXPERIMENTAL_CHRONO
+
+/**
+    experimental/chrono synopsis
+
+// C++1y
+
+#include <chrono>
+
+namespace std {
+namespace chrono {
+namespace experimental {
+inline namespace fundamentals_v1 {
+
+  // See C++14 20.12.4, customization traits
+  template <class Rep> constexpr bool treat_as_floating_point_v
+    = treat_as_floating_point<Rep>::value;
+
+} // namespace fundamentals_v1
+} // namespace experimental
+} // namespace chrono
+} // namespace std
+
+ */
+
+#include <experimental/__config>
+#include <chrono>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 11
+
+_LIBCPP_BEGIN_NAMESPACE_CHRONO_LFTS
+
+#ifndef _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
+
+template <class _Rep> _LIBCPP_CONSTEXPR bool treat_as_floating_point_v
+    = treat_as_floating_point<_Rep>::value;
+
+#endif /* _LIBCPP_HAS_NO_VARIABLE_TEMPLATES */
+
+_LIBCPP_END_NAMESPACE_CHRONO_LFTS
+
+#endif /* _LIBCPP_STD_VER > 11 */
+
+#endif /* _LIBCPP_EXPERIMENTAL_CHRONO */

diff --git a/libcxx/include/experimental/dynarray b/libcxx/include/experimental/dynarray
new file mode 100644
index 0000000..a025862
--- /dev/null
+++ b/libcxx/include/experimental/dynarray

@@ -0,0 +1,316 @@
+// -*- C++ -*-
+//===-------------------------- dynarray ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_DYNARRAY
+#define _LIBCPP_DYNARRAY
+
+#include <__config>
+#if _LIBCPP_STD_VER > 11
+
+/*
+    dynarray synopsis
+
+namespace std { namespace experimental {
+
+template< typename T >
+class dynarray
+{
+    // types:
+    typedef       T                               value_type;
+    typedef       T&                              reference;
+    typedef const T&                              const_reference;
+    typedef       T*                              pointer;
+    typedef const T*                              const_pointer;
+    typedef       implementation-defined          iterator;
+    typedef       implementation-defined          const_iterator;
+    typedef reverse_iterator<iterator>            reverse_iterator;
+    typedef reverse_iterator<const_iterator>      const_reverse_iterator;
+    typedef size_t                                size_type;
+    typedef ptrdiff_t                             difference_type;
+
+public:
+    // construct/copy/destroy:
+    explicit dynarray(size_type c);
+    dynarray(size_type c, const T& v);
+    dynarray(const dynarray& d);
+    dynarray(initializer_list<T>);
+
+    template <class Alloc>
+      dynarray(allocator_arg_t, const Alloc& a, size_type c, const Alloc& alloc);
+    template <class Alloc>
+      dynarray(allocator_arg_t, const Alloc& a, size_type c, const T& v, const Alloc& alloc);
+    template <class Alloc>
+      dynarray(allocator_arg_t, const Alloc& a, const dynarray& d, const Alloc& alloc);
+    template <class Alloc>
+      dynarray(allocator_arg_t, const Alloc& a, initializer_list<T>, const Alloc& alloc);
+    dynarray& operator=(const dynarray&) = delete;
+    ~dynarray();
+
+    // iterators:
+    iterator       begin()        noexcept;
+    const_iterator begin()  const noexcept;
+    const_iterator cbegin() const noexcept;
+    iterator       end()          noexcept;
+    const_iterator end()    const noexcept;
+    const_iterator cend()   const noexcept;
+
+    reverse_iterator       rbegin()        noexcept;
+    const_reverse_iterator rbegin()  const noexcept;
+    const_reverse_iterator crbegin() const noexcept;
+    reverse_iterator       rend()          noexcept;
+    const_reverse_iterator rend()    const noexcept;
+    const_reverse_iterator crend()   const noexcept;
+
+    // capacity:
+    size_type size()     const noexcept;
+    size_type max_size() const noexcept;
+    bool      empty()    const noexcept;
+
+    // element access:
+    reference       operator[](size_type n);
+    const_reference operator[](size_type n) const;
+
+    reference       front();
+    const_reference front() const;
+    reference       back();
+    const_reference back()  const;
+
+    const_reference at(size_type n) const;
+    reference       at(size_type n);
+
+    // data access:
+    T*       data()       noexcept;
+    const T* data() const noexcept;
+
+    // mutating member functions:
+    void fill(const T& v);
+};
+
+}}  // std::experimental
+
+*/
+
+#include <__functional_base>
+#include <iterator>
+#include <stdexcept>
+#include <initializer_list>
+#include <new>
+#include <algorithm>
+
+#include <__undef___deallocate>
+
+#if defined(_LIBCPP_NO_EXCEPTIONS)
+    #include <cassert>
+#endif
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+namespace std { namespace experimental { inline namespace __array_extensions_v1 {
+
+template <class _Tp>
+struct _LIBCPP_TYPE_VIS_ONLY dynarray
+{
+public:
+    // types:
+    typedef dynarray __self;
+    typedef _Tp                                   value_type;
+    typedef value_type&                           reference;
+    typedef const value_type&                     const_reference;
+    typedef value_type*                           iterator;
+    typedef const value_type*                     const_iterator;
+    typedef value_type*                           pointer;
+    typedef const value_type*                     const_pointer;
+    typedef size_t                                size_type;
+    typedef ptrdiff_t                             difference_type;
+    typedef std::reverse_iterator<iterator>       reverse_iterator;
+    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
+
+private:
+    size_t                  __size_;
+    value_type *            __base_;
+    _LIBCPP_ALWAYS_INLINE dynarray () noexcept : __base_(nullptr), __size_(0) {}
+    
+    static inline _LIBCPP_INLINE_VISIBILITY value_type* __allocate ( size_t count )
+    {
+        if ( numeric_limits<size_t>::max() / sizeof (value_type) <= count )
+        {
+#ifndef _LIBCPP_NO_EXCEPTIONS
+            throw bad_array_length();
+#else
+            assert(!"dynarray::allocation");
+#endif
+        }
+        return static_cast<value_type *> (_VSTD::__allocate (sizeof(value_type) * count));
+    }
+
+    static inline _LIBCPP_INLINE_VISIBILITY void __deallocate ( value_type* __ptr ) noexcept
+    {
+        _VSTD::__deallocate (static_cast<void *> (__ptr));
+    }
+
+public:
+
+    explicit dynarray(size_type __c);
+    dynarray(size_type __c, const value_type& __v);
+    dynarray(const dynarray& __d);
+    dynarray(initializer_list<value_type>);
+
+//  We're not implementing these right now.
+//  Updated with the resolution of LWG issue #2255
+//     template <typename _Alloc>
+//       dynarray(allocator_arg_t, const _Alloc& __alloc, size_type __c);
+//     template <typename _Alloc>
+//       dynarray(allocator_arg_t, const _Alloc& __alloc, size_type __c, const value_type& __v);
+//     template <typename _Alloc>
+//       dynarray(allocator_arg_t, const _Alloc& __alloc, const dynarray& __d);
+//     template <typename _Alloc>
+//       dynarray(allocator_arg_t, const _Alloc& __alloc, initializer_list<value_type>);
+
+    dynarray& operator=(const dynarray&) = delete;
+    ~dynarray();
+
+    // iterators:
+    inline _LIBCPP_INLINE_VISIBILITY iterator       begin()        noexcept { return iterator(data()); }
+    inline _LIBCPP_INLINE_VISIBILITY const_iterator begin()  const noexcept { return const_iterator(data()); }
+    inline _LIBCPP_INLINE_VISIBILITY const_iterator cbegin() const noexcept { return const_iterator(data()); }
+    inline _LIBCPP_INLINE_VISIBILITY iterator       end()          noexcept { return iterator(data() + __size_); }
+    inline _LIBCPP_INLINE_VISIBILITY const_iterator end()    const noexcept { return const_iterator(data() + __size_); }
+    inline _LIBCPP_INLINE_VISIBILITY const_iterator cend()   const noexcept { return const_iterator(data() + __size_); }
+
+    inline _LIBCPP_INLINE_VISIBILITY reverse_iterator       rbegin()        noexcept { return reverse_iterator(end()); }
+    inline _LIBCPP_INLINE_VISIBILITY const_reverse_iterator rbegin()  const noexcept { return const_reverse_iterator(end()); }
+    inline _LIBCPP_INLINE_VISIBILITY const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator(end()); }
+    inline _LIBCPP_INLINE_VISIBILITY reverse_iterator       rend()          noexcept { return reverse_iterator(begin()); }
+    inline _LIBCPP_INLINE_VISIBILITY const_reverse_iterator rend()    const noexcept { return const_reverse_iterator(begin()); }
+    inline _LIBCPP_INLINE_VISIBILITY const_reverse_iterator crend()   const noexcept { return const_reverse_iterator(begin()); }
+
+    // capacity:
+    inline _LIBCPP_INLINE_VISIBILITY size_type size()     const noexcept { return __size_; }
+    inline _LIBCPP_INLINE_VISIBILITY size_type max_size() const noexcept { return __size_; }
+    inline _LIBCPP_INLINE_VISIBILITY bool      empty()    const noexcept { return __size_ == 0; }
+
+    // element access:
+    inline _LIBCPP_INLINE_VISIBILITY reference       operator[](size_type __n)       { return data()[__n]; }
+    inline _LIBCPP_INLINE_VISIBILITY const_reference operator[](size_type __n) const { return data()[__n]; }
+
+    inline _LIBCPP_INLINE_VISIBILITY reference       front()       { return data()[0]; }
+    inline _LIBCPP_INLINE_VISIBILITY const_reference front() const { return data()[0]; }
+    inline _LIBCPP_INLINE_VISIBILITY reference       back()        { return data()[__size_-1]; }
+    inline _LIBCPP_INLINE_VISIBILITY const_reference back()  const { return data()[__size_-1]; }
+
+    inline _LIBCPP_INLINE_VISIBILITY const_reference at(size_type __n) const;
+    inline _LIBCPP_INLINE_VISIBILITY reference       at(size_type __n);
+
+    // data access:
+    inline _LIBCPP_INLINE_VISIBILITY _Tp*       data()       noexcept { return __base_; }
+    inline _LIBCPP_INLINE_VISIBILITY const _Tp* data() const noexcept { return __base_; }
+
+    // mutating member functions:
+    inline _LIBCPP_INLINE_VISIBILITY void fill(const value_type& __v) { fill_n(begin(), __size_, __v); }
+};
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+dynarray<_Tp>::dynarray(size_type __c) : dynarray ()
+{
+    __base_ = __allocate (__c);
+    value_type *__data = data ();
+    for ( __size_ = 0; __size_ < __c; ++__size_, ++__data )
+        ::new (__data) value_type;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+dynarray<_Tp>::dynarray(size_type __c, const value_type& __v) : dynarray ()
+{
+    __base_ = __allocate (__c);
+    value_type *__data = data ();
+    for ( __size_ = 0; __size_ < __c; ++__size_, ++__data )
+        ::new (__data) value_type (__v);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+dynarray<_Tp>::dynarray(initializer_list<value_type> __il) : dynarray ()
+{
+    size_t sz = __il.size();
+    __base_ = __allocate (sz);
+    value_type *__data = data ();
+    auto src = __il.begin();
+    for ( __size_ = 0; __size_ < sz; ++__size_, ++__data, ++src )
+        ::new (__data) value_type (*src);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+dynarray<_Tp>::dynarray(const dynarray& __d) : dynarray ()
+{
+    size_t sz = __d.size();
+    __base_ = __allocate (sz);
+    value_type *__data = data ();
+    auto src = __d.begin();
+    for ( __size_ = 0; __size_ < sz; ++__size_, ++__data, ++src )
+        ::new (__data) value_type (*src);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+dynarray<_Tp>::~dynarray()
+{ 
+    value_type *__data = data () + __size_;
+    for ( size_t i = 0; i < __size_; ++i )
+        (--__data)->value_type::~value_type();
+    __deallocate ( __base_ );
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename dynarray<_Tp>::reference
+dynarray<_Tp>::at(size_type __n)
+{
+    if (__n >= __size_)
+    {
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        throw out_of_range("dynarray::at");
+#else
+        assert(!"dynarray::at out_of_range");
+#endif
+    }
+    return data()[__n];
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename dynarray<_Tp>::const_reference
+dynarray<_Tp>::at(size_type __n) const
+{
+    if (__n >= __size_)
+    {
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        throw out_of_range("dynarray::at");
+#else
+        assert(!"dynarray::at out_of_range");
+#endif
+    }
+    return data()[__n];
+}
+
+}}}
+
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+template <class _Tp, class _Alloc>
+struct _LIBCPP_TYPE_VIS_ONLY uses_allocator<std::experimental::dynarray<_Tp>, _Alloc> : true_type {};
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // if _LIBCPP_STD_VER > 11 
+#endif  // _LIBCPP_DYNARRAY

diff --git a/libcxx/include/experimental/functional b/libcxx/include/experimental/functional
new file mode 100644
index 0000000..f5a905f
--- /dev/null
+++ b/libcxx/include/experimental/functional

@@ -0,0 +1,133 @@
+// -*- C++ -*-
+//===-------------------------- functional --------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_EXPERIMENTAL_FUNCTIONAL
+#define _LIBCPP_EXPERIMENTAL_FUNCTIONAL
+
+/*
+   experimental/functional synopsis
+
+#include <algorithm>
+
+namespace std {
+namespace experimental {
+inline namespace fundamentals_v1 {
+
+    // See C++14 §20.9.9, Function object binders
+    template <class T> constexpr bool is_bind_expression_v
+      = is_bind_expression<T>::value;
+    template <class T> constexpr int is_placeholder_v
+      = is_placeholder<T>::value;
+
+    // 4.2, Class template function
+    template<class> class function; // undefined
+    template<class R, class... ArgTypes> class function<R(ArgTypes...)>;
+
+    template<class R, class... ArgTypes>
+    void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&);
+
+    template<class R, class... ArgTypes>
+    bool operator==(const function<R(ArgTypes...)>&, nullptr_t) noexcept;
+    template<class R, class... ArgTypes>
+    bool operator==(nullptr_t, const function<R(ArgTypes...)>&) noexcept;
+    template<class R, class... ArgTypes>
+    bool operator!=(const function<R(ArgTypes...)>&, nullptr_t) noexcept;
+    template<class R, class... ArgTypes>
+    bool operator!=(nullptr_t, const function<R(ArgTypes...)>&) noexcept;
+
+    // 4.3, Searchers
+    template<class ForwardIterator, class BinaryPredicate = equal_to<>>
+      class default_searcher;
+
+    template<class RandomAccessIterator,
+             class Hash = hash<typename iterator_traits<RandomAccessIterator>::value_type>,
+             class BinaryPredicate = equal_to<>>
+      class boyer_moore_searcher;
+
+    template<class RandomAccessIterator,
+             class Hash = hash<typename iterator_traits<RandomAccessIterator>::value_type>,
+             class BinaryPredicate = equal_to<>>
+      class boyer_moore_horspool_searcher;
+
+    template<class ForwardIterator, class BinaryPredicate = equal_to<>>
+    default_searcher<ForwardIterator, BinaryPredicate>
+    make_default_searcher(ForwardIterator pat_first, ForwardIterator pat_last,
+                          BinaryPredicate pred = BinaryPredicate());
+
+    template<class RandomAccessIterator,
+             class Hash = hash<typename iterator_traits<RandomAccessIterator>::value_type>,
+             class BinaryPredicate = equal_to<>>
+    boyer_moore_searcher<RandomAccessIterator, Hash, BinaryPredicate>
+    make_boyer_moore_searcher(
+        RandomAccessIterator pat_first, RandomAccessIterator pat_last,
+        Hash hf = Hash(), BinaryPredicate pred = BinaryPredicate());
+
+    template<class RandomAccessIterator,
+             class Hash = hash<typename iterator_traits<RandomAccessIterator>::value_type>,
+             class BinaryPredicate = equal_to<>>
+    boyer_moore_horspool_searcher<RandomAccessIterator, Hash, BinaryPredicate>
+    make_boyer_moore_horspool_searcher(
+        RandomAccessIterator pat_first, RandomAccessIterator pat_last,
+        Hash hf = Hash(), BinaryPredicate pred = BinaryPredicate());
+
+  } // namespace fundamentals_v1
+  } // namespace experimental
+
+  template<class R, class... ArgTypes, class Alloc>
+  struct uses_allocator<experimental::function<R(ArgTypes...)>, Alloc>;
+
+} // namespace std
+
+*/
+
+#include <experimental/__config>
+#include <functional>
+#include <algorithm>
+
+#include <__undef_min_max>
+
+#include <__debug>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_LFTS
+
+// default searcher
+template<class _ForwardIterator, class _BinaryPredicate = equal_to<>>
+class default_searcher {
+public:
+    default_searcher(_ForwardIterator __f, _ForwardIterator __l, 
+                       _BinaryPredicate __p = _BinaryPredicate())
+        : __first_(__f), __last_(__l), __pred_(__p) {}
+
+    template <typename _ForwardIterator2>
+    _ForwardIterator2 operator () (_ForwardIterator2 __f, _ForwardIterator2 __l) const {
+        return _VSTD::search(__f, __l, __first_, __last_, __pred_);
+        }
+
+private:
+    _ForwardIterator __first_;
+    _ForwardIterator __last_;
+    _BinaryPredicate __pred_;
+    };
+
+template<class _ForwardIterator, class _BinaryPredicate = equal_to<>>
+default_searcher<_ForwardIterator, _BinaryPredicate>
+make_default_searcher( _ForwardIterator __f, _ForwardIterator __l, _BinaryPredicate __p = _BinaryPredicate ())
+{
+    return default_searcher<_ForwardIterator, _BinaryPredicate>(__f, __l, __p);
+}
+
+
+_LIBCPP_END_NAMESPACE_LFTS
+
+#endif /* _LIBCPP_EXPERIMENTAL_FUNCTIONAL */

diff --git a/libcxx/include/experimental/optional b/libcxx/include/experimental/optional
new file mode 100644
index 0000000..a384882
--- /dev/null
+++ b/libcxx/include/experimental/optional

@@ -0,0 +1,894 @@
+// -*- C++ -*-
+//===-------------------------- optional ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_OPTIONAL
+#define _LIBCPP_OPTIONAL
+
+/*
+    optional synopsis
+
+// C++1y
+
+namespace std { namespace experimental { inline namespace fundamentals_v1 {
+
+    // 5.3, optional for object types
+    template <class T> class optional;
+
+    // 5.4, In-place construction
+    struct in_place_t{};
+    constexpr in_place_t in_place{};
+
+    // 5.5, No-value state indicator
+    struct nullopt_t{see below};
+    constexpr nullopt_t nullopt(unspecified);
+
+    // 5.6, Class bad_optional_access
+    class bad_optional_access;
+
+    // 5.7, Relational operators
+    template <class T>
+      constexpr bool operator==(const optional<T>&, const optional<T>&);
+    template <class T>
+      constexpr bool operator!=(const optional<T>&, const optional<T>&);
+    template <class T>
+      constexpr bool operator<(const optional<T>&, const optional<T>&);
+    template <class T>
+      constexpr bool operator>(const optional<T>&, const optional<T>&);
+    template <class T>
+      constexpr bool operator<=(const optional<T>&, const optional<T>&);
+    template <class T>
+      constexpr bool operator>=(const optional<T>&, const optional<T>&);
+
+    // 5.8, Comparison with nullopt
+    template <class T> constexpr bool operator==(const optional<T>&, nullopt_t) noexcept;
+    template <class T> constexpr bool operator==(nullopt_t, const optional<T>&) noexcept;
+    template <class T> constexpr bool operator!=(const optional<T>&, nullopt_t) noexcept;
+    template <class T> constexpr bool operator!=(nullopt_t, const optional<T>&) noexcept;
+    template <class T> constexpr bool operator<(const optional<T>&, nullopt_t) noexcept;
+    template <class T> constexpr bool operator<(nullopt_t, const optional<T>&) noexcept;
+    template <class T> constexpr bool operator<=(const optional<T>&, nullopt_t) noexcept;
+    template <class T> constexpr bool operator<=(nullopt_t, const optional<T>&) noexcept;
+    template <class T> constexpr bool operator>(const optional<T>&, nullopt_t) noexcept;
+    template <class T> constexpr bool operator>(nullopt_t, const optional<T>&) noexcept;
+    template <class T> constexpr bool operator>=(const optional<T>&, nullopt_t) noexcept;
+    template <class T> constexpr bool operator>=(nullopt_t, const optional<T>&) noexcept;
+
+    // 5.9, Comparison with T
+    template <class T> constexpr bool operator==(const optional<T>&, const T&);
+    template <class T> constexpr bool operator==(const T&, const optional<T>&);
+    template <class T> constexpr bool operator!=(const optional<T>&, const T&);
+    template <class T> constexpr bool operator!=(const T&, const optional<T>&);
+    template <class T> constexpr bool operator<(const optional<T>&, const T&);
+    template <class T> constexpr bool operator<(const T&, const optional<T>&);
+    template <class T> constexpr bool operator<=(const optional<T>&, const T&);
+    template <class T> constexpr bool operator<=(const T&, const optional<T>&);
+    template <class T> constexpr bool operator>(const optional<T>&, const T&);
+    template <class T> constexpr bool operator>(const T&, const optional<T>&);
+    template <class T> constexpr bool operator>=(const optional<T>&, const T&);
+    template <class T> constexpr bool operator>=(const T&, const optional<T>&);
+
+    // 5.10, Specialized algorithms
+    template <class T> void swap(optional<T>&, optional<T>&) noexcept(see below);
+    template <class T> constexpr optional<see below> make_optional(T&&);
+
+	template <class T>
+	class optional
+	{
+	public:
+	  typedef T value_type;
+
+	  // 5.3.1, Constructors
+	  constexpr optional() noexcept;
+	  constexpr optional(nullopt_t) noexcept;
+	  optional(const optional&);
+	  optional(optional&&) noexcept(see below);
+	  constexpr optional(const T&);
+	  constexpr optional(T&&);
+	  template <class... Args> constexpr explicit optional(in_place_t, Args&&...);
+	  template <class U, class... Args>
+		constexpr explicit optional(in_place_t, initializer_list<U>, Args&&...);
+
+	  // 5.3.2, Destructor
+	  ~optional();
+
+	  // 5.3.3, Assignment
+	  optional& operator=(nullopt_t) noexcept;
+	  optional& operator=(const optional&);
+	  optional& operator=(optional&&) noexcept(see below);
+	  template <class U> optional& operator=(U&&);
+	  template <class... Args> void emplace(Args&&...);
+	  template <class U, class... Args>
+		void emplace(initializer_list<U>, Args&&...);
+
+	  // 5.3.4, Swap
+	  void swap(optional&) noexcept(see below);
+
+	  // 5.3.5, Observers
+	  constexpr T const* operator ->() const;
+	  constexpr T* operator ->();
+	  constexpr T const& operator *() const &;
+	  constexpr T& operator *() &;
+	  constexpr T&& operator *() &&;
+	  constexpr const T&& operator *() const &&;
+	  constexpr explicit operator bool() const noexcept;
+	  constexpr T const& value() const &;
+	  constexpr T& value() &;
+	  constexpr T&& value() &&;
+	  constexpr const T&& value() const &&;
+	  template <class U> constexpr T value_or(U&&) const &;
+	  template <class U> constexpr T value_or(U&&) &&;
+
+	private:
+	  T*   val;  // exposition only
+	};
+
+  } // namespace fundamentals_v1
+  } // namespace experimental
+
+  // 5.11, Hash support
+  template <class T> struct hash;
+  template <class T> struct hash<experimental::optional<T>>;
+
+} // namespace std
+
+*/
+
+#include <experimental/__config>
+#include <functional>
+#include <stdexcept>
+
+_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL
+class _LIBCPP_EXCEPTION_ABI bad_optional_access
+    : public std::logic_error
+{
+public:
+	bad_optional_access() : std::logic_error("Bad optional Access") {}
+
+//	Get the key function ~bad_optional_access() into the dylib
+    virtual ~bad_optional_access() _NOEXCEPT;
+};
+
+_LIBCPP_END_NAMESPACE_EXPERIMENTAL
+
+
+#if _LIBCPP_STD_VER > 11
+
+#include <initializer_list>
+#include <type_traits>
+#include <new>
+#include <__functional_base>
+#include <__undef_min_max>
+#include <__debug>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_LFTS
+
+struct in_place_t {};
+constexpr in_place_t in_place{};
+
+struct nullopt_t
+{
+    explicit constexpr nullopt_t(int) noexcept {}
+};
+
+constexpr nullopt_t nullopt{0};
+
+template <class _Tp, bool = is_trivially_destructible<_Tp>::value>
+class __optional_storage
+{
+protected:
+    typedef _Tp value_type;
+    union
+    {
+        char __null_state_;
+        value_type __val_;
+    };
+    bool __engaged_ = false;
+
+    _LIBCPP_INLINE_VISIBILITY
+    ~__optional_storage()
+    {
+        if (__engaged_)
+            __val_.~value_type();
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr __optional_storage() noexcept
+        :  __null_state_('\0') {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __optional_storage(const __optional_storage& __x)
+        :  __engaged_(__x.__engaged_)
+        {
+            if (__engaged_)
+                ::new(_VSTD::addressof(__val_)) value_type(__x.__val_);
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __optional_storage(__optional_storage&& __x)
+                      noexcept(is_nothrow_move_constructible<value_type>::value)
+        :  __engaged_(__x.__engaged_)
+        {
+            if (__engaged_)
+                ::new(_VSTD::addressof(__val_)) value_type(_VSTD::move(__x.__val_));
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr __optional_storage(const value_type& __v)
+        :  __val_(__v),
+           __engaged_(true) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr __optional_storage(value_type&& __v)
+        :  __val_(_VSTD::move(__v)),
+           __engaged_(true) {}
+
+    template <class... _Args>
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr
+    explicit __optional_storage(in_place_t, _Args&&... __args)
+       :  __val_(_VSTD::forward<_Args>(__args)...),
+           __engaged_(true) {}
+};
+
+template <class _Tp>
+class __optional_storage<_Tp, true>
+{
+protected:
+    typedef _Tp value_type;
+    union
+    {
+        char __null_state_;
+        value_type __val_;
+    };
+    bool __engaged_ = false;
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr __optional_storage() noexcept
+        :  __null_state_('\0') {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __optional_storage(const __optional_storage& __x)
+        :  __engaged_(__x.__engaged_)
+        {
+            if (__engaged_)
+                ::new(_VSTD::addressof(__val_)) value_type(__x.__val_);
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __optional_storage(__optional_storage&& __x)
+                      noexcept(is_nothrow_move_constructible<value_type>::value)
+        :  __engaged_(__x.__engaged_)
+        {
+            if (__engaged_)
+                ::new(_VSTD::addressof(__val_)) value_type(_VSTD::move(__x.__val_));
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr __optional_storage(const value_type& __v)
+        :  __val_(__v),
+           __engaged_(true) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr __optional_storage(value_type&& __v)
+        :  __val_(_VSTD::move(__v)),
+           __engaged_(true) {}
+
+    template <class... _Args>
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr
+    explicit __optional_storage(in_place_t, _Args&&... __args)
+       :  __val_(_VSTD::forward<_Args>(__args)...),
+           __engaged_(true) {}
+};
+
+template <class _Tp>
+class optional
+    : private __optional_storage<_Tp>
+{
+    typedef __optional_storage<_Tp> __base;
+public:
+    typedef _Tp value_type;
+
+    static_assert(!is_reference<value_type>::value,
+              "Instantiation of optional with a reference type is ill-formed.");
+    static_assert(!is_same<typename remove_cv<value_type>::type, in_place_t>::value,
+              "Instantiation of optional with a in_place_t type is ill-formed.");
+    static_assert(!is_same<typename remove_cv<value_type>::type, nullopt_t>::value,
+              "Instantiation of optional with a nullopt_t type is ill-formed.");
+    static_assert(is_object<value_type>::value,
+        "Instantiation of optional with a non-object type is undefined behavior.");
+    static_assert(is_nothrow_destructible<value_type>::value,
+        "Instantiation of optional with an object type that is not noexcept destructible is undefined behavior.");
+
+    _LIBCPP_INLINE_VISIBILITY constexpr optional() noexcept {}
+    _LIBCPP_INLINE_VISIBILITY optional(const optional&) = default;
+    _LIBCPP_INLINE_VISIBILITY optional(optional&&) = default;
+    _LIBCPP_INLINE_VISIBILITY ~optional() = default;
+    _LIBCPP_INLINE_VISIBILITY constexpr optional(nullopt_t) noexcept {}
+    _LIBCPP_INLINE_VISIBILITY constexpr optional(const value_type& __v)
+        : __base(__v) {}
+    _LIBCPP_INLINE_VISIBILITY constexpr optional(value_type&& __v)
+        : __base(_VSTD::move(__v)) {}
+
+    template <class... _Args,
+              class = typename enable_if
+                      <
+                           is_constructible<value_type, _Args...>::value
+                      >::type
+             >
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr
+    explicit optional(in_place_t, _Args&&... __args)
+        : __base(in_place, _VSTD::forward<_Args>(__args)...) {}
+
+    template <class _Up, class... _Args,
+              class = typename enable_if
+                      <
+                           is_constructible<value_type, initializer_list<_Up>&, _Args...>::value
+                      >::type
+             >
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr
+    explicit optional(in_place_t, initializer_list<_Up> __il, _Args&&... __args)
+        : __base(in_place, __il, _VSTD::forward<_Args>(__args)...) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    optional& operator=(nullopt_t) noexcept
+    {
+        if (this->__engaged_)
+        {
+            this->__val_.~value_type();
+            this->__engaged_ = false;
+        }
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    optional&
+    operator=(const optional& __opt)
+    {
+        if (this->__engaged_ == __opt.__engaged_)
+        {
+            if (this->__engaged_)
+                this->__val_ = __opt.__val_;
+        }
+        else
+        {
+            if (this->__engaged_)
+                this->__val_.~value_type();
+            else
+                ::new(_VSTD::addressof(this->__val_)) value_type(__opt.__val_);
+            this->__engaged_ = __opt.__engaged_;
+        }
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    optional&
+    operator=(optional&& __opt)
+        noexcept(is_nothrow_move_assignable<value_type>::value &&
+                 is_nothrow_move_constructible<value_type>::value)
+    {
+        if (this->__engaged_ == __opt.__engaged_)
+        {
+            if (this->__engaged_)
+                this->__val_ = _VSTD::move(__opt.__val_);
+        }
+        else
+        {
+            if (this->__engaged_)
+                this->__val_.~value_type();
+            else
+                ::new(_VSTD::addressof(this->__val_)) value_type(_VSTD::move(__opt.__val_));
+            this->__engaged_ = __opt.__engaged_;
+        }
+        return *this;
+    }
+
+    template <class _Up,
+              class = typename enable_if
+                      <
+                          is_same<typename remove_reference<_Up>::type, value_type>::value &&
+                          is_constructible<value_type, _Up>::value &&
+                          is_assignable<value_type&, _Up>::value
+                      >::type
+             >
+    _LIBCPP_INLINE_VISIBILITY
+    optional&
+    operator=(_Up&& __v)
+    {
+        if (this->__engaged_)
+            this->__val_ = _VSTD::forward<_Up>(__v);
+        else
+        {
+            ::new(_VSTD::addressof(this->__val_)) value_type(_VSTD::forward<_Up>(__v));
+            this->__engaged_ = true;
+        }
+        return *this;
+    }
+
+    template <class... _Args,
+              class = typename enable_if
+                      <
+                          is_constructible<value_type, _Args...>::value
+                      >::type
+             >
+    _LIBCPP_INLINE_VISIBILITY
+    void
+    emplace(_Args&&... __args)
+    {
+        *this = nullopt;
+        ::new(_VSTD::addressof(this->__val_)) value_type(_VSTD::forward<_Args>(__args)...);
+        this->__engaged_ = true;
+    }
+
+    template <class _Up, class... _Args,
+              class = typename enable_if
+                      <
+                          is_constructible<value_type, initializer_list<_Up>&, _Args...>::value
+                      >::type
+             >
+    _LIBCPP_INLINE_VISIBILITY
+    void
+    emplace(initializer_list<_Up> __il, _Args&&... __args)
+    {
+        *this = nullopt;
+        ::new(_VSTD::addressof(this->__val_)) value_type(__il, _VSTD::forward<_Args>(__args)...);
+        this->__engaged_ = true;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    void
+    swap(optional& __opt)
+        noexcept(is_nothrow_move_constructible<value_type>::value &&
+                 __is_nothrow_swappable<value_type>::value)
+    {
+        using _VSTD::swap;
+        if (this->__engaged_ == __opt.__engaged_)
+        {
+            if (this->__engaged_)
+                swap(this->__val_, __opt.__val_);
+        }
+        else
+        {
+            if (this->__engaged_)
+            {
+                ::new(_VSTD::addressof(__opt.__val_)) value_type(_VSTD::move(this->__val_));
+                this->__val_.~value_type();
+            }
+            else
+            {
+                ::new(_VSTD::addressof(this->__val_)) value_type(_VSTD::move(__opt.__val_));
+                __opt.__val_.~value_type();
+            }
+            swap(this->__engaged_, __opt.__engaged_);
+        }
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr
+    value_type const*
+    operator->() const
+    {
+        _LIBCPP_ASSERT(this->__engaged_, "optional operator-> called for disengaged value");
+        return __operator_arrow(__has_operator_addressof<value_type>{});
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    value_type*
+    operator->()
+    {
+        _LIBCPP_ASSERT(this->__engaged_, "optional operator-> called for disengaged value");
+        return _VSTD::addressof(this->__val_);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr
+    const value_type&
+    operator*() const
+    {
+        _LIBCPP_ASSERT(this->__engaged_, "optional operator* called for disengaged value");
+        return this->__val_;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    value_type&
+    operator*()
+    {
+        _LIBCPP_ASSERT(this->__engaged_, "optional operator* called for disengaged value");
+        return this->__val_;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr explicit operator bool() const noexcept {return this->__engaged_;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr value_type const& value() const
+    {
+        if (!this->__engaged_)
+            throw bad_optional_access();
+        return this->__val_;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    value_type& value()
+    {
+        if (!this->__engaged_)
+            throw bad_optional_access();
+        return this->__val_;
+    }
+
+    template <class _Up>
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr value_type value_or(_Up&& __v) const&
+    {
+        static_assert(is_copy_constructible<value_type>::value,
+                      "optional<T>::value_or: T must be copy constructible");
+        static_assert(is_convertible<_Up, value_type>::value,
+                      "optional<T>::value_or: U must be convertible to T");
+        return this->__engaged_ ? this->__val_ :
+                                  static_cast<value_type>(_VSTD::forward<_Up>(__v));
+    }
+
+    template <class _Up>
+    _LIBCPP_INLINE_VISIBILITY
+    value_type value_or(_Up&& __v) &&
+    {
+        static_assert(is_move_constructible<value_type>::value,
+                      "optional<T>::value_or: T must be move constructible");
+        static_assert(is_convertible<_Up, value_type>::value,
+                      "optional<T>::value_or: U must be convertible to T");
+        return this->__engaged_ ? _VSTD::move(this->__val_) :
+                                  static_cast<value_type>(_VSTD::forward<_Up>(__v));
+    }
+
+private:
+    _LIBCPP_INLINE_VISIBILITY
+    value_type const*
+    __operator_arrow(true_type) const
+    {
+        return _VSTD::addressof(this->__val_);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr
+    value_type const*
+    __operator_arrow(false_type) const
+    {
+        return &this->__val_;
+    }
+};
+
+// Comparisons between optionals
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator==(const optional<_Tp>& __x, const optional<_Tp>& __y)
+{
+    if (static_cast<bool>(__x) != static_cast<bool>(__y))
+        return false;
+    if (!static_cast<bool>(__x))
+        return true;
+    return *__x == *__y;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator!=(const optional<_Tp>& __x, const optional<_Tp>& __y)
+{
+    return !(__x == __y);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator<(const optional<_Tp>& __x, const optional<_Tp>& __y)
+{
+    if (!static_cast<bool>(__y))
+        return false;
+    if (!static_cast<bool>(__x))
+        return true;
+    return *__x < *__y;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator>(const optional<_Tp>& __x, const optional<_Tp>& __y)
+{
+    return __y < __x;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator<=(const optional<_Tp>& __x, const optional<_Tp>& __y)
+{
+    return !(__y < __x);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator>=(const optional<_Tp>& __x, const optional<_Tp>& __y)
+{
+    return !(__x < __y);
+}
+
+
+// Comparisons with nullopt
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator==(const optional<_Tp>& __x, nullopt_t) noexcept
+{
+    return !static_cast<bool>(__x);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator==(nullopt_t, const optional<_Tp>& __x) noexcept
+{
+    return !static_cast<bool>(__x);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator!=(const optional<_Tp>& __x, nullopt_t) noexcept
+{
+    return static_cast<bool>(__x);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator!=(nullopt_t, const optional<_Tp>& __x) noexcept
+{
+    return static_cast<bool>(__x);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator<(const optional<_Tp>&, nullopt_t) noexcept
+{
+    return false;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator<(nullopt_t, const optional<_Tp>& __x) noexcept
+{
+    return static_cast<bool>(__x);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator<=(const optional<_Tp>& __x, nullopt_t) noexcept
+{
+    return !static_cast<bool>(__x);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator<=(nullopt_t, const optional<_Tp>& __x) noexcept
+{
+    return true;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator>(const optional<_Tp>& __x, nullopt_t) noexcept
+{
+    return static_cast<bool>(__x);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator>(nullopt_t, const optional<_Tp>& __x) noexcept
+{
+    return false;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator>=(const optional<_Tp>&, nullopt_t) noexcept
+{
+    return true;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator>=(nullopt_t, const optional<_Tp>& __x) noexcept
+{
+    return !static_cast<bool>(__x);
+}
+
+// Comparisons with T
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator==(const optional<_Tp>& __x, const _Tp& __v)
+{
+    return static_cast<bool>(__x) ? *__x == __v : false;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator==(const _Tp& __v, const optional<_Tp>& __x)
+{
+    return static_cast<bool>(__x) ? *__x == __v : false;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator!=(const optional<_Tp>& __x, const _Tp& __v)
+{
+    return static_cast<bool>(__x) ? !(*__x == __v) : true;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator!=(const _Tp& __v, const optional<_Tp>& __x)
+{
+    return static_cast<bool>(__x) ? !(*__x == __v) : true;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator<(const optional<_Tp>& __x, const _Tp& __v)
+{
+    return static_cast<bool>(__x) ? less<_Tp>{}(*__x, __v) : true;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator<(const _Tp& __v, const optional<_Tp>& __x)
+{
+    return static_cast<bool>(__x) ? less<_Tp>{}(__v, *__x) : false;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator<=(const optional<_Tp>& __x, const _Tp& __v)
+{
+    return !(__x > __v);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator<=(const _Tp& __v, const optional<_Tp>& __x)
+{
+    return !(__v > __x);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator>(const optional<_Tp>& __x, const _Tp& __v)
+{
+    return static_cast<bool>(__x) ? __v < __x : false;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator>(const _Tp& __v, const optional<_Tp>& __x)
+{
+    return static_cast<bool>(__x) ? __x < __v : true;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator>=(const optional<_Tp>& __x, const _Tp& __v)
+{
+    return !(__x < __v);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+bool
+operator>=(const _Tp& __v, const optional<_Tp>& __x)
+{
+    return !(__v < __x);
+}
+
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(optional<_Tp>& __x, optional<_Tp>& __y) noexcept(noexcept(__x.swap(__y)))
+{
+    __x.swap(__y);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+constexpr
+optional<typename decay<_Tp>::type>
+make_optional(_Tp&& __v)
+{
+    return optional<typename decay<_Tp>::type>(_VSTD::forward<_Tp>(__v));
+}
+
+_LIBCPP_END_NAMESPACE_LFTS
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp>
+struct _LIBCPP_TYPE_VIS_ONLY hash<std::experimental::optional<_Tp> >
+{
+    typedef std::experimental::optional<_Tp> argument_type;
+    typedef size_t        result_type;
+
+    _LIBCPP_INLINE_VISIBILITY
+    result_type operator()(const argument_type& __opt) const _NOEXCEPT
+    {
+        return static_cast<bool>(__opt) ? hash<_Tp>()(*__opt) : 0;
+    }
+};
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_STD_VER > 11
+
+#endif  // _LIBCPP_OPTIONAL

diff --git a/libcxx/include/experimental/ratio b/libcxx/include/experimental/ratio
new file mode 100644
index 0000000..757f24e
--- /dev/null
+++ b/libcxx/include/experimental/ratio

@@ -0,0 +1,77 @@
+// -*- C++ -*-
+//===------------------------------ ratio ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_EXPERIMENTAL_RATIO
+#define _LIBCPP_EXPERIMENTAL_RATIO
+
+/**
+    experimental/ratio synopsis
+    C++1y
+#include <ratio>
+
+namespace std {
+namespace experimental {
+inline namespace fundamentals_v1 {
+
+  // See C++14 20.11.5, ratio comparison
+  template <class R1, class R2> constexpr bool ratio_equal_v
+    = ratio_equal<R1, R2>::value;
+  template <class R1, class R2> constexpr bool ratio_not_equal_v
+    = ratio_not_equal<R1, R2>::value;
+  template <class R1, class R2> constexpr bool ratio_less_v
+    = ratio_less<R1, R2>::value;
+  template <class R1, class R2> constexpr bool ratio_less_equal_v
+    = ratio_less_equal<R1, R2>::value;
+  template <class R1, class R2> constexpr bool ratio_greater_v
+    = ratio_greater<R1, R2>::value;
+  template <class R1, class R2> constexpr bool ratio_greater_equal_v
+    = ratio_greater_equal<R1, R2>::value;
+
+} // namespace fundamentals_v1
+} // namespace experimental
+} // namespace std
+
+*/
+
+#include <experimental/__config>
+
+#if _LIBCPP_STD_VER > 11
+
+#include <ratio>
+
+_LIBCPP_BEGIN_NAMESPACE_LFTS
+
+#ifndef _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
+
+template <class _R1, class _R2> _LIBCPP_CONSTEXPR bool ratio_equal_v
+    = ratio_equal<_R1, _R2>::value;
+
+template <class _R1, class _R2> _LIBCPP_CONSTEXPR bool ratio_not_equal_v
+    = ratio_not_equal<_R1, _R2>::value;
+
+template <class _R1, class _R2> _LIBCPP_CONSTEXPR bool ratio_less_v
+    = ratio_less<_R1, _R2>::value;
+
+template <class _R1, class _R2> _LIBCPP_CONSTEXPR bool ratio_less_equal_v
+    = ratio_less_equal<_R1, _R2>::value;
+
+template <class _R1, class _R2> _LIBCPP_CONSTEXPR bool ratio_greater_v
+    = ratio_greater<_R1, _R2>::value;
+
+template <class _R1, class _R2> _LIBCPP_CONSTEXPR bool ratio_greater_equal_v
+    = ratio_greater_equal<_R1, _R2>::value;
+
+#endif /* _LIBCPP_HAS_NO_VARIABLE_TEMPLATES */
+
+_LIBCPP_END_NAMESPACE_LFTS
+
+#endif /* _LIBCPP_STD_VER > 11 */
+
+#endif // _LIBCPP_EXPERIMENTAL_RATIO

diff --git a/libcxx/include/experimental/string_view b/libcxx/include/experimental/string_view
new file mode 100644
index 0000000..2a20d7c
--- /dev/null
+++ b/libcxx/include/experimental/string_view

@@ -0,0 +1,812 @@
+// -*- C++ -*-
+//===------------------------ string_view ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_LFTS_STRING_VIEW
+#define _LIBCPP_LFTS_STRING_VIEW
+
+/*
+string_view synopsis
+
+namespace std {
+ namespace experimental {
+  inline namespace library_fundamentals_v1 {
+
+    // 7.2, Class template basic_string_view
+    template<class charT, class traits = char_traits<charT>>
+        class basic_string_view;
+
+    // 7.9, basic_string_view non-member comparison functions
+    template<class charT, class traits>
+    constexpr bool operator==(basic_string_view<charT, traits> x,
+                              basic_string_view<charT, traits> y) noexcept;
+    template<class charT, class traits>
+    constexpr bool operator!=(basic_string_view<charT, traits> x,
+                              basic_string_view<charT, traits> y) noexcept;
+    template<class charT, class traits>
+    constexpr bool operator< (basic_string_view<charT, traits> x,
+                                 basic_string_view<charT, traits> y) noexcept;
+    template<class charT, class traits>
+    constexpr bool operator> (basic_string_view<charT, traits> x,
+                              basic_string_view<charT, traits> y) noexcept;
+    template<class charT, class traits>
+    constexpr bool operator<=(basic_string_view<charT, traits> x,
+                                 basic_string_view<charT, traits> y) noexcept;
+    template<class charT, class traits>
+    constexpr bool operator>=(basic_string_view<charT, traits> x,
+                              basic_string_view<charT, traits> y) noexcept;
+    // see below, sufficient additional overloads of comparison functions
+
+    // 7.10, Inserters and extractors
+    template<class charT, class traits>
+      basic_ostream<charT, traits>&
+        operator<<(basic_ostream<charT, traits>& os,
+                   basic_string_view<charT, traits> str);
+
+    // basic_string_view typedef names
+    typedef basic_string_view<char> string_view;
+    typedef basic_string_view<char16_t> u16string_view;
+    typedef basic_string_view<char32_t> u32string_view;
+    typedef basic_string_view<wchar_t> wstring_view;
+
+    template<class charT, class traits = char_traits<charT>>
+    class basic_string_view {
+      public:
+      // types
+      typedef traits traits_type;
+      typedef charT value_type;
+      typedef charT* pointer;
+      typedef const charT* const_pointer;
+      typedef charT& reference;
+      typedef const charT& const_reference;
+      typedef implementation-defined const_iterator;
+      typedef const_iterator iterator;
+      typedef reverse_iterator<const_iterator> const_reverse_iterator;
+      typedef const_reverse_iterator reverse_iterator;
+      typedef size_t size_type;
+      typedef ptrdiff_t difference_type;
+      static constexpr size_type npos = size_type(-1);
+
+      // 7.3, basic_string_view constructors and assignment operators
+      constexpr basic_string_view() noexcept;
+      constexpr basic_string_view(const basic_string_view&) noexcept = default;
+      basic_string_view& operator=(const basic_string_view&) noexcept = default;
+      template<class Allocator>
+      basic_string_view(const basic_string<charT, traits, Allocator>& str) noexcept;
+      constexpr basic_string_view(const charT* str);
+      constexpr basic_string_view(const charT* str, size_type len);
+
+      // 7.4, basic_string_view iterator support
+      constexpr const_iterator begin() const noexcept;
+      constexpr const_iterator end() const noexcept;
+      constexpr const_iterator cbegin() const noexcept;
+      constexpr const_iterator cend() const noexcept;
+      const_reverse_iterator rbegin() const noexcept;
+      const_reverse_iterator rend() const noexcept;
+      const_reverse_iterator crbegin() const noexcept;
+      const_reverse_iterator crend() const noexcept;
+
+      // 7.5, basic_string_view capacity
+      constexpr size_type size() const noexcept;
+      constexpr size_type length() const noexcept;
+      constexpr size_type max_size() const noexcept;
+      constexpr bool empty() const noexcept;
+
+      // 7.6, basic_string_view element access
+      constexpr const_reference operator[](size_type pos) const;
+      constexpr const_reference at(size_type pos) const;
+      constexpr const_reference front() const;
+      constexpr const_reference back() const;
+      constexpr const_pointer data() const noexcept;
+
+      // 7.7, basic_string_view modifiers
+      constexpr void clear() noexcept;
+      constexpr void remove_prefix(size_type n);
+      constexpr void remove_suffix(size_type n);
+      constexpr void swap(basic_string_view& s) noexcept;
+
+      // 7.8, basic_string_view string operations
+      template<class Allocator>
+      explicit operator basic_string<charT, traits, Allocator>() const;
+      template<class Allocator = allocator<charT>>
+      basic_string<charT, traits, Allocator> to_string(
+        const Allocator& a = Allocator()) const;
+
+      size_type copy(charT* s, size_type n, size_type pos = 0) const;
+
+      constexpr basic_string_view substr(size_type pos = 0, size_type n = npos) const;
+      constexpr int compare(basic_string_view s) const noexcept;
+      constexpr int compare(size_type pos1, size_type n1, basic_string_view s) const;
+      constexpr int compare(size_type pos1, size_type n1,
+                            basic_string_view s, size_type pos2, size_type n2) const;
+      constexpr int compare(const charT* s) const;
+      constexpr int compare(size_type pos1, size_type n1, const charT* s) const;
+      constexpr int compare(size_type pos1, size_type n1,
+                            const charT* s, size_type n2) const;
+      constexpr size_type find(basic_string_view s, size_type pos = 0) const noexcept;
+      constexpr size_type find(charT c, size_type pos = 0) const noexcept;
+      constexpr size_type find(const charT* s, size_type pos, size_type n) const;
+      constexpr size_type find(const charT* s, size_type pos = 0) const;
+      constexpr size_type rfind(basic_string_view s, size_type pos = npos) const noexcept;
+      constexpr size_type rfind(charT c, size_type pos = npos) const noexcept;
+      constexpr size_type rfind(const charT* s, size_type pos, size_type n) const;
+      constexpr size_type rfind(const charT* s, size_type pos = npos) const;
+      constexpr size_type find_first_of(basic_string_view s, size_type pos = 0) const noexcept;
+      constexpr size_type find_first_of(charT c, size_type pos = 0) const noexcept;
+      constexpr size_type find_first_of(const charT* s, size_type pos, size_type n) const;
+      constexpr size_type find_first_of(const charT* s, size_type pos = 0) const;
+      constexpr size_type find_last_of(basic_string_view s, size_type pos = npos) const noexcept;
+      constexpr size_type find_last_of(charT c, size_type pos = npos) const noexcept;
+      constexpr size_type find_last_of(const charT* s, size_type pos, size_type n) const;
+      constexpr size_type find_last_of(const charT* s, size_type pos = npos) const;
+      constexpr size_type find_first_not_of(basic_string_view s, size_type pos = 0) const noexcept;
+      constexpr size_type find_first_not_of(charT c, size_type pos = 0) const noexcept;
+      constexpr size_type find_first_not_of(const charT* s, size_type pos, size_type n) const;
+      constexpr size_type find_first_not_of(const charT* s, size_type pos = 0) const;
+      constexpr size_type find_last_not_of(basic_string_view s, size_type pos = npos) const noexcept;
+      constexpr size_type find_last_not_of(charT c, size_type pos = npos) const noexcept;
+      constexpr size_type find_last_not_of(const charT* s, size_type pos, size_type n) const;
+      constexpr size_type find_last_not_of(const charT* s, size_type pos = npos) const;
+
+     private:
+      const_pointer data_;  // exposition only
+      size_type     size_;  // exposition only
+    };
+
+  }  // namespace fundamentals_v1
+ }  // namespace experimental
+
+  // 7.11, Hash support
+  template <class T> struct hash;
+  template <> struct hash<experimental::string_view>;
+  template <> struct hash<experimental::u16string_view>;
+  template <> struct hash<experimental::u32string_view>;
+  template <> struct hash<experimental::wstring_view>;
+
+}  // namespace std
+
+
+*/
+
+#include <experimental/__config>
+
+#include <string>
+#include <algorithm>
+#include <iterator>
+#include <ostream>
+#include <iomanip>
+
+#include <__debug>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_LFTS
+
+    template<class _CharT, class _Traits = _VSTD::char_traits<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY basic_string_view {
+    public:
+        // types
+        typedef _Traits                                    traits_type;
+        typedef _CharT                                     value_type;
+        typedef const _CharT*                              pointer;
+        typedef const _CharT*                              const_pointer;
+        typedef const _CharT&                              reference;
+        typedef const _CharT&                              const_reference;
+        typedef const_pointer                              const_iterator; // See [string.view.iterators]
+        typedef const_iterator                             iterator;
+        typedef _VSTD::reverse_iterator<const_iterator>    const_reverse_iterator;
+        typedef const_reverse_iterator                     reverse_iterator;
+        typedef size_t                                     size_type;
+        typedef ptrdiff_t                                  difference_type;
+        static _LIBCPP_CONSTEXPR const size_type npos = -1; // size_type(-1);
+
+        // [string.view.cons], construct/copy
+        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
+        basic_string_view() _NOEXCEPT : __data (nullptr), __size(0) {}
+
+        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
+        basic_string_view(const basic_string_view&) _NOEXCEPT = default;
+
+        _LIBCPP_INLINE_VISIBILITY
+        basic_string_view& operator=(const basic_string_view&) _NOEXCEPT = default;
+
+        template<class _Allocator>
+        _LIBCPP_INLINE_VISIBILITY
+        basic_string_view(const basic_string<_CharT, _Traits, _Allocator>& __str) _NOEXCEPT
+            : __data (__str.data()), __size(__str.size()) {}
+
+        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
+        basic_string_view(const _CharT* __s, size_type __len)
+            : __data(__s), __size(__len)
+        {
+//             _LIBCPP_ASSERT(__len == 0 || __s != nullptr, "string_view::string_view(_CharT *, size_t): recieved nullptr");
+        }
+
+        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
+        basic_string_view(const _CharT* __s)
+            : __data(__s), __size(_Traits::length(__s)) {}
+
+        // [string.view.iterators], iterators
+        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
+        const_iterator begin()  const _NOEXCEPT { return cbegin(); }
+
+        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
+        const_iterator end()    const _NOEXCEPT { return cend(); }
+
+        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
+        const_iterator cbegin() const _NOEXCEPT { return __data; }
+
+        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
+        const_iterator cend()   const _NOEXCEPT { return __data + __size; }
+
+        _LIBCPP_INLINE_VISIBILITY
+        const_reverse_iterator rbegin()   const _NOEXCEPT { return const_reverse_iterator(cend()); }
+
+        _LIBCPP_INLINE_VISIBILITY
+        const_reverse_iterator rend()     const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
+
+        _LIBCPP_INLINE_VISIBILITY
+        const_reverse_iterator crbegin()  const _NOEXCEPT { return const_reverse_iterator(cend()); }
+
+        _LIBCPP_INLINE_VISIBILITY
+        const_reverse_iterator crend()    const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
+
+        // [string.view.capacity], capacity
+        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
+        size_type size()     const _NOEXCEPT { return __size; }
+
+        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
+        size_type length()   const _NOEXCEPT { return __size; }
+
+        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
+        size_type max_size() const _NOEXCEPT { return _VSTD::numeric_limits<size_type>::max(); }
+
+        _LIBCPP_CONSTEXPR bool _LIBCPP_INLINE_VISIBILITY
+        empty()         const _NOEXCEPT { return __size == 0; }
+
+        // [string.view.access], element access
+        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
+        const_reference operator[](size_type __pos) const { return __data[__pos]; }
+
+        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
+        const_reference at(size_type __pos) const
+        {
+            return __pos >= size()
+                ? (throw out_of_range("string_view::at"), __data[0])
+                : __data[__pos];
+        }
+
+        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
+        const_reference front() const
+        {
+            return _LIBCPP_ASSERT(!empty(), "string_view::front(): string is empty"), __data[0];
+        }
+
+        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
+        const_reference back() const
+        {
+            return _LIBCPP_ASSERT(!empty(), "string_view::back(): string is empty"), __data[__size-1];
+        }
+
+        _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
+        const_pointer data() const _NOEXCEPT { return __data; }
+
+        // [string.view.modifiers], modifiers:
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        void clear() _NOEXCEPT
+        {
+            __data = nullptr;
+            __size = 0;
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        void remove_prefix(size_type __n) _NOEXCEPT
+        {
+            _LIBCPP_ASSERT(__n <= size(), "remove_prefix() can't remove more than size()");
+            __data += __n;
+            __size -= __n;
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        void remove_suffix(size_type __n) _NOEXCEPT
+        {
+            _LIBCPP_ASSERT(__n <= size(), "remove_suffix() can't remove more than size()");
+            __size -= __n;
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        void swap(basic_string_view& __other) _NOEXCEPT
+        {
+            const value_type *__p = __data;
+            __data = __other.__data;
+            __other.__data = __p;
+
+            size_type __sz = __size;
+            __size = __other.__size;
+            __other.__size = __sz;
+//             _VSTD::swap( __data, __other.__data );
+//             _VSTD::swap( __size, __other.__size );
+        }
+
+        // [string.view.ops], string operations:
+        template<class _Allocator>
+        _LIBCPP_INLINE_VISIBILITY
+        _LIBCPP_EXPLICIT operator basic_string<_CharT, _Traits, _Allocator>() const
+        { return basic_string<_CharT, _Traits, _Allocator>( begin(), end()); }
+
+        template<class _Allocator = allocator<_CharT> >
+        _LIBCPP_INLINE_VISIBILITY
+        basic_string<_CharT, _Traits, _Allocator>
+        to_string( const _Allocator& __a = _Allocator()) const
+        { return basic_string<_CharT, _Traits, _Allocator> ( begin(), end(), __a ); }
+
+        size_type copy(_CharT* __s, size_type __n, size_type __pos = 0) const
+        {
+            if ( __pos > size())
+                throw out_of_range("string_view::copy");
+            size_type __rlen = _VSTD::min( __n, size() - __pos );
+            _VSTD::copy_n(begin() + __pos, __rlen, __s );
+            return __rlen;
+        }
+
+        _LIBCPP_CONSTEXPR
+        basic_string_view substr(size_type __pos = 0, size_type __n = npos) const
+        {
+//             if (__pos > size())
+//                 throw out_of_range("string_view::substr");
+//             size_type __rlen = _VSTD::min( __n, size() - __pos );
+//             return basic_string_view(data() + __pos, __rlen);
+            return __pos > size()
+                ? throw out_of_range("string_view::substr")
+                : basic_string_view(data() + __pos, _VSTD::min(__n, size() - __pos));
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 int compare(basic_string_view __sv) const _NOEXCEPT
+        {
+            size_type __rlen = _VSTD::min( size(), __sv.size());
+            int __retval = _Traits::compare(data(), __sv.data(), __rlen);
+            if ( __retval == 0 ) // first __rlen chars matched
+                __retval = size() == __sv.size() ? 0 : ( size() < __sv.size() ? -1 : 1 );
+            return __retval;
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        int compare(size_type __pos1, size_type __n1, basic_string_view __sv) const
+        {
+            return substr(__pos1, __n1).compare(__sv);
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        int compare(                       size_type __pos1, size_type __n1, 
+                    basic_string_view _sv, size_type __pos2, size_type __n2) const
+        {
+            return substr(__pos1, __n1).compare(_sv.substr(__pos2, __n2));
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        int compare(const _CharT* __s) const
+        {
+            return compare(basic_string_view(__s));
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        int compare(size_type __pos1, size_type __n1, const _CharT* __s) const
+        {
+            return substr(__pos1, __n1).compare(basic_string_view(__s));
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        int compare(size_type __pos1, size_type __n1, const _CharT* __s, size_type __n2) const
+        {
+            return substr(__pos1, __n1).compare(basic_string_view(__s, __n2));
+        }
+
+        // find
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
+        {
+            _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): recieved nullptr");
+            return _VSTD::__str_find<value_type, size_type, traits_type, npos>
+                (data(), size(), __s.data(), __pos, __s.size());
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find(_CharT __c, size_type __pos = 0) const _NOEXCEPT
+        {
+            return _VSTD::__str_find<value_type, size_type, traits_type, npos>
+                (data(), size(), __c, __pos);
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find(const _CharT* __s, size_type __pos, size_type __n) const
+        {
+            _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find(): recieved nullptr");
+            return _VSTD::__str_find<value_type, size_type, traits_type, npos>
+                (data(), size(), __s, __pos, __n);
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find(const _CharT* __s, size_type __pos = 0) const
+        {
+            _LIBCPP_ASSERT(__s != nullptr, "string_view::find(): recieved nullptr");
+            return _VSTD::__str_find<value_type, size_type, traits_type, npos>
+                (data(), size(), __s, __pos, traits_type::length(__s));
+        }
+
+        // rfind
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type rfind(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT
+        {
+            _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): recieved nullptr");
+            return _VSTD::__str_rfind<value_type, size_type, traits_type, npos>
+                (data(), size(), __s.data(), __pos, __s.size());
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type rfind(_CharT __c, size_type __pos = npos) const _NOEXCEPT
+        {
+            return _VSTD::__str_rfind<value_type, size_type, traits_type, npos>
+                (data(), size(), __c, __pos);
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type rfind(const _CharT* __s, size_type __pos, size_type __n) const
+        {
+            _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::rfind(): recieved nullptr");
+            return _VSTD::__str_rfind<value_type, size_type, traits_type, npos>
+                (data(), size(), __s, __pos, __n);
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type rfind(const _CharT* __s, size_type __pos=npos) const
+        {
+            _LIBCPP_ASSERT(__s != nullptr, "string_view::rfind(): recieved nullptr");
+            return _VSTD::__str_rfind<value_type, size_type, traits_type, npos>
+                (data(), size(), __s, __pos, traits_type::length(__s));
+        }
+
+        // find_first_of
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find_first_of(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
+        {
+            _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_of(): recieved nullptr");
+            return _VSTD::__str_find_first_of<value_type, size_type, traits_type, npos>
+                (data(), size(), __s.data(), __pos, __s.size());
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find_first_of(_CharT __c, size_type __pos = 0) const _NOEXCEPT
+        { return find(__c, __pos); }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
+        {
+            _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_of(): recieved nullptr");
+            return _VSTD::__str_find_first_of<value_type, size_type, traits_type, npos>
+                (data(), size(), __s, __pos, __n);
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find_first_of(const _CharT* __s, size_type __pos=0) const
+        {
+            _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_of(): recieved nullptr");
+            return _VSTD::__str_find_first_of<value_type, size_type, traits_type, npos>
+                (data(), size(), __s, __pos, traits_type::length(__s));
+        }
+
+        // find_last_of
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find_last_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
+        {
+            _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_of(): recieved nullptr");
+            return _VSTD::__str_find_last_of<value_type, size_type, traits_type, npos>
+                (data(), size(), __s.data(), __pos, __s.size());
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find_last_of(_CharT __c, size_type __pos = npos) const _NOEXCEPT
+        { return rfind(__c, __pos); }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
+        {
+            _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_of(): recieved nullptr");
+            return _VSTD::__str_find_last_of<value_type, size_type, traits_type, npos>
+                (data(), size(), __s, __pos, __n);
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find_last_of(const _CharT* __s, size_type __pos=npos) const
+        {
+            _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_of(): recieved nullptr");
+            return _VSTD::__str_find_last_of<value_type, size_type, traits_type, npos>
+                (data(), size(), __s, __pos, traits_type::length(__s));
+        }
+
+        // find_first_not_of
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find_first_not_of(basic_string_view __s, size_type __pos=0) const _NOEXCEPT
+        {
+            _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_not_of(): recieved nullptr");
+            return _VSTD::__str_find_first_not_of<value_type, size_type, traits_type, npos>
+                (data(), size(), __s.data(), __pos, __s.size());
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find_first_not_of(_CharT __c, size_type __pos=0) const _NOEXCEPT
+        {
+            return _VSTD::__str_find_first_not_of<value_type, size_type, traits_type, npos>
+                (data(), size(), __c, __pos);
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const
+        {
+            _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_not_of(): recieved nullptr");
+            return _VSTD::__str_find_first_not_of<value_type, size_type, traits_type, npos>
+                (data(), size(), __s, __pos, __n);
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find_first_not_of(const _CharT* __s, size_type __pos=0) const
+        {
+            _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_not_of(): recieved nullptr");
+            return _VSTD::__str_find_first_not_of<value_type, size_type, traits_type, npos>
+                (data(), size(), __s, __pos, traits_type::length(__s));
+        }
+
+        // find_last_not_of
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find_last_not_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
+        {
+            _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_not_of(): recieved nullptr");
+            return _VSTD::__str_find_last_not_of<value_type, size_type, traits_type, npos>
+                (data(), size(), __s.data(), __pos, __s.size());
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find_last_not_of(_CharT __c, size_type __pos=npos) const _NOEXCEPT
+        {
+            return _VSTD::__str_find_last_not_of<value_type, size_type, traits_type, npos>
+                (data(), size(), __c, __pos);
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const
+        {
+            _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_not_of(): recieved nullptr");
+            return _VSTD::__str_find_last_not_of<value_type, size_type, traits_type, npos>
+                (data(), size(), __s, __pos, __n);
+        }
+
+        _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+        size_type find_last_not_of(const _CharT* __s, size_type __pos=npos) const
+        {
+            _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_not_of(): recieved nullptr");
+            return _VSTD::__str_find_last_not_of<value_type, size_type, traits_type, npos>
+                (data(), size(), __s, __pos, traits_type::length(__s));
+        }
+
+    private:
+        const   value_type* __data;
+        size_type           __size;
+    };
+
+
+    // [string.view.comparison]
+    // operator ==
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator==(basic_string_view<_CharT, _Traits> __lhs,
+                    basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
+    {
+        if ( __lhs.size() != __rhs.size()) return false;
+        return __lhs.compare(__rhs) == 0;
+    }
+
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator==(basic_string_view<_CharT, _Traits> __lhs,
+                    typename _VSTD::common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
+    {
+        if ( __lhs.size() != __rhs.size()) return false;
+        return __lhs.compare(__rhs) == 0;
+    }
+
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator==(typename _VSTD::common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
+                    basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
+    {
+        if ( __lhs.size() != __rhs.size()) return false;
+        return __lhs.compare(__rhs) == 0;
+    }
+
+
+    // operator !=
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
+    {
+        if ( __lhs.size() != __rhs.size())
+            return true;
+        return __lhs.compare(__rhs) != 0;
+    }
+
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(basic_string_view<_CharT, _Traits> __lhs,
+                    typename _VSTD::common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
+    {
+        if ( __lhs.size() != __rhs.size())
+            return true;
+        return __lhs.compare(__rhs) != 0;
+    }
+
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(typename _VSTD::common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
+                    basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
+    {
+        if ( __lhs.size() != __rhs.size())
+            return true;
+        return __lhs.compare(__rhs) != 0;
+    }
+
+
+    // operator <
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator<(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
+    {
+        return __lhs.compare(__rhs) < 0;
+    }
+
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator<(basic_string_view<_CharT, _Traits> __lhs,
+                    typename _VSTD::common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
+    {
+        return __lhs.compare(__rhs) < 0;
+    }
+
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator<(typename _VSTD::common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
+                    basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
+    {
+        return __lhs.compare(__rhs) < 0;
+    }
+
+
+    // operator >
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator> (basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
+    {
+        return __lhs.compare(__rhs) > 0;
+    }
+
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator>(basic_string_view<_CharT, _Traits> __lhs,
+                    typename _VSTD::common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
+    {
+        return __lhs.compare(__rhs) > 0;
+    }
+
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator>(typename _VSTD::common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
+                    basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
+    {
+        return __lhs.compare(__rhs) > 0;
+    }
+
+
+    // operator <=
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator<=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
+    {
+        return __lhs.compare(__rhs) <= 0;
+    }
+
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator<=(basic_string_view<_CharT, _Traits> __lhs,
+                    typename _VSTD::common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
+    {
+        return __lhs.compare(__rhs) <= 0;
+    }
+
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator<=(typename _VSTD::common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
+                    basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
+    {
+        return __lhs.compare(__rhs) <= 0;
+    }
+
+
+    // operator >=
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator>=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
+    {
+        return __lhs.compare(__rhs) >= 0;
+    }
+
+
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator>=(basic_string_view<_CharT, _Traits> __lhs,
+                    typename _VSTD::common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
+    {
+        return __lhs.compare(__rhs) >= 0;
+    }
+
+    template<class _CharT, class _Traits>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator>=(typename _VSTD::common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
+                    basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
+    {
+        return __lhs.compare(__rhs) >= 0;
+    }
+
+
+    // [string.view.io]
+    template<class _CharT, class _Traits>
+    basic_ostream<_CharT, _Traits>&
+    operator<<(basic_ostream<_CharT, _Traits>& __os, basic_string_view<_CharT, _Traits> __sv)
+    {
+        return _VSTD::__put_character_sequence(__os, __sv.data(), __sv.size());
+    }
+
+  typedef basic_string_view<char>     string_view;
+  typedef basic_string_view<char16_t> u16string_view;
+  typedef basic_string_view<char32_t> u32string_view;
+  typedef basic_string_view<wchar_t>  wstring_view;
+
+_LIBCPP_END_NAMESPACE_LFTS
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+// [string.view.hash]
+// Shamelessly stolen from <string>
+template<class _CharT, class _Traits>
+struct _LIBCPP_TYPE_VIS_ONLY hash<std::experimental::basic_string_view<_CharT, _Traits> >
+    : public unary_function<std::experimental::basic_string_view<_CharT, _Traits>, size_t>
+{
+    size_t operator()(const std::experimental::basic_string_view<_CharT, _Traits>& __val) const _NOEXCEPT;
+};
+
+template<class _CharT, class _Traits>
+size_t
+hash<std::experimental::basic_string_view<_CharT, _Traits> >::operator()(
+        const std::experimental::basic_string_view<_CharT, _Traits>& __val) const _NOEXCEPT
+{
+    return __do_string_hash(__val.data(), __val.data() + __val.size());
+}
+
+#if _LIBCPP_STD_VER > 11
+template <class _CharT, class _Traits>
+__quoted_output_proxy<_CharT, const _CharT *, _Traits>
+quoted ( std::experimental::basic_string_view <_CharT, _Traits> __sv,
+             _CharT __delim = _CharT('"'), _CharT __escape=_CharT('\\'))
+{
+    return __quoted_output_proxy<_CharT, const _CharT *, _Traits> 
+         ( __sv.data(), __sv.data() + __sv.size(), __delim, __escape );
+}
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_LFTS_STRING_VIEW

diff --git a/libcxx/include/experimental/system_error b/libcxx/include/experimental/system_error
new file mode 100644
index 0000000..2ec2385
--- /dev/null
+++ b/libcxx/include/experimental/system_error

@@ -0,0 +1,63 @@
+// -*- C++ -*-
+//===-------------------------- system_error ------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_EXPERIMENTAL_SYSTEM_ERROR
+#define _LIBCPP_EXPERIMENTAL_SYSTEM_ERROR
+
+/**
+    experimental/system_error synopsis
+
+// C++1y
+
+#include <system_error>
+
+namespace std {
+namespace experimental {
+inline namespace fundamentals_v1 {
+
+  // See C++14 19.5, System error support
+  template <class T> constexpr bool is_error_code_enum_v
+    = is_error_code_enum<T>::value;
+  template <class T> constexpr bool is_error_condition_enum_v
+    = is_error_condition_enum<T>::value;
+
+} // namespace fundamentals_v1
+} // namespace experimental
+} // namespace std
+
+*/
+
+#include <experimental/__config>
+
+#if _LIBCPP_STD_VER > 11
+
+#include <system_error>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_LFTS
+
+#ifndef _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_error_code_enum_v
+    = is_error_code_enum<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_error_condition_enum_v
+    = is_error_condition_enum<_Tp>::value;
+
+#endif /* _LIBCPP_HAS_NO_VARIABLE_TEMPLATES */
+
+_LIBCPP_END_NAMESPACE_LFTS
+
+#endif /* _LIBCPP_STD_VER > 11 */
+
+#endif /* _LIBCPP_EXPERIMENTAL_SYSTEM_ERROR */

diff --git a/libcxx/include/experimental/tuple b/libcxx/include/experimental/tuple
new file mode 100644
index 0000000..50d1e05
--- /dev/null
+++ b/libcxx/include/experimental/tuple

@@ -0,0 +1,81 @@
+// -*- C++ -*-
+//===----------------------------- tuple ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_EXPERIMENTAL_TUPLE
+#define _LIBCPP_EXPERIMENTAL_TUPLE
+
+/*
+    experimental/tuple synopsis
+
+// C++1y
+
+#include <tuple>
+
+namespace std {
+namespace experimental {
+inline namespace fundamentals_v1 {
+
+  // See C++14 20.4.2.5, tuple helper classes
+  template <class T> constexpr size_t tuple_size_v
+    = tuple_size<T>::value;
+
+  // 3.2.2, Calling a function with a tuple of arguments
+  template <class F, class Tuple>
+  constexpr decltype(auto) apply(F&& f, Tuple&& t);
+
+} // namespace fundamentals_v1
+} // namespace experimental
+} // namespace std
+
+ */
+
+# include <experimental/__config>
+
+#if _LIBCPP_STD_VER > 11
+
+# include <tuple>
+# include <utility>
+# include <__functional_base>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_LFTS
+
+#ifndef _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
+template <class _Tp>
+_LIBCPP_CONSTEXPR size_t tuple_size_v = tuple_size<_Tp>::value;
+#endif
+
+template <class _Fn, class _Tuple, size_t ..._Id>
+inline _LIBCPP_INLINE_VISIBILITY
+decltype(auto) __apply_tuple_impl(_Fn && __f, _Tuple && __t,
+                                  integer_sequence<size_t, _Id...>) {
+    return _VSTD::__invoke(
+        _VSTD::forward<_Fn>(__f),
+        _VSTD::get<_Id>(_VSTD::forward<_Tuple>(__t))...
+    );
+}
+
+template <class _Fn, class _Tuple>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+decltype(auto) apply(_Fn && __f, _Tuple && __t) {
+    return _VSTD_LFTS::__apply_tuple_impl(
+        _VSTD::forward<_Fn>(__f), _VSTD::forward<_Tuple>(__t),
+        make_index_sequence<tuple_size<typename decay<_Tuple>::type>::value>()
+    );
+}
+
+_LIBCPP_END_NAMESPACE_LFTS
+
+#endif /* _LIBCPP_STD_VER > 11 */
+
+#endif /* _LIBCPP_EXPERIMENTAL_TUPLE */

diff --git a/libcxx/include/experimental/type_traits b/libcxx/include/experimental/type_traits
new file mode 100644
index 0000000..ae49fc1
--- /dev/null
+++ b/libcxx/include/experimental/type_traits

@@ -0,0 +1,427 @@
+// -*- C++ -*-
+//===-------------------------- type_traits -------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_EXPERIMENTAL_TYPE_TRAITS
+#define _LIBCPP_EXPERIMENTAL_TYPE_TRAITS
+
+/**
+    experimental/type_traits synopsis
+
+// C++1y
+#include <type_traits>
+
+namespace std {
+namespace experimental {
+inline namespace fundamentals_v1 {
+
+  // See C++14 20.10.4.1, primary type categories
+  template <class T> constexpr bool is_void_v
+    = is_void<T>::value;
+  template <class T> constexpr bool is_null_pointer_v
+    = is_null_pointer<T>::value;
+  template <class T> constexpr bool is_integral_v
+    = is_integral<T>::value;
+  template <class T> constexpr bool is_floating_point_v
+    = is_floating_point<T>::value;
+  template <class T> constexpr bool is_array_v
+    = is_array<T>::value;
+  template <class T> constexpr bool is_pointer_v
+    = is_pointer<T>::value;
+  template <class T> constexpr bool is_lvalue_reference_v
+    = is_lvalue_reference<T>::value;
+  template <class T> constexpr bool is_rvalue_reference_v
+    = is_rvalue_reference<T>::value;
+  template <class T> constexpr bool is_member_object_pointer_v
+    = is_member_object_pointer<T>::value;
+  template <class T> constexpr bool is_member_function_pointer_v
+    = is_member_function_pointer<T>::value;
+  template <class T> constexpr bool is_enum_v
+    = is_enum<T>::value;
+  template <class T> constexpr bool is_union_v
+    = is_union<T>::value;
+  template <class T> constexpr bool is_class_v
+    = is_class<T>::value;
+  template <class T> constexpr bool is_function_v
+    = is_function<T>::value;
+
+  // See C++14 20.10.4.2, composite type categories
+  template <class T> constexpr bool is_reference_v
+    = is_reference<T>::value;
+  template <class T> constexpr bool is_arithmetic_v
+    = is_arithmetic<T>::value;
+  template <class T> constexpr bool is_fundamental_v
+    = is_fundamental<T>::value;
+  template <class T> constexpr bool is_object_v
+    = is_object<T>::value;
+  template <class T> constexpr bool is_scalar_v
+    = is_scalar<T>::value;
+  template <class T> constexpr bool is_compound_v
+    = is_compound<T>::value;
+  template <class T> constexpr bool is_member_pointer_v
+    = is_member_pointer<T>::value;
+
+  // See C++14 20.10.4.3, type properties
+  template <class T> constexpr bool is_const_v
+    = is_const<T>::value;
+  template <class T> constexpr bool is_volatile_v
+    = is_volatile<T>::value;
+  template <class T> constexpr bool is_trivial_v
+    = is_trivial<T>::value;
+  template <class T> constexpr bool is_trivially_copyable_v
+    = is_trivially_copyable<T>::value;
+  template <class T> constexpr bool is_standard_layout_v
+    = is_standard_layout<T>::value;
+  template <class T> constexpr bool is_pod_v
+    = is_pod<T>::value;
+  template <class T> constexpr bool is_literal_type_v
+    = is_literal_type<T>::value;
+  template <class T> constexpr bool is_empty_v
+    = is_empty<T>::value;
+  template <class T> constexpr bool is_polymorphic_v
+    = is_polymorphic<T>::value;
+  template <class T> constexpr bool is_abstract_v
+    = is_abstract<T>::value;
+  template <class T> constexpr bool is_final_v
+    = is_final<T>::value;
+  template <class T> constexpr bool is_signed_v
+    = is_signed<T>::value;
+  template <class T> constexpr bool is_unsigned_v
+    = is_unsigned<T>::value;
+  template <class T, class... Args> constexpr bool is_constructible_v
+    = is_constructible<T, Args...>::value;
+  template <class T> constexpr bool is_default_constructible_v
+    = is_default_constructible<T>::value;
+  template <class T> constexpr bool is_copy_constructible_v
+    = is_copy_constructible<T>::value;
+  template <class T> constexpr bool is_move_constructible_v
+    = is_move_constructible<T>::value;
+  template <class T, class U> constexpr bool is_assignable_v
+    = is_assignable<T, U>::value;
+  template <class T> constexpr bool is_copy_assignable_v
+    = is_copy_assignable<T>::value;
+  template <class T> constexpr bool is_move_assignable_v
+    = is_move_assignable<T>::value;
+  template <class T> constexpr bool is_destructible_v
+    = is_destructible<T>::value;
+  template <class T, class... Args> constexpr bool is_trivially_constructible_v
+    = is_trivially_constructible<T, Args...>::value;
+  template <class T> constexpr bool is_trivially_default_constructible_v
+    = is_trivially_default_constructible<T>::value;
+  template <class T> constexpr bool is_trivially_copy_constructible_v
+    = is_trivially_copy_constructible<T>::value;
+  template <class T> constexpr bool is_trivially_move_constructible_v
+    = is_trivially_move_constructible<T>::value;
+  template <class T, class U> constexpr bool is_trivially_assignable_v
+    = is_trivially_assignable<T, U>::value;
+  template <class T> constexpr bool is_trivially_copy_assignable_v
+    = is_trivially_copy_assignable<T>::value;
+  template <class T> constexpr bool is_trivially_move_assignable_v
+    = is_trivially_move_assignable<T>::value;
+  template <class T> constexpr bool is_trivially_destructible_v
+    = is_trivially_destructible<T>::value;
+  template <class T, class... Args> constexpr bool is_nothrow_constructible_v
+    = is_nothrow_constructible<T, Args...>::value;
+  template <class T> constexpr bool is_nothrow_default_constructible_v
+    = is_nothrow_default_constructible<T>::value;
+  template <class T> constexpr bool is_nothrow_copy_constructible_v
+    = is_nothrow_copy_constructible<T>::value;
+  template <class T> constexpr bool is_nothrow_move_constructible_v
+    = is_nothrow_move_constructible<T>::value;
+  template <class T, class U> constexpr bool is_nothrow_assignable_v
+    = is_nothrow_assignable<T, U>::value;
+  template <class T> constexpr bool is_nothrow_copy_assignable_v
+    = is_nothrow_copy_assignable<T>::value;
+  template <class T> constexpr bool is_nothrow_move_assignable_v
+    = is_nothrow_move_assignable<T>::value;
+  template <class T> constexpr bool is_nothrow_destructible_v
+    = is_nothrow_destructible<T>::value;
+  template <class T> constexpr bool has_virtual_destructor_v
+    = has_virtual_destructor<T>::value;
+
+  // See C++14 20.10.5, type property queries
+  template <class T> constexpr size_t alignment_of_v
+    = alignment_of<T>::value;
+  template <class T> constexpr size_t rank_v
+    = rank<T>::value;
+  template <class T, unsigned I = 0> constexpr size_t extent_v
+    = extent<T, I>::value;
+
+  // See C++14 20.10.6, type relations
+  template <class T, class U> constexpr bool is_same_v
+    = is_same<T, U>::value;
+  template <class Base, class Derived> constexpr bool is_base_of_v
+    = is_base_of<Base, Derived>::value;
+  template <class From, class To> constexpr bool is_convertible_v
+    = is_convertible<From, To>::value;
+
+  // 3.3.2, Other type transformations
+  template <class> class invocation_type; // not defined
+  template <class F, class... ArgTypes> class invocation_type<F(ArgTypes...)>;
+  template <class> class raw_invocation_type; // not defined
+  template <class F, class... ArgTypes> class raw_invocation_type<F(ArgTypes...)>;
+
+  template <class T>
+    using invocation_type_t = typename invocation_type<T>::type;
+  template <class T>
+    using raw_invocation_type_t = typename raw_invocation_type<T>::type;
+
+} // namespace fundamentals_v1
+} // namespace experimental
+} // namespace std
+
+ */
+
+#include <experimental/__config>
+
+#if _LIBCPP_STD_VER > 11
+
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_LFTS
+
+#ifndef _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
+
+// C++14 20.10.4.1, primary type categories
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_void_v
+    = is_void<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_null_pointer_v
+    = is_null_pointer<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_integral_v
+    = is_integral<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_floating_point_v
+    = is_floating_point<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_array_v
+    = is_array<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_pointer_v
+    = is_pointer<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_lvalue_reference_v
+    = is_lvalue_reference<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_rvalue_reference_v
+    = is_rvalue_reference<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_member_object_pointer_v
+    = is_member_object_pointer<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_member_function_pointer_v
+    = is_member_function_pointer<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_enum_v
+    = is_enum<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_union_v
+    = is_union<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_class_v
+    = is_class<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_function_v
+    = is_function<_Tp>::value;
+
+// C++14 20.10.4.2,  composite type categories
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_reference_v
+    = is_reference<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_arithmetic_v
+    = is_arithmetic<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_fundamental_v
+    = is_fundamental<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_object_v
+    = is_object<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_scalar_v
+    = is_scalar<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_compound_v
+    = is_compound<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_member_pointer_v
+    = is_member_pointer<_Tp>::value;
+
+// C++14 20.10.4.3, type properties
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_const_v
+    = is_const<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_volatile_v
+    = is_volatile<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_trivial_v
+    = is_trivial<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_trivially_copyable_v
+    = is_trivially_copyable<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_standard_layout_v
+    = is_standard_layout<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_pod_v
+    = is_pod<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_literal_type_v
+    = is_literal_type<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_empty_v
+    = is_empty<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_polymorphic_v
+    = is_polymorphic<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_abstract_v
+    = is_abstract<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_final_v
+    = is_final<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_signed_v
+    = is_signed<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_unsigned_v
+    = is_unsigned<_Tp>::value;
+
+template <class _Tp, class ..._Ts> _LIBCPP_CONSTEXPR bool is_constructible_v
+    = is_constructible<_Tp, _Ts...>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_default_constructible_v
+    = is_default_constructible<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_copy_constructible_v
+    = is_copy_constructible<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_move_constructible_v
+    = is_move_constructible<_Tp>::value;
+
+template <class _Tp, class _Up> _LIBCPP_CONSTEXPR bool is_assignable_v
+    = is_assignable<_Tp, _Up>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_copy_assignable_v
+    = is_copy_assignable<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_move_assignable_v
+    = is_move_assignable<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_destructible_v
+    = is_destructible<_Tp>::value;
+
+template <class _Tp, class ..._Ts> _LIBCPP_CONSTEXPR bool is_trivially_constructible_v
+    = is_trivially_constructible<_Tp, _Ts...>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_trivially_default_constructible_v
+    = is_trivially_default_constructible<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_trivially_copy_constructible_v
+    = is_trivially_copy_constructible<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_trivially_move_constructible_v
+    = is_trivially_move_constructible<_Tp>::value;
+
+template <class _Tp, class _Up> _LIBCPP_CONSTEXPR bool is_trivially_assignable_v
+    = is_trivially_assignable<_Tp, _Up>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_trivially_copy_assignable_v
+    = is_trivially_copy_assignable<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_trivially_move_assignable_v
+    = is_trivially_move_assignable<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_trivially_destructible_v
+    = is_trivially_destructible<_Tp>::value;
+
+template <class _Tp, class ..._Ts> _LIBCPP_CONSTEXPR bool is_nothrow_constructible_v
+    = is_nothrow_constructible<_Tp, _Ts...>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_nothrow_default_constructible_v
+    = is_nothrow_default_constructible<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_nothrow_copy_constructible_v
+    = is_nothrow_copy_constructible<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_nothrow_move_constructible_v
+    = is_nothrow_move_constructible<_Tp>::value;
+
+template <class _Tp, class _Up> _LIBCPP_CONSTEXPR bool is_nothrow_assignable_v
+    = is_nothrow_assignable<_Tp, _Up>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_nothrow_copy_assignable_v
+    = is_nothrow_copy_assignable<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_nothrow_move_assignable_v
+    = is_nothrow_move_assignable<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool is_nothrow_destructible_v
+    = is_nothrow_destructible<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR bool has_virtual_destructor_v
+    = has_virtual_destructor<_Tp>::value;
+
+// C++14 20.10.5, type properties queries
+
+template <class _Tp> _LIBCPP_CONSTEXPR size_t alignment_of_v
+    = alignment_of<_Tp>::value;
+
+template <class _Tp> _LIBCPP_CONSTEXPR size_t rank_v
+    = rank<_Tp>::value;
+
+template <class _Tp, unsigned _Id = 0> _LIBCPP_CONSTEXPR size_t extent_v
+    = extent<_Tp, _Id>::value;
+
+// C++14 20.10.6, type relations
+
+template <class _Tp, class _Up> _LIBCPP_CONSTEXPR bool is_same_v
+    = is_same<_Tp, _Up>::value;
+
+template <class _Tp, class _Up> _LIBCPP_CONSTEXPR bool is_base_of_v
+    = is_base_of<_Tp, _Up>::value;
+
+template <class _Tp, class _Up> _LIBCPP_CONSTEXPR bool is_convertible_v
+    = is_convertible<_Tp, _Up>::value;
+
+#endif /* _LIBCPP_HAS_NO_VARIABLE_TEMPLATES */
+
+// 3.3.2, Other type transformations
+/*
+template <class>
+class _LIBCPP_TYPE_VIS_ONLY raw_invocation_type;
+
+template <class _Fn, class ..._Args>
+class _LIBCPP_TYPE_VIS_ONLY raw_invocation_type<_Fn(_Args...)>;
+
+template <class>
+class _LIBCPP_TYPE_VIS_ONLY invokation_type;
+
+template <class _Fn, class ..._Args>
+class _LIBCPP_TYPE_VIS_ONLY invokation_type<_Fn(_Args...)>;
+
+template <class _Tp>
+using invokation_type_t = typename invokation_type<_Tp>::type;
+
+template <class _Tp>
+using raw_invocation_type_t = typename raw_invocation_type<_Tp>::type;
+*/
+
+_LIBCPP_END_NAMESPACE_LFTS
+
+#endif /* _LIBCPP_STD_VER > 11 */
+
+#endif /* _LIBCPP_EXPERIMENTAL_TYPE_TRAITS */

diff --git a/libcxx/include/experimental/utility b/libcxx/include/experimental/utility
new file mode 100644
index 0000000..b5fca6c
--- /dev/null
+++ b/libcxx/include/experimental/utility

@@ -0,0 +1,47 @@
+// -*- C++ -*-
+//===-------------------------- utility ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_EXPERIMENTAL_UTILITY
+#define _LIBCPP_EXPERIMENTAL_UTILITY
+
+/*
+    experimental/utility synopsis
+
+// C++1y
+
+#include <utility>
+
+namespace std {
+namespace experimental {
+inline namespace fundamentals_v1 {
+
+  3.1.2, erased-type placeholder
+  struct erased_type { };
+
+} // namespace fundamentals_v1
+} // namespace experimental
+} // namespace std
+
+ */
+
+#include <experimental/__config>
+#include <utility>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_LFTS
+
+  struct _LIBCPP_TYPE_VIS_ONLY erased_type { };
+
+_LIBCPP_END_NAMESPACE_LFTS
+
+#endif /* _LIBCPP_EXPERIMENTAL_UTILITY */

diff --git a/libcxx/include/ext/__hash b/libcxx/include/ext/__hash
new file mode 100644
index 0000000..5675d54
--- /dev/null
+++ b/libcxx/include/ext/__hash

@@ -0,0 +1,135 @@
+// -*- C++ -*-
+//===------------------------- hash_set ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_EXT_HASH
+#define _LIBCPP_EXT_HASH
+
+#pragma GCC system_header
+
+#include <string>
+#include <cstring>
+
+namespace __gnu_cxx {
+using namespace std;
+
+template <typename _Tp> struct _LIBCPP_TYPE_VIS_ONLY hash { };
+
+template <> struct _LIBCPP_TYPE_VIS_ONLY hash<const char*>
+    : public unary_function<const char*, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(const char *__c) const _NOEXCEPT
+    {
+        return __do_string_hash(__c, __c + strlen(__c));
+    }
+};
+
+template <> struct _LIBCPP_TYPE_VIS_ONLY hash<char *>
+    : public unary_function<char*, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(char *__c) const _NOEXCEPT
+    {
+        return __do_string_hash<const char *>(__c, __c + strlen(__c));
+    }
+};
+
+template <> struct _LIBCPP_TYPE_VIS_ONLY hash<char>
+    : public unary_function<char, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(char __c) const _NOEXCEPT
+    {
+        return __c;
+    }
+};
+
+template <> struct _LIBCPP_TYPE_VIS_ONLY hash<signed char>
+    : public unary_function<signed char, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(signed char __c) const _NOEXCEPT
+    {
+        return __c;
+    }
+};
+
+template <> struct _LIBCPP_TYPE_VIS_ONLY hash<unsigned char>
+    : public unary_function<unsigned char, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(unsigned char __c) const _NOEXCEPT
+    {
+        return __c;
+    }
+};
+
+template <> struct _LIBCPP_TYPE_VIS_ONLY hash<short>
+    : public unary_function<short, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(short __c) const _NOEXCEPT
+    {
+        return __c;
+    }
+};
+
+template <> struct _LIBCPP_TYPE_VIS_ONLY hash<unsigned short>
+    : public unary_function<unsigned short, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(unsigned short __c) const _NOEXCEPT
+    {
+        return __c;
+    }
+};
+
+template <> struct _LIBCPP_TYPE_VIS_ONLY hash<int>
+    : public unary_function<int, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(int __c) const _NOEXCEPT
+    {
+        return __c;
+    }
+};
+
+template <> struct _LIBCPP_TYPE_VIS_ONLY hash<unsigned int>
+    : public unary_function<unsigned int, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(unsigned int __c) const _NOEXCEPT
+    {
+        return __c;
+    }
+};
+
+template <> struct _LIBCPP_TYPE_VIS_ONLY hash<long>
+    : public unary_function<long, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(long __c) const _NOEXCEPT
+    {
+        return __c;
+    }
+};
+
+template <> struct _LIBCPP_TYPE_VIS_ONLY hash<unsigned long>
+    : public unary_function<unsigned long, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(unsigned long __c) const _NOEXCEPT
+    {
+        return __c;
+    }
+};
+}
+
+#endif  // _LIBCPP_EXT_HASH

diff --git a/libcxx/include/ext/hash_map b/libcxx/include/ext/hash_map
new file mode 100644
index 0000000..31fcedf
--- /dev/null
+++ b/libcxx/include/ext/hash_map

@@ -0,0 +1,994 @@
+// -*- C++ -*-
+//===-------------------------- hash_map ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_HASH_MAP
+#define _LIBCPP_HASH_MAP
+
+/*
+
+    hash_map synopsis
+
+namespace __gnu_cxx
+{
+
+template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
+          class Alloc = allocator<pair<const Key, T>>>
+class hash_map
+{
+public:
+    // types
+    typedef Key                                                        key_type;
+    typedef T                                                          mapped_type;
+    typedef Hash                                                       hasher;
+    typedef Pred                                                       key_equal;
+    typedef Alloc                                                      allocator_type;
+    typedef pair<const key_type, mapped_type>                          value_type;
+    typedef value_type&                                                reference;
+    typedef const value_type&                                          const_reference;
+    typedef typename allocator_traits<allocator_type>::pointer         pointer;
+    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
+    typedef typename allocator_traits<allocator_type>::size_type       size_type;
+    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
+
+    typedef /unspecified/ iterator;
+    typedef /unspecified/ const_iterator;
+
+    explicit hash_map(size_type n = 193, const hasher& hf = hasher(),
+                           const key_equal& eql = key_equal(),
+                           const allocator_type& a = allocator_type());
+    template <class InputIterator>
+        hash_map(InputIterator f, InputIterator l,
+                      size_type n = 193, const hasher& hf = hasher(),
+                      const key_equal& eql = key_equal(),
+                      const allocator_type& a = allocator_type());
+    hash_map(const hash_map&);
+    ~hash_map();
+    hash_map& operator=(const hash_map&);
+
+    allocator_type get_allocator() const;
+
+    bool      empty() const;
+    size_type size() const;
+    size_type max_size() const;
+
+    iterator       begin();
+    iterator       end();
+    const_iterator begin()  const;
+    const_iterator end()    const;
+
+    pair<iterator, bool> insert(const value_type& obj);
+    template <class InputIterator>
+        void insert(InputIterator first, InputIterator last);
+
+    void erase(const_iterator position);
+    size_type erase(const key_type& k);
+    void erase(const_iterator first, const_iterator last);
+    void clear();
+
+    void swap(hash_map&);
+
+    hasher hash_funct() const;
+    key_equal key_eq() const;
+
+    iterator       find(const key_type& k);
+    const_iterator find(const key_type& k) const;
+    size_type count(const key_type& k) const;
+    pair<iterator, iterator>             equal_range(const key_type& k);
+    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
+
+    mapped_type& operator[](const key_type& k);
+
+    size_type bucket_count() const;
+    size_type max_bucket_count() const;
+
+    size_type elems_in_bucket(size_type n) const;
+
+    void resize(size_type n);
+};
+
+template <class Key, class T, class Hash, class Pred, class Alloc>
+    void swap(hash_map<Key, T, Hash, Pred, Alloc>& x,
+              hash_map<Key, T, Hash, Pred, Alloc>& y);
+
+template <class Key, class T, class Hash, class Pred, class Alloc>
+    bool
+    operator==(const hash_map<Key, T, Hash, Pred, Alloc>& x,
+               const hash_map<Key, T, Hash, Pred, Alloc>& y);
+
+template <class Key, class T, class Hash, class Pred, class Alloc>
+    bool
+    operator!=(const hash_map<Key, T, Hash, Pred, Alloc>& x,
+               const hash_map<Key, T, Hash, Pred, Alloc>& y);
+
+template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
+          class Alloc = allocator<pair<const Key, T>>>
+class hash_multimap
+{
+public:
+    // types
+    typedef Key                                                        key_type;
+    typedef T                                                          mapped_type;
+    typedef Hash                                                       hasher;
+    typedef Pred                                                       key_equal;
+    typedef Alloc                                                      allocator_type;
+    typedef pair<const key_type, mapped_type>                          value_type;
+    typedef value_type&                                                reference;
+    typedef const value_type&                                          const_reference;
+    typedef typename allocator_traits<allocator_type>::pointer         pointer;
+    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
+    typedef typename allocator_traits<allocator_type>::size_type       size_type;
+    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
+
+    typedef /unspecified/ iterator;
+    typedef /unspecified/ const_iterator;
+
+    explicit hash_multimap(size_type n = 193, const hasher& hf = hasher(),
+                           const key_equal& eql = key_equal(),
+                           const allocator_type& a = allocator_type());
+    template <class InputIterator>
+        hash_multimap(InputIterator f, InputIterator l,
+                      size_type n = 193, const hasher& hf = hasher(),
+                      const key_equal& eql = key_equal(),
+                      const allocator_type& a = allocator_type());
+    explicit hash_multimap(const allocator_type&);
+    hash_multimap(const hash_multimap&);
+    ~hash_multimap();
+    hash_multimap& operator=(const hash_multimap&);
+
+    allocator_type get_allocator() const;
+
+    bool      empty() const;
+    size_type size() const;
+    size_type max_size() const;
+
+    iterator       begin();
+    iterator       end();
+    const_iterator begin()  const;
+    const_iterator end()    const;
+
+    iterator insert(const value_type& obj);
+    template <class InputIterator>
+        void insert(InputIterator first, InputIterator last);
+
+    void erase(const_iterator position);
+    size_type erase(const key_type& k);
+    void erase(const_iterator first, const_iterator last);
+    void clear();
+
+    void swap(hash_multimap&);
+
+    hasher hash_funct() const;
+    key_equal key_eq() const;
+
+    iterator       find(const key_type& k);
+    const_iterator find(const key_type& k) const;
+    size_type count(const key_type& k) const;
+    pair<iterator, iterator>             equal_range(const key_type& k);
+    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
+
+    size_type bucket_count() const;
+    size_type max_bucket_count() const;
+
+    size_type elems_in_bucket(size_type n) const;
+
+    void resize(size_type n);
+};
+
+template <class Key, class T, class Hash, class Pred, class Alloc>
+    void swap(hash_multimap<Key, T, Hash, Pred, Alloc>& x,
+              hash_multimap<Key, T, Hash, Pred, Alloc>& y);
+
+template <class Key, class T, class Hash, class Pred, class Alloc>
+    bool
+    operator==(const hash_multimap<Key, T, Hash, Pred, Alloc>& x,
+               const hash_multimap<Key, T, Hash, Pred, Alloc>& y);
+
+template <class Key, class T, class Hash, class Pred, class Alloc>
+    bool
+    operator!=(const hash_multimap<Key, T, Hash, Pred, Alloc>& x,
+               const hash_multimap<Key, T, Hash, Pred, Alloc>& y);
+
+}  // __gnu_cxx
+
+*/
+
+#include <__config>
+#include <__hash_table>
+#include <functional>
+#include <stdexcept>
+#include <type_traits>
+#include <ext/__hash>
+
+#if __DEPRECATED
+#if defined(_MSC_VER) && ! defined(__clang__)
+    _LIBCPP_WARNING("Use of the header <ext/hash_map> is deprecated.  Migrate to <unordered_map>")
+#else
+#   warning Use of the header <ext/hash_map> is deprecated.  Migrate to <unordered_map>
+#endif
+#endif
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+namespace __gnu_cxx {
+
+using namespace std;
+
+template <class _Tp, class _Hash,
+          bool = is_empty<_Hash>::value && !__libcpp_is_final<_Hash>::value
+        >
+class __hash_map_hasher
+    : private _Hash
+{
+public:
+    _LIBCPP_INLINE_VISIBILITY __hash_map_hasher() : _Hash() {}
+    _LIBCPP_INLINE_VISIBILITY __hash_map_hasher(const _Hash& __h) : _Hash(__h) {}
+    _LIBCPP_INLINE_VISIBILITY const _Hash& hash_function() const {return *this;}
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(const _Tp& __x) const
+        {return static_cast<const _Hash&>(*this)(__x.first);}
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(const typename _Tp::first_type& __x) const
+        {return static_cast<const _Hash&>(*this)(__x);}
+};
+
+template <class _Tp, class _Hash>
+class __hash_map_hasher<_Tp, _Hash, false>
+{
+    _Hash __hash_;
+public:
+    _LIBCPP_INLINE_VISIBILITY __hash_map_hasher() : __hash_() {}
+    _LIBCPP_INLINE_VISIBILITY __hash_map_hasher(const _Hash& __h) : __hash_(__h) {}
+    _LIBCPP_INLINE_VISIBILITY const _Hash& hash_function() const {return __hash_;}
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(const _Tp& __x) const
+        {return __hash_(__x.first);}
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(const typename _Tp::first_type& __x) const
+        {return __hash_(__x);}
+};
+
+template <class _Tp, class _Pred,
+          bool = is_empty<_Pred>::value && !__libcpp_is_final<_Pred>::value
+         >
+class __hash_map_equal
+    : private _Pred
+{
+public:
+    _LIBCPP_INLINE_VISIBILITY __hash_map_equal() : _Pred() {}
+    _LIBCPP_INLINE_VISIBILITY __hash_map_equal(const _Pred& __p) : _Pred(__p) {}
+    _LIBCPP_INLINE_VISIBILITY const _Pred& key_eq() const {return *this;}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _Tp& __x, const _Tp& __y) const
+        {return static_cast<const _Pred&>(*this)(__x.first, __y.first);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const typename _Tp::first_type& __x, const _Tp& __y) const
+        {return static_cast<const _Pred&>(*this)(__x, __y.first);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _Tp& __x, const typename _Tp::first_type& __y) const
+        {return static_cast<const _Pred&>(*this)(__x.first, __y);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const typename _Tp::first_type& __x,
+                    const typename _Tp::first_type& __y) const
+        {return static_cast<const _Pred&>(*this)(__x, __y);}
+};
+
+template <class _Tp, class _Pred>
+class __hash_map_equal<_Tp, _Pred, false>
+{
+    _Pred __pred_;
+public:
+    _LIBCPP_INLINE_VISIBILITY __hash_map_equal() : __pred_() {}
+    _LIBCPP_INLINE_VISIBILITY __hash_map_equal(const _Pred& __p) : __pred_(__p) {}
+    _LIBCPP_INLINE_VISIBILITY const _Pred& key_eq() const {return __pred_;}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _Tp& __x, const _Tp& __y) const
+        {return __pred_(__x.first, __y.first);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const typename _Tp::first_type& __x, const _Tp& __y) const
+        {return __pred_(__x, __y.first);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _Tp& __x, const typename _Tp::first_type& __y) const
+        {return __pred_(__x.first, __y);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const typename _Tp::first_type& __x,
+                    const typename _Tp::first_type& __y) const
+        {return __pred_(__x, __y);}
+};
+
+template <class _Alloc>
+class __hash_map_node_destructor
+{
+    typedef _Alloc                              allocator_type;
+    typedef allocator_traits<allocator_type>    __alloc_traits;
+    typedef typename __alloc_traits::value_type::value_type value_type;
+public:
+    typedef typename __alloc_traits::pointer    pointer;
+private:
+    typedef typename value_type::first_type     first_type;
+    typedef typename value_type::second_type    second_type;
+
+    allocator_type& __na_;
+
+    __hash_map_node_destructor& operator=(const __hash_map_node_destructor&);
+
+public:
+    bool __first_constructed;
+    bool __second_constructed;
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __hash_map_node_destructor(allocator_type& __na)
+        : __na_(__na),
+          __first_constructed(false),
+          __second_constructed(false)
+        {}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_map_node_destructor(__hash_node_destructor<allocator_type>&& __x)
+        : __na_(__x.__na_),
+          __first_constructed(__x.__value_constructed),
+          __second_constructed(__x.__value_constructed)
+        {
+            __x.__value_constructed = false;
+        }
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_map_node_destructor(const __hash_node_destructor<allocator_type>& __x)
+        : __na_(__x.__na_),
+          __first_constructed(__x.__value_constructed),
+          __second_constructed(__x.__value_constructed)
+        {
+            const_cast<bool&>(__x.__value_constructed) = false;
+        }
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY
+    void operator()(pointer __p)
+    {
+        if (__second_constructed)
+            __alloc_traits::destroy(__na_, _VSTD::addressof(__p->__value_.second));
+        if (__first_constructed)
+            __alloc_traits::destroy(__na_, _VSTD::addressof(__p->__value_.first));
+        if (__p)
+            __alloc_traits::deallocate(__na_, __p, 1);
+    }
+};
+
+template <class _HashIterator>
+class _LIBCPP_TYPE_VIS_ONLY __hash_map_iterator
+{
+    _HashIterator __i_;
+
+    typedef pointer_traits<typename _HashIterator::pointer>      __pointer_traits;
+    typedef const typename _HashIterator::value_type::first_type key_type;
+    typedef typename _HashIterator::value_type::second_type      mapped_type;
+public:
+    typedef forward_iterator_tag                                 iterator_category;
+    typedef pair<key_type, mapped_type>                          value_type;
+    typedef typename _HashIterator::difference_type              difference_type;
+    typedef value_type&                                          reference;
+    typedef typename __pointer_traits::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<value_type>
+#else
+            rebind<value_type>::other
+#endif
+                                                                 pointer;
+
+    _LIBCPP_INLINE_VISIBILITY __hash_map_iterator() {}
+
+    _LIBCPP_INLINE_VISIBILITY __hash_map_iterator(_HashIterator __i) : __i_(__i) {}
+
+    _LIBCPP_INLINE_VISIBILITY reference operator*() const {return *operator->();}
+    _LIBCPP_INLINE_VISIBILITY pointer operator->() const {return (pointer)__i_.operator->();}
+
+    _LIBCPP_INLINE_VISIBILITY __hash_map_iterator& operator++() {++__i_; return *this;}
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_map_iterator operator++(int)
+    {
+        __hash_map_iterator __t(*this);
+        ++(*this);
+        return __t;
+    }
+
+    friend _LIBCPP_INLINE_VISIBILITY 
+    bool operator==(const __hash_map_iterator& __x, const __hash_map_iterator& __y)
+        {return __x.__i_ == __y.__i_;}
+    friend _LIBCPP_INLINE_VISIBILITY 
+    bool operator!=(const __hash_map_iterator& __x, const __hash_map_iterator& __y)
+        {return __x.__i_ != __y.__i_;}
+
+    template <class, class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY hash_map;
+    template <class, class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY hash_multimap;
+    template <class> friend class _LIBCPP_TYPE_VIS_ONLY __hash_const_iterator;
+    template <class> friend class _LIBCPP_TYPE_VIS_ONLY __hash_const_local_iterator;
+    template <class> friend class _LIBCPP_TYPE_VIS_ONLY __hash_map_const_iterator;
+};
+
+template <class _HashIterator>
+class _LIBCPP_TYPE_VIS_ONLY __hash_map_const_iterator
+{
+    _HashIterator __i_;
+
+    typedef pointer_traits<typename _HashIterator::pointer>      __pointer_traits;
+    typedef const typename _HashIterator::value_type::first_type key_type;
+    typedef typename _HashIterator::value_type::second_type      mapped_type;
+public:
+    typedef forward_iterator_tag                                 iterator_category;
+    typedef pair<key_type, mapped_type>                          value_type;
+    typedef typename _HashIterator::difference_type              difference_type;
+    typedef const value_type&                                    reference;
+    typedef typename __pointer_traits::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<const value_type>
+#else
+            rebind<const value_type>::other
+#endif
+                                                                 pointer;
+
+    _LIBCPP_INLINE_VISIBILITY __hash_map_const_iterator() {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_map_const_iterator(_HashIterator __i) : __i_(__i) {}
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_map_const_iterator(
+            __hash_map_iterator<typename _HashIterator::__non_const_iterator> __i)
+                : __i_(__i.__i_) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    reference operator*() const {return *operator->();}
+    _LIBCPP_INLINE_VISIBILITY
+    pointer operator->() const {return (pointer)__i_.operator->();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_map_const_iterator& operator++() {++__i_; return *this;}
+    _LIBCPP_INLINE_VISIBILITY
+    __hash_map_const_iterator operator++(int)
+    {
+        __hash_map_const_iterator __t(*this);
+        ++(*this);
+        return __t;
+    }
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator==(const __hash_map_const_iterator& __x, const __hash_map_const_iterator& __y)
+        {return __x.__i_ == __y.__i_;}
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(const __hash_map_const_iterator& __x, const __hash_map_const_iterator& __y)
+        {return __x.__i_ != __y.__i_;}
+
+    template <class, class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY hash_map;
+    template <class, class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY hash_multimap;
+    template <class> friend class _LIBCPP_TYPE_VIS_ONLY __hash_const_iterator;
+    template <class> friend class _LIBCPP_TYPE_VIS_ONLY __hash_const_local_iterator;
+};
+
+template <class _Key, class _Tp, class _Hash = hash<_Key>, class _Pred = equal_to<_Key>,
+          class _Alloc = allocator<pair<const _Key, _Tp> > >
+class _LIBCPP_TYPE_VIS_ONLY hash_map
+{
+public:
+    // types
+    typedef _Key                                           key_type;
+    typedef _Tp                                            mapped_type;
+    typedef _Tp                                            data_type;
+    typedef _Hash                                          hasher;
+    typedef _Pred                                          key_equal;
+    typedef _Alloc                                         allocator_type;
+    typedef pair<const key_type, mapped_type>              value_type;
+    typedef value_type&                                    reference;
+    typedef const value_type&                              const_reference;
+
+private:
+    typedef pair<key_type, mapped_type>                    __value_type;
+    typedef __hash_map_hasher<__value_type, hasher>   __hasher;
+    typedef __hash_map_equal<__value_type, key_equal> __key_equal;
+    typedef typename __rebind_alloc_helper<allocator_traits<allocator_type>, __value_type>::type __allocator_type;
+
+    typedef __hash_table<__value_type, __hasher,
+                         __key_equal,  __allocator_type>   __table;
+
+    __table __table_;
+
+    typedef typename __table::__node_pointer               __node_pointer;
+    typedef typename __table::__node_const_pointer         __node_const_pointer;
+    typedef typename __table::__node_traits                __node_traits;
+    typedef typename __table::__node_allocator             __node_allocator;
+    typedef typename __table::__node                       __node;
+    typedef __hash_map_node_destructor<__node_allocator>   _Dp;
+    typedef unique_ptr<__node, _Dp>                         __node_holder;
+    typedef allocator_traits<allocator_type>               __alloc_traits;
+public:
+    typedef typename __alloc_traits::pointer         pointer;
+    typedef typename __alloc_traits::const_pointer   const_pointer;
+    typedef typename __alloc_traits::size_type       size_type;
+    typedef typename __alloc_traits::difference_type difference_type;
+
+    typedef __hash_map_iterator<typename __table::iterator>       iterator;
+    typedef __hash_map_const_iterator<typename __table::const_iterator> const_iterator;
+
+    _LIBCPP_INLINE_VISIBILITY hash_map() {__table_.rehash(193);}
+    explicit hash_map(size_type __n, const hasher& __hf = hasher(),
+                           const key_equal& __eql = key_equal());
+    hash_map(size_type __n, const hasher& __hf,
+                  const key_equal& __eql,
+                  const allocator_type& __a);
+    template <class _InputIterator>
+        hash_map(_InputIterator __first, _InputIterator __last);
+    template <class _InputIterator>
+        hash_map(_InputIterator __first, _InputIterator __last,
+                      size_type __n, const hasher& __hf = hasher(),
+                      const key_equal& __eql = key_equal());
+    template <class _InputIterator>
+        hash_map(_InputIterator __first, _InputIterator __last,
+                      size_type __n, const hasher& __hf,
+                      const key_equal& __eql,
+                      const allocator_type& __a);
+    hash_map(const hash_map& __u);
+
+    _LIBCPP_INLINE_VISIBILITY
+    allocator_type get_allocator() const
+        {return allocator_type(__table_.__node_alloc());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool      empty() const {return __table_.size() == 0;}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type size() const  {return __table_.size();}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type max_size() const {return __table_.max_size();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       begin()        {return __table_.begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       end()          {return __table_.end();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator begin()  const {return __table_.begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator end()    const {return __table_.end();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    pair<iterator, bool> insert(const value_type& __x)
+        {return __table_.__insert_unique(__x);}
+    _LIBCPP_INLINE_VISIBILITY
+    iterator insert(const_iterator, const value_type& __x) {return insert(__x).first;}
+    template <class _InputIterator>
+        void insert(_InputIterator __first, _InputIterator __last);
+
+    _LIBCPP_INLINE_VISIBILITY
+    void erase(const_iterator __p) {__table_.erase(__p.__i_);}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type erase(const key_type& __k) {return __table_.__erase_unique(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    void erase(const_iterator __first, const_iterator __last)
+        {__table_.erase(__first.__i_, __last.__i_);}
+    _LIBCPP_INLINE_VISIBILITY
+    void clear() {__table_.clear();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(hash_map& __u) {__table_.swap(__u.__table_);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    hasher hash_funct() const
+        {return __table_.hash_function().hash_function();}
+    _LIBCPP_INLINE_VISIBILITY
+    key_equal key_eq() const
+        {return __table_.key_eq().key_eq();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       find(const key_type& __k)       {return __table_.find(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator find(const key_type& __k) const {return __table_.find(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type count(const key_type& __k) const {return __table_.__count_unique(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    pair<iterator, iterator>             equal_range(const key_type& __k)
+        {return __table_.__equal_range_unique(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
+        {return __table_.__equal_range_unique(__k);}
+
+    mapped_type& operator[](const key_type& __k);
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type bucket_count() const {return __table_.bucket_count();}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type max_bucket_count() const {return __table_.max_bucket_count();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type elems_in_bucket(size_type __n) const
+        {return __table_.bucket_size(__n);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void resize(size_type __n) {__table_.rehash(__n);}
+
+private:
+    __node_holder __construct_node(const key_type& __k);
+};
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_map(
+        size_type __n, const hasher& __hf, const key_equal& __eql)
+    : __table_(__hf, __eql)
+{
+    __table_.rehash(__n);
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_map(
+        size_type __n, const hasher& __hf, const key_equal& __eql,
+        const allocator_type& __a)
+    : __table_(__hf, __eql, __a)
+{
+    __table_.rehash(__n);
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+template <class _InputIterator>
+hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_map(
+        _InputIterator __first, _InputIterator __last)
+{
+    __table_.rehash(193);
+    insert(__first, __last);
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+template <class _InputIterator>
+hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_map(
+        _InputIterator __first, _InputIterator __last, size_type __n,
+        const hasher& __hf, const key_equal& __eql)
+    : __table_(__hf, __eql)
+{
+    __table_.rehash(__n);
+    insert(__first, __last);
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+template <class _InputIterator>
+hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_map(
+        _InputIterator __first, _InputIterator __last, size_type __n,
+        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
+    : __table_(__hf, __eql, __a)
+{
+    __table_.rehash(__n);
+    insert(__first, __last);
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_map(
+        const hash_map& __u)
+    : __table_(__u.__table_)
+{
+    __table_.rehash(__u.bucket_count());
+    insert(__u.begin(), __u.end());
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+typename hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder
+hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node(const key_type& __k)
+{
+    __node_allocator& __na = __table_.__node_alloc();
+    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_.first), __k);
+    __h.get_deleter().__first_constructed = true;
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_.second));
+    __h.get_deleter().__second_constructed = true;
+    return _VSTD::move(__h);  // explicitly moved for C++03
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+template <class _InputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::insert(_InputIterator __first,
+                                                       _InputIterator __last)
+{
+    for (; __first != __last; ++__first)
+        __table_.__insert_unique(*__first);
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+_Tp&
+hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator[](const key_type& __k)
+{
+    iterator __i = find(__k);
+    if (__i != end())
+        return __i->second;
+    __node_holder __h = __construct_node(__k);
+    pair<iterator, bool> __r = __table_.__node_insert_unique(__h.get());
+    __h.release();
+    return __r.first->second;
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
+     hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
+{
+    __x.swap(__y);
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+bool
+operator==(const hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
+           const hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
+{
+    if (__x.size() != __y.size())
+        return false;
+    typedef typename hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::const_iterator
+                                                                 const_iterator;
+    for (const_iterator __i = __x.begin(), __ex = __x.end(), __ey = __y.end();
+            __i != __ex; ++__i)
+    {
+        const_iterator __j = __y.find(__i->first);
+        if (__j == __ey || !(*__i == *__j))
+            return false;
+    }
+    return true;
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
+           const hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
+{
+    return !(__x == __y);
+}
+
+template <class _Key, class _Tp, class _Hash = hash<_Key>, class _Pred = equal_to<_Key>,
+          class _Alloc = allocator<pair<const _Key, _Tp> > >
+class _LIBCPP_TYPE_VIS_ONLY hash_multimap
+{
+public:
+    // types
+    typedef _Key                                           key_type;
+    typedef _Tp                                            mapped_type;
+    typedef _Tp                                            data_type;
+    typedef _Hash                                          hasher;
+    typedef _Pred                                          key_equal;
+    typedef _Alloc                                         allocator_type;
+    typedef pair<const key_type, mapped_type>              value_type;
+    typedef value_type&                                    reference;
+    typedef const value_type&                              const_reference;
+
+private:
+    typedef pair<key_type, mapped_type>                    __value_type;
+    typedef __hash_map_hasher<__value_type, hasher>   __hasher;
+    typedef __hash_map_equal<__value_type, key_equal> __key_equal;
+    typedef typename __rebind_alloc_helper<allocator_traits<allocator_type>, __value_type>::type __allocator_type;
+
+    typedef __hash_table<__value_type, __hasher,
+                         __key_equal,  __allocator_type>   __table;
+
+    __table __table_;
+
+    typedef typename __table::__node_traits                __node_traits;
+    typedef typename __table::__node_allocator             __node_allocator;
+    typedef typename __table::__node                       __node;
+    typedef __hash_map_node_destructor<__node_allocator>   _Dp;
+    typedef unique_ptr<__node, _Dp>                         __node_holder;
+    typedef allocator_traits<allocator_type>               __alloc_traits;
+public:
+    typedef typename __alloc_traits::pointer         pointer;
+    typedef typename __alloc_traits::const_pointer   const_pointer;
+    typedef typename __alloc_traits::size_type       size_type;
+    typedef typename __alloc_traits::difference_type difference_type;
+
+    typedef __hash_map_iterator<typename __table::iterator>       iterator;
+    typedef __hash_map_const_iterator<typename __table::const_iterator> const_iterator;
+
+    _LIBCPP_INLINE_VISIBILITY
+    hash_multimap() {__table_.rehash(193);}
+    explicit hash_multimap(size_type __n, const hasher& __hf = hasher(),
+                                const key_equal& __eql = key_equal());
+    hash_multimap(size_type __n, const hasher& __hf,
+                                const key_equal& __eql,
+                                const allocator_type& __a);
+    template <class _InputIterator>
+        hash_multimap(_InputIterator __first, _InputIterator __last);
+    template <class _InputIterator>
+        hash_multimap(_InputIterator __first, _InputIterator __last,
+                      size_type __n, const hasher& __hf = hasher(),
+                      const key_equal& __eql = key_equal());
+    template <class _InputIterator>
+        hash_multimap(_InputIterator __first, _InputIterator __last,
+                      size_type __n, const hasher& __hf,
+                      const key_equal& __eql,
+                      const allocator_type& __a);
+    hash_multimap(const hash_multimap& __u);
+
+    _LIBCPP_INLINE_VISIBILITY
+    allocator_type get_allocator() const
+        {return allocator_type(__table_.__node_alloc());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool      empty() const {return __table_.size() == 0;}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type size() const  {return __table_.size();}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type max_size() const {return __table_.max_size();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       begin()        {return __table_.begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       end()          {return __table_.end();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator begin()  const {return __table_.begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator end()    const {return __table_.end();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator insert(const value_type& __x) {return __table_.__insert_multi(__x);}
+    _LIBCPP_INLINE_VISIBILITY
+    iterator insert(const_iterator, const value_type& __x) {return insert(__x);}
+    template <class _InputIterator>
+        void insert(_InputIterator __first, _InputIterator __last);
+
+    _LIBCPP_INLINE_VISIBILITY
+    void erase(const_iterator __p) {__table_.erase(__p.__i_);}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type erase(const key_type& __k) {return __table_.__erase_multi(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    void erase(const_iterator __first, const_iterator __last)
+        {__table_.erase(__first.__i_, __last.__i_);}
+    _LIBCPP_INLINE_VISIBILITY
+    void clear() {__table_.clear();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(hash_multimap& __u) {__table_.swap(__u.__table_);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    hasher hash_funct() const
+        {return __table_.hash_function().hash_function();}
+    _LIBCPP_INLINE_VISIBILITY
+    key_equal key_eq() const
+        {return __table_.key_eq().key_eq();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       find(const key_type& __k)       {return __table_.find(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator find(const key_type& __k) const {return __table_.find(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type count(const key_type& __k) const {return __table_.__count_multi(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    pair<iterator, iterator>             equal_range(const key_type& __k)
+        {return __table_.__equal_range_multi(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
+        {return __table_.__equal_range_multi(__k);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type bucket_count() const {return __table_.bucket_count();}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type max_bucket_count() const {return __table_.max_bucket_count();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type elems_in_bucket(size_type __n) const
+        {return __table_.bucket_size(__n);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void resize(size_type __n) {__table_.rehash(__n);}
+};
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_multimap(
+        size_type __n, const hasher& __hf, const key_equal& __eql)
+    : __table_(__hf, __eql)
+{
+    __table_.rehash(__n);
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_multimap(
+        size_type __n, const hasher& __hf, const key_equal& __eql,
+        const allocator_type& __a)
+    : __table_(__hf, __eql, __a)
+{
+    __table_.rehash(__n);
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+template <class _InputIterator>
+hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_multimap(
+        _InputIterator __first, _InputIterator __last)
+{
+    __table_.rehash(193);
+    insert(__first, __last);
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+template <class _InputIterator>
+hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_multimap(
+        _InputIterator __first, _InputIterator __last, size_type __n,
+        const hasher& __hf, const key_equal& __eql)
+    : __table_(__hf, __eql)
+{
+    __table_.rehash(__n);
+    insert(__first, __last);
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+template <class _InputIterator>
+hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_multimap(
+        _InputIterator __first, _InputIterator __last, size_type __n,
+        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
+    : __table_(__hf, __eql, __a)
+{
+    __table_.rehash(__n);
+    insert(__first, __last);
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_multimap(
+        const hash_multimap& __u)
+    : __table_(__u.__table_)
+{
+    __table_.rehash(__u.bucket_count());
+    insert(__u.begin(), __u.end());
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+template <class _InputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::insert(_InputIterator __first,
+                                                            _InputIterator __last)
+{
+    for (; __first != __last; ++__first)
+        __table_.__insert_multi(*__first);
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
+     hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
+{
+    __x.swap(__y);
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+bool
+operator==(const hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
+           const hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
+{
+    if (__x.size() != __y.size())
+        return false;
+    typedef typename hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::const_iterator
+                                                                 const_iterator;
+    typedef pair<const_iterator, const_iterator> _EqRng;
+    for (const_iterator __i = __x.begin(), __ex = __x.end(); __i != __ex;)
+    {
+        _EqRng __xeq = __x.equal_range(__i->first);
+        _EqRng __yeq = __y.equal_range(__i->first);
+        if (_VSTD::distance(__xeq.first, __xeq.second) !=
+            _VSTD::distance(__yeq.first, __yeq.second) ||
+                  !_VSTD::is_permutation(__xeq.first, __xeq.second, __yeq.first))
+            return false;
+        __i = __xeq.second;
+    }
+    return true;
+}
+
+template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
+           const hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
+{
+    return !(__x == __y);
+}
+
+} // __gnu_cxx
+
+#endif  // _LIBCPP_HASH_MAP

diff --git a/libcxx/include/ext/hash_set b/libcxx/include/ext/hash_set
new file mode 100644
index 0000000..c4bb898
--- /dev/null
+++ b/libcxx/include/ext/hash_set

@@ -0,0 +1,661 @@
+// -*- C++ -*-
+//===------------------------- hash_set ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_HASH_SET
+#define _LIBCPP_HASH_SET
+
+/*
+
+    hash_set synopsis
+
+namespace __gnu_cxx
+{
+
+template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
+          class Alloc = allocator<Value>>
+class hash_set
+{
+public:
+    // types
+    typedef Value                                                      key_type;
+    typedef key_type                                                   value_type;
+    typedef Hash                                                       hasher;
+    typedef Pred                                                       key_equal;
+    typedef Alloc                                                      allocator_type;
+    typedef value_type&                                                reference;
+    typedef const value_type&                                          const_reference;
+    typedef typename allocator_traits<allocator_type>::pointer         pointer;
+    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
+    typedef typename allocator_traits<allocator_type>::size_type       size_type;
+    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
+
+    typedef /unspecified/ iterator;
+    typedef /unspecified/ const_iterator;
+
+    explicit hash_set(size_type n = 193, const hasher& hf = hasher(),
+                           const key_equal& eql = key_equal(),
+                           const allocator_type& a = allocator_type());
+    template <class InputIterator>
+        hash_set(InputIterator f, InputIterator l,
+                      size_type n = 193, const hasher& hf = hasher(),
+                      const key_equal& eql = key_equal(),
+                      const allocator_type& a = allocator_type());
+    hash_set(const hash_set&);
+    ~hash_set();
+    hash_set& operator=(const hash_set&);
+
+    allocator_type get_allocator() const;
+
+    bool      empty() const;
+    size_type size() const;
+    size_type max_size() const;
+
+    iterator       begin();
+    iterator       end();
+    const_iterator begin()  const;
+    const_iterator end()    const;
+
+    pair<iterator, bool> insert(const value_type& obj);
+    template <class InputIterator>
+        void insert(InputIterator first, InputIterator last);
+
+    void erase(const_iterator position);
+    size_type erase(const key_type& k);
+    void erase(const_iterator first, const_iterator last);
+    void clear();
+
+    void swap(hash_set&);
+
+    hasher hash_funct() const;
+    key_equal key_eq() const;
+
+    iterator       find(const key_type& k);
+    const_iterator find(const key_type& k) const;
+    size_type count(const key_type& k) const;
+    pair<iterator, iterator>             equal_range(const key_type& k);
+    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
+
+    size_type bucket_count() const;
+    size_type max_bucket_count() const;
+
+    size_type elems_in_bucket(size_type n) const;
+
+    void resize(size_type n);
+};
+
+template <class Value, class Hash, class Pred, class Alloc>
+    void swap(hash_set<Value, Hash, Pred, Alloc>& x,
+              hash_set<Value, Hash, Pred, Alloc>& y);
+
+template <class Value, class Hash, class Pred, class Alloc>
+    bool
+    operator==(const hash_set<Value, Hash, Pred, Alloc>& x,
+               const hash_set<Value, Hash, Pred, Alloc>& y);
+
+template <class Value, class Hash, class Pred, class Alloc>
+    bool
+    operator!=(const hash_set<Value, Hash, Pred, Alloc>& x,
+               const hash_set<Value, Hash, Pred, Alloc>& y);
+
+template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
+          class Alloc = allocator<Value>>
+class hash_multiset
+{
+public:
+    // types
+    typedef Value                                                      key_type;
+    typedef key_type                                                   value_type;
+    typedef Hash                                                       hasher;
+    typedef Pred                                                       key_equal;
+    typedef Alloc                                                      allocator_type;
+    typedef value_type&                                                reference;
+    typedef const value_type&                                          const_reference;
+    typedef typename allocator_traits<allocator_type>::pointer         pointer;
+    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
+    typedef typename allocator_traits<allocator_type>::size_type       size_type;
+    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
+
+    typedef /unspecified/ iterator;
+    typedef /unspecified/ const_iterator;
+
+    explicit hash_multiset(size_type n = 193, const hasher& hf = hasher(),
+                           const key_equal& eql = key_equal(),
+                           const allocator_type& a = allocator_type());
+    template <class InputIterator>
+        hash_multiset(InputIterator f, InputIterator l,
+                      size_type n = 193, const hasher& hf = hasher(),
+                      const key_equal& eql = key_equal(),
+                      const allocator_type& a = allocator_type());
+    hash_multiset(const hash_multiset&);
+    ~hash_multiset();
+    hash_multiset& operator=(const hash_multiset&);
+
+    allocator_type get_allocator() const;
+
+    bool      empty() const;
+    size_type size() const;
+    size_type max_size() const;
+
+    iterator       begin();
+    iterator       end();
+    const_iterator begin()  const;
+    const_iterator end()    const;
+
+    iterator insert(const value_type& obj);
+    template <class InputIterator>
+        void insert(InputIterator first, InputIterator last);
+
+    void erase(const_iterator position);
+    size_type erase(const key_type& k);
+    void erase(const_iterator first, const_iterator last);
+    void clear();
+
+    void swap(hash_multiset&);
+
+    hasher hash_funct() const;
+    key_equal key_eq() const;
+
+    iterator       find(const key_type& k);
+    const_iterator find(const key_type& k) const;
+    size_type count(const key_type& k) const;
+    pair<iterator, iterator>             equal_range(const key_type& k);
+    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
+
+    size_type bucket_count() const;
+    size_type max_bucket_count() const;
+
+    size_type elems_in_bucket(size_type n) const;
+
+    void resize(size_type n);
+};
+
+template <class Value, class Hash, class Pred, class Alloc>
+    void swap(hash_multiset<Value, Hash, Pred, Alloc>& x,
+              hash_multiset<Value, Hash, Pred, Alloc>& y);
+
+template <class Value, class Hash, class Pred, class Alloc>
+    bool
+    operator==(const hash_multiset<Value, Hash, Pred, Alloc>& x,
+               const hash_multiset<Value, Hash, Pred, Alloc>& y);
+
+template <class Value, class Hash, class Pred, class Alloc>
+    bool
+    operator!=(const hash_multiset<Value, Hash, Pred, Alloc>& x,
+               const hash_multiset<Value, Hash, Pred, Alloc>& y);
+}  // __gnu_cxx
+
+*/
+
+#include <__config>
+#include <__hash_table>
+#include <functional>
+#include <ext/__hash>
+
+#if __DEPRECATED
+#if defined(_MSC_VER) && ! defined(__clang__)
+    _LIBCPP_WARNING("Use of the header <ext/hash_set> is deprecated.  Migrate to <unordered_set>")
+#else
+#   warning Use of the header <ext/hash_set> is deprecated.  Migrate to <unordered_set>
+#endif
+#endif
+
+namespace __gnu_cxx {
+
+using namespace std;
+
+template <class _Value, class _Hash = hash<_Value>, class _Pred = equal_to<_Value>,
+          class _Alloc = allocator<_Value> >
+class _LIBCPP_TYPE_VIS_ONLY hash_set
+{
+public:
+    // types
+    typedef _Value                                                     key_type;
+    typedef key_type                                                   value_type;
+    typedef _Hash                                                      hasher;
+    typedef _Pred                                                      key_equal;
+    typedef _Alloc                                                     allocator_type;
+    typedef value_type&                                                reference;
+    typedef const value_type&                                          const_reference;
+
+private:
+    typedef __hash_table<value_type, hasher, key_equal, allocator_type> __table;
+
+    __table __table_;
+
+public:
+    typedef typename __table::pointer         pointer;
+    typedef typename __table::const_pointer   const_pointer;
+    typedef typename __table::size_type       size_type;
+    typedef typename __table::difference_type difference_type;
+
+    typedef typename __table::const_iterator       iterator;
+    typedef typename __table::const_iterator       const_iterator;
+
+    _LIBCPP_INLINE_VISIBILITY
+    hash_set() {__table_.rehash(193);}
+    explicit hash_set(size_type __n, const hasher& __hf = hasher(),
+                           const key_equal& __eql = key_equal());
+    hash_set(size_type __n, const hasher& __hf, const key_equal& __eql,
+                  const allocator_type& __a);
+    template <class _InputIterator>
+        hash_set(_InputIterator __first, _InputIterator __last);
+    template <class _InputIterator>
+        hash_set(_InputIterator __first, _InputIterator __last,
+                      size_type __n, const hasher& __hf = hasher(),
+                      const key_equal& __eql = key_equal());
+    template <class _InputIterator>
+        hash_set(_InputIterator __first, _InputIterator __last,
+                      size_type __n, const hasher& __hf, const key_equal& __eql,
+                      const allocator_type& __a);
+    hash_set(const hash_set& __u);
+
+    _LIBCPP_INLINE_VISIBILITY
+    allocator_type get_allocator() const
+        {return allocator_type(__table_.__node_alloc());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool      empty() const {return __table_.size() == 0;}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type size() const  {return __table_.size();}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type max_size() const {return __table_.max_size();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       begin()        {return __table_.begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       end()          {return __table_.end();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator begin()  const {return __table_.begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator end()    const {return __table_.end();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    pair<iterator, bool> insert(const value_type& __x)
+        {return __table_.__insert_unique(__x);}
+    _LIBCPP_INLINE_VISIBILITY
+    iterator insert(const_iterator, const value_type& __x) {return insert(__x).first;}
+    template <class _InputIterator>
+        void insert(_InputIterator __first, _InputIterator __last);
+
+    _LIBCPP_INLINE_VISIBILITY
+    void erase(const_iterator __p) {__table_.erase(__p);}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type erase(const key_type& __k) {return __table_.__erase_unique(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    void erase(const_iterator __first, const_iterator __last)
+        {__table_.erase(__first, __last);}
+    _LIBCPP_INLINE_VISIBILITY
+    void clear() {__table_.clear();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(hash_set& __u) {__table_.swap(__u.__table_);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    hasher hash_funct() const {return __table_.hash_function();}
+    _LIBCPP_INLINE_VISIBILITY
+    key_equal key_eq() const {return __table_.key_eq();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       find(const key_type& __k)       {return __table_.find(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator find(const key_type& __k) const {return __table_.find(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type count(const key_type& __k) const {return __table_.__count_unique(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    pair<iterator, iterator>             equal_range(const key_type& __k)
+        {return __table_.__equal_range_unique(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
+        {return __table_.__equal_range_unique(__k);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type bucket_count() const {return __table_.bucket_count();}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type max_bucket_count() const {return __table_.max_bucket_count();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type elems_in_bucket(size_type __n) const {return __table_.bucket_size(__n);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void resize(size_type __n) {__table_.rehash(__n);}
+};
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(size_type __n,
+        const hasher& __hf, const key_equal& __eql)
+    : __table_(__hf, __eql)
+{
+    __table_.rehash(__n);
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(size_type __n,
+        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
+    : __table_(__hf, __eql, __a)
+{
+    __table_.rehash(__n);
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+template <class _InputIterator>
+hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(
+        _InputIterator __first, _InputIterator __last)
+{
+    __table_.rehash(193);
+    insert(__first, __last);
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+template <class _InputIterator>
+hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(
+        _InputIterator __first, _InputIterator __last, size_type __n,
+        const hasher& __hf, const key_equal& __eql)
+    : __table_(__hf, __eql)
+{
+    __table_.rehash(__n);
+    insert(__first, __last);
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+template <class _InputIterator>
+hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(
+        _InputIterator __first, _InputIterator __last, size_type __n,
+        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
+    : __table_(__hf, __eql, __a)
+{
+    __table_.rehash(__n);
+    insert(__first, __last);
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(
+        const hash_set& __u)
+    : __table_(__u.__table_)
+{
+    __table_.rehash(__u.bucket_count());
+    insert(__u.begin(), __u.end());
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+template <class _InputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+hash_set<_Value, _Hash, _Pred, _Alloc>::insert(_InputIterator __first,
+                                                    _InputIterator __last)
+{
+    for (; __first != __last; ++__first)
+        __table_.__insert_unique(*__first);
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(hash_set<_Value, _Hash, _Pred, _Alloc>& __x,
+     hash_set<_Value, _Hash, _Pred, _Alloc>& __y)
+{
+    __x.swap(__y);
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+bool
+operator==(const hash_set<_Value, _Hash, _Pred, _Alloc>& __x,
+           const hash_set<_Value, _Hash, _Pred, _Alloc>& __y)
+{
+    if (__x.size() != __y.size())
+        return false;
+    typedef typename hash_set<_Value, _Hash, _Pred, _Alloc>::const_iterator
+                                                                 const_iterator;
+    for (const_iterator __i = __x.begin(), __ex = __x.end(), __ey = __y.end();
+            __i != __ex; ++__i)
+    {
+        const_iterator __j = __y.find(*__i);
+        if (__j == __ey || !(*__i == *__j))
+            return false;
+    }
+    return true;
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const hash_set<_Value, _Hash, _Pred, _Alloc>& __x,
+           const hash_set<_Value, _Hash, _Pred, _Alloc>& __y)
+{
+    return !(__x == __y);
+}
+
+template <class _Value, class _Hash = hash<_Value>, class _Pred = equal_to<_Value>,
+          class _Alloc = allocator<_Value> >
+class _LIBCPP_TYPE_VIS_ONLY hash_multiset
+{
+public:
+    // types
+    typedef _Value                                                     key_type;
+    typedef key_type                                                   value_type;
+    typedef _Hash                                                      hasher;
+    typedef _Pred                                                      key_equal;
+    typedef _Alloc                                                     allocator_type;
+    typedef value_type&                                                reference;
+    typedef const value_type&                                          const_reference;
+
+private:
+    typedef __hash_table<value_type, hasher, key_equal, allocator_type> __table;
+
+    __table __table_;
+
+public:
+    typedef typename __table::pointer         pointer;
+    typedef typename __table::const_pointer   const_pointer;
+    typedef typename __table::size_type       size_type;
+    typedef typename __table::difference_type difference_type;
+
+    typedef typename __table::const_iterator       iterator;
+    typedef typename __table::const_iterator       const_iterator;
+
+    _LIBCPP_INLINE_VISIBILITY
+    hash_multiset() {__table_.rehash(193);}
+    explicit hash_multiset(size_type __n, const hasher& __hf = hasher(),
+                                const key_equal& __eql = key_equal());
+    hash_multiset(size_type __n, const hasher& __hf,
+                       const key_equal& __eql, const allocator_type& __a);
+    template <class _InputIterator>
+        hash_multiset(_InputIterator __first, _InputIterator __last);
+    template <class _InputIterator>
+        hash_multiset(_InputIterator __first, _InputIterator __last,
+                      size_type __n, const hasher& __hf = hasher(),
+                      const key_equal& __eql = key_equal());
+    template <class _InputIterator>
+        hash_multiset(_InputIterator __first, _InputIterator __last,
+                      size_type __n , const hasher& __hf,
+                      const key_equal& __eql, const allocator_type& __a);
+    hash_multiset(const hash_multiset& __u);
+
+    _LIBCPP_INLINE_VISIBILITY
+    allocator_type get_allocator() const
+        {return allocator_type(__table_.__node_alloc());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool      empty() const {return __table_.size() == 0;}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type size() const  {return __table_.size();}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type max_size() const {return __table_.max_size();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       begin()        {return __table_.begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       end()          {return __table_.end();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator begin()  const {return __table_.begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator end()    const {return __table_.end();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator insert(const value_type& __x) {return __table_.__insert_multi(__x);}
+    _LIBCPP_INLINE_VISIBILITY
+    iterator insert(const_iterator, const value_type& __x) {return insert(__x);}
+    template <class _InputIterator>
+        void insert(_InputIterator __first, _InputIterator __last);
+
+    _LIBCPP_INLINE_VISIBILITY
+    void erase(const_iterator __p) {__table_.erase(__p);}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type erase(const key_type& __k) {return __table_.__erase_multi(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    void erase(const_iterator __first, const_iterator __last)
+        {__table_.erase(__first, __last);}
+    _LIBCPP_INLINE_VISIBILITY
+    void clear() {__table_.clear();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(hash_multiset& __u) {__table_.swap(__u.__table_);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    hasher hash_funct() const {return __table_.hash_function();}
+    _LIBCPP_INLINE_VISIBILITY
+    key_equal key_eq() const {return __table_.key_eq();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       find(const key_type& __k)       {return __table_.find(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator find(const key_type& __k) const {return __table_.find(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type count(const key_type& __k) const {return __table_.__count_multi(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    pair<iterator, iterator>             equal_range(const key_type& __k)
+        {return __table_.__equal_range_multi(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
+        {return __table_.__equal_range_multi(__k);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type bucket_count() const {return __table_.bucket_count();}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type max_bucket_count() const {return __table_.max_bucket_count();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type elems_in_bucket(size_type __n) const {return __table_.bucket_size(__n);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void resize(size_type __n) {__table_.rehash(__n);}
+};
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(
+        size_type __n, const hasher& __hf, const key_equal& __eql)
+    : __table_(__hf, __eql)
+{
+    __table_.rehash(__n);
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(
+        size_type __n, const hasher& __hf, const key_equal& __eql,
+        const allocator_type& __a)
+    : __table_(__hf, __eql, __a)
+{
+    __table_.rehash(__n);
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+template <class _InputIterator>
+hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(
+        _InputIterator __first, _InputIterator __last)
+{
+    __table_.rehash(193);
+    insert(__first, __last);
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+template <class _InputIterator>
+hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(
+        _InputIterator __first, _InputIterator __last, size_type __n,
+        const hasher& __hf, const key_equal& __eql)
+    : __table_(__hf, __eql)
+{
+    __table_.rehash(__n);
+    insert(__first, __last);
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+template <class _InputIterator>
+hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(
+        _InputIterator __first, _InputIterator __last, size_type __n,
+        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
+    : __table_(__hf, __eql, __a)
+{
+    __table_.rehash(__n);
+    insert(__first, __last);
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(
+        const hash_multiset& __u)
+    : __table_(__u.__table_)
+{
+    __table_.rehash(__u.bucket_count());
+    insert(__u.begin(), __u.end());
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+template <class _InputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+hash_multiset<_Value, _Hash, _Pred, _Alloc>::insert(_InputIterator __first,
+                                                         _InputIterator __last)
+{
+    for (; __first != __last; ++__first)
+        __table_.__insert_multi(*__first);
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(hash_multiset<_Value, _Hash, _Pred, _Alloc>& __x,
+     hash_multiset<_Value, _Hash, _Pred, _Alloc>& __y)
+{
+    __x.swap(__y);
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+bool
+operator==(const hash_multiset<_Value, _Hash, _Pred, _Alloc>& __x,
+           const hash_multiset<_Value, _Hash, _Pred, _Alloc>& __y)
+{
+    if (__x.size() != __y.size())
+        return false;
+    typedef typename hash_multiset<_Value, _Hash, _Pred, _Alloc>::const_iterator
+                                                                 const_iterator;
+    typedef pair<const_iterator, const_iterator> _EqRng;
+    for (const_iterator __i = __x.begin(), __ex = __x.end(); __i != __ex;)
+    {
+        _EqRng __xeq = __x.equal_range(*__i);
+        _EqRng __yeq = __y.equal_range(*__i);
+        if (_VSTD::distance(__xeq.first, __xeq.second) !=
+            _VSTD::distance(__yeq.first, __yeq.second) ||
+                  !_VSTD::is_permutation(__xeq.first, __xeq.second, __yeq.first))
+            return false;
+        __i = __xeq.second;
+    }
+    return true;
+}
+
+template <class _Value, class _Hash, class _Pred, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const hash_multiset<_Value, _Hash, _Pred, _Alloc>& __x,
+           const hash_multiset<_Value, _Hash, _Pred, _Alloc>& __y)
+{
+    return !(__x == __y);
+}
+
+} // __gnu_cxx
+
+#endif  // _LIBCPP_HASH_SET

diff --git a/libcxx/include/forward_list b/libcxx/include/forward_list
new file mode 100644
index 0000000..8a87fc5
--- /dev/null
+++ b/libcxx/include/forward_list

@@ -0,0 +1,1649 @@
+// -*- C++ -*-
+//===----------------------- forward_list ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_FORWARD_LIST
+#define _LIBCPP_FORWARD_LIST
+
+/*
+    forward_list synopsis
+
+namespace std
+{
+
+template <class T, class Allocator = allocator<T>>
+class forward_list
+{
+public:
+    typedef T         value_type;
+    typedef Allocator allocator_type;
+
+    typedef value_type&                                                reference;
+    typedef const value_type&                                          const_reference;
+    typedef typename allocator_traits<allocator_type>::pointer         pointer;
+    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
+    typedef typename allocator_traits<allocator_type>::size_type       size_type;
+    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
+
+    typedef <details> iterator;
+    typedef <details> const_iterator;
+
+    forward_list()
+        noexcept(is_nothrow_default_constructible<allocator_type>::value);
+    explicit forward_list(const allocator_type& a);
+    explicit forward_list(size_type n);
+    explicit forward_list(size_type n, const allocator_type& a); // C++14
+    forward_list(size_type n, const value_type& v);
+    forward_list(size_type n, const value_type& v, const allocator_type& a);
+    template <class InputIterator>
+        forward_list(InputIterator first, InputIterator last);
+    template <class InputIterator>
+        forward_list(InputIterator first, InputIterator last, const allocator_type& a);
+    forward_list(const forward_list& x);
+    forward_list(const forward_list& x, const allocator_type& a);
+    forward_list(forward_list&& x)
+        noexcept(is_nothrow_move_constructible<allocator_type>::value);
+    forward_list(forward_list&& x, const allocator_type& a);
+    forward_list(initializer_list<value_type> il);
+    forward_list(initializer_list<value_type> il, const allocator_type& a);
+
+    ~forward_list();
+
+    forward_list& operator=(const forward_list& x);
+    forward_list& operator=(forward_list&& x)
+        noexcept(
+             allocator_type::propagate_on_container_move_assignment::value &&
+             is_nothrow_move_assignable<allocator_type>::value);
+    forward_list& operator=(initializer_list<value_type> il);
+
+    template <class InputIterator>
+        void assign(InputIterator first, InputIterator last);
+    void assign(size_type n, const value_type& v);
+    void assign(initializer_list<value_type> il);
+
+    allocator_type get_allocator() const noexcept;
+
+    iterator       begin() noexcept;
+    const_iterator begin() const noexcept;
+    iterator       end() noexcept;
+    const_iterator end() const noexcept;
+
+    const_iterator cbegin() const noexcept;
+    const_iterator cend() const noexcept;
+
+    iterator       before_begin() noexcept;
+    const_iterator before_begin() const noexcept;
+    const_iterator cbefore_begin() const noexcept;
+
+    bool empty() const noexcept;
+    size_type max_size() const noexcept;
+
+    reference       front();
+    const_reference front() const;
+
+    template <class... Args> void emplace_front(Args&&... args);
+    void push_front(const value_type& v);
+    void push_front(value_type&& v);
+
+    void pop_front();
+
+    template <class... Args>
+        iterator emplace_after(const_iterator p, Args&&... args);
+    iterator insert_after(const_iterator p, const value_type& v);
+    iterator insert_after(const_iterator p, value_type&& v);
+    iterator insert_after(const_iterator p, size_type n, const value_type& v);
+    template <class InputIterator>
+        iterator insert_after(const_iterator p,
+                              InputIterator first, InputIterator last);
+    iterator insert_after(const_iterator p, initializer_list<value_type> il);
+
+    iterator erase_after(const_iterator p);
+    iterator erase_after(const_iterator first, const_iterator last);
+
+    void swap(forward_list& x)
+        noexcept(allocator_traits<allocator_type>::is_always_equal::value);  // C++17
+
+    void resize(size_type n);
+    void resize(size_type n, const value_type& v);
+    void clear() noexcept;
+
+    void splice_after(const_iterator p, forward_list& x);
+    void splice_after(const_iterator p, forward_list&& x);
+    void splice_after(const_iterator p, forward_list& x, const_iterator i);
+    void splice_after(const_iterator p, forward_list&& x, const_iterator i);
+    void splice_after(const_iterator p, forward_list& x,
+                      const_iterator first, const_iterator last);
+    void splice_after(const_iterator p, forward_list&& x,
+                      const_iterator first, const_iterator last);
+    void remove(const value_type& v);
+    template <class Predicate> void remove_if(Predicate pred);
+    void unique();
+    template <class BinaryPredicate> void unique(BinaryPredicate binary_pred);
+    void merge(forward_list& x);
+    void merge(forward_list&& x);
+    template <class Compare> void merge(forward_list& x, Compare comp);
+    template <class Compare> void merge(forward_list&& x, Compare comp);
+    void sort();
+    template <class Compare> void sort(Compare comp);
+    void reverse() noexcept;
+};
+
+template <class T, class Allocator>
+    bool operator==(const forward_list<T, Allocator>& x,
+                    const forward_list<T, Allocator>& y);
+
+template <class T, class Allocator>
+    bool operator< (const forward_list<T, Allocator>& x,
+                    const forward_list<T, Allocator>& y);
+
+template <class T, class Allocator>
+    bool operator!=(const forward_list<T, Allocator>& x,
+                    const forward_list<T, Allocator>& y);
+
+template <class T, class Allocator>
+    bool operator> (const forward_list<T, Allocator>& x,
+                    const forward_list<T, Allocator>& y);
+
+template <class T, class Allocator>
+    bool operator>=(const forward_list<T, Allocator>& x,
+                    const forward_list<T, Allocator>& y);
+
+template <class T, class Allocator>
+    bool operator<=(const forward_list<T, Allocator>& x,
+                    const forward_list<T, Allocator>& y);
+
+template <class T, class Allocator>
+    void swap(forward_list<T, Allocator>& x, forward_list<T, Allocator>& y)
+         noexcept(noexcept(x.swap(y)));
+
+}  // std
+
+*/
+
+#include <__config>
+
+#include <initializer_list>
+#include <memory>
+#include <limits>
+#include <iterator>
+#include <algorithm>
+
+#include <__undef_min_max>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp, class _VoidPtr> struct __forward_list_node;
+
+template <class _NodePtr>
+struct __forward_begin_node
+{
+    typedef _NodePtr pointer;
+
+    pointer __next_;
+
+     _LIBCPP_INLINE_VISIBILITY __forward_begin_node() : __next_(nullptr) {}
+};
+
+template <class _Tp, class _VoidPtr>
+struct _LIBCPP_HIDDEN __begin_node_of
+{
+    typedef __forward_begin_node
+        <
+             typename pointer_traits<_VoidPtr>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+                 rebind<__forward_list_node<_Tp, _VoidPtr> >
+#else
+                 rebind<__forward_list_node<_Tp, _VoidPtr> >::other
+#endif
+         > type;
+};
+
+template <class _Tp, class _VoidPtr>
+struct __forward_list_node
+    : public __begin_node_of<_Tp, _VoidPtr>::type
+{
+    typedef _Tp value_type;
+
+    value_type __value_;
+};
+
+template <class _Tp, class _Alloc = allocator<_Tp> > class _LIBCPP_TYPE_VIS_ONLY forward_list;
+template<class _NodeConstPtr> class _LIBCPP_TYPE_VIS_ONLY __forward_list_const_iterator;
+
+template <class _NodePtr>
+class _LIBCPP_TYPE_VIS_ONLY __forward_list_iterator
+{
+    typedef _NodePtr __node_pointer;
+
+    __node_pointer __ptr_;
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __forward_list_iterator(__node_pointer __p) _NOEXCEPT : __ptr_(__p) {}
+
+    template<class, class> friend class _LIBCPP_TYPE_VIS_ONLY forward_list;
+    template<class> friend class _LIBCPP_TYPE_VIS_ONLY __forward_list_const_iterator;
+
+public:
+    typedef forward_iterator_tag                              iterator_category;
+    typedef typename pointer_traits<__node_pointer>::element_type::value_type
+                                                              value_type;
+    typedef value_type&                                       reference;
+    typedef typename pointer_traits<__node_pointer>::difference_type
+                                                              difference_type;
+    typedef typename pointer_traits<__node_pointer>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<value_type>
+#else
+            rebind<value_type>::other
+#endif
+                                                              pointer;
+
+    _LIBCPP_INLINE_VISIBILITY
+    __forward_list_iterator() _NOEXCEPT : __ptr_(nullptr) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    reference operator*() const {return __ptr_->__value_;}
+    _LIBCPP_INLINE_VISIBILITY
+    pointer operator->() const {return pointer_traits<pointer>::pointer_to(__ptr_->__value_);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __forward_list_iterator& operator++()
+    {
+        __ptr_ = __ptr_->__next_;
+        return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    __forward_list_iterator operator++(int)
+    {
+        __forward_list_iterator __t(*this);
+        ++(*this);
+        return __t;
+    }
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator==(const __forward_list_iterator& __x,
+                    const __forward_list_iterator& __y)
+        {return __x.__ptr_ == __y.__ptr_;}
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(const __forward_list_iterator& __x,
+                    const __forward_list_iterator& __y)
+        {return !(__x == __y);}
+};
+
+template <class _NodeConstPtr>
+class _LIBCPP_TYPE_VIS_ONLY __forward_list_const_iterator
+{
+    typedef _NodeConstPtr __node_const_pointer;
+
+    __node_const_pointer __ptr_;
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __forward_list_const_iterator(__node_const_pointer __p) _NOEXCEPT
+        : __ptr_(__p) {}
+
+    typedef typename remove_const
+        <
+            typename pointer_traits<__node_const_pointer>::element_type
+        >::type                                               __node;
+    typedef typename pointer_traits<__node_const_pointer>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<__node>
+#else
+            rebind<__node>::other
+#endif
+                                                              __node_pointer;
+
+    template<class, class> friend class forward_list;
+
+public:
+    typedef forward_iterator_tag                              iterator_category;
+    typedef typename __node::value_type                       value_type;
+    typedef const value_type&                                 reference;
+    typedef typename pointer_traits<__node_const_pointer>::difference_type
+                                                              difference_type;
+    typedef typename pointer_traits<__node_const_pointer>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<const value_type>
+#else
+            rebind<const value_type>::other
+#endif
+                                                              pointer;
+
+    _LIBCPP_INLINE_VISIBILITY
+    __forward_list_const_iterator() _NOEXCEPT : __ptr_(nullptr) {}
+    _LIBCPP_INLINE_VISIBILITY
+    __forward_list_const_iterator(__forward_list_iterator<__node_pointer> __p) _NOEXCEPT
+        : __ptr_(__p.__ptr_) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    reference operator*() const {return __ptr_->__value_;}
+    _LIBCPP_INLINE_VISIBILITY
+    pointer operator->() const {return pointer_traits<pointer>::pointer_to(__ptr_->__value_);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __forward_list_const_iterator& operator++()
+    {
+        __ptr_ = __ptr_->__next_;
+        return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    __forward_list_const_iterator operator++(int)
+    {
+        __forward_list_const_iterator __t(*this);
+        ++(*this);
+        return __t;
+    }
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator==(const __forward_list_const_iterator& __x,
+                    const __forward_list_const_iterator& __y)
+        {return __x.__ptr_ == __y.__ptr_;}
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(const __forward_list_const_iterator& __x,
+                           const __forward_list_const_iterator& __y)
+        {return !(__x == __y);}
+};
+
+template <class _Tp, class _Alloc>
+class __forward_list_base
+{
+protected:
+    typedef _Tp    value_type;
+    typedef _Alloc allocator_type;
+
+    typedef typename allocator_traits<allocator_type>::void_pointer  void_pointer;
+    typedef __forward_list_node<value_type, void_pointer>            __node;
+    typedef typename __begin_node_of<value_type, void_pointer>::type __begin_node;
+    typedef typename __rebind_alloc_helper<allocator_traits<allocator_type>, __node>::type __node_allocator;
+    typedef allocator_traits<__node_allocator>        __node_traits;
+    typedef typename __node_traits::pointer           __node_pointer;
+    typedef typename __node_traits::pointer           __node_const_pointer;
+
+    typedef typename __rebind_alloc_helper<allocator_traits<allocator_type>, __begin_node>::type __begin_node_allocator;
+    typedef typename allocator_traits<__begin_node_allocator>::pointer __begin_node_pointer;
+
+    __compressed_pair<__begin_node, __node_allocator> __before_begin_;
+
+    _LIBCPP_INLINE_VISIBILITY
+    __node_pointer        __before_begin() _NOEXCEPT
+        {return static_cast<__node_pointer>(pointer_traits<__begin_node_pointer>::
+                                        pointer_to(__before_begin_.first()));}
+    _LIBCPP_INLINE_VISIBILITY
+    __node_const_pointer  __before_begin() const _NOEXCEPT
+        {return static_cast<__node_const_pointer>(pointer_traits<__begin_node_pointer>::
+                                        pointer_to(const_cast<__begin_node&>(__before_begin_.first())));}
+
+    _LIBCPP_INLINE_VISIBILITY
+          __node_allocator& __alloc() _NOEXCEPT
+            {return __before_begin_.second();}
+    _LIBCPP_INLINE_VISIBILITY
+    const __node_allocator& __alloc() const _NOEXCEPT
+        {return __before_begin_.second();}
+
+    typedef __forward_list_iterator<__node_pointer>             iterator;
+    typedef __forward_list_const_iterator<__node_pointer>       const_iterator;
+
+    _LIBCPP_INLINE_VISIBILITY
+    __forward_list_base()
+        _NOEXCEPT_(is_nothrow_default_constructible<__node_allocator>::value)
+        : __before_begin_(__begin_node()) {}
+    _LIBCPP_INLINE_VISIBILITY
+    __forward_list_base(const allocator_type& __a)
+        : __before_begin_(__begin_node(), __node_allocator(__a)) {}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+public:
+    __forward_list_base(__forward_list_base&& __x)
+        _NOEXCEPT_(is_nothrow_move_constructible<__node_allocator>::value);
+    __forward_list_base(__forward_list_base&& __x, const allocator_type& __a);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+private:
+    __forward_list_base(const __forward_list_base&);
+    __forward_list_base& operator=(const __forward_list_base&);
+
+public:
+    ~__forward_list_base();
+
+protected:
+    _LIBCPP_INLINE_VISIBILITY
+    void __copy_assign_alloc(const __forward_list_base& __x)
+        {__copy_assign_alloc(__x, integral_constant<bool,
+              __node_traits::propagate_on_container_copy_assignment::value>());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__forward_list_base& __x)
+        _NOEXCEPT_(!__node_traits::propagate_on_container_move_assignment::value ||
+                   is_nothrow_move_assignable<__node_allocator>::value)
+        {__move_assign_alloc(__x, integral_constant<bool,
+              __node_traits::propagate_on_container_move_assignment::value>());}
+
+public:
+    void swap(__forward_list_base& __x)
+#if _LIBCPP_STD_VER >= 14
+        _NOEXCEPT;
+#else
+        _NOEXCEPT_(!__node_traits::propagate_on_container_move_assignment::value || 
+                    __is_nothrow_swappable<__node_allocator>::value);
+#endif
+protected:
+    void clear() _NOEXCEPT;
+
+private:
+    _LIBCPP_INLINE_VISIBILITY
+    void __copy_assign_alloc(const __forward_list_base&, false_type) {}
+    _LIBCPP_INLINE_VISIBILITY
+    void __copy_assign_alloc(const __forward_list_base& __x, true_type)
+    {
+        if (__alloc() != __x.__alloc())
+            clear();
+        __alloc() = __x.__alloc();
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__forward_list_base& __x, false_type) _NOEXCEPT
+        {}
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__forward_list_base& __x, true_type)
+        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value)
+        {__alloc() = _VSTD::move(__x.__alloc());}
+};
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+__forward_list_base<_Tp, _Alloc>::__forward_list_base(__forward_list_base&& __x)
+        _NOEXCEPT_(is_nothrow_move_constructible<__node_allocator>::value)
+    : __before_begin_(_VSTD::move(__x.__before_begin_))
+{
+    __x.__before_begin()->__next_ = nullptr;
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+__forward_list_base<_Tp, _Alloc>::__forward_list_base(__forward_list_base&& __x,
+                                                      const allocator_type& __a)
+    : __before_begin_(__begin_node(), __node_allocator(__a))
+{
+    if (__alloc() == __x.__alloc())
+    {
+        __before_begin()->__next_ = __x.__before_begin()->__next_;
+        __x.__before_begin()->__next_ = nullptr;
+    }
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Alloc>
+__forward_list_base<_Tp, _Alloc>::~__forward_list_base()
+{
+    clear();
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__forward_list_base<_Tp, _Alloc>::swap(__forward_list_base& __x)
+#if _LIBCPP_STD_VER >= 14
+        _NOEXCEPT
+#else
+        _NOEXCEPT_(!__node_traits::propagate_on_container_move_assignment::value || 
+                    __is_nothrow_swappable<__node_allocator>::value)
+#endif
+{
+    __swap_allocator(__alloc(), __x.__alloc(), 
+            integral_constant<bool, __node_traits::propagate_on_container_swap::value>());
+    using _VSTD::swap;
+    swap(__before_begin()->__next_, __x.__before_begin()->__next_);
+}
+
+template <class _Tp, class _Alloc>
+void
+__forward_list_base<_Tp, _Alloc>::clear() _NOEXCEPT
+{
+    __node_allocator& __a = __alloc();
+    for (__node_pointer __p = __before_begin()->__next_; __p != nullptr;)
+    {
+        __node_pointer __next = __p->__next_;
+        __node_traits::destroy(__a, _VSTD::addressof(__p->__value_));
+        __node_traits::deallocate(__a, __p, 1);
+        __p = __next;
+    }
+    __before_begin()->__next_ = nullptr;
+}
+
+template <class _Tp, class _Alloc /*= allocator<_Tp>*/>
+class _LIBCPP_TYPE_VIS_ONLY forward_list
+    : private __forward_list_base<_Tp, _Alloc>
+{
+    typedef __forward_list_base<_Tp, _Alloc> base;
+    typedef typename base::__node_allocator  __node_allocator;
+    typedef typename base::__node            __node;
+    typedef typename base::__node_traits     __node_traits;
+    typedef typename base::__node_pointer    __node_pointer;
+
+public:
+    typedef _Tp    value_type;
+    typedef _Alloc allocator_type;
+
+    typedef value_type&                                                reference;
+    typedef const value_type&                                          const_reference;
+    typedef typename allocator_traits<allocator_type>::pointer         pointer;
+    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
+    typedef typename allocator_traits<allocator_type>::size_type       size_type;
+    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
+
+    typedef typename base::iterator       iterator;
+    typedef typename base::const_iterator const_iterator;
+
+    _LIBCPP_INLINE_VISIBILITY
+    forward_list()
+        _NOEXCEPT_(is_nothrow_default_constructible<__node_allocator>::value)
+        {} // = default;
+    explicit forward_list(const allocator_type& __a);
+    explicit forward_list(size_type __n);
+#if _LIBCPP_STD_VER > 11
+    explicit forward_list(size_type __n, const allocator_type& __a);
+#endif
+    forward_list(size_type __n, const value_type& __v);
+    forward_list(size_type __n, const value_type& __v, const allocator_type& __a);
+    template <class _InputIterator>
+        forward_list(_InputIterator __f, _InputIterator __l,
+                     typename enable_if<
+                       __is_input_iterator<_InputIterator>::value
+                     >::type* = nullptr);
+    template <class _InputIterator>
+        forward_list(_InputIterator __f, _InputIterator __l,
+                     const allocator_type& __a,
+                     typename enable_if<
+                       __is_input_iterator<_InputIterator>::value
+                     >::type* = nullptr);
+    forward_list(const forward_list& __x);
+    forward_list(const forward_list& __x, const allocator_type& __a);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    forward_list(forward_list&& __x)
+        _NOEXCEPT_(is_nothrow_move_constructible<base>::value)
+        : base(_VSTD::move(__x)) {}
+    forward_list(forward_list&& __x, const allocator_type& __a);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+    forward_list(initializer_list<value_type> __il);
+    forward_list(initializer_list<value_type> __il, const allocator_type& __a);
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+    // ~forward_list() = default;
+
+    forward_list& operator=(const forward_list& __x);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    forward_list& operator=(forward_list&& __x)
+        _NOEXCEPT_(
+             __node_traits::propagate_on_container_move_assignment::value &&
+             is_nothrow_move_assignable<allocator_type>::value);
+#endif
+#ifndef  _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+    forward_list& operator=(initializer_list<value_type> __il);
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+    template <class _InputIterator>
+        typename enable_if
+        <
+            __is_input_iterator<_InputIterator>::value,
+            void
+        >::type
+        assign(_InputIterator __f, _InputIterator __l);
+    void assign(size_type __n, const value_type& __v);
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+    void assign(initializer_list<value_type> __il);
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+    _LIBCPP_INLINE_VISIBILITY
+    allocator_type get_allocator() const _NOEXCEPT
+        {return allocator_type(base::__alloc());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       begin() _NOEXCEPT
+        {return       iterator(base::__before_begin()->__next_);}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator begin() const _NOEXCEPT
+        {return const_iterator(base::__before_begin()->__next_);}
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       end() _NOEXCEPT
+        {return       iterator(nullptr);}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator end() const _NOEXCEPT
+        {return const_iterator(nullptr);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator cbegin() const _NOEXCEPT
+        {return const_iterator(base::__before_begin()->__next_);}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator cend() const _NOEXCEPT
+        {return const_iterator(nullptr);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator       before_begin() _NOEXCEPT
+        {return       iterator(base::__before_begin());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator before_begin() const _NOEXCEPT
+        {return const_iterator(base::__before_begin());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator cbefore_begin() const _NOEXCEPT
+        {return const_iterator(base::__before_begin());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool empty() const _NOEXCEPT
+        {return base::__before_begin()->__next_ == nullptr;}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type max_size() const _NOEXCEPT
+        {return numeric_limits<size_type>::max();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    reference       front()       {return base::__before_begin()->__next_->__value_;}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reference front() const {return base::__before_begin()->__next_->__value_;}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    template <class... _Args> void emplace_front(_Args&&... __args);
+#endif
+    void push_front(value_type&& __v);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    void push_front(const value_type& __v);
+
+    void pop_front();
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    template <class... _Args>
+        iterator emplace_after(const_iterator __p, _Args&&... __args);
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+    iterator insert_after(const_iterator __p, value_type&& __v);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    iterator insert_after(const_iterator __p, const value_type& __v);
+    iterator insert_after(const_iterator __p, size_type __n, const value_type& __v);
+    template <class _InputIterator>
+        _LIBCPP_INLINE_VISIBILITY
+        typename enable_if
+        <
+            __is_input_iterator<_InputIterator>::value,
+            iterator
+        >::type
+        insert_after(const_iterator __p, _InputIterator __f, _InputIterator __l);
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+    iterator insert_after(const_iterator __p, initializer_list<value_type> __il)
+        {return insert_after(__p, __il.begin(), __il.end());}
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+    iterator erase_after(const_iterator __p);
+    iterator erase_after(const_iterator __f, const_iterator __l);
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(forward_list& __x)
+#if _LIBCPP_STD_VER >= 14
+        _NOEXCEPT
+#else
+        _NOEXCEPT_(!__node_traits::propagate_on_container_swap::value ||
+                   __is_nothrow_swappable<__node_allocator>::value)
+#endif
+        {base::swap(__x);}
+
+    void resize(size_type __n);
+    void resize(size_type __n, const value_type& __v);
+    _LIBCPP_INLINE_VISIBILITY
+    void clear() _NOEXCEPT {base::clear();}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    void splice_after(const_iterator __p, forward_list&& __x);
+    _LIBCPP_INLINE_VISIBILITY
+    void splice_after(const_iterator __p, forward_list&& __x, const_iterator __i);
+    _LIBCPP_INLINE_VISIBILITY
+    void splice_after(const_iterator __p, forward_list&& __x,
+                      const_iterator __f, const_iterator __l);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    void splice_after(const_iterator __p, forward_list& __x);
+    void splice_after(const_iterator __p, forward_list& __x, const_iterator __i);
+    void splice_after(const_iterator __p, forward_list& __x,
+                      const_iterator __f, const_iterator __l);
+    void remove(const value_type& __v);
+    template <class _Predicate> void remove_if(_Predicate __pred);
+    _LIBCPP_INLINE_VISIBILITY
+    void unique() {unique(__equal_to<value_type>());}
+    template <class _BinaryPredicate> void unique(_BinaryPredicate __binary_pred);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    void merge(forward_list&& __x) {merge(__x, __less<value_type>());}
+    template <class _Compare>
+        _LIBCPP_INLINE_VISIBILITY
+        void merge(forward_list&& __x, _Compare __comp)
+        {merge(__x, _VSTD::move(__comp));}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    void merge(forward_list& __x) {merge(__x, __less<value_type>());}
+    template <class _Compare> void merge(forward_list& __x, _Compare __comp);
+    _LIBCPP_INLINE_VISIBILITY
+    void sort() {sort(__less<value_type>());}
+    template <class _Compare> void sort(_Compare __comp);
+    void reverse() _NOEXCEPT;
+
+private:
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    void __move_assign(forward_list& __x, true_type)
+        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value);
+    void __move_assign(forward_list& __x, false_type);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    template <class _Compare>
+        static
+        __node_pointer
+        __merge(__node_pointer __f1, __node_pointer __f2, _Compare& __comp);
+
+    template <class _Compare>
+        static
+        __node_pointer
+        __sort(__node_pointer __f, difference_type __sz, _Compare& __comp);
+};
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+forward_list<_Tp, _Alloc>::forward_list(const allocator_type& __a)
+    : base(__a)
+{
+}
+
+template <class _Tp, class _Alloc>
+forward_list<_Tp, _Alloc>::forward_list(size_type __n)
+{
+    if (__n > 0)
+    {
+        __node_allocator& __a = base::__alloc();
+        typedef __allocator_destructor<__node_allocator> _Dp;
+        unique_ptr<__node, _Dp> __h(nullptr, _Dp(__a, 1));
+        for (__node_pointer __p = base::__before_begin(); __n > 0; --__n,
+                                                             __p = __p->__next_)
+        {
+            __h.reset(__node_traits::allocate(__a, 1));
+            __node_traits::construct(__a, _VSTD::addressof(__h->__value_));
+            __h->__next_ = nullptr;
+            __p->__next_ = __h.release();
+        }
+    }
+}
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp, class _Alloc>
+forward_list<_Tp, _Alloc>::forward_list(size_type __n, const allocator_type& __a)
+    : base ( __a )
+{
+    if (__n > 0)
+    {
+        __node_allocator& __a = base::__alloc();
+        typedef __allocator_destructor<__node_allocator> _Dp;
+        unique_ptr<__node, _Dp> __h(nullptr, _Dp(__a, 1));
+        for (__node_pointer __p = base::__before_begin(); __n > 0; --__n,
+                                                             __p = __p->__next_)
+        {
+            __h.reset(__node_traits::allocate(__a, 1));
+            __node_traits::construct(__a, _VSTD::addressof(__h->__value_));
+            __h->__next_ = nullptr;
+            __p->__next_ = __h.release();
+        }
+    }
+}
+#endif
+
+template <class _Tp, class _Alloc>
+forward_list<_Tp, _Alloc>::forward_list(size_type __n, const value_type& __v)
+{
+    insert_after(cbefore_begin(), __n, __v);
+}
+
+template <class _Tp, class _Alloc>
+forward_list<_Tp, _Alloc>::forward_list(size_type __n, const value_type& __v,
+                                        const allocator_type& __a)
+    : base(__a)
+{
+    insert_after(cbefore_begin(), __n, __v);
+}
+
+template <class _Tp, class _Alloc>
+template <class _InputIterator>
+forward_list<_Tp, _Alloc>::forward_list(_InputIterator __f, _InputIterator __l,
+                                        typename enable_if<
+                                          __is_input_iterator<_InputIterator>::value
+                                        >::type*)
+{
+    insert_after(cbefore_begin(), __f, __l);
+}
+
+template <class _Tp, class _Alloc>
+template <class _InputIterator>
+forward_list<_Tp, _Alloc>::forward_list(_InputIterator __f, _InputIterator __l,
+                                        const allocator_type& __a,
+                                        typename enable_if<
+                                          __is_input_iterator<_InputIterator>::value
+                                        >::type*)
+    : base(__a)
+{
+    insert_after(cbefore_begin(), __f, __l);
+}
+
+template <class _Tp, class _Alloc>
+forward_list<_Tp, _Alloc>::forward_list(const forward_list& __x)
+    : base(allocator_type(
+             __node_traits::select_on_container_copy_construction(__x.__alloc())
+                         )
+          )
+{
+    insert_after(cbefore_begin(), __x.begin(), __x.end());
+}
+
+template <class _Tp, class _Alloc>
+forward_list<_Tp, _Alloc>::forward_list(const forward_list& __x,
+                                        const allocator_type& __a)
+    : base(__a)
+{
+    insert_after(cbefore_begin(), __x.begin(), __x.end());
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Alloc>
+forward_list<_Tp, _Alloc>::forward_list(forward_list&& __x,
+                                        const allocator_type& __a)
+    : base(_VSTD::move(__x), __a)
+{
+    if (base::__alloc() != __x.__alloc())
+    {
+        typedef move_iterator<iterator> _Ip;
+        insert_after(cbefore_begin(), _Ip(__x.begin()), _Ip(__x.end()));
+    }
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+template <class _Tp, class _Alloc>
+forward_list<_Tp, _Alloc>::forward_list(initializer_list<value_type> __il)
+{
+    insert_after(cbefore_begin(), __il.begin(), __il.end());
+}
+
+template <class _Tp, class _Alloc>
+forward_list<_Tp, _Alloc>::forward_list(initializer_list<value_type> __il,
+                                        const allocator_type& __a)
+    : base(__a)
+{
+    insert_after(cbefore_begin(), __il.begin(), __il.end());
+}
+
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+template <class _Tp, class _Alloc>
+forward_list<_Tp, _Alloc>&
+forward_list<_Tp, _Alloc>::operator=(const forward_list& __x)
+{
+    if (this != &__x)
+    {
+        base::__copy_assign_alloc(__x);
+        assign(__x.begin(), __x.end());
+    }
+    return *this;
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Alloc>
+void
+forward_list<_Tp, _Alloc>::__move_assign(forward_list& __x, true_type)
+    _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
+{
+    clear();
+    base::__move_assign_alloc(__x);
+    base::__before_begin()->__next_ = __x.__before_begin()->__next_;
+    __x.__before_begin()->__next_ = nullptr;
+}
+
+template <class _Tp, class _Alloc>
+void
+forward_list<_Tp, _Alloc>::__move_assign(forward_list& __x, false_type)
+{
+    if (base::__alloc() == __x.__alloc())
+        __move_assign(__x, true_type());
+    else
+    {
+        typedef move_iterator<iterator> _Ip;
+        assign(_Ip(__x.begin()), _Ip(__x.end()));
+    }
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+forward_list<_Tp, _Alloc>&
+forward_list<_Tp, _Alloc>::operator=(forward_list&& __x)
+    _NOEXCEPT_(
+             __node_traits::propagate_on_container_move_assignment::value &&
+             is_nothrow_move_assignable<allocator_type>::value)
+{
+    __move_assign(__x, integral_constant<bool,
+          __node_traits::propagate_on_container_move_assignment::value>());
+    return *this;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+forward_list<_Tp, _Alloc>&
+forward_list<_Tp, _Alloc>::operator=(initializer_list<value_type> __il)
+{
+    assign(__il.begin(), __il.end());
+    return *this;
+}
+
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+template <class _Tp, class _Alloc>
+template <class _InputIterator>
+typename enable_if
+<
+    __is_input_iterator<_InputIterator>::value,
+    void
+>::type
+forward_list<_Tp, _Alloc>::assign(_InputIterator __f, _InputIterator __l)
+{
+    iterator __i = before_begin();
+    iterator __j = _VSTD::next(__i);
+    iterator __e = end();
+    for (; __j != __e && __f != __l; ++__i, (void) ++__j, ++__f)
+        *__j = *__f;
+    if (__j == __e)
+        insert_after(__i, __f, __l);
+    else
+        erase_after(__i, __e);
+}
+
+template <class _Tp, class _Alloc>
+void
+forward_list<_Tp, _Alloc>::assign(size_type __n, const value_type& __v)
+{
+    iterator __i = before_begin();
+    iterator __j = _VSTD::next(__i);
+    iterator __e = end();
+    for (; __j != __e && __n > 0; --__n, ++__i, ++__j)
+        *__j = __v;
+    if (__j == __e)
+        insert_after(__i, __n, __v);
+    else
+        erase_after(__i, __e);
+}
+
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+forward_list<_Tp, _Alloc>::assign(initializer_list<value_type> __il)
+{
+    assign(__il.begin(), __il.end());
+}
+
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Alloc>
+template <class... _Args>
+void
+forward_list<_Tp, _Alloc>::emplace_front(_Args&&... __args)
+{
+    __node_allocator& __a = base::__alloc();
+    typedef __allocator_destructor<__node_allocator> _Dp;
+    unique_ptr<__node, _Dp> __h(__node_traits::allocate(__a, 1), _Dp(__a, 1));
+    __node_traits::construct(__a, _VSTD::addressof(__h->__value_),
+                                  _VSTD::forward<_Args>(__args)...);
+    __h->__next_ = base::__before_begin()->__next_;
+    base::__before_begin()->__next_ = __h.release();
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Alloc>
+void
+forward_list<_Tp, _Alloc>::push_front(value_type&& __v)
+{
+    __node_allocator& __a = base::__alloc();
+    typedef __allocator_destructor<__node_allocator> _Dp;
+    unique_ptr<__node, _Dp> __h(__node_traits::allocate(__a, 1), _Dp(__a, 1));
+    __node_traits::construct(__a, _VSTD::addressof(__h->__value_), _VSTD::move(__v));
+    __h->__next_ = base::__before_begin()->__next_;
+    base::__before_begin()->__next_ = __h.release();
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Alloc>
+void
+forward_list<_Tp, _Alloc>::push_front(const value_type& __v)
+{
+    __node_allocator& __a = base::__alloc();
+    typedef __allocator_destructor<__node_allocator> _Dp;
+    unique_ptr<__node, _Dp> __h(__node_traits::allocate(__a, 1), _Dp(__a, 1));
+    __node_traits::construct(__a, _VSTD::addressof(__h->__value_), __v);
+    __h->__next_ = base::__before_begin()->__next_;
+    base::__before_begin()->__next_ = __h.release();
+}
+
+template <class _Tp, class _Alloc>
+void
+forward_list<_Tp, _Alloc>::pop_front()
+{
+    __node_allocator& __a = base::__alloc();
+    __node_pointer __p = base::__before_begin()->__next_;
+    base::__before_begin()->__next_ = __p->__next_;
+    __node_traits::destroy(__a, _VSTD::addressof(__p->__value_));
+    __node_traits::deallocate(__a, __p, 1);
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Alloc>
+template <class... _Args>
+typename forward_list<_Tp, _Alloc>::iterator
+forward_list<_Tp, _Alloc>::emplace_after(const_iterator __p, _Args&&... __args)
+{
+    __node_pointer const __r = __p.__ptr_;
+    __node_allocator& __a = base::__alloc();
+    typedef __allocator_destructor<__node_allocator> _Dp;
+    unique_ptr<__node, _Dp> __h(__node_traits::allocate(__a, 1), _Dp(__a, 1));
+    __node_traits::construct(__a, _VSTD::addressof(__h->__value_),
+                                  _VSTD::forward<_Args>(__args)...);
+    __h->__next_ = __r->__next_;
+    __r->__next_ = __h.release();
+    return iterator(__r->__next_);
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Alloc>
+typename forward_list<_Tp, _Alloc>::iterator
+forward_list<_Tp, _Alloc>::insert_after(const_iterator __p, value_type&& __v)
+{
+    __node_pointer const __r = __p.__ptr_;
+    __node_allocator& __a = base::__alloc();
+    typedef __allocator_destructor<__node_allocator> _Dp;
+    unique_ptr<__node, _Dp> __h(__node_traits::allocate(__a, 1), _Dp(__a, 1));
+    __node_traits::construct(__a, _VSTD::addressof(__h->__value_), _VSTD::move(__v));
+    __h->__next_ = __r->__next_;
+    __r->__next_ = __h.release();
+    return iterator(__r->__next_);
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Alloc>
+typename forward_list<_Tp, _Alloc>::iterator
+forward_list<_Tp, _Alloc>::insert_after(const_iterator __p, const value_type& __v)
+{
+    __node_pointer const __r = __p.__ptr_;
+    __node_allocator& __a = base::__alloc();
+    typedef __allocator_destructor<__node_allocator> _Dp;
+    unique_ptr<__node, _Dp> __h(__node_traits::allocate(__a, 1), _Dp(__a, 1));
+    __node_traits::construct(__a, _VSTD::addressof(__h->__value_), __v);
+    __h->__next_ = __r->__next_;
+    __r->__next_ = __h.release();
+    return iterator(__r->__next_);
+}
+
+template <class _Tp, class _Alloc>
+typename forward_list<_Tp, _Alloc>::iterator
+forward_list<_Tp, _Alloc>::insert_after(const_iterator __p, size_type __n,
+                                        const value_type& __v)
+{
+    __node_pointer __r = __p.__ptr_;
+    if (__n > 0)
+    {
+        __node_allocator& __a = base::__alloc();
+        typedef __allocator_destructor<__node_allocator> _Dp;
+        unique_ptr<__node, _Dp> __h(__node_traits::allocate(__a, 1), _Dp(__a, 1));
+        __node_traits::construct(__a, _VSTD::addressof(__h->__value_), __v);
+        __node_pointer __first = __h.release();
+        __node_pointer __last = __first;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        try
+        {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            for (--__n; __n != 0; --__n, __last = __last->__next_)
+            {
+                __h.reset(__node_traits::allocate(__a, 1));
+                __node_traits::construct(__a, _VSTD::addressof(__h->__value_), __v);
+                __last->__next_ = __h.release();
+            }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        }
+        catch (...)
+        {
+            while (__first != nullptr)
+            {
+                __node_pointer __next = __first->__next_;
+                __node_traits::destroy(__a, _VSTD::addressof(__first->__value_));
+                __node_traits::deallocate(__a, __first, 1);
+                __first = __next;
+            }
+            throw;
+        }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        __last->__next_ = __r->__next_;
+        __r->__next_ = __first;
+        __r = __last;
+    }
+    return iterator(__r);
+}
+
+template <class _Tp, class _Alloc>
+template <class _InputIterator>
+typename enable_if
+<
+    __is_input_iterator<_InputIterator>::value,
+    typename forward_list<_Tp, _Alloc>::iterator
+>::type
+forward_list<_Tp, _Alloc>::insert_after(const_iterator __p,
+                                        _InputIterator __f, _InputIterator __l)
+{
+    __node_pointer __r = __p.__ptr_;
+    if (__f != __l)
+    {
+        __node_allocator& __a = base::__alloc();
+        typedef __allocator_destructor<__node_allocator> _Dp;
+        unique_ptr<__node, _Dp> __h(__node_traits::allocate(__a, 1), _Dp(__a, 1));
+        __node_traits::construct(__a, _VSTD::addressof(__h->__value_), *__f);
+        __node_pointer __first = __h.release();
+        __node_pointer __last = __first;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        try
+        {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            for (++__f; __f != __l; ++__f, ((void)(__last = __last->__next_)))
+            {
+                __h.reset(__node_traits::allocate(__a, 1));
+                __node_traits::construct(__a, _VSTD::addressof(__h->__value_), *__f);
+                __last->__next_ = __h.release();
+            }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        }
+        catch (...)
+        {
+            while (__first != nullptr)
+            {
+                __node_pointer __next = __first->__next_;
+                __node_traits::destroy(__a, _VSTD::addressof(__first->__value_));
+                __node_traits::deallocate(__a, __first, 1);
+                __first = __next;
+            }
+            throw;
+        }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        __last->__next_ = __r->__next_;
+        __r->__next_ = __first;
+        __r = __last;
+    }
+    return iterator(__r);
+}
+
+template <class _Tp, class _Alloc>
+typename forward_list<_Tp, _Alloc>::iterator
+forward_list<_Tp, _Alloc>::erase_after(const_iterator __f)
+{
+    __node_pointer __p = __f.__ptr_;
+    __node_pointer __n = __p->__next_;
+    __p->__next_ = __n->__next_;
+    __node_allocator& __a = base::__alloc();
+    __node_traits::destroy(__a, _VSTD::addressof(__n->__value_));
+    __node_traits::deallocate(__a, __n, 1);
+    return iterator(__p->__next_);
+}
+
+template <class _Tp, class _Alloc>
+typename forward_list<_Tp, _Alloc>::iterator
+forward_list<_Tp, _Alloc>::erase_after(const_iterator __f, const_iterator __l)
+{
+    __node_pointer __e = __l.__ptr_;
+    if (__f != __l)
+    {
+        __node_pointer __p = __f.__ptr_;
+        __node_pointer __n = __p->__next_;
+        if (__n != __e)
+        {
+            __p->__next_ = __e;
+            __node_allocator& __a = base::__alloc();
+            do
+            {
+                __p = __n->__next_;
+                __node_traits::destroy(__a, _VSTD::addressof(__n->__value_));
+                __node_traits::deallocate(__a, __n, 1);
+                __n = __p;
+            } while (__n != __e);
+        }
+    }
+    return iterator(__e);
+}
+
+template <class _Tp, class _Alloc>
+void
+forward_list<_Tp, _Alloc>::resize(size_type __n)
+{
+    size_type __sz = 0;
+    iterator __p = before_begin();
+    iterator __i = begin();
+    iterator __e = end();
+    for (; __i != __e && __sz < __n; ++__p, ++__i, ++__sz)
+        ;
+    if (__i != __e)
+        erase_after(__p, __e);
+    else
+    {
+        __n -= __sz;
+        if (__n > 0)
+        {
+            __node_allocator& __a = base::__alloc();
+            typedef __allocator_destructor<__node_allocator> _Dp;
+            unique_ptr<__node, _Dp> __h(nullptr, _Dp(__a, 1));
+            for (__node_pointer __ptr = __p.__ptr_; __n > 0; --__n,
+                                                         __ptr = __ptr->__next_)
+            {
+                __h.reset(__node_traits::allocate(__a, 1));
+                __node_traits::construct(__a, _VSTD::addressof(__h->__value_));
+                __h->__next_ = nullptr;
+                __ptr->__next_ = __h.release();
+            }
+        }
+    }
+}
+
+template <class _Tp, class _Alloc>
+void
+forward_list<_Tp, _Alloc>::resize(size_type __n, const value_type& __v)
+{
+    size_type __sz = 0;
+    iterator __p = before_begin();
+    iterator __i = begin();
+    iterator __e = end();
+    for (; __i != __e && __sz < __n; ++__p, ++__i, ++__sz)
+        ;
+    if (__i != __e)
+        erase_after(__p, __e);
+    else
+    {
+        __n -= __sz;
+        if (__n > 0)
+        {
+            __node_allocator& __a = base::__alloc();
+            typedef __allocator_destructor<__node_allocator> _Dp;
+            unique_ptr<__node, _Dp> __h(nullptr, _Dp(__a, 1));
+            for (__node_pointer __ptr = __p.__ptr_; __n > 0; --__n,
+                                                         __ptr = __ptr->__next_)
+            {
+                __h.reset(__node_traits::allocate(__a, 1));
+                __node_traits::construct(__a, _VSTD::addressof(__h->__value_), __v);
+                __h->__next_ = nullptr;
+                __ptr->__next_ = __h.release();
+            }
+        }
+    }
+}
+
+template <class _Tp, class _Alloc>
+void
+forward_list<_Tp, _Alloc>::splice_after(const_iterator __p,
+                                        forward_list& __x)
+{
+    if (!__x.empty())
+    {
+        if (__p.__ptr_->__next_ != nullptr)
+        {
+            const_iterator __lm1 = __x.before_begin();
+            while (__lm1.__ptr_->__next_ != nullptr)
+                ++__lm1;
+            __lm1.__ptr_->__next_ = __p.__ptr_->__next_;
+        }
+        __p.__ptr_->__next_ = __x.__before_begin()->__next_;
+        __x.__before_begin()->__next_ = nullptr;
+    }
+}
+
+template <class _Tp, class _Alloc>
+void
+forward_list<_Tp, _Alloc>::splice_after(const_iterator __p,
+                                        forward_list& __x,
+                                        const_iterator __i)
+{
+    const_iterator __lm1 = _VSTD::next(__i);
+    if (__p != __i && __p != __lm1)
+    {
+        __i.__ptr_->__next_ = __lm1.__ptr_->__next_;
+        __lm1.__ptr_->__next_ = __p.__ptr_->__next_;
+        __p.__ptr_->__next_ = __lm1.__ptr_;
+    }
+}
+
+template <class _Tp, class _Alloc>
+void
+forward_list<_Tp, _Alloc>::splice_after(const_iterator __p,
+                                        forward_list& __x,
+                                        const_iterator __f, const_iterator __l)
+{
+    if (__f != __l && __p != __f)
+    {
+        const_iterator __lm1 = __f;
+        while (__lm1.__ptr_->__next_ != __l.__ptr_)
+            ++__lm1;
+        if (__f != __lm1)
+        {
+            __lm1.__ptr_->__next_ = __p.__ptr_->__next_;
+            __p.__ptr_->__next_ = __f.__ptr_->__next_;
+            __f.__ptr_->__next_ = __l.__ptr_;
+        }
+    }
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+forward_list<_Tp, _Alloc>::splice_after(const_iterator __p,
+                                        forward_list&& __x)
+{
+    splice_after(__p, __x);
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+forward_list<_Tp, _Alloc>::splice_after(const_iterator __p,
+                                        forward_list&& __x,
+                                        const_iterator __i)
+{
+    splice_after(__p, __x, __i);
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+forward_list<_Tp, _Alloc>::splice_after(const_iterator __p,
+                                        forward_list&& __x,
+                                        const_iterator __f, const_iterator __l)
+{
+    splice_after(__p, __x, __f, __l);
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Alloc>
+void
+forward_list<_Tp, _Alloc>::remove(const value_type& __v)
+{
+    forward_list<_Tp, _Alloc> __deleted_nodes; // collect the nodes we're removing
+    iterator __e = end();
+    for (iterator __i = before_begin(); __i.__ptr_->__next_ != nullptr;)
+    {
+        if (__i.__ptr_->__next_->__value_ == __v)
+        {
+            iterator __j = _VSTD::next(__i, 2);
+            for (; __j != __e && *__j == __v; ++__j)
+                ;
+            __deleted_nodes.splice_after(__deleted_nodes.before_begin(), *this, __i, __j);
+            if (__j == __e)
+                break;
+            __i = __j;
+        }
+        else
+            ++__i;
+    }
+}
+
+template <class _Tp, class _Alloc>
+template <class _Predicate>
+void
+forward_list<_Tp, _Alloc>::remove_if(_Predicate __pred)
+{
+    iterator __e = end();
+    for (iterator __i = before_begin(); __i.__ptr_->__next_ != nullptr;)
+    {
+        if (__pred(__i.__ptr_->__next_->__value_))
+        {
+            iterator __j = _VSTD::next(__i, 2);
+            for (; __j != __e && __pred(*__j); ++__j)
+                ;
+            erase_after(__i, __j);
+            if (__j == __e)
+                break;
+            __i = __j;
+        }
+        else
+            ++__i;
+    }
+}
+
+template <class _Tp, class _Alloc>
+template <class _BinaryPredicate>
+void
+forward_list<_Tp, _Alloc>::unique(_BinaryPredicate __binary_pred)
+{
+    for (iterator __i = begin(), __e = end(); __i != __e;)
+    {
+        iterator __j = _VSTD::next(__i);
+        for (; __j != __e && __binary_pred(*__i, *__j); ++__j)
+            ;
+        if (__i.__ptr_->__next_ != __j.__ptr_)
+            erase_after(__i, __j);
+        __i = __j;
+    }
+}
+
+template <class _Tp, class _Alloc>
+template <class _Compare>
+void
+forward_list<_Tp, _Alloc>::merge(forward_list& __x, _Compare __comp)
+{
+    if (this != &__x)
+    {
+        base::__before_begin()->__next_ = __merge(base::__before_begin()->__next_,
+                                                    __x.__before_begin()->__next_,
+                                                    __comp);
+        __x.__before_begin()->__next_ = nullptr;
+    }
+}
+
+template <class _Tp, class _Alloc>
+template <class _Compare>
+typename forward_list<_Tp, _Alloc>::__node_pointer
+forward_list<_Tp, _Alloc>::__merge(__node_pointer __f1, __node_pointer __f2,
+                                   _Compare& __comp)
+{
+    if (__f1 == nullptr)
+        return __f2;
+    if (__f2 == nullptr)
+        return __f1;
+    __node_pointer __r;
+    if (__comp(__f2->__value_, __f1->__value_))
+    {
+        __node_pointer __t = __f2;
+        while (__t->__next_ != nullptr &&
+                             __comp(__t->__next_->__value_, __f1->__value_))
+            __t = __t->__next_;
+        __r = __f2;
+        __f2 = __t->__next_;
+        __t->__next_ = __f1;
+    }
+    else
+        __r = __f1;
+    __node_pointer __p = __f1;
+    __f1 = __f1->__next_;
+    while (__f1 != nullptr && __f2 != nullptr)
+    {
+        if (__comp(__f2->__value_, __f1->__value_))
+        {
+            __node_pointer __t = __f2;
+            while (__t->__next_ != nullptr &&
+                                 __comp(__t->__next_->__value_, __f1->__value_))
+                __t = __t->__next_;
+            __p->__next_ = __f2;
+            __f2 = __t->__next_;
+            __t->__next_ = __f1;
+        }
+        __p = __f1;
+        __f1 = __f1->__next_;
+    }
+    if (__f2 != nullptr)
+        __p->__next_ = __f2;
+    return __r;
+}
+
+template <class _Tp, class _Alloc>
+template <class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+forward_list<_Tp, _Alloc>::sort(_Compare __comp)
+{
+    base::__before_begin()->__next_ = __sort(base::__before_begin()->__next_,
+                                       _VSTD::distance(begin(), end()), __comp);
+}
+
+template <class _Tp, class _Alloc>
+template <class _Compare>
+typename forward_list<_Tp, _Alloc>::__node_pointer
+forward_list<_Tp, _Alloc>::__sort(__node_pointer __f1, difference_type __sz,
+                                  _Compare& __comp)
+{
+    switch (__sz)
+    {
+    case 0:
+    case 1:
+        return __f1;
+    case 2:
+        if (__comp(__f1->__next_->__value_, __f1->__value_))
+        {
+            __node_pointer __t = __f1->__next_;
+            __t->__next_ = __f1;
+            __f1->__next_ = nullptr;
+            __f1 = __t;
+        }
+        return __f1;
+    }
+    difference_type __sz1 = __sz / 2;
+    difference_type __sz2 = __sz - __sz1;
+    __node_pointer __t = _VSTD::next(iterator(__f1), __sz1 - 1).__ptr_;
+    __node_pointer __f2 = __t->__next_;
+    __t->__next_ = nullptr;
+    return __merge(__sort(__f1, __sz1, __comp),
+                   __sort(__f2, __sz2, __comp), __comp);
+}
+
+template <class _Tp, class _Alloc>
+void
+forward_list<_Tp, _Alloc>::reverse() _NOEXCEPT
+{
+    __node_pointer __p = base::__before_begin()->__next_;
+    if (__p != nullptr)
+    {
+        __node_pointer __f = __p->__next_;
+        __p->__next_ = nullptr;
+        while (__f != nullptr)
+        {
+            __node_pointer __t = __f->__next_;
+            __f->__next_ = __p;
+            __p = __f;
+            __f = __t;
+        }
+        base::__before_begin()->__next_ = __p;
+    }
+}
+
+template <class _Tp, class _Alloc>
+bool operator==(const forward_list<_Tp, _Alloc>& __x,
+                const forward_list<_Tp, _Alloc>& __y)
+{
+    typedef forward_list<_Tp, _Alloc> _Cp;
+    typedef typename _Cp::const_iterator _Ip;
+    _Ip __ix = __x.begin();
+    _Ip __ex = __x.end();
+    _Ip __iy = __y.begin();
+    _Ip __ey = __y.end();
+    for (; __ix != __ex && __iy != __ey; ++__ix, ++__iy)
+        if (!(*__ix == *__iy))
+            return false;
+    return (__ix == __ex) == (__iy == __ey);
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+bool operator!=(const forward_list<_Tp, _Alloc>& __x,
+                const forward_list<_Tp, _Alloc>& __y)
+{
+    return !(__x == __y);
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+bool operator< (const forward_list<_Tp, _Alloc>& __x,
+                const forward_list<_Tp, _Alloc>& __y)
+{
+    return _VSTD::lexicographical_compare(__x.begin(), __x.end(),
+                                         __y.begin(), __y.end());
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+bool operator> (const forward_list<_Tp, _Alloc>& __x,
+                const forward_list<_Tp, _Alloc>& __y)
+{
+    return __y < __x;
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+bool operator>=(const forward_list<_Tp, _Alloc>& __x,
+                const forward_list<_Tp, _Alloc>& __y)
+{
+    return !(__x < __y);
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+bool operator<=(const forward_list<_Tp, _Alloc>& __x,
+                const forward_list<_Tp, _Alloc>& __y)
+{
+    return !(__y < __x);
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(forward_list<_Tp, _Alloc>& __x, forward_list<_Tp, _Alloc>& __y)
+    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
+{
+    __x.swap(__y);
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_FORWARD_LIST

diff --git a/libcxx/include/fstream b/libcxx/include/fstream
new file mode 100644
index 0000000..1f289ed
--- /dev/null
+++ b/libcxx/include/fstream

@@ -0,0 +1,1457 @@
+// -*- C++ -*-
+//===------------------------- fstream ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_FSTREAM
+#define _LIBCPP_FSTREAM
+
+/*
+    fstream synopsis
+
+template <class charT, class traits = char_traits<charT> >
+class basic_filebuf
+    : public basic_streambuf<charT, traits>
+{
+public:
+    typedef charT                          char_type;
+    typedef traits                         traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    // 27.9.1.2 Constructors/destructor:
+    basic_filebuf();
+    basic_filebuf(basic_filebuf&& rhs);
+    virtual ~basic_filebuf();
+
+    // 27.9.1.3 Assign/swap:
+    basic_filebuf& operator=(basic_filebuf&& rhs);
+    void swap(basic_filebuf& rhs);
+
+    // 27.9.1.4 Members:
+    bool is_open() const;
+    basic_filebuf* open(const char* s, ios_base::openmode mode);
+    basic_filebuf* open(const string& s, ios_base::openmode mode);
+    basic_filebuf* close();
+
+protected:
+    // 27.9.1.5 Overridden virtual functions:
+    virtual streamsize showmanyc();
+    virtual int_type underflow();
+    virtual int_type uflow();
+    virtual int_type pbackfail(int_type c = traits_type::eof());
+    virtual int_type overflow (int_type c = traits_type::eof());
+    virtual basic_streambuf<char_type, traits_type>* setbuf(char_type* s, streamsize n);
+    virtual pos_type seekoff(off_type off, ios_base::seekdir way,
+                             ios_base::openmode which = ios_base::in | ios_base::out);
+    virtual pos_type seekpos(pos_type sp,
+                             ios_base::openmode which = ios_base::in | ios_base::out);
+    virtual int sync();
+    virtual void imbue(const locale& loc);
+};
+
+template <class charT, class traits>
+  void
+  swap(basic_filebuf<charT, traits>& x, basic_filebuf<charT, traits>& y);
+
+typedef basic_filebuf<char>    filebuf;
+typedef basic_filebuf<wchar_t> wfilebuf;
+
+template <class charT, class traits = char_traits<charT> >
+class basic_ifstream
+    : public basic_istream<charT,traits>
+{
+public:
+    typedef charT                          char_type;
+    typedef traits                         traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    basic_ifstream();
+    explicit basic_ifstream(const char* s, ios_base::openmode mode = ios_base::in);
+    explicit basic_ifstream(const string& s, ios_base::openmode mode = ios_base::in);
+    basic_ifstream(basic_ifstream&& rhs);
+
+    basic_ifstream& operator=(basic_ifstream&& rhs);
+    void swap(basic_ifstream& rhs);
+
+    basic_filebuf<char_type, traits_type>* rdbuf() const;
+    bool is_open() const;
+    void open(const char* s, ios_base::openmode mode = ios_base::in);
+    void open(const string& s, ios_base::openmode mode = ios_base::in);
+    void close();
+};
+
+template <class charT, class traits>
+  void
+  swap(basic_ifstream<charT, traits>& x, basic_ifstream<charT, traits>& y);
+
+typedef basic_ifstream<char>    ifstream;
+typedef basic_ifstream<wchar_t> wifstream;
+
+template <class charT, class traits = char_traits<charT> >
+class basic_ofstream
+    : public basic_ostream<charT,traits>
+{
+public:
+    typedef charT                          char_type;
+    typedef traits                         traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    basic_ofstream();
+    explicit basic_ofstream(const char* s, ios_base::openmode mode = ios_base::out);
+    explicit basic_ofstream(const string& s, ios_base::openmode mode = ios_base::out);
+    basic_ofstream(basic_ofstream&& rhs);
+
+    basic_ofstream& operator=(basic_ofstream&& rhs);
+    void swap(basic_ofstream& rhs);
+
+    basic_filebuf<char_type, traits_type>* rdbuf() const;
+    bool is_open() const;
+    void open(const char* s, ios_base::openmode mode = ios_base::out);
+    void open(const string& s, ios_base::openmode mode = ios_base::out);
+    void close();
+};
+
+template <class charT, class traits>
+  void
+  swap(basic_ofstream<charT, traits>& x, basic_ofstream<charT, traits>& y);
+
+typedef basic_ofstream<char>    ofstream;
+typedef basic_ofstream<wchar_t> wofstream;
+
+template <class charT, class traits=char_traits<charT> >
+class basic_fstream
+    : public basic_iostream<charT,traits>
+{
+public:
+    typedef charT                          char_type;
+    typedef traits                         traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    basic_fstream();
+    explicit basic_fstream(const char* s, ios_base::openmode mode = ios_base::in|ios_base::out);
+    explicit basic_fstream(const string& s, ios_base::openmode mode = ios_base::in|ios_base::out);
+    basic_fstream(basic_fstream&& rhs);
+
+    basic_fstream& operator=(basic_fstream&& rhs);
+    void swap(basic_fstream& rhs);
+
+    basic_filebuf<char_type, traits_type>* rdbuf() const;
+    bool is_open() const;
+    void open(const char* s, ios_base::openmode mode = ios_base::in|ios_base::out);
+    void open(const string& s, ios_base::openmode mode = ios_base::in|ios_base::out);
+    void close();
+};
+
+template <class charT, class traits>
+  void swap(basic_fstream<charT, traits>& x, basic_fstream<charT, traits>& y);
+
+typedef basic_fstream<char>    fstream;
+typedef basic_fstream<wchar_t> wfstream;
+
+}  // std
+
+*/
+
+#include <__config>
+#include <ostream>
+#include <istream>
+#include <__locale>
+#include <cstdio>
+
+#include <__undef_min_max>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TYPE_VIS_ONLY basic_filebuf
+    : public basic_streambuf<_CharT, _Traits>
+{
+public:
+    typedef _CharT                           char_type;
+    typedef _Traits                          traits_type;
+    typedef typename traits_type::int_type   int_type;
+    typedef typename traits_type::pos_type   pos_type;
+    typedef typename traits_type::off_type   off_type;
+    typedef typename traits_type::state_type state_type;
+
+    // 27.9.1.2 Constructors/destructor:
+    basic_filebuf();
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    basic_filebuf(basic_filebuf&& __rhs);
+#endif
+    virtual ~basic_filebuf();
+
+    // 27.9.1.3 Assign/swap:
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    basic_filebuf& operator=(basic_filebuf&& __rhs);
+#endif
+    void swap(basic_filebuf& __rhs);
+
+    // 27.9.1.4 Members:
+    bool is_open() const;
+#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+    basic_filebuf* open(const char* __s, ios_base::openmode __mode);
+    basic_filebuf* open(const string& __s, ios_base::openmode __mode);
+#endif
+    basic_filebuf* close();
+
+protected:
+    // 27.9.1.5 Overridden virtual functions:
+    virtual int_type underflow();
+    virtual int_type pbackfail(int_type __c = traits_type::eof());
+    virtual int_type overflow (int_type __c = traits_type::eof());
+    virtual basic_streambuf<char_type, traits_type>* setbuf(char_type* __s, streamsize __n);
+    virtual pos_type seekoff(off_type __off, ios_base::seekdir __way,
+                             ios_base::openmode __wch = ios_base::in | ios_base::out);
+    virtual pos_type seekpos(pos_type __sp,
+                             ios_base::openmode __wch = ios_base::in | ios_base::out);
+    virtual int sync();
+    virtual void imbue(const locale& __loc);
+
+private:
+    char*       __extbuf_;
+    const char* __extbufnext_;
+    const char* __extbufend_;
+    char __extbuf_min_[8];
+    size_t __ebs_;
+    char_type* __intbuf_;
+    size_t __ibs_;
+    FILE* __file_;
+    const codecvt<char_type, char, state_type>* __cv_;
+    state_type __st_;
+    state_type __st_last_;
+    ios_base::openmode __om_;
+    ios_base::openmode __cm_;
+    bool __owns_eb_;
+    bool __owns_ib_;
+    bool __always_noconv_;
+
+    bool __read_mode();
+    void __write_mode();
+};
+
+template <class _CharT, class _Traits>
+basic_filebuf<_CharT, _Traits>::basic_filebuf()
+    : __extbuf_(0),
+      __extbufnext_(0),
+      __extbufend_(0),
+      __ebs_(0),
+      __intbuf_(0),
+      __ibs_(0),
+      __file_(0),
+      __cv_(nullptr),
+      __st_(),
+      __st_last_(),
+      __om_(0),
+      __cm_(0),
+      __owns_eb_(false),
+      __owns_ib_(false),
+      __always_noconv_(false)
+{
+    if (has_facet<codecvt<char_type, char, state_type> >(this->getloc()))
+    {
+        __cv_ = &use_facet<codecvt<char_type, char, state_type> >(this->getloc());
+        __always_noconv_ = __cv_->always_noconv();
+    }
+    setbuf(0, 4096);
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits>
+basic_filebuf<_CharT, _Traits>::basic_filebuf(basic_filebuf&& __rhs)
+    : basic_streambuf<_CharT, _Traits>(__rhs)
+{
+    if (__rhs.__extbuf_ == __rhs.__extbuf_min_)
+    {
+        __extbuf_ = __extbuf_min_;
+        __extbufnext_ = __extbuf_ + (__rhs.__extbufnext_ - __rhs.__extbuf_);
+        __extbufend_ = __extbuf_ + (__rhs.__extbufend_ - __rhs.__extbuf_);
+    }
+    else
+    {
+        __extbuf_ = __rhs.__extbuf_;
+        __extbufnext_ = __rhs.__extbufnext_;
+        __extbufend_ = __rhs.__extbufend_;
+    }
+    __ebs_ = __rhs.__ebs_;
+    __intbuf_ = __rhs.__intbuf_;
+    __ibs_ = __rhs.__ibs_;
+    __file_ = __rhs.__file_;
+    __cv_ = __rhs.__cv_;
+    __st_ = __rhs.__st_;
+    __st_last_ = __rhs.__st_last_;
+    __om_ = __rhs.__om_;
+    __cm_ = __rhs.__cm_;
+    __owns_eb_ = __rhs.__owns_eb_;
+    __owns_ib_ = __rhs.__owns_ib_;
+    __always_noconv_ = __rhs.__always_noconv_;
+    if (__rhs.pbase())
+    {
+        if (__rhs.pbase() == __rhs.__intbuf_)
+            this->setp(__intbuf_, __intbuf_ + (__rhs. epptr() - __rhs.pbase()));
+        else
+            this->setp((char_type*)__extbuf_,
+                       (char_type*)__extbuf_ + (__rhs. epptr() - __rhs.pbase()));
+        this->pbump(__rhs. pptr() - __rhs.pbase());
+    }
+    else if (__rhs.eback())
+    {
+        if (__rhs.eback() == __rhs.__intbuf_)
+            this->setg(__intbuf_, __intbuf_ + (__rhs.gptr() - __rhs.eback()),
+                                  __intbuf_ + (__rhs.egptr() - __rhs.eback()));
+        else
+            this->setg((char_type*)__extbuf_,
+                       (char_type*)__extbuf_ + (__rhs.gptr() - __rhs.eback()),
+                       (char_type*)__extbuf_ + (__rhs.egptr() - __rhs.eback()));
+    }
+    __rhs.__extbuf_ = 0;
+    __rhs.__extbufnext_ = 0;
+    __rhs.__extbufend_ = 0;
+    __rhs.__ebs_ = 0;
+    __rhs.__intbuf_ = 0;
+    __rhs.__ibs_ = 0;
+    __rhs.__file_ = 0;
+    __rhs.__st_ = state_type();
+    __rhs.__st_last_ = state_type();
+    __rhs.__om_ = 0;
+    __rhs.__cm_ = 0;
+    __rhs.__owns_eb_ = false;
+    __rhs.__owns_ib_ = false;
+    __rhs.setg(0, 0, 0);
+    __rhs.setp(0, 0);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_filebuf<_CharT, _Traits>&
+basic_filebuf<_CharT, _Traits>::operator=(basic_filebuf&& __rhs)
+{
+    close();
+    swap(__rhs);
+    return *this;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits>
+basic_filebuf<_CharT, _Traits>::~basic_filebuf()
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        close();
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    if (__owns_eb_)
+        delete [] __extbuf_;
+    if (__owns_ib_)
+        delete [] __intbuf_;
+}
+
+template <class _CharT, class _Traits>
+void
+basic_filebuf<_CharT, _Traits>::swap(basic_filebuf& __rhs)
+{
+    basic_streambuf<char_type, traits_type>::swap(__rhs);
+    if (__extbuf_ != __extbuf_min_ && __rhs.__extbuf_ != __rhs.__extbuf_min_)
+    {
+        _VSTD::swap(__extbuf_, __rhs.__extbuf_);
+        _VSTD::swap(__extbufnext_, __rhs.__extbufnext_);
+        _VSTD::swap(__extbufend_, __rhs.__extbufend_);
+    }
+    else
+    {
+        ptrdiff_t __ln = __extbufnext_ - __extbuf_;
+        ptrdiff_t __le = __extbufend_ - __extbuf_;
+        ptrdiff_t __rn = __rhs.__extbufnext_ - __rhs.__extbuf_;
+        ptrdiff_t __re = __rhs.__extbufend_ - __rhs.__extbuf_;
+        if (__extbuf_ == __extbuf_min_ && __rhs.__extbuf_ != __rhs.__extbuf_min_)
+        {
+            __extbuf_ = __rhs.__extbuf_;
+            __rhs.__extbuf_ = __rhs.__extbuf_min_;
+        }
+        else if (__extbuf_ != __extbuf_min_ && __rhs.__extbuf_ == __rhs.__extbuf_min_)
+        {
+            __rhs.__extbuf_ = __extbuf_;
+            __extbuf_ = __extbuf_min_;
+        }
+        __extbufnext_ = __extbuf_ + __rn;
+        __extbufend_ = __extbuf_ + __re;
+        __rhs.__extbufnext_ = __rhs.__extbuf_ + __ln;
+        __rhs.__extbufend_ = __rhs.__extbuf_ + __le;
+    }
+    _VSTD::swap(__ebs_, __rhs.__ebs_);
+    _VSTD::swap(__intbuf_, __rhs.__intbuf_);
+    _VSTD::swap(__ibs_, __rhs.__ibs_);
+    _VSTD::swap(__file_, __rhs.__file_);
+    _VSTD::swap(__cv_, __rhs.__cv_);
+    _VSTD::swap(__st_, __rhs.__st_);
+    _VSTD::swap(__st_last_, __rhs.__st_last_);
+    _VSTD::swap(__om_, __rhs.__om_);
+    _VSTD::swap(__cm_, __rhs.__cm_);
+    _VSTD::swap(__owns_eb_, __rhs.__owns_eb_);
+    _VSTD::swap(__owns_ib_, __rhs.__owns_ib_);
+    _VSTD::swap(__always_noconv_, __rhs.__always_noconv_);
+    if (this->eback() == (char_type*)__rhs.__extbuf_min_)
+    {
+        ptrdiff_t __n = this->gptr() - this->eback();
+        ptrdiff_t __e = this->egptr() - this->eback();
+        this->setg((char_type*)__extbuf_min_,
+                   (char_type*)__extbuf_min_ + __n,
+                   (char_type*)__extbuf_min_ + __e);
+    }
+    else if (this->pbase() == (char_type*)__rhs.__extbuf_min_)
+    {
+        ptrdiff_t __n = this->pptr() - this->pbase();
+        ptrdiff_t __e = this->epptr() - this->pbase();
+        this->setp((char_type*)__extbuf_min_,
+                   (char_type*)__extbuf_min_ + __e);
+        this->pbump(__n);
+    }
+    if (__rhs.eback() == (char_type*)__extbuf_min_)
+    {
+        ptrdiff_t __n = __rhs.gptr() - __rhs.eback();
+        ptrdiff_t __e = __rhs.egptr() - __rhs.eback();
+        __rhs.setg((char_type*)__rhs.__extbuf_min_,
+                   (char_type*)__rhs.__extbuf_min_ + __n,
+                   (char_type*)__rhs.__extbuf_min_ + __e);
+    }
+    else if (__rhs.pbase() == (char_type*)__extbuf_min_)
+    {
+        ptrdiff_t __n = __rhs.pptr() - __rhs.pbase();
+        ptrdiff_t __e = __rhs.epptr() - __rhs.pbase();
+        __rhs.setp((char_type*)__rhs.__extbuf_min_,
+                   (char_type*)__rhs.__extbuf_min_ + __e);
+        __rhs.pbump(__n);
+    }
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(basic_filebuf<_CharT, _Traits>& __x, basic_filebuf<_CharT, _Traits>& __y)
+{
+    __x.swap(__y);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+basic_filebuf<_CharT, _Traits>::is_open() const
+{
+    return __file_ != 0;
+}
+
+#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+template <class _CharT, class _Traits>
+basic_filebuf<_CharT, _Traits>*
+basic_filebuf<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
+{
+    basic_filebuf<_CharT, _Traits>* __rt = 0;
+    if (__file_ == 0)
+    {
+        __rt = this;
+        const char* __mdstr;
+        switch (__mode & ~ios_base::ate)
+        {
+        case ios_base::out:
+        case ios_base::out | ios_base::trunc:
+            __mdstr = "w";
+            break;
+        case ios_base::out | ios_base::app:
+        case ios_base::app:
+            __mdstr = "a";
+            break;
+        case ios_base::in:
+            __mdstr = "r";
+            break;
+        case ios_base::in | ios_base::out:
+            __mdstr = "r+";
+            break;
+        case ios_base::in | ios_base::out | ios_base::trunc:
+            __mdstr = "w+";
+            break;
+        case ios_base::in | ios_base::out | ios_base::app:
+        case ios_base::in | ios_base::app:
+            __mdstr = "a+";
+            break;
+        case ios_base::out | ios_base::binary:
+        case ios_base::out | ios_base::trunc | ios_base::binary:
+            __mdstr = "wb";
+            break;
+        case ios_base::out | ios_base::app | ios_base::binary:
+        case ios_base::app | ios_base::binary:
+            __mdstr = "ab";
+            break;
+        case ios_base::in | ios_base::binary:
+            __mdstr = "rb";
+            break;
+        case ios_base::in | ios_base::out | ios_base::binary:
+            __mdstr = "r+b";
+            break;
+        case ios_base::in | ios_base::out | ios_base::trunc | ios_base::binary:
+            __mdstr = "w+b";
+            break;
+        case ios_base::in | ios_base::out | ios_base::app | ios_base::binary:
+        case ios_base::in | ios_base::app | ios_base::binary:
+            __mdstr = "a+b";
+            break;
+        default:
+            __rt = 0;
+            break;
+        }
+        if (__rt)
+        {
+            __file_ = fopen(__s, __mdstr);
+            if (__file_)
+            {
+                __om_ = __mode;
+                if (__mode & ios_base::ate)
+                {
+                    if (fseek(__file_, 0, SEEK_END))
+                    {
+                        fclose(__file_);
+                        __file_ = 0;
+                        __rt = 0;
+                    }
+                }
+            }
+            else
+                __rt = 0;
+        }
+    }
+    return __rt;
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_filebuf<_CharT, _Traits>*
+basic_filebuf<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
+{
+    return open(__s.c_str(), __mode);
+}
+#endif
+
+template <class _CharT, class _Traits>
+basic_filebuf<_CharT, _Traits>*
+basic_filebuf<_CharT, _Traits>::close()
+{
+    basic_filebuf<_CharT, _Traits>* __rt = 0;
+    if (__file_)
+    {
+        __rt = this;
+        unique_ptr<FILE, int(*)(FILE*)> __h(__file_, fclose);
+        if (sync())
+            __rt = 0;
+        if (fclose(__h.release()) == 0)
+            __file_ = 0;
+        else
+            __rt = 0;
+    }
+    return __rt;
+}
+
+template <class _CharT, class _Traits>
+typename basic_filebuf<_CharT, _Traits>::int_type
+basic_filebuf<_CharT, _Traits>::underflow()
+{
+    if (__file_ == 0)
+        return traits_type::eof();
+    bool __initial = __read_mode();
+    char_type __1buf;
+    if (this->gptr() == 0)
+        this->setg(&__1buf, &__1buf+1, &__1buf+1);
+    const size_t __unget_sz = __initial ? 0 : min<size_t>((this->egptr() - this->eback()) / 2, 4);
+    int_type __c = traits_type::eof();
+    if (this->gptr() == this->egptr())
+    {
+        memmove(this->eback(), this->egptr() - __unget_sz, __unget_sz * sizeof(char_type));
+        if (__always_noconv_)
+        {
+            size_t __nmemb = static_cast<size_t>(this->egptr() - this->eback() - __unget_sz);
+            __nmemb = fread(this->eback() + __unget_sz, 1, __nmemb, __file_);
+            if (__nmemb != 0)
+            {
+                this->setg(this->eback(),
+                           this->eback() + __unget_sz,
+                           this->eback() + __unget_sz + __nmemb);
+                __c = traits_type::to_int_type(*this->gptr());
+            }
+        }
+        else
+        {
+            memmove(__extbuf_, __extbufnext_, __extbufend_ - __extbufnext_);
+            __extbufnext_ = __extbuf_ + (__extbufend_ - __extbufnext_);
+            __extbufend_ = __extbuf_ + (__extbuf_ == __extbuf_min_ ? sizeof(__extbuf_min_) : __ebs_);
+            size_t __nmemb = _VSTD::min(static_cast<size_t>(__ibs_ - __unget_sz),
+                                 static_cast<size_t>(__extbufend_ - __extbufnext_));
+            codecvt_base::result __r;
+            __st_last_ = __st_;
+            size_t __nr = fread((void*)__extbufnext_, 1, __nmemb, __file_);
+            if (__nr != 0)
+            {
+#ifndef _LIBCPP_NO_EXCEPTIONS
+                if (!__cv_)
+                    throw bad_cast();
+#endif
+                __extbufend_ = __extbufnext_ + __nr;
+                char_type*  __inext;
+                __r = __cv_->in(__st_, __extbuf_, __extbufend_, __extbufnext_,
+                                       this->eback() + __unget_sz,
+                                       this->eback() + __ibs_, __inext);
+                if (__r == codecvt_base::noconv)
+                {
+                    this->setg((char_type*)__extbuf_, (char_type*)__extbuf_, (char_type*)__extbufend_);
+                    __c = traits_type::to_int_type(*this->gptr());
+                }
+                else if (__inext != this->eback() + __unget_sz)
+                {
+                    this->setg(this->eback(), this->eback() + __unget_sz, __inext);
+                    __c = traits_type::to_int_type(*this->gptr());
+                }
+            }
+        }
+    }
+    else
+        __c = traits_type::to_int_type(*this->gptr());
+    if (this->eback() == &__1buf)
+        this->setg(0, 0, 0);
+    return __c;
+}
+
+template <class _CharT, class _Traits>
+typename basic_filebuf<_CharT, _Traits>::int_type
+basic_filebuf<_CharT, _Traits>::pbackfail(int_type __c)
+{
+    if (__file_ && this->eback() < this->gptr())
+    {
+        if (traits_type::eq_int_type(__c, traits_type::eof()))
+        {
+            this->gbump(-1);
+            return traits_type::not_eof(__c);
+        }
+        if ((__om_ & ios_base::out) ||
+            traits_type::eq(traits_type::to_char_type(__c), this->gptr()[-1]))
+        {
+            this->gbump(-1);
+            *this->gptr() = traits_type::to_char_type(__c);
+            return __c;
+        }
+    }
+    return traits_type::eof();
+}
+
+template <class _CharT, class _Traits>
+typename basic_filebuf<_CharT, _Traits>::int_type
+basic_filebuf<_CharT, _Traits>::overflow(int_type __c)
+{
+    if (__file_ == 0)
+        return traits_type::eof();
+    __write_mode();
+    char_type __1buf;
+    char_type* __pb_save = this->pbase();
+    char_type* __epb_save = this->epptr();
+    if (!traits_type::eq_int_type(__c, traits_type::eof()))
+    {
+        if (this->pptr() == 0)
+            this->setp(&__1buf, &__1buf+1);
+        *this->pptr() = traits_type::to_char_type(__c);
+        this->pbump(1);
+    }
+    if (this->pptr() != this->pbase())
+    {
+        if (__always_noconv_)
+        {
+            size_t __nmemb = static_cast<size_t>(this->pptr() - this->pbase());
+            if (fwrite(this->pbase(), sizeof(char_type), __nmemb, __file_) != __nmemb)
+                return traits_type::eof();
+        }
+        else
+        {
+            char* __extbe = __extbuf_;
+            codecvt_base::result __r;
+            do
+            {
+#ifndef _LIBCPP_NO_EXCEPTIONS
+                if (!__cv_)
+                    throw bad_cast();
+#endif
+                const char_type* __e;
+                __r = __cv_->out(__st_, this->pbase(), this->pptr(), __e,
+                                        __extbuf_, __extbuf_ + __ebs_, __extbe);
+                if (__e == this->pbase())
+                    return traits_type::eof();
+                if (__r == codecvt_base::noconv)
+                {
+                    size_t __nmemb = static_cast<size_t>(this->pptr() - this->pbase());
+                    if (fwrite(this->pbase(), 1, __nmemb, __file_) != __nmemb)
+                        return traits_type::eof();
+                }
+                else if (__r == codecvt_base::ok || __r == codecvt_base::partial)
+                {
+                    size_t __nmemb = static_cast<size_t>(__extbe - __extbuf_);
+                    if (fwrite(__extbuf_, 1, __nmemb, __file_) != __nmemb)
+                        return traits_type::eof();
+                    if (__r == codecvt_base::partial)
+                    {
+                        this->setp((char_type*)__e, this->pptr());
+                        this->pbump(this->epptr() - this->pbase());
+                    }
+                }
+                else
+                    return traits_type::eof();
+            } while (__r == codecvt_base::partial);
+        }
+        this->setp(__pb_save, __epb_save);
+    }
+    return traits_type::not_eof(__c);
+}
+
+template <class _CharT, class _Traits>
+basic_streambuf<_CharT, _Traits>*
+basic_filebuf<_CharT, _Traits>::setbuf(char_type* __s, streamsize __n)
+{
+    this->setg(0, 0, 0);
+    this->setp(0, 0);
+    if (__owns_eb_)
+        delete [] __extbuf_;
+    if (__owns_ib_)
+        delete [] __intbuf_;
+    __ebs_ = __n;
+    if (__ebs_ > sizeof(__extbuf_min_))
+    {
+        if (__always_noconv_ && __s)
+        {
+            __extbuf_ = (char*)__s;
+            __owns_eb_ = false;
+        }
+        else
+        {
+            __extbuf_ = new char[__ebs_];
+            __owns_eb_ = true;
+        }
+    }
+    else
+    {
+        __extbuf_ = __extbuf_min_;
+        __ebs_ = sizeof(__extbuf_min_);
+        __owns_eb_ = false;
+    }
+    if (!__always_noconv_)
+    {
+        __ibs_ = max<streamsize>(__n, sizeof(__extbuf_min_));
+        if (__s && __ibs_ >= sizeof(__extbuf_min_))
+        {
+            __intbuf_ = __s;
+            __owns_ib_ = false;
+        }
+        else
+        {
+            __intbuf_ = new char_type[__ibs_];
+            __owns_ib_ = true;
+        }
+    }
+    else
+    {
+        __ibs_ = 0;
+        __intbuf_ = 0;
+        __owns_ib_ = false;
+    }
+    return this;
+}
+
+template <class _CharT, class _Traits>
+typename basic_filebuf<_CharT, _Traits>::pos_type
+basic_filebuf<_CharT, _Traits>::seekoff(off_type __off, ios_base::seekdir __way,
+                                        ios_base::openmode)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (!__cv_)
+        throw bad_cast();
+#endif
+    int __width = __cv_->encoding();
+    if (__file_ == 0 || (__width <= 0 && __off != 0) || sync())
+        return pos_type(off_type(-1));
+    // __width > 0 || __off == 0
+    int __whence;
+    switch (__way)
+    {
+    case ios_base::beg:
+        __whence = SEEK_SET;
+        break;
+    case ios_base::cur:
+        __whence = SEEK_CUR;
+        break;
+    case ios_base::end:
+        __whence = SEEK_END;
+        break;
+    default:
+        return pos_type(off_type(-1));
+    }
+#if defined(_WIN32) || defined(_NEWLIB_VERSION)
+    if (fseek(__file_, __width > 0 ? __width * __off : 0, __whence))
+        return pos_type(off_type(-1));
+    pos_type __r = ftell(__file_);
+#else
+    if (fseeko(__file_, __width > 0 ? __width * __off : 0, __whence))
+        return pos_type(off_type(-1));
+    pos_type __r = ftello(__file_);
+#endif
+    __r.state(__st_);
+    return __r;
+}
+
+template <class _CharT, class _Traits>
+typename basic_filebuf<_CharT, _Traits>::pos_type
+basic_filebuf<_CharT, _Traits>::seekpos(pos_type __sp, ios_base::openmode)
+{
+    if (__file_ == 0 || sync())
+        return pos_type(off_type(-1));
+#if defined(_WIN32) || defined(_NEWLIB_VERSION)
+    if (fseek(__file_, __sp, SEEK_SET))
+        return pos_type(off_type(-1));
+#else
+    if (fseeko(__file_, __sp, SEEK_SET))
+        return pos_type(off_type(-1));
+#endif
+    __st_ = __sp.state();
+    return __sp;
+}
+
+template <class _CharT, class _Traits>
+int
+basic_filebuf<_CharT, _Traits>::sync()
+{
+    if (__file_ == 0)
+        return 0;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (!__cv_)
+        throw bad_cast();
+#endif
+    if (__cm_ & ios_base::out)
+    {
+        if (this->pptr() != this->pbase())
+            if (overflow() == traits_type::eof())
+                return -1;
+        codecvt_base::result __r;
+        do
+        {
+            char* __extbe;
+            __r = __cv_->unshift(__st_, __extbuf_, __extbuf_ + __ebs_, __extbe);
+            size_t __nmemb = static_cast<size_t>(__extbe - __extbuf_);
+            if (fwrite(__extbuf_, 1, __nmemb, __file_) != __nmemb)
+                return -1;
+        } while (__r == codecvt_base::partial);
+        if (__r == codecvt_base::error)
+            return -1;
+        if (fflush(__file_))
+            return -1;
+    }
+    else if (__cm_ & ios_base::in)
+    {
+        off_type __c;
+        state_type __state = __st_last_;
+        bool __update_st = false;
+        if (__always_noconv_)
+            __c = this->egptr() - this->gptr();
+        else
+        {
+            int __width = __cv_->encoding();
+            __c = __extbufend_ - __extbufnext_;
+            if (__width > 0)
+                __c += __width * (this->egptr() - this->gptr());
+            else
+            {
+                if (this->gptr() != this->egptr())
+                {
+                    const int __off =  __cv_->length(__state, __extbuf_,
+                                                     __extbufnext_,
+                                                     this->gptr() - this->eback());
+                    __c += __extbufnext_ - __extbuf_ - __off;
+                    __update_st = true;
+                }
+            }
+        }
+#if defined(_WIN32) || defined(_NEWLIB_VERSION)
+        if (fseek(__file_, -__c, SEEK_CUR))
+            return -1;
+#else
+        if (fseeko(__file_, -__c, SEEK_CUR))
+            return -1;
+#endif
+        if (__update_st)
+            __st_ = __state;
+        __extbufnext_ = __extbufend_ = __extbuf_;
+        this->setg(0, 0, 0);
+        __cm_ = 0;
+    }
+    return 0;
+}
+
+template <class _CharT, class _Traits>
+void
+basic_filebuf<_CharT, _Traits>::imbue(const locale& __loc)
+{
+    sync();
+    __cv_ = &use_facet<codecvt<char_type, char, state_type> >(__loc);
+    bool __old_anc = __always_noconv_;
+    __always_noconv_ = __cv_->always_noconv();
+    if (__old_anc != __always_noconv_)
+    {
+        this->setg(0, 0, 0);
+        this->setp(0, 0);
+        // invariant, char_type is char, else we couldn't get here
+        if (__always_noconv_)  // need to dump __intbuf_
+        {
+            if (__owns_eb_)
+                delete [] __extbuf_;
+            __owns_eb_ = __owns_ib_;
+            __ebs_ = __ibs_;
+            __extbuf_ = (char*)__intbuf_;
+            __ibs_ = 0;
+            __intbuf_ = 0;
+            __owns_ib_ = false;
+        }
+        else  // need to obtain an __intbuf_.
+        {     // If __extbuf_ is user-supplied, use it, else new __intbuf_
+            if (!__owns_eb_ && __extbuf_ != __extbuf_min_)
+            {
+                __ibs_ = __ebs_;
+                __intbuf_ = (char_type*)__extbuf_;
+                __owns_ib_ = false;
+                __extbuf_ = new char[__ebs_];
+                __owns_eb_ = true;
+            }
+            else
+            {
+                __ibs_ = __ebs_;
+                __intbuf_ = new char_type[__ibs_];
+                __owns_ib_ = true;
+            }
+        }
+    }
+}
+
+template <class _CharT, class _Traits>
+bool
+basic_filebuf<_CharT, _Traits>::__read_mode()
+{
+    if (!(__cm_ & ios_base::in))
+    {
+        this->setp(0, 0);
+        if (__always_noconv_)
+            this->setg((char_type*)__extbuf_,
+                       (char_type*)__extbuf_ + __ebs_,
+                       (char_type*)__extbuf_ + __ebs_);
+        else
+            this->setg(__intbuf_, __intbuf_ + __ibs_, __intbuf_ + __ibs_);
+        __cm_ = ios_base::in;
+        return true;
+    }
+    return false;
+}
+
+template <class _CharT, class _Traits>
+void
+basic_filebuf<_CharT, _Traits>::__write_mode()
+{
+    if (!(__cm_ & ios_base::out))
+    {
+        this->setg(0, 0, 0);
+        if (__ebs_ > sizeof(__extbuf_min_))
+        {
+            if (__always_noconv_)
+                this->setp((char_type*)__extbuf_,
+                           (char_type*)__extbuf_ + (__ebs_ - 1));
+            else
+                this->setp(__intbuf_, __intbuf_ + (__ibs_ - 1));
+        }
+        else
+            this->setp(0, 0);
+        __cm_ = ios_base::out;
+    }
+}
+
+// basic_ifstream
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TYPE_VIS_ONLY basic_ifstream
+    : public basic_istream<_CharT, _Traits>
+{
+public:
+    typedef _CharT                         char_type;
+    typedef _Traits                        traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    basic_ifstream();
+#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+    explicit basic_ifstream(const char* __s, ios_base::openmode __mode = ios_base::in);
+    explicit basic_ifstream(const string& __s, ios_base::openmode __mode = ios_base::in);
+#endif
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    basic_ifstream(basic_ifstream&& __rhs);
+#endif
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    basic_ifstream& operator=(basic_ifstream&& __rhs);
+#endif
+    void swap(basic_ifstream& __rhs);
+
+    basic_filebuf<char_type, traits_type>* rdbuf() const;
+    bool is_open() const;
+#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+    void open(const char* __s, ios_base::openmode __mode = ios_base::in);
+    void open(const string& __s, ios_base::openmode __mode = ios_base::in);
+#endif
+    void close();
+
+private:
+    basic_filebuf<char_type, traits_type> __sb_;
+};
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ifstream<_CharT, _Traits>::basic_ifstream()
+    : basic_istream<char_type, traits_type>(&__sb_)
+{
+}
+
+#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ifstream<_CharT, _Traits>::basic_ifstream(const char* __s, ios_base::openmode __mode)
+    : basic_istream<char_type, traits_type>(&__sb_)
+{
+    if (__sb_.open(__s, __mode | ios_base::in) == 0)
+        this->setstate(ios_base::failbit);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ifstream<_CharT, _Traits>::basic_ifstream(const string& __s, ios_base::openmode __mode)
+    : basic_istream<char_type, traits_type>(&__sb_)
+{
+    if (__sb_.open(__s, __mode | ios_base::in) == 0)
+        this->setstate(ios_base::failbit);
+}
+#endif
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ifstream<_CharT, _Traits>::basic_ifstream(basic_ifstream&& __rhs)
+    : basic_istream<char_type, traits_type>(_VSTD::move(__rhs)),
+      __sb_(_VSTD::move(__rhs.__sb_))
+{
+    this->set_rdbuf(&__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ifstream<_CharT, _Traits>&
+basic_ifstream<_CharT, _Traits>::operator=(basic_ifstream&& __rhs)
+{
+    basic_istream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
+    __sb_ = _VSTD::move(__rhs.__sb_);
+    return *this;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+basic_ifstream<_CharT, _Traits>::swap(basic_ifstream& __rhs)
+{
+    basic_istream<char_type, traits_type>::swap(__rhs);
+    __sb_.swap(__rhs.__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(basic_ifstream<_CharT, _Traits>& __x, basic_ifstream<_CharT, _Traits>& __y)
+{
+    __x.swap(__y);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_filebuf<_CharT, _Traits>*
+basic_ifstream<_CharT, _Traits>::rdbuf() const
+{
+    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+basic_ifstream<_CharT, _Traits>::is_open() const
+{
+    return __sb_.is_open();
+}
+
+#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+template <class _CharT, class _Traits>
+void
+basic_ifstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
+{
+    if (__sb_.open(__s, __mode | ios_base::in))
+        this->clear();
+    else
+        this->setstate(ios_base::failbit);
+}
+
+template <class _CharT, class _Traits>
+void
+basic_ifstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
+{
+    if (__sb_.open(__s, __mode | ios_base::in))
+        this->clear();
+    else
+        this->setstate(ios_base::failbit);
+}
+#endif
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+basic_ifstream<_CharT, _Traits>::close()
+{
+    if (__sb_.close() == 0)
+        this->setstate(ios_base::failbit);
+}
+
+// basic_ofstream
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TYPE_VIS_ONLY basic_ofstream
+    : public basic_ostream<_CharT, _Traits>
+{
+public:
+    typedef _CharT                         char_type;
+    typedef _Traits                        traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    basic_ofstream();
+    explicit basic_ofstream(const char* __s, ios_base::openmode __mode = ios_base::out);
+    explicit basic_ofstream(const string& __s, ios_base::openmode __mode = ios_base::out);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    basic_ofstream(basic_ofstream&& __rhs);
+#endif
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    basic_ofstream& operator=(basic_ofstream&& __rhs);
+#endif
+    void swap(basic_ofstream& __rhs);
+
+    basic_filebuf<char_type, traits_type>* rdbuf() const;
+    bool is_open() const;
+#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+    void open(const char* __s, ios_base::openmode __mode = ios_base::out);
+    void open(const string& __s, ios_base::openmode __mode = ios_base::out);
+#endif
+    void close();
+
+private:
+    basic_filebuf<char_type, traits_type> __sb_;
+};
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ofstream<_CharT, _Traits>::basic_ofstream()
+    : basic_ostream<char_type, traits_type>(&__sb_)
+{
+}
+
+#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ofstream<_CharT, _Traits>::basic_ofstream(const char* __s, ios_base::openmode __mode)
+    : basic_ostream<char_type, traits_type>(&__sb_)
+{
+    if (__sb_.open(__s, __mode | ios_base::out) == 0)
+        this->setstate(ios_base::failbit);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ofstream<_CharT, _Traits>::basic_ofstream(const string& __s, ios_base::openmode __mode)
+    : basic_ostream<char_type, traits_type>(&__sb_)
+{
+    if (__sb_.open(__s, __mode | ios_base::out) == 0)
+        this->setstate(ios_base::failbit);
+}
+#endif
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ofstream<_CharT, _Traits>::basic_ofstream(basic_ofstream&& __rhs)
+    : basic_ostream<char_type, traits_type>(_VSTD::move(__rhs)),
+      __sb_(_VSTD::move(__rhs.__sb_))
+{
+    this->set_rdbuf(&__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ofstream<_CharT, _Traits>&
+basic_ofstream<_CharT, _Traits>::operator=(basic_ofstream&& __rhs)
+{
+    basic_ostream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
+    __sb_ = _VSTD::move(__rhs.__sb_);
+    return *this;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+basic_ofstream<_CharT, _Traits>::swap(basic_ofstream& __rhs)
+{
+    basic_ostream<char_type, traits_type>::swap(__rhs);
+    __sb_.swap(__rhs.__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(basic_ofstream<_CharT, _Traits>& __x, basic_ofstream<_CharT, _Traits>& __y)
+{
+    __x.swap(__y);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_filebuf<_CharT, _Traits>*
+basic_ofstream<_CharT, _Traits>::rdbuf() const
+{
+    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+basic_ofstream<_CharT, _Traits>::is_open() const
+{
+    return __sb_.is_open();
+}
+
+#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+template <class _CharT, class _Traits>
+void
+basic_ofstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
+{
+    if (__sb_.open(__s, __mode | ios_base::out))
+        this->clear();
+    else
+        this->setstate(ios_base::failbit);
+}
+
+template <class _CharT, class _Traits>
+void
+basic_ofstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
+{
+    if (__sb_.open(__s, __mode | ios_base::out))
+        this->clear();
+    else
+        this->setstate(ios_base::failbit);
+}
+#endif
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+basic_ofstream<_CharT, _Traits>::close()
+{
+    if (__sb_.close() == 0)
+        this->setstate(ios_base::failbit);
+}
+
+// basic_fstream
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TYPE_VIS_ONLY basic_fstream
+    : public basic_iostream<_CharT, _Traits>
+{
+public:
+    typedef _CharT                         char_type;
+    typedef _Traits                        traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    basic_fstream();
+#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+    explicit basic_fstream(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
+    explicit basic_fstream(const string& __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
+#endif
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    basic_fstream(basic_fstream&& __rhs);
+#endif
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    basic_fstream& operator=(basic_fstream&& __rhs);
+#endif
+    void swap(basic_fstream& __rhs);
+
+    basic_filebuf<char_type, traits_type>* rdbuf() const;
+    bool is_open() const;
+#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+    void open(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
+    void open(const string& __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
+#endif
+    void close();
+
+private:
+    basic_filebuf<char_type, traits_type> __sb_;
+};
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_fstream<_CharT, _Traits>::basic_fstream()
+    : basic_iostream<char_type, traits_type>(&__sb_)
+{
+}
+
+#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_fstream<_CharT, _Traits>::basic_fstream(const char* __s, ios_base::openmode __mode)
+    : basic_iostream<char_type, traits_type>(&__sb_)
+{
+    if (__sb_.open(__s, __mode) == 0)
+        this->setstate(ios_base::failbit);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_fstream<_CharT, _Traits>::basic_fstream(const string& __s, ios_base::openmode __mode)
+    : basic_iostream<char_type, traits_type>(&__sb_)
+{
+    if (__sb_.open(__s, __mode) == 0)
+        this->setstate(ios_base::failbit);
+}
+#endif
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_fstream<_CharT, _Traits>::basic_fstream(basic_fstream&& __rhs)
+    : basic_iostream<char_type, traits_type>(_VSTD::move(__rhs)),
+      __sb_(_VSTD::move(__rhs.__sb_))
+{
+    this->set_rdbuf(&__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_fstream<_CharT, _Traits>&
+basic_fstream<_CharT, _Traits>::operator=(basic_fstream&& __rhs)
+{
+    basic_iostream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
+    __sb_ = _VSTD::move(__rhs.__sb_);
+    return *this;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+basic_fstream<_CharT, _Traits>::swap(basic_fstream& __rhs)
+{
+    basic_iostream<char_type, traits_type>::swap(__rhs);
+    __sb_.swap(__rhs.__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(basic_fstream<_CharT, _Traits>& __x, basic_fstream<_CharT, _Traits>& __y)
+{
+    __x.swap(__y);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_filebuf<_CharT, _Traits>*
+basic_fstream<_CharT, _Traits>::rdbuf() const
+{
+    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+basic_fstream<_CharT, _Traits>::is_open() const
+{
+    return __sb_.is_open();
+}
+
+#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
+template <class _CharT, class _Traits>
+void
+basic_fstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
+{
+    if (__sb_.open(__s, __mode))
+        this->clear();
+    else
+        this->setstate(ios_base::failbit);
+}
+
+template <class _CharT, class _Traits>
+void
+basic_fstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
+{
+    if (__sb_.open(__s, __mode))
+        this->clear();
+    else
+        this->setstate(ios_base::failbit);
+}
+#endif
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+basic_fstream<_CharT, _Traits>::close()
+{
+    if (__sb_.close() == 0)
+        this->setstate(ios_base::failbit);
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_FSTREAM

diff --git a/libcxx/include/functional b/libcxx/include/functional
new file mode 100644
index 0000000..6c57de0
--- /dev/null
+++ b/libcxx/include/functional

@@ -0,0 +1,2504 @@
+// -*- C++ -*-
+//===------------------------ functional ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_FUNCTIONAL
+#define _LIBCPP_FUNCTIONAL
+
+/*
+    functional synopsis
+
+namespace std
+{
+
+template <class Arg, class Result>
+struct unary_function
+{
+    typedef Arg    argument_type;
+    typedef Result result_type;
+};
+
+template <class Arg1, class Arg2, class Result>
+struct binary_function
+{
+    typedef Arg1   first_argument_type;
+    typedef Arg2   second_argument_type;
+    typedef Result result_type;
+};
+
+template <class T>
+class reference_wrapper
+    : public unary_function<T1, R> // if wrapping a unary functor
+    : public binary_function<T1, T2, R> // if wraping a binary functor
+{
+public:
+    // types
+    typedef T type;
+    typedef see below result_type; // Not always defined
+
+    // construct/copy/destroy
+    reference_wrapper(T&) noexcept;
+    reference_wrapper(T&&) = delete; // do not bind to temps
+    reference_wrapper(const reference_wrapper<T>& x) noexcept;
+
+    // assignment
+    reference_wrapper& operator=(const reference_wrapper<T>& x) noexcept;
+
+    // access
+    operator T& () const noexcept;
+    T& get() const noexcept;
+
+    // invoke
+    template <class... ArgTypes>
+      typename result_of<T&(ArgTypes&&...)>::type
+          operator() (ArgTypes&&...) const;
+};
+
+template <class T> reference_wrapper<T> ref(T& t) noexcept;
+template <class T> void ref(const T&& t) = delete;
+template <class T> reference_wrapper<T> ref(reference_wrapper<T>t) noexcept;
+
+template <class T> reference_wrapper<const T> cref(const T& t) noexcept;
+template <class T> void cref(const T&& t) = delete;
+template <class T> reference_wrapper<const T> cref(reference_wrapper<T> t) noexcept;
+
+template <class T> // <class T=void> in C++14
+struct plus : binary_function<T, T, T>
+{
+    T operator()(const T& x, const T& y) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct minus : binary_function<T, T, T>
+{
+    T operator()(const T& x, const T& y) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct multiplies : binary_function<T, T, T>
+{
+    T operator()(const T& x, const T& y) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct divides : binary_function<T, T, T>
+{
+    T operator()(const T& x, const T& y) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct modulus : binary_function<T, T, T>
+{
+    T operator()(const T& x, const T& y) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct negate : unary_function<T, T>
+{
+    T operator()(const T& x) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct equal_to : binary_function<T, T, bool>
+{
+    bool operator()(const T& x, const T& y) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct not_equal_to : binary_function<T, T, bool>
+{
+    bool operator()(const T& x, const T& y) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct greater : binary_function<T, T, bool>
+{
+    bool operator()(const T& x, const T& y) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct less : binary_function<T, T, bool>
+{
+    bool operator()(const T& x, const T& y) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct greater_equal : binary_function<T, T, bool>
+{
+    bool operator()(const T& x, const T& y) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct less_equal : binary_function<T, T, bool>
+{
+    bool operator()(const T& x, const T& y) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct logical_and : binary_function<T, T, bool>
+{
+    bool operator()(const T& x, const T& y) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct logical_or : binary_function<T, T, bool>
+{
+    bool operator()(const T& x, const T& y) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct logical_not : unary_function<T, bool>
+{
+    bool operator()(const T& x) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct bit_and : unary_function<T, bool>
+{
+    bool operator()(const T& x, const T& y) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct bit_or : unary_function<T, bool>
+{
+    bool operator()(const T& x, const T& y) const;
+};
+
+template <class T> // <class T=void> in C++14
+struct bit_xor : unary_function<T, bool>
+{
+    bool operator()(const T& x, const T& y) const;
+};
+
+template <class T=void> // C++14
+struct bit_xor : unary_function<T, bool>
+{
+    bool operator()(const T& x) const;
+};
+
+template <class Predicate>
+class unary_negate
+    : public unary_function<typename Predicate::argument_type, bool>
+{
+public:
+    explicit unary_negate(const Predicate& pred);
+    bool operator()(const typename Predicate::argument_type& x) const;
+};
+
+template <class Predicate> unary_negate<Predicate> not1(const Predicate& pred);
+
+template <class Predicate>
+class binary_negate
+    : public binary_function<typename Predicate::first_argument_type,
+                             typename Predicate::second_argument_type,
+                             bool>
+{
+public:
+    explicit binary_negate(const Predicate& pred);
+    bool operator()(const typename Predicate::first_argument_type& x,
+                    const typename Predicate::second_argument_type& y) const;
+};
+
+template <class Predicate> binary_negate<Predicate> not2(const Predicate& pred);
+
+template<class T> struct is_bind_expression;
+template<class T> struct is_placeholder;
+
+template<class Fn, class... BoundArgs>
+  unspecified bind(Fn&&, BoundArgs&&...);
+template<class R, class Fn, class... BoundArgs>
+  unspecified bind(Fn&&, BoundArgs&&...);
+
+namespace placeholders {
+  // M is the implementation-defined number of placeholders
+  extern unspecified _1;
+  extern unspecified _2;
+  .
+  .
+  .
+  extern unspecified _Mp;
+}
+
+template <class Operation>
+class binder1st
+    : public unary_function<typename Operation::second_argument_type,
+                            typename Operation::result_type>
+{
+protected:
+    Operation                               op;
+    typename Operation::first_argument_type value;
+public:
+    binder1st(const Operation& x, const typename Operation::first_argument_type y);
+    typename Operation::result_type operator()(      typename Operation::second_argument_type& x) const;
+    typename Operation::result_type operator()(const typename Operation::second_argument_type& x) const;
+};
+
+template <class Operation, class T>
+binder1st<Operation> bind1st(const Operation& op, const T& x);
+
+template <class Operation>
+class binder2nd
+    : public unary_function<typename Operation::first_argument_type,
+                            typename Operation::result_type>
+{
+protected:
+    Operation                                op;
+    typename Operation::second_argument_type value;
+public:
+    binder2nd(const Operation& x, const typename Operation::second_argument_type y);
+    typename Operation::result_type operator()(      typename Operation::first_argument_type& x) const;
+    typename Operation::result_type operator()(const typename Operation::first_argument_type& x) const;
+};
+
+template <class Operation, class T>
+binder2nd<Operation> bind2nd(const Operation& op, const T& x);
+
+template <class Arg, class Result>
+class pointer_to_unary_function : public unary_function<Arg, Result>
+{
+public:
+    explicit pointer_to_unary_function(Result (*f)(Arg));
+    Result operator()(Arg x) const;
+};
+
+template <class Arg, class Result>
+pointer_to_unary_function<Arg,Result> ptr_fun(Result (*f)(Arg));
+
+template <class Arg1, class Arg2, class Result>
+class pointer_to_binary_function : public binary_function<Arg1, Arg2, Result>
+{
+public:
+    explicit pointer_to_binary_function(Result (*f)(Arg1, Arg2));
+    Result operator()(Arg1 x, Arg2 y) const;
+};
+
+template <class Arg1, class Arg2, class Result>
+pointer_to_binary_function<Arg1,Arg2,Result> ptr_fun(Result (*f)(Arg1,Arg2));
+
+template<class S, class T>
+class mem_fun_t : public unary_function<T*, S>
+{
+public:
+    explicit mem_fun_t(S (T::*p)());
+    S operator()(T* p) const;
+};
+
+template<class S, class T, class A>
+class mem_fun1_t : public binary_function<T*, A, S>
+{
+public:
+    explicit mem_fun1_t(S (T::*p)(A));
+    S operator()(T* p, A x) const;
+};
+
+template<class S, class T>          mem_fun_t<S,T>    mem_fun(S (T::*f)());
+template<class S, class T, class A> mem_fun1_t<S,T,A> mem_fun(S (T::*f)(A));
+
+template<class S, class T>
+class mem_fun_ref_t : public unary_function<T, S>
+{
+public:
+    explicit mem_fun_ref_t(S (T::*p)());
+    S operator()(T& p) const;
+};
+
+template<class S, class T, class A>
+class mem_fun1_ref_t : public binary_function<T, A, S>
+{
+public:
+    explicit mem_fun1_ref_t(S (T::*p)(A));
+    S operator()(T& p, A x) const;
+};
+
+template<class S, class T>          mem_fun_ref_t<S,T>    mem_fun_ref(S (T::*f)());
+template<class S, class T, class A> mem_fun1_ref_t<S,T,A> mem_fun_ref(S (T::*f)(A));
+
+template <class S, class T>
+class const_mem_fun_t : public unary_function<const T*, S>
+{
+public:
+    explicit const_mem_fun_t(S (T::*p)() const);
+    S operator()(const T* p) const;
+};
+
+template <class S, class T, class A>
+class const_mem_fun1_t : public binary_function<const T*, A, S>
+{
+public:
+    explicit const_mem_fun1_t(S (T::*p)(A) const);
+    S operator()(const T* p, A x) const;
+};
+
+template <class S, class T>          const_mem_fun_t<S,T>    mem_fun(S (T::*f)() const);
+template <class S, class T, class A> const_mem_fun1_t<S,T,A> mem_fun(S (T::*f)(A) const);
+
+template <class S, class T>
+class const_mem_fun_ref_t : public unary_function<T, S>
+{
+public:
+    explicit const_mem_fun_ref_t(S (T::*p)() const);
+    S operator()(const T& p) const;
+};
+
+template <class S, class T, class A>
+class const_mem_fun1_ref_t : public binary_function<T, A, S>
+{
+public:
+    explicit const_mem_fun1_ref_t(S (T::*p)(A) const);
+    S operator()(const T& p, A x) const;
+};
+
+template <class S, class T>          const_mem_fun_ref_t<S,T>    mem_fun_ref(S (T::*f)() const);
+template <class S, class T, class A> const_mem_fun1_ref_t<S,T,A> mem_fun_ref(S (T::*f)(A) const);
+
+template<class R, class T> unspecified mem_fn(R T::*);
+
+class bad_function_call
+    : public exception
+{
+};
+
+template<class> class function; // undefined
+
+template<class R, class... ArgTypes>
+class function<R(ArgTypes...)>
+  : public unary_function<T1, R>      // iff sizeof...(ArgTypes) == 1 and
+                                      // ArgTypes contains T1
+  : public binary_function<T1, T2, R> // iff sizeof...(ArgTypes) == 2 and
+                                      // ArgTypes contains T1 and T2
+{
+public:
+    typedef R result_type;
+
+    // construct/copy/destroy:
+    function() noexcept;
+    function(nullptr_t) noexcept;
+    function(const function&);
+    function(function&&) noexcept;
+    template<class F>
+      function(F);
+    template<Allocator Alloc>
+      function(allocator_arg_t, const Alloc&) noexcept;
+    template<Allocator Alloc>
+      function(allocator_arg_t, const Alloc&, nullptr_t) noexcept;
+    template<Allocator Alloc>
+      function(allocator_arg_t, const Alloc&, const function&);
+    template<Allocator Alloc>
+      function(allocator_arg_t, const Alloc&, function&&);
+    template<class F, Allocator Alloc>
+      function(allocator_arg_t, const Alloc&, F);
+
+    function& operator=(const function&);
+    function& operator=(function&&) noexcept;
+    function& operator=(nullptr_t) noexcept;
+    template<class F>
+      function& operator=(F&&);
+    template<class F>
+      function& operator=(reference_wrapper<F>) noexcept;
+
+    ~function();
+
+    // function modifiers:
+    void swap(function&) noexcept;
+    template<class F, class Alloc>
+      void assign(F&&, const Alloc&);
+
+    // function capacity:
+    explicit operator bool() const noexcept;
+
+    // function invocation:
+    R operator()(ArgTypes...) const;
+
+    // function target access:
+    const std::type_info& target_type() const noexcept;
+    template <typename T>       T* target() noexcept;
+    template <typename T> const T* target() const noexcept;
+};
+
+// Null pointer comparisons:
+template <class R, class ... ArgTypes>
+  bool operator==(const function<R(ArgTypes...)>&, nullptr_t) noexcept;
+
+template <class R, class ... ArgTypes>
+  bool operator==(nullptr_t, const function<R(ArgTypes...)>&) noexcept;
+
+template <class R, class ... ArgTypes>
+  bool operator!=(const function<R(ArgTypes...)>&, nullptr_t) noexcept;
+
+template <class  R, class ... ArgTypes>
+  bool operator!=(nullptr_t, const function<R(ArgTypes...)>&) noexcept;
+
+// specialized algorithms:
+template <class  R, class ... ArgTypes>
+  void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&) noexcept;
+
+template <class T> struct hash;
+
+template <> struct hash<bool>;
+template <> struct hash<char>;
+template <> struct hash<signed char>;
+template <> struct hash<unsigned char>;
+template <> struct hash<char16_t>;
+template <> struct hash<char32_t>;
+template <> struct hash<wchar_t>;
+template <> struct hash<short>;
+template <> struct hash<unsigned short>;
+template <> struct hash<int>;
+template <> struct hash<unsigned int>;
+template <> struct hash<long>;
+template <> struct hash<long long>;
+template <> struct hash<unsigned long>;
+template <> struct hash<unsigned long long>;
+
+template <> struct hash<float>;
+template <> struct hash<double>;
+template <> struct hash<long double>;
+
+template<class T> struct hash<T*>;
+
+}  // std
+
+POLICY:  For non-variadic implementations, the number of arguments is limited
+         to 3.  It is hoped that the need for non-variadic implementations
+         will be minimal.
+
+*/
+
+#include <__config>
+#include <type_traits>
+#include <typeinfo>
+#include <exception>
+#include <memory>
+#include <tuple>
+
+#include <__functional_base>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY plus : binary_function<_Tp, _Tp, _Tp>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _Tp operator()(const _Tp& __x, const _Tp& __y) const
+        {return __x + __y;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY plus<void>
+{
+    template <class _T1, class _T2>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_T1&& __t, _T2&& __u) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u)))
+    -> decltype        (_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u))
+        { return        _VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u); }
+    typedef void is_transparent;
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY minus : binary_function<_Tp, _Tp, _Tp>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _Tp operator()(const _Tp& __x, const _Tp& __y) const
+        {return __x - __y;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY minus<void>
+{
+    template <class _T1, class _T2>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_T1&& __t, _T2&& __u) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u)))
+    -> decltype        (_VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u))
+        { return        _VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u); }
+    typedef void is_transparent;
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY multiplies : binary_function<_Tp, _Tp, _Tp>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _Tp operator()(const _Tp& __x, const _Tp& __y) const
+        {return __x * __y;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY multiplies<void>
+{
+    template <class _T1, class _T2>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_T1&& __t, _T2&& __u) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u)))
+    -> decltype        (_VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u))
+        { return        _VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u); }
+    typedef void is_transparent;
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY divides : binary_function<_Tp, _Tp, _Tp>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _Tp operator()(const _Tp& __x, const _Tp& __y) const
+        {return __x / __y;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY divides<void>
+{
+    template <class _T1, class _T2>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_T1&& __t, _T2&& __u) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u)))
+    -> decltype        (_VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u))
+        { return        _VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u); }
+    typedef void is_transparent;
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY modulus : binary_function<_Tp, _Tp, _Tp>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _Tp operator()(const _Tp& __x, const _Tp& __y) const
+        {return __x % __y;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY modulus<void>
+{
+    template <class _T1, class _T2>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_T1&& __t, _T2&& __u) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u)))
+    -> decltype        (_VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u))
+        { return        _VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u); }
+    typedef void is_transparent;
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY negate : unary_function<_Tp, _Tp>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _Tp operator()(const _Tp& __x) const
+        {return -__x;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY negate<void>
+{
+    template <class _Tp>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_Tp&& __x) const
+    _NOEXCEPT_(noexcept(- _VSTD::forward<_Tp>(__x)))
+    -> decltype        (- _VSTD::forward<_Tp>(__x))
+        { return        - _VSTD::forward<_Tp>(__x); }
+    typedef void is_transparent;
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY equal_to : binary_function<_Tp, _Tp, bool>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _Tp& __x, const _Tp& __y) const
+        {return __x == __y;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY equal_to<void>
+{
+    template <class _T1, class _T2>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_T1&& __t, _T2&& __u) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u)))
+    -> decltype        (_VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u))
+        { return        _VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u); }
+    typedef void is_transparent;
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY not_equal_to : binary_function<_Tp, _Tp, bool>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _Tp& __x, const _Tp& __y) const
+        {return __x != __y;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY not_equal_to<void>
+{
+    template <class _T1, class _T2>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_T1&& __t, _T2&& __u) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u)))
+    -> decltype        (_VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u))
+        { return        _VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u); }
+    typedef void is_transparent;
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY greater : binary_function<_Tp, _Tp, bool>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _Tp& __x, const _Tp& __y) const
+        {return __x > __y;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY greater<void>
+{
+    template <class _T1, class _T2>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_T1&& __t, _T2&& __u) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u)))
+    -> decltype        (_VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u))
+        { return        _VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u); }
+    typedef void is_transparent;
+};
+#endif
+
+
+// less in <__functional_base>
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY greater_equal : binary_function<_Tp, _Tp, bool>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _Tp& __x, const _Tp& __y) const
+        {return __x >= __y;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY greater_equal<void>
+{
+    template <class _T1, class _T2>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_T1&& __t, _T2&& __u) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u)))
+    -> decltype        (_VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u))
+        { return        _VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u); }
+    typedef void is_transparent;
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY less_equal : binary_function<_Tp, _Tp, bool>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _Tp& __x, const _Tp& __y) const
+        {return __x <= __y;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY less_equal<void>
+{
+    template <class _T1, class _T2>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_T1&& __t, _T2&& __u) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u)))
+    -> decltype        (_VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u))
+        { return        _VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u); }
+    typedef void is_transparent;
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY logical_and : binary_function<_Tp, _Tp, bool>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _Tp& __x, const _Tp& __y) const
+        {return __x && __y;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY logical_and<void>
+{
+    template <class _T1, class _T2>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_T1&& __t, _T2&& __u) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u)))
+    -> decltype        (_VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u))
+        { return        _VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u); }
+    typedef void is_transparent;
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY logical_or : binary_function<_Tp, _Tp, bool>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _Tp& __x, const _Tp& __y) const
+        {return __x || __y;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY logical_or<void>
+{
+    template <class _T1, class _T2>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_T1&& __t, _T2&& __u) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u)))
+    -> decltype        (_VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u))
+        { return        _VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u); }
+    typedef void is_transparent;
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY logical_not : unary_function<_Tp, bool>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _Tp& __x) const
+        {return !__x;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY logical_not<void>
+{
+    template <class _Tp>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_Tp&& __x) const
+    _NOEXCEPT_(noexcept(!_VSTD::forward<_Tp>(__x)))
+    -> decltype        (!_VSTD::forward<_Tp>(__x))
+        { return        !_VSTD::forward<_Tp>(__x); }
+    typedef void is_transparent;
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY bit_and : binary_function<_Tp, _Tp, _Tp>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _Tp operator()(const _Tp& __x, const _Tp& __y) const
+        {return __x & __y;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY bit_and<void>
+{
+    template <class _T1, class _T2>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_T1&& __t, _T2&& __u) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u)))
+    -> decltype        (_VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u))
+        { return        _VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u); }
+    typedef void is_transparent;
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY bit_or : binary_function<_Tp, _Tp, _Tp>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _Tp operator()(const _Tp& __x, const _Tp& __y) const
+        {return __x | __y;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY bit_or<void>
+{
+    template <class _T1, class _T2>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_T1&& __t, _T2&& __u) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u)))
+    -> decltype        (_VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u))
+        { return        _VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u); }
+    typedef void is_transparent;
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+#else
+template <class _Tp>
+#endif
+struct _LIBCPP_TYPE_VIS_ONLY bit_xor : binary_function<_Tp, _Tp, _Tp>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _Tp operator()(const _Tp& __x, const _Tp& __y) const
+        {return __x ^ __y;}
+};
+
+#if _LIBCPP_STD_VER > 11
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY bit_xor<void>
+{
+    template <class _T1, class _T2>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_T1&& __t, _T2&& __u) const
+    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u)))
+    -> decltype        (_VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u))
+        { return        _VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u); }
+    typedef void is_transparent;
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp = void>
+struct _LIBCPP_TYPE_VIS_ONLY bit_not : unary_function<_Tp, _Tp>
+{
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    _Tp operator()(const _Tp& __x) const
+        {return ~__x;}
+};
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY bit_not<void>
+{
+    template <class _Tp>
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    auto operator()(_Tp&& __x) const
+    _NOEXCEPT_(noexcept(~_VSTD::forward<_Tp>(__x)))
+    -> decltype        (~_VSTD::forward<_Tp>(__x))
+        { return        ~_VSTD::forward<_Tp>(__x); }
+    typedef void is_transparent;
+};
+#endif
+
+template <class _Predicate>
+class _LIBCPP_TYPE_VIS_ONLY unary_negate
+    : public unary_function<typename _Predicate::argument_type, bool>
+{
+    _Predicate __pred_;
+public:
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    explicit unary_negate(const _Predicate& __pred)
+        : __pred_(__pred) {}
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const typename _Predicate::argument_type& __x) const
+        {return !__pred_(__x);}
+};
+
+template <class _Predicate>
+inline _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+unary_negate<_Predicate>
+not1(const _Predicate& __pred) {return unary_negate<_Predicate>(__pred);}
+
+template <class _Predicate>
+class _LIBCPP_TYPE_VIS_ONLY binary_negate
+    : public binary_function<typename _Predicate::first_argument_type,
+                             typename _Predicate::second_argument_type,
+                             bool>
+{
+    _Predicate __pred_;
+public:
+    _LIBCPP_INLINE_VISIBILITY explicit _LIBCPP_CONSTEXPR_AFTER_CXX11 
+    binary_negate(const _Predicate& __pred) : __pred_(__pred) {}
+
+    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const typename _Predicate::first_argument_type& __x,
+                    const typename _Predicate::second_argument_type& __y) const
+        {return !__pred_(__x, __y);}
+};
+
+template <class _Predicate>
+inline _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
+binary_negate<_Predicate>
+not2(const _Predicate& __pred) {return binary_negate<_Predicate>(__pred);}
+
+template <class __Operation>
+class _LIBCPP_TYPE_VIS_ONLY binder1st
+    : public unary_function<typename __Operation::second_argument_type,
+                            typename __Operation::result_type>
+{
+protected:
+    __Operation                               op;
+    typename __Operation::first_argument_type value;
+public:
+    _LIBCPP_INLINE_VISIBILITY binder1st(const __Operation& __x,
+                               const typename __Operation::first_argument_type __y)
+        : op(__x), value(__y) {}
+    _LIBCPP_INLINE_VISIBILITY typename __Operation::result_type operator()
+        (typename __Operation::second_argument_type& __x) const
+            {return op(value, __x);}
+    _LIBCPP_INLINE_VISIBILITY typename __Operation::result_type operator()
+        (const typename __Operation::second_argument_type& __x) const
+            {return op(value, __x);}
+};
+
+template <class __Operation, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+binder1st<__Operation>
+bind1st(const __Operation& __op, const _Tp& __x)
+    {return binder1st<__Operation>(__op, __x);}
+
+template <class __Operation>
+class _LIBCPP_TYPE_VIS_ONLY binder2nd
+    : public unary_function<typename __Operation::first_argument_type,
+                            typename __Operation::result_type>
+{
+protected:
+    __Operation                                op;
+    typename __Operation::second_argument_type value;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    binder2nd(const __Operation& __x, const typename __Operation::second_argument_type __y)
+        : op(__x), value(__y) {}
+    _LIBCPP_INLINE_VISIBILITY typename __Operation::result_type operator()
+        (      typename __Operation::first_argument_type& __x) const
+            {return op(__x, value);}
+    _LIBCPP_INLINE_VISIBILITY typename __Operation::result_type operator()
+        (const typename __Operation::first_argument_type& __x) const
+            {return op(__x, value);}
+};
+
+template <class __Operation, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+binder2nd<__Operation>
+bind2nd(const __Operation& __op, const _Tp& __x)
+    {return binder2nd<__Operation>(__op, __x);}
+
+template <class _Arg, class _Result>
+class _LIBCPP_TYPE_VIS_ONLY pointer_to_unary_function
+    : public unary_function<_Arg, _Result>
+{
+    _Result (*__f_)(_Arg);
+public:
+    _LIBCPP_INLINE_VISIBILITY explicit pointer_to_unary_function(_Result (*__f)(_Arg))
+        : __f_(__f) {}
+    _LIBCPP_INLINE_VISIBILITY _Result operator()(_Arg __x) const
+        {return __f_(__x);}
+};
+
+template <class _Arg, class _Result>
+inline _LIBCPP_INLINE_VISIBILITY
+pointer_to_unary_function<_Arg,_Result>
+ptr_fun(_Result (*__f)(_Arg))
+    {return pointer_to_unary_function<_Arg,_Result>(__f);}
+
+template <class _Arg1, class _Arg2, class _Result>
+class _LIBCPP_TYPE_VIS_ONLY pointer_to_binary_function
+    : public binary_function<_Arg1, _Arg2, _Result>
+{
+    _Result (*__f_)(_Arg1, _Arg2);
+public:
+    _LIBCPP_INLINE_VISIBILITY explicit pointer_to_binary_function(_Result (*__f)(_Arg1, _Arg2))
+        : __f_(__f) {}
+    _LIBCPP_INLINE_VISIBILITY _Result operator()(_Arg1 __x, _Arg2 __y) const
+        {return __f_(__x, __y);}
+};
+
+template <class _Arg1, class _Arg2, class _Result>
+inline _LIBCPP_INLINE_VISIBILITY
+pointer_to_binary_function<_Arg1,_Arg2,_Result>
+ptr_fun(_Result (*__f)(_Arg1,_Arg2))
+    {return pointer_to_binary_function<_Arg1,_Arg2,_Result>(__f);}
+
+template<class _Sp, class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY mem_fun_t : public unary_function<_Tp*, _Sp>
+{
+    _Sp (_Tp::*__p_)();
+public:
+    _LIBCPP_INLINE_VISIBILITY explicit mem_fun_t(_Sp (_Tp::*__p)())
+        : __p_(__p) {}
+    _LIBCPP_INLINE_VISIBILITY _Sp operator()(_Tp* __p) const
+        {return (__p->*__p_)();}
+};
+
+template<class _Sp, class _Tp, class _Ap>
+class _LIBCPP_TYPE_VIS_ONLY mem_fun1_t : public binary_function<_Tp*, _Ap, _Sp>
+{
+    _Sp (_Tp::*__p_)(_Ap);
+public:
+    _LIBCPP_INLINE_VISIBILITY explicit mem_fun1_t(_Sp (_Tp::*__p)(_Ap))
+        : __p_(__p) {}
+    _LIBCPP_INLINE_VISIBILITY _Sp operator()(_Tp* __p, _Ap __x) const
+        {return (__p->*__p_)(__x);}
+};
+
+template<class _Sp, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+mem_fun_t<_Sp,_Tp>
+mem_fun(_Sp (_Tp::*__f)())
+    {return mem_fun_t<_Sp,_Tp>(__f);}
+
+template<class _Sp, class _Tp, class _Ap>
+inline _LIBCPP_INLINE_VISIBILITY
+mem_fun1_t<_Sp,_Tp,_Ap>
+mem_fun(_Sp (_Tp::*__f)(_Ap))
+    {return mem_fun1_t<_Sp,_Tp,_Ap>(__f);}
+
+template<class _Sp, class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY mem_fun_ref_t : public unary_function<_Tp, _Sp>
+{
+    _Sp (_Tp::*__p_)();
+public:
+    _LIBCPP_INLINE_VISIBILITY explicit mem_fun_ref_t(_Sp (_Tp::*__p)())
+        : __p_(__p) {}
+    _LIBCPP_INLINE_VISIBILITY _Sp operator()(_Tp& __p) const
+        {return (__p.*__p_)();}
+};
+
+template<class _Sp, class _Tp, class _Ap>
+class _LIBCPP_TYPE_VIS_ONLY mem_fun1_ref_t : public binary_function<_Tp, _Ap, _Sp>
+{
+    _Sp (_Tp::*__p_)(_Ap);
+public:
+    _LIBCPP_INLINE_VISIBILITY explicit mem_fun1_ref_t(_Sp (_Tp::*__p)(_Ap))
+        : __p_(__p) {}
+    _LIBCPP_INLINE_VISIBILITY _Sp operator()(_Tp& __p, _Ap __x) const
+        {return (__p.*__p_)(__x);}
+};
+
+template<class _Sp, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+mem_fun_ref_t<_Sp,_Tp>
+mem_fun_ref(_Sp (_Tp::*__f)())
+    {return mem_fun_ref_t<_Sp,_Tp>(__f);}
+
+template<class _Sp, class _Tp, class _Ap>
+inline _LIBCPP_INLINE_VISIBILITY
+mem_fun1_ref_t<_Sp,_Tp,_Ap>
+mem_fun_ref(_Sp (_Tp::*__f)(_Ap))
+    {return mem_fun1_ref_t<_Sp,_Tp,_Ap>(__f);}
+
+template <class _Sp, class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY const_mem_fun_t : public unary_function<const _Tp*, _Sp>
+{
+    _Sp (_Tp::*__p_)() const;
+public:
+    _LIBCPP_INLINE_VISIBILITY explicit const_mem_fun_t(_Sp (_Tp::*__p)() const)
+        : __p_(__p) {}
+    _LIBCPP_INLINE_VISIBILITY _Sp operator()(const _Tp* __p) const
+        {return (__p->*__p_)();}
+};
+
+template <class _Sp, class _Tp, class _Ap>
+class _LIBCPP_TYPE_VIS_ONLY const_mem_fun1_t : public binary_function<const _Tp*, _Ap, _Sp>
+{
+    _Sp (_Tp::*__p_)(_Ap) const;
+public:
+    _LIBCPP_INLINE_VISIBILITY explicit const_mem_fun1_t(_Sp (_Tp::*__p)(_Ap) const)
+        : __p_(__p) {}
+    _LIBCPP_INLINE_VISIBILITY _Sp operator()(const _Tp* __p, _Ap __x) const
+        {return (__p->*__p_)(__x);}
+};
+
+template <class _Sp, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+const_mem_fun_t<_Sp,_Tp>
+mem_fun(_Sp (_Tp::*__f)() const)
+    {return const_mem_fun_t<_Sp,_Tp>(__f);}
+
+template <class _Sp, class _Tp, class _Ap>
+inline _LIBCPP_INLINE_VISIBILITY
+const_mem_fun1_t<_Sp,_Tp,_Ap>
+mem_fun(_Sp (_Tp::*__f)(_Ap) const)
+    {return const_mem_fun1_t<_Sp,_Tp,_Ap>(__f);}
+
+template <class _Sp, class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY const_mem_fun_ref_t : public unary_function<_Tp, _Sp>
+{
+    _Sp (_Tp::*__p_)() const;
+public:
+    _LIBCPP_INLINE_VISIBILITY explicit const_mem_fun_ref_t(_Sp (_Tp::*__p)() const)
+        : __p_(__p) {}
+    _LIBCPP_INLINE_VISIBILITY _Sp operator()(const _Tp& __p) const
+        {return (__p.*__p_)();}
+};
+
+template <class _Sp, class _Tp, class _Ap>
+class _LIBCPP_TYPE_VIS_ONLY const_mem_fun1_ref_t
+    : public binary_function<_Tp, _Ap, _Sp>
+{
+    _Sp (_Tp::*__p_)(_Ap) const;
+public:
+    _LIBCPP_INLINE_VISIBILITY explicit const_mem_fun1_ref_t(_Sp (_Tp::*__p)(_Ap) const)
+        : __p_(__p) {}
+    _LIBCPP_INLINE_VISIBILITY _Sp operator()(const _Tp& __p, _Ap __x) const
+        {return (__p.*__p_)(__x);}
+};
+
+template <class _Sp, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+const_mem_fun_ref_t<_Sp,_Tp>
+mem_fun_ref(_Sp (_Tp::*__f)() const)
+    {return const_mem_fun_ref_t<_Sp,_Tp>(__f);}
+
+template <class _Sp, class _Tp, class _Ap>
+inline _LIBCPP_INLINE_VISIBILITY
+const_mem_fun1_ref_t<_Sp,_Tp,_Ap>
+mem_fun_ref(_Sp (_Tp::*__f)(_Ap) const)
+    {return const_mem_fun1_ref_t<_Sp,_Tp,_Ap>(__f);}
+
+////////////////////////////////////////////////////////////////////////////////
+//                                MEMFUN
+//==============================================================================
+
+template <class _Tp>
+class __mem_fn
+    : public __weak_result_type<_Tp>
+{
+public:
+    // types
+    typedef _Tp type;
+private:
+    type __f_;
+
+public:
+    _LIBCPP_INLINE_VISIBILITY __mem_fn(type __f) : __f_(__f) {}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    // invoke
+    template <class... _ArgTypes>
+    _LIBCPP_INLINE_VISIBILITY
+    typename __invoke_return<type, _ArgTypes...>::type
+    operator() (_ArgTypes&&... __args) const {
+        return __invoke(__f_, _VSTD::forward<_ArgTypes>(__args)...);
+    }
+#else
+
+    template <class _A0>
+    typename __invoke_return0<type, _A0>::type
+    operator() (_A0& __a0) const {
+        return __invoke(__f_, __a0);
+    }
+
+    template <class _A0, class _A1>
+    typename __invoke_return1<type, _A0, _A1>::type
+    operator() (_A0& __a0, _A1& __a1) const {
+        return __invoke(__f_, __a0, __a1);
+    }
+
+    template <class _A0, class _A1, class _A2>
+    typename __invoke_return2<type, _A0, _A1, _A2>::type
+    operator() (_A0& __a0, _A1& __a1, _A2& __a2) const {
+        return __invoke(__f_, __a0, __a1, __a2);
+    }
+#endif
+};
+
+template<class _Rp, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+__mem_fn<_Rp _Tp::*>
+mem_fn(_Rp _Tp::* __pm)
+{
+    return __mem_fn<_Rp _Tp::*>(__pm);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+//                                FUNCTION
+//==============================================================================
+
+// bad_function_call
+
+class _LIBCPP_EXCEPTION_ABI bad_function_call
+    : public exception
+{
+};
+
+template<class _Fp> class _LIBCPP_TYPE_VIS_ONLY function; // undefined
+
+namespace __function
+{
+
+template<class _Rp>
+struct __maybe_derive_from_unary_function
+{
+};
+
+template<class _Rp, class _A1>
+struct __maybe_derive_from_unary_function<_Rp(_A1)>
+    : public unary_function<_A1, _Rp>
+{
+};
+
+template<class _Rp>
+struct __maybe_derive_from_binary_function
+{
+};
+
+template<class _Rp, class _A1, class _A2>
+struct __maybe_derive_from_binary_function<_Rp(_A1, _A2)>
+    : public binary_function<_A1, _A2, _Rp>
+{
+};
+
+} // namespace __function
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+namespace __function {
+
+template<class _Fp> class __base;
+
+template<class _Rp, class ..._ArgTypes>
+class __base<_Rp(_ArgTypes...)>
+{
+    __base(const __base&);
+    __base& operator=(const __base&);
+public:
+    _LIBCPP_INLINE_VISIBILITY __base() {}
+    _LIBCPP_INLINE_VISIBILITY virtual ~__base() {}
+    virtual __base* __clone() const = 0;
+    virtual void __clone(__base*) const = 0;
+    virtual void destroy() _NOEXCEPT = 0;
+    virtual void destroy_deallocate() _NOEXCEPT = 0;
+    virtual _Rp operator()(_ArgTypes&& ...) = 0;
+#ifndef _LIBCPP_NO_RTTI
+    virtual const void* target(const type_info&) const _NOEXCEPT = 0;
+    virtual const std::type_info& target_type() const _NOEXCEPT = 0;
+#endif  // _LIBCPP_NO_RTTI
+};
+
+template<class _FD, class _Alloc, class _FB> class __func;
+
+template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
+class __func<_Fp, _Alloc, _Rp(_ArgTypes...)>
+    : public  __base<_Rp(_ArgTypes...)>
+{
+    __compressed_pair<_Fp, _Alloc> __f_;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __func(_Fp&& __f)
+        : __f_(piecewise_construct, _VSTD::forward_as_tuple(_VSTD::move(__f)),
+                                    _VSTD::forward_as_tuple()) {}
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __func(const _Fp& __f, const _Alloc& __a)
+        : __f_(piecewise_construct, _VSTD::forward_as_tuple(__f),
+                                    _VSTD::forward_as_tuple(__a)) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __func(const _Fp& __f, _Alloc&& __a)
+        : __f_(piecewise_construct, _VSTD::forward_as_tuple(__f),
+                                    _VSTD::forward_as_tuple(_VSTD::move(__a))) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __func(_Fp&& __f, _Alloc&& __a)
+        : __f_(piecewise_construct, _VSTD::forward_as_tuple(_VSTD::move(__f)),
+                                    _VSTD::forward_as_tuple(_VSTD::move(__a))) {}
+    virtual __base<_Rp(_ArgTypes...)>* __clone() const;
+    virtual void __clone(__base<_Rp(_ArgTypes...)>*) const;
+    virtual void destroy() _NOEXCEPT;
+    virtual void destroy_deallocate() _NOEXCEPT;
+    virtual _Rp operator()(_ArgTypes&& ... __arg);
+#ifndef _LIBCPP_NO_RTTI
+    virtual const void* target(const type_info&) const _NOEXCEPT;
+    virtual const std::type_info& target_type() const _NOEXCEPT;
+#endif  // _LIBCPP_NO_RTTI
+};
+
+template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
+__base<_Rp(_ArgTypes...)>*
+__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::__clone() const
+{
+    typedef allocator_traits<_Alloc> __alloc_traits;
+    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
+    _Ap __a(__f_.second());
+    typedef __allocator_destructor<_Ap> _Dp;
+    unique_ptr<__func, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+    ::new (__hold.get()) __func(__f_.first(), _Alloc(__a));
+    return __hold.release();
+}
+
+template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
+void
+__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::__clone(__base<_Rp(_ArgTypes...)>* __p) const
+{
+    ::new (__p) __func(__f_.first(), __f_.second());
+}
+
+template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
+void
+__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::destroy() _NOEXCEPT
+{
+    __f_.~__compressed_pair<_Fp, _Alloc>();
+}
+
+template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
+void
+__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::destroy_deallocate() _NOEXCEPT
+{
+    typedef allocator_traits<_Alloc> __alloc_traits;
+    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
+    _Ap __a(__f_.second());
+    __f_.~__compressed_pair<_Fp, _Alloc>();
+    __a.deallocate(this, 1);
+}
+
+template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
+_Rp
+__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::operator()(_ArgTypes&& ... __arg)
+{
+    typedef __invoke_void_return_wrapper<_Rp> _Invoker;
+    return _Invoker::__call(__f_.first(), _VSTD::forward<_ArgTypes>(__arg)...);
+}
+
+#ifndef _LIBCPP_NO_RTTI
+
+template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
+const void*
+__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::target(const type_info& __ti) const _NOEXCEPT
+{
+    if (__ti == typeid(_Fp))
+        return &__f_.first();
+    return (const void*)0;
+}
+
+template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
+const std::type_info&
+__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::target_type() const _NOEXCEPT
+{
+    return typeid(_Fp);
+}
+
+#endif  // _LIBCPP_NO_RTTI
+
+}  // __function
+
+template<class _Rp, class ..._ArgTypes>
+class _LIBCPP_TYPE_VIS_ONLY function<_Rp(_ArgTypes...)>
+    : public __function::__maybe_derive_from_unary_function<_Rp(_ArgTypes...)>,
+      public __function::__maybe_derive_from_binary_function<_Rp(_ArgTypes...)>
+{
+    typedef __function::__base<_Rp(_ArgTypes...)> __base;
+    typename aligned_storage<3*sizeof(void*)>::type __buf_;
+    __base* __f_;
+
+    template <class _Fp>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(const _Fp&) {return true;}
+    template <class _R2, class ..._Ap>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (*__p)(_Ap...)) {return __p;}
+    template <class _R2, class _Cp, class ..._Ap>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (_Cp::*__p)(_Ap...)) {return __p;}
+    template <class _R2, class _Cp, class ..._Ap>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (_Cp::*__p)(_Ap...) const) {return __p;}
+    template <class _R2, class _Cp, class ..._Ap>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (_Cp::*__p)(_Ap...) volatile) {return __p;}
+    template <class _R2, class _Cp, class ..._Ap>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(_R2 (_Cp::*__p)(_Ap...) const volatile) {return __p;}
+    template <class _R2, class ..._Ap>
+        _LIBCPP_INLINE_VISIBILITY
+        static bool __not_null(const function<_R2(_Ap...)>& __p) {return !!__p;}
+
+    template <class _Fp, bool = !is_same<_Fp, function>::value &&
+                                __invokable<_Fp&, _ArgTypes...>::value>
+        struct __callable;
+    template <class _Fp>
+        struct __callable<_Fp, true>
+        {
+            static const bool value = is_same<void, _Rp>::value ||
+                is_convertible<typename __invoke_of<_Fp&, _ArgTypes...>::type,
+                               _Rp>::value;
+        };
+    template <class _Fp>
+        struct __callable<_Fp, false>
+        {
+            static const bool value = false;
+        };
+public:
+    typedef _Rp result_type;
+
+    // construct/copy/destroy:
+    _LIBCPP_INLINE_VISIBILITY
+    function() _NOEXCEPT : __f_(0) {}
+    _LIBCPP_INLINE_VISIBILITY
+    function(nullptr_t) _NOEXCEPT : __f_(0) {}
+    function(const function&);
+    function(function&&) _NOEXCEPT;
+    template<class _Fp>
+      function(_Fp, typename enable_if
+                                     <
+                                        __callable<_Fp>::value &&
+                                        !is_same<_Fp, function>::value
+                                      >::type* = 0);
+
+    template<class _Alloc>
+      _LIBCPP_INLINE_VISIBILITY
+      function(allocator_arg_t, const _Alloc&) _NOEXCEPT : __f_(0) {}
+    template<class _Alloc>
+      _LIBCPP_INLINE_VISIBILITY
+      function(allocator_arg_t, const _Alloc&, nullptr_t) _NOEXCEPT : __f_(0) {}
+    template<class _Alloc>
+      function(allocator_arg_t, const _Alloc&, const function&);
+    template<class _Alloc>
+      function(allocator_arg_t, const _Alloc&, function&&);
+    template<class _Fp, class _Alloc>
+      function(allocator_arg_t, const _Alloc& __a, _Fp __f,
+               typename enable_if<__callable<_Fp>::value>::type* = 0);
+
+    function& operator=(const function&);
+    function& operator=(function&&) _NOEXCEPT;
+    function& operator=(nullptr_t) _NOEXCEPT;
+    template<class _Fp>
+      typename enable_if
+      <
+        __callable<typename decay<_Fp>::type>::value &&
+        !is_same<typename remove_reference<_Fp>::type, function>::value,
+        function&
+      >::type
+      operator=(_Fp&&);
+
+    ~function();
+
+    // function modifiers:
+    void swap(function&) _NOEXCEPT;
+    template<class _Fp, class _Alloc>
+      _LIBCPP_INLINE_VISIBILITY
+      void assign(_Fp&& __f, const _Alloc& __a)
+        {function(allocator_arg, __a, _VSTD::forward<_Fp>(__f)).swap(*this);}
+
+    // function capacity:
+    _LIBCPP_INLINE_VISIBILITY
+        _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {return __f_;}
+
+    // deleted overloads close possible hole in the type system
+    template<class _R2, class... _ArgTypes2>
+      bool operator==(const function<_R2(_ArgTypes2...)>&) const = delete;
+    template<class _R2, class... _ArgTypes2>
+      bool operator!=(const function<_R2(_ArgTypes2...)>&) const = delete;
+public:
+    // function invocation:
+    _Rp operator()(_ArgTypes...) const;
+
+#ifndef _LIBCPP_NO_RTTI
+    // function target access:
+    const std::type_info& target_type() const _NOEXCEPT;
+    template <typename _Tp> _Tp* target() _NOEXCEPT;
+    template <typename _Tp> const _Tp* target() const _NOEXCEPT;
+#endif  // _LIBCPP_NO_RTTI
+};
+
+template<class _Rp, class ..._ArgTypes>
+function<_Rp(_ArgTypes...)>::function(const function& __f)
+{
+    if (__f.__f_ == 0)
+        __f_ = 0;
+    else if (__f.__f_ == (const __base*)&__f.__buf_)
+    {
+        __f_ = (__base*)&__buf_;
+        __f.__f_->__clone(__f_);
+    }
+    else
+        __f_ = __f.__f_->__clone();
+}
+
+template<class _Rp, class ..._ArgTypes>
+template <class _Alloc>
+function<_Rp(_ArgTypes...)>::function(allocator_arg_t, const _Alloc&,
+                                     const function& __f)
+{
+    if (__f.__f_ == 0)
+        __f_ = 0;
+    else if (__f.__f_ == (const __base*)&__f.__buf_)
+    {
+        __f_ = (__base*)&__buf_;
+        __f.__f_->__clone(__f_);
+    }
+    else
+        __f_ = __f.__f_->__clone();
+}
+
+template<class _Rp, class ..._ArgTypes>
+function<_Rp(_ArgTypes...)>::function(function&& __f) _NOEXCEPT
+{
+    if (__f.__f_ == 0)
+        __f_ = 0;
+    else if (__f.__f_ == (__base*)&__f.__buf_)
+    {
+        __f_ = (__base*)&__buf_;
+        __f.__f_->__clone(__f_);
+    }
+    else
+    {
+        __f_ = __f.__f_;
+        __f.__f_ = 0;
+    }
+}
+
+template<class _Rp, class ..._ArgTypes>
+template <class _Alloc>
+function<_Rp(_ArgTypes...)>::function(allocator_arg_t, const _Alloc&,
+                                     function&& __f)
+{
+    if (__f.__f_ == 0)
+        __f_ = 0;
+    else if (__f.__f_ == (__base*)&__f.__buf_)
+    {
+        __f_ = (__base*)&__buf_;
+        __f.__f_->__clone(__f_);
+    }
+    else
+    {
+        __f_ = __f.__f_;
+        __f.__f_ = 0;
+    }
+}
+
+template<class _Rp, class ..._ArgTypes>
+template <class _Fp>
+function<_Rp(_ArgTypes...)>::function(_Fp __f,
+                                     typename enable_if
+                                     <
+                                        __callable<_Fp>::value &&
+                                        !is_same<_Fp, function>::value
+                                     >::type*)
+    : __f_(0)
+{
+    if (__not_null(__f))
+    {
+        typedef __function::__func<_Fp, allocator<_Fp>, _Rp(_ArgTypes...)> _FF;
+        if (sizeof(_FF) <= sizeof(__buf_) && is_nothrow_copy_constructible<_Fp>::value)
+        {
+            __f_ = (__base*)&__buf_;
+            ::new (__f_) _FF(_VSTD::move(__f));
+        }
+        else
+        {
+            typedef allocator<_FF> _Ap;
+            _Ap __a;
+            typedef __allocator_destructor<_Ap> _Dp;
+            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+            ::new (__hold.get()) _FF(_VSTD::move(__f), allocator<_Fp>(__a));
+            __f_ = __hold.release();
+        }
+    }
+}
+
+template<class _Rp, class ..._ArgTypes>
+template <class _Fp, class _Alloc>
+function<_Rp(_ArgTypes...)>::function(allocator_arg_t, const _Alloc& __a0, _Fp __f,
+                                     typename enable_if<__callable<_Fp>::value>::type*)
+    : __f_(0)
+{
+    typedef allocator_traits<_Alloc> __alloc_traits;
+    if (__not_null(__f))
+    {
+        typedef __function::__func<_Fp, _Alloc, _Rp(_ArgTypes...)> _FF;
+        typedef typename __rebind_alloc_helper<__alloc_traits, _FF>::type _Ap;
+        _Ap __a(__a0);
+        if (sizeof(_FF) <= sizeof(__buf_) && 
+            is_nothrow_copy_constructible<_Fp>::value && is_nothrow_copy_constructible<_Ap>::value)
+        {
+            __f_ = (__base*)&__buf_;
+            ::new (__f_) _FF(_VSTD::move(__f), _Alloc(__a));
+        }
+        else
+        {
+            typedef __allocator_destructor<_Ap> _Dp;
+            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+            ::new (__hold.get()) _FF(_VSTD::move(__f), _Alloc(__a));
+            __f_ = __hold.release();
+        }
+    }
+}
+
+template<class _Rp, class ..._ArgTypes>
+function<_Rp(_ArgTypes...)>&
+function<_Rp(_ArgTypes...)>::operator=(const function& __f)
+{
+    function(__f).swap(*this);
+    return *this;
+}
+
+template<class _Rp, class ..._ArgTypes>
+function<_Rp(_ArgTypes...)>&
+function<_Rp(_ArgTypes...)>::operator=(function&& __f) _NOEXCEPT
+{
+    if (__f_ == (__base*)&__buf_)
+        __f_->destroy();
+    else if (__f_)
+        __f_->destroy_deallocate();
+    __f_ = 0;
+    if (__f.__f_ == 0)
+        __f_ = 0;
+    else if (__f.__f_ == (__base*)&__f.__buf_)
+    {
+        __f_ = (__base*)&__buf_;
+        __f.__f_->__clone(__f_);
+    }
+    else
+    {
+        __f_ = __f.__f_;
+        __f.__f_ = 0;
+    }
+    return *this;
+}
+
+template<class _Rp, class ..._ArgTypes>
+function<_Rp(_ArgTypes...)>&
+function<_Rp(_ArgTypes...)>::operator=(nullptr_t) _NOEXCEPT
+{
+    if (__f_ == (__base*)&__buf_)
+        __f_->destroy();
+    else if (__f_)
+        __f_->destroy_deallocate();
+    __f_ = 0;
+    return *this;
+}
+
+template<class _Rp, class ..._ArgTypes>
+template <class _Fp>
+typename enable_if
+<
+    function<_Rp(_ArgTypes...)>::template __callable<typename decay<_Fp>::type>::value &&
+    !is_same<typename remove_reference<_Fp>::type, function<_Rp(_ArgTypes...)>>::value,
+    function<_Rp(_ArgTypes...)>&
+>::type
+function<_Rp(_ArgTypes...)>::operator=(_Fp&& __f)
+{
+    function(_VSTD::forward<_Fp>(__f)).swap(*this);
+    return *this;
+}
+
+template<class _Rp, class ..._ArgTypes>
+function<_Rp(_ArgTypes...)>::~function()
+{
+    if (__f_ == (__base*)&__buf_)
+        __f_->destroy();
+    else if (__f_)
+        __f_->destroy_deallocate();
+}
+
+template<class _Rp, class ..._ArgTypes>
+void
+function<_Rp(_ArgTypes...)>::swap(function& __f) _NOEXCEPT
+{
+    if (__f_ == (__base*)&__buf_ && __f.__f_ == (__base*)&__f.__buf_)
+    {
+        typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
+        __base* __t = (__base*)&__tempbuf;
+        __f_->__clone(__t);
+        __f_->destroy();
+        __f_ = 0;
+        __f.__f_->__clone((__base*)&__buf_);
+        __f.__f_->destroy();
+        __f.__f_ = 0;
+        __f_ = (__base*)&__buf_;
+        __t->__clone((__base*)&__f.__buf_);
+        __t->destroy();
+        __f.__f_ = (__base*)&__f.__buf_;
+    }
+    else if (__f_ == (__base*)&__buf_)
+    {
+        __f_->__clone((__base*)&__f.__buf_);
+        __f_->destroy();
+        __f_ = __f.__f_;
+        __f.__f_ = (__base*)&__f.__buf_;
+    }
+    else if (__f.__f_ == (__base*)&__f.__buf_)
+    {
+        __f.__f_->__clone((__base*)&__buf_);
+        __f.__f_->destroy();
+        __f.__f_ = __f_;
+        __f_ = (__base*)&__buf_;
+    }
+    else
+        _VSTD::swap(__f_, __f.__f_);
+}
+
+template<class _Rp, class ..._ArgTypes>
+_Rp
+function<_Rp(_ArgTypes...)>::operator()(_ArgTypes... __arg) const
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__f_ == 0)
+        throw bad_function_call();
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return (*__f_)(_VSTD::forward<_ArgTypes>(__arg)...);
+}
+
+#ifndef _LIBCPP_NO_RTTI
+
+template<class _Rp, class ..._ArgTypes>
+const std::type_info&
+function<_Rp(_ArgTypes...)>::target_type() const _NOEXCEPT
+{
+    if (__f_ == 0)
+        return typeid(void);
+    return __f_->target_type();
+}
+
+template<class _Rp, class ..._ArgTypes>
+template <typename _Tp>
+_Tp*
+function<_Rp(_ArgTypes...)>::target() _NOEXCEPT
+{
+    if (__f_ == 0)
+        return (_Tp*)0;
+    return (_Tp*)__f_->target(typeid(_Tp));
+}
+
+template<class _Rp, class ..._ArgTypes>
+template <typename _Tp>
+const _Tp*
+function<_Rp(_ArgTypes...)>::target() const _NOEXCEPT
+{
+    if (__f_ == 0)
+        return (const _Tp*)0;
+    return (const _Tp*)__f_->target(typeid(_Tp));
+}
+
+#endif  // _LIBCPP_NO_RTTI
+
+template <class _Rp, class... _ArgTypes>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const function<_Rp(_ArgTypes...)>& __f, nullptr_t) _NOEXCEPT {return !__f;}
+
+template <class _Rp, class... _ArgTypes>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(nullptr_t, const function<_Rp(_ArgTypes...)>& __f) _NOEXCEPT {return !__f;}
+
+template <class _Rp, class... _ArgTypes>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const function<_Rp(_ArgTypes...)>& __f, nullptr_t) _NOEXCEPT {return (bool)__f;}
+
+template <class _Rp, class... _ArgTypes>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(nullptr_t, const function<_Rp(_ArgTypes...)>& __f) _NOEXCEPT {return (bool)__f;}
+
+template <class _Rp, class... _ArgTypes>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(function<_Rp(_ArgTypes...)>& __x, function<_Rp(_ArgTypes...)>& __y) _NOEXCEPT
+{return __x.swap(__y);}
+
+#else // _LIBCPP_HAS_NO_VARIADICS
+
+#include <__functional_03>
+
+#endif
+
+////////////////////////////////////////////////////////////////////////////////
+//                                  BIND
+//==============================================================================
+
+template<class _Tp> struct __is_bind_expression : public false_type {};
+template<class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_bind_expression
+    : public __is_bind_expression<typename remove_cv<_Tp>::type> {};
+
+template<class _Tp> struct __is_placeholder : public integral_constant<int, 0> {};
+template<class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_placeholder
+    : public __is_placeholder<typename remove_cv<_Tp>::type> {};
+
+namespace placeholders
+{
+
+template <int _Np> struct __ph {};
+
+_LIBCPP_FUNC_VIS extern __ph<1>   _1;
+_LIBCPP_FUNC_VIS extern __ph<2>   _2;
+_LIBCPP_FUNC_VIS extern __ph<3>   _3;
+_LIBCPP_FUNC_VIS extern __ph<4>   _4;
+_LIBCPP_FUNC_VIS extern __ph<5>   _5;
+_LIBCPP_FUNC_VIS extern __ph<6>   _6;
+_LIBCPP_FUNC_VIS extern __ph<7>   _7;
+_LIBCPP_FUNC_VIS extern __ph<8>   _8;
+_LIBCPP_FUNC_VIS extern __ph<9>   _9;
+_LIBCPP_FUNC_VIS extern __ph<10> _10;
+
+}  // placeholders
+
+template<int _Np>
+struct __is_placeholder<placeholders::__ph<_Np> >
+    : public integral_constant<int, _Np> {};
+
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Uj>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp&
+__mu(reference_wrapper<_Tp> __t, _Uj&)
+{
+    return __t.get();
+}
+
+template <class _Ti, class ..._Uj, size_t ..._Indx>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __invoke_of<_Ti&, _Uj...>::type
+__mu_expand(_Ti& __ti, tuple<_Uj...>& __uj, __tuple_indices<_Indx...>)
+{
+    return __ti(_VSTD::forward<_Uj>(_VSTD::get<_Indx>(__uj))...);
+}
+
+template <class _Ti, class ..._Uj>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __lazy_enable_if
+<
+    is_bind_expression<_Ti>::value,
+    __invoke_of<_Ti&, _Uj...>
+>::type
+__mu(_Ti& __ti, tuple<_Uj...>& __uj)
+{
+    typedef typename __make_tuple_indices<sizeof...(_Uj)>::type __indices;
+    return  __mu_expand(__ti, __uj, __indices());
+}
+
+template <bool IsPh, class _Ti, class _Uj>
+struct __mu_return2 {};
+
+template <class _Ti, class _Uj>
+struct __mu_return2<true, _Ti, _Uj>
+{
+    typedef typename tuple_element<is_placeholder<_Ti>::value - 1, _Uj>::type type;
+};
+
+template <class _Ti, class _Uj>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    0 < is_placeholder<_Ti>::value,
+    typename __mu_return2<0 < is_placeholder<_Ti>::value, _Ti, _Uj>::type
+>::type
+__mu(_Ti&, _Uj& __uj)
+{
+    const size_t _Indx = is_placeholder<_Ti>::value - 1;
+    return _VSTD::forward<typename tuple_element<_Indx, _Uj>::type>(_VSTD::get<_Indx>(__uj));
+}
+
+template <class _Ti, class _Uj>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_bind_expression<_Ti>::value &&
+    is_placeholder<_Ti>::value == 0 &&
+    !__is_reference_wrapper<_Ti>::value,
+    _Ti&
+>::type
+__mu(_Ti& __ti, _Uj&)
+{
+    return __ti;
+}
+
+template <class _Ti, bool IsReferenceWrapper, bool IsBindEx, bool IsPh,
+          class _TupleUj>
+struct ____mu_return;
+
+template <bool _Invokable, class _Ti, class ..._Uj>
+struct ____mu_return_invokable  // false
+{
+    typedef __nat type;
+};
+
+template <class _Ti, class ..._Uj>
+struct ____mu_return_invokable<true, _Ti, _Uj...>
+{
+    typedef typename __invoke_of<_Ti&, _Uj...>::type type;
+};
+
+template <class _Ti, class ..._Uj>
+struct ____mu_return<_Ti, false, true, false, tuple<_Uj...> >
+    : public ____mu_return_invokable<__invokable<_Ti&, _Uj...>::value, _Ti, _Uj...>
+{
+};
+
+template <class _Ti, class _TupleUj>
+struct ____mu_return<_Ti, false, false, true, _TupleUj>
+{
+    typedef typename tuple_element<is_placeholder<_Ti>::value - 1,
+                                   _TupleUj>::type&& type;
+};
+
+template <class _Ti, class _TupleUj>
+struct ____mu_return<_Ti, true, false, false, _TupleUj>
+{
+    typedef typename _Ti::type& type;
+};
+
+template <class _Ti, class _TupleUj>
+struct ____mu_return<_Ti, false, false, false, _TupleUj>
+{
+    typedef _Ti& type;
+};
+
+template <class _Ti, class _TupleUj>
+struct __mu_return
+    : public ____mu_return<_Ti,
+                           __is_reference_wrapper<_Ti>::value,
+                           is_bind_expression<_Ti>::value,
+                           0 < is_placeholder<_Ti>::value &&
+                           is_placeholder<_Ti>::value <= tuple_size<_TupleUj>::value,
+                           _TupleUj>
+{
+};
+
+template <class _Fp, class _BoundArgs, class _TupleUj>
+struct __is_valid_bind_return
+{
+    static const bool value = false;
+};
+
+template <class _Fp, class ..._BoundArgs, class _TupleUj>
+struct __is_valid_bind_return<_Fp, tuple<_BoundArgs...>, _TupleUj>
+{
+    static const bool value = __invokable<_Fp,
+                    typename __mu_return<_BoundArgs, _TupleUj>::type...>::value;
+};
+
+template <class _Fp, class ..._BoundArgs, class _TupleUj>
+struct __is_valid_bind_return<_Fp, const tuple<_BoundArgs...>, _TupleUj>
+{
+    static const bool value = __invokable<_Fp,
+                    typename __mu_return<const _BoundArgs, _TupleUj>::type...>::value;
+};
+
+template <class _Fp, class _BoundArgs, class _TupleUj,
+          bool = __is_valid_bind_return<_Fp, _BoundArgs, _TupleUj>::value>
+struct __bind_return;
+
+template <class _Fp, class ..._BoundArgs, class _TupleUj>
+struct __bind_return<_Fp, tuple<_BoundArgs...>, _TupleUj, true>
+{
+    typedef typename __invoke_of
+    <
+        _Fp&,
+        typename __mu_return
+        <
+            _BoundArgs,
+            _TupleUj
+        >::type...
+    >::type type;
+};
+
+template <class _Fp, class ..._BoundArgs, class _TupleUj>
+struct __bind_return<_Fp, const tuple<_BoundArgs...>, _TupleUj, true>
+{
+    typedef typename __invoke_of
+    <
+        _Fp&,
+        typename __mu_return
+        <
+            const _BoundArgs,
+            _TupleUj
+        >::type...
+    >::type type;
+};
+
+template <class _Fp, class _BoundArgs, size_t ..._Indx, class _Args>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __bind_return<_Fp, _BoundArgs, _Args>::type
+__apply_functor(_Fp& __f, _BoundArgs& __bound_args, __tuple_indices<_Indx...>,
+                _Args&& __args)
+{
+    return __invoke(__f, __mu(_VSTD::get<_Indx>(__bound_args), __args)...);
+}
+
+template<class _Fp, class ..._BoundArgs>
+class __bind
+    : public __weak_result_type<typename decay<_Fp>::type>
+{
+protected:
+    typedef typename decay<_Fp>::type _Fd;
+    typedef tuple<typename decay<_BoundArgs>::type...> _Td;
+private:
+    _Fd __f_;
+    _Td __bound_args_;
+
+    typedef typename __make_tuple_indices<sizeof...(_BoundArgs)>::type __indices;
+public:
+#ifdef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+
+    _LIBCPP_INLINE_VISIBILITY
+    __bind(const __bind& __b)
+        : __f_(__b.__f_),
+          __bound_args_(__b.__bound_args_) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __bind& operator=(const __bind& __b)
+    {
+        __f_ = __b.__f_;
+        __bound_args_ = __b.__bound_args_;
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __bind(__bind&& __b)
+        : __f_(_VSTD::move(__b.__f_)),
+          __bound_args_(_VSTD::move(__b.__bound_args_)) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __bind& operator=(__bind&& __b)
+    {
+        __f_ = _VSTD::move(__b.__f_);
+        __bound_args_ = _VSTD::move(__b.__bound_args_);
+        return *this;
+    }
+
+#endif  // _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+
+    template <class _Gp, class ..._BA,
+              class = typename enable_if
+                               <
+                                  is_constructible<_Fd, _Gp>::value &&
+                                  !is_same<typename remove_reference<_Gp>::type,
+                                           __bind>::value
+                               >::type>
+      _LIBCPP_INLINE_VISIBILITY
+      explicit __bind(_Gp&& __f, _BA&& ...__bound_args)
+        : __f_(_VSTD::forward<_Gp>(__f)),
+          __bound_args_(_VSTD::forward<_BA>(__bound_args)...) {}
+
+    template <class ..._Args>
+        _LIBCPP_INLINE_VISIBILITY
+        typename __bind_return<_Fd, _Td, tuple<_Args&&...> >::type
+        operator()(_Args&& ...__args)
+        {
+            return __apply_functor(__f_, __bound_args_, __indices(),
+                                  tuple<_Args&&...>(_VSTD::forward<_Args>(__args)...));
+        }
+
+    template <class ..._Args>
+        _LIBCPP_INLINE_VISIBILITY
+        typename __bind_return<const _Fd, const _Td, tuple<_Args&&...> >::type
+        operator()(_Args&& ...__args) const
+        {
+            return __apply_functor(__f_, __bound_args_, __indices(),
+                                   tuple<_Args&&...>(_VSTD::forward<_Args>(__args)...));
+        }
+};
+
+template<class _Fp, class ..._BoundArgs>
+struct __is_bind_expression<__bind<_Fp, _BoundArgs...> > : public true_type {};
+
+template<class _Rp, class _Fp, class ..._BoundArgs>
+class __bind_r
+    : public __bind<_Fp, _BoundArgs...>
+{
+    typedef __bind<_Fp, _BoundArgs...> base;
+    typedef typename base::_Fd _Fd;
+    typedef typename base::_Td _Td;
+public:
+    typedef _Rp result_type;
+
+#ifdef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+
+    _LIBCPP_INLINE_VISIBILITY
+    __bind_r(const __bind_r& __b)
+        : base(_VSTD::forward<const base&>(__b)) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __bind_r& operator=(const __bind_r& __b)
+    {
+        base::operator=(_VSTD::forward<const base&>(__b));
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __bind_r(__bind_r&& __b)
+        : base(_VSTD::forward<base>(__b)) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __bind_r& operator=(__bind_r&& __b)
+    {
+        base::operator=(_VSTD::forward<base>(__b));
+        return *this;
+    }
+
+#endif  // _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+
+    template <class _Gp, class ..._BA,
+              class = typename enable_if
+                               <
+                                  is_constructible<_Fd, _Gp>::value &&
+                                  !is_same<typename remove_reference<_Gp>::type,
+                                           __bind_r>::value
+                               >::type>
+      _LIBCPP_INLINE_VISIBILITY
+      explicit __bind_r(_Gp&& __f, _BA&& ...__bound_args)
+        : base(_VSTD::forward<_Gp>(__f),
+               _VSTD::forward<_BA>(__bound_args)...) {}
+
+    template <class ..._Args>
+        _LIBCPP_INLINE_VISIBILITY
+        typename enable_if
+        <
+            is_convertible<typename __bind_return<_Fd, _Td, tuple<_Args&&...> >::type,
+                           result_type>::value || is_void<_Rp>::value,
+            result_type
+        >::type
+        operator()(_Args&& ...__args)
+        {
+            typedef __invoke_void_return_wrapper<_Rp> _Invoker;
+            return _Invoker::__call(static_cast<base&>(*this), _VSTD::forward<_Args>(__args)...);
+        }
+
+    template <class ..._Args>
+        _LIBCPP_INLINE_VISIBILITY
+        typename enable_if
+        <
+            is_convertible<typename __bind_return<const _Fd, const _Td, tuple<_Args&&...> >::type,
+                           result_type>::value || is_void<_Rp>::value,
+            result_type
+        >::type
+        operator()(_Args&& ...__args) const
+        {
+            typedef __invoke_void_return_wrapper<_Rp> _Invoker;
+            return _Invoker::__call(static_cast<base const&>(*this), _VSTD::forward<_Args>(__args)...);
+        }
+};
+
+template<class _Rp, class _Fp, class ..._BoundArgs>
+struct __is_bind_expression<__bind_r<_Rp, _Fp, _BoundArgs...> > : public true_type {};
+
+template<class _Fp, class ..._BoundArgs>
+inline _LIBCPP_INLINE_VISIBILITY
+__bind<_Fp, _BoundArgs...>
+bind(_Fp&& __f, _BoundArgs&&... __bound_args)
+{
+    typedef __bind<_Fp, _BoundArgs...> type;
+    return type(_VSTD::forward<_Fp>(__f), _VSTD::forward<_BoundArgs>(__bound_args)...);
+}
+
+template<class _Rp, class _Fp, class ..._BoundArgs>
+inline _LIBCPP_INLINE_VISIBILITY
+__bind_r<_Rp, _Fp, _BoundArgs...>
+bind(_Fp&& __f, _BoundArgs&&... __bound_args)
+{
+    typedef __bind_r<_Rp, _Fp, _BoundArgs...> type;
+    return type(_VSTD::forward<_Fp>(__f), _VSTD::forward<_BoundArgs>(__bound_args)...);
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<bool>
+    : public unary_function<bool, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(bool __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
+};
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<char>
+    : public unary_function<char, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
+};
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<signed char>
+    : public unary_function<signed char, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(signed char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
+};
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<unsigned char>
+    : public unary_function<unsigned char, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(unsigned char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
+};
+
+#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<char16_t>
+    : public unary_function<char16_t, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(char16_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
+};
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<char32_t>
+    : public unary_function<char32_t, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(char32_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
+};
+
+#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<wchar_t>
+    : public unary_function<wchar_t, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(wchar_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
+};
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<short>
+    : public unary_function<short, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(short __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
+};
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<unsigned short>
+    : public unary_function<unsigned short, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(unsigned short __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
+};
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<int>
+    : public unary_function<int, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(int __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
+};
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<unsigned int>
+    : public unary_function<unsigned int, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(unsigned int __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
+};
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<long>
+    : public unary_function<long, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(long __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
+};
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<unsigned long>
+    : public unary_function<unsigned long, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(unsigned long __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
+};
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<long long>
+    : public __scalar_hash<long long>
+{
+};
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<unsigned long long>
+    : public __scalar_hash<unsigned long long>
+{
+};
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<float>
+    : public __scalar_hash<float>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(float __v) const _NOEXCEPT
+    {
+        // -0.0 and 0.0 should return same hash
+       if (__v == 0)
+           return 0;
+        return __scalar_hash<float>::operator()(__v);
+    }
+};
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<double>
+    : public __scalar_hash<double>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(double __v) const _NOEXCEPT
+    {
+        // -0.0 and 0.0 should return same hash
+       if (__v == 0)
+           return 0;
+        return __scalar_hash<double>::operator()(__v);
+    }
+};
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY hash<long double>
+    : public __scalar_hash<long double>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(long double __v) const _NOEXCEPT
+    {
+        // -0.0 and 0.0 should return same hash
+        if (__v == 0)
+            return 0;
+#if defined(__i386__)
+        // Zero out padding bits
+        union
+        {
+            long double __t;
+            struct
+            {
+                size_t __a;
+                size_t __b;
+                size_t __c;
+                size_t __d;
+            } __s;
+        } __u;
+        __u.__s.__a = 0;
+        __u.__s.__b = 0;
+        __u.__s.__c = 0;
+        __u.__s.__d = 0;
+        __u.__t = __v;
+        return __u.__s.__a ^ __u.__s.__b ^ __u.__s.__c ^ __u.__s.__d;
+#elif defined(__x86_64__)
+        // Zero out padding bits
+        union
+        {
+            long double __t;
+            struct
+            {
+                size_t __a;
+                size_t __b;
+            } __s;
+        } __u;
+        __u.__s.__a = 0;
+        __u.__s.__b = 0;
+        __u.__t = __v;
+        return __u.__s.__a ^ __u.__s.__b;
+#else
+        return __scalar_hash<long double>::operator()(__v);
+#endif
+    }
+};
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp>
+struct _LIBCPP_TYPE_VIS_ONLY hash
+    : public unary_function<_Tp, size_t>
+{
+    static_assert(is_enum<_Tp>::value, "This hash only works for enumeration types");
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(_Tp __v) const _NOEXCEPT
+    {
+        typedef typename underlying_type<_Tp>::type type;
+        return hash<type>{}(static_cast<type>(__v));
+    }
+};
+#endif
+
+
+#if _LIBCPP_STD_VER > 14
+template <class _Fn, class ..._Args>
+result_of_t<_Fn&&(_Args&&...)>
+invoke(_Fn&& __f, _Args&&... __args) {
+    return __invoke(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)...);
+}
+#endif
+
+// struct hash<T*> in <memory>
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_FUNCTIONAL

diff --git a/libcxx/include/future b/libcxx/include/future
new file mode 100644
index 0000000..5b5afe6
--- /dev/null
+++ b/libcxx/include/future

@@ -0,0 +1,2625 @@
+// -*- C++ -*-
+//===--------------------------- future -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_FUTURE
+#define _LIBCPP_FUTURE
+
+/*
+    future synopsis
+
+namespace std
+{
+
+enum class future_errc
+{
+    future_already_retrieved = 1,
+    promise_already_satisfied,
+    no_state,
+    broken_promise
+};
+
+enum class launch
+{
+    async = 1,
+    deferred = 2,
+    any = async | deferred
+};
+
+enum class future_status
+{
+    ready,
+    timeout,
+    deferred
+};
+
+template <> struct is_error_code_enum<future_errc> : public true_type { };
+error_code make_error_code(future_errc e) noexcept;
+error_condition make_error_condition(future_errc e) noexcept;
+
+const error_category& future_category() noexcept;
+
+class future_error
+    : public logic_error
+{
+public:
+    future_error(error_code ec);  // exposition only
+
+    const error_code& code() const noexcept;
+    const char*       what() const noexcept;
+};
+
+template <class R>
+class promise
+{
+public:
+    promise();
+    template <class Allocator>
+        promise(allocator_arg_t, const Allocator& a);
+    promise(promise&& rhs) noexcept;
+    promise(const promise& rhs) = delete;
+    ~promise();
+
+    // assignment
+    promise& operator=(promise&& rhs) noexcept;
+    promise& operator=(const promise& rhs) = delete;
+    void swap(promise& other) noexcept;
+
+    // retrieving the result
+    future<R> get_future();
+
+    // setting the result
+    void set_value(const R& r);
+    void set_value(R&& r);
+    void set_exception(exception_ptr p);
+
+    // setting the result with deferred notification
+    void set_value_at_thread_exit(const R& r);
+    void set_value_at_thread_exit(R&& r);
+    void set_exception_at_thread_exit(exception_ptr p);
+};
+
+template <class R>
+class promise<R&>
+{
+public:
+    promise();
+    template <class Allocator>
+        promise(allocator_arg_t, const Allocator& a);
+    promise(promise&& rhs) noexcept;
+    promise(const promise& rhs) = delete;
+    ~promise();
+
+    // assignment
+    promise& operator=(promise&& rhs) noexcept;
+    promise& operator=(const promise& rhs) = delete;
+    void swap(promise& other) noexcept;
+
+    // retrieving the result
+    future<R&> get_future();
+
+    // setting the result
+    void set_value(R& r);
+    void set_exception(exception_ptr p);
+
+    // setting the result with deferred notification
+    void set_value_at_thread_exit(R&);
+    void set_exception_at_thread_exit(exception_ptr p);
+};
+
+template <>
+class promise<void>
+{
+public:
+    promise();
+    template <class Allocator>
+        promise(allocator_arg_t, const Allocator& a);
+    promise(promise&& rhs) noexcept;
+    promise(const promise& rhs) = delete;
+    ~promise();
+
+    // assignment
+    promise& operator=(promise&& rhs) noexcept;
+    promise& operator=(const promise& rhs) = delete;
+    void swap(promise& other) noexcept;
+
+    // retrieving the result
+    future<void> get_future();
+
+    // setting the result
+    void set_value();
+    void set_exception(exception_ptr p);
+
+    // setting the result with deferred notification
+    void set_value_at_thread_exit();
+    void set_exception_at_thread_exit(exception_ptr p);
+};
+
+template <class R> void swap(promise<R>& x, promise<R>& y) noexcept;
+
+template <class R, class Alloc>
+    struct uses_allocator<promise<R>, Alloc> : public true_type {};
+
+template <class R>
+class future
+{
+public:
+    future() noexcept;
+    future(future&&) noexcept;
+    future(const future& rhs) = delete;
+    ~future();
+    future& operator=(const future& rhs) = delete;
+    future& operator=(future&&) noexcept;
+    shared_future<R> share();
+
+    // retrieving the value
+    R get();
+
+    // functions to check state
+    bool valid() const noexcept;
+
+    void wait() const;
+    template <class Rep, class Period>
+        future_status
+        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
+    template <class Clock, class Duration>
+        future_status
+        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
+};
+
+template <class R>
+class future<R&>
+{
+public:
+    future() noexcept;
+    future(future&&) noexcept;
+    future(const future& rhs) = delete;
+    ~future();
+    future& operator=(const future& rhs) = delete;
+    future& operator=(future&&) noexcept;
+    shared_future<R&> share();
+
+    // retrieving the value
+    R& get();
+
+    // functions to check state
+    bool valid() const noexcept;
+
+    void wait() const;
+    template <class Rep, class Period>
+        future_status
+        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
+    template <class Clock, class Duration>
+        future_status
+        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
+};
+
+template <>
+class future<void>
+{
+public:
+    future() noexcept;
+    future(future&&) noexcept;
+    future(const future& rhs) = delete;
+    ~future();
+    future& operator=(const future& rhs) = delete;
+    future& operator=(future&&) noexcept;
+    shared_future<void> share();
+
+    // retrieving the value
+    void get();
+
+    // functions to check state
+    bool valid() const noexcept;
+
+    void wait() const;
+    template <class Rep, class Period>
+        future_status
+        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
+    template <class Clock, class Duration>
+        future_status
+        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
+};
+
+template <class R>
+class shared_future
+{
+public:
+    shared_future() noexcept;
+    shared_future(const shared_future& rhs);
+    shared_future(future<R>&&) noexcept;
+    shared_future(shared_future&& rhs) noexcept;
+    ~shared_future();
+    shared_future& operator=(const shared_future& rhs);
+    shared_future& operator=(shared_future&& rhs) noexcept;
+
+    // retrieving the value
+    const R& get() const;
+
+    // functions to check state
+    bool valid() const noexcept;
+
+    void wait() const;
+    template <class Rep, class Period>
+        future_status
+        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
+    template <class Clock, class Duration>
+        future_status
+        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
+};
+
+template <class R>
+class shared_future<R&>
+{
+public:
+    shared_future() noexcept;
+    shared_future(const shared_future& rhs);
+    shared_future(future<R&>&&) noexcept;
+    shared_future(shared_future&& rhs) noexcept;
+    ~shared_future();
+    shared_future& operator=(const shared_future& rhs);
+    shared_future& operator=(shared_future&& rhs) noexcept;
+
+    // retrieving the value
+    R& get() const;
+
+    // functions to check state
+    bool valid() const noexcept;
+
+    void wait() const;
+    template <class Rep, class Period>
+        future_status
+        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
+    template <class Clock, class Duration>
+        future_status
+        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
+};
+
+template <>
+class shared_future<void>
+{
+public:
+    shared_future() noexcept;
+    shared_future(const shared_future& rhs);
+    shared_future(future<void>&&) noexcept;
+    shared_future(shared_future&& rhs) noexcept;
+    ~shared_future();
+    shared_future& operator=(const shared_future& rhs);
+    shared_future& operator=(shared_future&& rhs) noexcept;
+
+    // retrieving the value
+    void get() const;
+
+    // functions to check state
+    bool valid() const noexcept;
+
+    void wait() const;
+    template <class Rep, class Period>
+        future_status
+        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
+    template <class Clock, class Duration>
+        future_status
+        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
+};
+
+template <class F, class... Args>
+  future<typename result_of<typename decay<F>::type(typename decay<Args>::type...)>::type>
+  async(F&& f, Args&&... args);
+
+template <class F, class... Args>
+  future<typename result_of<typename decay<F>::type(typename decay<Args>::type...)>::type>
+  async(launch policy, F&& f, Args&&... args);
+
+template <class> class packaged_task; // undefined
+
+template <class R, class... ArgTypes>
+class packaged_task<R(ArgTypes...)>
+{
+public:
+    typedef R result_type;
+
+    // construction and destruction
+    packaged_task() noexcept;
+    template <class F>
+        explicit packaged_task(F&& f);
+    template <class F, class Allocator>
+        packaged_task(allocator_arg_t, const Allocator& a, F&& f);
+    ~packaged_task();
+
+    // no copy
+    packaged_task(const packaged_task&) = delete;
+    packaged_task& operator=(const packaged_task&) = delete;
+
+    // move support
+    packaged_task(packaged_task&& other) noexcept;
+    packaged_task& operator=(packaged_task&& other) noexcept;
+    void swap(packaged_task& other) noexcept;
+
+    bool valid() const noexcept;
+
+    // result retrieval
+    future<R> get_future();
+
+    // execution
+    void operator()(ArgTypes... );
+    void make_ready_at_thread_exit(ArgTypes...);
+
+    void reset();
+};
+
+template <class R>
+  void swap(packaged_task<R(ArgTypes...)&, packaged_task<R(ArgTypes...)>&) noexcept;
+
+template <class R, class Alloc> struct uses_allocator<packaged_task<R>, Alloc>;
+
+}  // std
+
+*/
+
+#include <__config>
+#include <system_error>
+#include <memory>
+#include <chrono>
+#include <exception>
+#include <mutex>
+#include <thread>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#ifdef _LIBCPP_HAS_NO_THREADS
+#error <future> is not supported on this single threaded system
+#else // !_LIBCPP_HAS_NO_THREADS
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+//enum class future_errc
+_LIBCPP_DECLARE_STRONG_ENUM(future_errc)
+{
+    future_already_retrieved = 1,
+    promise_already_satisfied,
+    no_state,
+    broken_promise
+};
+_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(future_errc)
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY is_error_code_enum<future_errc> : public true_type {};
+
+#ifdef _LIBCPP_HAS_NO_STRONG_ENUMS
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY is_error_code_enum<future_errc::__lx> : public true_type { };
+#endif
+
+//enum class launch
+_LIBCPP_DECLARE_STRONG_ENUM(launch)
+{
+    async = 1,
+    deferred = 2,
+    any = async | deferred
+};
+_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(launch)
+
+#ifndef _LIBCPP_HAS_NO_STRONG_ENUMS
+
+#ifdef _LIBCXX_UNDERLYING_TYPE
+typedef underlying_type<launch>::type __launch_underlying_type;
+#else
+typedef int __launch_underlying_type;
+#endif
+
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+launch
+operator&(launch __x, launch __y)
+{
+    return static_cast<launch>(static_cast<__launch_underlying_type>(__x) &
+                               static_cast<__launch_underlying_type>(__y));
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+launch
+operator|(launch __x, launch __y)
+{
+    return static_cast<launch>(static_cast<__launch_underlying_type>(__x) |
+                               static_cast<__launch_underlying_type>(__y));
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+launch
+operator^(launch __x, launch __y)
+{
+    return static_cast<launch>(static_cast<__launch_underlying_type>(__x) ^
+                               static_cast<__launch_underlying_type>(__y));
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+launch
+operator~(launch __x)
+{
+    return static_cast<launch>(~static_cast<__launch_underlying_type>(__x) & 3);
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+launch&
+operator&=(launch& __x, launch __y)
+{
+    __x = __x & __y; return __x;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+launch&
+operator|=(launch& __x, launch __y)
+{
+    __x = __x | __y; return __x;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+launch&
+operator^=(launch& __x, launch __y)
+{
+    __x = __x ^ __y; return __x;
+}
+
+#endif  // !_LIBCPP_HAS_NO_STRONG_ENUMS
+
+//enum class future_status
+_LIBCPP_DECLARE_STRONG_ENUM(future_status)
+{
+    ready,
+    timeout,
+    deferred
+};
+_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(future_status)
+
+_LIBCPP_FUNC_VIS
+const error_category& future_category() _NOEXCEPT;
+
+inline _LIBCPP_INLINE_VISIBILITY
+error_code
+make_error_code(future_errc __e) _NOEXCEPT
+{
+    return error_code(static_cast<int>(__e), future_category());
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+error_condition
+make_error_condition(future_errc __e) _NOEXCEPT
+{
+    return error_condition(static_cast<int>(__e), future_category());
+}
+
+class _LIBCPP_EXCEPTION_ABI future_error
+    : public logic_error
+{
+    error_code __ec_;
+public:
+    future_error(error_code __ec);
+
+    _LIBCPP_INLINE_VISIBILITY
+    const error_code& code() const _NOEXCEPT {return __ec_;}
+
+    virtual ~future_error() _NOEXCEPT;
+};
+
+class _LIBCPP_TYPE_VIS __assoc_sub_state
+    : public __shared_count
+{
+protected:
+    exception_ptr __exception_;
+    mutable mutex __mut_;
+    mutable condition_variable __cv_;
+    unsigned __state_;
+
+    virtual void __on_zero_shared() _NOEXCEPT;
+    void __sub_wait(unique_lock<mutex>& __lk);
+public:
+    enum
+    {
+        __constructed = 1,
+        __future_attached = 2,
+        ready = 4,
+        deferred = 8
+    };
+
+    _LIBCPP_INLINE_VISIBILITY
+    __assoc_sub_state() : __state_(0) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool __has_value() const
+        {return (__state_ & __constructed) || (__exception_ != nullptr);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __set_future_attached()
+    {
+        lock_guard<mutex> __lk(__mut_);
+        __state_ |= __future_attached;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    bool __has_future_attached() const {return (__state_ & __future_attached) != 0;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __set_deferred() {__state_ |= deferred;}
+
+    void __make_ready();
+    _LIBCPP_INLINE_VISIBILITY
+    bool __is_ready() const {return (__state_ & ready) != 0;}
+
+    void set_value();
+    void set_value_at_thread_exit();
+
+    void set_exception(exception_ptr __p);
+    void set_exception_at_thread_exit(exception_ptr __p);
+
+    void copy();
+
+    void wait();
+    template <class _Rep, class _Period>
+        future_status
+        wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const;
+    template <class _Clock, class _Duration>
+        future_status
+        wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const;
+
+    virtual void __execute();
+};
+
+template <class _Clock, class _Duration>
+future_status
+__assoc_sub_state::wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const
+{
+    unique_lock<mutex> __lk(__mut_);
+    if (__state_ & deferred)
+        return future_status::deferred;
+    while (!(__state_ & ready) && _Clock::now() < __abs_time)
+        __cv_.wait_until(__lk, __abs_time);
+    if (__state_ & ready)
+        return future_status::ready;
+    return future_status::timeout;
+}
+
+template <class _Rep, class _Period>
+inline _LIBCPP_INLINE_VISIBILITY
+future_status
+__assoc_sub_state::wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const
+{
+    return wait_until(chrono::steady_clock::now() + __rel_time);
+}
+
+template <class _Rp>
+class __assoc_state
+    : public __assoc_sub_state
+{
+    typedef __assoc_sub_state base;
+    typedef typename aligned_storage<sizeof(_Rp), alignment_of<_Rp>::value>::type _Up;
+protected:
+    _Up __value_;
+
+    virtual void __on_zero_shared() _NOEXCEPT;
+public:
+
+    template <class _Arg>
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+        void set_value(_Arg&& __arg);
+#else
+        void set_value(_Arg& __arg);
+#endif
+
+    template <class _Arg>
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+        void set_value_at_thread_exit(_Arg&& __arg);
+#else
+        void set_value_at_thread_exit(_Arg& __arg);
+#endif
+
+    _Rp move();
+    typename add_lvalue_reference<_Rp>::type copy();
+};
+
+template <class _Rp>
+void
+__assoc_state<_Rp>::__on_zero_shared() _NOEXCEPT
+{
+    if (this->__state_ & base::__constructed)
+        reinterpret_cast<_Rp*>(&__value_)->~_Rp();
+    delete this;
+}
+
+template <class _Rp>
+template <class _Arg>
+void
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+__assoc_state<_Rp>::set_value(_Arg&& __arg)
+#else
+__assoc_state<_Rp>::set_value(_Arg& __arg)
+#endif
+{
+    unique_lock<mutex> __lk(this->__mut_);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (this->__has_value())
+        throw future_error(make_error_code(future_errc::promise_already_satisfied));
+#endif
+    ::new(&__value_) _Rp(_VSTD::forward<_Arg>(__arg));
+    this->__state_ |= base::__constructed | base::ready;
+    __cv_.notify_all();
+}
+
+template <class _Rp>
+template <class _Arg>
+void
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+__assoc_state<_Rp>::set_value_at_thread_exit(_Arg&& __arg)
+#else
+__assoc_state<_Rp>::set_value_at_thread_exit(_Arg& __arg)
+#endif
+{
+    unique_lock<mutex> __lk(this->__mut_);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (this->__has_value())
+        throw future_error(make_error_code(future_errc::promise_already_satisfied));
+#endif
+    ::new(&__value_) _Rp(_VSTD::forward<_Arg>(__arg));
+    this->__state_ |= base::__constructed;
+    __thread_local_data()->__make_ready_at_thread_exit(this);
+}
+
+template <class _Rp>
+_Rp
+__assoc_state<_Rp>::move()
+{
+    unique_lock<mutex> __lk(this->__mut_);
+    this->__sub_wait(__lk);
+    if (this->__exception_ != nullptr)
+        rethrow_exception(this->__exception_);
+    return _VSTD::move(*reinterpret_cast<_Rp*>(&__value_));
+}
+
+template <class _Rp>
+typename add_lvalue_reference<_Rp>::type
+__assoc_state<_Rp>::copy()
+{
+    unique_lock<mutex> __lk(this->__mut_);
+    this->__sub_wait(__lk);
+    if (this->__exception_ != nullptr)
+        rethrow_exception(this->__exception_);
+    return *reinterpret_cast<_Rp*>(&__value_);
+}
+
+template <class _Rp>
+class __assoc_state<_Rp&>
+    : public __assoc_sub_state
+{
+    typedef __assoc_sub_state base;
+    typedef _Rp* _Up;
+protected:
+    _Up __value_;
+
+    virtual void __on_zero_shared() _NOEXCEPT;
+public:
+
+    void set_value(_Rp& __arg);
+    void set_value_at_thread_exit(_Rp& __arg);
+
+    _Rp& copy();
+};
+
+template <class _Rp>
+void
+__assoc_state<_Rp&>::__on_zero_shared() _NOEXCEPT
+{
+    delete this;
+}
+
+template <class _Rp>
+void
+__assoc_state<_Rp&>::set_value(_Rp& __arg)
+{
+    unique_lock<mutex> __lk(this->__mut_);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (this->__has_value())
+        throw future_error(make_error_code(future_errc::promise_already_satisfied));
+#endif
+    __value_ = _VSTD::addressof(__arg);
+    this->__state_ |= base::__constructed | base::ready;
+    __cv_.notify_all();
+}
+
+template <class _Rp>
+void
+__assoc_state<_Rp&>::set_value_at_thread_exit(_Rp& __arg)
+{
+    unique_lock<mutex> __lk(this->__mut_);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (this->__has_value())
+        throw future_error(make_error_code(future_errc::promise_already_satisfied));
+#endif
+    __value_ = _VSTD::addressof(__arg);
+    this->__state_ |= base::__constructed;
+    __thread_local_data()->__make_ready_at_thread_exit(this);
+}
+
+template <class _Rp>
+_Rp&
+__assoc_state<_Rp&>::copy()
+{
+    unique_lock<mutex> __lk(this->__mut_);
+    this->__sub_wait(__lk);
+    if (this->__exception_ != nullptr)
+        rethrow_exception(this->__exception_);
+    return *__value_;
+}
+
+template <class _Rp, class _Alloc>
+class __assoc_state_alloc
+    : public __assoc_state<_Rp>
+{
+    typedef __assoc_state<_Rp> base;
+    _Alloc __alloc_;
+
+    virtual void __on_zero_shared() _NOEXCEPT;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __assoc_state_alloc(const _Alloc& __a)
+        : __alloc_(__a) {}
+};
+
+template <class _Rp, class _Alloc>
+void
+__assoc_state_alloc<_Rp, _Alloc>::__on_zero_shared() _NOEXCEPT
+{
+    if (this->__state_ & base::__constructed)
+        reinterpret_cast<_Rp*>(_VSTD::addressof(this->__value_))->~_Rp();
+    typedef typename __allocator_traits_rebind<_Alloc, __assoc_state_alloc>::type _Al;
+    typedef allocator_traits<_Al> _ATraits;
+    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
+    _Al __a(__alloc_);
+    this->~__assoc_state_alloc();
+    __a.deallocate(_PTraits::pointer_to(*this), 1);
+}
+
+template <class _Rp, class _Alloc>
+class __assoc_state_alloc<_Rp&, _Alloc>
+    : public __assoc_state<_Rp&>
+{
+    typedef __assoc_state<_Rp&> base;
+    _Alloc __alloc_;
+
+    virtual void __on_zero_shared() _NOEXCEPT;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __assoc_state_alloc(const _Alloc& __a)
+        : __alloc_(__a) {}
+};
+
+template <class _Rp, class _Alloc>
+void
+__assoc_state_alloc<_Rp&, _Alloc>::__on_zero_shared() _NOEXCEPT
+{
+    typedef typename __allocator_traits_rebind<_Alloc, __assoc_state_alloc>::type _Al;
+    typedef allocator_traits<_Al> _ATraits;
+    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
+    _Al __a(__alloc_);
+    this->~__assoc_state_alloc();
+    __a.deallocate(_PTraits::pointer_to(*this), 1);
+}
+
+template <class _Alloc>
+class __assoc_sub_state_alloc
+    : public __assoc_sub_state
+{
+    typedef __assoc_sub_state base;
+    _Alloc __alloc_;
+
+    virtual void __on_zero_shared() _NOEXCEPT;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __assoc_sub_state_alloc(const _Alloc& __a)
+        : __alloc_(__a) {}
+};
+
+template <class _Alloc>
+void
+__assoc_sub_state_alloc<_Alloc>::__on_zero_shared() _NOEXCEPT
+{
+    typedef typename __allocator_traits_rebind<_Alloc, __assoc_sub_state_alloc>::type _Al;
+    typedef allocator_traits<_Al> _ATraits;
+    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
+    _Al __a(__alloc_);
+    this->~__assoc_sub_state_alloc();
+    __a.deallocate(_PTraits::pointer_to(*this), 1);
+}
+
+template <class _Rp, class _Fp>
+class __deferred_assoc_state
+    : public __assoc_state<_Rp>
+{
+    typedef __assoc_state<_Rp> base;
+
+    _Fp __func_;
+
+public:
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    explicit __deferred_assoc_state(_Fp&& __f);
+#endif
+
+    virtual void __execute();
+};
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Rp, class _Fp>
+inline _LIBCPP_INLINE_VISIBILITY
+__deferred_assoc_state<_Rp, _Fp>::__deferred_assoc_state(_Fp&& __f)
+    : __func_(_VSTD::forward<_Fp>(__f))
+{
+    this->__set_deferred();
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Rp, class _Fp>
+void
+__deferred_assoc_state<_Rp, _Fp>::__execute()
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        this->set_value(__func_());
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->set_exception(current_exception());
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+}
+
+template <class _Fp>
+class __deferred_assoc_state<void, _Fp>
+    : public __assoc_sub_state
+{
+    typedef __assoc_sub_state base;
+
+    _Fp __func_;
+
+public:
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    explicit __deferred_assoc_state(_Fp&& __f);
+#endif
+
+    virtual void __execute();
+};
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Fp>
+inline _LIBCPP_INLINE_VISIBILITY
+__deferred_assoc_state<void, _Fp>::__deferred_assoc_state(_Fp&& __f)
+    : __func_(_VSTD::forward<_Fp>(__f))
+{
+    this->__set_deferred();
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Fp>
+void
+__deferred_assoc_state<void, _Fp>::__execute()
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        __func_();
+        this->set_value();
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->set_exception(current_exception());
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+}
+
+template <class _Rp, class _Fp>
+class __async_assoc_state
+    : public __assoc_state<_Rp>
+{
+    typedef __assoc_state<_Rp> base;
+
+    _Fp __func_;
+
+    virtual void __on_zero_shared() _NOEXCEPT;
+public:
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    explicit __async_assoc_state(_Fp&& __f);
+#endif
+
+    virtual void __execute();
+};
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Rp, class _Fp>
+inline _LIBCPP_INLINE_VISIBILITY
+__async_assoc_state<_Rp, _Fp>::__async_assoc_state(_Fp&& __f)
+    : __func_(_VSTD::forward<_Fp>(__f))
+{
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Rp, class _Fp>
+void
+__async_assoc_state<_Rp, _Fp>::__execute()
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        this->set_value(__func_());
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->set_exception(current_exception());
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+}
+
+template <class _Rp, class _Fp>
+void
+__async_assoc_state<_Rp, _Fp>::__on_zero_shared() _NOEXCEPT
+{
+    this->wait();
+    base::__on_zero_shared();
+}
+
+template <class _Fp>
+class __async_assoc_state<void, _Fp>
+    : public __assoc_sub_state
+{
+    typedef __assoc_sub_state base;
+
+    _Fp __func_;
+
+    virtual void __on_zero_shared() _NOEXCEPT;
+public:
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    explicit __async_assoc_state(_Fp&& __f);
+#endif
+
+    virtual void __execute();
+};
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Fp>
+inline _LIBCPP_INLINE_VISIBILITY
+__async_assoc_state<void, _Fp>::__async_assoc_state(_Fp&& __f)
+    : __func_(_VSTD::forward<_Fp>(__f))
+{
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Fp>
+void
+__async_assoc_state<void, _Fp>::__execute()
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        __func_();
+        this->set_value();
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->set_exception(current_exception());
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+}
+
+template <class _Fp>
+void
+__async_assoc_state<void, _Fp>::__on_zero_shared() _NOEXCEPT
+{
+    this->wait();
+    base::__on_zero_shared();
+}
+
+template <class _Rp> class _LIBCPP_TYPE_VIS_ONLY promise;
+template <class _Rp> class _LIBCPP_TYPE_VIS_ONLY shared_future;
+
+// future
+
+template <class _Rp> class _LIBCPP_TYPE_VIS_ONLY future;
+
+template <class _Rp, class _Fp>
+future<_Rp>
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+__make_deferred_assoc_state(_Fp&& __f);
+#else
+__make_deferred_assoc_state(_Fp __f);
+#endif
+
+template <class _Rp, class _Fp>
+future<_Rp>
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+__make_async_assoc_state(_Fp&& __f);
+#else
+__make_async_assoc_state(_Fp __f);
+#endif
+
+template <class _Rp>
+class _LIBCPP_TYPE_VIS_ONLY future
+{
+    __assoc_state<_Rp>* __state_;
+
+    explicit future(__assoc_state<_Rp>* __state);
+
+    template <class> friend class promise;
+    template <class> friend class shared_future;
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template <class _R1, class _Fp>
+        friend future<_R1> __make_deferred_assoc_state(_Fp&& __f);
+    template <class _R1, class _Fp>
+        friend future<_R1> __make_async_assoc_state(_Fp&& __f);
+#else
+    template <class _R1, class _Fp>
+        friend future<_R1> __make_deferred_assoc_state(_Fp __f);
+    template <class _R1, class _Fp>
+        friend future<_R1> __make_async_assoc_state(_Fp __f);
+#endif
+
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    future() _NOEXCEPT : __state_(nullptr) {}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    future(future&& __rhs) _NOEXCEPT
+        : __state_(__rhs.__state_) {__rhs.__state_ = nullptr;}
+    future(const future&) = delete;
+    future& operator=(const future&) = delete;
+    _LIBCPP_INLINE_VISIBILITY
+    future& operator=(future&& __rhs) _NOEXCEPT
+        {
+            future(std::move(__rhs)).swap(*this);
+            return *this;
+        }
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+private:
+    future(const future&);
+    future& operator=(const future&);
+public:
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    ~future();
+    shared_future<_Rp> share();
+
+    // retrieving the value
+    _Rp get();
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(future& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
+
+    // functions to check state
+    _LIBCPP_INLINE_VISIBILITY
+    bool valid() const _NOEXCEPT {return __state_ != nullptr;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void wait() const {__state_->wait();}
+    template <class _Rep, class _Period>
+        _LIBCPP_INLINE_VISIBILITY
+        future_status
+        wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const
+            {return __state_->wait_for(__rel_time);}
+    template <class _Clock, class _Duration>
+        _LIBCPP_INLINE_VISIBILITY
+        future_status
+        wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const
+            {return __state_->wait_until(__abs_time);}
+};
+
+template <class _Rp>
+future<_Rp>::future(__assoc_state<_Rp>* __state)
+    : __state_(__state)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__state_->__has_future_attached())
+        throw future_error(make_error_code(future_errc::future_already_retrieved));
+#endif
+    __state_->__add_shared();
+    __state_->__set_future_attached();
+}
+
+struct __release_shared_count
+{
+    void operator()(__shared_count* p) {p->__release_shared();}
+};
+
+template <class _Rp>
+future<_Rp>::~future()
+{
+    if (__state_)
+        __state_->__release_shared();
+}
+
+template <class _Rp>
+_Rp
+future<_Rp>::get()
+{
+    unique_ptr<__shared_count, __release_shared_count> __(__state_);
+    __assoc_state<_Rp>* __s = __state_;
+    __state_ = nullptr;
+    return __s->move();
+}
+
+template <class _Rp>
+class _LIBCPP_TYPE_VIS_ONLY future<_Rp&>
+{
+    __assoc_state<_Rp&>* __state_;
+
+    explicit future(__assoc_state<_Rp&>* __state);
+
+    template <class> friend class promise;
+    template <class> friend class shared_future;
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template <class _R1, class _Fp>
+        friend future<_R1> __make_deferred_assoc_state(_Fp&& __f);
+    template <class _R1, class _Fp>
+        friend future<_R1> __make_async_assoc_state(_Fp&& __f);
+#else
+    template <class _R1, class _Fp>
+        friend future<_R1> __make_deferred_assoc_state(_Fp __f);
+    template <class _R1, class _Fp>
+        friend future<_R1> __make_async_assoc_state(_Fp __f);
+#endif
+
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    future() _NOEXCEPT : __state_(nullptr) {}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    future(future&& __rhs) _NOEXCEPT
+        : __state_(__rhs.__state_) {__rhs.__state_ = nullptr;}
+    future(const future&) = delete;
+    future& operator=(const future&) = delete;
+    _LIBCPP_INLINE_VISIBILITY
+    future& operator=(future&& __rhs) _NOEXCEPT
+        {
+            future(std::move(__rhs)).swap(*this);
+            return *this;
+        }
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+private:
+    future(const future&);
+    future& operator=(const future&);
+public:
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    ~future();
+    shared_future<_Rp&> share();
+
+    // retrieving the value
+    _Rp& get();
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(future& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
+
+    // functions to check state
+    _LIBCPP_INLINE_VISIBILITY
+    bool valid() const _NOEXCEPT {return __state_ != nullptr;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void wait() const {__state_->wait();}
+    template <class _Rep, class _Period>
+        _LIBCPP_INLINE_VISIBILITY
+        future_status
+        wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const
+            {return __state_->wait_for(__rel_time);}
+    template <class _Clock, class _Duration>
+        _LIBCPP_INLINE_VISIBILITY
+        future_status
+        wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const
+            {return __state_->wait_until(__abs_time);}
+};
+
+template <class _Rp>
+future<_Rp&>::future(__assoc_state<_Rp&>* __state)
+    : __state_(__state)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__state_->__has_future_attached())
+        throw future_error(make_error_code(future_errc::future_already_retrieved));
+#endif
+    __state_->__add_shared();
+    __state_->__set_future_attached();
+}
+
+template <class _Rp>
+future<_Rp&>::~future()
+{
+    if (__state_)
+        __state_->__release_shared();
+}
+
+template <class _Rp>
+_Rp&
+future<_Rp&>::get()
+{
+    unique_ptr<__shared_count, __release_shared_count> __(__state_);
+    __assoc_state<_Rp&>* __s = __state_;
+    __state_ = nullptr;
+    return __s->copy();
+}
+
+template <>
+class _LIBCPP_TYPE_VIS future<void>
+{
+    __assoc_sub_state* __state_;
+
+    explicit future(__assoc_sub_state* __state);
+
+    template <class> friend class promise;
+    template <class> friend class shared_future;
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template <class _R1, class _Fp>
+        friend future<_R1> __make_deferred_assoc_state(_Fp&& __f);
+    template <class _R1, class _Fp>
+        friend future<_R1> __make_async_assoc_state(_Fp&& __f);
+#else
+    template <class _R1, class _Fp>
+        friend future<_R1> __make_deferred_assoc_state(_Fp __f);
+    template <class _R1, class _Fp>
+        friend future<_R1> __make_async_assoc_state(_Fp __f);
+#endif
+
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    future() _NOEXCEPT : __state_(nullptr) {}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    future(future&& __rhs) _NOEXCEPT
+        : __state_(__rhs.__state_) {__rhs.__state_ = nullptr;}
+    future(const future&) = delete;
+    future& operator=(const future&) = delete;
+    _LIBCPP_INLINE_VISIBILITY
+    future& operator=(future&& __rhs) _NOEXCEPT
+        {
+            future(std::move(__rhs)).swap(*this);
+            return *this;
+        }
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+private:
+    future(const future&);
+    future& operator=(const future&);
+public:
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    ~future();
+    shared_future<void> share();
+
+    // retrieving the value
+    void get();
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(future& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
+
+    // functions to check state
+    _LIBCPP_INLINE_VISIBILITY
+    bool valid() const _NOEXCEPT {return __state_ != nullptr;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void wait() const {__state_->wait();}
+    template <class _Rep, class _Period>
+        _LIBCPP_INLINE_VISIBILITY
+        future_status
+        wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const
+            {return __state_->wait_for(__rel_time);}
+    template <class _Clock, class _Duration>
+        _LIBCPP_INLINE_VISIBILITY
+        future_status
+        wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const
+            {return __state_->wait_until(__abs_time);}
+};
+
+template <class _Rp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(future<_Rp>& __x, future<_Rp>& __y) _NOEXCEPT
+{
+    __x.swap(__y);
+}
+
+// promise<R>
+
+template <class _Callable> class packaged_task;
+
+template <class _Rp>
+class _LIBCPP_TYPE_VIS_ONLY promise
+{
+    __assoc_state<_Rp>* __state_;
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit promise(nullptr_t) _NOEXCEPT : __state_(nullptr) {}
+
+    template <class> friend class packaged_task;
+public:
+    promise();
+    template <class _Alloc>
+        promise(allocator_arg_t, const _Alloc& __a);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    promise(promise&& __rhs) _NOEXCEPT
+        : __state_(__rhs.__state_) {__rhs.__state_ = nullptr;}
+    promise(const promise& __rhs) = delete;
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+private:
+    promise(const promise& __rhs);
+public:
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    ~promise();
+
+    // assignment
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    promise& operator=(promise&& __rhs) _NOEXCEPT
+        {
+            promise(std::move(__rhs)).swap(*this);
+            return *this;
+        }
+    promise& operator=(const promise& __rhs) = delete;
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+private:
+    promise& operator=(const promise& __rhs);
+public:
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(promise& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
+
+    // retrieving the result
+    future<_Rp> get_future();
+
+    // setting the result
+    void set_value(const _Rp& __r);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    void set_value(_Rp&& __r);
+#endif
+    void set_exception(exception_ptr __p);
+
+    // setting the result with deferred notification
+    void set_value_at_thread_exit(const _Rp& __r);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    void set_value_at_thread_exit(_Rp&& __r);
+#endif
+    void set_exception_at_thread_exit(exception_ptr __p);
+};
+
+template <class _Rp>
+promise<_Rp>::promise()
+    : __state_(new __assoc_state<_Rp>)
+{
+}
+
+template <class _Rp>
+template <class _Alloc>
+promise<_Rp>::promise(allocator_arg_t, const _Alloc& __a0)
+{
+    typedef __assoc_state_alloc<_Rp, _Alloc> _State;
+    typedef typename __allocator_traits_rebind<_Alloc, _State>::type _A2;
+    typedef __allocator_destructor<_A2> _D2;
+    _A2 __a(__a0);
+    unique_ptr<_State, _D2> __hold(__a.allocate(1), _D2(__a, 1));
+    ::new(static_cast<void*>(_VSTD::addressof(*__hold.get()))) _State(__a0);
+    __state_ = _VSTD::addressof(*__hold.release());
+}
+
+template <class _Rp>
+promise<_Rp>::~promise()
+{
+    if (__state_)
+    {
+        if (!__state_->__has_value() && __state_->use_count() > 1)
+            __state_->set_exception(make_exception_ptr(
+                      future_error(make_error_code(future_errc::broken_promise))
+                                                      ));
+        __state_->__release_shared();
+    }
+}
+
+template <class _Rp>
+future<_Rp>
+promise<_Rp>::get_future()
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__state_ == nullptr)
+        throw future_error(make_error_code(future_errc::no_state));
+#endif
+    return future<_Rp>(__state_);
+}
+
+template <class _Rp>
+void
+promise<_Rp>::set_value(const _Rp& __r)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__state_ == nullptr)
+        throw future_error(make_error_code(future_errc::no_state));
+#endif
+    __state_->set_value(__r);
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Rp>
+void
+promise<_Rp>::set_value(_Rp&& __r)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__state_ == nullptr)
+        throw future_error(make_error_code(future_errc::no_state));
+#endif
+    __state_->set_value(_VSTD::move(__r));
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Rp>
+void
+promise<_Rp>::set_exception(exception_ptr __p)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__state_ == nullptr)
+        throw future_error(make_error_code(future_errc::no_state));
+#endif
+    __state_->set_exception(__p);
+}
+
+template <class _Rp>
+void
+promise<_Rp>::set_value_at_thread_exit(const _Rp& __r)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__state_ == nullptr)
+        throw future_error(make_error_code(future_errc::no_state));
+#endif
+    __state_->set_value_at_thread_exit(__r);
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Rp>
+void
+promise<_Rp>::set_value_at_thread_exit(_Rp&& __r)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__state_ == nullptr)
+        throw future_error(make_error_code(future_errc::no_state));
+#endif
+    __state_->set_value_at_thread_exit(_VSTD::move(__r));
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Rp>
+void
+promise<_Rp>::set_exception_at_thread_exit(exception_ptr __p)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__state_ == nullptr)
+        throw future_error(make_error_code(future_errc::no_state));
+#endif
+    __state_->set_exception_at_thread_exit(__p);
+}
+
+// promise<R&>
+
+template <class _Rp>
+class _LIBCPP_TYPE_VIS_ONLY promise<_Rp&>
+{
+    __assoc_state<_Rp&>* __state_;
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit promise(nullptr_t) _NOEXCEPT : __state_(nullptr) {}
+
+    template <class> friend class packaged_task;
+
+public:
+    promise();
+    template <class _Allocator>
+        promise(allocator_arg_t, const _Allocator& __a);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    promise(promise&& __rhs) _NOEXCEPT
+        : __state_(__rhs.__state_) {__rhs.__state_ = nullptr;}
+    promise(const promise& __rhs) = delete;
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+private:
+    promise(const promise& __rhs);
+public:
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    ~promise();
+
+    // assignment
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    promise& operator=(promise&& __rhs) _NOEXCEPT
+        {
+            promise(std::move(__rhs)).swap(*this);
+            return *this;
+        }
+    promise& operator=(const promise& __rhs) = delete;
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+private:
+    promise& operator=(const promise& __rhs);
+public:
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(promise& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
+
+    // retrieving the result
+    future<_Rp&> get_future();
+
+    // setting the result
+    void set_value(_Rp& __r);
+    void set_exception(exception_ptr __p);
+
+    // setting the result with deferred notification
+    void set_value_at_thread_exit(_Rp&);
+    void set_exception_at_thread_exit(exception_ptr __p);
+};
+
+template <class _Rp>
+promise<_Rp&>::promise()
+    : __state_(new __assoc_state<_Rp&>)
+{
+}
+
+template <class _Rp>
+template <class _Alloc>
+promise<_Rp&>::promise(allocator_arg_t, const _Alloc& __a0)
+{
+    typedef __assoc_state_alloc<_Rp&, _Alloc> _State;
+    typedef typename __allocator_traits_rebind<_Alloc, _State>::type _A2;
+    typedef __allocator_destructor<_A2> _D2;
+    _A2 __a(__a0);
+    unique_ptr<_State, _D2> __hold(__a.allocate(1), _D2(__a, 1));
+    ::new(static_cast<void*>(_VSTD::addressof(*__hold.get()))) _State(__a0);
+    __state_ = _VSTD::addressof(*__hold.release());
+}
+
+template <class _Rp>
+promise<_Rp&>::~promise()
+{
+    if (__state_)
+    {
+        if (!__state_->__has_value() && __state_->use_count() > 1)
+            __state_->set_exception(make_exception_ptr(
+                      future_error(make_error_code(future_errc::broken_promise))
+                                                      ));
+        __state_->__release_shared();
+    }
+}
+
+template <class _Rp>
+future<_Rp&>
+promise<_Rp&>::get_future()
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__state_ == nullptr)
+        throw future_error(make_error_code(future_errc::no_state));
+#endif
+    return future<_Rp&>(__state_);
+}
+
+template <class _Rp>
+void
+promise<_Rp&>::set_value(_Rp& __r)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__state_ == nullptr)
+        throw future_error(make_error_code(future_errc::no_state));
+#endif
+    __state_->set_value(__r);
+}
+
+template <class _Rp>
+void
+promise<_Rp&>::set_exception(exception_ptr __p)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__state_ == nullptr)
+        throw future_error(make_error_code(future_errc::no_state));
+#endif
+    __state_->set_exception(__p);
+}
+
+template <class _Rp>
+void
+promise<_Rp&>::set_value_at_thread_exit(_Rp& __r)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__state_ == nullptr)
+        throw future_error(make_error_code(future_errc::no_state));
+#endif
+    __state_->set_value_at_thread_exit(__r);
+}
+
+template <class _Rp>
+void
+promise<_Rp&>::set_exception_at_thread_exit(exception_ptr __p)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__state_ == nullptr)
+        throw future_error(make_error_code(future_errc::no_state));
+#endif
+    __state_->set_exception_at_thread_exit(__p);
+}
+
+// promise<void>
+
+template <>
+class _LIBCPP_TYPE_VIS promise<void>
+{
+    __assoc_sub_state* __state_;
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit promise(nullptr_t) _NOEXCEPT : __state_(nullptr) {}
+
+    template <class> friend class packaged_task;
+
+public:
+    promise();
+    template <class _Allocator>
+        promise(allocator_arg_t, const _Allocator& __a);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    promise(promise&& __rhs) _NOEXCEPT
+        : __state_(__rhs.__state_) {__rhs.__state_ = nullptr;}
+    promise(const promise& __rhs) = delete;
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+private:
+    promise(const promise& __rhs);
+public:
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    ~promise();
+
+    // assignment
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    promise& operator=(promise&& __rhs) _NOEXCEPT
+        {
+            promise(std::move(__rhs)).swap(*this);
+            return *this;
+        }
+    promise& operator=(const promise& __rhs) = delete;
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+private:
+    promise& operator=(const promise& __rhs);
+public:
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(promise& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
+
+    // retrieving the result
+    future<void> get_future();
+
+    // setting the result
+    void set_value();
+    void set_exception(exception_ptr __p);
+
+    // setting the result with deferred notification
+    void set_value_at_thread_exit();
+    void set_exception_at_thread_exit(exception_ptr __p);
+};
+
+template <class _Alloc>
+promise<void>::promise(allocator_arg_t, const _Alloc& __a0)
+{
+    typedef __assoc_sub_state_alloc<_Alloc> _State;
+    typedef typename __allocator_traits_rebind<_Alloc, _State>::type _A2;
+    typedef __allocator_destructor<_A2> _D2;
+    _A2 __a(__a0);
+    unique_ptr<_State, _D2> __hold(__a.allocate(1), _D2(__a, 1));
+    ::new(static_cast<void*>(_VSTD::addressof(*__hold.get()))) _State(__a0);
+    __state_ = _VSTD::addressof(*__hold.release());
+}
+
+template <class _Rp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(promise<_Rp>& __x, promise<_Rp>& __y) _NOEXCEPT
+{
+    __x.swap(__y);
+}
+
+template <class _Rp, class _Alloc>
+    struct _LIBCPP_TYPE_VIS_ONLY uses_allocator<promise<_Rp>, _Alloc>
+        : public true_type {};
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+// packaged_task
+
+template<class _Fp> class __packaged_task_base;
+
+template<class _Rp, class ..._ArgTypes>
+class __packaged_task_base<_Rp(_ArgTypes...)>
+{
+    __packaged_task_base(const __packaged_task_base&);
+    __packaged_task_base& operator=(const __packaged_task_base&);
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    __packaged_task_base() {}
+    _LIBCPP_INLINE_VISIBILITY
+    virtual ~__packaged_task_base() {}
+    virtual void __move_to(__packaged_task_base*) _NOEXCEPT = 0;
+    virtual void destroy() = 0;
+    virtual void destroy_deallocate() = 0;
+    virtual _Rp operator()(_ArgTypes&& ...) = 0;
+};
+
+template<class _FD, class _Alloc, class _FB> class __packaged_task_func;
+
+template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
+class __packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>
+    : public  __packaged_task_base<_Rp(_ArgTypes...)>
+{
+    __compressed_pair<_Fp, _Alloc> __f_;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __packaged_task_func(const _Fp& __f) : __f_(__f) {}
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __packaged_task_func(_Fp&& __f) : __f_(_VSTD::move(__f)) {}
+    _LIBCPP_INLINE_VISIBILITY
+    __packaged_task_func(const _Fp& __f, const _Alloc& __a)
+        : __f_(__f, __a) {}
+    _LIBCPP_INLINE_VISIBILITY
+    __packaged_task_func(_Fp&& __f, const _Alloc& __a)
+        : __f_(_VSTD::move(__f), __a) {}
+    virtual void __move_to(__packaged_task_base<_Rp(_ArgTypes...)>*) _NOEXCEPT;
+    virtual void destroy();
+    virtual void destroy_deallocate();
+    virtual _Rp operator()(_ArgTypes&& ... __args);
+};
+
+template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
+void
+__packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>::__move_to(
+                              __packaged_task_base<_Rp(_ArgTypes...)>* __p) _NOEXCEPT
+{
+    ::new (__p) __packaged_task_func(_VSTD::move(__f_.first()), _VSTD::move(__f_.second()));
+}
+
+template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
+void
+__packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>::destroy()
+{
+    __f_.~__compressed_pair<_Fp, _Alloc>();
+}
+
+template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
+void
+__packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>::destroy_deallocate()
+{
+    typedef typename __allocator_traits_rebind<_Alloc, __packaged_task_func>::type _Ap;
+    typedef allocator_traits<_Ap> _ATraits;
+    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
+    _Ap __a(__f_.second());
+    __f_.~__compressed_pair<_Fp, _Alloc>();
+    __a.deallocate(_PTraits::pointer_to(*this), 1);
+}
+
+template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
+_Rp
+__packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>::operator()(_ArgTypes&& ... __arg)
+{
+    return __invoke(__f_.first(), _VSTD::forward<_ArgTypes>(__arg)...);
+}
+
+template <class _Callable> class __packaged_task_function;
+
+template<class _Rp, class ..._ArgTypes>
+class __packaged_task_function<_Rp(_ArgTypes...)>
+{
+    typedef __packaged_task_base<_Rp(_ArgTypes...)> __base;
+    typename aligned_storage<3*sizeof(void*)>::type __buf_;
+    __base* __f_;
+
+public:
+    typedef _Rp result_type;
+
+    // construct/copy/destroy:
+    _LIBCPP_INLINE_VISIBILITY
+    __packaged_task_function() _NOEXCEPT : __f_(nullptr) {}
+    template<class _Fp>
+      __packaged_task_function(_Fp&& __f);
+    template<class _Fp, class _Alloc>
+      __packaged_task_function(allocator_arg_t, const _Alloc& __a, _Fp&& __f);
+
+    __packaged_task_function(__packaged_task_function&&) _NOEXCEPT;
+    __packaged_task_function& operator=(__packaged_task_function&&) _NOEXCEPT;
+
+    __packaged_task_function(const __packaged_task_function&) =  delete;
+    __packaged_task_function& operator=(const __packaged_task_function&) =  delete;
+
+    ~__packaged_task_function();
+
+    void swap(__packaged_task_function&) _NOEXCEPT;
+
+    _Rp operator()(_ArgTypes...) const;
+};
+
+template<class _Rp, class ..._ArgTypes>
+__packaged_task_function<_Rp(_ArgTypes...)>::__packaged_task_function(__packaged_task_function&& __f) _NOEXCEPT
+{
+    if (__f.__f_ == nullptr)
+        __f_ = nullptr;
+    else if (__f.__f_ == (__base*)&__f.__buf_)
+    {
+        __f_ = (__base*)&__buf_;
+        __f.__f_->__move_to(__f_);
+    }
+    else
+    {
+        __f_ = __f.__f_;
+        __f.__f_ = nullptr;
+    }
+}
+
+template<class _Rp, class ..._ArgTypes>
+template <class _Fp>
+__packaged_task_function<_Rp(_ArgTypes...)>::__packaged_task_function(_Fp&& __f)
+    : __f_(nullptr)
+{
+    typedef typename remove_reference<typename decay<_Fp>::type>::type _FR;
+    typedef __packaged_task_func<_FR, allocator<_FR>, _Rp(_ArgTypes...)> _FF;
+    if (sizeof(_FF) <= sizeof(__buf_))
+    {
+        __f_ = (__base*)&__buf_;
+        ::new (__f_) _FF(_VSTD::forward<_Fp>(__f));
+    }
+    else
+    {
+        typedef allocator<_FF> _Ap;
+        _Ap __a;
+        typedef __allocator_destructor<_Ap> _Dp;
+        unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+        ::new (__hold.get()) _FF(_VSTD::forward<_Fp>(__f), allocator<_FR>(__a));
+        __f_ = __hold.release();
+    }
+}
+
+template<class _Rp, class ..._ArgTypes>
+template <class _Fp, class _Alloc>
+__packaged_task_function<_Rp(_ArgTypes...)>::__packaged_task_function(
+                                  allocator_arg_t, const _Alloc& __a0, _Fp&& __f)
+    : __f_(nullptr)
+{
+    typedef typename remove_reference<typename decay<_Fp>::type>::type _FR;
+    typedef __packaged_task_func<_FR, _Alloc, _Rp(_ArgTypes...)> _FF;
+    if (sizeof(_FF) <= sizeof(__buf_))
+    {
+        __f_ = (__base*)&__buf_;
+        ::new (__f_) _FF(_VSTD::forward<_Fp>(__f));
+    }
+    else
+    {
+        typedef typename __allocator_traits_rebind<_Alloc, _FF>::type _Ap;
+        _Ap __a(__a0);
+        typedef __allocator_destructor<_Ap> _Dp;
+        unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
+        ::new (static_cast<void*>(_VSTD::addressof(*__hold.get())))
+            _FF(_VSTD::forward<_Fp>(__f), _Alloc(__a));
+        __f_ = _VSTD::addressof(*__hold.release());
+    }
+}
+
+template<class _Rp, class ..._ArgTypes>
+__packaged_task_function<_Rp(_ArgTypes...)>&
+__packaged_task_function<_Rp(_ArgTypes...)>::operator=(__packaged_task_function&& __f) _NOEXCEPT
+{
+    if (__f_ == (__base*)&__buf_)
+        __f_->destroy();
+    else if (__f_)
+        __f_->destroy_deallocate();
+    __f_ = nullptr;
+    if (__f.__f_ == nullptr)
+        __f_ = nullptr;
+    else if (__f.__f_ == (__base*)&__f.__buf_)
+    {
+        __f_ = (__base*)&__buf_;
+        __f.__f_->__move_to(__f_);
+    }
+    else
+    {
+        __f_ = __f.__f_;
+        __f.__f_ = nullptr;
+    }
+    return *this;
+}
+
+template<class _Rp, class ..._ArgTypes>
+__packaged_task_function<_Rp(_ArgTypes...)>::~__packaged_task_function()
+{
+    if (__f_ == (__base*)&__buf_)
+        __f_->destroy();
+    else if (__f_)
+        __f_->destroy_deallocate();
+}
+
+template<class _Rp, class ..._ArgTypes>
+void
+__packaged_task_function<_Rp(_ArgTypes...)>::swap(__packaged_task_function& __f) _NOEXCEPT
+{
+    if (__f_ == (__base*)&__buf_ && __f.__f_ == (__base*)&__f.__buf_)
+    {
+        typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
+        __base* __t = (__base*)&__tempbuf;
+        __f_->__move_to(__t);
+        __f_->destroy();
+        __f_ = nullptr;
+        __f.__f_->__move_to((__base*)&__buf_);
+        __f.__f_->destroy();
+        __f.__f_ = nullptr;
+        __f_ = (__base*)&__buf_;
+        __t->__move_to((__base*)&__f.__buf_);
+        __t->destroy();
+        __f.__f_ = (__base*)&__f.__buf_;
+    }
+    else if (__f_ == (__base*)&__buf_)
+    {
+        __f_->__move_to((__base*)&__f.__buf_);
+        __f_->destroy();
+        __f_ = __f.__f_;
+        __f.__f_ = (__base*)&__f.__buf_;
+    }
+    else if (__f.__f_ == (__base*)&__f.__buf_)
+    {
+        __f.__f_->__move_to((__base*)&__buf_);
+        __f.__f_->destroy();
+        __f.__f_ = __f_;
+        __f_ = (__base*)&__buf_;
+    }
+    else
+        _VSTD::swap(__f_, __f.__f_);
+}
+
+template<class _Rp, class ..._ArgTypes>
+inline _LIBCPP_INLINE_VISIBILITY
+_Rp
+__packaged_task_function<_Rp(_ArgTypes...)>::operator()(_ArgTypes... __arg) const
+{
+    return (*__f_)(_VSTD::forward<_ArgTypes>(__arg)...);
+}
+
+template<class _Rp, class ..._ArgTypes>
+class _LIBCPP_TYPE_VIS_ONLY packaged_task<_Rp(_ArgTypes...)>
+{
+public:
+    typedef _Rp result_type;
+
+private:
+    __packaged_task_function<result_type(_ArgTypes...)> __f_;
+    promise<result_type>                                __p_;
+
+public:
+    // construction and destruction
+    _LIBCPP_INLINE_VISIBILITY
+    packaged_task() _NOEXCEPT : __p_(nullptr) {}
+    template <class _Fp,
+              class = typename enable_if
+              <
+                  !is_same<
+                      typename decay<_Fp>::type, 
+                      packaged_task
+                      >::value
+                  >::type
+             >
+        _LIBCPP_INLINE_VISIBILITY
+        explicit packaged_task(_Fp&& __f) : __f_(_VSTD::forward<_Fp>(__f)) {}
+    template <class _Fp, class _Allocator,
+              class = typename enable_if
+              <
+                  !is_same<
+                      typename decay<_Fp>::type, 
+                      packaged_task
+                      >::value
+                  >::type
+              >
+        _LIBCPP_INLINE_VISIBILITY
+        packaged_task(allocator_arg_t, const _Allocator& __a, _Fp&& __f)
+             : __f_(allocator_arg, __a, _VSTD::forward<_Fp>(__f)),
+               __p_(allocator_arg, __a) {}
+    // ~packaged_task() = default;
+
+    // no copy
+    packaged_task(const packaged_task&) = delete;
+    packaged_task& operator=(const packaged_task&) = delete;
+
+    // move support
+    _LIBCPP_INLINE_VISIBILITY
+    packaged_task(packaged_task&& __other) _NOEXCEPT
+        : __f_(_VSTD::move(__other.__f_)), __p_(_VSTD::move(__other.__p_)) {}
+    _LIBCPP_INLINE_VISIBILITY
+    packaged_task& operator=(packaged_task&& __other) _NOEXCEPT
+    {
+        __f_ = _VSTD::move(__other.__f_);
+        __p_ = _VSTD::move(__other.__p_);
+        return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(packaged_task& __other) _NOEXCEPT
+    {
+        __f_.swap(__other.__f_);
+        __p_.swap(__other.__p_);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool valid() const _NOEXCEPT {return __p_.__state_ != nullptr;}
+
+    // result retrieval
+    _LIBCPP_INLINE_VISIBILITY
+    future<result_type> get_future() {return __p_.get_future();}
+
+    // execution
+    void operator()(_ArgTypes... __args);
+    void make_ready_at_thread_exit(_ArgTypes... __args);
+
+    void reset();
+};
+
+template<class _Rp, class ..._ArgTypes>
+void
+packaged_task<_Rp(_ArgTypes...)>::operator()(_ArgTypes... __args)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__p_.__state_ == nullptr)
+        throw future_error(make_error_code(future_errc::no_state));
+    if (__p_.__state_->__has_value())
+        throw future_error(make_error_code(future_errc::promise_already_satisfied));
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        __p_.set_value(__f_(_VSTD::forward<_ArgTypes>(__args)...));
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __p_.set_exception(current_exception());
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+}
+
+template<class _Rp, class ..._ArgTypes>
+void
+packaged_task<_Rp(_ArgTypes...)>::make_ready_at_thread_exit(_ArgTypes... __args)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__p_.__state_ == nullptr)
+        throw future_error(make_error_code(future_errc::no_state));
+    if (__p_.__state_->__has_value())
+        throw future_error(make_error_code(future_errc::promise_already_satisfied));
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        __p_.set_value_at_thread_exit(__f_(_VSTD::forward<_ArgTypes>(__args)...));
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __p_.set_exception_at_thread_exit(current_exception());
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+}
+
+template<class _Rp, class ..._ArgTypes>
+void
+packaged_task<_Rp(_ArgTypes...)>::reset()
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (!valid())
+        throw future_error(make_error_code(future_errc::no_state));
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    __p_ = promise<result_type>();
+}
+
+template<class ..._ArgTypes>
+class _LIBCPP_TYPE_VIS_ONLY packaged_task<void(_ArgTypes...)>
+{
+public:
+    typedef void result_type;
+
+private:
+    __packaged_task_function<result_type(_ArgTypes...)> __f_;
+    promise<result_type>                                __p_;
+
+public:
+    // construction and destruction
+    _LIBCPP_INLINE_VISIBILITY
+    packaged_task() _NOEXCEPT : __p_(nullptr) {}
+    template <class _Fp,
+              class = typename enable_if
+              <
+                  !is_same<
+                      typename decay<_Fp>::type, 
+                      packaged_task
+                      >::value
+                  >::type
+              >
+        _LIBCPP_INLINE_VISIBILITY
+        explicit packaged_task(_Fp&& __f) : __f_(_VSTD::forward<_Fp>(__f)) {}
+    template <class _Fp, class _Allocator,
+              class = typename enable_if
+              <
+                  !is_same<
+                      typename decay<_Fp>::type, 
+                      packaged_task
+                      >::value
+                  >::type
+              >    
+        _LIBCPP_INLINE_VISIBILITY
+        packaged_task(allocator_arg_t, const _Allocator& __a, _Fp&& __f)
+             : __f_(allocator_arg, __a, _VSTD::forward<_Fp>(__f)),
+               __p_(allocator_arg, __a) {}
+    // ~packaged_task() = default;
+
+    // no copy
+    packaged_task(const packaged_task&) = delete;
+    packaged_task& operator=(const packaged_task&) = delete;
+
+    // move support
+    _LIBCPP_INLINE_VISIBILITY
+    packaged_task(packaged_task&& __other) _NOEXCEPT
+        : __f_(_VSTD::move(__other.__f_)), __p_(_VSTD::move(__other.__p_)) {}
+    _LIBCPP_INLINE_VISIBILITY
+    packaged_task& operator=(packaged_task&& __other) _NOEXCEPT
+    {
+        __f_ = _VSTD::move(__other.__f_);
+        __p_ = _VSTD::move(__other.__p_);
+        return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(packaged_task& __other) _NOEXCEPT
+    {
+        __f_.swap(__other.__f_);
+        __p_.swap(__other.__p_);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool valid() const _NOEXCEPT {return __p_.__state_ != nullptr;}
+
+    // result retrieval
+    _LIBCPP_INLINE_VISIBILITY
+    future<result_type> get_future() {return __p_.get_future();}
+
+    // execution
+    void operator()(_ArgTypes... __args);
+    void make_ready_at_thread_exit(_ArgTypes... __args);
+
+    void reset();
+};
+
+template<class ..._ArgTypes>
+void
+packaged_task<void(_ArgTypes...)>::operator()(_ArgTypes... __args)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__p_.__state_ == nullptr)
+        throw future_error(make_error_code(future_errc::no_state));
+    if (__p_.__state_->__has_value())
+        throw future_error(make_error_code(future_errc::promise_already_satisfied));
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        __f_(_VSTD::forward<_ArgTypes>(__args)...);
+        __p_.set_value();
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __p_.set_exception(current_exception());
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+}
+
+template<class ..._ArgTypes>
+void
+packaged_task<void(_ArgTypes...)>::make_ready_at_thread_exit(_ArgTypes... __args)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__p_.__state_ == nullptr)
+        throw future_error(make_error_code(future_errc::no_state));
+    if (__p_.__state_->__has_value())
+        throw future_error(make_error_code(future_errc::promise_already_satisfied));
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        __f_(_VSTD::forward<_ArgTypes>(__args)...);
+        __p_.set_value_at_thread_exit();
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __p_.set_exception_at_thread_exit(current_exception());
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+}
+
+template<class ..._ArgTypes>
+void
+packaged_task<void(_ArgTypes...)>::reset()
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (!valid())
+        throw future_error(make_error_code(future_errc::no_state));
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    __p_ = promise<result_type>();
+}
+
+template <class _Callable>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(packaged_task<_Callable>& __x, packaged_task<_Callable>& __y) _NOEXCEPT
+{
+    __x.swap(__y);
+}
+
+template <class _Callable, class _Alloc>
+struct _LIBCPP_TYPE_VIS_ONLY uses_allocator<packaged_task<_Callable>, _Alloc>
+    : public true_type {};
+
+template <class _Rp, class _Fp>
+future<_Rp>
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+__make_deferred_assoc_state(_Fp&& __f)
+#else
+__make_deferred_assoc_state(_Fp __f)
+#endif
+{
+    unique_ptr<__deferred_assoc_state<_Rp, _Fp>, __release_shared_count>
+        __h(new __deferred_assoc_state<_Rp, _Fp>(_VSTD::forward<_Fp>(__f)));
+    return future<_Rp>(__h.get());
+}
+
+template <class _Rp, class _Fp>
+future<_Rp>
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+__make_async_assoc_state(_Fp&& __f)
+#else
+__make_async_assoc_state(_Fp __f)
+#endif
+{
+    unique_ptr<__async_assoc_state<_Rp, _Fp>, __release_shared_count>
+        __h(new __async_assoc_state<_Rp, _Fp>(_VSTD::forward<_Fp>(__f)));
+    _VSTD::thread(&__async_assoc_state<_Rp, _Fp>::__execute, __h.get()).detach();
+    return future<_Rp>(__h.get());
+}
+
+template <class _Fp, class... _Args>
+class __async_func
+{
+    tuple<_Fp, _Args...> __f_;
+
+public:
+    typedef typename __invoke_of<_Fp, _Args...>::type _Rp;
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __async_func(_Fp&& __f, _Args&&... __args)
+        : __f_(_VSTD::move(__f), _VSTD::move(__args)...) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __async_func(__async_func&& __f) : __f_(_VSTD::move(__f.__f_)) {}
+
+    _Rp operator()()
+    {
+        typedef typename __make_tuple_indices<1+sizeof...(_Args), 1>::type _Index;
+        return __execute(_Index());
+    }
+private:
+    template <size_t ..._Indices>
+    _Rp
+    __execute(__tuple_indices<_Indices...>)
+    {
+        return __invoke(_VSTD::move(_VSTD::get<0>(__f_)), _VSTD::move(_VSTD::get<_Indices>(__f_))...);
+    }
+};
+
+inline _LIBCPP_INLINE_VISIBILITY bool __does_policy_contain(launch __policy, launch __value )
+{ return (int(__policy) & int(__value)) != 0; }
+
+template <class _Fp, class... _Args>
+future<typename __invoke_of<typename decay<_Fp>::type, typename decay<_Args>::type...>::type>
+async(launch __policy, _Fp&& __f, _Args&&... __args)
+{
+    typedef __async_func<typename decay<_Fp>::type, typename decay<_Args>::type...> _BF;
+    typedef typename _BF::_Rp _Rp;
+
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif
+        if (__does_policy_contain(__policy, launch::async))
+        return _VSTD::__make_async_assoc_state<_Rp>(_BF(__decay_copy(_VSTD::forward<_Fp>(__f)),
+                                                     __decay_copy(_VSTD::forward<_Args>(__args))...));
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch ( ... ) { if (__policy == launch::async) throw ; }
+#endif
+
+    if (__does_policy_contain(__policy, launch::deferred))
+        return _VSTD::__make_deferred_assoc_state<_Rp>(_BF(__decay_copy(_VSTD::forward<_Fp>(__f)),
+                                                        __decay_copy(_VSTD::forward<_Args>(__args))...));
+    return future<_Rp>{};
+}
+
+template <class _Fp, class... _Args>
+inline _LIBCPP_INLINE_VISIBILITY
+future<typename __invoke_of<typename decay<_Fp>::type, typename decay<_Args>::type...>::type>
+async(_Fp&& __f, _Args&&... __args)
+{
+    return _VSTD::async(launch::any, _VSTD::forward<_Fp>(__f),
+                                    _VSTD::forward<_Args>(__args)...);
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+// shared_future
+
+template <class _Rp>
+class _LIBCPP_TYPE_VIS_ONLY shared_future
+{
+    __assoc_state<_Rp>* __state_;
+
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    shared_future() _NOEXCEPT : __state_(nullptr) {}
+    _LIBCPP_INLINE_VISIBILITY
+    shared_future(const shared_future& __rhs) : __state_(__rhs.__state_)
+        {if (__state_) __state_->__add_shared();}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    shared_future(future<_Rp>&& __f) _NOEXCEPT : __state_(__f.__state_)
+        {__f.__state_ = nullptr;}
+    _LIBCPP_INLINE_VISIBILITY
+    shared_future(shared_future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_)
+        {__rhs.__state_ = nullptr;}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    ~shared_future();
+    shared_future& operator=(const shared_future& __rhs);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    shared_future& operator=(shared_future&& __rhs) _NOEXCEPT
+        {
+            shared_future(std::move(__rhs)).swap(*this);
+            return *this;
+        }
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    // retrieving the value
+    _LIBCPP_INLINE_VISIBILITY
+    const _Rp& get() const {return __state_->copy();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(shared_future& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
+
+    // functions to check state
+    _LIBCPP_INLINE_VISIBILITY
+    bool valid() const _NOEXCEPT {return __state_ != nullptr;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void wait() const {__state_->wait();}
+    template <class _Rep, class _Period>
+        _LIBCPP_INLINE_VISIBILITY
+        future_status
+        wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const
+            {return __state_->wait_for(__rel_time);}
+    template <class _Clock, class _Duration>
+        _LIBCPP_INLINE_VISIBILITY
+        future_status
+        wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const
+            {return __state_->wait_until(__abs_time);}
+};
+
+template <class _Rp>
+shared_future<_Rp>::~shared_future()
+{
+    if (__state_)
+        __state_->__release_shared();
+}
+
+template <class _Rp>
+shared_future<_Rp>&
+shared_future<_Rp>::operator=(const shared_future& __rhs)
+{
+    if (__rhs.__state_)
+        __rhs.__state_->__add_shared();
+    if (__state_)
+        __state_->__release_shared();
+    __state_ = __rhs.__state_;
+    return *this;
+}
+
+template <class _Rp>
+class _LIBCPP_TYPE_VIS_ONLY shared_future<_Rp&>
+{
+    __assoc_state<_Rp&>* __state_;
+
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    shared_future() _NOEXCEPT : __state_(nullptr) {}
+    _LIBCPP_INLINE_VISIBILITY
+    shared_future(const shared_future& __rhs) : __state_(__rhs.__state_)
+        {if (__state_) __state_->__add_shared();}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    shared_future(future<_Rp&>&& __f) _NOEXCEPT : __state_(__f.__state_)
+        {__f.__state_ = nullptr;}
+    _LIBCPP_INLINE_VISIBILITY
+    shared_future(shared_future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_)
+        {__rhs.__state_ = nullptr;}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    ~shared_future();
+    shared_future& operator=(const shared_future& __rhs);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    shared_future& operator=(shared_future&& __rhs) _NOEXCEPT
+        {
+            shared_future(std::move(__rhs)).swap(*this);
+            return *this;
+        }
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    // retrieving the value
+    _LIBCPP_INLINE_VISIBILITY
+    _Rp& get() const {return __state_->copy();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(shared_future& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
+
+    // functions to check state
+    _LIBCPP_INLINE_VISIBILITY
+    bool valid() const _NOEXCEPT {return __state_ != nullptr;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void wait() const {__state_->wait();}
+    template <class _Rep, class _Period>
+        _LIBCPP_INLINE_VISIBILITY
+        future_status
+        wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const
+            {return __state_->wait_for(__rel_time);}
+    template <class _Clock, class _Duration>
+        _LIBCPP_INLINE_VISIBILITY
+        future_status
+        wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const
+            {return __state_->wait_until(__abs_time);}
+};
+
+template <class _Rp>
+shared_future<_Rp&>::~shared_future()
+{
+    if (__state_)
+        __state_->__release_shared();
+}
+
+template <class _Rp>
+shared_future<_Rp&>&
+shared_future<_Rp&>::operator=(const shared_future& __rhs)
+{
+    if (__rhs.__state_)
+        __rhs.__state_->__add_shared();
+    if (__state_)
+        __state_->__release_shared();
+    __state_ = __rhs.__state_;
+    return *this;
+}
+
+template <>
+class _LIBCPP_TYPE_VIS shared_future<void>
+{
+    __assoc_sub_state* __state_;
+
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    shared_future() _NOEXCEPT : __state_(nullptr) {}
+    _LIBCPP_INLINE_VISIBILITY
+    shared_future(const shared_future& __rhs) : __state_(__rhs.__state_)
+        {if (__state_) __state_->__add_shared();}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    shared_future(future<void>&& __f) _NOEXCEPT : __state_(__f.__state_)
+        {__f.__state_ = nullptr;}
+    _LIBCPP_INLINE_VISIBILITY
+    shared_future(shared_future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_)
+        {__rhs.__state_ = nullptr;}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    ~shared_future();
+    shared_future& operator=(const shared_future& __rhs);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    shared_future& operator=(shared_future&& __rhs) _NOEXCEPT
+        {
+            shared_future(std::move(__rhs)).swap(*this);
+            return *this;
+        }
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    // retrieving the value
+    _LIBCPP_INLINE_VISIBILITY
+    void get() const {__state_->copy();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(shared_future& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
+
+    // functions to check state
+    _LIBCPP_INLINE_VISIBILITY
+    bool valid() const _NOEXCEPT {return __state_ != nullptr;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void wait() const {__state_->wait();}
+    template <class _Rep, class _Period>
+        _LIBCPP_INLINE_VISIBILITY
+        future_status
+        wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const
+            {return __state_->wait_for(__rel_time);}
+    template <class _Clock, class _Duration>
+        _LIBCPP_INLINE_VISIBILITY
+        future_status
+        wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const
+            {return __state_->wait_until(__abs_time);}
+};
+
+template <class _Rp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(shared_future<_Rp>& __x, shared_future<_Rp>& __y) _NOEXCEPT
+{
+    __x.swap(__y);
+}
+
+template <class _Rp>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_future<_Rp>
+future<_Rp>::share()
+{
+    return shared_future<_Rp>(_VSTD::move(*this));
+}
+
+template <class _Rp>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_future<_Rp&>
+future<_Rp&>::share()
+{
+    return shared_future<_Rp&>(_VSTD::move(*this));
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+inline _LIBCPP_INLINE_VISIBILITY
+shared_future<void>
+future<void>::share()
+{
+    return shared_future<void>(_VSTD::move(*this));
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // !_LIBCPP_HAS_NO_THREADS
+
+#endif  // _LIBCPP_FUTURE

diff --git a/libcxx/include/initializer_list b/libcxx/include/initializer_list
new file mode 100644
index 0000000..663e49b
--- /dev/null
+++ b/libcxx/include/initializer_list

@@ -0,0 +1,118 @@
+// -*- C++ -*-
+//===----------------------- initializer_list -----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_INITIALIZER_LIST
+#define _LIBCPP_INITIALIZER_LIST
+
+/*
+    initializer_list synopsis
+
+namespace std
+{
+
+template<class E>
+class initializer_list
+{
+public:
+    typedef E        value_type;
+    typedef const E& reference;
+    typedef const E& const_reference;
+    typedef size_t   size_type;
+
+    typedef const E* iterator;
+    typedef const E* const_iterator;
+
+    initializer_list() noexcept; // constexpr in C++14
+
+    size_t   size()  const noexcept; // constexpr in C++14
+    const E* begin() const noexcept; // constexpr in C++14
+    const E* end()   const noexcept; // constexpr in C++14
+};
+
+template<class E> const E* begin(initializer_list<E> il) noexcept; // constexpr in C++14
+template<class E> const E* end(initializer_list<E> il) noexcept; // constexpr in C++14
+
+}  // std
+
+*/
+
+#include <__config>
+#include <cstddef>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+namespace std  // purposefully not versioned
+{
+
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+template<class _Ep>
+class _LIBCPP_TYPE_VIS_ONLY initializer_list
+{
+    const _Ep* __begin_;
+    size_t    __size_;
+
+    _LIBCPP_ALWAYS_INLINE
+    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    initializer_list(const _Ep* __b, size_t __s) _NOEXCEPT
+        : __begin_(__b),
+          __size_(__s)
+        {}
+public:
+    typedef _Ep        value_type;
+    typedef const _Ep& reference;
+    typedef const _Ep& const_reference;
+    typedef size_t    size_type;
+
+    typedef const _Ep* iterator;
+    typedef const _Ep* const_iterator;
+
+    _LIBCPP_ALWAYS_INLINE
+    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    initializer_list() _NOEXCEPT : __begin_(nullptr), __size_(0) {}
+
+    _LIBCPP_ALWAYS_INLINE
+    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    size_t    size()  const _NOEXCEPT {return __size_;}
+    
+    _LIBCPP_ALWAYS_INLINE
+    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    const _Ep* begin() const _NOEXCEPT {return __begin_;}
+
+    _LIBCPP_ALWAYS_INLINE
+    _LIBCPP_CONSTEXPR_AFTER_CXX11
+    const _Ep* end()   const _NOEXCEPT {return __begin_ + __size_;}
+};
+
+template<class _Ep>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_AFTER_CXX11
+const _Ep*
+begin(initializer_list<_Ep> __il) _NOEXCEPT
+{
+    return __il.begin();
+}
+
+template<class _Ep>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR_AFTER_CXX11
+const _Ep*
+end(initializer_list<_Ep> __il) _NOEXCEPT
+{
+    return __il.end();
+}
+
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+}  // std
+
+#endif  // _LIBCPP_INITIALIZER_LIST

diff --git a/libcxx/include/iomanip b/libcxx/include/iomanip
new file mode 100644
index 0000000..a5042c7
--- /dev/null
+++ b/libcxx/include/iomanip

@@ -0,0 +1,654 @@
+// -*- C++ -*-
+//===--------------------------- iomanip ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_IOMANIP
+#define _LIBCPP_IOMANIP
+
+/*
+    iomanip synopsis
+
+namespace std {
+
+// types T1, T2, ... are unspecified implementation types
+T1 resetiosflags(ios_base::fmtflags mask);
+T2 setiosflags (ios_base::fmtflags mask);
+T3 setbase(int base);
+template<charT> T4 setfill(charT c);
+T5 setprecision(int n);
+T6 setw(int n);
+template <class moneyT> T7 get_money(moneyT& mon, bool intl = false);
+template <class charT, class moneyT> T8 put_money(const moneyT& mon, bool intl = false);
+template <class charT> T9 get_time(struct tm* tmb, const charT* fmt);
+template <class charT> T10 put_time(const struct tm* tmb, const charT* fmt);
+
+template <class charT>
+  T11 quoted(const charT* s, charT delim=charT('"'), charT escape=charT('\\')); // C++14
+
+template <class charT, class traits, class Allocator>
+  T12 quoted(const basic_string<charT, traits, Allocator>& s,
+             charT delim=charT('"'), charT escape=charT('\\')); // C++14
+
+template <class charT, class traits, class Allocator>
+  T13 quoted(basic_string<charT, traits, Allocator>& s,
+             charT delim=charT('"'), charT escape=charT('\\')); // C++14
+
+}  // std
+
+*/
+
+#include <__config>
+#include <istream>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+// resetiosflags
+
+class __iom_t1
+{
+    ios_base::fmtflags __mask_;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __iom_t1(ios_base::fmtflags __m) : __mask_(__m) {}
+
+    template <class _CharT, class _Traits>
+    friend
+    _LIBCPP_INLINE_VISIBILITY
+    basic_istream<_CharT, _Traits>&
+    operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t1& __x)
+    {
+        __is.unsetf(__x.__mask_);
+        return __is;
+    }
+
+    template <class _CharT, class _Traits>
+    friend
+    _LIBCPP_INLINE_VISIBILITY
+    basic_ostream<_CharT, _Traits>&
+    operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t1& __x)
+    {
+        __os.unsetf(__x.__mask_);
+        return __os;
+    }
+};
+
+inline _LIBCPP_INLINE_VISIBILITY
+__iom_t1
+resetiosflags(ios_base::fmtflags __mask)
+{
+    return __iom_t1(__mask);
+}
+
+// setiosflags
+
+class __iom_t2
+{
+    ios_base::fmtflags __mask_;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __iom_t2(ios_base::fmtflags __m) : __mask_(__m) {}
+
+    template <class _CharT, class _Traits>
+    friend
+    _LIBCPP_INLINE_VISIBILITY
+    basic_istream<_CharT, _Traits>&
+    operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t2& __x)
+    {
+        __is.setf(__x.__mask_);
+        return __is;
+    }
+
+    template <class _CharT, class _Traits>
+    friend
+    _LIBCPP_INLINE_VISIBILITY
+    basic_ostream<_CharT, _Traits>&
+    operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t2& __x)
+    {
+        __os.setf(__x.__mask_);
+        return __os;
+    }
+};
+
+inline _LIBCPP_INLINE_VISIBILITY
+__iom_t2
+setiosflags(ios_base::fmtflags __mask)
+{
+    return __iom_t2(__mask);
+}
+
+// setbase
+
+class __iom_t3
+{
+    int __base_;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __iom_t3(int __b) : __base_(__b) {}
+
+    template <class _CharT, class _Traits>
+    friend
+    _LIBCPP_INLINE_VISIBILITY
+    basic_istream<_CharT, _Traits>&
+    operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t3& __x)
+    {
+        __is.setf(__x.__base_ == 8  ? ios_base::oct :
+                  __x.__base_ == 10 ? ios_base::dec :
+                  __x.__base_ == 16 ? ios_base::hex :
+                  ios_base::fmtflags(0), ios_base::basefield);
+        return __is;
+    }
+
+    template <class _CharT, class _Traits>
+    friend
+    _LIBCPP_INLINE_VISIBILITY
+    basic_ostream<_CharT, _Traits>&
+    operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t3& __x)
+    {
+        __os.setf(__x.__base_ == 8  ? ios_base::oct :
+                  __x.__base_ == 10 ? ios_base::dec :
+                  __x.__base_ == 16 ? ios_base::hex :
+                  ios_base::fmtflags(0), ios_base::basefield);
+        return __os;
+    }
+};
+
+inline _LIBCPP_INLINE_VISIBILITY
+__iom_t3
+setbase(int __base)
+{
+    return __iom_t3(__base);
+}
+
+// setfill
+
+template<class _CharT>
+class __iom_t4
+{
+    _CharT __fill_;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __iom_t4(_CharT __c) : __fill_(__c) {}
+
+    template <class _Traits>
+    friend
+    _LIBCPP_INLINE_VISIBILITY
+    basic_ostream<_CharT, _Traits>&
+    operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t4& __x)
+    {
+        __os.fill(__x.__fill_);
+        return __os;
+    }
+};
+
+template<class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+__iom_t4<_CharT>
+setfill(_CharT __c)
+{
+    return __iom_t4<_CharT>(__c);
+}
+
+// setprecision
+
+class __iom_t5
+{
+    int __n_;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __iom_t5(int __n) : __n_(__n) {}
+
+    template <class _CharT, class _Traits>
+    friend
+    _LIBCPP_INLINE_VISIBILITY
+    basic_istream<_CharT, _Traits>&
+    operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t5& __x)
+    {
+        __is.precision(__x.__n_);
+        return __is;
+    }
+
+    template <class _CharT, class _Traits>
+    friend
+    _LIBCPP_INLINE_VISIBILITY
+    basic_ostream<_CharT, _Traits>&
+    operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t5& __x)
+    {
+        __os.precision(__x.__n_);
+        return __os;
+    }
+};
+
+inline _LIBCPP_INLINE_VISIBILITY
+__iom_t5
+setprecision(int __n)
+{
+    return __iom_t5(__n);
+}
+
+// setw
+
+class __iom_t6
+{
+    int __n_;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __iom_t6(int __n) : __n_(__n) {}
+
+    template <class _CharT, class _Traits>
+    friend
+    _LIBCPP_INLINE_VISIBILITY
+    basic_istream<_CharT, _Traits>&
+    operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t6& __x)
+    {
+        __is.width(__x.__n_);
+        return __is;
+    }
+
+    template <class _CharT, class _Traits>
+    friend
+    _LIBCPP_INLINE_VISIBILITY
+    basic_ostream<_CharT, _Traits>&
+    operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t6& __x)
+    {
+        __os.width(__x.__n_);
+        return __os;
+    }
+};
+
+inline _LIBCPP_INLINE_VISIBILITY
+__iom_t6
+setw(int __n)
+{
+    return __iom_t6(__n);
+}
+
+// get_money
+
+template <class _MoneyT> class __iom_t7;
+
+template <class _CharT, class _Traits, class _MoneyT>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t7<_MoneyT>& __x);
+
+template <class _MoneyT>
+class __iom_t7
+{
+    _MoneyT& __mon_;
+    bool __intl_;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    __iom_t7(_MoneyT& __mon, bool __intl)
+        : __mon_(__mon), __intl_(__intl) {}
+
+    template <class _CharT, class _Traits, class _Mp>
+    friend
+    basic_istream<_CharT, _Traits>&
+    operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t7<_Mp>& __x);
+};
+
+template <class _CharT, class _Traits, class _MoneyT>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t7<_MoneyT>& __x)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typename basic_istream<_CharT, _Traits>::sentry __s(__is);
+        if (__s)
+        {
+            typedef istreambuf_iterator<_CharT, _Traits> _Ip;
+            typedef money_get<_CharT, _Ip> _Fp;
+            ios_base::iostate __err = ios_base::goodbit;
+            const _Fp& __mf = use_facet<_Fp>(__is.getloc());
+            __mf.get(_Ip(__is), _Ip(), __x.__intl_, __is, __err, __x.__mon_);
+            __is.setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __is.__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __is;
+}
+
+template <class _MoneyT>
+inline _LIBCPP_INLINE_VISIBILITY
+__iom_t7<_MoneyT>
+get_money(_MoneyT& __mon, bool __intl = false)
+{
+    return __iom_t7<_MoneyT>(__mon, __intl);
+}
+
+// put_money
+
+template <class _MoneyT> class __iom_t8;
+
+template <class _CharT, class _Traits, class _MoneyT>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t8<_MoneyT>& __x);
+
+template <class _MoneyT>
+class __iom_t8
+{
+    const _MoneyT& __mon_;
+    bool __intl_;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    __iom_t8(const _MoneyT& __mon, bool __intl)
+        : __mon_(__mon), __intl_(__intl) {}
+
+    template <class _CharT, class _Traits, class _Mp>
+    friend
+    basic_ostream<_CharT, _Traits>&
+    operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t8<_Mp>& __x);
+};
+
+template <class _CharT, class _Traits, class _MoneyT>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t8<_MoneyT>& __x)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typename basic_ostream<_CharT, _Traits>::sentry __s(__os);
+        if (__s)
+        {
+            typedef ostreambuf_iterator<_CharT, _Traits> _Op;
+            typedef money_put<_CharT, _Op> _Fp;
+            const _Fp& __mf = use_facet<_Fp>(__os.getloc());
+            if (__mf.put(_Op(__os), __x.__intl_, __os, __os.fill(), __x.__mon_).failed())
+                __os.setstate(ios_base::badbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __os.__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __os;
+}
+
+template <class _MoneyT>
+inline _LIBCPP_INLINE_VISIBILITY
+__iom_t8<_MoneyT>
+put_money(const _MoneyT& __mon, bool __intl = false)
+{
+    return __iom_t8<_MoneyT>(__mon, __intl);
+}
+
+// get_time
+
+template <class _CharT> class __iom_t9;
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t9<_CharT>& __x);
+
+template <class _CharT>
+class __iom_t9
+{
+    tm* __tm_;
+    const _CharT* __fmt_;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    __iom_t9(tm* __tm, const _CharT* __fmt)
+        : __tm_(__tm), __fmt_(__fmt) {}
+
+    template <class _Cp, class _Traits>
+    friend
+    basic_istream<_Cp, _Traits>&
+    operator>>(basic_istream<_Cp, _Traits>& __is, const __iom_t9<_Cp>& __x);
+};
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t9<_CharT>& __x)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typename basic_istream<_CharT, _Traits>::sentry __s(__is);
+        if (__s)
+        {
+            typedef istreambuf_iterator<_CharT, _Traits> _Ip;
+            typedef time_get<_CharT, _Ip> _Fp;
+            ios_base::iostate __err = ios_base::goodbit;
+            const _Fp& __tf = use_facet<_Fp>(__is.getloc());
+            __tf.get(_Ip(__is), _Ip(), __is, __err, __x.__tm_,
+                     __x.__fmt_, __x.__fmt_ + _Traits::length(__x.__fmt_));
+            __is.setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __is.__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __is;
+}
+
+template <class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+__iom_t9<_CharT>
+get_time(tm* __tm, const _CharT* __fmt)
+{
+    return __iom_t9<_CharT>(__tm, __fmt);
+}
+
+// put_time
+
+template <class _CharT> class __iom_t10;
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t10<_CharT>& __x);
+
+template <class _CharT>
+class __iom_t10
+{
+    const tm* __tm_;
+    const _CharT* __fmt_;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    __iom_t10(const tm* __tm, const _CharT* __fmt)
+        : __tm_(__tm), __fmt_(__fmt) {}
+
+    template <class _Cp, class _Traits>
+    friend
+    basic_ostream<_Cp, _Traits>&
+    operator<<(basic_ostream<_Cp, _Traits>& __os, const __iom_t10<_Cp>& __x);
+};
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t10<_CharT>& __x)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typename basic_ostream<_CharT, _Traits>::sentry __s(__os);
+        if (__s)
+        {
+            typedef ostreambuf_iterator<_CharT, _Traits> _Op;
+            typedef time_put<_CharT, _Op> _Fp;
+            const _Fp& __tf = use_facet<_Fp>(__os.getloc());
+            if (__tf.put(_Op(__os), __os, __os.fill(), __x.__tm_,
+                         __x.__fmt_, __x.__fmt_ + _Traits::length(__x.__fmt_)).failed())
+                __os.setstate(ios_base::badbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __os.__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __os;
+}
+
+template <class _CharT>
+inline _LIBCPP_INLINE_VISIBILITY
+__iom_t10<_CharT>
+put_time(const tm* __tm, const _CharT* __fmt)
+{
+    return __iom_t10<_CharT>(__tm, __fmt);
+}
+
+#if _LIBCPP_STD_VER > 11
+
+template <class _CharT, class _Traits, class _ForwardIterator>
+std::basic_ostream<_CharT, _Traits> &
+__quoted_output ( basic_ostream<_CharT, _Traits> &__os, 
+        _ForwardIterator __first, _ForwardIterator __last, _CharT __delim, _CharT __escape )
+{
+    _VSTD::basic_string<_CharT, _Traits> __str;
+    __str.push_back(__delim);
+    for ( ; __first != __last; ++ __first )
+    {
+        if (_Traits::eq (*__first, __escape) || _Traits::eq (*__first, __delim))
+            __str.push_back(__escape);
+        __str.push_back(*__first);
+    }
+    __str.push_back(__delim);
+    return __put_character_sequence(__os, __str.data(), __str.size());
+}
+
+template <class _CharT, class _Traits, class _String>
+basic_istream<_CharT, _Traits> &
+__quoted_input ( basic_istream<_CharT, _Traits> &__is, _String & __string, _CharT __delim, _CharT __escape )
+{
+    __string.clear ();
+    _CharT __c;
+    __is >> __c;
+    if ( __is.fail ())
+        return __is;
+
+    if (!_Traits::eq (__c, __delim))    // no delimiter, read the whole string
+    {
+        __is.unget ();
+        __is >> __string;
+        return __is;
+    }
+
+    __save_flags<_CharT, _Traits> sf(__is);
+    noskipws (__is);
+    while (true)
+        {
+        __is >> __c;
+        if ( __is.fail ())
+            break;
+        if (_Traits::eq (__c, __escape))
+        {
+            __is >> __c;
+            if ( __is.fail ())
+                break;
+        }
+        else if (_Traits::eq (__c, __delim))
+            break;
+        __string.push_back ( __c );
+        }
+    return __is;
+}
+
+
+template <class _CharT, class _Iter, class _Traits=char_traits<_CharT>>
+struct __quoted_output_proxy
+{
+    _Iter  __first;
+    _Iter  __last;
+    _CharT  __delim;
+    _CharT  __escape;
+
+    __quoted_output_proxy(_Iter __f, _Iter __l, _CharT __d, _CharT __e)
+    : __first(__f), __last(__l), __delim(__d), __escape(__e) {}
+    //  This would be a nice place for a string_ref 
+};
+
+template <class _CharT, class _Traits, class _Iter>
+basic_ostream<_CharT, _Traits>& operator<<(
+         basic_ostream<_CharT, _Traits>& __os, 
+         const __quoted_output_proxy<_CharT, _Iter, _Traits> & __proxy)
+{
+    return __quoted_output (__os, __proxy.__first, __proxy.__last, __proxy.__delim, __proxy.__escape);
+}
+
+template <class _CharT, class _Traits, class _Allocator>
+struct __quoted_proxy
+{
+    basic_string<_CharT, _Traits, _Allocator> &__string;
+    _CharT  __delim;
+    _CharT  __escape;
+
+    __quoted_proxy(basic_string<_CharT, _Traits, _Allocator> &__s, _CharT __d, _CharT __e)
+    : __string(__s), __delim(__d), __escape(__e) {}
+};
+
+template <class _CharT, class _Traits, class _Allocator>
+_LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>& operator<<(
+        basic_ostream<_CharT, _Traits>& __os, 
+        const __quoted_proxy<_CharT, _Traits, _Allocator> & __proxy)
+{
+    return __quoted_output (__os, __proxy.__string.cbegin (), __proxy.__string.cend (), __proxy.__delim, __proxy.__escape);
+}
+
+//  extractor for non-const basic_string& proxies
+template <class _CharT, class _Traits, class _Allocator>
+_LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>& operator>>(
+        basic_istream<_CharT, _Traits>& __is, 
+        const __quoted_proxy<_CharT, _Traits, _Allocator> & __proxy)
+{
+    return __quoted_input ( __is, __proxy.__string, __proxy.__delim, __proxy.__escape );
+}
+
+
+template <class _CharT>
+_LIBCPP_INLINE_VISIBILITY
+__quoted_output_proxy<_CharT, const _CharT *>
+quoted ( const _CharT *__s, _CharT __delim = _CharT('"'), _CharT __escape =_CharT('\\'))
+{
+    const _CharT *__end = __s;
+    while ( *__end ) ++__end;
+    return __quoted_output_proxy<_CharT, const _CharT *> ( __s, __end, __delim, __escape );
+}
+
+template <class _CharT, class _Traits, class _Allocator>
+_LIBCPP_INLINE_VISIBILITY
+__quoted_output_proxy<_CharT, typename basic_string <_CharT, _Traits, _Allocator>::const_iterator>
+quoted ( const basic_string <_CharT, _Traits, _Allocator> &__s, _CharT __delim = _CharT('"'), _CharT __escape=_CharT('\\'))
+{
+    return __quoted_output_proxy<_CharT, 
+            typename basic_string <_CharT, _Traits, _Allocator>::const_iterator> 
+                    ( __s.cbegin(), __s.cend (), __delim, __escape );
+}
+
+template <class _CharT, class _Traits, class _Allocator>
+__quoted_proxy<_CharT, _Traits, _Allocator>
+quoted ( basic_string <_CharT, _Traits, _Allocator> &__s, _CharT __delim = _CharT('"'), _CharT __escape=_CharT('\\'))
+{
+    return __quoted_proxy<_CharT, _Traits, _Allocator>( __s, __delim, __escape );
+}
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_IOMANIP

diff --git a/libcxx/include/ios b/libcxx/include/ios
new file mode 100644
index 0000000..ff79998
--- /dev/null
+++ b/libcxx/include/ios

@@ -0,0 +1,1023 @@
+// -*- C++ -*-
+//===---------------------------- ios -------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_IOS
+#define _LIBCPP_IOS
+
+/*
+    ios synopsis
+
+#include <iosfwd>
+
+namespace std
+{
+
+typedef OFF_T streamoff;
+typedef SZ_T streamsize;
+template <class stateT> class fpos;
+
+class ios_base
+{
+public:
+    class failure;
+
+    typedef T1 fmtflags;
+    static constexpr fmtflags boolalpha;
+    static constexpr fmtflags dec;
+    static constexpr fmtflags fixed;
+    static constexpr fmtflags hex;
+    static constexpr fmtflags internal;
+    static constexpr fmtflags left;
+    static constexpr fmtflags oct;
+    static constexpr fmtflags right;
+    static constexpr fmtflags scientific;
+    static constexpr fmtflags showbase;
+    static constexpr fmtflags showpoint;
+    static constexpr fmtflags showpos;
+    static constexpr fmtflags skipws;
+    static constexpr fmtflags unitbuf;
+    static constexpr fmtflags uppercase;
+    static constexpr fmtflags adjustfield;
+    static constexpr fmtflags basefield;
+    static constexpr fmtflags floatfield;
+
+    typedef T2 iostate;
+    static constexpr iostate badbit;
+    static constexpr iostate eofbit;
+    static constexpr iostate failbit;
+    static constexpr iostate goodbit;
+
+    typedef T3 openmode;
+    static constexpr openmode app;
+    static constexpr openmode ate;
+    static constexpr openmode binary;
+    static constexpr openmode in;
+    static constexpr openmode out;
+    static constexpr openmode trunc;
+
+    typedef T4 seekdir;
+    static constexpr seekdir beg;
+    static constexpr seekdir cur;
+    static constexpr seekdir end;
+
+    class Init;
+
+    // 27.5.2.2 fmtflags state:
+    fmtflags flags() const;
+    fmtflags flags(fmtflags fmtfl);
+    fmtflags setf(fmtflags fmtfl);
+    fmtflags setf(fmtflags fmtfl, fmtflags mask);
+    void unsetf(fmtflags mask);
+
+    streamsize precision() const;
+    streamsize precision(streamsize prec);
+    streamsize width() const;
+    streamsize width(streamsize wide);
+
+    // 27.5.2.3 locales:
+    locale imbue(const locale& loc);
+    locale getloc() const;
+
+    // 27.5.2.5 storage:
+    static int xalloc();
+    long& iword(int index);
+    void*& pword(int index);
+
+    // destructor
+    virtual ~ios_base();
+
+    // 27.5.2.6 callbacks;
+    enum event { erase_event, imbue_event, copyfmt_event };
+    typedef void (*event_callback)(event, ios_base&, int index);
+    void register_callback(event_callback fn, int index);
+
+    ios_base(const ios_base&) = delete;
+    ios_base& operator=(const ios_base&) = delete;
+
+    static bool sync_with_stdio(bool sync = true);
+
+protected:
+    ios_base();
+};
+
+template <class charT, class traits = char_traits<charT> >
+class basic_ios
+    : public ios_base
+{
+public:
+    // types:
+    typedef charT char_type;
+    typedef typename traits::int_type int_type;
+    typedef typename traits::pos_type pos_type;
+    typedef typename traits::off_type off_type;
+    typedef traits traits_type;
+
+    operator unspecified-bool-type() const;
+    bool operator!() const;
+    iostate rdstate() const;
+    void clear(iostate state = goodbit);
+    void setstate(iostate state);
+    bool good() const;
+    bool eof() const;
+    bool fail() const;
+    bool bad() const;
+
+    iostate exceptions() const;
+    void exceptions(iostate except);
+
+    // 27.5.4.1 Constructor/destructor:
+    explicit basic_ios(basic_streambuf<charT,traits>* sb);
+    virtual ~basic_ios();
+
+    // 27.5.4.2 Members:
+    basic_ostream<charT,traits>* tie() const;
+    basic_ostream<charT,traits>* tie(basic_ostream<charT,traits>* tiestr);
+
+    basic_streambuf<charT,traits>* rdbuf() const;
+    basic_streambuf<charT,traits>* rdbuf(basic_streambuf<charT,traits>* sb);
+
+    basic_ios& copyfmt(const basic_ios& rhs);
+
+    char_type fill() const;
+    char_type fill(char_type ch);
+
+    locale imbue(const locale& loc);
+
+    char narrow(char_type c, char dfault) const;
+    char_type widen(char c) const;
+
+    basic_ios(const basic_ios& ) = delete;
+    basic_ios& operator=(const basic_ios&) = delete;
+
+protected:
+    basic_ios();
+    void init(basic_streambuf<charT,traits>* sb);
+    void move(basic_ios& rhs);
+    void swap(basic_ios& rhs) noexcept;
+    void set_rdbuf(basic_streambuf<charT, traits>* sb);
+};
+
+// 27.5.5, manipulators:
+ios_base& boolalpha (ios_base& str);
+ios_base& noboolalpha(ios_base& str);
+ios_base& showbase (ios_base& str);
+ios_base& noshowbase (ios_base& str);
+ios_base& showpoint (ios_base& str);
+ios_base& noshowpoint(ios_base& str);
+ios_base& showpos (ios_base& str);
+ios_base& noshowpos (ios_base& str);
+ios_base& skipws (ios_base& str);
+ios_base& noskipws (ios_base& str);
+ios_base& uppercase (ios_base& str);
+ios_base& nouppercase(ios_base& str);
+ios_base& unitbuf (ios_base& str);
+ios_base& nounitbuf (ios_base& str);
+
+// 27.5.5.2 adjustfield:
+ios_base& internal (ios_base& str);
+ios_base& left (ios_base& str);
+ios_base& right (ios_base& str);
+
+// 27.5.5.3 basefield:
+ios_base& dec (ios_base& str);
+ios_base& hex (ios_base& str);
+ios_base& oct (ios_base& str);
+
+// 27.5.5.4 floatfield:
+ios_base& fixed (ios_base& str);
+ios_base& scientific (ios_base& str);
+ios_base& hexfloat (ios_base& str);
+ios_base& defaultfloat(ios_base& str);
+
+// 27.5.5.5 error reporting:
+enum class io_errc
+{
+    stream = 1
+};
+
+concept_map ErrorCodeEnum<io_errc> { };
+error_code make_error_code(io_errc e) noexcept; 
+error_condition make_error_condition(io_errc e) noexcept; 
+storage-class-specifier const error_category& iostream_category() noexcept;
+
+}  // std
+
+*/
+
+#include <__config>
+#include <iosfwd>
+#include <__locale>
+#include <system_error>
+
+#if __has_feature(cxx_atomic) && !defined(_LIBCPP_HAS_NO_THREADS)
+#include <atomic>     // for __xindex_
+#endif
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+typedef ptrdiff_t streamsize;
+
+class _LIBCPP_TYPE_VIS ios_base
+{
+public:
+    class _LIBCPP_TYPE_VIS failure;
+
+    typedef unsigned int fmtflags;
+    static const fmtflags boolalpha   = 0x0001;
+    static const fmtflags dec         = 0x0002;
+    static const fmtflags fixed       = 0x0004;
+    static const fmtflags hex         = 0x0008;
+    static const fmtflags internal    = 0x0010;
+    static const fmtflags left        = 0x0020;
+    static const fmtflags oct         = 0x0040;
+    static const fmtflags right       = 0x0080;
+    static const fmtflags scientific  = 0x0100;
+    static const fmtflags showbase    = 0x0200;
+    static const fmtflags showpoint   = 0x0400;
+    static const fmtflags showpos     = 0x0800;
+    static const fmtflags skipws      = 0x1000;
+    static const fmtflags unitbuf     = 0x2000;
+    static const fmtflags uppercase   = 0x4000;
+    static const fmtflags adjustfield = left | right | internal;
+    static const fmtflags basefield   = dec | oct | hex;
+    static const fmtflags floatfield  = scientific | fixed;
+
+    typedef unsigned int iostate;
+    typedef iostate      io_state;
+    static const iostate badbit  = 0x1;
+    static const iostate eofbit  = 0x2;
+    static const iostate failbit = 0x4;
+    static const iostate goodbit = 0x0;
+
+    typedef unsigned int openmode;
+    typedef openmode     open_mode;
+    static const openmode app    = 0x01;
+    static const openmode ate    = 0x02;
+    static const openmode binary = 0x04;
+    static const openmode in     = 0x08;
+    static const openmode out    = 0x10;
+    static const openmode trunc  = 0x20;
+
+    enum seekdir {beg, cur, end};
+    typedef seekdir seek_dir;
+
+    typedef _VSTD::streamoff streamoff;
+    typedef _VSTD::streampos streampos;
+
+    class _LIBCPP_TYPE_VIS Init;
+
+    // 27.5.2.2 fmtflags state:
+    _LIBCPP_INLINE_VISIBILITY fmtflags flags() const;
+    _LIBCPP_INLINE_VISIBILITY fmtflags flags(fmtflags __fmtfl);
+    _LIBCPP_INLINE_VISIBILITY fmtflags setf(fmtflags __fmtfl);
+    _LIBCPP_INLINE_VISIBILITY fmtflags setf(fmtflags __fmtfl, fmtflags __mask);
+    _LIBCPP_INLINE_VISIBILITY void unsetf(fmtflags __mask);
+
+    _LIBCPP_INLINE_VISIBILITY streamsize precision() const;
+    _LIBCPP_INLINE_VISIBILITY streamsize precision(streamsize __prec);
+    _LIBCPP_INLINE_VISIBILITY streamsize width() const;
+    _LIBCPP_INLINE_VISIBILITY streamsize width(streamsize __wide);
+
+    // 27.5.2.3 locales:
+    locale imbue(const locale& __loc);
+    locale getloc() const;
+
+    // 27.5.2.5 storage:
+    static int xalloc();
+    long& iword(int __index);
+    void*& pword(int __index);
+
+    // destructor
+    virtual ~ios_base();
+
+    // 27.5.2.6 callbacks;
+    enum event { erase_event, imbue_event, copyfmt_event };
+    typedef void (*event_callback)(event, ios_base&, int __index);
+    void register_callback(event_callback __fn, int __index);
+
+private:
+    ios_base(const ios_base&); // = delete;
+    ios_base& operator=(const ios_base&); // = delete;
+
+public:
+    static bool sync_with_stdio(bool __sync = true);
+
+    _LIBCPP_INLINE_VISIBILITY iostate rdstate() const;
+    void clear(iostate __state = goodbit);
+    _LIBCPP_INLINE_VISIBILITY void setstate(iostate __state);
+
+    _LIBCPP_INLINE_VISIBILITY bool good() const;
+    _LIBCPP_INLINE_VISIBILITY bool eof() const;
+    _LIBCPP_INLINE_VISIBILITY bool fail() const;
+    _LIBCPP_INLINE_VISIBILITY bool bad() const;
+
+    _LIBCPP_INLINE_VISIBILITY iostate exceptions() const;
+    _LIBCPP_INLINE_VISIBILITY void exceptions(iostate __iostate);
+
+    void __set_badbit_and_consider_rethrow();
+    void __set_failbit_and_consider_rethrow();
+
+protected:
+    _LIBCPP_INLINE_VISIBILITY
+    ios_base() {// purposefully does no initialization
+               }
+
+    void init(void* __sb);
+    _LIBCPP_ALWAYS_INLINE void* rdbuf() const {return __rdbuf_;}
+
+    _LIBCPP_ALWAYS_INLINE
+    void rdbuf(void* __sb)
+    {
+        __rdbuf_ = __sb;
+        clear();
+    }
+
+    void __call_callbacks(event);
+    void copyfmt(const ios_base&);
+    void move(ios_base&);
+    void swap(ios_base&) _NOEXCEPT;
+
+    _LIBCPP_ALWAYS_INLINE
+    void set_rdbuf(void* __sb)
+    {
+        __rdbuf_ = __sb;
+    }
+
+private:
+    // All data members must be scalars
+    fmtflags        __fmtflags_;
+    streamsize      __precision_;
+    streamsize      __width_;
+    iostate         __rdstate_;
+    iostate         __exceptions_;
+    void*           __rdbuf_;
+    void*           __loc_;
+    event_callback* __fn_;
+    int*            __index_;
+    size_t          __event_size_;
+    size_t          __event_cap_;
+#if __has_feature(cxx_atomic) && !defined(_LIBCPP_HAS_NO_THREADS)
+    static atomic<int> __xindex_;
+#else
+    static int      __xindex_;
+#endif
+    long*           __iarray_;
+    size_t          __iarray_size_;
+    size_t          __iarray_cap_;
+    void**          __parray_;
+    size_t          __parray_size_;
+    size_t          __parray_cap_;
+};
+
+//enum class io_errc
+_LIBCPP_DECLARE_STRONG_ENUM(io_errc)
+{
+    stream = 1
+};
+_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(io_errc)
+
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY is_error_code_enum<io_errc> : public true_type { };
+
+#ifdef _LIBCPP_HAS_NO_STRONG_ENUMS
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY is_error_code_enum<io_errc::__lx> : public true_type { };
+#endif
+
+_LIBCPP_FUNC_VIS
+const error_category& iostream_category() _NOEXCEPT;
+
+inline _LIBCPP_INLINE_VISIBILITY
+error_code
+make_error_code(io_errc __e) _NOEXCEPT
+{
+    return error_code(static_cast<int>(__e), iostream_category());
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+error_condition
+make_error_condition(io_errc __e) _NOEXCEPT
+{
+    return error_condition(static_cast<int>(__e), iostream_category());
+}
+
+class _LIBCPP_EXCEPTION_ABI ios_base::failure
+    : public system_error
+{
+public:
+    explicit failure(const string& __msg, const error_code& __ec = io_errc::stream);
+    explicit failure(const char* __msg, const error_code& __ec = io_errc::stream);
+    virtual ~failure() throw();
+};
+
+class _LIBCPP_TYPE_VIS ios_base::Init
+{
+public:
+    Init();
+    ~Init();
+};
+
+// fmtflags
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base::fmtflags
+ios_base::flags() const
+{
+    return __fmtflags_;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base::fmtflags
+ios_base::flags(fmtflags __fmtfl)
+{
+    fmtflags __r = __fmtflags_;
+    __fmtflags_ = __fmtfl;
+    return __r;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base::fmtflags
+ios_base::setf(fmtflags __fmtfl)
+{
+    fmtflags __r = __fmtflags_;
+    __fmtflags_ |= __fmtfl;
+    return __r;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+void
+ios_base::unsetf(fmtflags __mask)
+{
+    __fmtflags_ &= ~__mask;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base::fmtflags
+ios_base::setf(fmtflags __fmtfl, fmtflags __mask)
+{
+    fmtflags __r = __fmtflags_;
+    unsetf(__mask);
+    __fmtflags_ |= __fmtfl & __mask;
+    return __r;
+}
+
+// precision
+
+inline _LIBCPP_INLINE_VISIBILITY
+streamsize
+ios_base::precision() const
+{
+    return __precision_;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+streamsize
+ios_base::precision(streamsize __prec)
+{
+    streamsize __r = __precision_;
+    __precision_ = __prec;
+    return __r;
+}
+
+// width
+
+inline _LIBCPP_INLINE_VISIBILITY
+streamsize
+ios_base::width() const
+{
+    return __width_;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+streamsize
+ios_base::width(streamsize __wide)
+{
+    streamsize __r = __width_;
+    __width_ = __wide;
+    return __r;
+}
+
+// iostate
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base::iostate
+ios_base::rdstate() const
+{
+    return __rdstate_;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+void
+ios_base::setstate(iostate __state)
+{
+    clear(__rdstate_ | __state);
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+ios_base::good() const
+{
+    return __rdstate_ == 0;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+ios_base::eof() const
+{
+    return (__rdstate_ & eofbit) != 0;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+ios_base::fail() const
+{
+    return (__rdstate_ & (failbit | badbit)) != 0;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+ios_base::bad() const
+{
+    return (__rdstate_ & badbit) != 0;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base::iostate
+ios_base::exceptions() const
+{
+    return __exceptions_;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+void
+ios_base::exceptions(iostate __iostate)
+{
+    __exceptions_ = __iostate;
+    clear(__rdstate_);
+}
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TYPE_VIS_ONLY basic_ios
+    : public ios_base
+{
+public:
+    // types:
+    typedef _CharT char_type;
+    typedef _Traits traits_type;
+
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    _LIBCPP_ALWAYS_INLINE
+        _LIBCPP_EXPLICIT
+        operator bool() const {return !fail();}
+    _LIBCPP_ALWAYS_INLINE bool operator!() const    {return  fail();}
+    _LIBCPP_ALWAYS_INLINE iostate rdstate() const   {return ios_base::rdstate();}
+    _LIBCPP_ALWAYS_INLINE void clear(iostate __state = goodbit) {ios_base::clear(__state);}
+    _LIBCPP_ALWAYS_INLINE void setstate(iostate __state) {ios_base::setstate(__state);}
+    _LIBCPP_ALWAYS_INLINE bool good() const {return ios_base::good();}
+    _LIBCPP_ALWAYS_INLINE bool eof() const  {return ios_base::eof();}
+    _LIBCPP_ALWAYS_INLINE bool fail() const {return ios_base::fail();}
+    _LIBCPP_ALWAYS_INLINE bool bad() const  {return ios_base::bad();}
+
+    _LIBCPP_ALWAYS_INLINE iostate exceptions() const {return ios_base::exceptions();}
+    _LIBCPP_ALWAYS_INLINE void exceptions(iostate __iostate) {ios_base::exceptions(__iostate);}
+
+    // 27.5.4.1 Constructor/destructor:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit basic_ios(basic_streambuf<char_type,traits_type>* __sb);
+    virtual ~basic_ios();
+
+    // 27.5.4.2 Members:
+    _LIBCPP_INLINE_VISIBILITY 
+    basic_ostream<char_type, traits_type>* tie() const;
+    _LIBCPP_INLINE_VISIBILITY 
+    basic_ostream<char_type, traits_type>* tie(basic_ostream<char_type, traits_type>* __tiestr);
+
+    _LIBCPP_INLINE_VISIBILITY 
+    basic_streambuf<char_type, traits_type>* rdbuf() const;
+    _LIBCPP_INLINE_VISIBILITY 
+    basic_streambuf<char_type, traits_type>* rdbuf(basic_streambuf<char_type, traits_type>* __sb);
+
+    basic_ios& copyfmt(const basic_ios& __rhs);
+
+    _LIBCPP_INLINE_VISIBILITY 
+    char_type fill() const;
+    _LIBCPP_INLINE_VISIBILITY 
+    char_type fill(char_type __ch);
+
+    _LIBCPP_INLINE_VISIBILITY 
+    locale imbue(const locale& __loc);
+
+    _LIBCPP_INLINE_VISIBILITY 
+    char narrow(char_type __c, char __dfault) const;
+    _LIBCPP_INLINE_VISIBILITY 
+    char_type widen(char __c) const;
+
+protected:
+    _LIBCPP_ALWAYS_INLINE
+    basic_ios() {// purposefully does no initialization
+                }
+    _LIBCPP_INLINE_VISIBILITY 
+    void init(basic_streambuf<char_type, traits_type>* __sb);
+
+    _LIBCPP_INLINE_VISIBILITY 
+    void move(basic_ios& __rhs);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_ALWAYS_INLINE
+    void move(basic_ios&& __rhs) {move(__rhs);}
+#endif
+    _LIBCPP_INLINE_VISIBILITY 
+    void swap(basic_ios& __rhs) _NOEXCEPT;
+    _LIBCPP_INLINE_VISIBILITY 
+    void set_rdbuf(basic_streambuf<char_type, traits_type>* __sb);
+private:
+    basic_ostream<char_type, traits_type>* __tie_;
+     mutable int_type __fill_;
+};
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ios<_CharT, _Traits>::basic_ios(basic_streambuf<char_type,traits_type>* __sb)
+{
+    init(__sb);
+}
+
+template <class _CharT, class _Traits>
+basic_ios<_CharT, _Traits>::~basic_ios()
+{
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+basic_ios<_CharT, _Traits>::init(basic_streambuf<char_type, traits_type>* __sb)
+{
+    ios_base::init(__sb);
+    __tie_ = 0;
+    __fill_ = traits_type::eof();
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>*
+basic_ios<_CharT, _Traits>::tie() const
+{
+    return __tie_;
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>*
+basic_ios<_CharT, _Traits>::tie(basic_ostream<char_type, traits_type>* __tiestr)
+{
+    basic_ostream<char_type, traits_type>* __r = __tie_;
+    __tie_ = __tiestr;
+    return __r;
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_streambuf<_CharT, _Traits>*
+basic_ios<_CharT, _Traits>::rdbuf() const
+{
+    return static_cast<basic_streambuf<char_type, traits_type>*>(ios_base::rdbuf());
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_streambuf<_CharT, _Traits>*
+basic_ios<_CharT, _Traits>::rdbuf(basic_streambuf<char_type, traits_type>* __sb)
+{
+    basic_streambuf<char_type, traits_type>* __r = rdbuf();
+    ios_base::rdbuf(__sb);
+    return __r;
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+locale
+basic_ios<_CharT, _Traits>::imbue(const locale& __loc)
+{
+    locale __r = getloc();
+    ios_base::imbue(__loc);
+    if (rdbuf())
+        rdbuf()->pubimbue(__loc);
+    return __r;
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+char
+basic_ios<_CharT, _Traits>::narrow(char_type __c, char __dfault) const
+{
+    return use_facet<ctype<char_type> >(getloc()).narrow(__c, __dfault);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+_CharT
+basic_ios<_CharT, _Traits>::widen(char __c) const
+{
+    return use_facet<ctype<char_type> >(getloc()).widen(__c);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+_CharT
+basic_ios<_CharT, _Traits>::fill() const
+{
+    if (traits_type::eq_int_type(traits_type::eof(), __fill_))
+        __fill_ = widen(' ');
+    return __fill_;
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+_CharT
+basic_ios<_CharT, _Traits>::fill(char_type __ch)
+{
+    char_type __r = __fill_;
+    __fill_ = __ch;
+    return __r;
+}
+
+template <class _CharT, class _Traits>
+basic_ios<_CharT, _Traits>&
+basic_ios<_CharT, _Traits>::copyfmt(const basic_ios& __rhs)
+{
+    if (this != &__rhs)
+    {
+        __call_callbacks(erase_event);
+        ios_base::copyfmt(__rhs);
+        __tie_ = __rhs.__tie_;
+        __fill_ = __rhs.__fill_;
+        __call_callbacks(copyfmt_event);
+        exceptions(__rhs.exceptions());
+    }
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+basic_ios<_CharT, _Traits>::move(basic_ios& __rhs)
+{
+    ios_base::move(__rhs);
+    __tie_ = __rhs.__tie_;
+    __rhs.__tie_ = 0;
+    __fill_ = __rhs.__fill_;
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+basic_ios<_CharT, _Traits>::swap(basic_ios& __rhs) _NOEXCEPT
+{
+    ios_base::swap(__rhs);
+    _VSTD::swap(__tie_, __rhs.__tie_);
+    _VSTD::swap(__fill_, __rhs.__fill_);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+basic_ios<_CharT, _Traits>::set_rdbuf(basic_streambuf<char_type, traits_type>* __sb)
+{
+    ios_base::set_rdbuf(__sb);
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+boolalpha(ios_base& __str)
+{
+    __str.setf(ios_base::boolalpha);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+noboolalpha(ios_base& __str)
+{
+    __str.unsetf(ios_base::boolalpha);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+showbase(ios_base& __str)
+{
+    __str.setf(ios_base::showbase);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+noshowbase(ios_base& __str)
+{
+    __str.unsetf(ios_base::showbase);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+showpoint(ios_base& __str)
+{
+    __str.setf(ios_base::showpoint);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+noshowpoint(ios_base& __str)
+{
+    __str.unsetf(ios_base::showpoint);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+showpos(ios_base& __str)
+{
+    __str.setf(ios_base::showpos);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+noshowpos(ios_base& __str)
+{
+    __str.unsetf(ios_base::showpos);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+skipws(ios_base& __str)
+{
+    __str.setf(ios_base::skipws);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+noskipws(ios_base& __str)
+{
+    __str.unsetf(ios_base::skipws);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+uppercase(ios_base& __str)
+{
+    __str.setf(ios_base::uppercase);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+nouppercase(ios_base& __str)
+{
+    __str.unsetf(ios_base::uppercase);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+unitbuf(ios_base& __str)
+{
+    __str.setf(ios_base::unitbuf);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+nounitbuf(ios_base& __str)
+{
+    __str.unsetf(ios_base::unitbuf);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+internal(ios_base& __str)
+{
+    __str.setf(ios_base::internal, ios_base::adjustfield);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+left(ios_base& __str)
+{
+    __str.setf(ios_base::left, ios_base::adjustfield);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+right(ios_base& __str)
+{
+    __str.setf(ios_base::right, ios_base::adjustfield);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+dec(ios_base& __str)
+{
+    __str.setf(ios_base::dec, ios_base::basefield);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+hex(ios_base& __str)
+{
+    __str.setf(ios_base::hex, ios_base::basefield);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+oct(ios_base& __str)
+{
+    __str.setf(ios_base::oct, ios_base::basefield);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+fixed(ios_base& __str)
+{
+    __str.setf(ios_base::fixed, ios_base::floatfield);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+scientific(ios_base& __str)
+{
+    __str.setf(ios_base::scientific, ios_base::floatfield);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+hexfloat(ios_base& __str)
+{
+    __str.setf(ios_base::fixed | ios_base::scientific, ios_base::floatfield);
+    return __str;
+}
+
+inline _LIBCPP_INLINE_VISIBILITY
+ios_base&
+defaultfloat(ios_base& __str)
+{
+    __str.unsetf(ios_base::floatfield);
+    return __str;
+}
+
+template <class _CharT, class _Traits>
+class __save_flags
+{
+    typedef basic_ios<_CharT, _Traits> __stream_type;
+    typedef typename __stream_type::fmtflags fmtflags;
+
+    __stream_type& __stream_;
+    fmtflags       __fmtflags_;
+    _CharT         __fill_;
+
+    __save_flags(const __save_flags&);
+    __save_flags& operator=(const __save_flags&);
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __save_flags(__stream_type& __stream)
+        : __stream_(__stream),
+          __fmtflags_(__stream.flags()),
+          __fill_(__stream.fill())
+        {}
+    _LIBCPP_INLINE_VISIBILITY
+    ~__save_flags()
+    {
+        __stream_.flags(__fmtflags_);
+        __stream_.fill(__fill_);
+    }
+};
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_IOS

diff --git a/libcxx/include/iosfwd b/libcxx/include/iosfwd
new file mode 100644
index 0000000..eccfd34
--- /dev/null
+++ b/libcxx/include/iosfwd

@@ -0,0 +1,199 @@
+// -*- C++ -*-
+//===--------------------------- iosfwd -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_IOSFWD
+#define _LIBCPP_IOSFWD
+
+/*
+    iosfwd synopsis
+
+namespace std
+{
+
+template<class charT> struct char_traits;
+template<class T>     class allocator;
+
+class ios_base;
+template <class charT, class traits = char_traits<charT> > class basic_ios;
+
+template <class charT, class traits = char_traits<charT> > class basic_streambuf;
+template <class charT, class traits = char_traits<charT> > class basic_istream;
+template <class charT, class traits = char_traits<charT> > class basic_ostream;
+template <class charT, class traits = char_traits<charT> > class basic_iostream;
+
+template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
+    class basic_stringbuf;
+template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
+    class basic_istringstream;
+template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
+    class basic_ostringstream;
+template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
+    class basic_stringstream;
+
+template <class charT, class traits = char_traits<charT> > class basic_filebuf;
+template <class charT, class traits = char_traits<charT> > class basic_ifstream;
+template <class charT, class traits = char_traits<charT> > class basic_ofstream;
+template <class charT, class traits = char_traits<charT> > class basic_fstream;
+
+template <class charT, class traits = char_traits<charT> > class istreambuf_iterator;
+template <class charT, class traits = char_traits<charT> > class ostreambuf_iterator;
+
+typedef basic_ios<char>              ios;
+typedef basic_ios<wchar_t>           wios;
+
+typedef basic_streambuf<char>        streambuf;
+typedef basic_istream<char>          istream;
+typedef basic_ostream<char>          ostream;
+typedef basic_iostream<char>         iostream;
+
+typedef basic_stringbuf<char>        stringbuf;
+typedef basic_istringstream<char>    istringstream;
+typedef basic_ostringstream<char>    ostringstream;
+typedef basic_stringstream<char>     stringstream;
+
+typedef basic_filebuf<char>          filebuf;
+typedef basic_ifstream<char>         ifstream;
+typedef basic_ofstream<char>         ofstream;
+typedef basic_fstream<char>          fstream;
+
+typedef basic_streambuf<wchar_t>     wstreambuf;
+typedef basic_istream<wchar_t>       wistream;
+typedef basic_ostream<wchar_t>       wostream;
+typedef basic_iostream<wchar_t>      wiostream;
+
+typedef basic_stringbuf<wchar_t>     wstringbuf;
+typedef basic_istringstream<wchar_t> wistringstream;
+typedef basic_ostringstream<wchar_t> wostringstream;
+typedef basic_stringstream<wchar_t>  wstringstream;
+
+typedef basic_filebuf<wchar_t>       wfilebuf;
+typedef basic_ifstream<wchar_t>      wifstream;
+typedef basic_ofstream<wchar_t>      wofstream;
+typedef basic_fstream<wchar_t>       wfstream;
+
+template <class state> class fpos;
+typedef fpos<char_traits<char>::state_type>    streampos;
+typedef fpos<char_traits<wchar_t>::state_type> wstreampos;
+
+}  // std
+
+*/
+
+#include <__config>
+#include <wchar.h>  // for mbstate_t
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+class _LIBCPP_TYPE_VIS ios_base;
+
+template<class _CharT>  struct _LIBCPP_TYPE_VIS_ONLY char_traits;
+template<class _Tp>     class _LIBCPP_TYPE_VIS_ONLY allocator;
+
+template <class _CharT, class _Traits = char_traits<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY basic_ios;
+
+template <class _CharT, class _Traits = char_traits<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY basic_streambuf;
+template <class _CharT, class _Traits = char_traits<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY basic_istream;
+template <class _CharT, class _Traits = char_traits<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY basic_ostream;
+template <class _CharT, class _Traits = char_traits<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY basic_iostream;
+
+template <class _CharT, class _Traits = char_traits<_CharT>,
+          class _Allocator = allocator<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY basic_stringbuf;
+template <class _CharT, class _Traits = char_traits<_CharT>,
+          class _Allocator = allocator<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY basic_istringstream;
+template <class _CharT, class _Traits = char_traits<_CharT>,
+          class _Allocator = allocator<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY basic_ostringstream;
+template <class _CharT, class _Traits = char_traits<_CharT>,
+          class _Allocator = allocator<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY basic_stringstream;
+
+template <class _CharT, class _Traits = char_traits<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY basic_filebuf;
+template <class _CharT, class _Traits = char_traits<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY basic_ifstream;
+template <class _CharT, class _Traits = char_traits<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY basic_ofstream;
+template <class _CharT, class _Traits = char_traits<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY basic_fstream;
+
+template <class _CharT, class _Traits = char_traits<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY istreambuf_iterator;
+template <class _CharT, class _Traits = char_traits<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY ostreambuf_iterator;
+
+typedef basic_ios<char>              ios;
+typedef basic_ios<wchar_t>           wios;
+
+typedef basic_streambuf<char>        streambuf;
+typedef basic_istream<char>          istream;
+typedef basic_ostream<char>          ostream;
+typedef basic_iostream<char>         iostream;
+
+typedef basic_stringbuf<char>        stringbuf;
+typedef basic_istringstream<char>    istringstream;
+typedef basic_ostringstream<char>    ostringstream;
+typedef basic_stringstream<char>     stringstream;
+
+typedef basic_filebuf<char>          filebuf;
+typedef basic_ifstream<char>         ifstream;
+typedef basic_ofstream<char>         ofstream;
+typedef basic_fstream<char>          fstream;
+
+typedef basic_streambuf<wchar_t>     wstreambuf;
+typedef basic_istream<wchar_t>       wistream;
+typedef basic_ostream<wchar_t>       wostream;
+typedef basic_iostream<wchar_t>      wiostream;
+
+typedef basic_stringbuf<wchar_t>     wstringbuf;
+typedef basic_istringstream<wchar_t> wistringstream;
+typedef basic_ostringstream<wchar_t> wostringstream;
+typedef basic_stringstream<wchar_t>  wstringstream;
+
+typedef basic_filebuf<wchar_t>       wfilebuf;
+typedef basic_ifstream<wchar_t>      wifstream;
+typedef basic_ofstream<wchar_t>      wofstream;
+typedef basic_fstream<wchar_t>       wfstream;
+
+template <class _State>             class _LIBCPP_TYPE_VIS_ONLY fpos;
+typedef fpos<mbstate_t>    streampos;
+typedef fpos<mbstate_t>    wstreampos;
+#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
+typedef fpos<mbstate_t>    u16streampos;
+typedef fpos<mbstate_t>    u32streampos;
+#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
+
+#if defined(_NEWLIB_VERSION)
+// On newlib, off_t is 'long int'
+typedef long int streamoff;         // for char_traits in <string>
+#else
+typedef long long streamoff;        // for char_traits in <string>
+#endif
+
+template <class _CharT,             // for <stdexcept>
+          class _Traits = char_traits<_CharT>,
+          class _Allocator = allocator<_CharT> >
+    class _LIBCPP_TYPE_VIS_ONLY basic_string;
+typedef basic_string<char, char_traits<char>, allocator<char> > string;
+typedef basic_string<wchar_t, char_traits<wchar_t>, allocator<wchar_t> > wstring;
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_IOSFWD

diff --git a/libcxx/include/iostream b/libcxx/include/iostream
new file mode 100644
index 0000000..136a849
--- /dev/null
+++ b/libcxx/include/iostream

@@ -0,0 +1,64 @@
+// -*- C++ -*-
+//===--------------------------- iostream ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_IOSTREAM
+#define _LIBCPP_IOSTREAM
+
+/*
+    iostream synopsis
+
+#include <ios>
+#include <streambuf>
+#include <istream>
+#include <ostream>
+
+namespace std {
+
+extern istream cin;
+extern ostream cout;
+extern ostream cerr;
+extern ostream clog;
+extern wistream wcin;
+extern wostream wcout;
+extern wostream wcerr;
+extern wostream wclog;
+
+}  // std
+
+*/
+
+#include <__config>
+#include <ios>
+#include <streambuf>
+#include <istream>
+#include <ostream>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#ifndef _LIBCPP_HAS_NO_STDIN
+extern _LIBCPP_FUNC_VIS istream cin;
+extern _LIBCPP_FUNC_VIS wistream wcin;
+#endif
+#ifndef _LIBCPP_HAS_NO_STDOUT
+extern _LIBCPP_FUNC_VIS ostream cout;
+extern _LIBCPP_FUNC_VIS wostream wcout;
+#endif
+extern _LIBCPP_FUNC_VIS ostream cerr;
+extern _LIBCPP_FUNC_VIS wostream wcerr;
+extern _LIBCPP_FUNC_VIS ostream clog;
+extern _LIBCPP_FUNC_VIS wostream wclog;
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_IOSTREAM

diff --git a/libcxx/include/istream b/libcxx/include/istream
new file mode 100644
index 0000000..168a4d0
--- /dev/null
+++ b/libcxx/include/istream

@@ -0,0 +1,1732 @@
+// -*- C++ -*-
+//===--------------------------- istream ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_ISTREAM
+#define _LIBCPP_ISTREAM
+
+/*
+    istream synopsis
+
+template <class charT, class traits = char_traits<charT> >
+class basic_istream
+    : virtual public basic_ios<charT,traits>
+{
+public:
+    // types (inherited from basic_ios (27.5.4)):
+    typedef charT                          char_type;
+    typedef traits                         traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    // 27.7.1.1.1 Constructor/destructor:
+    explicit basic_istream(basic_streambuf<char_type, traits_type>* sb);
+    basic_istream(basic_istream&& rhs);
+    virtual ~basic_istream();
+
+    // 27.7.1.1.2 Assign/swap:
+    basic_istream& operator=(basic_istream&& rhs);
+    void swap(basic_istream& rhs);
+
+    // 27.7.1.1.3 Prefix/suffix:
+    class sentry;
+
+    // 27.7.1.2 Formatted input:
+    basic_istream& operator>>(basic_istream& (*pf)(basic_istream&));
+    basic_istream& operator>>(basic_ios<char_type, traits_type>&
+                              (*pf)(basic_ios<char_type, traits_type>&));
+    basic_istream& operator>>(ios_base& (*pf)(ios_base&));
+    basic_istream& operator>>(basic_streambuf<char_type, traits_type>* sb);
+    basic_istream& operator>>(bool& n);
+    basic_istream& operator>>(short& n);
+    basic_istream& operator>>(unsigned short& n);
+    basic_istream& operator>>(int& n);
+    basic_istream& operator>>(unsigned int& n);
+    basic_istream& operator>>(long& n);
+    basic_istream& operator>>(unsigned long& n);
+    basic_istream& operator>>(long long& n);
+    basic_istream& operator>>(unsigned long long& n);
+    basic_istream& operator>>(float& f);
+    basic_istream& operator>>(double& f);
+    basic_istream& operator>>(long double& f);
+    basic_istream& operator>>(void*& p);
+
+    // 27.7.1.3 Unformatted input:
+    streamsize gcount() const;
+    int_type get();
+    basic_istream& get(char_type& c);
+    basic_istream& get(char_type* s, streamsize n);
+    basic_istream& get(char_type* s, streamsize n, char_type delim);
+    basic_istream& get(basic_streambuf<char_type,traits_type>& sb);
+    basic_istream& get(basic_streambuf<char_type,traits_type>& sb, char_type delim);
+
+    basic_istream& getline(char_type* s, streamsize n);
+    basic_istream& getline(char_type* s, streamsize n, char_type delim);
+
+    basic_istream& ignore(streamsize n = 1, int_type delim = traits_type::eof());
+    int_type peek();
+    basic_istream& read (char_type* s, streamsize n);
+    streamsize readsome(char_type* s, streamsize n);
+
+    basic_istream& putback(char_type c);
+    basic_istream& unget();
+    int sync();
+
+    pos_type tellg();
+    basic_istream& seekg(pos_type);
+    basic_istream& seekg(off_type, ios_base::seekdir);
+protected:
+    basic_istream(const basic_istream& rhs) = delete;
+    basic_istream(basic_istream&& rhs);
+    // 27.7.2.1.2 Assign/swap:
+    basic_istream& operator=(const basic_istream& rhs) = delete;
+    basic_istream& operator=(basic_istream&& rhs);
+    void swap(basic_istream& rhs);
+};
+
+// 27.7.1.2.3 character extraction templates:
+template<class charT, class traits>
+  basic_istream<charT,traits>& operator>>(basic_istream<charT,traits>&, charT&);
+
+template<class traits>
+  basic_istream<char,traits>& operator>>(basic_istream<char,traits>&, unsigned char&);
+
+template<class traits>
+  basic_istream<char,traits>& operator>>(basic_istream<char,traits>&, signed char&);
+
+template<class charT, class traits>
+  basic_istream<charT,traits>& operator>>(basic_istream<charT,traits>&, charT*);
+
+template<class traits>
+  basic_istream<char,traits>& operator>>(basic_istream<char,traits>&, unsigned char*);
+
+template<class traits>
+  basic_istream<char,traits>& operator>>(basic_istream<char,traits>&, signed char*);
+
+template <class charT, class traits>
+  void
+  swap(basic_istream<charT, traits>& x, basic_istream<charT, traits>& y);
+
+typedef basic_istream<char> istream;
+typedef basic_istream<wchar_t> wistream;
+
+template <class charT, class traits = char_traits<charT> >
+class basic_iostream :
+    public basic_istream<charT,traits>,
+    public basic_ostream<charT,traits>
+{
+public:
+    // types:
+    typedef charT                          char_type;
+    typedef traits                         traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    // constructor/destructor
+    explicit basic_iostream(basic_streambuf<char_type, traits_type>* sb);
+    basic_iostream(basic_iostream&& rhs);
+    virtual ~basic_iostream();
+
+    // assign/swap
+    basic_iostream& operator=(basic_iostream&& rhs);
+    void swap(basic_iostream& rhs);
+};
+
+template <class charT, class traits>
+  void
+  swap(basic_iostream<charT, traits>& x, basic_iostream<charT, traits>& y);
+
+typedef basic_iostream<char> iostream;
+typedef basic_iostream<wchar_t> wiostream;
+
+template <class charT, class traits>
+  basic_istream<charT,traits>&
+  ws(basic_istream<charT,traits>& is);
+
+template <class charT, class traits, class T>
+  basic_istream<charT, traits>&
+  operator>>(basic_istream<charT, traits>&& is, T& x);
+
+}  // std
+
+*/
+
+#include <__config>
+#include <ostream>
+
+#include <__undef_min_max>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TYPE_VIS_ONLY basic_istream
+    : virtual public basic_ios<_CharT, _Traits>
+{
+    streamsize __gc_;
+public:
+    // types (inherited from basic_ios (27.5.4)):
+    typedef _CharT                         char_type;
+    typedef _Traits                        traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    // 27.7.1.1.1 Constructor/destructor:
+    explicit basic_istream(basic_streambuf<char_type, traits_type>* __sb);
+    virtual ~basic_istream();
+protected:
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    basic_istream(basic_istream&& __rhs);
+#endif
+    // 27.7.1.1.2 Assign/swap:
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    basic_istream& operator=(basic_istream&& __rhs);
+#endif
+    void swap(basic_istream& __rhs);
+
+#if _LIBCPP_STD_VER > 11
+#ifndef _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+    basic_istream           (const basic_istream& __rhs) = delete;
+    basic_istream& operator=(const basic_istream& __rhs) = delete;
+#else
+    basic_istream           (const basic_istream& __rhs); // not defined
+    basic_istream& operator=(const basic_istream& __rhs); // not defined
+#endif
+#endif
+public:
+
+    // 27.7.1.1.3 Prefix/suffix:
+    class _LIBCPP_TYPE_VIS_ONLY sentry;
+
+    // 27.7.1.2 Formatted input:
+    basic_istream& operator>>(basic_istream& (*__pf)(basic_istream&));
+    basic_istream& operator>>(basic_ios<char_type, traits_type>&
+                              (*__pf)(basic_ios<char_type, traits_type>&));
+    basic_istream& operator>>(ios_base& (*__pf)(ios_base&));
+    basic_istream& operator>>(basic_streambuf<char_type, traits_type>* __sb);
+    basic_istream& operator>>(bool& __n);
+    basic_istream& operator>>(short& __n);
+    basic_istream& operator>>(unsigned short& __n);
+    basic_istream& operator>>(int& __n);
+    basic_istream& operator>>(unsigned int& __n);
+    basic_istream& operator>>(long& __n);
+    basic_istream& operator>>(unsigned long& __n);
+    basic_istream& operator>>(long long& __n);
+    basic_istream& operator>>(unsigned long long& __n);
+    basic_istream& operator>>(float& __f);
+    basic_istream& operator>>(double& __f);
+    basic_istream& operator>>(long double& __f);
+    basic_istream& operator>>(void*& __p);
+
+    // 27.7.1.3 Unformatted input:
+    _LIBCPP_INLINE_VISIBILITY
+    streamsize gcount() const {return __gc_;}
+    int_type get();
+    basic_istream& get(char_type& __c);
+    basic_istream& get(char_type* __s, streamsize __n);
+    basic_istream& get(char_type* __s, streamsize __n, char_type __dlm);
+    basic_istream& get(basic_streambuf<char_type, traits_type>& __sb);
+    basic_istream& get(basic_streambuf<char_type, traits_type>& __sb, char_type __dlm);
+
+    basic_istream& getline(char_type* __s, streamsize __n);
+    basic_istream& getline(char_type* __s, streamsize __n, char_type __dlm);
+
+    basic_istream& ignore(streamsize __n = 1, int_type __dlm = traits_type::eof());
+    int_type peek();
+    basic_istream& read (char_type* __s, streamsize __n);
+    streamsize readsome(char_type* __s, streamsize __n);
+
+    basic_istream& putback(char_type __c);
+    basic_istream& unget();
+    int sync();
+
+    pos_type tellg();
+    basic_istream& seekg(pos_type __pos);
+    basic_istream& seekg(off_type __off, ios_base::seekdir __dir);
+};
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TYPE_VIS_ONLY basic_istream<_CharT, _Traits>::sentry
+{
+    bool __ok_;
+
+    sentry(const sentry&); // = delete;
+    sentry& operator=(const sentry&); // = delete;
+
+public:
+    explicit sentry(basic_istream<_CharT, _Traits>& __is, bool __noskipws = false);
+//    ~sentry() = default;
+
+    _LIBCPP_INLINE_VISIBILITY
+        _LIBCPP_EXPLICIT
+        operator bool() const {return __ok_;}
+};
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>::sentry::sentry(basic_istream<_CharT, _Traits>& __is,
+                                               bool __noskipws)
+    : __ok_(false)
+{
+    if (__is.good())
+    {
+        if (__is.tie())
+            __is.tie()->flush();
+        if (!__noskipws && (__is.flags() & ios_base::skipws))
+        {
+            typedef istreambuf_iterator<_CharT, _Traits> _Ip;
+            const ctype<_CharT>& __ct = use_facet<ctype<_CharT> >(__is.getloc());
+            _Ip __i(__is);
+            _Ip __eof;
+            for (; __i != __eof; ++__i)
+                if (!__ct.is(__ct.space, *__i))
+                    break;
+            if (__i == __eof)
+                __is.setstate(ios_base::failbit | ios_base::eofbit);
+        }
+        __ok_ = __is.good();
+    }
+    else
+        __is.setstate(ios_base::failbit);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>::basic_istream(basic_streambuf<char_type, traits_type>* __sb)
+    : __gc_(0)
+{
+    this->init(__sb);
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>::basic_istream(basic_istream&& __rhs)
+    : __gc_(__rhs.__gc_)
+{
+    __rhs.__gc_ = 0;
+    this->move(__rhs);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator=(basic_istream&& __rhs)
+{
+    swap(__rhs);
+    return *this;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>::~basic_istream()
+{
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+basic_istream<_CharT, _Traits>::swap(basic_istream& __rhs)
+{
+    _VSTD::swap(__gc_, __rhs.__gc_);
+    basic_ios<char_type, traits_type>::swap(__rhs);
+}
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(unsigned short& __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef istreambuf_iterator<char_type, traits_type> _Ip;
+            typedef num_get<char_type, _Ip> _Fp;
+            ios_base::iostate __err = ios_base::goodbit;
+            use_facet<_Fp>(this->getloc()).get(_Ip(*this), _Ip(), *this, __err, __n);
+            this->setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(unsigned int& __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef istreambuf_iterator<char_type, traits_type> _Ip;
+            typedef num_get<char_type, _Ip> _Fp;
+            ios_base::iostate __err = ios_base::goodbit;
+            use_facet<_Fp>(this->getloc()).get(_Ip(*this), _Ip(), *this, __err, __n);
+            this->setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(long& __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef istreambuf_iterator<char_type, traits_type> _Ip;
+            typedef num_get<char_type, _Ip> _Fp;
+            ios_base::iostate __err = ios_base::goodbit;
+            use_facet<_Fp>(this->getloc()).get(_Ip(*this), _Ip(), *this, __err, __n);
+            this->setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(unsigned long& __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef istreambuf_iterator<char_type, traits_type> _Ip;
+            typedef num_get<char_type, _Ip> _Fp;
+            ios_base::iostate __err = ios_base::goodbit;
+            use_facet<_Fp>(this->getloc()).get(_Ip(*this), _Ip(), *this, __err, __n);
+            this->setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(long long& __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef istreambuf_iterator<char_type, traits_type> _Ip;
+            typedef num_get<char_type, _Ip> _Fp;
+            ios_base::iostate __err = ios_base::goodbit;
+            use_facet<_Fp>(this->getloc()).get(_Ip(*this), _Ip(), *this, __err, __n);
+            this->setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(unsigned long long& __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef istreambuf_iterator<char_type, traits_type> _Ip;
+            typedef num_get<char_type, _Ip> _Fp;
+            ios_base::iostate __err = ios_base::goodbit;
+            use_facet<_Fp>(this->getloc()).get(_Ip(*this), _Ip(), *this, __err, __n);
+            this->setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(float& __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef istreambuf_iterator<char_type, traits_type> _Ip;
+            typedef num_get<char_type, _Ip> _Fp;
+            ios_base::iostate __err = ios_base::goodbit;
+            use_facet<_Fp>(this->getloc()).get(_Ip(*this), _Ip(), *this, __err, __n);
+            this->setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(double& __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef istreambuf_iterator<char_type, traits_type> _Ip;
+            typedef num_get<char_type, _Ip> _Fp;
+            ios_base::iostate __err = ios_base::goodbit;
+            use_facet<_Fp>(this->getloc()).get(_Ip(*this), _Ip(), *this, __err, __n);
+            this->setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(long double& __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef istreambuf_iterator<char_type, traits_type> _Ip;
+            typedef num_get<char_type, _Ip> _Fp;
+            ios_base::iostate __err = ios_base::goodbit;
+            use_facet<_Fp>(this->getloc()).get(_Ip(*this), _Ip(), *this, __err, __n);
+            this->setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(bool& __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef istreambuf_iterator<char_type, traits_type> _Ip;
+            typedef num_get<char_type, _Ip> _Fp;
+            ios_base::iostate __err = ios_base::goodbit;
+            use_facet<_Fp>(this->getloc()).get(_Ip(*this), _Ip(), *this, __err, __n);
+            this->setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(void*& __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef istreambuf_iterator<char_type, traits_type> _Ip;
+            typedef num_get<char_type, _Ip> _Fp;
+            ios_base::iostate __err = ios_base::goodbit;
+            use_facet<_Fp>(this->getloc()).get(_Ip(*this), _Ip(), *this, __err, __n);
+            this->setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(short& __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef istreambuf_iterator<char_type, traits_type> _Ip;
+            typedef num_get<char_type, _Ip> _Fp;
+            ios_base::iostate __err = ios_base::goodbit;
+            long __temp;
+            use_facet<_Fp>(this->getloc()).get(_Ip(*this), _Ip(), *this, __err, __temp);
+            if (__temp < numeric_limits<short>::min())
+            {
+                __err |= ios_base::failbit;
+                __n = numeric_limits<short>::min();
+            }
+            else if (__temp > numeric_limits<short>::max())
+            {
+                __err |= ios_base::failbit;
+                __n = numeric_limits<short>::max();
+            }
+            else
+                __n = static_cast<short>(__temp);
+            this->setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(int& __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef istreambuf_iterator<char_type, traits_type> _Ip;
+            typedef num_get<char_type, _Ip> _Fp;
+            ios_base::iostate __err = ios_base::goodbit;
+            long __temp;
+            use_facet<_Fp>(this->getloc()).get(_Ip(*this), _Ip(), *this, __err, __temp);
+            if (__temp < numeric_limits<int>::min())
+            {
+                __err |= ios_base::failbit;
+                __n = numeric_limits<int>::min();
+            }
+            else if (__temp > numeric_limits<int>::max())
+            {
+                __err |= ios_base::failbit;
+                __n = numeric_limits<int>::max();
+            }
+            else
+                __n = static_cast<int>(__temp);
+            this->setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(basic_istream& (*__pf)(basic_istream&))
+{
+    return __pf(*this);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(basic_ios<char_type, traits_type>&
+                                           (*__pf)(basic_ios<char_type, traits_type>&))
+{
+    __pf(*this);
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(ios_base& (*__pf)(ios_base&))
+{
+    __pf(*this);
+    return *this;
+}
+
+template<class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is, _CharT* __s)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typename basic_istream<_CharT, _Traits>::sentry __sen(__is);
+        if (__sen)
+        {
+            streamsize __n = __is.width();
+            if (__n <= 0)
+                __n = numeric_limits<streamsize>::max() / sizeof(_CharT) - 1;
+            streamsize __c = 0;
+            const ctype<_CharT>& __ct = use_facet<ctype<_CharT> >(__is.getloc());
+            ios_base::iostate __err = ios_base::goodbit;
+            while (__c < __n-1)
+            {
+                typename _Traits::int_type __i = __is.rdbuf()->sgetc();
+                if (_Traits::eq_int_type(__i, _Traits::eof()))
+                {
+                   __err |= ios_base::eofbit;
+                   break;
+                }
+                _CharT __ch = _Traits::to_char_type(__i);
+                if (__ct.is(__ct.space, __ch))
+                    break;
+                *__s++ = __ch;
+                ++__c;
+                 __is.rdbuf()->sbumpc();
+            }
+            *__s = _CharT();
+            __is.width(0);
+            if (__c == 0)
+               __err |= ios_base::failbit;
+            __is.setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __is.__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __is;
+}
+
+template<class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<char, _Traits>&
+operator>>(basic_istream<char, _Traits>& __is, unsigned char* __s)
+{
+    return __is >> (char*)__s;
+}
+
+template<class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<char, _Traits>&
+operator>>(basic_istream<char, _Traits>& __is, signed char* __s)
+{
+    return __is >> (char*)__s;
+}
+
+template<class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is, _CharT& __c)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typename basic_istream<_CharT, _Traits>::sentry __sen(__is);
+        if (__sen)
+        {
+            typename _Traits::int_type __i = __is.rdbuf()->sbumpc();
+            if (_Traits::eq_int_type(__i, _Traits::eof()))
+                __is.setstate(ios_base::eofbit | ios_base::failbit);
+            else
+                __c = _Traits::to_char_type(__i);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __is.__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __is;
+}
+
+template<class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<char, _Traits>&
+operator>>(basic_istream<char, _Traits>& __is, unsigned char& __c)
+{
+    return __is >> (char&)__c;
+}
+
+template<class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<char, _Traits>&
+operator>>(basic_istream<char, _Traits>& __is, signed char& __c)
+{
+    return __is >> (char&)__c;
+}
+
+template<class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::operator>>(basic_streambuf<char_type, traits_type>* __sb)
+{
+    __gc_ = 0;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this, true);
+        if (__s)
+        {
+            if (__sb)
+            {
+#ifndef _LIBCPP_NO_EXCEPTIONS
+                try
+                {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+                    ios_base::iostate __err = ios_base::goodbit;
+                    while (true)
+                    {
+                        typename traits_type::int_type __i = this->rdbuf()->sgetc();
+                        if (traits_type::eq_int_type(__i, _Traits::eof()))
+                        {
+                           __err |= ios_base::eofbit;
+                           break;
+                        }
+                        if (traits_type::eq_int_type(
+                                __sb->sputc(traits_type::to_char_type(__i)),
+                                traits_type::eof()))
+                            break;
+                        ++__gc_;
+                        this->rdbuf()->sbumpc();
+                    }
+                    if (__gc_ == 0)
+                       __err |= ios_base::failbit;
+                    this->setstate(__err);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+                }
+                catch (...)
+                {
+                    if (__gc_ == 0)
+                        this->__set_failbit_and_consider_rethrow();
+                }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            }
+            else
+                this->setstate(ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template<class _CharT, class _Traits>
+typename basic_istream<_CharT, _Traits>::int_type
+basic_istream<_CharT, _Traits>::get()
+{
+    __gc_ = 0;
+    int_type __r = traits_type::eof();
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this, true);
+        if (__s)
+        {
+            __r = this->rdbuf()->sbumpc();
+            if (traits_type::eq_int_type(__r, traits_type::eof()))
+               this->setstate(ios_base::failbit | ios_base::eofbit);
+            else
+                __gc_ = 1;
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __r;
+}
+
+template<class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::get(char_type& __c)
+{
+    int_type __ch = get();
+    if (__ch != traits_type::eof())
+        __c = traits_type::to_char_type(__ch);
+    return *this;
+}
+
+template<class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::get(char_type* __s, streamsize __n, char_type __dlm)
+{
+    __gc_ = 0;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __sen(*this, true);
+        if (__sen)
+        {
+            if (__n > 0)
+            {
+                ios_base::iostate __err = ios_base::goodbit;
+                while (__gc_ < __n-1)
+                {
+                    int_type __i = this->rdbuf()->sgetc();
+                    if (traits_type::eq_int_type(__i, traits_type::eof()))
+                    {
+                       __err |= ios_base::eofbit;
+                       break;
+                    }
+                    char_type __ch = traits_type::to_char_type(__i);
+                    if (traits_type::eq(__ch, __dlm))
+                        break;
+                    *__s++ = __ch;
+                    ++__gc_;
+                     this->rdbuf()->sbumpc();
+                }
+                *__s = char_type();
+                if (__gc_ == 0)
+                   __err |= ios_base::failbit;
+                this->setstate(__err);
+            }
+            else
+                this->setstate(ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template<class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::get(char_type* __s, streamsize __n)
+{
+    return get(__s, __n, this->widen('\n'));
+}
+
+template<class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::get(basic_streambuf<char_type, traits_type>& __sb,
+                                    char_type __dlm)
+{
+    __gc_ = 0;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __sen(*this, true);
+        if (__sen)
+        {
+            ios_base::iostate __err = ios_base::goodbit;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+            try
+            {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+                while (true)
+                {
+                    typename traits_type::int_type __i = this->rdbuf()->sgetc();
+                    if (traits_type::eq_int_type(__i, traits_type::eof()))
+                    {
+                       __err |= ios_base::eofbit;
+                       break;
+                    }
+                    char_type __ch = traits_type::to_char_type(__i);
+                    if (traits_type::eq(__ch, __dlm))
+                        break;
+                    if (traits_type::eq_int_type(__sb.sputc(__ch), traits_type::eof()))
+                        break;
+                    ++__gc_;
+                    this->rdbuf()->sbumpc();
+                }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+            }
+            catch (...)
+            {
+            }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            if (__gc_ == 0)
+               __err |= ios_base::failbit;
+            this->setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template<class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::get(basic_streambuf<char_type, traits_type>& __sb)
+{
+    return get(__sb, this->widen('\n'));
+}
+
+template<class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::getline(char_type* __s, streamsize __n, char_type __dlm)
+{
+    __gc_ = 0;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __sen(*this, true);
+        if (__sen)
+        {
+            ios_base::iostate __err = ios_base::goodbit;
+            while (true)
+            {
+                typename traits_type::int_type __i = this->rdbuf()->sgetc();
+                if (traits_type::eq_int_type(__i, traits_type::eof()))
+                {
+                   __err |= ios_base::eofbit;
+                   break;
+                }
+                char_type __ch = traits_type::to_char_type(__i);
+                if (traits_type::eq(__ch, __dlm))
+                {
+                    this->rdbuf()->sbumpc();
+                    ++__gc_;
+                    break;
+                }
+                if (__gc_ >= __n-1)
+                {
+                    __err |= ios_base::failbit;
+                    break;
+                }
+                *__s++ = __ch;
+                this->rdbuf()->sbumpc();
+                ++__gc_;
+            }
+            if (__n > 0)
+                *__s = char_type();
+            if (__gc_ == 0)
+               __err |= ios_base::failbit;
+            this->setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template<class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::getline(char_type* __s, streamsize __n)
+{
+    return getline(__s, __n, this->widen('\n'));
+}
+
+template<class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::ignore(streamsize __n, int_type __dlm)
+{
+    __gc_ = 0;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __sen(*this, true);
+        if (__sen)
+        {
+            ios_base::iostate __err = ios_base::goodbit;
+            if (__n == numeric_limits<streamsize>::max())
+            {
+                while (true)
+                {
+                    typename traits_type::int_type __i = this->rdbuf()->sbumpc();
+                    if (traits_type::eq_int_type(__i, traits_type::eof()))
+                    {
+                       __err |= ios_base::eofbit;
+                       break;
+                    }
+                    ++__gc_;
+                    if (traits_type::eq_int_type(__i, __dlm))
+                        break;
+                }
+            }
+            else
+            {
+                while (__gc_ < __n)
+                {
+                    typename traits_type::int_type __i = this->rdbuf()->sbumpc();
+                    if (traits_type::eq_int_type(__i, traits_type::eof()))
+                    {
+                       __err |= ios_base::eofbit;
+                       break;
+                    }
+                    ++__gc_;
+                    if (traits_type::eq_int_type(__i, __dlm))
+                        break;
+                }
+            }
+            this->setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template<class _CharT, class _Traits>
+typename basic_istream<_CharT, _Traits>::int_type
+basic_istream<_CharT, _Traits>::peek()
+{
+    __gc_ = 0;
+    int_type __r = traits_type::eof();
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __sen(*this, true);
+        if (__sen)
+        {
+            __r = this->rdbuf()->sgetc();
+            if (traits_type::eq_int_type(__r, traits_type::eof()))
+                this->setstate(ios_base::eofbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __r;
+}
+
+template<class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::read(char_type* __s, streamsize __n)
+{
+    __gc_ = 0;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __sen(*this, true);
+        if (__sen)
+        {
+            __gc_ = this->rdbuf()->sgetn(__s, __n);
+            if (__gc_ != __n)
+                this->setstate(ios_base::failbit | ios_base::eofbit);
+        }
+        else
+            this->setstate(ios_base::failbit);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template<class _CharT, class _Traits>
+streamsize
+basic_istream<_CharT, _Traits>::readsome(char_type* __s, streamsize __n)
+{
+    __gc_ = 0;
+    streamsize __c = this->rdbuf()->in_avail();
+    switch (__c)
+    {
+    case -1:
+        this->setstate(ios_base::eofbit);
+        break;
+    case 0:
+        break;
+    default:
+        read(__s, _VSTD::min(__c, __n));
+        break;
+    }
+    return __gc_;
+}
+
+template<class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::putback(char_type __c)
+{
+    __gc_ = 0;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        this->clear(this->rdstate() & ~ios_base::eofbit);
+        sentry __sen(*this, true);
+        if (__sen)
+        {
+            if (this->rdbuf() == 0 || this->rdbuf()->sputbackc(__c) == traits_type::eof())
+                this->setstate(ios_base::badbit);
+        }
+        else
+            this->setstate(ios_base::failbit);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template<class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::unget()
+{
+    __gc_ = 0;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        this->clear(this->rdstate() & ~ios_base::eofbit);
+        sentry __sen(*this, true);
+        if (__sen)
+        {
+            if (this->rdbuf() == 0 || this->rdbuf()->sungetc() == traits_type::eof())
+                this->setstate(ios_base::badbit);
+        }
+        else
+            this->setstate(ios_base::failbit);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template<class _CharT, class _Traits>
+int
+basic_istream<_CharT, _Traits>::sync()
+{
+    int __r = 0;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __sen(*this, true);
+        if (__sen)
+        {
+            if (this->rdbuf() == 0)
+                return -1;
+            if (this->rdbuf()->pubsync() == -1)
+            {
+                this->setstate(ios_base::badbit);
+                return -1;
+            }
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __r;
+}
+
+template<class _CharT, class _Traits>
+typename basic_istream<_CharT, _Traits>::pos_type
+basic_istream<_CharT, _Traits>::tellg()
+{
+    pos_type __r(-1);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __sen(*this, true);
+        if (__sen)
+            __r = this->rdbuf()->pubseekoff(0, ios_base::cur, ios_base::in);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __r;
+}
+
+template<class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::seekg(pos_type __pos)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        this->clear(this->rdstate() & ~ios_base::eofbit);
+        sentry __sen(*this, true);
+        if (__sen)
+        {
+            if (this->rdbuf()->pubseekpos(__pos, ios_base::in) == pos_type(-1))
+                this->setstate(ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template<class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+basic_istream<_CharT, _Traits>::seekg(off_type __off, ios_base::seekdir __dir)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __sen(*this, true);
+        if (__sen)
+        {
+            if (this->rdbuf()->pubseekoff(__off, __dir, ios_base::in) == pos_type(-1))
+                this->setstate(ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_istream<_CharT, _Traits>&
+ws(basic_istream<_CharT, _Traits>& __is)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typename basic_istream<_CharT, _Traits>::sentry __sen(__is, true);
+        if (__sen)
+        {
+            const ctype<_CharT>& __ct = use_facet<ctype<_CharT> >(__is.getloc());
+            while (true)
+            {
+                typename _Traits::int_type __i = __is.rdbuf()->sgetc();
+                if (_Traits::eq_int_type(__i, _Traits::eof()))
+                {
+                   __is.setstate(ios_base::eofbit);
+                   break;
+                }
+                if (!__ct.is(__ct.space, _Traits::to_char_type(__i)))
+                    break;
+                __is.rdbuf()->sbumpc();
+            }
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __is.__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __is;
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>&& __is, _Tp& __x)
+{
+    __is >> __x;
+    return __is;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TYPE_VIS_ONLY basic_iostream
+    : public basic_istream<_CharT, _Traits>,
+      public basic_ostream<_CharT, _Traits>
+{
+public:
+    // types:
+    typedef _CharT                         char_type;
+    typedef _Traits                        traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    // constructor/destructor
+    explicit basic_iostream(basic_streambuf<char_type, traits_type>* __sb);
+    virtual ~basic_iostream();
+protected:
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    basic_iostream(basic_iostream&& __rhs);
+#endif
+
+    // assign/swap
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    basic_iostream& operator=(basic_iostream&& __rhs);
+#endif
+    void swap(basic_iostream& __rhs);
+public:
+};
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_iostream<_CharT, _Traits>::basic_iostream(basic_streambuf<char_type, traits_type>* __sb)
+    : basic_istream<_CharT, _Traits>(__sb)
+{
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_iostream<_CharT, _Traits>::basic_iostream(basic_iostream&& __rhs)
+    : basic_istream<_CharT, _Traits>(_VSTD::move(__rhs))
+{
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_iostream<_CharT, _Traits>&
+basic_iostream<_CharT, _Traits>::operator=(basic_iostream&& __rhs)
+{
+    swap(__rhs);
+    return *this;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits>
+basic_iostream<_CharT, _Traits>::~basic_iostream()
+{
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+basic_iostream<_CharT, _Traits>::swap(basic_iostream& __rhs)
+{
+    basic_istream<char_type, traits_type>::swap(__rhs);
+}
+
+template<class _CharT, class _Traits, class _Allocator>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is,
+           basic_string<_CharT, _Traits, _Allocator>& __str)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typename basic_istream<_CharT, _Traits>::sentry __sen(__is);
+        if (__sen)
+        {
+            __str.clear();
+            streamsize __n = __is.width();
+            if (__n <= 0)
+                __n = __str.max_size();
+            if (__n <= 0)
+                __n = numeric_limits<streamsize>::max();
+            streamsize __c = 0;
+            const ctype<_CharT>& __ct = use_facet<ctype<_CharT> >(__is.getloc());
+            ios_base::iostate __err = ios_base::goodbit;
+            while (__c < __n)
+            {
+                typename _Traits::int_type __i = __is.rdbuf()->sgetc();
+                if (_Traits::eq_int_type(__i, _Traits::eof()))
+                {
+                   __err |= ios_base::eofbit;
+                   break;
+                }
+                _CharT __ch = _Traits::to_char_type(__i);
+                if (__ct.is(__ct.space, __ch))
+                    break;
+                __str.push_back(__ch);
+                ++__c;
+                 __is.rdbuf()->sbumpc();
+            }
+            __is.width(0);
+            if (__c == 0)
+               __err |= ios_base::failbit;
+            __is.setstate(__err);
+        }
+        else
+            __is.setstate(ios_base::failbit);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __is.__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __is;
+}
+
+template<class _CharT, class _Traits, class _Allocator>
+basic_istream<_CharT, _Traits>&
+getline(basic_istream<_CharT, _Traits>& __is,
+        basic_string<_CharT, _Traits, _Allocator>& __str, _CharT __dlm)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typename basic_istream<_CharT, _Traits>::sentry __sen(__is, true);
+        if (__sen)
+        {
+            __str.clear();
+            ios_base::iostate __err = ios_base::goodbit;
+            streamsize __extr = 0;
+            while (true)
+            {
+                typename _Traits::int_type __i = __is.rdbuf()->sbumpc();
+                if (_Traits::eq_int_type(__i, _Traits::eof()))
+                {
+                   __err |= ios_base::eofbit;
+                   break;
+                }
+                ++__extr;
+                _CharT __ch = _Traits::to_char_type(__i);
+                if (_Traits::eq(__ch, __dlm))
+                    break;
+                __str.push_back(__ch);
+                if (__str.size() == __str.max_size())
+                {
+                    __err |= ios_base::failbit;
+                    break;
+                }
+            }
+            if (__extr == 0)
+               __err |= ios_base::failbit;
+            __is.setstate(__err);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __is.__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __is;
+}
+
+template<class _CharT, class _Traits, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>&
+getline(basic_istream<_CharT, _Traits>& __is,
+        basic_string<_CharT, _Traits, _Allocator>& __str)
+{
+    return getline(__is, __str, __is.widen('\n'));
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template<class _CharT, class _Traits, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>&
+getline(basic_istream<_CharT, _Traits>&& __is,
+        basic_string<_CharT, _Traits, _Allocator>& __str, _CharT __dlm)
+{
+    return getline(__is, __str, __dlm);
+}
+
+template<class _CharT, class _Traits, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_istream<_CharT, _Traits>&
+getline(basic_istream<_CharT, _Traits>&& __is,
+        basic_string<_CharT, _Traits, _Allocator>& __str)
+{
+    return getline(__is, __str, __is.widen('\n'));
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits, size_t _Size>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is, bitset<_Size>& __x)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typename basic_istream<_CharT, _Traits>::sentry __sen(__is);
+        if (__sen)
+        {
+            basic_string<_CharT, _Traits> __str;
+            const ctype<_CharT>& __ct = use_facet<ctype<_CharT> >(__is.getloc());
+            streamsize __c = 0;
+            ios_base::iostate __err = ios_base::goodbit;
+            _CharT __zero = __ct.widen('0');
+            _CharT __one = __ct.widen('1');
+            while (__c < _Size)
+            {
+                typename _Traits::int_type __i = __is.rdbuf()->sgetc();
+                if (_Traits::eq_int_type(__i, _Traits::eof()))
+                {
+                   __err |= ios_base::eofbit;
+                   break;
+                }
+                _CharT __ch = _Traits::to_char_type(__i);
+                if (!_Traits::eq(__ch, __zero) && !_Traits::eq(__ch, __one))
+                    break;
+                __str.push_back(__ch);
+                ++__c;
+                 __is.rdbuf()->sbumpc();
+            }
+            __x = bitset<_Size>(__str);
+            if (__c == 0)
+               __err |= ios_base::failbit;
+            __is.setstate(__err);
+        }
+        else
+            __is.setstate(ios_base::failbit);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __is.__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __is;
+}
+
+_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_TYPE_VIS basic_istream<char>)
+_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_TYPE_VIS basic_istream<wchar_t>)
+_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_TYPE_VIS basic_iostream<char>)
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_ISTREAM

diff --git a/libcxx/include/iterator b/libcxx/include/iterator
new file mode 100644
index 0000000..9ac4351
--- /dev/null
+++ b/libcxx/include/iterator

@@ -0,0 +1,1616 @@
+// -*- C++ -*-
+//===-------------------------- iterator ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_ITERATOR
+#define _LIBCPP_ITERATOR
+
+/*
+    iterator synopsis
+
+namespace std
+{
+
+template<class Iterator>
+struct iterator_traits
+{
+    typedef typename Iterator::difference_type difference_type;
+    typedef typename Iterator::value_type value_type;
+    typedef typename Iterator::pointer pointer;
+    typedef typename Iterator::reference reference;
+    typedef typename Iterator::iterator_category iterator_category;
+};
+
+template<class T>
+struct iterator_traits<T*>
+{
+    typedef ptrdiff_t difference_type;
+    typedef T value_type;
+    typedef T* pointer;
+    typedef T& reference;
+    typedef random_access_iterator_tag iterator_category;
+};
+
+template<class T>
+struct iterator_traits<const T*>
+{
+    typedef ptrdiff_t difference_type;
+    typedef T value_type;
+    typedef const T* pointer;
+    typedef const T& reference;
+    typedef random_access_iterator_tag iterator_category;
+};
+
+template<class Category, class T, class Distance = ptrdiff_t,
+         class Pointer = T*, class Reference = T&>
+struct iterator
+{
+    typedef T         value_type;
+    typedef Distance  difference_type;
+    typedef Pointer   pointer;
+    typedef Reference reference;
+    typedef Category  iterator_category;
+};
+
+struct input_iterator_tag  {};
+struct output_iterator_tag {};
+struct forward_iterator_tag       : public input_iterator_tag         {};
+struct bidirectional_iterator_tag : public forward_iterator_tag       {};
+struct random_access_iterator_tag : public bidirectional_iterator_tag {};
+
+// extension: second argument not conforming to C++03
+template <class InputIterator>
+void advance(InputIterator& i,
+             typename iterator_traits<InputIterator>::difference_type n);
+
+template <class InputIterator>
+typename iterator_traits<InputIterator>::difference_type
+distance(InputIterator first, InputIterator last);
+
+template <class Iterator>
+class reverse_iterator
+    : public iterator<typename iterator_traits<Iterator>::iterator_category,
+                      typename iterator_traits<Iterator>::value_type,
+                      typename iterator_traits<Iterator>::difference_type,
+                      typename iterator_traits<Iterator>::pointer,
+                      typename iterator_traits<Iterator>::reference>
+{
+protected:
+    Iterator current;
+public:
+    typedef Iterator                                            iterator_type;
+    typedef typename iterator_traits<Iterator>::difference_type difference_type;
+    typedef typename iterator_traits<Iterator>::reference       reference;
+    typedef typename iterator_traits<Iterator>::pointer         pointer;
+
+    reverse_iterator();
+    explicit reverse_iterator(Iterator x);
+    template <class U> reverse_iterator(const reverse_iterator<U>& u);
+    Iterator base() const;
+    reference operator*() const;
+    pointer   operator->() const;
+    reverse_iterator& operator++();
+    reverse_iterator  operator++(int);
+    reverse_iterator& operator--();
+    reverse_iterator  operator--(int);
+    reverse_iterator  operator+ (difference_type n) const;
+    reverse_iterator& operator+=(difference_type n);
+    reverse_iterator  operator- (difference_type n) const;
+    reverse_iterator& operator-=(difference_type n);
+    reference         operator[](difference_type n) const;
+};
+
+template <class Iterator1, class Iterator2>
+bool
+operator==(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
+
+template <class Iterator1, class Iterator2>
+bool
+operator<(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
+
+template <class Iterator1, class Iterator2>
+bool
+operator!=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
+
+template <class Iterator1, class Iterator2>
+bool
+operator>(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
+
+template <class Iterator1, class Iterator2>
+bool
+operator>=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
+
+template <class Iterator1, class Iterator2>
+bool
+operator<=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
+
+template <class Iterator1, class Iterator2>
+typename reverse_iterator<Iterator1>::difference_type
+operator-(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
+
+template <class Iterator>
+reverse_iterator<Iterator>
+operator+(typename reverse_iterator<Iterator>::difference_type n, const reverse_iterator<Iterator>& x);
+
+template <class Iterator> reverse_iterator<Iterator> make_reverse_iterator(Iterator i); // C++14
+
+template <class Container>
+class back_insert_iterator
+{
+protected:
+    Container* container;
+public:
+    typedef Container                   container_type;
+    typedef void                        value_type;
+    typedef void                        difference_type;
+    typedef back_insert_iterator<Cont>& reference;
+    typedef void                        pointer;
+
+    explicit back_insert_iterator(Container& x);
+    back_insert_iterator& operator=(const typename Container::value_type& value);
+    back_insert_iterator& operator*();
+    back_insert_iterator& operator++();
+    back_insert_iterator  operator++(int);
+};
+
+template <class Container> back_insert_iterator<Container> back_inserter(Container& x);
+
+template <class Container>
+class front_insert_iterator
+{
+protected:
+    Container* container;
+public:
+    typedef Container                    container_type;
+    typedef void                         value_type;
+    typedef void                         difference_type;
+    typedef front_insert_iterator<Cont>& reference;
+    typedef void                         pointer;
+
+    explicit front_insert_iterator(Container& x);
+    front_insert_iterator& operator=(const typename Container::value_type& value);
+    front_insert_iterator& operator*();
+    front_insert_iterator& operator++();
+    front_insert_iterator  operator++(int);
+};
+
+template <class Container> front_insert_iterator<Container> front_inserter(Container& x);
+
+template <class Container>
+class insert_iterator
+{
+protected:
+    Container* container;
+    typename Container::iterator iter;
+public:
+    typedef Container              container_type;
+    typedef void                   value_type;
+    typedef void                   difference_type;
+    typedef insert_iterator<Cont>& reference;
+    typedef void                   pointer;
+
+    insert_iterator(Container& x, typename Container::iterator i);
+    insert_iterator& operator=(const typename Container::value_type& value);
+    insert_iterator& operator*();
+    insert_iterator& operator++();
+    insert_iterator& operator++(int);
+};
+
+template <class Container, class Iterator>
+insert_iterator<Container> inserter(Container& x, Iterator i);
+
+template <class T, class charT = char, class traits = char_traits<charT>, class Distance = ptrdiff_t>
+class istream_iterator
+    : public iterator<input_iterator_tag, T, Distance, const T*, const T&>
+{
+public:
+    typedef charT char_type;
+    typedef traits traits_type;
+    typedef basic_istream<charT,traits> istream_type;
+
+    constexpr istream_iterator();
+    istream_iterator(istream_type& s);
+    istream_iterator(const istream_iterator& x);
+    ~istream_iterator();
+
+    const T& operator*() const;
+    const T* operator->() const;
+    istream_iterator& operator++();
+    istream_iterator  operator++(int);
+};
+
+template <class T, class charT, class traits, class Distance>
+bool operator==(const istream_iterator<T,charT,traits,Distance>& x,
+                const istream_iterator<T,charT,traits,Distance>& y);
+template <class T, class charT, class traits, class Distance>
+bool operator!=(const istream_iterator<T,charT,traits,Distance>& x,
+                const istream_iterator<T,charT,traits,Distance>& y);
+
+template <class T, class charT = char, class traits = char_traits<charT> >
+class ostream_iterator
+    : public iterator<output_iterator_tag, void, void, void ,void>
+{
+public:
+    typedef charT char_type;
+    typedef traits traits_type;
+    typedef basic_ostream<charT,traits> ostream_type;
+
+    ostream_iterator(ostream_type& s);
+    ostream_iterator(ostream_type& s, const charT* delimiter);
+    ostream_iterator(const ostream_iterator& x);
+    ~ostream_iterator();
+    ostream_iterator& operator=(const T& value);
+
+    ostream_iterator& operator*();
+    ostream_iterator& operator++();
+    ostream_iterator& operator++(int);
+};
+
+template<class charT, class traits = char_traits<charT> >
+class istreambuf_iterator
+    : public iterator<input_iterator_tag, charT,
+                      typename traits::off_type, unspecified,
+                      charT>
+{
+public:
+    typedef charT                         char_type;
+    typedef traits                        traits_type;
+    typedef typename traits::int_type     int_type;
+    typedef basic_streambuf<charT,traits> streambuf_type;
+    typedef basic_istream<charT,traits>   istream_type;
+
+    istreambuf_iterator() noexcept;
+    istreambuf_iterator(istream_type& s) noexcept;
+    istreambuf_iterator(streambuf_type* s) noexcept;
+    istreambuf_iterator(a-private-type) noexcept;
+
+    charT                operator*() const;
+    pointer operator->() const;
+    istreambuf_iterator& operator++();
+    a-private-type       operator++(int);
+
+    bool equal(const istreambuf_iterator& b) const;
+};
+
+template <class charT, class traits>
+bool operator==(const istreambuf_iterator<charT,traits>& a,
+                const istreambuf_iterator<charT,traits>& b);
+template <class charT, class traits>
+bool operator!=(const istreambuf_iterator<charT,traits>& a,
+                const istreambuf_iterator<charT,traits>& b);
+
+template <class charT, class traits = char_traits<charT> >
+class ostreambuf_iterator
+    : public iterator<output_iterator_tag, void, void, void, void>
+{
+public:
+    typedef charT                         char_type;
+    typedef traits                        traits_type;
+    typedef basic_streambuf<charT,traits> streambuf_type;
+    typedef basic_ostream<charT,traits>   ostream_type;
+
+    ostreambuf_iterator(ostream_type& s) noexcept;
+    ostreambuf_iterator(streambuf_type* s) noexcept;
+    ostreambuf_iterator& operator=(charT c);
+    ostreambuf_iterator& operator*();
+    ostreambuf_iterator& operator++();
+    ostreambuf_iterator& operator++(int);
+    bool failed() const noexcept;
+};
+
+template <class C> auto begin(C& c) -> decltype(c.begin());
+template <class C> auto begin(const C& c) -> decltype(c.begin());
+template <class C> auto end(C& c) -> decltype(c.end());
+template <class C> auto end(const C& c) -> decltype(c.end());
+template <class T, size_t N> T* begin(T (&array)[N]);
+template <class T, size_t N> T* end(T (&array)[N]);
+
+template <class C> auto cbegin(const C& c) -> decltype(std::begin(c));        // C++14
+template <class C> auto cend(const C& c) -> decltype(std::end(c));            // C++14
+template <class C> auto rbegin(C& c) -> decltype(c.rbegin());                 // C++14
+template <class C> auto rbegin(const C& c) -> decltype(c.rbegin());           // C++14
+template <class C> auto rend(C& c) -> decltype(c.rend());                     // C++14
+template <class C> auto rend(const C& c) -> decltype(c.rend());               // C++14
+template <class E> reverse_iterator<const E*> rbegin(initializer_list<E> il); // C++14
+template <class E> reverse_iterator<const E*> rend(initializer_list<E> il);   // C++14
+template <class T, size_t N> reverse_iterator<T*> rbegin(T (&array)[N]);      // C++14
+template <class T, size_t N> reverse_iterator<T*> rend(T (&array)[N]);        // C++14
+template <class C> auto crbegin(const C& c) -> decltype(std::rbegin(c));      // C++14
+template <class C> auto crend(const C& c) -> decltype(std::rend(c));          // C++14
+
+// 24.8, container access:
+template <class C> constexpr auto size(const C& c) -> decltype(c.size());         // C++17
+template <class T, size_t N> constexpr size_t size(const T (&array)[N]) noexcept; // C++17
+template <class C> constexpr auto empty(const C& c) -> decltype(c.empty());       // C++17
+template <class T, size_t N> constexpr bool empty(const T (&array)[N]) noexcept;  // C++17
+template <class E> constexpr bool empty(initializer_list<E> il) noexcept;         // C++17
+template <class C> constexpr auto data(C& c) -> decltype(c.data());               // C++17
+template <class C> constexpr auto data(const C& c) -> decltype(c.data());         // C++17
+template <class T, size_t N> constexpr T* data(T (&array)[N]) noexcept;           // C++17
+template <class E> constexpr const E* data(initializer_list<E> il) noexcept;      // C++17
+
+}  // std
+
+*/
+
+#include <__config>
+#include <__functional_base>
+#include <type_traits>
+#include <cstddef>
+#include <iosfwd>
+#include <initializer_list>
+#ifdef __APPLE__
+#include <Availability.h>
+#endif
+
+#include <__debug>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+struct _LIBCPP_TYPE_VIS_ONLY input_iterator_tag {};
+struct _LIBCPP_TYPE_VIS_ONLY output_iterator_tag {};
+struct _LIBCPP_TYPE_VIS_ONLY forward_iterator_tag       : public input_iterator_tag {};
+struct _LIBCPP_TYPE_VIS_ONLY bidirectional_iterator_tag : public forward_iterator_tag {};
+struct _LIBCPP_TYPE_VIS_ONLY random_access_iterator_tag : public bidirectional_iterator_tag {};
+
+template <class _Tp>
+struct __has_iterator_category
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Up> static __two __test(...);
+    template <class _Up> static char __test(typename _Up::iterator_category* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+template <class _Iter, bool> struct __iterator_traits_impl {};
+
+template <class _Iter>
+struct __iterator_traits_impl<_Iter, true>
+{
+    typedef typename _Iter::difference_type   difference_type;
+    typedef typename _Iter::value_type        value_type;
+    typedef typename _Iter::pointer           pointer;
+    typedef typename _Iter::reference         reference;
+    typedef typename _Iter::iterator_category iterator_category;
+};
+
+template <class _Iter, bool> struct __iterator_traits {};
+
+template <class _Iter>
+struct __iterator_traits<_Iter, true>
+    :  __iterator_traits_impl
+      <
+        _Iter,
+        is_convertible<typename _Iter::iterator_category, input_iterator_tag>::value ||
+        is_convertible<typename _Iter::iterator_category, output_iterator_tag>::value
+      >
+{};
+
+// iterator_traits<Iterator> will only have the nested types if Iterator::iterator_category
+//    exists.  Else iterator_traits<Iterator> will be an empty class.  This is a
+//    conforming extension which allows some programs to compile and behave as
+//    the client expects instead of failing at compile time.
+
+template <class _Iter>
+struct _LIBCPP_TYPE_VIS_ONLY iterator_traits
+    : __iterator_traits<_Iter, __has_iterator_category<_Iter>::value> {};
+
+template<class _Tp>
+struct _LIBCPP_TYPE_VIS_ONLY iterator_traits<_Tp*>
+{
+    typedef ptrdiff_t difference_type;
+    typedef typename remove_const<_Tp>::type value_type;
+    typedef _Tp* pointer;
+    typedef _Tp& reference;
+    typedef random_access_iterator_tag iterator_category;
+};
+
+template <class _Tp, class _Up, bool = __has_iterator_category<iterator_traits<_Tp> >::value>
+struct __has_iterator_category_convertible_to
+    : public integral_constant<bool, is_convertible<typename iterator_traits<_Tp>::iterator_category, _Up>::value>
+{};
+
+template <class _Tp, class _Up>
+struct __has_iterator_category_convertible_to<_Tp, _Up, false> : public false_type {};
+
+template <class _Tp>
+struct __is_input_iterator : public __has_iterator_category_convertible_to<_Tp, input_iterator_tag> {};
+
+template <class _Tp>
+struct __is_forward_iterator : public __has_iterator_category_convertible_to<_Tp, forward_iterator_tag> {};
+
+template <class _Tp>
+struct __is_bidirectional_iterator : public __has_iterator_category_convertible_to<_Tp, bidirectional_iterator_tag> {};
+
+template <class _Tp>
+struct __is_random_access_iterator : public __has_iterator_category_convertible_to<_Tp, random_access_iterator_tag> {};
+
+template<class _Category, class _Tp, class _Distance = ptrdiff_t,
+         class _Pointer = _Tp*, class _Reference = _Tp&>
+struct _LIBCPP_TYPE_VIS_ONLY iterator
+{
+    typedef _Tp        value_type;
+    typedef _Distance  difference_type;
+    typedef _Pointer   pointer;
+    typedef _Reference reference;
+    typedef _Category  iterator_category;
+};
+
+template <class _InputIter>
+inline _LIBCPP_INLINE_VISIBILITY
+void __advance(_InputIter& __i,
+             typename iterator_traits<_InputIter>::difference_type __n, input_iterator_tag)
+{
+    for (; __n > 0; --__n)
+        ++__i;
+}
+
+template <class _BiDirIter>
+inline _LIBCPP_INLINE_VISIBILITY
+void __advance(_BiDirIter& __i,
+             typename iterator_traits<_BiDirIter>::difference_type __n, bidirectional_iterator_tag)
+{
+    if (__n >= 0)
+        for (; __n > 0; --__n)
+            ++__i;
+    else
+        for (; __n < 0; ++__n)
+            --__i;
+}
+
+template <class _RandIter>
+inline _LIBCPP_INLINE_VISIBILITY
+void __advance(_RandIter& __i,
+             typename iterator_traits<_RandIter>::difference_type __n, random_access_iterator_tag)
+{
+   __i += __n;
+}
+
+template <class _InputIter>
+inline _LIBCPP_INLINE_VISIBILITY
+void advance(_InputIter& __i,
+             typename iterator_traits<_InputIter>::difference_type __n)
+{
+    __advance(__i, __n, typename iterator_traits<_InputIter>::iterator_category());
+}
+
+template <class _InputIter>
+inline _LIBCPP_INLINE_VISIBILITY
+typename iterator_traits<_InputIter>::difference_type
+__distance(_InputIter __first, _InputIter __last, input_iterator_tag)
+{
+    typename iterator_traits<_InputIter>::difference_type __r(0);
+    for (; __first != __last; ++__first)
+        ++__r;
+    return __r;
+}
+
+template <class _RandIter>
+inline _LIBCPP_INLINE_VISIBILITY
+typename iterator_traits<_RandIter>::difference_type
+__distance(_RandIter __first, _RandIter __last, random_access_iterator_tag)
+{
+    return __last - __first;
+}
+
+template <class _InputIter>
+inline _LIBCPP_INLINE_VISIBILITY
+typename iterator_traits<_InputIter>::difference_type
+distance(_InputIter __first, _InputIter __last)
+{
+    return __distance(__first, __last, typename iterator_traits<_InputIter>::iterator_category());
+}
+
+template <class _ForwardIter>
+inline _LIBCPP_INLINE_VISIBILITY
+_ForwardIter
+next(_ForwardIter __x,
+     typename iterator_traits<_ForwardIter>::difference_type __n = 1,
+     typename enable_if<__is_forward_iterator<_ForwardIter>::value>::type* = 0)
+{
+    _VSTD::advance(__x, __n);
+    return __x;
+}
+
+template <class _BidiretionalIter>
+inline _LIBCPP_INLINE_VISIBILITY
+_BidiretionalIter
+prev(_BidiretionalIter __x,
+     typename iterator_traits<_BidiretionalIter>::difference_type __n = 1,
+     typename enable_if<__is_bidirectional_iterator<_BidiretionalIter>::value>::type* = 0)
+{
+    _VSTD::advance(__x, -__n);
+    return __x;
+}
+
+template <class _Iter>
+class _LIBCPP_TYPE_VIS_ONLY reverse_iterator
+    : public iterator<typename iterator_traits<_Iter>::iterator_category,
+                      typename iterator_traits<_Iter>::value_type,
+                      typename iterator_traits<_Iter>::difference_type,
+                      typename iterator_traits<_Iter>::pointer,
+                      typename iterator_traits<_Iter>::reference>
+{
+private:
+    mutable _Iter __t;  // no longer used as of LWG #2360, not removed due to ABI break
+protected:
+    _Iter current;
+public:
+    typedef _Iter                                            iterator_type;
+    typedef typename iterator_traits<_Iter>::difference_type difference_type;
+    typedef typename iterator_traits<_Iter>::reference       reference;
+    typedef typename iterator_traits<_Iter>::pointer         pointer;
+
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator() : current() {}
+    _LIBCPP_INLINE_VISIBILITY explicit reverse_iterator(_Iter __x) : __t(__x), current(__x) {}
+    template <class _Up> _LIBCPP_INLINE_VISIBILITY reverse_iterator(const reverse_iterator<_Up>& __u)
+        : __t(__u.base()), current(__u.base()) {}
+    _LIBCPP_INLINE_VISIBILITY _Iter base() const {return current;}
+    _LIBCPP_INLINE_VISIBILITY reference operator*() const {_Iter __tmp = current; return *--__tmp;}
+    _LIBCPP_INLINE_VISIBILITY pointer  operator->() const {return _VSTD::addressof(operator*());}
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator& operator++() {--current; return *this;}
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator  operator++(int)
+        {reverse_iterator __tmp(*this); --current; return __tmp;}
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator& operator--() {++current; return *this;}
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator  operator--(int)
+        {reverse_iterator __tmp(*this); ++current; return __tmp;}
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator  operator+ (difference_type __n) const
+        {return reverse_iterator(current - __n);}
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator& operator+=(difference_type __n)
+        {current -= __n; return *this;}
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator  operator- (difference_type __n) const
+        {return reverse_iterator(current + __n);}
+    _LIBCPP_INLINE_VISIBILITY reverse_iterator& operator-=(difference_type __n)
+        {current += __n; return *this;}
+    _LIBCPP_INLINE_VISIBILITY reference         operator[](difference_type __n) const
+        {return *(*this + __n);}
+};
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
+{
+    return __x.base() == __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
+{
+    return __x.base() > __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
+{
+    return __x.base() != __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
+{
+    return __x.base() < __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
+{
+    return __x.base() <= __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
+{
+    return __x.base() >= __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename reverse_iterator<_Iter1>::difference_type
+operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
+{
+    return __y.base() - __x.base();
+}
+
+template <class _Iter>
+inline _LIBCPP_INLINE_VISIBILITY
+reverse_iterator<_Iter>
+operator+(typename reverse_iterator<_Iter>::difference_type __n, const reverse_iterator<_Iter>& __x)
+{
+    return reverse_iterator<_Iter>(__x.base() - __n);
+}
+
+#if _LIBCPP_STD_VER > 11
+template <class _Iter>
+inline _LIBCPP_INLINE_VISIBILITY
+reverse_iterator<_Iter> make_reverse_iterator(_Iter __i)
+{
+    return reverse_iterator<_Iter>(__i);
+}
+#endif
+
+template <class _Container>
+class _LIBCPP_TYPE_VIS_ONLY back_insert_iterator
+    : public iterator<output_iterator_tag,
+                      void,
+                      void,
+                      void,
+                      back_insert_iterator<_Container>&>
+{
+protected:
+    _Container* container;
+public:
+    typedef _Container container_type;
+
+    _LIBCPP_INLINE_VISIBILITY explicit back_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
+    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator=(const typename _Container::value_type& __value_)
+        {container->push_back(__value_); return *this;}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator=(typename _Container::value_type&& __value_)
+        {container->push_back(_VSTD::move(__value_)); return *this;}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator*()     {return *this;}
+    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator++()    {return *this;}
+    _LIBCPP_INLINE_VISIBILITY back_insert_iterator  operator++(int) {return *this;}
+};
+
+template <class _Container>
+inline _LIBCPP_INLINE_VISIBILITY
+back_insert_iterator<_Container>
+back_inserter(_Container& __x)
+{
+    return back_insert_iterator<_Container>(__x);
+}
+
+template <class _Container>
+class _LIBCPP_TYPE_VIS_ONLY front_insert_iterator
+    : public iterator<output_iterator_tag,
+                      void,
+                      void,
+                      void,
+                      front_insert_iterator<_Container>&>
+{
+protected:
+    _Container* container;
+public:
+    typedef _Container container_type;
+
+    _LIBCPP_INLINE_VISIBILITY explicit front_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
+    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator=(const typename _Container::value_type& __value_)
+        {container->push_front(__value_); return *this;}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator=(typename _Container::value_type&& __value_)
+        {container->push_front(_VSTD::move(__value_)); return *this;}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator*()     {return *this;}
+    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator++()    {return *this;}
+    _LIBCPP_INLINE_VISIBILITY front_insert_iterator  operator++(int) {return *this;}
+};
+
+template <class _Container>
+inline _LIBCPP_INLINE_VISIBILITY
+front_insert_iterator<_Container>
+front_inserter(_Container& __x)
+{
+    return front_insert_iterator<_Container>(__x);
+}
+
+template <class _Container>
+class _LIBCPP_TYPE_VIS_ONLY insert_iterator
+    : public iterator<output_iterator_tag,
+                      void,
+                      void,
+                      void,
+                      insert_iterator<_Container>&>
+{
+protected:
+    _Container* container;
+    typename _Container::iterator iter;
+public:
+    typedef _Container container_type;
+
+    _LIBCPP_INLINE_VISIBILITY insert_iterator(_Container& __x, typename _Container::iterator __i)
+        : container(_VSTD::addressof(__x)), iter(__i) {}
+    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator=(const typename _Container::value_type& __value_)
+        {iter = container->insert(iter, __value_); ++iter; return *this;}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator=(typename _Container::value_type&& __value_)
+        {iter = container->insert(iter, _VSTD::move(__value_)); ++iter; return *this;}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator*()        {return *this;}
+    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator++()       {return *this;}
+    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator++(int)    {return *this;}
+};
+
+template <class _Container>
+inline _LIBCPP_INLINE_VISIBILITY
+insert_iterator<_Container>
+inserter(_Container& __x, typename _Container::iterator __i)
+{
+    return insert_iterator<_Container>(__x, __i);
+}
+
+template <class _Tp, class _CharT = char,
+          class _Traits = char_traits<_CharT>, class _Distance = ptrdiff_t>
+class _LIBCPP_TYPE_VIS_ONLY istream_iterator
+    : public iterator<input_iterator_tag, _Tp, _Distance, const _Tp*, const _Tp&>
+{
+public:
+    typedef _CharT char_type;
+    typedef _Traits traits_type;
+    typedef basic_istream<_CharT,_Traits> istream_type;
+private:
+    istream_type* __in_stream_;
+    _Tp __value_;
+public:
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istream_iterator() : __in_stream_(0), __value_() {}
+    _LIBCPP_INLINE_VISIBILITY istream_iterator(istream_type& __s) : __in_stream_(&__s)
+        {
+            if (!(*__in_stream_ >> __value_))
+                __in_stream_ = 0;
+        }
+
+    _LIBCPP_INLINE_VISIBILITY const _Tp& operator*() const {return __value_;}
+    _LIBCPP_INLINE_VISIBILITY const _Tp* operator->() const {return &(operator*());}
+    _LIBCPP_INLINE_VISIBILITY istream_iterator& operator++()
+        {
+            if (!(*__in_stream_ >> __value_))
+                __in_stream_ = 0;
+            return *this;
+        }
+    _LIBCPP_INLINE_VISIBILITY istream_iterator  operator++(int)
+        {istream_iterator __t(*this); ++(*this); return __t;}
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator==(const istream_iterator& __x, const istream_iterator& __y)
+        {return __x.__in_stream_ == __y.__in_stream_;}
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(const istream_iterator& __x, const istream_iterator& __y)
+        {return !(__x == __y);}
+};
+
+template <class _Tp, class _CharT = char, class _Traits = char_traits<_CharT> >
+class _LIBCPP_TYPE_VIS_ONLY ostream_iterator
+    : public iterator<output_iterator_tag, void, void, void, void>
+{
+public:
+    typedef _CharT char_type;
+    typedef _Traits traits_type;
+    typedef basic_ostream<_CharT,_Traits> ostream_type;
+private:
+    ostream_type* __out_stream_;
+    const char_type* __delim_;
+public:
+    _LIBCPP_INLINE_VISIBILITY ostream_iterator(ostream_type& __s)
+        : __out_stream_(&__s), __delim_(0) {}
+    _LIBCPP_INLINE_VISIBILITY ostream_iterator(ostream_type& __s, const _CharT* __delimiter)
+        : __out_stream_(&__s), __delim_(__delimiter) {}
+    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator=(const _Tp& __value_)
+        {
+            *__out_stream_ << __value_;
+            if (__delim_)
+                *__out_stream_ << __delim_;
+            return *this;
+        }
+
+    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator*()     {return *this;}
+    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator++()    {return *this;}
+    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator++(int) {return *this;}
+};
+
+template<class _CharT, class _Traits>
+class _LIBCPP_TYPE_VIS_ONLY istreambuf_iterator
+    : public iterator<input_iterator_tag, _CharT,
+                      typename _Traits::off_type, _CharT*,
+                      _CharT>
+{
+public:
+    typedef _CharT                          char_type;
+    typedef _Traits                         traits_type;
+    typedef typename _Traits::int_type      int_type;
+    typedef basic_streambuf<_CharT,_Traits> streambuf_type;
+    typedef basic_istream<_CharT,_Traits>   istream_type;
+private:
+    mutable streambuf_type* __sbuf_;
+
+    class __proxy
+    {
+        char_type __keep_;
+        streambuf_type* __sbuf_;
+        _LIBCPP_INLINE_VISIBILITY __proxy(char_type __c, streambuf_type* __s)
+            : __keep_(__c), __sbuf_(__s) {}
+        friend class istreambuf_iterator;
+    public:
+        _LIBCPP_INLINE_VISIBILITY char_type operator*() const {return __keep_;}
+    };
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool __test_for_eof() const
+    {
+        if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sgetc(), traits_type::eof()))
+            __sbuf_ = 0;
+        return __sbuf_ == 0;
+    }
+public:
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istreambuf_iterator() _NOEXCEPT : __sbuf_(0) {}
+    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(istream_type& __s) _NOEXCEPT
+        : __sbuf_(__s.rdbuf()) {}
+    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(streambuf_type* __s) _NOEXCEPT
+        : __sbuf_(__s) {}
+    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(const __proxy& __p) _NOEXCEPT
+        : __sbuf_(__p.__sbuf_) {}
+
+    _LIBCPP_INLINE_VISIBILITY char_type  operator*() const
+        {return static_cast<char_type>(__sbuf_->sgetc());}
+    _LIBCPP_INLINE_VISIBILITY char_type* operator->() const {return nullptr;}
+    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator& operator++()
+        {
+            __sbuf_->sbumpc();
+            return *this;
+        }
+    _LIBCPP_INLINE_VISIBILITY __proxy              operator++(int)
+        {
+            return __proxy(__sbuf_->sbumpc(), __sbuf_);
+        }
+
+    _LIBCPP_INLINE_VISIBILITY bool equal(const istreambuf_iterator& __b) const
+        {return __test_for_eof() == __b.__test_for_eof();}
+};
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+bool operator==(const istreambuf_iterator<_CharT,_Traits>& __a,
+                const istreambuf_iterator<_CharT,_Traits>& __b)
+                {return __a.equal(__b);}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+bool operator!=(const istreambuf_iterator<_CharT,_Traits>& __a,
+                const istreambuf_iterator<_CharT,_Traits>& __b)
+                {return !__a.equal(__b);}
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TYPE_VIS_ONLY ostreambuf_iterator
+    : public iterator<output_iterator_tag, void, void, void, void>
+{
+public:
+    typedef _CharT                          char_type;
+    typedef _Traits                         traits_type;
+    typedef basic_streambuf<_CharT,_Traits> streambuf_type;
+    typedef basic_ostream<_CharT,_Traits>   ostream_type;
+private:
+    streambuf_type* __sbuf_;
+public:
+    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator(ostream_type& __s) _NOEXCEPT
+        : __sbuf_(__s.rdbuf()) {}
+    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator(streambuf_type* __s) _NOEXCEPT
+        : __sbuf_(__s) {}
+    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator=(_CharT __c)
+        {
+            if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sputc(__c), traits_type::eof()))
+                __sbuf_ = 0;
+            return *this;
+        }
+    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator*()     {return *this;}
+    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator++()    {return *this;}
+    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator++(int) {return *this;}
+    _LIBCPP_INLINE_VISIBILITY bool failed() const _NOEXCEPT {return __sbuf_ == 0;}
+
+#if !defined(__APPLE__) || \
+    (defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && __MAC_OS_X_VERSION_MIN_REQUIRED > __MAC_10_8) || \
+    (defined(__IPHONE_OS_VERSION_MIN_REQUIRED) && __IPHONE_OS_VERSION_MIN_REQUIRED > __IPHONE_6_0)
+
+    template <class _Ch, class _Tr>
+    friend
+    _LIBCPP_HIDDEN
+    ostreambuf_iterator<_Ch, _Tr>
+    __pad_and_output(ostreambuf_iterator<_Ch, _Tr> __s,
+                     const _Ch* __ob, const _Ch* __op, const _Ch* __oe,
+                     ios_base& __iob, _Ch __fl);
+#endif
+};
+
+template <class _Iter>
+class _LIBCPP_TYPE_VIS_ONLY move_iterator
+{
+private:
+    _Iter __i;
+public:
+    typedef _Iter                                            iterator_type;
+    typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
+    typedef typename iterator_traits<iterator_type>::value_type value_type;
+    typedef typename iterator_traits<iterator_type>::difference_type difference_type;
+    typedef typename iterator_traits<iterator_type>::pointer pointer;
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    typedef value_type&& reference;
+#else
+    typedef typename iterator_traits<iterator_type>::reference reference;
+#endif
+
+    _LIBCPP_INLINE_VISIBILITY move_iterator() : __i() {}
+    _LIBCPP_INLINE_VISIBILITY explicit move_iterator(_Iter __x) : __i(__x) {}
+    template <class _Up> _LIBCPP_INLINE_VISIBILITY move_iterator(const move_iterator<_Up>& __u)
+        : __i(__u.base()) {}
+    _LIBCPP_INLINE_VISIBILITY _Iter base() const {return __i;}
+    _LIBCPP_INLINE_VISIBILITY reference operator*() const {
+      return static_cast<reference>(*__i);
+    }
+    _LIBCPP_INLINE_VISIBILITY pointer  operator->() const {
+      typename iterator_traits<iterator_type>::reference __ref = *__i;
+      return &__ref;
+    }
+    _LIBCPP_INLINE_VISIBILITY move_iterator& operator++() {++__i; return *this;}
+    _LIBCPP_INLINE_VISIBILITY move_iterator  operator++(int)
+        {move_iterator __tmp(*this); ++__i; return __tmp;}
+    _LIBCPP_INLINE_VISIBILITY move_iterator& operator--() {--__i; return *this;}
+    _LIBCPP_INLINE_VISIBILITY move_iterator  operator--(int)
+        {move_iterator __tmp(*this); --__i; return __tmp;}
+    _LIBCPP_INLINE_VISIBILITY move_iterator  operator+ (difference_type __n) const
+        {return move_iterator(__i + __n);}
+    _LIBCPP_INLINE_VISIBILITY move_iterator& operator+=(difference_type __n)
+        {__i += __n; return *this;}
+    _LIBCPP_INLINE_VISIBILITY move_iterator  operator- (difference_type __n) const
+        {return move_iterator(__i - __n);}
+    _LIBCPP_INLINE_VISIBILITY move_iterator& operator-=(difference_type __n)
+        {__i -= __n; return *this;}
+    _LIBCPP_INLINE_VISIBILITY reference         operator[](difference_type __n) const
+    {
+      return static_cast<reference>(__i[__n]);
+    }
+};
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
+{
+    return __x.base() == __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
+{
+    return __x.base() < __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
+{
+    return __x.base() != __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
+{
+    return __x.base() > __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
+{
+    return __x.base() >= __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
+{
+    return __x.base() <= __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename move_iterator<_Iter1>::difference_type
+operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
+{
+    return __x.base() - __y.base();
+}
+
+template <class _Iter>
+inline _LIBCPP_INLINE_VISIBILITY
+move_iterator<_Iter>
+operator+(typename move_iterator<_Iter>::difference_type __n, const move_iterator<_Iter>& __x)
+{
+    return move_iterator<_Iter>(__x.base() + __n);
+}
+
+template <class _Iter>
+inline _LIBCPP_INLINE_VISIBILITY
+move_iterator<_Iter>
+make_move_iterator(_Iter __i)
+{
+    return move_iterator<_Iter>(__i);
+}
+
+// __wrap_iter
+
+template <class _Iter> class __wrap_iter;
+
+template <class _Iter1, class _Iter2>
+_LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+template <class _Iter1, class _Iter2>
+_LIBCPP_INLINE_VISIBILITY
+bool
+operator<(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+template <class _Iter1, class _Iter2>
+_LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+template <class _Iter1, class _Iter2>
+_LIBCPP_INLINE_VISIBILITY
+bool
+operator>(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+template <class _Iter1, class _Iter2>
+_LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+template <class _Iter1, class _Iter2>
+_LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+template <class _Iter1, class _Iter2>
+_LIBCPP_INLINE_VISIBILITY
+typename __wrap_iter<_Iter1>::difference_type
+operator-(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+template <class _Iter>
+_LIBCPP_INLINE_VISIBILITY
+__wrap_iter<_Iter>
+operator+(typename __wrap_iter<_Iter>::difference_type, __wrap_iter<_Iter>) _NOEXCEPT;
+
+template <class _Ip, class _Op> _Op _LIBCPP_INLINE_VISIBILITY copy(_Ip, _Ip, _Op);
+template <class _B1, class _B2> _B2 _LIBCPP_INLINE_VISIBILITY copy_backward(_B1, _B1, _B2);
+template <class _Ip, class _Op> _Op _LIBCPP_INLINE_VISIBILITY move(_Ip, _Ip, _Op);
+template <class _B1, class _B2> _B2 _LIBCPP_INLINE_VISIBILITY move_backward(_B1, _B1, _B2);
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_trivially_copy_assignable<_Tp>::value,
+    _Tp*
+>::type
+__unwrap_iter(__wrap_iter<_Tp*>);
+
+template <class _Tp, class _Alloc> class _LIBCPP_TYPE_VIS_ONLY vector;
+
+template <class _Iter>
+class __wrap_iter
+{
+public:
+    typedef _Iter                                                      iterator_type;
+    typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
+    typedef typename iterator_traits<iterator_type>::value_type        value_type;
+    typedef typename iterator_traits<iterator_type>::difference_type   difference_type;
+    typedef typename iterator_traits<iterator_type>::pointer           pointer;
+    typedef typename iterator_traits<iterator_type>::reference         reference;
+private:
+    iterator_type __i;
+public:
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter() _NOEXCEPT
+#if _LIBCPP_STD_VER > 11
+                : __i{}
+#endif
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __get_db()->__insert_i(this);
+#endif
+    }
+    template <class _Up> _LIBCPP_INLINE_VISIBILITY __wrap_iter(const __wrap_iter<_Up>& __u,
+        typename enable_if<is_convertible<_Up, iterator_type>::value>::type* = 0) _NOEXCEPT
+        : __i(__u.base())
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __get_db()->__iterator_copy(this, &__u);
+#endif
+    }
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_INLINE_VISIBILITY
+    __wrap_iter(const __wrap_iter& __x)
+        : __i(__x.base())
+    {
+        __get_db()->__iterator_copy(this, &__x);
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    __wrap_iter& operator=(const __wrap_iter& __x)
+    {
+        if (this != &__x)
+        {
+            __get_db()->__iterator_copy(this, &__x);
+            __i = __x.__i;
+        }
+        return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    ~__wrap_iter()
+    {
+        __get_db()->__erase_i(this);
+    }
+#endif
+    _LIBCPP_INLINE_VISIBILITY reference operator*() const _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                       "Attempted to dereference a non-dereferenceable iterator");
+#endif
+        return *__i;
+    }
+    _LIBCPP_INLINE_VISIBILITY pointer  operator->() const _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                       "Attempted to dereference a non-dereferenceable iterator");
+#endif
+        return (pointer)&reinterpret_cast<const volatile char&>(*__i);
+    }
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter& operator++() _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                       "Attempted to increment non-incrementable iterator");
+#endif
+        ++__i;
+        return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter  operator++(int) _NOEXCEPT
+        {__wrap_iter __tmp(*this); ++(*this); return __tmp;}
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter& operator--() _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__decrementable(this),
+                       "Attempted to decrement non-decrementable iterator");
+#endif
+        --__i;
+        return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter  operator--(int) _NOEXCEPT
+        {__wrap_iter __tmp(*this); --(*this); return __tmp;}
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter  operator+ (difference_type __n) const _NOEXCEPT
+        {__wrap_iter __w(*this); __w += __n; return __w;}
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter& operator+=(difference_type __n) _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__addable(this, __n),
+                   "Attempted to add/subtract iterator outside of valid range");
+#endif
+        __i += __n;
+        return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter  operator- (difference_type __n) const _NOEXCEPT
+        {return *this + (-__n);}
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter& operator-=(difference_type __n) _NOEXCEPT
+        {*this += -__n; return *this;}
+    _LIBCPP_INLINE_VISIBILITY reference        operator[](difference_type __n) const _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__subscriptable(this, __n),
+                   "Attempted to subscript iterator outside of valid range");
+#endif
+        return __i[__n];
+    }
+
+    _LIBCPP_INLINE_VISIBILITY iterator_type base() const _NOEXCEPT {return __i;}
+
+private:
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter(const void* __p, iterator_type __x) : __i(__x)
+    {
+        __get_db()->__insert_ic(this, __p);
+    }
+#else
+    _LIBCPP_INLINE_VISIBILITY __wrap_iter(iterator_type __x) _NOEXCEPT : __i(__x) {}
+#endif
+
+    template <class _Up> friend class __wrap_iter;
+    template <class _CharT, class _Traits, class _Alloc> friend class basic_string;
+    template <class _Tp, class _Alloc> friend class vector;
+
+    template <class _Iter1, class _Iter2>
+    friend
+    bool
+    operator==(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+    template <class _Iter1, class _Iter2>
+    friend
+    bool
+    operator<(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+    template <class _Iter1, class _Iter2>
+    friend
+    bool
+    operator!=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+    template <class _Iter1, class _Iter2>
+    friend
+    bool
+    operator>(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+    template <class _Iter1, class _Iter2>
+    friend
+    bool
+    operator>=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+    template <class _Iter1, class _Iter2>
+    friend
+    bool
+    operator<=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+    template <class _Iter1, class _Iter2>
+    friend
+    typename __wrap_iter<_Iter1>::difference_type
+    operator-(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT;
+
+    template <class _Iter1>
+    friend
+    __wrap_iter<_Iter1>
+    operator+(typename __wrap_iter<_Iter1>::difference_type, __wrap_iter<_Iter1>) _NOEXCEPT;
+
+    template <class _Ip, class _Op> friend _Op copy(_Ip, _Ip, _Op);
+    template <class _B1, class _B2> friend _B2 copy_backward(_B1, _B1, _B2);
+    template <class _Ip, class _Op> friend _Op move(_Ip, _Ip, _Op);
+    template <class _B1, class _B2> friend _B2 move_backward(_B1, _B1, _B2);
+
+    template <class _Tp>
+    friend
+    typename enable_if
+    <
+        is_trivially_copy_assignable<_Tp>::value,
+        _Tp*
+    >::type
+    __unwrap_iter(__wrap_iter<_Tp*>);
+};
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
+{
+    return __x.base() == __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
+                   "Attempted to compare incomparable iterators");
+#endif
+    return __x.base() < __y.base();
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
+{
+    return !(__x == __y);
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
+{
+    return __y < __x;
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
+{
+    return !(__x < __y);
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
+{
+    return !(__y < __x);
+}
+
+template <class _Iter1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
+{
+    return !(__x == __y);
+}
+
+template <class _Iter1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
+{
+    return __y < __x;
+}
+
+template <class _Iter1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
+{
+    return !(__x < __y);
+}
+
+template <class _Iter1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT
+{
+    return !(__y < __x);
+}
+
+template <class _Iter1, class _Iter2>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __wrap_iter<_Iter1>::difference_type
+operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
+                   "Attempted to subtract incompatible iterators");
+#endif
+    return __x.base() - __y.base();
+}
+
+template <class _Iter>
+inline _LIBCPP_INLINE_VISIBILITY
+__wrap_iter<_Iter>
+operator+(typename __wrap_iter<_Iter>::difference_type __n,
+          __wrap_iter<_Iter> __x) _NOEXCEPT
+{
+    __x += __n;
+    return __x;
+}
+
+template <class _Tp, size_t _Np>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_Tp*
+begin(_Tp (&__array)[_Np])
+{
+    return __array;
+}
+
+template <class _Tp, size_t _Np>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+_Tp*
+end(_Tp (&__array)[_Np])
+{
+    return __array + _Np;
+}
+
+#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_TRAILING_RETURN)
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto
+begin(_Cp& __c) -> decltype(__c.begin())
+{
+    return __c.begin();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto
+begin(const _Cp& __c) -> decltype(__c.begin())
+{
+    return __c.begin();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto
+end(_Cp& __c) -> decltype(__c.end())
+{
+    return __c.end();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto
+end(const _Cp& __c) -> decltype(__c.end())
+{
+    return __c.end();
+}
+
+#if _LIBCPP_STD_VER > 11
+
+template <class _Tp, size_t _Np>
+inline _LIBCPP_INLINE_VISIBILITY
+reverse_iterator<_Tp*> rbegin(_Tp (&__array)[_Np])
+{
+    return reverse_iterator<_Tp*>(__array + _Np);
+}
+
+template <class _Tp, size_t _Np>
+inline _LIBCPP_INLINE_VISIBILITY
+reverse_iterator<_Tp*> rend(_Tp (&__array)[_Np])
+{
+    return reverse_iterator<_Tp*>(__array);
+}
+
+template <class _Ep>
+inline _LIBCPP_INLINE_VISIBILITY
+reverse_iterator<const _Ep*> rbegin(initializer_list<_Ep> __il)
+{
+    return reverse_iterator<const _Ep*>(__il.end());
+}
+
+template <class _Ep>
+inline _LIBCPP_INLINE_VISIBILITY
+reverse_iterator<const _Ep*> rend(initializer_list<_Ep> __il)
+{
+    return reverse_iterator<const _Ep*>(__il.begin());
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+auto cbegin(const _Cp& __c) -> decltype(begin(__c))
+{
+    return begin(__c);
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+auto cend(const _Cp& __c) -> decltype(end(__c))
+{
+    return end(__c);
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto rbegin(_Cp& __c) -> decltype(__c.rbegin())
+{
+    return __c.rbegin();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto rbegin(const _Cp& __c) -> decltype(__c.rbegin())
+{
+    return __c.rbegin();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto rend(_Cp& __c) -> decltype(__c.rend())
+{
+    return __c.rend();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto rend(const _Cp& __c) -> decltype(__c.rend())
+{
+    return __c.rend();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto crbegin(const _Cp& __c) -> decltype(rbegin(__c))
+{
+    return rbegin(__c);
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+auto crend(const _Cp& __c) -> decltype(rend(__c))
+{
+    return rend(__c);
+}
+
+#endif
+
+
+#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_TRAILING_RETURN)
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename _Cp::iterator
+begin(_Cp& __c)
+{
+    return __c.begin();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename _Cp::const_iterator
+begin(const _Cp& __c)
+{
+    return __c.begin();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename _Cp::iterator
+end(_Cp& __c)
+{
+    return __c.end();
+}
+
+template <class _Cp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename _Cp::const_iterator
+end(const _Cp& __c)
+{
+    return __c.end();
+}
+
+#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_TRAILING_RETURN)
+
+#if _LIBCPP_STD_VER > 14
+template <class _Cont>
+constexpr auto size(const _Cont& __c) -> decltype(__c.size()) { return __c.size(); }
+
+template <class _Tp, size_t _Sz>
+constexpr size_t size(const _Tp (&__array)[_Sz]) noexcept { return _Sz; }
+
+template <class _Cont>
+constexpr auto empty(const _Cont& __c) -> decltype(__c.empty()) { return __c.empty(); }
+
+template <class _Tp, size_t _Sz>
+constexpr bool empty(const _Tp (&__array)[_Sz]) noexcept { return false; }
+
+template <class _Ep>
+constexpr bool empty(initializer_list<_Ep> __il) noexcept { return __il.size() == 0; }
+
+template <class _Cont> constexpr
+auto data(_Cont& __c) -> decltype(__c.data()) { return __c.data(); }
+
+template <class _Cont> constexpr
+auto data(const _Cont& __c) -> decltype(__c.data()) { return __c.data(); }
+
+template <class _Tp, size_t _Sz>
+constexpr _Tp* data(_Tp (&__array)[_Sz]) noexcept { return __array; }
+
+template <class _Ep>
+constexpr const _Ep* data(initializer_list<_Ep> __il) noexcept { return __il.begin(); }
+#endif
+
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_ITERATOR

diff --git a/libcxx/include/limits b/libcxx/include/limits
new file mode 100644
index 0000000..ce967ea
--- /dev/null
+++ b/libcxx/include/limits

@@ -0,0 +1,813 @@
+// -*- C++ -*-
+//===---------------------------- limits ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_LIMITS
+#define _LIBCPP_LIMITS
+
+/*
+    limits synopsis
+
+namespace std
+{
+
+template<class T>
+class numeric_limits
+{
+public:
+    static constexpr bool is_specialized = false;
+    static constexpr T min() noexcept;
+    static constexpr T max() noexcept;
+    static constexpr T lowest() noexcept;
+
+    static constexpr int  digits = 0;
+    static constexpr int  digits10 = 0;
+    static constexpr int  max_digits10 = 0;
+    static constexpr bool is_signed = false;
+    static constexpr bool is_integer = false;
+    static constexpr bool is_exact = false;
+    static constexpr int  radix = 0;
+    static constexpr T epsilon() noexcept;
+    static constexpr T round_error() noexcept;
+
+    static constexpr int  min_exponent = 0;
+    static constexpr int  min_exponent10 = 0;
+    static constexpr int  max_exponent = 0;
+    static constexpr int  max_exponent10 = 0;
+
+    static constexpr bool has_infinity = false;
+    static constexpr bool has_quiet_NaN = false;
+    static constexpr bool has_signaling_NaN = false;
+    static constexpr float_denorm_style has_denorm = denorm_absent;
+    static constexpr bool has_denorm_loss = false;
+    static constexpr T infinity() noexcept;
+    static constexpr T quiet_NaN() noexcept;
+    static constexpr T signaling_NaN() noexcept;
+    static constexpr T denorm_min() noexcept;
+
+    static constexpr bool is_iec559 = false;
+    static constexpr bool is_bounded = false;
+    static constexpr bool is_modulo = false;
+
+    static constexpr bool traps = false;
+    static constexpr bool tinyness_before = false;
+    static constexpr float_round_style round_style = round_toward_zero;
+};
+
+enum float_round_style
+{
+    round_indeterminate       = -1,
+    round_toward_zero         =  0,
+    round_to_nearest          =  1,
+    round_toward_infinity     =  2,
+    round_toward_neg_infinity =  3
+};
+
+enum float_denorm_style
+{
+    denorm_indeterminate = -1,
+    denorm_absent = 0,
+    denorm_present = 1
+};
+
+template<> class numeric_limits<cv bool>;
+
+template<> class numeric_limits<cv char>;
+template<> class numeric_limits<cv signed char>;
+template<> class numeric_limits<cv unsigned char>;
+template<> class numeric_limits<cv wchar_t>;
+template<> class numeric_limits<cv char16_t>;
+template<> class numeric_limits<cv char32_t>;
+
+template<> class numeric_limits<cv short>;
+template<> class numeric_limits<cv int>;
+template<> class numeric_limits<cv long>;
+template<> class numeric_limits<cv long long>;
+template<> class numeric_limits<cv unsigned short>;
+template<> class numeric_limits<cv unsigned int>;
+template<> class numeric_limits<cv unsigned long>;
+template<> class numeric_limits<cv unsigned long long>;
+
+template<> class numeric_limits<cv float>;
+template<> class numeric_limits<cv double>;
+template<> class numeric_limits<cv long double>;
+
+}  // std
+
+*/
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+#include <__config>
+#include <type_traits>
+
+#include <__undef_min_max>
+
+#if defined(_LIBCPP_MSVCRT)
+#include "support/win32/limits_win32.h"
+#endif // _LIBCPP_MSVCRT
+
+#if defined(__IBMCPP__)
+#include "support/ibm/limits.h"
+#endif // __IBMCPP__
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+enum float_round_style
+{
+    round_indeterminate       = -1,
+    round_toward_zero         =  0,
+    round_to_nearest          =  1,
+    round_toward_infinity     =  2,
+    round_toward_neg_infinity =  3
+};
+
+enum float_denorm_style
+{
+    denorm_indeterminate = -1,
+    denorm_absent = 0,
+    denorm_present = 1
+};
+
+template <class _Tp, bool = is_arithmetic<_Tp>::value>
+class __libcpp_numeric_limits
+{
+protected:
+    typedef _Tp type;
+
+    static _LIBCPP_CONSTEXPR const  bool is_specialized = false;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return type();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return type();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return type();}
+
+    static _LIBCPP_CONSTEXPR const int  digits = 0;
+    static _LIBCPP_CONSTEXPR const int  digits10 = 0;
+    static _LIBCPP_CONSTEXPR const int  max_digits10 = 0;
+    static _LIBCPP_CONSTEXPR const bool is_signed = false;
+    static _LIBCPP_CONSTEXPR const bool is_integer = false;
+    static _LIBCPP_CONSTEXPR const bool is_exact = false;
+    static _LIBCPP_CONSTEXPR const int  radix = 0;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return type();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return type();}
+
+    static _LIBCPP_CONSTEXPR const int  min_exponent = 0;
+    static _LIBCPP_CONSTEXPR const int  min_exponent10 = 0;
+    static _LIBCPP_CONSTEXPR const int  max_exponent = 0;
+    static _LIBCPP_CONSTEXPR const int  max_exponent10 = 0;
+
+    static _LIBCPP_CONSTEXPR const bool has_infinity = false;
+    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = false;
+    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = false;
+    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = denorm_absent;
+    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = false;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return type();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return type();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return type();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return type();}
+
+    static _LIBCPP_CONSTEXPR const bool is_iec559 = false;
+    static _LIBCPP_CONSTEXPR const bool is_bounded = false;
+    static _LIBCPP_CONSTEXPR const bool is_modulo = false;
+
+    static _LIBCPP_CONSTEXPR const bool traps = false;
+    static _LIBCPP_CONSTEXPR const bool tinyness_before = false;
+    static _LIBCPP_CONSTEXPR const float_round_style round_style = round_toward_zero;
+};
+
+template <class _Tp, int digits, bool is_signed>
+struct __libcpp_compute_min
+{
+    static _LIBCPP_CONSTEXPR const _Tp value = _Tp(_Tp(1) << digits);
+};
+
+template <class _Tp, int digits>
+struct __libcpp_compute_min<_Tp, digits, false>
+{
+    static _LIBCPP_CONSTEXPR const _Tp value = _Tp(0);
+};
+
+template <class _Tp>
+class __libcpp_numeric_limits<_Tp, true>
+{
+protected:
+    typedef _Tp type;
+
+    static _LIBCPP_CONSTEXPR const bool is_specialized = true;
+
+    static _LIBCPP_CONSTEXPR const bool is_signed = type(-1) < type(0);
+    static _LIBCPP_CONSTEXPR const int  digits = static_cast<int>(sizeof(type) * __CHAR_BIT__ - is_signed);
+    static _LIBCPP_CONSTEXPR const int  digits10 = digits * 3 / 10;
+    static _LIBCPP_CONSTEXPR const int  max_digits10 = 0;
+    static _LIBCPP_CONSTEXPR const type __min = __libcpp_compute_min<type, digits, is_signed>::value;
+    static _LIBCPP_CONSTEXPR const type __max = is_signed ? type(type(~0) ^ __min) : type(~0);
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __min;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __max;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return min();}
+
+    static _LIBCPP_CONSTEXPR const bool is_integer = true;
+    static _LIBCPP_CONSTEXPR const bool is_exact = true;
+    static _LIBCPP_CONSTEXPR const int  radix = 2;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return type(0);}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return type(0);}
+
+    static _LIBCPP_CONSTEXPR const int  min_exponent = 0;
+    static _LIBCPP_CONSTEXPR const int  min_exponent10 = 0;
+    static _LIBCPP_CONSTEXPR const int  max_exponent = 0;
+    static _LIBCPP_CONSTEXPR const int  max_exponent10 = 0;
+
+    static _LIBCPP_CONSTEXPR const bool has_infinity = false;
+    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = false;
+    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = false;
+    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = denorm_absent;
+    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = false;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return type(0);}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return type(0);}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return type(0);}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return type(0);}
+
+    static _LIBCPP_CONSTEXPR const bool is_iec559 = false;
+    static _LIBCPP_CONSTEXPR const bool is_bounded = true;
+    static _LIBCPP_CONSTEXPR const bool is_modulo = !_VSTD::is_signed<_Tp>::value;
+
+#if defined(__i386__) || defined(__x86_64__) || defined(__pnacl__)
+    static _LIBCPP_CONSTEXPR const bool traps = true;
+#else
+    static _LIBCPP_CONSTEXPR const bool traps = false;
+#endif
+    static _LIBCPP_CONSTEXPR const bool tinyness_before = false;
+    static _LIBCPP_CONSTEXPR const float_round_style round_style = round_toward_zero;
+};
+
+template <>
+class __libcpp_numeric_limits<bool, true>
+{
+protected:
+    typedef bool type;
+
+    static _LIBCPP_CONSTEXPR const bool is_specialized = true;
+
+    static _LIBCPP_CONSTEXPR const bool is_signed = false;
+    static _LIBCPP_CONSTEXPR const int  digits = 1;
+    static _LIBCPP_CONSTEXPR const int  digits10 = 0;
+    static _LIBCPP_CONSTEXPR const int  max_digits10 = 0;
+    static _LIBCPP_CONSTEXPR const type __min = false;
+    static _LIBCPP_CONSTEXPR const type __max = true;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __min;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __max;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return min();}
+
+    static _LIBCPP_CONSTEXPR const bool is_integer = true;
+    static _LIBCPP_CONSTEXPR const bool is_exact = true;
+    static _LIBCPP_CONSTEXPR const int  radix = 2;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return type(0);}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return type(0);}
+
+    static _LIBCPP_CONSTEXPR const int  min_exponent = 0;
+    static _LIBCPP_CONSTEXPR const int  min_exponent10 = 0;
+    static _LIBCPP_CONSTEXPR const int  max_exponent = 0;
+    static _LIBCPP_CONSTEXPR const int  max_exponent10 = 0;
+
+    static _LIBCPP_CONSTEXPR const bool has_infinity = false;
+    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = false;
+    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = false;
+    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = denorm_absent;
+    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = false;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return type(0);}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return type(0);}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return type(0);}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return type(0);}
+
+    static _LIBCPP_CONSTEXPR const bool is_iec559 = false;
+    static _LIBCPP_CONSTEXPR const bool is_bounded = true;
+    static _LIBCPP_CONSTEXPR const bool is_modulo = false;
+
+    static _LIBCPP_CONSTEXPR const bool traps = false;
+    static _LIBCPP_CONSTEXPR const bool tinyness_before = false;
+    static _LIBCPP_CONSTEXPR const float_round_style round_style = round_toward_zero;
+};
+
+template <>
+class __libcpp_numeric_limits<float, true>
+{
+protected:
+    typedef float type;
+
+    static _LIBCPP_CONSTEXPR const bool is_specialized = true;
+
+    static _LIBCPP_CONSTEXPR const bool is_signed = true;
+    static _LIBCPP_CONSTEXPR const int  digits = __FLT_MANT_DIG__;
+    static _LIBCPP_CONSTEXPR const int  digits10 = __FLT_DIG__;
+    static _LIBCPP_CONSTEXPR const int  max_digits10 = 2+(digits * 30103)/100000;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __FLT_MIN__;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __FLT_MAX__;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return -max();}
+
+    static _LIBCPP_CONSTEXPR const bool is_integer = false;
+    static _LIBCPP_CONSTEXPR const bool is_exact = false;
+    static _LIBCPP_CONSTEXPR const int  radix = __FLT_RADIX__;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return __FLT_EPSILON__;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return 0.5F;}
+
+    static _LIBCPP_CONSTEXPR const int  min_exponent = __FLT_MIN_EXP__;
+    static _LIBCPP_CONSTEXPR const int  min_exponent10 = __FLT_MIN_10_EXP__;
+    static _LIBCPP_CONSTEXPR const int  max_exponent = __FLT_MAX_EXP__;
+    static _LIBCPP_CONSTEXPR const int  max_exponent10 = __FLT_MAX_10_EXP__;
+
+    static _LIBCPP_CONSTEXPR const bool has_infinity = true;
+    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = true;
+    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = true;
+    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = denorm_present;
+    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = false;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return __builtin_huge_valf();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return __builtin_nanf("");}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return __builtin_nansf("");}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return __FLT_DENORM_MIN__;}
+
+    static _LIBCPP_CONSTEXPR const bool is_iec559 = true;
+    static _LIBCPP_CONSTEXPR const bool is_bounded = true;
+    static _LIBCPP_CONSTEXPR const bool is_modulo = false;
+
+    static _LIBCPP_CONSTEXPR const bool traps = false;
+    static _LIBCPP_CONSTEXPR const bool tinyness_before = false;
+    static _LIBCPP_CONSTEXPR const float_round_style round_style = round_to_nearest;
+};
+
+template <>
+class __libcpp_numeric_limits<double, true>
+{
+protected:
+    typedef double type;
+
+    static _LIBCPP_CONSTEXPR const bool is_specialized = true;
+
+    static _LIBCPP_CONSTEXPR const bool is_signed = true;
+    static _LIBCPP_CONSTEXPR const int  digits = __DBL_MANT_DIG__;
+    static _LIBCPP_CONSTEXPR const int  digits10 = __DBL_DIG__;
+    static _LIBCPP_CONSTEXPR const int  max_digits10 = 2+(digits * 30103)/100000;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __DBL_MIN__;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __DBL_MAX__;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return -max();}
+
+    static _LIBCPP_CONSTEXPR const bool is_integer = false;
+    static _LIBCPP_CONSTEXPR const bool is_exact = false;
+    static _LIBCPP_CONSTEXPR const int  radix = __FLT_RADIX__;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return __DBL_EPSILON__;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return 0.5;}
+
+    static _LIBCPP_CONSTEXPR const int  min_exponent = __DBL_MIN_EXP__;
+    static _LIBCPP_CONSTEXPR const int  min_exponent10 = __DBL_MIN_10_EXP__;
+    static _LIBCPP_CONSTEXPR const int  max_exponent = __DBL_MAX_EXP__;
+    static _LIBCPP_CONSTEXPR const int  max_exponent10 = __DBL_MAX_10_EXP__;
+
+    static _LIBCPP_CONSTEXPR const bool has_infinity = true;
+    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = true;
+    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = true;
+    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = denorm_present;
+    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = false;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return __builtin_huge_val();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return __builtin_nan("");}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return __builtin_nans("");}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return __DBL_DENORM_MIN__;}
+
+    static _LIBCPP_CONSTEXPR const bool is_iec559 = true;
+    static _LIBCPP_CONSTEXPR const bool is_bounded = true;
+    static _LIBCPP_CONSTEXPR const bool is_modulo = false;
+
+    static _LIBCPP_CONSTEXPR const bool traps = false;
+    static _LIBCPP_CONSTEXPR const bool tinyness_before = false;
+    static _LIBCPP_CONSTEXPR const float_round_style round_style = round_to_nearest;
+};
+
+template <>
+class __libcpp_numeric_limits<long double, true>
+{
+protected:
+    typedef long double type;
+
+    static _LIBCPP_CONSTEXPR const bool is_specialized = true;
+
+    static _LIBCPP_CONSTEXPR const bool is_signed = true;
+    static _LIBCPP_CONSTEXPR const int  digits = __LDBL_MANT_DIG__;
+    static _LIBCPP_CONSTEXPR const int  digits10 = __LDBL_DIG__;
+    static _LIBCPP_CONSTEXPR const int  max_digits10 = 2+(digits * 30103)/100000;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __LDBL_MIN__;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __LDBL_MAX__;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return -max();}
+
+    static _LIBCPP_CONSTEXPR const bool is_integer = false;
+    static _LIBCPP_CONSTEXPR const bool is_exact = false;
+    static _LIBCPP_CONSTEXPR const int  radix = __FLT_RADIX__;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return __LDBL_EPSILON__;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return 0.5;}
+
+    static _LIBCPP_CONSTEXPR const int  min_exponent = __LDBL_MIN_EXP__;
+    static _LIBCPP_CONSTEXPR const int  min_exponent10 = __LDBL_MIN_10_EXP__;
+    static _LIBCPP_CONSTEXPR const int  max_exponent = __LDBL_MAX_EXP__;
+    static _LIBCPP_CONSTEXPR const int  max_exponent10 = __LDBL_MAX_10_EXP__;
+
+    static _LIBCPP_CONSTEXPR const bool has_infinity = true;
+    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = true;
+    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = true;
+    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = denorm_present;
+    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = false;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return __builtin_huge_vall();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return __builtin_nanl("");}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return __builtin_nansl("");}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return __LDBL_DENORM_MIN__;}
+
+#if (defined(__ppc__) || defined(__ppc64__))
+    static _LIBCPP_CONSTEXPR const bool is_iec559 = false;
+#else
+    static _LIBCPP_CONSTEXPR const bool is_iec559 = true;
+#endif
+    static _LIBCPP_CONSTEXPR const bool is_bounded = true;
+    static _LIBCPP_CONSTEXPR const bool is_modulo = false;
+
+    static _LIBCPP_CONSTEXPR const bool traps = false;
+    static _LIBCPP_CONSTEXPR const bool tinyness_before = false;
+    static _LIBCPP_CONSTEXPR const float_round_style round_style = round_to_nearest;
+};
+
+template <class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY numeric_limits
+    : private __libcpp_numeric_limits<typename remove_cv<_Tp>::type>
+{
+    typedef __libcpp_numeric_limits<typename remove_cv<_Tp>::type> __base;
+    typedef typename __base::type type;
+public:
+    static _LIBCPP_CONSTEXPR const bool is_specialized = __base::is_specialized;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __base::min();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __base::max();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return __base::lowest();}
+
+    static _LIBCPP_CONSTEXPR const int  digits = __base::digits;
+    static _LIBCPP_CONSTEXPR const int  digits10 = __base::digits10;
+    static _LIBCPP_CONSTEXPR const int  max_digits10 = __base::max_digits10;
+    static _LIBCPP_CONSTEXPR const bool is_signed = __base::is_signed;
+    static _LIBCPP_CONSTEXPR const bool is_integer = __base::is_integer;
+    static _LIBCPP_CONSTEXPR const bool is_exact = __base::is_exact;
+    static _LIBCPP_CONSTEXPR const int  radix = __base::radix;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return __base::epsilon();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return __base::round_error();}
+
+    static _LIBCPP_CONSTEXPR const int  min_exponent = __base::min_exponent;
+    static _LIBCPP_CONSTEXPR const int  min_exponent10 = __base::min_exponent10;
+    static _LIBCPP_CONSTEXPR const int  max_exponent = __base::max_exponent;
+    static _LIBCPP_CONSTEXPR const int  max_exponent10 = __base::max_exponent10;
+
+    static _LIBCPP_CONSTEXPR const bool has_infinity = __base::has_infinity;
+    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = __base::has_quiet_NaN;
+    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = __base::has_signaling_NaN;
+    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = __base::has_denorm;
+    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = __base::has_denorm_loss;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return __base::infinity();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return __base::quiet_NaN();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return __base::signaling_NaN();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return __base::denorm_min();}
+
+    static _LIBCPP_CONSTEXPR const bool is_iec559 = __base::is_iec559;
+    static _LIBCPP_CONSTEXPR const bool is_bounded = __base::is_bounded;
+    static _LIBCPP_CONSTEXPR const bool is_modulo = __base::is_modulo;
+
+    static _LIBCPP_CONSTEXPR const bool traps = __base::traps;
+    static _LIBCPP_CONSTEXPR const bool tinyness_before = __base::tinyness_before;
+    static _LIBCPP_CONSTEXPR const float_round_style round_style = __base::round_style;
+};
+
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::is_specialized;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<_Tp>::digits;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<_Tp>::digits10;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<_Tp>::max_digits10;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::is_signed;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::is_integer;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::is_exact;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<_Tp>::radix;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<_Tp>::min_exponent;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<_Tp>::min_exponent10;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<_Tp>::max_exponent;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<_Tp>::max_exponent10;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::has_infinity;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::has_quiet_NaN;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::has_signaling_NaN;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const float_denorm_style numeric_limits<_Tp>::has_denorm;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::has_denorm_loss;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::is_iec559;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::is_bounded;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::is_modulo;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::traps;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::tinyness_before;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const float_round_style numeric_limits<_Tp>::round_style;
+
+template <class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY numeric_limits<const _Tp>
+    : private numeric_limits<_Tp>
+{
+    typedef numeric_limits<_Tp> __base;
+    typedef _Tp type;
+public:
+    static _LIBCPP_CONSTEXPR const bool is_specialized = __base::is_specialized;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __base::min();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __base::max();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return __base::lowest();}
+
+    static _LIBCPP_CONSTEXPR const int  digits = __base::digits;
+    static _LIBCPP_CONSTEXPR const int  digits10 = __base::digits10;
+    static _LIBCPP_CONSTEXPR const int  max_digits10 = __base::max_digits10;
+    static _LIBCPP_CONSTEXPR const bool is_signed = __base::is_signed;
+    static _LIBCPP_CONSTEXPR const bool is_integer = __base::is_integer;
+    static _LIBCPP_CONSTEXPR const bool is_exact = __base::is_exact;
+    static _LIBCPP_CONSTEXPR const int  radix = __base::radix;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return __base::epsilon();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return __base::round_error();}
+
+    static _LIBCPP_CONSTEXPR const int  min_exponent = __base::min_exponent;
+    static _LIBCPP_CONSTEXPR const int  min_exponent10 = __base::min_exponent10;
+    static _LIBCPP_CONSTEXPR const int  max_exponent = __base::max_exponent;
+    static _LIBCPP_CONSTEXPR const int  max_exponent10 = __base::max_exponent10;
+
+    static _LIBCPP_CONSTEXPR const bool has_infinity = __base::has_infinity;
+    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = __base::has_quiet_NaN;
+    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = __base::has_signaling_NaN;
+    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = __base::has_denorm;
+    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = __base::has_denorm_loss;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return __base::infinity();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return __base::quiet_NaN();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return __base::signaling_NaN();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return __base::denorm_min();}
+
+    static _LIBCPP_CONSTEXPR const bool is_iec559 = __base::is_iec559;
+    static _LIBCPP_CONSTEXPR const bool is_bounded = __base::is_bounded;
+    static _LIBCPP_CONSTEXPR const bool is_modulo = __base::is_modulo;
+
+    static _LIBCPP_CONSTEXPR const bool traps = __base::traps;
+    static _LIBCPP_CONSTEXPR const bool tinyness_before = __base::tinyness_before;
+    static _LIBCPP_CONSTEXPR const float_round_style round_style = __base::round_style;
+};
+
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::is_specialized;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<const _Tp>::digits;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<const _Tp>::digits10;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<const _Tp>::max_digits10;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::is_signed;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::is_integer;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::is_exact;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<const _Tp>::radix;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<const _Tp>::min_exponent;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<const _Tp>::min_exponent10;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<const _Tp>::max_exponent;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<const _Tp>::max_exponent10;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::has_infinity;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::has_quiet_NaN;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::has_signaling_NaN;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const float_denorm_style numeric_limits<const _Tp>::has_denorm;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::has_denorm_loss;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::is_iec559;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::is_bounded;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::is_modulo;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::traps;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::tinyness_before;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const float_round_style numeric_limits<const _Tp>::round_style;
+
+template <class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY numeric_limits<volatile _Tp>
+    : private numeric_limits<_Tp>
+{
+    typedef numeric_limits<_Tp> __base;
+    typedef _Tp type;
+public:
+    static _LIBCPP_CONSTEXPR const bool is_specialized = __base::is_specialized;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __base::min();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __base::max();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return __base::lowest();}
+
+    static _LIBCPP_CONSTEXPR const int  digits = __base::digits;
+    static _LIBCPP_CONSTEXPR const int  digits10 = __base::digits10;
+    static _LIBCPP_CONSTEXPR const int  max_digits10 = __base::max_digits10;
+    static _LIBCPP_CONSTEXPR const bool is_signed = __base::is_signed;
+    static _LIBCPP_CONSTEXPR const bool is_integer = __base::is_integer;
+    static _LIBCPP_CONSTEXPR const bool is_exact = __base::is_exact;
+    static _LIBCPP_CONSTEXPR const int  radix = __base::radix;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return __base::epsilon();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return __base::round_error();}
+
+    static _LIBCPP_CONSTEXPR const int  min_exponent = __base::min_exponent;
+    static _LIBCPP_CONSTEXPR const int  min_exponent10 = __base::min_exponent10;
+    static _LIBCPP_CONSTEXPR const int  max_exponent = __base::max_exponent;
+    static _LIBCPP_CONSTEXPR const int  max_exponent10 = __base::max_exponent10;
+
+    static _LIBCPP_CONSTEXPR const bool has_infinity = __base::has_infinity;
+    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = __base::has_quiet_NaN;
+    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = __base::has_signaling_NaN;
+    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = __base::has_denorm;
+    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = __base::has_denorm_loss;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return __base::infinity();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return __base::quiet_NaN();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return __base::signaling_NaN();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return __base::denorm_min();}
+
+    static _LIBCPP_CONSTEXPR const bool is_iec559 = __base::is_iec559;
+    static _LIBCPP_CONSTEXPR const bool is_bounded = __base::is_bounded;
+    static _LIBCPP_CONSTEXPR const bool is_modulo = __base::is_modulo;
+
+    static _LIBCPP_CONSTEXPR const bool traps = __base::traps;
+    static _LIBCPP_CONSTEXPR const bool tinyness_before = __base::tinyness_before;
+    static _LIBCPP_CONSTEXPR const float_round_style round_style = __base::round_style;
+};
+
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::is_specialized;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<volatile _Tp>::digits;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<volatile _Tp>::digits10;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<volatile _Tp>::max_digits10;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::is_signed;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::is_integer;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::is_exact;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<volatile _Tp>::radix;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<volatile _Tp>::min_exponent;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<volatile _Tp>::min_exponent10;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<volatile _Tp>::max_exponent;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<volatile _Tp>::max_exponent10;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::has_infinity;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::has_quiet_NaN;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::has_signaling_NaN;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const float_denorm_style numeric_limits<volatile _Tp>::has_denorm;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::has_denorm_loss;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::is_iec559;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::is_bounded;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::is_modulo;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::traps;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::tinyness_before;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const float_round_style numeric_limits<volatile _Tp>::round_style;
+
+template <class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY numeric_limits<const volatile _Tp>
+    : private numeric_limits<_Tp>
+{
+    typedef numeric_limits<_Tp> __base;
+    typedef _Tp type;
+public:
+    static _LIBCPP_CONSTEXPR const bool is_specialized = __base::is_specialized;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __base::min();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __base::max();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return __base::lowest();}
+
+    static _LIBCPP_CONSTEXPR const int  digits = __base::digits;
+    static _LIBCPP_CONSTEXPR const int  digits10 = __base::digits10;
+    static _LIBCPP_CONSTEXPR const int  max_digits10 = __base::max_digits10;
+    static _LIBCPP_CONSTEXPR const bool is_signed = __base::is_signed;
+    static _LIBCPP_CONSTEXPR const bool is_integer = __base::is_integer;
+    static _LIBCPP_CONSTEXPR const bool is_exact = __base::is_exact;
+    static _LIBCPP_CONSTEXPR const int  radix = __base::radix;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return __base::epsilon();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return __base::round_error();}
+
+    static _LIBCPP_CONSTEXPR const int  min_exponent = __base::min_exponent;
+    static _LIBCPP_CONSTEXPR const int  min_exponent10 = __base::min_exponent10;
+    static _LIBCPP_CONSTEXPR const int  max_exponent = __base::max_exponent;
+    static _LIBCPP_CONSTEXPR const int  max_exponent10 = __base::max_exponent10;
+
+    static _LIBCPP_CONSTEXPR const bool has_infinity = __base::has_infinity;
+    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = __base::has_quiet_NaN;
+    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = __base::has_signaling_NaN;
+    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = __base::has_denorm;
+    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = __base::has_denorm_loss;
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return __base::infinity();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return __base::quiet_NaN();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return __base::signaling_NaN();}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return __base::denorm_min();}
+
+    static _LIBCPP_CONSTEXPR const bool is_iec559 = __base::is_iec559;
+    static _LIBCPP_CONSTEXPR const bool is_bounded = __base::is_bounded;
+    static _LIBCPP_CONSTEXPR const bool is_modulo = __base::is_modulo;
+
+    static _LIBCPP_CONSTEXPR const bool traps = __base::traps;
+    static _LIBCPP_CONSTEXPR const bool tinyness_before = __base::tinyness_before;
+    static _LIBCPP_CONSTEXPR const float_round_style round_style = __base::round_style;
+};
+
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::is_specialized;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<const volatile _Tp>::digits;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<const volatile _Tp>::digits10;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<const volatile _Tp>::max_digits10;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::is_signed;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::is_integer;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::is_exact;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<const volatile _Tp>::radix;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<const volatile _Tp>::min_exponent;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<const volatile _Tp>::min_exponent10;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<const volatile _Tp>::max_exponent;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const int numeric_limits<const volatile _Tp>::max_exponent10;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::has_infinity;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::has_quiet_NaN;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::has_signaling_NaN;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const float_denorm_style numeric_limits<const volatile _Tp>::has_denorm;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::has_denorm_loss;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::is_iec559;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::is_bounded;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::is_modulo;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::traps;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::tinyness_before;
+template <class _Tp>
+    _LIBCPP_CONSTEXPR const float_round_style numeric_limits<const volatile _Tp>::round_style;
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_LIMITS

diff --git a/libcxx/include/list b/libcxx/include/list
new file mode 100644
index 0000000..14201a8
--- /dev/null
+++ b/libcxx/include/list

@@ -0,0 +1,2358 @@
+// -*- C++ -*-
+//===---------------------------- list ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_LIST
+#define _LIBCPP_LIST
+
+/*
+    list synopsis
+
+namespace std
+{
+
+template <class T, class Alloc = allocator<T> >
+class list
+{
+public:
+
+    // types:
+    typedef T value_type;
+    typedef Alloc allocator_type;
+    typedef typename allocator_type::reference reference;
+    typedef typename allocator_type::const_reference const_reference;
+    typedef typename allocator_type::pointer pointer;
+    typedef typename allocator_type::const_pointer const_pointer;
+    typedef implementation-defined iterator;
+    typedef implementation-defined const_iterator;
+    typedef implementation-defined size_type;
+    typedef implementation-defined difference_type;
+    typedef reverse_iterator<iterator> reverse_iterator;
+    typedef reverse_iterator<const_iterator> const_reverse_iterator;
+
+    list()
+        noexcept(is_nothrow_default_constructible<allocator_type>::value);
+    explicit list(const allocator_type& a);
+    explicit list(size_type n);
+    explicit list(size_type n, const allocator_type& a); // C++14
+    list(size_type n, const value_type& value);
+    list(size_type n, const value_type& value, const allocator_type& a);
+    template <class Iter>
+        list(Iter first, Iter last);
+    template <class Iter>
+        list(Iter first, Iter last, const allocator_type& a);
+    list(const list& x);
+    list(const list&, const allocator_type& a);
+    list(list&& x)
+        noexcept(is_nothrow_move_constructible<allocator_type>::value);
+    list(list&&, const allocator_type& a);
+    list(initializer_list<value_type>);
+    list(initializer_list<value_type>, const allocator_type& a);
+
+    ~list();
+
+    list& operator=(const list& x);
+    list& operator=(list&& x)
+        noexcept(
+             allocator_type::propagate_on_container_move_assignment::value &&
+             is_nothrow_move_assignable<allocator_type>::value);
+    list& operator=(initializer_list<value_type>);
+    template <class Iter>
+        void assign(Iter first, Iter last);
+    void assign(size_type n, const value_type& t);
+    void assign(initializer_list<value_type>);
+
+    allocator_type get_allocator() const noexcept;
+
+    iterator begin() noexcept;
+    const_iterator begin() const noexcept;
+    iterator end() noexcept;
+    const_iterator end() const noexcept;
+    reverse_iterator rbegin() noexcept;
+    const_reverse_iterator rbegin() const noexcept;
+    reverse_iterator rend() noexcept;
+    const_reverse_iterator rend() const noexcept;
+    const_iterator cbegin() const noexcept;
+    const_iterator cend() const noexcept;
+    const_reverse_iterator crbegin() const noexcept;
+    const_reverse_iterator crend() const noexcept;
+
+    reference front();
+    const_reference front() const;
+    reference back();
+    const_reference back() const;
+
+    bool empty() const noexcept;
+    size_type size() const noexcept;
+    size_type max_size() const noexcept;
+
+    template <class... Args>
+        void emplace_front(Args&&... args);
+    void pop_front();
+    template <class... Args>
+        void emplace_back(Args&&... args);
+    void pop_back();
+    void push_front(const value_type& x);
+    void push_front(value_type&& x);
+    void push_back(const value_type& x);
+    void push_back(value_type&& x);
+    template <class... Args>
+        iterator emplace(const_iterator position, Args&&... args);
+    iterator insert(const_iterator position, const value_type& x);
+    iterator insert(const_iterator position, value_type&& x);
+    iterator insert(const_iterator position, size_type n, const value_type& x);
+    template <class Iter>
+        iterator insert(const_iterator position, Iter first, Iter last);
+    iterator insert(const_iterator position, initializer_list<value_type> il);
+
+    iterator erase(const_iterator position);
+    iterator erase(const_iterator position, const_iterator last);
+
+    void resize(size_type sz);
+    void resize(size_type sz, const value_type& c);
+
+    void swap(list&)
+        noexcept(allocator_traits<allocator_type>::is_always_equal::value);  // C++17
+    void clear() noexcept;
+
+    void splice(const_iterator position, list& x);
+    void splice(const_iterator position, list&& x);
+    void splice(const_iterator position, list& x, const_iterator i);
+    void splice(const_iterator position, list&& x, const_iterator i);
+    void splice(const_iterator position, list& x, const_iterator first,
+                                                  const_iterator last);
+    void splice(const_iterator position, list&& x, const_iterator first,
+                                                  const_iterator last);
+
+    void remove(const value_type& value);
+    template <class Pred> void remove_if(Pred pred);
+    void unique();
+    template <class BinaryPredicate>
+        void unique(BinaryPredicate binary_pred);
+    void merge(list& x);
+    void merge(list&& x);
+    template <class Compare>
+        void merge(list& x, Compare comp);
+    template <class Compare>
+        void merge(list&& x, Compare comp);
+    void sort();
+    template <class Compare>
+        void sort(Compare comp);
+    void reverse() noexcept;
+};
+
+template <class T, class Alloc>
+    bool operator==(const list<T,Alloc>& x, const list<T,Alloc>& y);
+template <class T, class Alloc>
+    bool operator< (const list<T,Alloc>& x, const list<T,Alloc>& y);
+template <class T, class Alloc>
+    bool operator!=(const list<T,Alloc>& x, const list<T,Alloc>& y);
+template <class T, class Alloc>
+    bool operator> (const list<T,Alloc>& x, const list<T,Alloc>& y);
+template <class T, class Alloc>
+    bool operator>=(const list<T,Alloc>& x, const list<T,Alloc>& y);
+template <class T, class Alloc>
+    bool operator<=(const list<T,Alloc>& x, const list<T,Alloc>& y);
+
+template <class T, class Alloc>
+    void swap(list<T,Alloc>& x, list<T,Alloc>& y)
+         noexcept(noexcept(x.swap(y)));
+
+}  // std
+
+*/
+
+#include <__config>
+
+#include <memory>
+#include <limits>
+#include <initializer_list>
+#include <iterator>
+#include <algorithm>
+
+#include <__undef_min_max>
+
+#include <__debug>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp, class _VoidPtr> struct __list_node;
+
+template <class _Tp, class _VoidPtr>
+struct __list_node_base
+{
+    typedef typename pointer_traits<_VoidPtr>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+        rebind<__list_node<_Tp, _VoidPtr> > pointer;
+#else
+        rebind<__list_node<_Tp, _VoidPtr> >::other pointer;
+#endif
+
+    typedef typename pointer_traits<_VoidPtr>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+        rebind<__list_node_base> __base_pointer;
+#else
+        rebind<__list_node_base>::other __base_pointer;
+#endif
+
+    pointer __prev_;
+    pointer __next_;
+
+    _LIBCPP_INLINE_VISIBILITY
+    __list_node_base() : __prev_(__self()), __next_(__self()) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    pointer __self()
+    {
+        return static_cast<pointer>(pointer_traits<__base_pointer>::pointer_to(*this));
+    }
+};
+
+template <class _Tp, class _VoidPtr>
+struct __list_node
+    : public __list_node_base<_Tp, _VoidPtr>
+{
+    _Tp __value_;
+};
+
+template <class _Tp, class _Alloc = allocator<_Tp> > class _LIBCPP_TYPE_VIS_ONLY list;
+template <class _Tp, class _Alloc> class __list_imp;
+template <class _Tp, class _VoidPtr> class _LIBCPP_TYPE_VIS_ONLY __list_const_iterator;
+
+template <class _Tp, class _VoidPtr>
+class _LIBCPP_TYPE_VIS_ONLY __list_iterator
+{
+    typedef typename pointer_traits<_VoidPtr>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+        rebind<__list_node<_Tp, _VoidPtr> > __node_pointer;
+#else
+        rebind<__list_node<_Tp, _VoidPtr> >::other __node_pointer;
+#endif
+
+    __node_pointer __ptr_;
+
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __list_iterator(__node_pointer __p, const void* __c) _NOEXCEPT
+        : __ptr_(__p)
+    {
+        __get_db()->__insert_ic(this, __c);
+    }
+#else
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __list_iterator(__node_pointer __p) _NOEXCEPT : __ptr_(__p) {}
+#endif
+
+
+
+    template<class, class> friend class list;
+    template<class, class> friend class __list_imp;
+    template<class, class> friend class __list_const_iterator;
+public:
+    typedef bidirectional_iterator_tag       iterator_category;
+    typedef _Tp                              value_type;
+    typedef value_type&                      reference;
+    typedef typename pointer_traits<_VoidPtr>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<value_type>
+#else
+            rebind<value_type>::other
+#endif
+                                             pointer;
+    typedef typename pointer_traits<pointer>::difference_type difference_type;
+
+    _LIBCPP_INLINE_VISIBILITY
+    __list_iterator() _NOEXCEPT : __ptr_(nullptr)
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __get_db()->__insert_i(this);
+#endif
+    }
+
+#if _LIBCPP_DEBUG_LEVEL >= 2
+
+    _LIBCPP_INLINE_VISIBILITY
+    __list_iterator(const __list_iterator& __p)
+        : __ptr_(__p.__ptr_)
+    {
+        __get_db()->__iterator_copy(this, &__p);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    ~__list_iterator()
+    {
+        __get_db()->__erase_i(this);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __list_iterator& operator=(const __list_iterator& __p)
+    {
+        if (this != &__p)
+        {
+            __get_db()->__iterator_copy(this, &__p);
+            __ptr_ = __p.__ptr_;
+        }
+        return *this;
+    }
+
+#endif  // _LIBCPP_DEBUG_LEVEL >= 2
+
+    _LIBCPP_INLINE_VISIBILITY
+    reference operator*() const
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                       "Attempted to dereference a non-dereferenceable list::iterator");
+#endif
+        return __ptr_->__value_;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    pointer operator->() const
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                       "Attempted to dereference a non-dereferenceable list::iterator");
+#endif
+        return pointer_traits<pointer>::pointer_to(__ptr_->__value_);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __list_iterator& operator++()
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                       "Attempted to increment non-incrementable list::iterator");
+#endif
+        __ptr_ = __ptr_->__next_;
+        return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    __list_iterator operator++(int) {__list_iterator __t(*this); ++(*this); return __t;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __list_iterator& operator--()
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__decrementable(this),
+                       "Attempted to decrement non-decrementable list::iterator");
+#endif
+        __ptr_ = __ptr_->__prev_;
+        return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    __list_iterator operator--(int) {__list_iterator __t(*this); --(*this); return __t;}
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator==(const __list_iterator& __x, const __list_iterator& __y)
+    {
+        return __x.__ptr_ == __y.__ptr_;
+    }
+    friend _LIBCPP_INLINE_VISIBILITY
+     bool operator!=(const __list_iterator& __x, const __list_iterator& __y)
+        {return !(__x == __y);}
+};
+
+template <class _Tp, class _VoidPtr>
+class _LIBCPP_TYPE_VIS_ONLY __list_const_iterator
+{
+    typedef typename pointer_traits<_VoidPtr>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+        rebind<__list_node<_Tp, _VoidPtr> > __node_pointer;
+#else
+        rebind<__list_node<_Tp, _VoidPtr> >::other __node_pointer;
+#endif
+
+    __node_pointer __ptr_;
+
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __list_const_iterator(__node_pointer __p, const void* __c) _NOEXCEPT
+        : __ptr_(__p)
+    {
+        __get_db()->__insert_ic(this, __c);
+    }
+#else
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __list_const_iterator(__node_pointer __p) _NOEXCEPT : __ptr_(__p) {}
+#endif
+
+    template<class, class> friend class list;
+    template<class, class> friend class __list_imp;
+public:
+    typedef bidirectional_iterator_tag       iterator_category;
+    typedef _Tp                              value_type;
+    typedef const value_type&                reference;
+    typedef typename pointer_traits<_VoidPtr>::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<const value_type>
+#else
+            rebind<const value_type>::other
+#endif
+                                             pointer;
+    typedef typename pointer_traits<pointer>::difference_type difference_type;
+
+    _LIBCPP_INLINE_VISIBILITY
+    __list_const_iterator() _NOEXCEPT : __ptr_(nullptr)
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __get_db()->__insert_i(this);
+#endif
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    __list_const_iterator(const __list_iterator<_Tp, _VoidPtr>& __p) _NOEXCEPT
+        : __ptr_(__p.__ptr_)
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __get_db()->__iterator_copy(this, &__p);
+#endif
+    }
+
+#if _LIBCPP_DEBUG_LEVEL >= 2
+
+    _LIBCPP_INLINE_VISIBILITY
+    __list_const_iterator(const __list_const_iterator& __p)
+        : __ptr_(__p.__ptr_)
+    {
+        __get_db()->__iterator_copy(this, &__p);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    ~__list_const_iterator()
+    {
+        __get_db()->__erase_i(this);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __list_const_iterator& operator=(const __list_const_iterator& __p)
+    {
+        if (this != &__p)
+        {
+            __get_db()->__iterator_copy(this, &__p);
+            __ptr_ = __p.__ptr_;
+        }
+        return *this;
+    }
+
+#endif  // _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_INLINE_VISIBILITY
+    reference operator*() const
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                       "Attempted to dereference a non-dereferenceable list::const_iterator");
+#endif
+        return __ptr_->__value_;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    pointer operator->() const
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                       "Attempted to dereference a non-dereferenceable list::iterator");
+#endif
+        return pointer_traits<pointer>::pointer_to(__ptr_->__value_);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __list_const_iterator& operator++()
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
+                       "Attempted to increment non-incrementable list::const_iterator");
+#endif
+        __ptr_ = __ptr_->__next_;
+        return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    __list_const_iterator operator++(int) {__list_const_iterator __t(*this); ++(*this); return __t;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __list_const_iterator& operator--()
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        _LIBCPP_ASSERT(__get_const_db()->__decrementable(this),
+                       "Attempted to decrement non-decrementable list::const_iterator");
+#endif
+        __ptr_ = __ptr_->__prev_;
+        return *this;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    __list_const_iterator operator--(int) {__list_const_iterator __t(*this); --(*this); return __t;}
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator==(const __list_const_iterator& __x, const __list_const_iterator& __y)
+    {
+        return __x.__ptr_ == __y.__ptr_;
+    }
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(const __list_const_iterator& __x, const __list_const_iterator& __y)
+        {return !(__x == __y);}
+};
+
+template <class _Tp, class _Alloc>
+class __list_imp
+{
+    __list_imp(const __list_imp&);
+    __list_imp& operator=(const __list_imp&);
+protected:
+    typedef _Tp                                                     value_type;
+    typedef _Alloc                                                  allocator_type;
+    typedef allocator_traits<allocator_type>                        __alloc_traits;
+    typedef typename __alloc_traits::size_type                      size_type;
+    typedef typename __alloc_traits::void_pointer                   __void_pointer;
+    typedef __list_iterator<value_type, __void_pointer>             iterator;
+    typedef __list_const_iterator<value_type, __void_pointer>       const_iterator;
+    typedef __list_node_base<value_type, __void_pointer>            __node_base;
+    typedef __list_node<value_type, __void_pointer>                 __node;
+    typedef typename __rebind_alloc_helper<__alloc_traits, __node>::type __node_allocator;
+    typedef allocator_traits<__node_allocator>                       __node_alloc_traits;
+    typedef typename __node_alloc_traits::pointer                    __node_pointer;
+    typedef typename __node_alloc_traits::pointer                    __node_const_pointer;
+    typedef typename __alloc_traits::pointer                         pointer;
+    typedef typename __alloc_traits::const_pointer                   const_pointer;
+    typedef typename __alloc_traits::difference_type                 difference_type;
+
+    typedef typename __rebind_alloc_helper<__alloc_traits, __node_base>::type __node_base_allocator;
+    typedef typename allocator_traits<__node_base_allocator>::pointer __node_base_pointer;
+
+    __node_base __end_;
+    __compressed_pair<size_type, __node_allocator> __size_alloc_;
+
+    _LIBCPP_INLINE_VISIBILITY
+          size_type& __sz() _NOEXCEPT {return __size_alloc_.first();}
+    _LIBCPP_INLINE_VISIBILITY
+    const size_type& __sz() const _NOEXCEPT
+        {return __size_alloc_.first();}
+    _LIBCPP_INLINE_VISIBILITY
+          __node_allocator& __node_alloc() _NOEXCEPT
+          {return __size_alloc_.second();}
+    _LIBCPP_INLINE_VISIBILITY
+    const __node_allocator& __node_alloc() const _NOEXCEPT
+        {return __size_alloc_.second();}
+
+    static void __unlink_nodes(__node_pointer __f, __node_pointer __l) _NOEXCEPT;
+
+    __list_imp()
+        _NOEXCEPT_(is_nothrow_default_constructible<__node_allocator>::value);
+    __list_imp(const allocator_type& __a);
+    ~__list_imp();
+    void clear() _NOEXCEPT;
+    _LIBCPP_INLINE_VISIBILITY
+    bool empty() const _NOEXCEPT {return __sz() == 0;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator begin() _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        return iterator(__end_.__next_, this);
+#else
+        return iterator(__end_.__next_);
+#endif
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator begin() const  _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        return const_iterator(__end_.__next_, this);
+#else
+        return const_iterator(__end_.__next_);
+#endif
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    iterator end() _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        return iterator(static_cast<__node_pointer>(
+                pointer_traits<__node_base_pointer>::pointer_to(__end_)), this);
+#else
+        return iterator(static_cast<__node_pointer>(
+                      pointer_traits<__node_base_pointer>::pointer_to(__end_)));
+#endif
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator end() const _NOEXCEPT
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        return const_iterator(static_cast<__node_const_pointer>(
+        pointer_traits<__node_base_pointer>::pointer_to(const_cast<__node_base&>(__end_))), this);
+#else
+        return const_iterator(static_cast<__node_const_pointer>(
+        pointer_traits<__node_base_pointer>::pointer_to(const_cast<__node_base&>(__end_))));
+#endif
+    }
+
+    void swap(__list_imp& __c)
+#if _LIBCPP_STD_VER >= 14
+        _NOEXCEPT;
+#else
+        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || 
+                    __is_nothrow_swappable<allocator_type>::value);
+#endif
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __copy_assign_alloc(const __list_imp& __c)
+        {__copy_assign_alloc(__c, integral_constant<bool,
+                      __node_alloc_traits::propagate_on_container_copy_assignment::value>());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__list_imp& __c)
+        _NOEXCEPT_(
+            !__node_alloc_traits::propagate_on_container_move_assignment::value ||
+            is_nothrow_move_assignable<__node_allocator>::value)
+        {__move_assign_alloc(__c, integral_constant<bool,
+                      __node_alloc_traits::propagate_on_container_move_assignment::value>());}
+
+private:
+    _LIBCPP_INLINE_VISIBILITY
+    void __copy_assign_alloc(const __list_imp& __c, true_type)
+        {
+            if (__node_alloc() != __c.__node_alloc())
+                clear();
+            __node_alloc() = __c.__node_alloc();
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __copy_assign_alloc(const __list_imp& __c, false_type)
+        {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__list_imp& __c, true_type)
+        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value)
+        {
+            __node_alloc() = _VSTD::move(__c.__node_alloc());
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __move_assign_alloc(__list_imp& __c, false_type)
+        _NOEXCEPT
+        {}
+};
+
+// Unlink nodes [__f, __l]
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+__list_imp<_Tp, _Alloc>::__unlink_nodes(__node_pointer __f, __node_pointer __l)
+    _NOEXCEPT
+{
+    __f->__prev_->__next_ = __l->__next_;
+    __l->__next_->__prev_ = __f->__prev_;
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+__list_imp<_Tp, _Alloc>::__list_imp()
+        _NOEXCEPT_(is_nothrow_default_constructible<__node_allocator>::value)
+    : __size_alloc_(0)
+{
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+__list_imp<_Tp, _Alloc>::__list_imp(const allocator_type& __a)
+    : __size_alloc_(0, __node_allocator(__a))
+{
+}
+
+template <class _Tp, class _Alloc>
+__list_imp<_Tp, _Alloc>::~__list_imp()
+{
+    clear();
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->__erase_c(this);
+#endif
+}
+
+template <class _Tp, class _Alloc>
+void
+__list_imp<_Tp, _Alloc>::clear() _NOEXCEPT
+{
+    if (!empty())
+    {
+        __node_allocator& __na = __node_alloc();
+        __node_pointer __f = __end_.__next_;
+        __node_pointer __l = static_cast<__node_pointer>(
+                       pointer_traits<__node_base_pointer>::pointer_to(__end_));
+        __unlink_nodes(__f, __l->__prev_);
+        __sz() = 0;
+        while (__f != __l)
+        {
+            __node_pointer __n = __f;
+            __f = __f->__next_;
+            __node_alloc_traits::destroy(__na, _VSTD::addressof(__n->__value_));
+            __node_alloc_traits::deallocate(__na, __n, 1);
+        }
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __c_node* __c = __get_db()->__find_c_and_lock(this);
+        for (__i_node** __p = __c->end_; __p != __c->beg_; )
+        {
+            --__p;
+            const_iterator* __i = static_cast<const_iterator*>((*__p)->__i_);
+            if (__i->__ptr_ != __l)
+            {
+                (*__p)->__c_ = nullptr;
+                if (--__c->end_ != __p)
+                    memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
+            }
+        }
+        __get_db()->unlock();
+#endif
+    }
+}
+
+template <class _Tp, class _Alloc>
+void
+__list_imp<_Tp, _Alloc>::swap(__list_imp& __c)
+#if _LIBCPP_STD_VER >= 14
+        _NOEXCEPT
+#else
+        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value || 
+                    __is_nothrow_swappable<allocator_type>::value)
+#endif
+{
+    _LIBCPP_ASSERT(__alloc_traits::propagate_on_container_swap::value ||
+                   this->__node_alloc() == __c.__node_alloc(),
+                   "list::swap: Either propagate_on_container_swap must be true"
+                   " or the allocators must compare equal");
+    using _VSTD::swap;
+    __swap_allocator(__node_alloc(), __c.__node_alloc());
+    swap(__sz(), __c.__sz());
+    swap(__end_, __c.__end_);
+    if (__sz() == 0)
+        __end_.__next_ = __end_.__prev_ = __end_.__self();
+    else
+        __end_.__prev_->__next_ = __end_.__next_->__prev_ = __end_.__self();
+    if (__c.__sz() == 0)
+        __c.__end_.__next_ = __c.__end_.__prev_ = __c.__end_.__self();
+    else
+        __c.__end_.__prev_->__next_ = __c.__end_.__next_->__prev_ = __c.__end_.__self();
+
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __libcpp_db* __db = __get_db();
+    __c_node* __cn1 = __db->__find_c_and_lock(this);
+    __c_node* __cn2 = __db->__find_c(&__c);
+    std::swap(__cn1->beg_, __cn2->beg_);
+    std::swap(__cn1->end_, __cn2->end_);
+    std::swap(__cn1->cap_, __cn2->cap_);
+    for (__i_node** __p = __cn1->end_; __p != __cn1->beg_;)
+    {
+        --__p;
+        const_iterator* __i = static_cast<const_iterator*>((*__p)->__i_);
+        if (__i->__ptr_ == static_cast<__node_pointer>(
+                       pointer_traits<__node_base_pointer>::pointer_to(__c.__end_)))
+        {
+            __cn2->__add(*__p);
+            if (--__cn1->end_ != __p)
+                memmove(__p, __p+1, (__cn1->end_ - __p)*sizeof(__i_node*));
+        }
+        else
+            (*__p)->__c_ = __cn1;
+    }
+    for (__i_node** __p = __cn2->end_; __p != __cn2->beg_;)
+    {
+        --__p;
+        const_iterator* __i = static_cast<const_iterator*>((*__p)->__i_);
+        if (__i->__ptr_ == static_cast<__node_pointer>(
+                       pointer_traits<__node_base_pointer>::pointer_to(__end_)))
+        {
+            __cn1->__add(*__p);
+            if (--__cn2->end_ != __p)
+                memmove(__p, __p+1, (__cn2->end_ - __p)*sizeof(__i_node*));
+        }
+        else
+            (*__p)->__c_ = __cn2;
+    }
+    __db->unlock();
+#endif
+}
+
+template <class _Tp, class _Alloc /*= allocator<_Tp>*/>
+class _LIBCPP_TYPE_VIS_ONLY list
+    : private __list_imp<_Tp, _Alloc>
+{
+    typedef __list_imp<_Tp, _Alloc> base;
+    typedef typename base::__node              __node;
+    typedef typename base::__node_allocator    __node_allocator;
+    typedef typename base::__node_pointer      __node_pointer;
+    typedef typename base::__node_alloc_traits __node_alloc_traits;
+    typedef typename base::__node_base         __node_base;
+    typedef typename base::__node_base_pointer __node_base_pointer;
+
+public:
+    typedef _Tp                                      value_type;
+    typedef _Alloc                                   allocator_type;
+    static_assert((is_same<value_type, typename allocator_type::value_type>::value),
+                  "Invalid allocator::value_type");
+    typedef value_type&                              reference;
+    typedef const value_type&                        const_reference;
+    typedef typename base::pointer                   pointer;
+    typedef typename base::const_pointer             const_pointer;
+    typedef typename base::size_type                 size_type;
+    typedef typename base::difference_type           difference_type;
+    typedef typename base::iterator                  iterator;
+    typedef typename base::const_iterator            const_iterator;
+    typedef _VSTD::reverse_iterator<iterator>         reverse_iterator;
+    typedef _VSTD::reverse_iterator<const_iterator>   const_reverse_iterator;
+
+    _LIBCPP_INLINE_VISIBILITY
+    list()
+        _NOEXCEPT_(is_nothrow_default_constructible<__node_allocator>::value)
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __get_db()->__insert_c(this);
+#endif
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    explicit list(const allocator_type& __a) : base(__a)
+    {
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __get_db()->__insert_c(this);
+#endif
+    }
+    explicit list(size_type __n);
+#if _LIBCPP_STD_VER > 11
+    explicit list(size_type __n, const allocator_type& __a);
+#endif
+    list(size_type __n, const value_type& __x);
+    list(size_type __n, const value_type& __x, const allocator_type& __a);
+    template <class _InpIter>
+        list(_InpIter __f, _InpIter __l,
+             typename enable_if<__is_input_iterator<_InpIter>::value>::type* = 0);
+    template <class _InpIter>
+        list(_InpIter __f, _InpIter __l, const allocator_type& __a,
+             typename enable_if<__is_input_iterator<_InpIter>::value>::type* = 0);
+
+    list(const list& __c);
+    list(const list& __c, const allocator_type& __a);
+    list& operator=(const list& __c);
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+    list(initializer_list<value_type> __il);
+    list(initializer_list<value_type> __il, const allocator_type& __a);
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    list(list&& __c)
+        _NOEXCEPT_(is_nothrow_move_constructible<__node_allocator>::value);
+    list(list&& __c, const allocator_type& __a);
+    list& operator=(list&& __c)
+        _NOEXCEPT_(
+            __node_alloc_traits::propagate_on_container_move_assignment::value &&
+            is_nothrow_move_assignable<__node_allocator>::value);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+    _LIBCPP_INLINE_VISIBILITY
+    list& operator=(initializer_list<value_type> __il)
+        {assign(__il.begin(), __il.end()); return *this;}
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+    template <class _InpIter>
+        void assign(_InpIter __f, _InpIter __l,
+             typename enable_if<__is_input_iterator<_InpIter>::value>::type* = 0);
+    void assign(size_type __n, const value_type& __x);
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+    _LIBCPP_INLINE_VISIBILITY
+    void assign(initializer_list<value_type> __il)
+        {assign(__il.begin(), __il.end());}
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+    allocator_type get_allocator() const _NOEXCEPT;
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type size() const _NOEXCEPT     {return base::__sz();}
+    _LIBCPP_INLINE_VISIBILITY
+    bool empty() const _NOEXCEPT         {return base::empty();}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type max_size() const _NOEXCEPT
+        {return numeric_limits<difference_type>::max();}
+
+    _LIBCPP_INLINE_VISIBILITY
+          iterator begin() _NOEXCEPT        {return base::begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator begin()  const _NOEXCEPT {return base::begin();}
+    _LIBCPP_INLINE_VISIBILITY
+          iterator end() _NOEXCEPT          {return base::end();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator end()    const _NOEXCEPT {return base::end();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator cbegin() const _NOEXCEPT {return base::begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator cend()   const _NOEXCEPT {return base::end();}
+
+    _LIBCPP_INLINE_VISIBILITY
+          reverse_iterator rbegin() _NOEXCEPT
+            {return       reverse_iterator(end());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator rbegin()  const _NOEXCEPT
+        {return const_reverse_iterator(end());}
+    _LIBCPP_INLINE_VISIBILITY
+          reverse_iterator rend() _NOEXCEPT
+            {return       reverse_iterator(begin());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator rend()    const _NOEXCEPT
+        {return const_reverse_iterator(begin());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator crbegin() const _NOEXCEPT
+        {return const_reverse_iterator(end());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator crend()   const _NOEXCEPT
+        {return const_reverse_iterator(begin());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    reference front()
+    {
+        _LIBCPP_ASSERT(!empty(), "list::front called on empty list");
+        return base::__end_.__next_->__value_;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    const_reference front() const
+    {
+        _LIBCPP_ASSERT(!empty(), "list::front called on empty list");
+        return base::__end_.__next_->__value_;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    reference back()
+    {
+        _LIBCPP_ASSERT(!empty(), "list::back called on empty list");
+        return base::__end_.__prev_->__value_;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    const_reference back() const
+    {
+        _LIBCPP_ASSERT(!empty(), "list::back called on empty list");
+        return base::__end_.__prev_->__value_;
+    }
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    void push_front(value_type&& __x);
+    void push_back(value_type&& __x);
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    template <class... _Args>
+       void emplace_front(_Args&&... __args);
+    template <class... _Args>
+        void emplace_back(_Args&&... __args);
+    template <class... _Args>
+        iterator emplace(const_iterator __p, _Args&&... __args);
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+    iterator insert(const_iterator __p, value_type&& __x);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    void push_front(const value_type& __x);
+    void push_back(const value_type& __x);
+
+    iterator insert(const_iterator __p, const value_type& __x);
+    iterator insert(const_iterator __p, size_type __n, const value_type& __x);
+    template <class _InpIter>
+        iterator insert(const_iterator __p, _InpIter __f, _InpIter __l,
+             typename enable_if<__is_input_iterator<_InpIter>::value>::type* = 0);
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+    _LIBCPP_INLINE_VISIBILITY
+    iterator insert(const_iterator __p, initializer_list<value_type> __il)
+        {return insert(__p, __il.begin(), __il.end());}
+#endif   // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(list& __c)
+#if _LIBCPP_STD_VER >= 14
+        _NOEXCEPT
+#else
+        _NOEXCEPT_(!__node_alloc_traits::propagate_on_container_swap::value ||
+                   __is_nothrow_swappable<__node_allocator>::value)
+#endif
+        {base::swap(__c);}
+    _LIBCPP_INLINE_VISIBILITY
+    void clear() _NOEXCEPT {base::clear();}
+
+    void pop_front();
+    void pop_back();
+
+    iterator erase(const_iterator __p);
+    iterator erase(const_iterator __f, const_iterator __l);
+
+    void resize(size_type __n);
+    void resize(size_type __n, const value_type& __x);
+
+    void splice(const_iterator __p, list& __c);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    void splice(const_iterator __p, list&& __c) {splice(__p, __c);}
+#endif
+    void splice(const_iterator __p, list& __c, const_iterator __i);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    void splice(const_iterator __p, list&& __c, const_iterator __i)
+        {splice(__p, __c, __i);}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    void splice(const_iterator __p, list& __c, const_iterator __f, const_iterator __l);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    void splice(const_iterator __p, list&& __c, const_iterator __f, const_iterator __l)
+        {splice(__p, __c, __f, __l);}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    void remove(const value_type& __x);
+    template <class _Pred> void remove_if(_Pred __pred);
+    void unique();
+    template <class _BinaryPred>
+        void unique(_BinaryPred __binary_pred);
+    void merge(list& __c);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    void merge(list&& __c) {merge(__c);}
+#endif
+    template <class _Comp>
+        void merge(list& __c, _Comp __comp);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template <class _Comp>
+    _LIBCPP_INLINE_VISIBILITY
+        void merge(list&& __c, _Comp __comp) {merge(__c, __comp);}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    void sort();
+    template <class _Comp>
+        void sort(_Comp __comp);
+
+    void reverse() _NOEXCEPT;
+
+    bool __invariants() const;
+
+#if _LIBCPP_DEBUG_LEVEL >= 2
+
+    bool __dereferenceable(const const_iterator* __i) const;
+    bool __decrementable(const const_iterator* __i) const;
+    bool __addable(const const_iterator* __i, ptrdiff_t __n) const;
+    bool __subscriptable(const const_iterator* __i, ptrdiff_t __n) const;
+
+#endif  // _LIBCPP_DEBUG_LEVEL >= 2
+
+private:
+    static void __link_nodes  (__node_pointer __p, __node_pointer __f, __node_pointer __l);
+    void __link_nodes_at_front(__node_pointer __f, __node_pointer __l);
+    void __link_nodes_at_back (__node_pointer __f, __node_pointer __l);
+    iterator __iterator(size_type __n);
+    template <class _Comp>
+        static iterator __sort(iterator __f1, iterator __e2, size_type __n, _Comp& __comp);
+
+    void __move_assign(list& __c, true_type)
+        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value);
+    void __move_assign(list& __c, false_type);
+};
+
+// Link in nodes [__f, __l] just prior to __p
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+list<_Tp, _Alloc>::__link_nodes(__node_pointer __p, __node_pointer __f, __node_pointer __l)
+{
+    __p->__prev_->__next_ = __f;
+    __f->__prev_ = __p->__prev_;
+    __p->__prev_ = __l;
+    __l->__next_ = __p;
+}
+
+// Link in nodes [__f, __l] at the front of the list
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+list<_Tp, _Alloc>::__link_nodes_at_front(__node_pointer __f, __node_pointer __l)
+{
+    __f->__prev_ = base::__end_.__self();
+    __l->__next_ = base::__end_.__next_;
+    __l->__next_->__prev_ = __l;
+    base::__end_.__next_ = __f;
+}
+
+// Link in nodes [__f, __l] at the front of the list
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+list<_Tp, _Alloc>::__link_nodes_at_back(__node_pointer __f, __node_pointer __l)
+{
+    __l->__next_ = base::__end_.__self();
+    __f->__prev_ = base::__end_.__prev_;
+    __f->__prev_->__next_ = __f;
+    base::__end_.__prev_ = __l;
+}
+
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+typename list<_Tp, _Alloc>::iterator
+list<_Tp, _Alloc>::__iterator(size_type __n)
+{
+    return __n <= base::__sz() / 2 ? _VSTD::next(begin(), __n)
+                                   : _VSTD::prev(end(), base::__sz() - __n);
+}
+
+template <class _Tp, class _Alloc>
+list<_Tp, _Alloc>::list(size_type __n)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->__insert_c(this);
+#endif
+    for (; __n > 0; --__n)
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+        emplace_back();
+#else
+        push_back(value_type());
+#endif
+}
+
+#if _LIBCPP_STD_VER > 11
+template <class _Tp, class _Alloc>
+list<_Tp, _Alloc>::list(size_type __n, const allocator_type& __a) : base(__a)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->__insert_c(this);
+#endif
+    for (; __n > 0; --__n)
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+        emplace_back();
+#else
+        push_back(value_type());
+#endif
+}
+#endif
+
+template <class _Tp, class _Alloc>
+list<_Tp, _Alloc>::list(size_type __n, const value_type& __x)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->__insert_c(this);
+#endif
+    for (; __n > 0; --__n)
+        push_back(__x);
+}
+
+template <class _Tp, class _Alloc>
+list<_Tp, _Alloc>::list(size_type __n, const value_type& __x, const allocator_type& __a)
+    : base(__a)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->__insert_c(this);
+#endif
+    for (; __n > 0; --__n)
+        push_back(__x);
+}
+
+template <class _Tp, class _Alloc>
+template <class _InpIter>
+list<_Tp, _Alloc>::list(_InpIter __f, _InpIter __l,
+                        typename enable_if<__is_input_iterator<_InpIter>::value>::type*)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->__insert_c(this);
+#endif
+    for (; __f != __l; ++__f)
+        push_back(*__f);
+}
+
+template <class _Tp, class _Alloc>
+template <class _InpIter>
+list<_Tp, _Alloc>::list(_InpIter __f, _InpIter __l, const allocator_type& __a,
+                        typename enable_if<__is_input_iterator<_InpIter>::value>::type*)
+    : base(__a)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->__insert_c(this);
+#endif
+    for (; __f != __l; ++__f)
+        push_back(*__f);
+}
+
+template <class _Tp, class _Alloc>
+list<_Tp, _Alloc>::list(const list& __c)
+    : base(allocator_type(
+           __node_alloc_traits::select_on_container_copy_construction(
+                __c.__node_alloc())))
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->__insert_c(this);
+#endif
+    for (const_iterator __i = __c.begin(), __e = __c.end(); __i != __e; ++__i)
+        push_back(*__i);
+}
+
+template <class _Tp, class _Alloc>
+list<_Tp, _Alloc>::list(const list& __c, const allocator_type& __a)
+    : base(__a)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->__insert_c(this);
+#endif
+    for (const_iterator __i = __c.begin(), __e = __c.end(); __i != __e; ++__i)
+        push_back(*__i);
+}
+
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+template <class _Tp, class _Alloc>
+list<_Tp, _Alloc>::list(initializer_list<value_type> __il, const allocator_type& __a)
+    : base(__a)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->__insert_c(this);
+#endif
+    for (typename initializer_list<value_type>::const_iterator __i = __il.begin(),
+            __e = __il.end(); __i != __e; ++__i)
+        push_back(*__i);
+}
+
+template <class _Tp, class _Alloc>
+list<_Tp, _Alloc>::list(initializer_list<value_type> __il)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->__insert_c(this);
+#endif
+    for (typename initializer_list<value_type>::const_iterator __i = __il.begin(),
+            __e = __il.end(); __i != __e; ++__i)
+        push_back(*__i);
+}
+
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+list<_Tp, _Alloc>&
+list<_Tp, _Alloc>::operator=(const list& __c)
+{
+    if (this != &__c)
+    {
+        base::__copy_assign_alloc(__c);
+        assign(__c.begin(), __c.end());
+    }
+    return *this;
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+list<_Tp, _Alloc>::list(list&& __c)
+    _NOEXCEPT_(is_nothrow_move_constructible<__node_allocator>::value)
+    : base(allocator_type(_VSTD::move(__c.__node_alloc())))
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->__insert_c(this);
+#endif
+    splice(end(), __c);
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+list<_Tp, _Alloc>::list(list&& __c, const allocator_type& __a)
+    : base(__a)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __get_db()->__insert_c(this);
+#endif
+    if (__a == __c.get_allocator())
+        splice(end(), __c);
+    else
+    {
+        typedef move_iterator<iterator> _Ip;
+        assign(_Ip(__c.begin()), _Ip(__c.end()));
+    }
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+list<_Tp, _Alloc>&
+list<_Tp, _Alloc>::operator=(list&& __c)
+        _NOEXCEPT_(
+            __node_alloc_traits::propagate_on_container_move_assignment::value &&
+            is_nothrow_move_assignable<__node_allocator>::value)
+{
+    __move_assign(__c, integral_constant<bool,
+          __node_alloc_traits::propagate_on_container_move_assignment::value>());
+    return *this;
+}
+
+template <class _Tp, class _Alloc>
+void
+list<_Tp, _Alloc>::__move_assign(list& __c, false_type)
+{
+    if (base::__node_alloc() != __c.__node_alloc())
+    {
+        typedef move_iterator<iterator> _Ip;
+        assign(_Ip(__c.begin()), _Ip(__c.end()));
+    }
+    else
+        __move_assign(__c, true_type());
+}
+
+template <class _Tp, class _Alloc>
+void
+list<_Tp, _Alloc>::__move_assign(list& __c, true_type)
+        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value)
+{
+    clear();
+    base::__move_assign_alloc(__c);
+    splice(end(), __c);
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Alloc>
+template <class _InpIter>
+void
+list<_Tp, _Alloc>::assign(_InpIter __f, _InpIter __l,
+                          typename enable_if<__is_input_iterator<_InpIter>::value>::type*)
+{
+    iterator __i = begin();
+    iterator __e = end();
+    for (; __f != __l && __i != __e; ++__f, ++__i)
+        *__i = *__f;
+    if (__i == __e)
+        insert(__e, __f, __l);
+    else
+        erase(__i, __e);
+}
+
+template <class _Tp, class _Alloc>
+void
+list<_Tp, _Alloc>::assign(size_type __n, const value_type& __x)
+{
+    iterator __i = begin();
+    iterator __e = end();
+    for (; __n > 0 && __i != __e; --__n, ++__i)
+        *__i = __x;
+    if (__i == __e)
+        insert(__e, __n, __x);
+    else
+        erase(__i, __e);
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+_Alloc
+list<_Tp, _Alloc>::get_allocator() const _NOEXCEPT
+{
+    return allocator_type(base::__node_alloc());
+}
+
+template <class _Tp, class _Alloc>
+typename list<_Tp, _Alloc>::iterator
+list<_Tp, _Alloc>::insert(const_iterator __p, const value_type& __x)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
+        "list::insert(iterator, x) called with an iterator not"
+        " referring to this list");
+#endif
+    __node_allocator& __na = base::__node_alloc();
+    typedef __allocator_destructor<__node_allocator> _Dp;
+    unique_ptr<__node, _Dp> __hold(__node_alloc_traits::allocate(__na, 1), _Dp(__na, 1));
+    __hold->__prev_ = 0;
+    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
+    __link_nodes(__p.__ptr_, __hold.get(), __hold.get());
+    ++base::__sz();
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    return iterator(__hold.release(), this);
+#else
+    return iterator(__hold.release());
+#endif
+}
+
+template <class _Tp, class _Alloc>
+typename list<_Tp, _Alloc>::iterator
+list<_Tp, _Alloc>::insert(const_iterator __p, size_type __n, const value_type& __x)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
+        "list::insert(iterator, n, x) called with an iterator not"
+        " referring to this list");
+    iterator __r(__p.__ptr_, this);
+#else
+    iterator __r(__p.__ptr_);
+#endif
+    if (__n > 0)
+    {
+        size_type __ds = 0;
+        __node_allocator& __na = base::__node_alloc();
+        typedef __allocator_destructor<__node_allocator> _Dp;
+        unique_ptr<__node, _Dp> __hold(__node_alloc_traits::allocate(__na, 1), _Dp(__na, 1));
+        __hold->__prev_ = 0;
+        __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
+        ++__ds;
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __r = iterator(__hold.get(), this);
+#else
+        __r = iterator(__hold.get());
+#endif
+        __hold.release();
+        iterator __e = __r;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        try
+        {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            for (--__n; __n != 0; --__n, ++__e, ++__ds)
+            {
+                __hold.reset(__node_alloc_traits::allocate(__na, 1));
+                __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
+                __e.__ptr_->__next_ = __hold.get();
+                __hold->__prev_ = __e.__ptr_;
+                __hold.release();
+            }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        }
+        catch (...)
+        {
+            while (true)
+            {
+                __node_alloc_traits::destroy(__na, _VSTD::addressof(*__e));
+                __node_pointer __prev = __e.__ptr_->__prev_;
+                __node_alloc_traits::deallocate(__na, __e.__ptr_, 1);
+                if (__prev == 0)
+                    break;
+#if _LIBCPP_DEBUG_LEVEL >= 2
+                __e = iterator(__prev, this);
+#else
+                __e = iterator(__prev);
+#endif
+            }
+            throw;
+        }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        __link_nodes(__p.__ptr_, __r.__ptr_, __e.__ptr_);
+        base::__sz() += __ds;
+    }
+    return __r;
+}
+
+template <class _Tp, class _Alloc>
+template <class _InpIter>
+typename list<_Tp, _Alloc>::iterator
+list<_Tp, _Alloc>::insert(const_iterator __p, _InpIter __f, _InpIter __l,
+             typename enable_if<__is_input_iterator<_InpIter>::value>::type*)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
+        "list::insert(iterator, range) called with an iterator not"
+        " referring to this list");
+    iterator __r(__p.__ptr_, this);
+#else
+    iterator __r(__p.__ptr_);
+#endif
+    if (__f != __l)
+    {
+        size_type __ds = 0;
+        __node_allocator& __na = base::__node_alloc();
+        typedef __allocator_destructor<__node_allocator> _Dp;
+        unique_ptr<__node, _Dp> __hold(__node_alloc_traits::allocate(__na, 1), _Dp(__na, 1));
+        __hold->__prev_ = 0;
+        __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), *__f);
+        ++__ds;
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __r = iterator(__hold.get(), this);
+#else
+        __r = iterator(__hold.get());
+#endif
+        __hold.release();
+        iterator __e = __r;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        try
+        {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            for (++__f; __f != __l; ++__f, (void) ++__e, (void) ++__ds)
+            {
+                __hold.reset(__node_alloc_traits::allocate(__na, 1));
+                __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), *__f);
+                __e.__ptr_->__next_ = __hold.get();
+                __hold->__prev_ = __e.__ptr_;
+                __hold.release();
+            }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        }
+        catch (...)
+        {
+            while (true)
+            {
+                __node_alloc_traits::destroy(__na, _VSTD::addressof(*__e));
+                __node_pointer __prev = __e.__ptr_->__prev_;
+                __node_alloc_traits::deallocate(__na, __e.__ptr_, 1);
+                if (__prev == 0)
+                    break;
+#if _LIBCPP_DEBUG_LEVEL >= 2
+                __e = iterator(__prev, this);
+#else
+                __e = iterator(__prev);
+#endif
+            }
+            throw;
+        }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        __link_nodes(__p.__ptr_, __r.__ptr_, __e.__ptr_);
+        base::__sz() += __ds;
+    }
+    return __r;
+}
+
+template <class _Tp, class _Alloc>
+void
+list<_Tp, _Alloc>::push_front(const value_type& __x)
+{
+    __node_allocator& __na = base::__node_alloc();
+    typedef __allocator_destructor<__node_allocator> _Dp;
+    unique_ptr<__node, _Dp> __hold(__node_alloc_traits::allocate(__na, 1), _Dp(__na, 1));
+    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
+    __link_nodes_at_front(__hold.get(), __hold.get());
+    ++base::__sz();
+    __hold.release();
+}
+
+template <class _Tp, class _Alloc>
+void
+list<_Tp, _Alloc>::push_back(const value_type& __x)
+{
+    __node_allocator& __na = base::__node_alloc();
+    typedef __allocator_destructor<__node_allocator> _Dp;
+    unique_ptr<__node, _Dp> __hold(__node_alloc_traits::allocate(__na, 1), _Dp(__na, 1));
+    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
+    __link_nodes_at_back(__hold.get(), __hold.get());
+    ++base::__sz();
+    __hold.release();
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Alloc>
+void
+list<_Tp, _Alloc>::push_front(value_type&& __x)
+{
+    __node_allocator& __na = base::__node_alloc();
+    typedef __allocator_destructor<__node_allocator> _Dp;
+    unique_ptr<__node, _Dp> __hold(__node_alloc_traits::allocate(__na, 1), _Dp(__na, 1));
+    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), _VSTD::move(__x));
+    __link_nodes_at_front(__hold.get(), __hold.get());
+    ++base::__sz();
+    __hold.release();
+}
+
+template <class _Tp, class _Alloc>
+void
+list<_Tp, _Alloc>::push_back(value_type&& __x)
+{
+    __node_allocator& __na = base::__node_alloc();
+    typedef __allocator_destructor<__node_allocator> _Dp;
+    unique_ptr<__node, _Dp> __hold(__node_alloc_traits::allocate(__na, 1), _Dp(__na, 1));
+    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), _VSTD::move(__x));
+    __link_nodes_at_back(__hold.get(), __hold.get());
+    ++base::__sz();
+    __hold.release();
+}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Alloc>
+template <class... _Args>
+void
+list<_Tp, _Alloc>::emplace_front(_Args&&... __args)
+{
+    __node_allocator& __na = base::__node_alloc();
+    typedef __allocator_destructor<__node_allocator> _Dp;
+    unique_ptr<__node, _Dp> __hold(__node_alloc_traits::allocate(__na, 1), _Dp(__na, 1));
+    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), _VSTD::forward<_Args>(__args)...);
+    __link_nodes_at_front(__hold.get(), __hold.get());
+    ++base::__sz();
+    __hold.release();
+}
+
+template <class _Tp, class _Alloc>
+template <class... _Args>
+void
+list<_Tp, _Alloc>::emplace_back(_Args&&... __args)
+{
+    __node_allocator& __na = base::__node_alloc();
+    typedef __allocator_destructor<__node_allocator> _Dp;
+    unique_ptr<__node, _Dp> __hold(__node_alloc_traits::allocate(__na, 1), _Dp(__na, 1));
+    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), _VSTD::forward<_Args>(__args)...);
+    __link_nodes_at_back(__hold.get(), __hold.get());
+    ++base::__sz();
+    __hold.release();
+}
+
+template <class _Tp, class _Alloc>
+template <class... _Args>
+typename list<_Tp, _Alloc>::iterator
+list<_Tp, _Alloc>::emplace(const_iterator __p, _Args&&... __args)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
+        "list::emplace(iterator, args...) called with an iterator not"
+        " referring to this list");
+#endif
+    __node_allocator& __na = base::__node_alloc();
+    typedef __allocator_destructor<__node_allocator> _Dp;
+    unique_ptr<__node, _Dp> __hold(__node_alloc_traits::allocate(__na, 1), _Dp(__na, 1));
+    __hold->__prev_ = 0;
+    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), _VSTD::forward<_Args>(__args)...);
+    __link_nodes(__p.__ptr_, __hold.get(), __hold.get());
+    ++base::__sz();
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    return iterator(__hold.release(), this);
+#else
+    return iterator(__hold.release());
+#endif
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Alloc>
+typename list<_Tp, _Alloc>::iterator
+list<_Tp, _Alloc>::insert(const_iterator __p, value_type&& __x)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
+        "list::insert(iterator, x) called with an iterator not"
+        " referring to this list");
+#endif
+    __node_allocator& __na = base::__node_alloc();
+    typedef __allocator_destructor<__node_allocator> _Dp;
+    unique_ptr<__node, _Dp> __hold(__node_alloc_traits::allocate(__na, 1), _Dp(__na, 1));
+    __hold->__prev_ = 0;
+    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), _VSTD::move(__x));
+    __link_nodes(__p.__ptr_, __hold.get(), __hold.get());
+    ++base::__sz();
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    return iterator(__hold.release(), this);
+#else
+    return iterator(__hold.release());
+#endif
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Alloc>
+void
+list<_Tp, _Alloc>::pop_front()
+{
+    _LIBCPP_ASSERT(!empty(), "list::pop_front() called with empty list");
+    __node_allocator& __na = base::__node_alloc();
+    __node_pointer __n = base::__end_.__next_;
+    base::__unlink_nodes(__n, __n);
+    --base::__sz();
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __c_node* __c = __get_db()->__find_c_and_lock(this);
+    for (__i_node** __p = __c->end_; __p != __c->beg_; )
+    {
+        --__p;
+        iterator* __i = static_cast<iterator*>((*__p)->__i_);
+        if (__i->__ptr_ == __n)
+        {
+            (*__p)->__c_ = nullptr;
+            if (--__c->end_ != __p)
+                memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
+        }
+    }
+    __get_db()->unlock();
+#endif
+    __node_alloc_traits::destroy(__na, _VSTD::addressof(__n->__value_));
+    __node_alloc_traits::deallocate(__na, __n, 1);
+}
+
+template <class _Tp, class _Alloc>
+void
+list<_Tp, _Alloc>::pop_back()
+{
+    _LIBCPP_ASSERT(!empty(), "list::pop_back() called with empty list");
+    __node_allocator& __na = base::__node_alloc();
+    __node_pointer __n = base::__end_.__prev_;
+    base::__unlink_nodes(__n, __n);
+    --base::__sz();
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __c_node* __c = __get_db()->__find_c_and_lock(this);
+    for (__i_node** __p = __c->end_; __p != __c->beg_; )
+    {
+        --__p;
+        iterator* __i = static_cast<iterator*>((*__p)->__i_);
+        if (__i->__ptr_ == __n)
+        {
+            (*__p)->__c_ = nullptr;
+            if (--__c->end_ != __p)
+                memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
+        }
+    }
+    __get_db()->unlock();
+#endif
+    __node_alloc_traits::destroy(__na, _VSTD::addressof(__n->__value_));
+    __node_alloc_traits::deallocate(__na, __n, 1);
+}
+
+template <class _Tp, class _Alloc>
+typename list<_Tp, _Alloc>::iterator
+list<_Tp, _Alloc>::erase(const_iterator __p)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
+        "list::erase(iterator) called with an iterator not"
+        " referring to this list");
+#endif
+    _LIBCPP_ASSERT(__p != end(),
+        "list::erase(iterator) called with a non-dereferenceable iterator");
+    __node_allocator& __na = base::__node_alloc();
+    __node_pointer __n = __p.__ptr_;
+    __node_pointer __r = __n->__next_;
+    base::__unlink_nodes(__n, __n);
+    --base::__sz();
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    __c_node* __c = __get_db()->__find_c_and_lock(this);
+    for (__i_node** __p = __c->end_; __p != __c->beg_; )
+    {
+        --__p;
+        iterator* __i = static_cast<iterator*>((*__p)->__i_);
+        if (__i->__ptr_ == __n)
+        {
+            (*__p)->__c_ = nullptr;
+            if (--__c->end_ != __p)
+                memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
+        }
+    }
+    __get_db()->unlock();
+#endif
+    __node_alloc_traits::destroy(__na, _VSTD::addressof(__n->__value_));
+    __node_alloc_traits::deallocate(__na, __n, 1);
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    return iterator(__r, this);
+#else
+    return iterator(__r);
+#endif
+}
+
+template <class _Tp, class _Alloc>
+typename list<_Tp, _Alloc>::iterator
+list<_Tp, _Alloc>::erase(const_iterator __f, const_iterator __l)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__f) == this,
+        "list::erase(iterator, iterator) called with an iterator not"
+        " referring to this list");
+#endif
+    if (__f != __l)
+    {
+        __node_allocator& __na = base::__node_alloc();
+        base::__unlink_nodes(__f.__ptr_, __l.__ptr_->__prev_);
+        while (__f != __l)
+        {
+            __node_pointer __n = __f.__ptr_;
+            ++__f;
+            --base::__sz();
+#if _LIBCPP_DEBUG_LEVEL >= 2
+            __c_node* __c = __get_db()->__find_c_and_lock(this);
+            for (__i_node** __p = __c->end_; __p != __c->beg_; )
+            {
+                --__p;
+                iterator* __i = static_cast<iterator*>((*__p)->__i_);
+                if (__i->__ptr_ == __n)
+                {
+                    (*__p)->__c_ = nullptr;
+                    if (--__c->end_ != __p)
+                        memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
+                }
+            }
+            __get_db()->unlock();
+#endif
+            __node_alloc_traits::destroy(__na, _VSTD::addressof(__n->__value_));
+            __node_alloc_traits::deallocate(__na, __n, 1);
+        }
+    }
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    return iterator(__l.__ptr_, this);
+#else
+    return iterator(__l.__ptr_);
+#endif
+}
+
+template <class _Tp, class _Alloc>
+void
+list<_Tp, _Alloc>::resize(size_type __n)
+{
+    if (__n < base::__sz())
+        erase(__iterator(__n), end());
+    else if (__n > base::__sz())
+    {
+        __n -= base::__sz();
+        size_type __ds = 0;
+        __node_allocator& __na = base::__node_alloc();
+        typedef __allocator_destructor<__node_allocator> _Dp;
+        unique_ptr<__node, _Dp> __hold(__node_alloc_traits::allocate(__na, 1), _Dp(__na, 1));
+        __hold->__prev_ = 0;
+        __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_));
+        ++__ds;
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        iterator __r = iterator(__hold.release(), this);
+#else
+        iterator __r = iterator(__hold.release());
+#endif
+        iterator __e = __r;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        try
+        {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            for (--__n; __n != 0; --__n, ++__e, ++__ds)
+            {
+                __hold.reset(__node_alloc_traits::allocate(__na, 1));
+                __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_));
+                __e.__ptr_->__next_ = __hold.get();
+                __hold->__prev_ = __e.__ptr_;
+                __hold.release();
+            }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        }
+        catch (...)
+        {
+            while (true)
+            {
+                __node_alloc_traits::destroy(__na, _VSTD::addressof(*__e));
+                __node_pointer __prev = __e.__ptr_->__prev_;
+                __node_alloc_traits::deallocate(__na, __e.__ptr_, 1);
+                if (__prev == 0)
+                    break;
+#if _LIBCPP_DEBUG_LEVEL >= 2
+                __e = iterator(__prev, this);
+#else
+                __e = iterator(__prev);
+#endif
+            }
+            throw;
+        }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        __link_nodes_at_back(__r.__ptr_, __e.__ptr_);
+        base::__sz() += __ds;
+    }
+}
+
+template <class _Tp, class _Alloc>
+void
+list<_Tp, _Alloc>::resize(size_type __n, const value_type& __x)
+{
+    if (__n < base::__sz())
+        erase(__iterator(__n), end());
+    else if (__n > base::__sz())
+    {
+        __n -= base::__sz();
+        size_type __ds = 0;
+        __node_allocator& __na = base::__node_alloc();
+        typedef __allocator_destructor<__node_allocator> _Dp;
+        unique_ptr<__node, _Dp> __hold(__node_alloc_traits::allocate(__na, 1), _Dp(__na, 1));
+        __hold->__prev_ = 0;
+        __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
+        ++__ds;
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        iterator __r = iterator(__hold.release(), this);
+#else
+        iterator __r = iterator(__hold.release());
+#endif
+        iterator __e = __r;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        try
+        {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            for (--__n; __n != 0; --__n, ++__e, ++__ds)
+            {
+                __hold.reset(__node_alloc_traits::allocate(__na, 1));
+                __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
+                __e.__ptr_->__next_ = __hold.get();
+                __hold->__prev_ = __e.__ptr_;
+                __hold.release();
+            }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        }
+        catch (...)
+        {
+            while (true)
+            {
+                __node_alloc_traits::destroy(__na, _VSTD::addressof(*__e));
+                __node_pointer __prev = __e.__ptr_->__prev_;
+                __node_alloc_traits::deallocate(__na, __e.__ptr_, 1);
+                if (__prev == 0)
+                    break;
+#if _LIBCPP_DEBUG_LEVEL >= 2
+                __e = iterator(__prev, this);
+#else
+                __e = iterator(__prev);
+#endif
+            }
+            throw;
+        }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        __link_nodes(static_cast<__node_pointer>(pointer_traits<__node_base_pointer>::
+                         pointer_to(base::__end_)), __r.__ptr_, __e.__ptr_);
+        base::__sz() += __ds;
+    }
+}
+
+template <class _Tp, class _Alloc>
+void
+list<_Tp, _Alloc>::splice(const_iterator __p, list& __c)
+{
+    _LIBCPP_ASSERT(this != &__c,
+                   "list::splice(iterator, list) called with this == &list");
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
+        "list::splice(iterator, list) called with an iterator not"
+        " referring to this list");
+#endif
+    if (!__c.empty())
+    {
+        __node_pointer __f = __c.__end_.__next_;
+        __node_pointer __l = __c.__end_.__prev_;
+        base::__unlink_nodes(__f, __l);
+        __link_nodes(__p.__ptr_, __f, __l);
+        base::__sz() += __c.__sz();
+        __c.__sz() = 0;
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __libcpp_db* __db = __get_db();
+        __c_node* __cn1 = __db->__find_c_and_lock(this);
+        __c_node* __cn2 = __db->__find_c(&__c);
+        for (__i_node** __p = __cn2->end_; __p != __cn2->beg_;)
+        {
+            --__p;
+            iterator* __i = static_cast<iterator*>((*__p)->__i_);
+            if (__i->__ptr_ != static_cast<__node_pointer>(
+                       pointer_traits<__node_base_pointer>::pointer_to(__c.__end_)))
+            {
+                __cn1->__add(*__p);
+                (*__p)->__c_ = __cn1;
+                if (--__cn2->end_ != __p)
+                    memmove(__p, __p+1, (__cn2->end_ - __p)*sizeof(__i_node*));
+            }
+        }
+        __db->unlock();
+#endif
+    }
+}
+
+template <class _Tp, class _Alloc>
+void
+list<_Tp, _Alloc>::splice(const_iterator __p, list& __c, const_iterator __i)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
+        "list::splice(iterator, list, iterator) called with first iterator not"
+        " referring to this list");
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__i) == &__c,
+        "list::splice(iterator, list, iterator) called with second iterator not"
+        " referring to list argument");
+    _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(&__i),
+        "list::splice(iterator, list, iterator) called with second iterator not"
+        " derefereceable");
+#endif
+    if (__p.__ptr_ != __i.__ptr_ && __p.__ptr_ != __i.__ptr_->__next_)
+    {
+        __node_pointer __f = __i.__ptr_;
+        base::__unlink_nodes(__f, __f);
+        __link_nodes(__p.__ptr_, __f, __f);
+        --__c.__sz();
+        ++base::__sz();
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __libcpp_db* __db = __get_db();
+        __c_node* __cn1 = __db->__find_c_and_lock(this);
+        __c_node* __cn2 = __db->__find_c(&__c);
+        for (__i_node** __p = __cn2->end_; __p != __cn2->beg_;)
+        {
+            --__p;
+            iterator* __j = static_cast<iterator*>((*__p)->__i_);
+            if (__j->__ptr_ == __f)
+            {
+                __cn1->__add(*__p);
+                (*__p)->__c_ = __cn1;
+                if (--__cn2->end_ != __p)
+                    memmove(__p, __p+1, (__cn2->end_ - __p)*sizeof(__i_node*));
+            }
+        }
+        __db->unlock();
+#endif
+    }
+}
+
+template <class _Tp, class _Alloc>
+void
+list<_Tp, _Alloc>::splice(const_iterator __p, list& __c, const_iterator __f, const_iterator __l)
+{
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
+        "list::splice(iterator, list, iterator, iterator) called with first iterator not"
+        " referring to this list");
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__f) == &__c,
+        "list::splice(iterator, list, iterator, iterator) called with second iterator not"
+        " referring to list argument");
+    if (this == &__c)
+    {
+        for (const_iterator __i = __f; __i != __l; ++__i)
+            _LIBCPP_ASSERT(__i != __p,
+                           "list::splice(iterator, list, iterator, iterator)"
+                           " called with the first iterator within the range"
+                           " of the second and third iterators");
+    }
+#endif
+    if (__f != __l)
+    {
+        if (this != &__c)
+        {
+            size_type __s = _VSTD::distance(__f, __l);
+            __c.__sz() -= __s;
+            base::__sz() += __s;
+        }
+        __node_pointer __first = __f.__ptr_;
+        --__l;
+        __node_pointer __last = __l.__ptr_;
+        base::__unlink_nodes(__first, __last);
+        __link_nodes(__p.__ptr_, __first, __last);
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __libcpp_db* __db = __get_db();
+        __c_node* __cn1 = __db->__find_c_and_lock(this);
+        __c_node* __cn2 = __db->__find_c(&__c);
+        for (__i_node** __p = __cn2->end_; __p != __cn2->beg_;)
+        {
+            --__p;
+            iterator* __j = static_cast<iterator*>((*__p)->__i_);
+            for (__node_pointer __k = __f.__ptr_;
+                                          __k != __l.__ptr_; __k = __k->__next_)
+            {
+                if (__j->__ptr_ == __k)
+                {
+                    __cn1->__add(*__p);
+                    (*__p)->__c_ = __cn1;
+                    if (--__cn2->end_ != __p)
+                        memmove(__p, __p+1, (__cn2->end_ - __p)*sizeof(__i_node*));
+                }
+            }
+        }
+        __db->unlock();
+#endif
+    }
+}
+
+template <class _Tp, class _Alloc>
+void
+list<_Tp, _Alloc>::remove(const value_type& __x)
+{
+    list<_Tp, _Alloc> __deleted_nodes; // collect the nodes we're removing
+    for (const_iterator __i = begin(), __e = end(); __i != __e;)
+    {
+        if (*__i == __x)
+        {
+            const_iterator __j = _VSTD::next(__i);
+            for (; __j != __e && *__j == __x; ++__j)
+                ;
+            __deleted_nodes.splice(__deleted_nodes.end(), *this, __i, __j);
+            __i = __j;
+            if (__i != __e)
+                ++__i;
+        }
+        else
+            ++__i;
+    }
+}
+
+template <class _Tp, class _Alloc>
+template <class _Pred>
+void
+list<_Tp, _Alloc>::remove_if(_Pred __pred)
+{
+    for (iterator __i = begin(), __e = end(); __i != __e;)
+    {
+        if (__pred(*__i))
+        {
+            iterator __j = _VSTD::next(__i);
+            for (; __j != __e && __pred(*__j); ++__j)
+                ;
+            __i = erase(__i, __j);
+            if (__i != __e)
+                ++__i;
+        }
+        else
+            ++__i;
+    }
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+list<_Tp, _Alloc>::unique()
+{
+    unique(__equal_to<value_type>());
+}
+
+template <class _Tp, class _Alloc>
+template <class _BinaryPred>
+void
+list<_Tp, _Alloc>::unique(_BinaryPred __binary_pred)
+{
+    for (iterator __i = begin(), __e = end(); __i != __e;)
+    {
+        iterator __j = _VSTD::next(__i);
+        for (; __j != __e && __binary_pred(*__i, *__j); ++__j)
+            ;
+        if (++__i != __j)
+            __i = erase(__i, __j);
+    }
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+list<_Tp, _Alloc>::merge(list& __c)
+{
+    merge(__c, __less<value_type>());
+}
+
+template <class _Tp, class _Alloc>
+template <class _Comp>
+void
+list<_Tp, _Alloc>::merge(list& __c, _Comp __comp)
+{
+    if (this != &__c)
+    {
+        iterator __f1 = begin();
+        iterator __e1 = end();
+        iterator __f2 = __c.begin();
+        iterator __e2 = __c.end();
+        while (__f1 != __e1 && __f2 != __e2)
+        {
+            if (__comp(*__f2, *__f1))
+            {
+                size_type __ds = 1;
+                iterator __m2 = _VSTD::next(__f2);
+                for (; __m2 != __e2 && __comp(*__m2, *__f1); ++__m2, ++__ds)
+                    ;
+                base::__sz() += __ds;
+                __c.__sz() -= __ds;
+                __node_pointer __f = __f2.__ptr_;
+                __node_pointer __l = __m2.__ptr_->__prev_;
+                __f2 = __m2;
+                base::__unlink_nodes(__f, __l);
+                __m2 = _VSTD::next(__f1);
+                __link_nodes(__f1.__ptr_, __f, __l);
+                __f1 = __m2;
+            }
+            else
+                ++__f1;
+        }
+        splice(__e1, __c);
+#if _LIBCPP_DEBUG_LEVEL >= 2
+        __libcpp_db* __db = __get_db();
+        __c_node* __cn1 = __db->__find_c_and_lock(this);
+        __c_node* __cn2 = __db->__find_c(&__c);
+        for (__i_node** __p = __cn2->end_; __p != __cn2->beg_;)
+        {
+            --__p;
+            iterator* __i = static_cast<iterator*>((*__p)->__i_);
+            if (__i->__ptr_ != static_cast<__node_pointer>(
+                       pointer_traits<__node_base_pointer>::pointer_to(__c.__end_)))
+            {
+                __cn1->__add(*__p);
+                (*__p)->__c_ = __cn1;
+                if (--__cn2->end_ != __p)
+                    memmove(__p, __p+1, (__cn2->end_ - __p)*sizeof(__i_node*));
+            }
+        }
+        __db->unlock();
+#endif
+    }
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+list<_Tp, _Alloc>::sort()
+{
+    sort(__less<value_type>());
+}
+
+template <class _Tp, class _Alloc>
+template <class _Comp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+list<_Tp, _Alloc>::sort(_Comp __comp)
+{
+    __sort(begin(), end(), base::__sz(), __comp);
+}
+
+template <class _Tp, class _Alloc>
+template <class _Comp>
+typename list<_Tp, _Alloc>::iterator
+list<_Tp, _Alloc>::__sort(iterator __f1, iterator __e2, size_type __n, _Comp& __comp)
+{
+    switch (__n)
+    {
+    case 0:
+    case 1:
+        return __f1;
+    case 2:
+        if (__comp(*--__e2, *__f1))
+        {
+            __node_pointer __f = __e2.__ptr_;
+            base::__unlink_nodes(__f, __f);
+            __link_nodes(__f1.__ptr_, __f, __f);
+            return __e2;
+        }
+        return __f1;
+    }
+    size_type __n2 = __n / 2;
+    iterator __e1 = _VSTD::next(__f1, __n2);
+    iterator  __r = __f1 = __sort(__f1, __e1, __n2, __comp);
+    iterator __f2 = __e1 = __sort(__e1, __e2, __n - __n2, __comp);
+    if (__comp(*__f2, *__f1))
+    {
+        iterator __m2 = _VSTD::next(__f2);
+        for (; __m2 != __e2 && __comp(*__m2, *__f1); ++__m2)
+            ;
+        __node_pointer __f = __f2.__ptr_;
+        __node_pointer __l = __m2.__ptr_->__prev_;
+        __r = __f2;
+        __e1 = __f2 = __m2;
+        base::__unlink_nodes(__f, __l);
+        __m2 = _VSTD::next(__f1);
+        __link_nodes(__f1.__ptr_, __f, __l);
+        __f1 = __m2;
+    }
+    else
+        ++__f1;
+    while (__f1 != __e1 && __f2 != __e2)
+    {
+        if (__comp(*__f2, *__f1))
+        {
+            iterator __m2 = _VSTD::next(__f2);
+            for (; __m2 != __e2 && __comp(*__m2, *__f1); ++__m2)
+                ;
+            __node_pointer __f = __f2.__ptr_;
+            __node_pointer __l = __m2.__ptr_->__prev_;
+            if (__e1 == __f2)
+                __e1 = __m2;
+            __f2 = __m2;
+            base::__unlink_nodes(__f, __l);
+            __m2 = _VSTD::next(__f1);
+            __link_nodes(__f1.__ptr_, __f, __l);
+            __f1 = __m2;
+        }
+        else
+            ++__f1;
+    }
+    return __r;
+}
+
+template <class _Tp, class _Alloc>
+void
+list<_Tp, _Alloc>::reverse() _NOEXCEPT
+{
+    if (base::__sz() > 1)
+    {
+        iterator __e = end();
+        for (iterator __i = begin(); __i.__ptr_ != __e.__ptr_;)
+        {
+            _VSTD::swap(__i.__ptr_->__prev_, __i.__ptr_->__next_);
+            __i.__ptr_ = __i.__ptr_->__prev_;
+        }
+        _VSTD::swap(__e.__ptr_->__prev_, __e.__ptr_->__next_);
+    }
+}
+
+template <class _Tp, class _Alloc>
+bool
+list<_Tp, _Alloc>::__invariants() const
+{
+    return size() == _VSTD::distance(begin(), end());
+}
+
+#if _LIBCPP_DEBUG_LEVEL >= 2
+
+template <class _Tp, class _Alloc>
+bool
+list<_Tp, _Alloc>::__dereferenceable(const const_iterator* __i) const
+{
+    return __i->__ptr_ != static_cast<__node_pointer>(
+                       pointer_traits<__node_base_pointer>::pointer_to(const_cast<__node_base&>(this->__end_)));
+}
+
+template <class _Tp, class _Alloc>
+bool
+list<_Tp, _Alloc>::__decrementable(const const_iterator* __i) const
+{
+    return !empty() &&  __i->__ptr_ != base::__end_.__next_;
+}
+
+template <class _Tp, class _Alloc>
+bool
+list<_Tp, _Alloc>::__addable(const const_iterator* __i, ptrdiff_t __n) const
+{
+    return false;
+}
+
+template <class _Tp, class _Alloc>
+bool
+list<_Tp, _Alloc>::__subscriptable(const const_iterator* __i, ptrdiff_t __n) const
+{
+    return false;
+}
+
+#endif  // _LIBCPP_DEBUG_LEVEL >= 2
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
+{
+    return __x.size() == __y.size() && _VSTD::equal(__x.begin(), __x.end(), __y.begin());
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator< (const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
+{
+    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
+{
+    return !(__x == __y);
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator> (const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
+{
+    return __y < __x;
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
+{
+    return !(__x < __y);
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
+{
+    return !(__y < __x);
+}
+
+template <class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(list<_Tp, _Alloc>& __x, list<_Tp, _Alloc>& __y)
+    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
+{
+    __x.swap(__y);
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_LIST

diff --git a/libcxx/include/locale b/libcxx/include/locale
new file mode 100644
index 0000000..e683ba3
--- /dev/null
+++ b/libcxx/include/locale

@@ -0,0 +1,4472 @@
+// -*- C++ -*-
+//===-------------------------- locale ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_LOCALE
+#define _LIBCPP_LOCALE
+
+/*
+    locale synopsis
+
+namespace std
+{
+
+class locale
+{
+public:
+    // types:
+    class facet;
+    class id;
+
+    typedef int category;
+    static const category // values assigned here are for exposition only
+        none     = 0x000,
+        collate  = 0x010,
+        ctype    = 0x020,
+        monetary = 0x040,
+        numeric  = 0x080,
+        time     = 0x100,
+        messages = 0x200,
+        all = collate | ctype | monetary | numeric | time | messages;
+
+    // construct/copy/destroy:
+    locale() noexcept;
+    locale(const locale& other) noexcept;
+    explicit locale(const char* std_name);
+    explicit locale(const string& std_name);
+    locale(const locale& other, const char* std_name, category);
+    locale(const locale& other, const string& std_name, category);
+    template <class Facet> locale(const locale& other, Facet* f);
+    locale(const locale& other, const locale& one, category);
+
+    ~locale(); // not virtual
+
+    const locale& operator=(const locale& other) noexcept;
+
+    template <class Facet> locale combine(const locale& other) const;
+
+    // locale operations:
+    basic_string<char> name() const;
+    bool operator==(const locale& other) const;
+    bool operator!=(const locale& other) const;
+    template <class charT, class Traits, class Allocator>
+      bool operator()(const basic_string<charT,Traits,Allocator>& s1,
+                      const basic_string<charT,Traits,Allocator>& s2) const;
+
+    // global locale objects:
+    static locale global(const locale&);
+    static const locale& classic();
+};
+
+template <class Facet> const Facet& use_facet(const locale&);
+template <class Facet> bool has_facet(const locale&) noexcept;
+
+// 22.3.3, convenience interfaces:
+template <class charT> bool isspace (charT c, const locale& loc);
+template <class charT> bool isprint (charT c, const locale& loc);
+template <class charT> bool iscntrl (charT c, const locale& loc);
+template <class charT> bool isupper (charT c, const locale& loc);
+template <class charT> bool islower (charT c, const locale& loc);
+template <class charT> bool isalpha (charT c, const locale& loc);
+template <class charT> bool isdigit (charT c, const locale& loc);
+template <class charT> bool ispunct (charT c, const locale& loc);
+template <class charT> bool isxdigit(charT c, const locale& loc);
+template <class charT> bool isalnum (charT c, const locale& loc);
+template <class charT> bool isgraph (charT c, const locale& loc);
+template <class charT> charT toupper(charT c, const locale& loc);
+template <class charT> charT tolower(charT c, const locale& loc);
+
+template<class Codecvt, class Elem = wchar_t,
+         class Wide_alloc = allocator<Elem>,
+         class Byte_alloc = allocator<char>>
+class wstring_convert
+{
+public:
+    typedef basic_string<char, char_traits<char>, Byte_alloc> byte_string;
+    typedef basic_string<Elem, char_traits<Elem>, Wide_alloc> wide_string;
+    typedef typename Codecvt::state_type                      state_type;
+    typedef typename wide_string::traits_type::int_type       int_type;
+
+    explicit wstring_convert(Codecvt* pcvt = new Codecvt);          // explicit in C++14
+    wstring_convert(Codecvt* pcvt, state_type state);
+    explicit wstring_convert(const byte_string& byte_err,           // explicit in C++14
+                    const wide_string& wide_err = wide_string());
+    wstring_convert(const wstring_convert&) = delete;               // C++14
+    wstring_convert & operator=(const wstring_convert &) = delete;  // C++14
+    ~wstring_convert();
+
+    wide_string from_bytes(char byte);
+    wide_string from_bytes(const char* ptr);
+    wide_string from_bytes(const byte_string& str);
+    wide_string from_bytes(const char* first, const char* last);
+
+    byte_string to_bytes(Elem wchar);
+    byte_string to_bytes(const Elem* wptr);
+    byte_string to_bytes(const wide_string& wstr);
+    byte_string to_bytes(const Elem* first, const Elem* last);
+
+    size_t converted() const; // noexcept in C++14
+    state_type state() const;
+};
+
+template <class Codecvt, class Elem = wchar_t, class Tr = char_traits<Elem>>
+class wbuffer_convert
+    : public basic_streambuf<Elem, Tr>
+{
+public:
+    typedef typename Tr::state_type state_type;
+
+    explicit wbuffer_convert(streambuf* bytebuf = 0, Codecvt* pcvt = new Codecvt,
+                    state_type state = state_type());       // explicit in C++14
+    wbuffer_convert(const wbuffer_convert&) = delete;               // C++14
+    wbuffer_convert & operator=(const wbuffer_convert &) = delete;  // C++14
+    ~wbuffer_convert();                                             // C++14
+    
+    streambuf* rdbuf() const;
+    streambuf* rdbuf(streambuf* bytebuf);
+
+    state_type state() const;
+};
+
+// 22.4.1 and 22.4.1.3, ctype:
+class ctype_base;
+template <class charT> class ctype;
+template <> class ctype<char>; // specialization
+template <class charT> class ctype_byname;
+template <> class ctype_byname<char>; // specialization
+
+class codecvt_base;
+template <class internT, class externT, class stateT> class codecvt;
+template <class internT, class externT, class stateT> class codecvt_byname;
+
+// 22.4.2 and 22.4.3, numeric:
+template <class charT, class InputIterator> class num_get;
+template <class charT, class OutputIterator> class num_put;
+template <class charT> class numpunct;
+template <class charT> class numpunct_byname;
+
+// 22.4.4, col lation:
+template <class charT> class collate;
+template <class charT> class collate_byname;
+
+// 22.4.5, date and time:
+class time_base;
+template <class charT, class InputIterator> class time_get;
+template <class charT, class InputIterator> class time_get_byname;
+template <class charT, class OutputIterator> class time_put;
+template <class charT, class OutputIterator> class time_put_byname;
+
+// 22.4.6, money:
+class money_base;
+template <class charT, class InputIterator> class money_get;
+template <class charT, class OutputIterator> class money_put;
+template <class charT, bool Intl> class moneypunct;
+template <class charT, bool Intl> class moneypunct_byname;
+
+// 22.4.7, message retrieval:
+class messages_base;
+template <class charT> class messages;
+template <class charT> class messages_byname;
+
+}  // std
+
+*/
+
+#include <__config>
+#include <__locale>
+#include <algorithm>
+#include <memory>
+#include <ios>
+#include <streambuf>
+#include <iterator>
+#include <limits>
+#ifndef __APPLE__
+#include <cstdarg>
+#endif
+#include <cstdlib>
+#include <ctime>
+#if defined(_LIBCPP_MSVCRT) || defined(__MINGW32__)
+#include <support/win32/locale_win32.h>
+#elif defined(_NEWLIB_VERSION)
+// FIXME: replace all the uses of _NEWLIB_VERSION with __NEWLIB__ preceded by an
+// include of <sys/cdefs.h> once https://sourceware.org/ml/newlib-cvs/2014-q3/msg00038.html
+// has had a chance to bake for a bit
+#include <support/newlib/xlocale.h>
+#endif
+#ifdef _LIBCPP_HAS_CATOPEN
+#include <nl_types.h>
+#endif
+
+#ifdef __APPLE__
+#include <Availability.h>
+#endif
+
+#include <__undef_min_max>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if defined(__APPLE__) || defined(__FreeBSD__)
+#  define _LIBCPP_GET_C_LOCALE 0
+#elif defined(__CloudABI__) || defined(__NetBSD__)
+#  define _LIBCPP_GET_C_LOCALE LC_C_LOCALE
+#else
+#  define _LIBCPP_GET_C_LOCALE __cloc()
+   // Get the C locale object
+   _LIBCPP_FUNC_VIS locale_t __cloc();
+#define __cloc_defined
+#endif
+
+typedef _VSTD::remove_pointer<locale_t>::type __locale_struct;
+typedef _VSTD::unique_ptr<__locale_struct, decltype(&freelocale)> __locale_unique_ptr;
+#ifndef _LIBCPP_LOCALE__L_EXTENSIONS
+typedef _VSTD::unique_ptr<__locale_struct, decltype(&uselocale)> __locale_raii;
+#endif
+
+// OSX has nice foo_l() functions that let you turn off use of the global
+// locale.  Linux, not so much.  The following functions avoid the locale when
+// that's possible and otherwise do the wrong thing.  FIXME.
+#if defined(__linux__) || defined(__EMSCRIPTEN__) || defined(_AIX) || \
+    defined(_NEWLIB_VERSION) || defined(__GLIBC__)
+
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+decltype(MB_CUR_MAX_L(_VSTD::declval<locale_t>()))
+inline _LIBCPP_INLINE_VISIBILITY
+__mb_cur_max_l(locale_t __l)
+{
+  return MB_CUR_MAX_L(__l);
+}
+#else  // _LIBCPP_LOCALE__L_EXTENSIONS
+inline _LIBCPP_ALWAYS_INLINE
+decltype(MB_CUR_MAX) __mb_cur_max_l(locale_t __l)
+{
+  __locale_raii __current(uselocale(__l), uselocale);
+  return MB_CUR_MAX;
+}
+#endif // _LIBCPP_LOCALE__L_EXTENSIONS
+
+inline _LIBCPP_ALWAYS_INLINE
+wint_t __btowc_l(int __c, locale_t __l)
+{
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+  return btowc_l(__c, __l);
+#else
+  __locale_raii __current(uselocale(__l), uselocale);
+  return btowc(__c);
+#endif
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+int __wctob_l(wint_t __c, locale_t __l)
+{
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+  return wctob_l(__c, __l);
+#else
+  __locale_raii __current(uselocale(__l), uselocale);
+  return wctob(__c);
+#endif
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+size_t __wcsnrtombs_l(char *__dest, const wchar_t **__src, size_t __nwc,
+                      size_t __len, mbstate_t *__ps, locale_t __l)
+{
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+  return wcsnrtombs_l(__dest, __src, __nwc, __len, __ps, __l);
+#else
+  __locale_raii __current(uselocale(__l), uselocale);
+  return wcsnrtombs(__dest, __src, __nwc, __len, __ps);
+#endif
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+size_t __wcrtomb_l(char *__s, wchar_t __wc, mbstate_t *__ps, locale_t __l)
+{
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+  return wcrtomb_l(__s, __wc, __ps, __l);
+#else
+  __locale_raii __current(uselocale(__l), uselocale);
+  return wcrtomb(__s, __wc, __ps);
+#endif
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+size_t __mbsnrtowcs_l(wchar_t * __dest, const char **__src, size_t __nms,
+                      size_t __len, mbstate_t *__ps, locale_t __l)
+{
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+  return mbsnrtowcs_l(__dest, __src, __nms, __len, __ps, __l);
+#else
+  __locale_raii __current(uselocale(__l), uselocale);
+  return mbsnrtowcs(__dest, __src, __nms, __len, __ps);
+#endif
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+size_t __mbrtowc_l(wchar_t *__pwc, const char *__s, size_t __n,
+                   mbstate_t *__ps, locale_t __l)
+{
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+  return mbrtowc_l(__pwc, __s, __n, __ps, __l);
+#else
+  __locale_raii __current(uselocale(__l), uselocale);
+  return mbrtowc(__pwc, __s, __n, __ps);
+#endif
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+int __mbtowc_l(wchar_t *__pwc, const char *__pmb, size_t __max, locale_t __l)
+{
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+  return mbtowc_l(__pwc, __pmb, __max, __l);
+#else
+  __locale_raii __current(uselocale(__l), uselocale);
+  return mbtowc(__pwc, __pmb, __max);
+#endif
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+size_t __mbrlen_l(const char *__s, size_t __n, mbstate_t *__ps, locale_t __l)
+{
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+  return mbrlen_l(__s, __n, __ps, __l);
+#else
+  __locale_raii __current(uselocale(__l), uselocale);
+  return mbrlen(__s, __n, __ps);
+#endif
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+lconv *__localeconv_l(locale_t __l)
+{
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+  return localeconv_l(__l);
+#else
+  __locale_raii __current(uselocale(__l), uselocale);
+  return localeconv();
+#endif
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+size_t __mbsrtowcs_l(wchar_t *__dest, const char **__src, size_t __len,
+                     mbstate_t *__ps, locale_t __l)
+{
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+  return mbsrtowcs_l(__dest, __src, __len, __ps, __l);
+#else
+  __locale_raii __current(uselocale(__l), uselocale);
+  return mbsrtowcs(__dest, __src, __len, __ps);
+#endif
+}
+
+inline
+int __snprintf_l(char *__s, size_t __n, locale_t __l, const char *__format, ...) {
+  va_list __va;
+  va_start(__va, __format);
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+  int __res = vsnprintf_l(__s, __n, __l, __format, __va);
+#else
+  __locale_raii __current(uselocale(__l), uselocale);
+  int __res = vsnprintf(__s, __n, __format, __va);
+#endif
+  va_end(__va);
+  return __res;
+}
+
+inline
+int __asprintf_l(char **__s, locale_t __l, const char *__format, ...) {
+  va_list __va;
+  va_start(__va, __format);
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+  int __res = vasprintf_l(__s, __l, __format, __va);
+#else
+  __locale_raii __current(uselocale(__l), uselocale);
+  int __res = vasprintf(__s, __format, __va);
+#endif
+  va_end(__va);
+  return __res;
+}
+
+inline
+int __sscanf_l(const char *__s, locale_t __l, const char *__format, ...) {
+  va_list __va;
+  va_start(__va, __format);
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+  int __res = vsscanf_l(__s, __l, __format, __va);
+#else
+  __locale_raii __current(uselocale(__l), uselocale);
+  int __res = vsscanf(__s, __format, __va);
+#endif
+  va_end(__va);
+  return __res;
+}
+
+#endif  // __linux__
+
+// __scan_keyword
+// Scans [__b, __e) until a match is found in the basic_strings range
+//  [__kb, __ke) or until it can be shown that there is no match in [__kb, __ke).
+//  __b will be incremented (visibly), consuming CharT until a match is found
+//  or proved to not exist.  A keyword may be "", in which will match anything.
+//  If one keyword is a prefix of another, and the next CharT in the input
+//  might match another keyword, the algorithm will attempt to find the longest
+//  matching keyword.  If the longer matching keyword ends up not matching, then
+//  no keyword match is found.  If no keyword match is found, __ke is returned
+//  and failbit is set in __err.
+//  Else an iterator pointing to the matching keyword is found.  If more than
+//  one keyword matches, an iterator to the first matching keyword is returned.
+//  If on exit __b == __e, eofbit is set in __err.  If __case_sensitive is false,
+//  __ct is used to force to lower case before comparing characters.
+//  Examples:
+//  Keywords:  "a", "abb"
+//  If the input is "a", the first keyword matches and eofbit is set.
+//  If the input is "abc", no match is found and "ab" are consumed.
+template <class _InputIterator, class _ForwardIterator, class _Ctype>
+_LIBCPP_HIDDEN
+_ForwardIterator
+__scan_keyword(_InputIterator& __b, _InputIterator __e,
+               _ForwardIterator __kb, _ForwardIterator __ke,
+               const _Ctype& __ct, ios_base::iostate& __err,
+               bool __case_sensitive = true)
+{
+    typedef typename iterator_traits<_InputIterator>::value_type _CharT;
+    size_t __nkw = static_cast<size_t>(_VSTD::distance(__kb, __ke));
+    const unsigned char __doesnt_match = '\0';
+    const unsigned char __might_match = '\1';
+    const unsigned char __does_match = '\2';
+    unsigned char __statbuf[100];
+    unsigned char* __status = __statbuf;
+    unique_ptr<unsigned char, void(*)(void*)> __stat_hold(0, free);
+    if (__nkw > sizeof(__statbuf))
+    {
+        __status = (unsigned char*)malloc(__nkw);
+        if (__status == 0)
+            __throw_bad_alloc();
+        __stat_hold.reset(__status);
+    }
+    size_t __n_might_match = __nkw;  // At this point, any keyword might match
+    size_t __n_does_match = 0;       // but none of them definitely do
+    // Initialize all statuses to __might_match, except for "" keywords are __does_match
+    unsigned char* __st = __status;
+    for (_ForwardIterator __ky = __kb; __ky != __ke; ++__ky, (void) ++__st)
+    {
+        if (!__ky->empty())
+            *__st = __might_match;
+        else
+        {
+            *__st = __does_match;
+            --__n_might_match;
+            ++__n_does_match;
+        }
+    }
+    // While there might be a match, test keywords against the next CharT
+    for (size_t __indx = 0; __b != __e && __n_might_match > 0; ++__indx)
+    {
+        // Peek at the next CharT but don't consume it
+        _CharT __c = *__b;
+        if (!__case_sensitive)
+            __c = __ct.toupper(__c);
+        bool __consume = false;
+        // For each keyword which might match, see if the __indx character is __c
+        // If a match if found, consume __c
+        // If a match is found, and that is the last character in the keyword,
+        //    then that keyword matches.
+        // If the keyword doesn't match this character, then change the keyword
+        //    to doesn't match
+        __st = __status;
+        for (_ForwardIterator __ky = __kb; __ky != __ke; ++__ky, (void) ++__st)
+        {
+            if (*__st == __might_match)
+            {
+                _CharT __kc = (*__ky)[__indx];
+                if (!__case_sensitive)
+                    __kc = __ct.toupper(__kc);
+                if (__c == __kc)
+                {
+                    __consume = true;
+                    if (__ky->size() == __indx+1)
+                    {
+                        *__st = __does_match;
+                        --__n_might_match;
+                        ++__n_does_match;
+                    }
+                }
+                else
+                {
+                    *__st = __doesnt_match;
+                    --__n_might_match;
+                }
+            }
+        }
+        // consume if we matched a character
+        if (__consume)
+        {
+            ++__b;
+            // If we consumed a character and there might be a matched keyword that
+            //   was marked matched on a previous iteration, then such keywords
+            //   which are now marked as not matching.
+            if (__n_might_match + __n_does_match > 1)
+            {
+                __st = __status;
+                for (_ForwardIterator __ky = __kb; __ky != __ke; ++__ky, (void) ++__st)
+                {
+                    if (*__st == __does_match && __ky->size() != __indx+1)
+                    {
+                        *__st = __doesnt_match;
+                        --__n_does_match;
+                    }
+                }
+            }
+        }
+    }
+    // We've exited the loop because we hit eof and/or we have no more "might matches".
+    if (__b == __e)
+        __err |= ios_base::eofbit;
+    // Return the first matching result
+    for (__st = __status; __kb != __ke; ++__kb, (void) ++__st)
+        if (*__st == __does_match)
+            break;
+    if (__kb == __ke)
+        __err |= ios_base::failbit;
+    return __kb;
+}
+
+struct _LIBCPP_TYPE_VIS __num_get_base
+{
+    static const int __num_get_buf_sz = 40;
+
+    static int __get_base(ios_base&);
+    static const char __src[33];
+};
+
+_LIBCPP_FUNC_VIS
+void __check_grouping(const string& __grouping, unsigned* __g, unsigned* __g_end,
+                      ios_base::iostate& __err);
+
+template <class _CharT>
+struct __num_get
+    : protected __num_get_base
+{
+    static string __stage2_int_prep(ios_base& __iob, _CharT* __atoms, _CharT& __thousands_sep);
+    static string __stage2_float_prep(ios_base& __iob, _CharT* __atoms, _CharT& __decimal_point,
+                                      _CharT& __thousands_sep);
+    static int __stage2_int_loop(_CharT __ct, int __base, char* __a, char*& __a_end,
+                  unsigned& __dc, _CharT __thousands_sep, const string& __grouping,
+                  unsigned* __g, unsigned*& __g_end, _CharT* __atoms);
+    static int __stage2_float_loop(_CharT __ct, bool& __in_units, char& __exp,
+                                   char* __a, char*& __a_end,
+                                   _CharT __decimal_point, _CharT __thousands_sep,
+                                   const string& __grouping, unsigned* __g,
+                                   unsigned*& __g_end, unsigned& __dc, _CharT* __atoms);
+};
+
+template <class _CharT>
+string
+__num_get<_CharT>::__stage2_int_prep(ios_base& __iob, _CharT* __atoms, _CharT& __thousands_sep)
+{
+    locale __loc = __iob.getloc();
+    use_facet<ctype<_CharT> >(__loc).widen(__src, __src + 26, __atoms);
+    const numpunct<_CharT>& __np = use_facet<numpunct<_CharT> >(__loc);
+    __thousands_sep = __np.thousands_sep();
+    return __np.grouping();
+}
+
+template <class _CharT>
+string
+__num_get<_CharT>::__stage2_float_prep(ios_base& __iob, _CharT* __atoms, _CharT& __decimal_point,
+                    _CharT& __thousands_sep)
+{
+    locale __loc = __iob.getloc();
+    use_facet<ctype<_CharT> >(__loc).widen(__src, __src + 32, __atoms);
+    const numpunct<_CharT>& __np = use_facet<numpunct<_CharT> >(__loc);
+    __decimal_point = __np.decimal_point();
+    __thousands_sep = __np.thousands_sep();
+    return __np.grouping();
+}
+
+template <class _CharT>
+int
+__num_get<_CharT>::__stage2_int_loop(_CharT __ct, int __base, char* __a, char*& __a_end,
+                  unsigned& __dc, _CharT __thousands_sep, const string& __grouping,
+                  unsigned* __g, unsigned*& __g_end, _CharT* __atoms)
+{
+    if (__a_end == __a && (__ct == __atoms[24] || __ct == __atoms[25]))
+    {
+        *__a_end++ = __ct == __atoms[24] ? '+' : '-';
+        __dc = 0;
+        return 0;
+    }
+    if (__grouping.size() != 0 && __ct == __thousands_sep)
+    {
+        if (__g_end-__g < __num_get_buf_sz)
+        {
+            *__g_end++ = __dc;
+            __dc = 0;
+        }
+        return 0;
+    }
+    ptrdiff_t __f = find(__atoms, __atoms + 26, __ct) - __atoms;
+    if (__f >= 24)
+        return -1;
+    switch (__base)
+    {
+    case 8:
+    case 10:
+        if (__f >= __base)
+            return -1;
+        break;
+    case 16:
+        if (__f < 22)
+            break;
+        if (__a_end != __a && __a_end - __a <= 2 && __a_end[-1] == '0')
+        {
+            __dc = 0;
+            *__a_end++ = __src[__f];
+            return 0;
+        }
+        return -1;
+    }
+    *__a_end++ = __src[__f];
+    ++__dc;
+    return 0;
+}
+
+template <class _CharT>
+int
+__num_get<_CharT>::__stage2_float_loop(_CharT __ct, bool& __in_units, char& __exp, char* __a, char*& __a_end,
+                    _CharT __decimal_point, _CharT __thousands_sep, const string& __grouping,
+                    unsigned* __g, unsigned*& __g_end, unsigned& __dc, _CharT* __atoms)
+{
+    if (__ct == __decimal_point)
+    {
+        if (!__in_units)
+            return -1;
+        __in_units = false;
+        *__a_end++ = '.';
+        if (__grouping.size() != 0 && __g_end-__g < __num_get_buf_sz)
+            *__g_end++ = __dc;
+        return 0;
+    }
+    if (__ct == __thousands_sep && __grouping.size() != 0)
+    {
+        if (!__in_units)
+            return -1;
+        if (__g_end-__g < __num_get_buf_sz)
+        {
+            *__g_end++ = __dc;
+            __dc = 0;
+        }
+        return 0;
+    }
+    ptrdiff_t __f = find(__atoms, __atoms + 32, __ct) - __atoms;
+    if (__f >= 32)
+        return -1;
+    char __x = __src[__f];
+    if (__x == '-' || __x == '+')
+    {
+        if (__a_end == __a || (__a_end[-1] & 0x5F) == (__exp & 0x7F))
+        {
+            *__a_end++ = __x;
+            return 0;
+        }
+        return -1;
+    }
+    if (__x == 'x' || __x == 'X')
+        __exp = 'P';
+    else if ((__x & 0x5F) == __exp)
+    {
+        __exp |= 0x80;
+        if (__in_units)
+        {
+            __in_units = false;
+            if (__grouping.size() != 0 && __g_end-__g < __num_get_buf_sz)
+                *__g_end++ = __dc;
+        }
+    }
+    *__a_end++ = __x;
+    if (__f >= 22)
+        return 0;
+    ++__dc;
+    return 0;
+}
+
+_LIBCPP_EXTERN_TEMPLATE2(struct _LIBCPP_TYPE_VIS __num_get<char>)
+_LIBCPP_EXTERN_TEMPLATE2(struct _LIBCPP_TYPE_VIS __num_get<wchar_t>)
+
+template <class _CharT, class _InputIterator = istreambuf_iterator<_CharT> >
+class _LIBCPP_TYPE_VIS_ONLY num_get
+    : public locale::facet,
+      private __num_get<_CharT>
+{
+public:
+    typedef _CharT char_type;
+    typedef _InputIterator iter_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit num_get(size_t __refs = 0)
+        : locale::facet(__refs) {}
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
+                  ios_base::iostate& __err, bool& __v) const
+    {
+        return do_get(__b, __e, __iob, __err, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
+                  ios_base::iostate& __err, long& __v) const
+    {
+        return do_get(__b, __e, __iob, __err, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
+                  ios_base::iostate& __err, long long& __v) const
+    {
+        return do_get(__b, __e, __iob, __err, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
+                  ios_base::iostate& __err, unsigned short& __v) const
+    {
+        return do_get(__b, __e, __iob, __err, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
+                  ios_base::iostate& __err, unsigned int& __v) const
+    {
+        return do_get(__b, __e, __iob, __err, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
+                  ios_base::iostate& __err, unsigned long& __v) const
+    {
+        return do_get(__b, __e, __iob, __err, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
+                  ios_base::iostate& __err, unsigned long long& __v) const
+    {
+        return do_get(__b, __e, __iob, __err, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
+                  ios_base::iostate& __err, float& __v) const
+    {
+        return do_get(__b, __e, __iob, __err, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
+                  ios_base::iostate& __err, double& __v) const
+    {
+        return do_get(__b, __e, __iob, __err, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
+                  ios_base::iostate& __err, long double& __v) const
+    {
+        return do_get(__b, __e, __iob, __err, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
+                  ios_base::iostate& __err, void*& __v) const
+    {
+        return do_get(__b, __e, __iob, __err, __v);
+    }
+
+    static locale::id id;
+
+protected:
+    _LIBCPP_ALWAYS_INLINE
+    ~num_get() {}
+
+    template <class _Fp>
+    iter_type __do_get_floating_point
+                            (iter_type __b, iter_type __e, ios_base& __iob,
+                             ios_base::iostate& __err, _Fp& __v) const;
+
+    template <class _Signed>
+    iter_type __do_get_signed
+                            (iter_type __b, iter_type __e, ios_base& __iob,
+                             ios_base::iostate& __err, _Signed& __v) const;
+
+    template <class _Unsigned>
+    iter_type __do_get_unsigned
+                            (iter_type __b, iter_type __e, ios_base& __iob,
+                             ios_base::iostate& __err, _Unsigned& __v) const;
+
+
+    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
+                             ios_base::iostate& __err, bool& __v) const;
+
+    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
+                             ios_base::iostate& __err, long& __v) const
+    { return this->__do_get_signed ( __b, __e, __iob, __err, __v ); }
+
+    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
+                             ios_base::iostate& __err, long long& __v) const
+    { return this->__do_get_signed ( __b, __e, __iob, __err, __v ); }
+
+    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
+                             ios_base::iostate& __err, unsigned short& __v) const
+    { return this->__do_get_unsigned ( __b, __e, __iob, __err, __v ); }
+
+    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
+                             ios_base::iostate& __err, unsigned int& __v) const
+    { return this->__do_get_unsigned ( __b, __e, __iob, __err, __v ); }
+
+    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
+                             ios_base::iostate& __err, unsigned long& __v) const
+    { return this->__do_get_unsigned ( __b, __e, __iob, __err, __v ); }
+
+    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
+                             ios_base::iostate& __err, unsigned long long& __v) const
+    { return this->__do_get_unsigned ( __b, __e, __iob, __err, __v ); }
+
+    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
+                             ios_base::iostate& __err, float& __v) const
+    { return this->__do_get_floating_point ( __b, __e, __iob, __err, __v ); }
+
+    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
+                             ios_base::iostate& __err, double& __v) const
+    { return this->__do_get_floating_point ( __b, __e, __iob, __err, __v ); }
+
+    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
+                             ios_base::iostate& __err, long double& __v) const
+    { return this->__do_get_floating_point ( __b, __e, __iob, __err, __v ); }
+
+    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
+                             ios_base::iostate& __err, void*& __v) const;
+};
+
+template <class _CharT, class _InputIterator>
+locale::id
+num_get<_CharT, _InputIterator>::id;
+
+template <class _Tp>
+_Tp
+__num_get_signed_integral(const char* __a, const char* __a_end,
+                          ios_base::iostate& __err, int __base)
+{
+    if (__a != __a_end)
+    {
+        typename remove_reference<decltype(errno)>::type __save_errno = errno;
+        errno = 0;
+        char *__p2;
+        long long __ll = strtoll_l(__a, &__p2, __base, _LIBCPP_GET_C_LOCALE);
+        typename remove_reference<decltype(errno)>::type __current_errno = errno;
+        if (__current_errno == 0)
+            errno = __save_errno;
+        if (__p2 != __a_end)
+        {
+            __err = ios_base::failbit;
+            return 0;
+        }
+        else if (__current_errno == ERANGE         ||
+                 __ll < numeric_limits<_Tp>::min() ||
+                 numeric_limits<_Tp>::max() < __ll)
+        {
+            __err = ios_base::failbit;
+            if (__ll > 0)
+                return numeric_limits<_Tp>::max();
+            else
+                return numeric_limits<_Tp>::min();
+        }
+        return static_cast<_Tp>(__ll);
+    }
+    __err = ios_base::failbit;
+    return 0;
+}
+
+template <class _Tp>
+_Tp
+__num_get_unsigned_integral(const char* __a, const char* __a_end,
+                            ios_base::iostate& __err, int __base)
+{
+    if (__a != __a_end)
+    {
+        if (*__a == '-')
+        {
+            __err = ios_base::failbit;
+            return 0;
+        }
+        typename remove_reference<decltype(errno)>::type __save_errno = errno;
+        errno = 0;
+        char *__p2;
+        unsigned long long __ll = strtoull_l(__a, &__p2, __base, _LIBCPP_GET_C_LOCALE);
+        typename remove_reference<decltype(errno)>::type __current_errno = errno;
+        if (__current_errno == 0)
+            errno = __save_errno;
+        if (__p2 != __a_end)
+        {
+            __err = ios_base::failbit;
+            return 0;
+        }
+        else if (__current_errno == ERANGE ||
+                 numeric_limits<_Tp>::max() < __ll)
+        {
+            __err = ios_base::failbit;
+            return numeric_limits<_Tp>::max();
+        }
+        return static_cast<_Tp>(__ll);
+    }
+    __err = ios_base::failbit;
+    return 0;
+}
+
+template <class _Tp>
+_Tp
+__num_get_float(const char* __a, const char* __a_end, ios_base::iostate& __err)
+{
+    if (__a != __a_end)
+    {
+        typename remove_reference<decltype(errno)>::type __save_errno = errno;
+        errno = 0;
+        char *__p2;
+        long double __ld = strtold_l(__a, &__p2, _LIBCPP_GET_C_LOCALE);
+        typename remove_reference<decltype(errno)>::type __current_errno = errno;
+        if (__current_errno == 0)
+            errno = __save_errno;
+        if (__p2 != __a_end)
+        {
+            __err = ios_base::failbit;
+            return 0;
+        }
+        else if (__current_errno == ERANGE)
+            __err = ios_base::failbit;
+        return static_cast<_Tp>(__ld);
+    }
+    __err = ios_base::failbit;
+    return 0;
+}
+
+template <class _CharT, class _InputIterator>
+_InputIterator
+num_get<_CharT, _InputIterator>::do_get(iter_type __b, iter_type __e,
+                                        ios_base& __iob,
+                                        ios_base::iostate& __err,
+                                        bool& __v) const
+{
+    if ((__iob.flags() & ios_base::boolalpha) == 0)
+    {
+        long __lv = -1;
+        __b = do_get(__b, __e, __iob, __err, __lv);
+        switch (__lv)
+        {
+        case 0:
+            __v = false;
+            break;
+        case 1:
+            __v = true;
+            break;
+        default:
+            __v = true;
+            __err = ios_base::failbit;
+            break;
+        }
+        return __b;
+    }
+    const ctype<_CharT>& __ct = use_facet<ctype<_CharT> >(__iob.getloc());
+    const numpunct<_CharT>& __np = use_facet<numpunct<_CharT> >(__iob.getloc());
+    typedef typename numpunct<_CharT>::string_type string_type;
+    const string_type __names[2] = {__np.truename(), __np.falsename()};
+    const string_type* __i = __scan_keyword(__b, __e, __names, __names+2,
+                                            __ct, __err);
+    __v = __i == __names;
+    return __b;
+}
+
+// signed
+
+template <class _CharT, class _InputIterator>
+template <class _Signed>
+_InputIterator
+num_get<_CharT, _InputIterator>::__do_get_signed(iter_type __b, iter_type __e,
+                                        ios_base& __iob,
+                                        ios_base::iostate& __err,
+                                        _Signed& __v) const
+{
+    // Stage 1
+    int __base = this->__get_base(__iob);
+    // Stage 2
+    char_type __atoms[26];
+    char_type __thousands_sep;
+    string __grouping = this->__stage2_int_prep(__iob, __atoms, __thousands_sep);
+    string __buf;
+    __buf.resize(__buf.capacity());
+    char* __a = &__buf[0];
+    char* __a_end = __a;
+    unsigned __g[__num_get_base::__num_get_buf_sz];
+    unsigned* __g_end = __g;
+    unsigned __dc = 0;
+    for (; __b != __e; ++__b)
+    {
+        if (__a_end == __a + __buf.size())
+        {
+            size_t __tmp = __buf.size();
+            __buf.resize(2*__buf.size());
+            __buf.resize(__buf.capacity());
+            __a = &__buf[0];
+            __a_end = __a + __tmp;
+        }
+        if (this->__stage2_int_loop(*__b, __base, __a, __a_end, __dc,
+                                    __thousands_sep, __grouping, __g, __g_end,
+                                    __atoms))
+            break;
+    }
+    if (__grouping.size() != 0 && __g_end-__g < __num_get_base::__num_get_buf_sz)
+        *__g_end++ = __dc;
+    // Stage 3
+    __v = __num_get_signed_integral<_Signed>(__a, __a_end, __err, __base);
+    // Digit grouping checked
+    __check_grouping(__grouping, __g, __g_end, __err);
+    // EOF checked
+    if (__b == __e)
+        __err |= ios_base::eofbit;
+    return __b;
+}
+
+// unsigned
+
+template <class _CharT, class _InputIterator>
+template <class _Unsigned>
+_InputIterator
+num_get<_CharT, _InputIterator>::__do_get_unsigned(iter_type __b, iter_type __e,
+                                        ios_base& __iob,
+                                        ios_base::iostate& __err,
+                                        _Unsigned& __v) const
+{
+    // Stage 1
+    int __base = this->__get_base(__iob);
+    // Stage 2
+    char_type __atoms[26];
+    char_type __thousands_sep;
+    string __grouping = this->__stage2_int_prep(__iob, __atoms, __thousands_sep);
+    string __buf;
+    __buf.resize(__buf.capacity());
+    char* __a = &__buf[0];
+    char* __a_end = __a;
+    unsigned __g[__num_get_base::__num_get_buf_sz];
+    unsigned* __g_end = __g;
+    unsigned __dc = 0;
+    for (; __b != __e; ++__b)
+    {
+        if (__a_end == __a + __buf.size())
+        {
+            size_t __tmp = __buf.size();
+            __buf.resize(2*__buf.size());
+            __buf.resize(__buf.capacity());
+            __a = &__buf[0];
+            __a_end = __a + __tmp;
+        }
+        if (this->__stage2_int_loop(*__b, __base, __a, __a_end, __dc,
+                                    __thousands_sep, __grouping, __g, __g_end,
+                                    __atoms))
+            break;
+    }
+    if (__grouping.size() != 0 && __g_end-__g < __num_get_base::__num_get_buf_sz)
+        *__g_end++ = __dc;
+    // Stage 3
+    __v = __num_get_unsigned_integral<_Unsigned>(__a, __a_end, __err, __base);
+    // Digit grouping checked
+    __check_grouping(__grouping, __g, __g_end, __err);
+    // EOF checked
+    if (__b == __e)
+        __err |= ios_base::eofbit;
+    return __b;
+}
+
+// floating point
+
+template <class _CharT, class _InputIterator>
+template <class _Fp>
+_InputIterator
+num_get<_CharT, _InputIterator>::__do_get_floating_point(iter_type __b, iter_type __e,
+                                        ios_base& __iob,
+                                        ios_base::iostate& __err,
+                                        _Fp& __v) const
+{
+    // Stage 1, nothing to do
+    // Stage 2
+    char_type __atoms[32];
+    char_type __decimal_point;
+    char_type __thousands_sep;
+    string __grouping = this->__stage2_float_prep(__iob, __atoms,
+                                                  __decimal_point,
+                                                  __thousands_sep);
+    string __buf;
+    __buf.resize(__buf.capacity());
+    char* __a = &__buf[0];
+    char* __a_end = __a;
+    unsigned __g[__num_get_base::__num_get_buf_sz];
+    unsigned* __g_end = __g;
+    unsigned __dc = 0;
+    bool __in_units = true;
+    char __exp = 'E';
+    for (; __b != __e; ++__b)
+    {
+        if (__a_end == __a + __buf.size())
+        {
+            size_t __tmp = __buf.size();
+            __buf.resize(2*__buf.size());
+            __buf.resize(__buf.capacity());
+            __a = &__buf[0];
+            __a_end = __a + __tmp;
+        }
+        if (this->__stage2_float_loop(*__b, __in_units, __exp, __a, __a_end,
+                                      __decimal_point, __thousands_sep,
+                                      __grouping, __g, __g_end,
+                                      __dc, __atoms))
+            break;
+    }
+    if (__grouping.size() != 0 && __in_units && __g_end-__g < __num_get_base::__num_get_buf_sz)
+        *__g_end++ = __dc;
+    // Stage 3
+    __v = __num_get_float<_Fp>(__a, __a_end, __err);
+    // Digit grouping checked
+    __check_grouping(__grouping, __g, __g_end, __err);
+    // EOF checked
+    if (__b == __e)
+        __err |= ios_base::eofbit;
+    return __b;
+}
+
+template <class _CharT, class _InputIterator>
+_InputIterator
+num_get<_CharT, _InputIterator>::do_get(iter_type __b, iter_type __e,
+                                        ios_base& __iob,
+                                        ios_base::iostate& __err,
+                                        void*& __v) const
+{
+    // Stage 1
+    int __base = 16;
+    // Stage 2
+    char_type __atoms[26];
+    char_type __thousands_sep = 0;
+    string __grouping;
+    use_facet<ctype<_CharT> >(__iob.getloc()).widen(__num_get_base::__src,
+                                                    __num_get_base::__src + 26, __atoms);
+    string __buf;
+    __buf.resize(__buf.capacity());
+    char* __a = &__buf[0];
+    char* __a_end = __a;
+    unsigned __g[__num_get_base::__num_get_buf_sz];
+    unsigned* __g_end = __g;
+    unsigned __dc = 0;
+    for (; __b != __e; ++__b)
+    {
+        if (__a_end == __a + __buf.size())
+        {
+            size_t __tmp = __buf.size();
+            __buf.resize(2*__buf.size());
+            __buf.resize(__buf.capacity());
+            __a = &__buf[0];
+            __a_end = __a + __tmp;
+        }
+        if (this->__stage2_int_loop(*__b, __base, __a, __a_end, __dc,
+                                    __thousands_sep, __grouping,
+                                    __g, __g_end, __atoms))
+            break;
+    }
+    // Stage 3
+    __buf.resize(__a_end - __a);
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+    if (sscanf_l(__buf.c_str(), _LIBCPP_GET_C_LOCALE, "%p", &__v) != 1)
+#else
+    if (__sscanf_l(__buf.c_str(), _LIBCPP_GET_C_LOCALE, "%p", &__v) != 1)
+#endif
+        __err = ios_base::failbit;
+    // EOF checked
+    if (__b == __e)
+        __err |= ios_base::eofbit;
+    return __b;
+}
+
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS num_get<char>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS num_get<wchar_t>)
+
+struct _LIBCPP_TYPE_VIS __num_put_base
+{
+protected:
+    static void __format_int(char* __fmt, const char* __len, bool __signd,
+                             ios_base::fmtflags __flags);
+    static bool __format_float(char* __fmt, const char* __len,
+                               ios_base::fmtflags __flags);
+    static char* __identify_padding(char* __nb, char* __ne,
+                                    const ios_base& __iob);
+};
+
+template <class _CharT>
+struct __num_put
+    : protected __num_put_base
+{
+    static void __widen_and_group_int(char* __nb, char* __np, char* __ne,
+                                      _CharT* __ob, _CharT*& __op, _CharT*& __oe,
+                                      const locale& __loc);
+    static void __widen_and_group_float(char* __nb, char* __np, char* __ne,
+                                        _CharT* __ob, _CharT*& __op, _CharT*& __oe,
+                                        const locale& __loc);
+};
+
+template <class _CharT>
+void
+__num_put<_CharT>::__widen_and_group_int(char* __nb, char* __np, char* __ne,
+                                         _CharT* __ob, _CharT*& __op, _CharT*& __oe,
+                                         const locale& __loc)
+{
+    const ctype<_CharT>&    __ct = use_facet<ctype<_CharT> >   (__loc);
+    const numpunct<_CharT>& __npt = use_facet<numpunct<_CharT> >(__loc);
+    string __grouping = __npt.grouping();
+    if (__grouping.empty())
+    {
+        __ct.widen(__nb, __ne, __ob);
+        __oe = __ob + (__ne - __nb);
+    }
+    else
+    {
+        __oe = __ob;
+        char* __nf = __nb;
+        if (*__nf == '-' || *__nf == '+')
+            *__oe++ = __ct.widen(*__nf++);
+        if (__ne - __nf >= 2 && __nf[0] == '0' && (__nf[1] == 'x' ||
+                                                   __nf[1] == 'X'))
+        {
+            *__oe++ = __ct.widen(*__nf++);
+            *__oe++ = __ct.widen(*__nf++);
+        }
+        reverse(__nf, __ne);
+        _CharT __thousands_sep = __npt.thousands_sep();
+        unsigned __dc = 0;
+        unsigned __dg = 0;
+        for (char* __p = __nf; __p < __ne; ++__p)
+        {
+            if (static_cast<unsigned>(__grouping[__dg]) > 0 &&
+                __dc == static_cast<unsigned>(__grouping[__dg]))
+            {
+                *__oe++ = __thousands_sep;
+                __dc = 0;
+                if (__dg < __grouping.size()-1)
+                    ++__dg;
+            }
+            *__oe++ = __ct.widen(*__p);
+            ++__dc;
+        }
+        reverse(__ob + (__nf - __nb), __oe);
+    }
+    if (__np == __ne)
+        __op = __oe;
+    else
+        __op = __ob + (__np - __nb);
+}
+
+template <class _CharT>
+void
+__num_put<_CharT>::__widen_and_group_float(char* __nb, char* __np, char* __ne,
+                                           _CharT* __ob, _CharT*& __op, _CharT*& __oe,
+                                           const locale& __loc)
+{
+    const ctype<_CharT>&    __ct = use_facet<ctype<_CharT> >   (__loc);
+    const numpunct<_CharT>& __npt = use_facet<numpunct<_CharT> >(__loc);
+    string __grouping = __npt.grouping();
+    __oe = __ob;
+    char* __nf = __nb;
+    if (*__nf == '-' || *__nf == '+')
+        *__oe++ = __ct.widen(*__nf++);
+    char* __ns;
+    if (__ne - __nf >= 2 && __nf[0] == '0' && (__nf[1] == 'x' ||
+                                               __nf[1] == 'X'))
+    {
+        *__oe++ = __ct.widen(*__nf++);
+        *__oe++ = __ct.widen(*__nf++);
+        for (__ns = __nf; __ns < __ne; ++__ns)
+            if (!isxdigit_l(*__ns, _LIBCPP_GET_C_LOCALE))
+                break;
+    }
+    else
+    {
+        for (__ns = __nf; __ns < __ne; ++__ns)
+            if (!isdigit_l(*__ns, _LIBCPP_GET_C_LOCALE))
+                break;
+    }
+    if (__grouping.empty())
+    {
+        __ct.widen(__nf, __ns, __oe);
+        __oe += __ns - __nf;
+    }
+    else
+    {
+        reverse(__nf, __ns);
+        _CharT __thousands_sep = __npt.thousands_sep();
+        unsigned __dc = 0;
+        unsigned __dg = 0;
+        for (char* __p = __nf; __p < __ns; ++__p)
+        {
+            if (__grouping[__dg] > 0 && __dc == static_cast<unsigned>(__grouping[__dg]))
+            {
+                *__oe++ = __thousands_sep;
+                __dc = 0;
+                if (__dg < __grouping.size()-1)
+                    ++__dg;
+            }
+            *__oe++ = __ct.widen(*__p);
+            ++__dc;
+        }
+        reverse(__ob + (__nf - __nb), __oe);
+    }
+    for (__nf = __ns; __nf < __ne; ++__nf)
+    {
+        if (*__nf == '.')
+        {
+            *__oe++ = __npt.decimal_point();
+            ++__nf;
+            break;
+        }
+        else
+            *__oe++ = __ct.widen(*__nf);
+    }
+    __ct.widen(__nf, __ne, __oe);
+    __oe += __ne - __nf;
+    if (__np == __ne)
+        __op = __oe;
+    else
+        __op = __ob + (__np - __nb);
+}
+
+_LIBCPP_EXTERN_TEMPLATE2(struct _LIBCPP_TYPE_VIS __num_put<char>)
+_LIBCPP_EXTERN_TEMPLATE2(struct _LIBCPP_TYPE_VIS __num_put<wchar_t>)
+
+template <class _CharT, class _OutputIterator = ostreambuf_iterator<_CharT> >
+class _LIBCPP_TYPE_VIS_ONLY num_put
+    : public locale::facet,
+      private __num_put<_CharT>
+{
+public:
+    typedef _CharT char_type;
+    typedef _OutputIterator iter_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit num_put(size_t __refs = 0)
+        : locale::facet(__refs) {}
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
+                  bool __v) const
+    {
+        return do_put(__s, __iob, __fl, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
+                  long __v) const
+    {
+        return do_put(__s, __iob, __fl, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
+                  long long __v) const
+    {
+        return do_put(__s, __iob, __fl, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
+                  unsigned long __v) const
+    {
+        return do_put(__s, __iob, __fl, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
+                  unsigned long long __v) const
+    {
+        return do_put(__s, __iob, __fl, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
+                  double __v) const
+    {
+        return do_put(__s, __iob, __fl, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
+                  long double __v) const
+    {
+        return do_put(__s, __iob, __fl, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
+                  const void* __v) const
+    {
+        return do_put(__s, __iob, __fl, __v);
+    }
+
+    static locale::id id;
+
+protected:
+    _LIBCPP_ALWAYS_INLINE
+    ~num_put() {}
+
+    virtual iter_type do_put(iter_type __s, ios_base& __iob, char_type __fl,
+                             bool __v) const;
+    virtual iter_type do_put(iter_type __s, ios_base& __iob, char_type __fl,
+                             long __v) const;
+    virtual iter_type do_put(iter_type __s, ios_base& __iob, char_type __fl,
+                             long long __v) const;
+    virtual iter_type do_put(iter_type __s, ios_base& __iob, char_type __fl,
+                             unsigned long) const;
+    virtual iter_type do_put(iter_type __s, ios_base& __iob, char_type __fl,
+                             unsigned long long) const;
+    virtual iter_type do_put(iter_type __s, ios_base& __iob, char_type __fl,
+                             double __v) const;
+    virtual iter_type do_put(iter_type __s, ios_base& __iob, char_type __fl,
+                             long double __v) const;
+    virtual iter_type do_put(iter_type __s, ios_base& __iob, char_type __fl,
+                             const void* __v) const;
+};
+
+template <class _CharT, class _OutputIterator>
+locale::id
+num_put<_CharT, _OutputIterator>::id;
+
+template <class _CharT, class _OutputIterator>
+_LIBCPP_HIDDEN
+_OutputIterator
+__pad_and_output(_OutputIterator __s,
+                 const _CharT* __ob, const _CharT* __op, const _CharT* __oe,
+                 ios_base& __iob, _CharT __fl)
+{
+    streamsize __sz = __oe - __ob;
+    streamsize __ns = __iob.width();
+    if (__ns > __sz)
+        __ns -= __sz;
+    else
+        __ns = 0;
+    for (;__ob < __op; ++__ob, ++__s)
+        *__s = *__ob;
+    for (; __ns; --__ns, ++__s)
+        *__s = __fl;
+    for (; __ob < __oe; ++__ob, ++__s)
+        *__s = *__ob;
+    __iob.width(0);
+    return __s;
+}
+
+#if !defined(__APPLE__) || \
+    (defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && __MAC_OS_X_VERSION_MIN_REQUIRED > __MAC_10_8) || \
+    (defined(__IPHONE_OS_VERSION_MIN_REQUIRED) && __IPHONE_OS_VERSION_MIN_REQUIRED > __IPHONE_6_0)
+
+template <class _CharT, class _Traits>
+_LIBCPP_HIDDEN
+ostreambuf_iterator<_CharT, _Traits>
+__pad_and_output(ostreambuf_iterator<_CharT, _Traits> __s,
+                 const _CharT* __ob, const _CharT* __op, const _CharT* __oe,
+                 ios_base& __iob, _CharT __fl)
+{
+    if (__s.__sbuf_ == nullptr)
+        return __s;
+    streamsize __sz = __oe - __ob;
+    streamsize __ns = __iob.width();
+    if (__ns > __sz)
+        __ns -= __sz;
+    else
+        __ns = 0;
+    streamsize __np = __op - __ob;
+    if (__np > 0)
+    {
+        if (__s.__sbuf_->sputn(__ob, __np) != __np)
+        {
+            __s.__sbuf_ = nullptr;
+            return __s;
+        }
+    }
+    if (__ns > 0)
+    {
+        basic_string<_CharT, _Traits> __sp(__ns, __fl);
+        if (__s.__sbuf_->sputn(__sp.data(), __ns) != __ns)
+        {
+            __s.__sbuf_ = nullptr;
+            return __s;
+        }
+    }
+    __np = __oe - __op;
+    if (__np > 0)
+    {
+        if (__s.__sbuf_->sputn(__op, __np) != __np)
+        {
+            __s.__sbuf_ = nullptr;
+            return __s;
+        }
+    }
+    __iob.width(0);
+    return __s;
+}
+
+#endif
+
+template <class _CharT, class _OutputIterator>
+_OutputIterator
+num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
+                                         char_type __fl, bool __v) const
+{
+    if ((__iob.flags() & ios_base::boolalpha) == 0)
+        return do_put(__s, __iob, __fl, (unsigned long)__v);
+    const numpunct<char_type>& __np = use_facet<numpunct<char_type> >(__iob.getloc());
+    typedef typename numpunct<char_type>::string_type string_type;
+#if _LIBCPP_DEBUG_LEVEL >= 2
+    string_type __tmp(__v ? __np.truename() : __np.falsename());
+    string_type __nm = _VSTD::move(__tmp);
+#else
+    string_type __nm = __v ? __np.truename() : __np.falsename();
+#endif
+    for (typename string_type::iterator __i = __nm.begin(); __i != __nm.end(); ++__i, ++__s)
+        *__s = *__i;
+    return __s;
+}
+
+template <class _CharT, class _OutputIterator>
+_OutputIterator
+num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
+                                         char_type __fl, long __v) const
+{
+    // Stage 1 - Get number in narrow char
+    char __fmt[6] = {'%', 0};
+    const char* __len = "l";
+    this->__format_int(__fmt+1, __len, true, __iob.flags());
+    const unsigned __nbuf = (numeric_limits<long>::digits / 3)
+                          + ((numeric_limits<long>::digits % 3) != 0)
+                          + 1;
+    char __nar[__nbuf];
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+    int __nc = snprintf_l(__nar, sizeof(__nar), _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#else
+    int __nc = __snprintf_l(__nar, sizeof(__nar), _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#endif
+    char* __ne = __nar + __nc;
+    char* __np = this->__identify_padding(__nar, __ne, __iob);
+    // Stage 2 - Widen __nar while adding thousands separators
+    char_type __o[2*(__nbuf-1) - 1];
+    char_type* __op;  // pad here
+    char_type* __oe;  // end of output
+    this->__widen_and_group_int(__nar, __np, __ne, __o, __op, __oe, __iob.getloc());
+    // [__o, __oe) contains thousands_sep'd wide number
+    // Stage 3 & 4
+    return __pad_and_output(__s, __o, __op, __oe, __iob, __fl);
+}
+
+template <class _CharT, class _OutputIterator>
+_OutputIterator
+num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
+                                         char_type __fl, long long __v) const
+{
+    // Stage 1 - Get number in narrow char
+    char __fmt[8] = {'%', 0};
+    const char* __len = "ll";
+    this->__format_int(__fmt+1, __len, true, __iob.flags());
+    const unsigned __nbuf = (numeric_limits<long long>::digits / 3)
+                          + ((numeric_limits<long long>::digits % 3) != 0)
+                          + 2;
+    char __nar[__nbuf];
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+    int __nc = snprintf_l(__nar, sizeof(__nar), _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#else
+    int __nc = __snprintf_l(__nar, sizeof(__nar), _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#endif
+    char* __ne = __nar + __nc;
+    char* __np = this->__identify_padding(__nar, __ne, __iob);
+    // Stage 2 - Widen __nar while adding thousands separators
+    char_type __o[2*(__nbuf-1) - 1];
+    char_type* __op;  // pad here
+    char_type* __oe;  // end of output
+    this->__widen_and_group_int(__nar, __np, __ne, __o, __op, __oe, __iob.getloc());
+    // [__o, __oe) contains thousands_sep'd wide number
+    // Stage 3 & 4
+    return __pad_and_output(__s, __o, __op, __oe, __iob, __fl);
+}
+
+template <class _CharT, class _OutputIterator>
+_OutputIterator
+num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
+                                         char_type __fl, unsigned long __v) const
+{
+    // Stage 1 - Get number in narrow char
+    char __fmt[6] = {'%', 0};
+    const char* __len = "l";
+    this->__format_int(__fmt+1, __len, false, __iob.flags());
+    const unsigned __nbuf = (numeric_limits<unsigned long>::digits / 3)
+                          + ((numeric_limits<unsigned long>::digits % 3) != 0)
+                          + 1;
+    char __nar[__nbuf];
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+    int __nc = snprintf_l(__nar, sizeof(__nar), _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#else
+    int __nc = __snprintf_l(__nar, sizeof(__nar), _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#endif
+    char* __ne = __nar + __nc;
+    char* __np = this->__identify_padding(__nar, __ne, __iob);
+    // Stage 2 - Widen __nar while adding thousands separators
+    char_type __o[2*(__nbuf-1) - 1];
+    char_type* __op;  // pad here
+    char_type* __oe;  // end of output
+    this->__widen_and_group_int(__nar, __np, __ne, __o, __op, __oe, __iob.getloc());
+    // [__o, __oe) contains thousands_sep'd wide number
+    // Stage 3 & 4
+    return __pad_and_output(__s, __o, __op, __oe, __iob, __fl);
+}
+
+template <class _CharT, class _OutputIterator>
+_OutputIterator
+num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
+                                         char_type __fl, unsigned long long __v) const
+{
+    // Stage 1 - Get number in narrow char
+    char __fmt[8] = {'%', 0};
+    const char* __len = "ll";
+    this->__format_int(__fmt+1, __len, false, __iob.flags());
+    const unsigned __nbuf = (numeric_limits<unsigned long long>::digits / 3)
+                          + ((numeric_limits<unsigned long long>::digits % 3) != 0)
+                          + 1;
+    char __nar[__nbuf];
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+    int __nc = snprintf_l(__nar, sizeof(__nar), _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#else
+    int __nc = __snprintf_l(__nar, sizeof(__nar), _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#endif
+    char* __ne = __nar + __nc;
+    char* __np = this->__identify_padding(__nar, __ne, __iob);
+    // Stage 2 - Widen __nar while adding thousands separators
+    char_type __o[2*(__nbuf-1) - 1];
+    char_type* __op;  // pad here
+    char_type* __oe;  // end of output
+    this->__widen_and_group_int(__nar, __np, __ne, __o, __op, __oe, __iob.getloc());
+    // [__o, __oe) contains thousands_sep'd wide number
+    // Stage 3 & 4
+    return __pad_and_output(__s, __o, __op, __oe, __iob, __fl);
+}
+
+template <class _CharT, class _OutputIterator>
+_OutputIterator
+num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
+                                         char_type __fl, double __v) const
+{
+    // Stage 1 - Get number in narrow char
+    char __fmt[8] = {'%', 0};
+    const char* __len = "";
+    bool __specify_precision = this->__format_float(__fmt+1, __len, __iob.flags());
+    const unsigned __nbuf = 30;
+    char __nar[__nbuf];
+    char* __nb = __nar;
+    int __nc;
+    if (__specify_precision)
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+        __nc = snprintf_l(__nb, __nbuf, _LIBCPP_GET_C_LOCALE, __fmt,
+                                   (int)__iob.precision(), __v);
+#else
+        __nc = __snprintf_l(__nb, __nbuf, _LIBCPP_GET_C_LOCALE, __fmt,
+                                   (int)__iob.precision(), __v);
+#endif
+    else
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+        __nc = snprintf_l(__nb, __nbuf, _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#else
+        __nc = __snprintf_l(__nb, __nbuf, _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#endif
+    unique_ptr<char, void(*)(void*)> __nbh(0, free);
+    if (__nc > static_cast<int>(__nbuf-1))
+    {
+        if (__specify_precision)
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+            __nc = asprintf_l(&__nb, _LIBCPP_GET_C_LOCALE, __fmt, (int)__iob.precision(), __v);
+#else
+            __nc = __asprintf_l(&__nb, _LIBCPP_GET_C_LOCALE, __fmt, (int)__iob.precision(), __v);
+#endif
+        else
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+            __nc = asprintf_l(&__nb, _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#else
+            __nc = __asprintf_l(&__nb, _LIBCPP_GET_C_LOCALE, __fmt, (int)__iob.precision(), __v);
+#endif
+        if (__nb == 0)
+            __throw_bad_alloc();
+        __nbh.reset(__nb);
+    }
+    char* __ne = __nb + __nc;
+    char* __np = this->__identify_padding(__nb, __ne, __iob);
+    // Stage 2 - Widen __nar while adding thousands separators
+    char_type __o[2*(__nbuf-1) - 1];
+    char_type* __ob = __o;
+    unique_ptr<char_type, void(*)(void*)> __obh(0, free);
+    if (__nb != __nar)
+    {
+        __ob = (char_type*)malloc(2*static_cast<size_t>(__nc)*sizeof(char_type));
+        if (__ob == 0)
+            __throw_bad_alloc();
+        __obh.reset(__ob);
+    }
+    char_type* __op;  // pad here
+    char_type* __oe;  // end of output
+    this->__widen_and_group_float(__nb, __np, __ne, __ob, __op, __oe, __iob.getloc());
+    // [__o, __oe) contains thousands_sep'd wide number
+    // Stage 3 & 4
+    __s = __pad_and_output(__s, __ob, __op, __oe, __iob, __fl);
+    return __s;
+}
+
+template <class _CharT, class _OutputIterator>
+_OutputIterator
+num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
+                                         char_type __fl, long double __v) const
+{
+    // Stage 1 - Get number in narrow char
+    char __fmt[8] = {'%', 0};
+    const char* __len = "L";
+    bool __specify_precision = this->__format_float(__fmt+1, __len, __iob.flags());
+    const unsigned __nbuf = 30;
+    char __nar[__nbuf];
+    char* __nb = __nar;
+    int __nc;
+    if (__specify_precision)
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+        __nc = snprintf_l(__nb, __nbuf, _LIBCPP_GET_C_LOCALE, __fmt,
+                                   (int)__iob.precision(), __v);
+#else
+        __nc = __snprintf_l(__nb, __nbuf, _LIBCPP_GET_C_LOCALE, __fmt,
+                                   (int)__iob.precision(), __v);
+#endif
+    else
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+        __nc = snprintf_l(__nb, __nbuf, _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#else
+        __nc = __snprintf_l(__nb, __nbuf, _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#endif
+    unique_ptr<char, void(*)(void*)> __nbh(0, free);
+    if (__nc > static_cast<int>(__nbuf-1))
+    {
+        if (__specify_precision)
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+            __nc = asprintf_l(&__nb, _LIBCPP_GET_C_LOCALE, __fmt, (int)__iob.precision(), __v);
+#else
+            __nc = __asprintf_l(&__nb, _LIBCPP_GET_C_LOCALE, __fmt, (int)__iob.precision(), __v);
+#endif
+        else
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+            __nc = asprintf_l(&__nb, _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#else
+            __nc = __asprintf_l(&__nb, _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#endif
+        if (__nb == 0)
+            __throw_bad_alloc();
+        __nbh.reset(__nb);
+    }
+    char* __ne = __nb + __nc;
+    char* __np = this->__identify_padding(__nb, __ne, __iob);
+    // Stage 2 - Widen __nar while adding thousands separators
+    char_type __o[2*(__nbuf-1) - 1];
+    char_type* __ob = __o;
+    unique_ptr<char_type, void(*)(void*)> __obh(0, free);
+    if (__nb != __nar)
+    {
+        __ob = (char_type*)malloc(2*static_cast<size_t>(__nc)*sizeof(char_type));
+        if (__ob == 0)
+            __throw_bad_alloc();
+        __obh.reset(__ob);
+    }
+    char_type* __op;  // pad here
+    char_type* __oe;  // end of output
+    this->__widen_and_group_float(__nb, __np, __ne, __ob, __op, __oe, __iob.getloc());
+    // [__o, __oe) contains thousands_sep'd wide number
+    // Stage 3 & 4
+    __s = __pad_and_output(__s, __ob, __op, __oe, __iob, __fl);
+    return __s;
+}
+
+template <class _CharT, class _OutputIterator>
+_OutputIterator
+num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
+                                         char_type __fl, const void* __v) const
+{
+    // Stage 1 - Get pointer in narrow char
+    char __fmt[6] = "%p";
+    const unsigned __nbuf = 20;
+    char __nar[__nbuf];
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+    int __nc = snprintf_l(__nar, sizeof(__nar), _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#else
+    int __nc = __snprintf_l(__nar, sizeof(__nar), _LIBCPP_GET_C_LOCALE, __fmt, __v);
+#endif
+    char* __ne = __nar + __nc;
+    char* __np = this->__identify_padding(__nar, __ne, __iob);
+    // Stage 2 - Widen __nar
+    char_type __o[2*(__nbuf-1) - 1];
+    char_type* __op;  // pad here
+    char_type* __oe;  // end of output
+    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__iob.getloc());
+    __ct.widen(__nar, __ne, __o);
+    __oe = __o + (__ne - __nar);
+    if (__np == __ne)
+        __op = __oe;
+    else
+        __op = __o + (__np - __nar);
+    // [__o, __oe) contains wide number
+    // Stage 3 & 4
+    return __pad_and_output(__s, __o, __op, __oe, __iob, __fl);
+}
+
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS num_put<char>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS num_put<wchar_t>)
+
+template <class _CharT, class _InputIterator>
+_LIBCPP_HIDDEN
+int
+__get_up_to_n_digits(_InputIterator& __b, _InputIterator __e,
+                     ios_base::iostate& __err, const ctype<_CharT>& __ct, int __n)
+{
+    // Precondition:  __n >= 1
+    if (__b == __e)
+    {
+        __err |= ios_base::eofbit | ios_base::failbit;
+        return 0;
+    }
+    // get first digit
+    _CharT __c = *__b;
+    if (!__ct.is(ctype_base::digit, __c))
+    {
+        __err |= ios_base::failbit;
+        return 0;
+    }
+    int __r = __ct.narrow(__c, 0) - '0';
+    for (++__b, (void) --__n; __b != __e && __n > 0; ++__b, (void) --__n)
+    {
+        // get next digit
+        __c = *__b;
+        if (!__ct.is(ctype_base::digit, __c))
+            return __r;
+        __r = __r * 10 + __ct.narrow(__c, 0) - '0';
+    }
+    if (__b == __e)
+        __err |= ios_base::eofbit;
+    return __r;
+}
+
+class _LIBCPP_TYPE_VIS time_base
+{
+public:
+    enum dateorder {no_order, dmy, mdy, ymd, ydm};
+};
+
+template <class _CharT>
+class _LIBCPP_TYPE_VIS_ONLY __time_get_c_storage
+{
+protected:
+    typedef basic_string<_CharT> string_type;
+
+    virtual const string_type* __weeks() const;
+    virtual const string_type* __months() const;
+    virtual const string_type* __am_pm() const;
+    virtual const string_type& __c() const;
+    virtual const string_type& __r() const;
+    virtual const string_type& __x() const;
+    virtual const string_type& __X() const;
+};
+
+template <class _CharT, class _InputIterator = istreambuf_iterator<_CharT> >
+class _LIBCPP_TYPE_VIS_ONLY time_get
+    : public locale::facet,
+      public time_base,
+      private __time_get_c_storage<_CharT>
+{
+public:
+    typedef _CharT                  char_type;
+    typedef _InputIterator          iter_type;
+    typedef time_base::dateorder    dateorder;
+    typedef basic_string<char_type> string_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit time_get(size_t __refs = 0)
+        : locale::facet(__refs) {}
+
+    _LIBCPP_ALWAYS_INLINE
+    dateorder date_order() const
+    {
+        return this->do_date_order();
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get_time(iter_type __b, iter_type __e, ios_base& __iob,
+                       ios_base::iostate& __err, tm* __tm) const
+    {
+        return do_get_time(__b, __e, __iob, __err, __tm);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get_date(iter_type __b, iter_type __e, ios_base& __iob,
+                       ios_base::iostate& __err, tm* __tm) const
+    {
+        return do_get_date(__b, __e, __iob, __err, __tm);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get_weekday(iter_type __b, iter_type __e, ios_base& __iob,
+                          ios_base::iostate& __err, tm* __tm) const
+    {
+        return do_get_weekday(__b, __e, __iob, __err, __tm);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get_monthname(iter_type __b, iter_type __e, ios_base& __iob,
+                            ios_base::iostate& __err, tm* __tm) const
+    {
+        return do_get_monthname(__b, __e, __iob, __err, __tm);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get_year(iter_type __b, iter_type __e, ios_base& __iob,
+                       ios_base::iostate& __err, tm* __tm) const
+    {
+        return do_get_year(__b, __e, __iob, __err, __tm);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
+                  ios_base::iostate& __err, tm *__tm,
+                  char __fmt, char __mod = 0) const
+    {
+        return do_get(__b, __e, __iob, __err, __tm, __fmt, __mod);
+    }
+
+    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
+                  ios_base::iostate& __err, tm* __tm,
+                  const char_type* __fmtb, const char_type* __fmte) const;
+
+    static locale::id id;
+
+protected:
+    _LIBCPP_ALWAYS_INLINE
+    ~time_get() {}
+
+    virtual dateorder do_date_order() const;
+    virtual iter_type do_get_time(iter_type __b, iter_type __e, ios_base& __iob,
+                                  ios_base::iostate& __err, tm* __tm) const;
+    virtual iter_type do_get_date(iter_type __b, iter_type __e, ios_base& __iob,
+                                  ios_base::iostate& __err, tm* __tm) const;
+    virtual iter_type do_get_weekday(iter_type __b, iter_type __e, ios_base& __iob,
+                                     ios_base::iostate& __err, tm* __tm) const;
+    virtual iter_type do_get_monthname(iter_type __b, iter_type __e, ios_base& __iob,
+                                       ios_base::iostate& __err, tm* __tm) const;
+    virtual iter_type do_get_year(iter_type __b, iter_type __e, ios_base& __iob,
+                                  ios_base::iostate& __err, tm* __tm) const;
+    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
+                             ios_base::iostate& __err, tm* __tm,
+                             char __fmt, char __mod) const;
+private:
+    void __get_white_space(iter_type& __b, iter_type __e,
+                           ios_base::iostate& __err, const ctype<char_type>& __ct) const;
+    void __get_percent(iter_type& __b, iter_type __e, ios_base::iostate& __err,
+                       const ctype<char_type>& __ct) const;
+
+    void __get_weekdayname(int& __m,
+                           iter_type& __b, iter_type __e,
+                           ios_base::iostate& __err,
+                           const ctype<char_type>& __ct) const;
+    void __get_monthname(int& __m,
+                         iter_type& __b, iter_type __e,
+                         ios_base::iostate& __err,
+                         const ctype<char_type>& __ct) const;
+    void __get_day(int& __d,
+                   iter_type& __b, iter_type __e,
+                   ios_base::iostate& __err,
+                   const ctype<char_type>& __ct) const;
+    void __get_month(int& __m,
+                     iter_type& __b, iter_type __e,
+                     ios_base::iostate& __err,
+                     const ctype<char_type>& __ct) const;
+    void __get_year(int& __y,
+                   iter_type& __b, iter_type __e,
+                   ios_base::iostate& __err,
+                   const ctype<char_type>& __ct) const;
+    void __get_year4(int& __y,
+                    iter_type& __b, iter_type __e,
+                    ios_base::iostate& __err,
+                    const ctype<char_type>& __ct) const;
+    void __get_hour(int& __d,
+                    iter_type& __b, iter_type __e,
+                    ios_base::iostate& __err,
+                    const ctype<char_type>& __ct) const;
+    void __get_12_hour(int& __h,
+                       iter_type& __b, iter_type __e,
+                       ios_base::iostate& __err,
+                       const ctype<char_type>& __ct) const;
+    void __get_am_pm(int& __h,
+                     iter_type& __b, iter_type __e,
+                     ios_base::iostate& __err,
+                     const ctype<char_type>& __ct) const;
+    void __get_minute(int& __m,
+                      iter_type& __b, iter_type __e,
+                      ios_base::iostate& __err,
+                      const ctype<char_type>& __ct) const;
+    void __get_second(int& __s,
+                      iter_type& __b, iter_type __e,
+                      ios_base::iostate& __err,
+                      const ctype<char_type>& __ct) const;
+    void __get_weekday(int& __w,
+                       iter_type& __b, iter_type __e,
+                       ios_base::iostate& __err,
+                       const ctype<char_type>& __ct) const;
+    void __get_day_year_num(int& __w,
+                            iter_type& __b, iter_type __e,
+                            ios_base::iostate& __err,
+                            const ctype<char_type>& __ct) const;
+};
+
+template <class _CharT, class _InputIterator>
+locale::id
+time_get<_CharT, _InputIterator>::id;
+
+// time_get primitives
+
+template <class _CharT, class _InputIterator>
+void
+time_get<_CharT, _InputIterator>::__get_weekdayname(int& __w,
+                                                    iter_type& __b, iter_type __e,
+                                                    ios_base::iostate& __err,
+                                                    const ctype<char_type>& __ct) const
+{
+    // Note:  ignoring case comes from the POSIX strptime spec
+    const string_type* __wk = this->__weeks();
+    ptrdiff_t __i = __scan_keyword(__b, __e, __wk, __wk+14, __ct, __err, false) - __wk;
+    if (__i < 14)
+        __w = __i % 7;
+}
+
+template <class _CharT, class _InputIterator>
+void
+time_get<_CharT, _InputIterator>::__get_monthname(int& __m,
+                                                  iter_type& __b, iter_type __e,
+                                                  ios_base::iostate& __err,
+                                                  const ctype<char_type>& __ct) const
+{
+    // Note:  ignoring case comes from the POSIX strptime spec
+    const string_type* __month = this->__months();
+    ptrdiff_t __i = __scan_keyword(__b, __e, __month, __month+24, __ct, __err, false) - __month;
+    if (__i < 24)
+        __m = __i % 12;
+}
+
+template <class _CharT, class _InputIterator>
+void
+time_get<_CharT, _InputIterator>::__get_day(int& __d,
+                                            iter_type& __b, iter_type __e,
+                                            ios_base::iostate& __err,
+                                            const ctype<char_type>& __ct) const
+{
+    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 2);
+    if (!(__err & ios_base::failbit) && 1 <= __t && __t <= 31)
+        __d = __t;
+    else
+        __err |= ios_base::failbit;
+}
+
+template <class _CharT, class _InputIterator>
+void
+time_get<_CharT, _InputIterator>::__get_month(int& __m,
+                                              iter_type& __b, iter_type __e,
+                                              ios_base::iostate& __err,
+                                              const ctype<char_type>& __ct) const
+{
+    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 2) - 1;
+    if (!(__err & ios_base::failbit) && __t <= 11)
+        __m = __t;
+    else
+        __err |= ios_base::failbit;
+}
+
+template <class _CharT, class _InputIterator>
+void
+time_get<_CharT, _InputIterator>::__get_year(int& __y,
+                                             iter_type& __b, iter_type __e,
+                                             ios_base::iostate& __err,
+                                             const ctype<char_type>& __ct) const
+{
+    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 4);
+    if (!(__err & ios_base::failbit))
+    {
+        if (__t < 69)
+            __t += 2000;
+        else if (69 <= __t && __t <= 99)
+            __t += 1900;
+        __y = __t - 1900;
+    }
+}
+
+template <class _CharT, class _InputIterator>
+void
+time_get<_CharT, _InputIterator>::__get_year4(int& __y,
+                                              iter_type& __b, iter_type __e,
+                                              ios_base::iostate& __err,
+                                              const ctype<char_type>& __ct) const
+{
+    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 4);
+    if (!(__err & ios_base::failbit))
+        __y = __t - 1900;
+}
+
+template <class _CharT, class _InputIterator>
+void
+time_get<_CharT, _InputIterator>::__get_hour(int& __h,
+                                             iter_type& __b, iter_type __e,
+                                             ios_base::iostate& __err,
+                                             const ctype<char_type>& __ct) const
+{
+    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 2);
+    if (!(__err & ios_base::failbit) && __t <= 23)
+        __h = __t;
+    else
+        __err |= ios_base::failbit;
+}
+
+template <class _CharT, class _InputIterator>
+void
+time_get<_CharT, _InputIterator>::__get_12_hour(int& __h,
+                                                iter_type& __b, iter_type __e,
+                                                ios_base::iostate& __err,
+                                                const ctype<char_type>& __ct) const
+{
+    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 2);
+    if (!(__err & ios_base::failbit) && 1 <= __t && __t <= 12)
+        __h = __t;
+    else
+        __err |= ios_base::failbit;
+}
+
+template <class _CharT, class _InputIterator>
+void
+time_get<_CharT, _InputIterator>::__get_minute(int& __m,
+                                               iter_type& __b, iter_type __e,
+                                               ios_base::iostate& __err,
+                                               const ctype<char_type>& __ct) const
+{
+    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 2);
+    if (!(__err & ios_base::failbit) && __t <= 59)
+        __m = __t;
+    else
+        __err |= ios_base::failbit;
+}
+
+template <class _CharT, class _InputIterator>
+void
+time_get<_CharT, _InputIterator>::__get_second(int& __s,
+                                               iter_type& __b, iter_type __e,
+                                               ios_base::iostate& __err,
+                                               const ctype<char_type>& __ct) const
+{
+    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 2);
+    if (!(__err & ios_base::failbit) && __t <= 60)
+        __s = __t;
+    else
+        __err |= ios_base::failbit;
+}
+
+template <class _CharT, class _InputIterator>
+void
+time_get<_CharT, _InputIterator>::__get_weekday(int& __w,
+                                                iter_type& __b, iter_type __e,
+                                                ios_base::iostate& __err,
+                                                const ctype<char_type>& __ct) const
+{
+    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 1);
+    if (!(__err & ios_base::failbit) && __t <= 6)
+        __w = __t;
+    else
+        __err |= ios_base::failbit;
+}
+
+template <class _CharT, class _InputIterator>
+void
+time_get<_CharT, _InputIterator>::__get_day_year_num(int& __d,
+                                                     iter_type& __b, iter_type __e,
+                                                     ios_base::iostate& __err,
+                                                     const ctype<char_type>& __ct) const
+{
+    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 3);
+    if (!(__err & ios_base::failbit) && __t <= 365)
+        __d = __t;
+    else
+        __err |= ios_base::failbit;
+}
+
+template <class _CharT, class _InputIterator>
+void
+time_get<_CharT, _InputIterator>::__get_white_space(iter_type& __b, iter_type __e,
+                                                    ios_base::iostate& __err,
+                                                    const ctype<char_type>& __ct) const
+{
+    for (; __b != __e && __ct.is(ctype_base::space, *__b); ++__b)
+        ;
+    if (__b == __e)
+        __err |= ios_base::eofbit;
+}
+
+template <class _CharT, class _InputIterator>
+void
+time_get<_CharT, _InputIterator>::__get_am_pm(int& __h,
+                                              iter_type& __b, iter_type __e,
+                                              ios_base::iostate& __err,
+                                              const ctype<char_type>& __ct) const
+{
+    const string_type* __ap = this->__am_pm();
+    if (__ap[0].size() + __ap[1].size() == 0)
+    {
+        __err |= ios_base::failbit;
+        return;
+    }
+    ptrdiff_t __i = __scan_keyword(__b, __e, __ap, __ap+2, __ct, __err, false) - __ap;
+    if (__i == 0 && __h == 12)
+        __h = 0;
+    else if (__i == 1 && __h < 12)
+        __h += 12;
+}
+
+template <class _CharT, class _InputIterator>
+void
+time_get<_CharT, _InputIterator>::__get_percent(iter_type& __b, iter_type __e,
+                                                ios_base::iostate& __err,
+                                                const ctype<char_type>& __ct) const
+{
+    if (__b == __e)
+    {
+        __err |= ios_base::eofbit | ios_base::failbit;
+        return;
+    }
+    if (__ct.narrow(*__b, 0) != '%')
+        __err |= ios_base::failbit;
+    else if(++__b == __e)
+        __err |= ios_base::eofbit;
+}
+
+// time_get end primitives
+
+template <class _CharT, class _InputIterator>
+_InputIterator
+time_get<_CharT, _InputIterator>::get(iter_type __b, iter_type __e,
+                                      ios_base& __iob,
+                                      ios_base::iostate& __err, tm* __tm,
+                                      const char_type* __fmtb, const char_type* __fmte) const
+{
+    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__iob.getloc());
+    __err = ios_base::goodbit;
+    while (__fmtb != __fmte && __err == ios_base::goodbit)
+    {
+        if (__b == __e)
+        {
+            __err = ios_base::failbit;
+            break;
+        }
+        if (__ct.narrow(*__fmtb, 0) == '%')
+        {
+            if (++__fmtb == __fmte)
+            {
+                __err = ios_base::failbit;
+                break;
+            }
+            char __cmd = __ct.narrow(*__fmtb, 0);
+            char __opt = '\0';
+            if (__cmd == 'E' || __cmd == '0')
+            {
+                if (++__fmtb == __fmte)
+                {
+                    __err = ios_base::failbit;
+                    break;
+                }
+                __opt = __cmd;
+                __cmd = __ct.narrow(*__fmtb, 0);
+            }
+            __b = do_get(__b, __e, __iob, __err, __tm, __cmd, __opt);
+            ++__fmtb;
+        }
+        else if (__ct.is(ctype_base::space, *__fmtb))
+        {
+            for (++__fmtb; __fmtb != __fmte && __ct.is(ctype_base::space, *__fmtb); ++__fmtb)
+                ;
+            for (        ;    __b != __e    && __ct.is(ctype_base::space, *__b);    ++__b)
+                ;
+        }
+        else if (__ct.toupper(*__b) == __ct.toupper(*__fmtb))
+        {
+            ++__b;
+            ++__fmtb;
+        }
+        else
+            __err = ios_base::failbit;
+    }
+    if (__b == __e)
+        __err |= ios_base::eofbit;
+    return __b;
+}
+
+template <class _CharT, class _InputIterator>
+typename time_get<_CharT, _InputIterator>::dateorder
+time_get<_CharT, _InputIterator>::do_date_order() const
+{
+    return mdy;
+}
+
+template <class _CharT, class _InputIterator>
+_InputIterator
+time_get<_CharT, _InputIterator>::do_get_time(iter_type __b, iter_type __e,
+                                              ios_base& __iob,
+                                              ios_base::iostate& __err,
+                                              tm* __tm) const
+{
+    const char_type __fmt[] = {'%', 'H', ':', '%', 'M', ':', '%', 'S'};
+    return get(__b, __e, __iob, __err, __tm, __fmt, __fmt + sizeof(__fmt)/sizeof(__fmt[0]));
+}
+
+template <class _CharT, class _InputIterator>
+_InputIterator
+time_get<_CharT, _InputIterator>::do_get_date(iter_type __b, iter_type __e,
+                                              ios_base& __iob,
+                                              ios_base::iostate& __err,
+                                              tm* __tm) const
+{
+    const string_type& __fmt = this->__x();
+    return get(__b, __e, __iob, __err, __tm, __fmt.data(), __fmt.data() + __fmt.size());
+}
+
+template <class _CharT, class _InputIterator>
+_InputIterator
+time_get<_CharT, _InputIterator>::do_get_weekday(iter_type __b, iter_type __e,
+                                                 ios_base& __iob,
+                                                 ios_base::iostate& __err,
+                                                 tm* __tm) const
+{
+    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__iob.getloc());
+    __get_weekdayname(__tm->tm_wday, __b, __e, __err, __ct);
+    return __b;
+}
+
+template <class _CharT, class _InputIterator>
+_InputIterator
+time_get<_CharT, _InputIterator>::do_get_monthname(iter_type __b, iter_type __e,
+                                                   ios_base& __iob,
+                                                   ios_base::iostate& __err,
+                                                   tm* __tm) const
+{
+    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__iob.getloc());
+    __get_monthname(__tm->tm_mon, __b, __e, __err, __ct);
+    return __b;
+}
+
+template <class _CharT, class _InputIterator>
+_InputIterator
+time_get<_CharT, _InputIterator>::do_get_year(iter_type __b, iter_type __e,
+                                              ios_base& __iob,
+                                              ios_base::iostate& __err,
+                                              tm* __tm) const
+{
+    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__iob.getloc());
+    __get_year(__tm->tm_year, __b, __e, __err, __ct);
+    return __b;
+}
+
+template <class _CharT, class _InputIterator>
+_InputIterator
+time_get<_CharT, _InputIterator>::do_get(iter_type __b, iter_type __e,
+                                         ios_base& __iob,
+                                         ios_base::iostate& __err, tm* __tm,
+                                         char __fmt, char) const
+{
+    __err = ios_base::goodbit;
+    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__iob.getloc());
+    switch (__fmt)
+    {
+    case 'a':
+    case 'A':
+        __get_weekdayname(__tm->tm_wday, __b, __e, __err, __ct);
+        break;
+    case 'b':
+    case 'B':
+    case 'h':
+        __get_monthname(__tm->tm_mon, __b, __e, __err, __ct);
+        break;
+    case 'c':
+        {
+        const string_type& __fm = this->__c();
+        __b = get(__b, __e, __iob, __err, __tm, __fm.data(), __fm.data() + __fm.size());
+        }
+        break;
+    case 'd':
+    case 'e':
+        __get_day(__tm->tm_mday, __b, __e, __err, __ct);
+        break;
+    case 'D':
+        {
+        const char_type __fm[] = {'%', 'm', '/', '%', 'd', '/', '%', 'y'};
+        __b = get(__b, __e, __iob, __err, __tm, __fm, __fm + sizeof(__fm)/sizeof(__fm[0]));
+        }
+        break;
+    case 'F':
+        {
+        const char_type __fm[] = {'%', 'Y', '-', '%', 'm', '-', '%', 'd'};
+        __b = get(__b, __e, __iob, __err, __tm, __fm, __fm + sizeof(__fm)/sizeof(__fm[0]));
+        }
+        break;
+    case 'H':
+        __get_hour(__tm->tm_hour, __b, __e, __err, __ct);
+        break;
+    case 'I':
+        __get_12_hour(__tm->tm_hour, __b, __e, __err, __ct);
+        break;
+    case 'j':
+        __get_day_year_num(__tm->tm_yday, __b, __e, __err, __ct);
+        break;
+    case 'm':
+        __get_month(__tm->tm_mon, __b, __e, __err, __ct);
+        break;
+    case 'M':
+        __get_minute(__tm->tm_min, __b, __e, __err, __ct);
+        break;
+    case 'n':
+    case 't':
+        __get_white_space(__b, __e, __err, __ct);
+        break;
+    case 'p':
+        __get_am_pm(__tm->tm_hour, __b, __e, __err, __ct);
+        break;
+    case 'r':
+        {
+        const char_type __fm[] = {'%', 'I', ':', '%', 'M', ':', '%', 'S', ' ', '%', 'p'};
+        __b = get(__b, __e, __iob, __err, __tm, __fm, __fm + sizeof(__fm)/sizeof(__fm[0]));
+        }
+        break;
+    case 'R':
+        {
+        const char_type __fm[] = {'%', 'H', ':', '%', 'M'};
+        __b = get(__b, __e, __iob, __err, __tm, __fm, __fm + sizeof(__fm)/sizeof(__fm[0]));
+        }
+        break;
+    case 'S':
+        __get_second(__tm->tm_sec, __b, __e, __err, __ct);
+        break;
+    case 'T':
+        {
+        const char_type __fm[] = {'%', 'H', ':', '%', 'M', ':', '%', 'S'};
+        __b = get(__b, __e, __iob, __err, __tm, __fm, __fm + sizeof(__fm)/sizeof(__fm[0]));
+        }
+        break;
+    case 'w':
+        __get_weekday(__tm->tm_wday, __b, __e, __err, __ct);
+        break;
+    case 'x':
+        return do_get_date(__b, __e, __iob, __err, __tm);
+    case 'X':
+        {
+        const string_type& __fm = this->__X();
+        __b = get(__b, __e, __iob, __err, __tm, __fm.data(), __fm.data() + __fm.size());
+        }
+        break;
+    case 'y':
+        __get_year(__tm->tm_year, __b, __e, __err, __ct);
+        break;
+    case 'Y':
+        __get_year4(__tm->tm_year, __b, __e, __err, __ct);
+        break;
+    case '%':
+        __get_percent(__b, __e, __err, __ct);
+        break;
+    default:
+        __err |= ios_base::failbit;
+    }
+    return __b;
+}
+
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS time_get<char>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS time_get<wchar_t>)
+
+class _LIBCPP_TYPE_VIS __time_get
+{
+protected:
+    locale_t __loc_;
+
+    __time_get(const char* __nm);
+    __time_get(const string& __nm);
+    ~__time_get();
+};
+
+template <class _CharT>
+class _LIBCPP_TYPE_VIS_ONLY __time_get_storage
+    : public __time_get
+{
+protected:
+    typedef basic_string<_CharT> string_type;
+
+    string_type __weeks_[14];
+    string_type __months_[24];
+    string_type __am_pm_[2];
+    string_type __c_;
+    string_type __r_;
+    string_type __x_;
+    string_type __X_;
+
+    explicit __time_get_storage(const char* __nm);
+    explicit __time_get_storage(const string& __nm);
+
+    _LIBCPP_ALWAYS_INLINE ~__time_get_storage() {}
+
+    time_base::dateorder __do_date_order() const;
+
+private:
+    void init(const ctype<_CharT>&);
+    string_type __analyze(char __fmt, const ctype<_CharT>&);
+};
+
+template <class _CharT, class _InputIterator = istreambuf_iterator<_CharT> >
+class _LIBCPP_TYPE_VIS_ONLY time_get_byname
+    : public time_get<_CharT, _InputIterator>,
+      private __time_get_storage<_CharT>
+{
+public:
+    typedef time_base::dateorder    dateorder;
+    typedef _InputIterator          iter_type;
+    typedef _CharT                  char_type;
+    typedef basic_string<char_type> string_type;
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit time_get_byname(const char* __nm, size_t __refs = 0)
+        : time_get<_CharT, _InputIterator>(__refs),
+          __time_get_storage<_CharT>(__nm) {}
+    _LIBCPP_INLINE_VISIBILITY
+    explicit time_get_byname(const string& __nm, size_t __refs = 0)
+        : time_get<_CharT, _InputIterator>(__refs),
+          __time_get_storage<_CharT>(__nm) {}
+
+protected:
+    _LIBCPP_INLINE_VISIBILITY
+    ~time_get_byname() {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    virtual dateorder do_date_order() const {return this->__do_date_order();}
+private:
+    _LIBCPP_INLINE_VISIBILITY
+    virtual const string_type* __weeks() const  {return this->__weeks_;}
+    _LIBCPP_INLINE_VISIBILITY
+    virtual const string_type* __months() const {return this->__months_;}
+    _LIBCPP_INLINE_VISIBILITY
+    virtual const string_type* __am_pm() const  {return this->__am_pm_;}
+    _LIBCPP_INLINE_VISIBILITY
+    virtual const string_type& __c() const      {return this->__c_;}
+    _LIBCPP_INLINE_VISIBILITY
+    virtual const string_type& __r() const      {return this->__r_;}
+    _LIBCPP_INLINE_VISIBILITY
+    virtual const string_type& __x() const      {return this->__x_;}
+    _LIBCPP_INLINE_VISIBILITY
+    virtual const string_type& __X() const      {return this->__X_;}
+};
+
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS time_get_byname<char>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS time_get_byname<wchar_t>)
+
+class _LIBCPP_TYPE_VIS __time_put
+{
+    locale_t __loc_;
+protected:
+    _LIBCPP_ALWAYS_INLINE __time_put() : __loc_(_LIBCPP_GET_C_LOCALE) {}
+    __time_put(const char* __nm);
+    __time_put(const string& __nm);
+    ~__time_put();
+    void __do_put(char* __nb, char*& __ne, const tm* __tm,
+                  char __fmt, char __mod) const;
+    void __do_put(wchar_t* __wb, wchar_t*& __we, const tm* __tm,
+                  char __fmt, char __mod) const;
+};
+
+template <class _CharT, class _OutputIterator = ostreambuf_iterator<_CharT> >
+class _LIBCPP_TYPE_VIS_ONLY time_put
+    : public locale::facet,
+      private __time_put
+{
+public:
+    typedef _CharT char_type;
+    typedef _OutputIterator iter_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit time_put(size_t __refs = 0)
+        : locale::facet(__refs) {}
+
+    iter_type put(iter_type __s, ios_base& __iob, char_type __fl, const tm* __tm,
+                  const char_type* __pb, const char_type* __pe) const;
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
+                  const tm* __tm, char __fmt, char __mod = 0) const
+    {
+        return do_put(__s, __iob, __fl, __tm, __fmt, __mod);
+    }
+
+    static locale::id id;
+
+protected:
+    _LIBCPP_ALWAYS_INLINE
+    ~time_put() {}
+    virtual iter_type do_put(iter_type __s, ios_base&, char_type, const tm* __tm,
+                             char __fmt, char __mod) const;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit time_put(const char* __nm, size_t __refs)
+        : locale::facet(__refs),
+          __time_put(__nm) {}
+    _LIBCPP_ALWAYS_INLINE
+    explicit time_put(const string& __nm, size_t __refs)
+        : locale::facet(__refs),
+          __time_put(__nm) {}
+};
+
+template <class _CharT, class _OutputIterator>
+locale::id
+time_put<_CharT, _OutputIterator>::id;
+
+template <class _CharT, class _OutputIterator>
+_OutputIterator
+time_put<_CharT, _OutputIterator>::put(iter_type __s, ios_base& __iob,
+                                       char_type __fl, const tm* __tm,
+                                       const char_type* __pb,
+                                       const char_type* __pe) const
+{
+    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__iob.getloc());
+    for (; __pb != __pe; ++__pb)
+    {
+        if (__ct.narrow(*__pb, 0) == '%')
+        {
+            if (++__pb == __pe)
+            {
+                *__s++ = __pb[-1];
+                break;
+            }
+            char __mod = 0;
+            char __fmt = __ct.narrow(*__pb, 0);
+            if (__fmt == 'E' || __fmt == 'O')
+            {
+                if (++__pb == __pe)
+                {
+                    *__s++ = __pb[-2];
+                    *__s++ = __pb[-1];
+                    break;
+                }
+                __mod = __fmt;
+                __fmt = __ct.narrow(*__pb, 0);
+            }
+            __s = do_put(__s, __iob, __fl, __tm, __fmt, __mod);
+        }
+        else
+            *__s++ = *__pb;
+    }
+    return __s;
+}
+
+template <class _CharT, class _OutputIterator>
+_OutputIterator
+time_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base&,
+                                          char_type, const tm* __tm,
+                                          char __fmt, char __mod) const
+{
+    char_type __nar[100];
+    char_type* __nb = __nar;
+    char_type* __ne = __nb + 100;
+    __do_put(__nb, __ne, __tm, __fmt, __mod);
+    return _VSTD::copy(__nb, __ne, __s);
+}
+
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS time_put<char>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS time_put<wchar_t>)
+
+template <class _CharT, class _OutputIterator = ostreambuf_iterator<_CharT> >
+class _LIBCPP_TYPE_VIS_ONLY time_put_byname
+    : public time_put<_CharT, _OutputIterator>
+{
+public:
+    _LIBCPP_ALWAYS_INLINE
+    explicit time_put_byname(const char* __nm, size_t __refs = 0)
+        : time_put<_CharT, _OutputIterator>(__nm, __refs) {}
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit time_put_byname(const string& __nm, size_t __refs = 0)
+        : time_put<_CharT, _OutputIterator>(__nm, __refs) {}
+
+protected:
+    _LIBCPP_ALWAYS_INLINE
+    ~time_put_byname() {}
+};
+
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS time_put_byname<char>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS time_put_byname<wchar_t>)
+
+// money_base
+
+class _LIBCPP_TYPE_VIS money_base
+{
+public:
+    enum part {none, space, symbol, sign, value};
+    struct pattern {char field[4];};
+
+    _LIBCPP_ALWAYS_INLINE money_base() {}
+};
+
+// moneypunct
+
+template <class _CharT, bool _International = false>
+class _LIBCPP_TYPE_VIS_ONLY moneypunct
+    : public locale::facet,
+      public money_base
+{
+public:
+    typedef _CharT                  char_type;
+    typedef basic_string<char_type> string_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit moneypunct(size_t __refs = 0)
+        : locale::facet(__refs) {}
+
+    _LIBCPP_ALWAYS_INLINE char_type   decimal_point() const {return do_decimal_point();}
+    _LIBCPP_ALWAYS_INLINE char_type   thousands_sep() const {return do_thousands_sep();}
+    _LIBCPP_ALWAYS_INLINE string      grouping()      const {return do_grouping();}
+    _LIBCPP_ALWAYS_INLINE string_type curr_symbol()   const {return do_curr_symbol();}
+    _LIBCPP_ALWAYS_INLINE string_type positive_sign() const {return do_positive_sign();}
+    _LIBCPP_ALWAYS_INLINE string_type negative_sign() const {return do_negative_sign();}
+    _LIBCPP_ALWAYS_INLINE int         frac_digits()   const {return do_frac_digits();}
+    _LIBCPP_ALWAYS_INLINE pattern     pos_format()    const {return do_pos_format();}
+    _LIBCPP_ALWAYS_INLINE pattern     neg_format()    const {return do_neg_format();}
+
+    static locale::id id;
+    static const bool intl = _International;
+
+protected:
+    _LIBCPP_ALWAYS_INLINE
+    ~moneypunct() {}
+
+    virtual char_type   do_decimal_point() const {return numeric_limits<char_type>::max();}
+    virtual char_type   do_thousands_sep() const {return numeric_limits<char_type>::max();}
+    virtual string      do_grouping()      const {return string();}
+    virtual string_type do_curr_symbol()   const {return string_type();}
+    virtual string_type do_positive_sign() const {return string_type();}
+    virtual string_type do_negative_sign() const {return string_type(1, '-');}
+    virtual int         do_frac_digits()   const {return 0;}
+    virtual pattern     do_pos_format()    const
+        {pattern __p = {{symbol, sign, none, value}}; return __p;}
+    virtual pattern     do_neg_format()    const
+        {pattern __p = {{symbol, sign, none, value}}; return __p;}
+};
+
+template <class _CharT, bool _International>
+locale::id
+moneypunct<_CharT, _International>::id;
+
+template <class _CharT, bool _International>
+const bool
+moneypunct<_CharT, _International>::intl;
+
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS moneypunct<char, false>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS moneypunct<char, true>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS moneypunct<wchar_t, false>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS moneypunct<wchar_t, true>)
+
+// moneypunct_byname
+
+template <class _CharT, bool _International = false>
+class _LIBCPP_TYPE_VIS_ONLY moneypunct_byname
+    : public moneypunct<_CharT, _International>
+{
+public:
+    typedef money_base::pattern  pattern;
+    typedef _CharT                  char_type;
+    typedef basic_string<char_type> string_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit moneypunct_byname(const char* __nm, size_t __refs = 0)
+        : moneypunct<_CharT, _International>(__refs) {init(__nm);}
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit moneypunct_byname(const string& __nm, size_t __refs = 0)
+        : moneypunct<_CharT, _International>(__refs) {init(__nm.c_str());}
+
+protected:
+    _LIBCPP_ALWAYS_INLINE
+    ~moneypunct_byname() {}
+
+    virtual char_type   do_decimal_point() const {return __decimal_point_;}
+    virtual char_type   do_thousands_sep() const {return __thousands_sep_;}
+    virtual string      do_grouping()      const {return __grouping_;}
+    virtual string_type do_curr_symbol()   const {return __curr_symbol_;}
+    virtual string_type do_positive_sign() const {return __positive_sign_;}
+    virtual string_type do_negative_sign() const {return __negative_sign_;}
+    virtual int         do_frac_digits()   const {return __frac_digits_;}
+    virtual pattern     do_pos_format()    const {return __pos_format_;}
+    virtual pattern     do_neg_format()    const {return __neg_format_;}
+
+private:
+    char_type   __decimal_point_;
+    char_type   __thousands_sep_;
+    string      __grouping_;
+    string_type __curr_symbol_;
+    string_type __positive_sign_;
+    string_type __negative_sign_;
+    int         __frac_digits_;
+    pattern     __pos_format_;
+    pattern     __neg_format_;
+
+    void init(const char*);
+};
+
+template<> void moneypunct_byname<char, false>::init(const char*);
+template<> void moneypunct_byname<char, true>::init(const char*);
+template<> void moneypunct_byname<wchar_t, false>::init(const char*);
+template<> void moneypunct_byname<wchar_t, true>::init(const char*);
+
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS moneypunct_byname<char, false>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS moneypunct_byname<char, true>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS moneypunct_byname<wchar_t, false>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS moneypunct_byname<wchar_t, true>)
+
+// money_get
+
+template <class _CharT>
+class __money_get
+{
+protected:
+    typedef _CharT                  char_type;
+    typedef basic_string<char_type> string_type;
+
+    _LIBCPP_ALWAYS_INLINE __money_get() {}
+
+    static void __gather_info(bool __intl, const locale& __loc,
+                              money_base::pattern& __pat, char_type& __dp,
+                              char_type& __ts, string& __grp,
+                              string_type& __sym, string_type& __psn,
+                              string_type& __nsn, int& __fd);
+};
+
+template <class _CharT>
+void
+__money_get<_CharT>::__gather_info(bool __intl, const locale& __loc,
+                                   money_base::pattern& __pat, char_type& __dp,
+                                   char_type& __ts, string& __grp,
+                                   string_type& __sym, string_type& __psn,
+                                   string_type& __nsn, int& __fd)
+{
+    if (__intl)
+    {
+        const moneypunct<char_type, true>& __mp =
+            use_facet<moneypunct<char_type, true> >(__loc);
+        __pat = __mp.neg_format();
+        __nsn = __mp.negative_sign();
+        __psn = __mp.positive_sign();
+        __dp = __mp.decimal_point();
+        __ts = __mp.thousands_sep();
+        __grp = __mp.grouping();
+        __sym = __mp.curr_symbol();
+        __fd = __mp.frac_digits();
+    }
+    else
+    {
+        const moneypunct<char_type, false>& __mp =
+            use_facet<moneypunct<char_type, false> >(__loc);
+        __pat = __mp.neg_format();
+        __nsn = __mp.negative_sign();
+        __psn = __mp.positive_sign();
+        __dp = __mp.decimal_point();
+        __ts = __mp.thousands_sep();
+        __grp = __mp.grouping();
+        __sym = __mp.curr_symbol();
+        __fd = __mp.frac_digits();
+    }
+}
+
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS __money_get<char>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS __money_get<wchar_t>)
+
+template <class _CharT, class _InputIterator = istreambuf_iterator<_CharT> >
+class _LIBCPP_TYPE_VIS_ONLY money_get
+    : public locale::facet,
+      private __money_get<_CharT>
+{
+public:
+    typedef _CharT                  char_type;
+    typedef _InputIterator          iter_type;
+    typedef basic_string<char_type> string_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit money_get(size_t __refs = 0)
+        : locale::facet(__refs) {}
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get(iter_type __b, iter_type __e, bool __intl, ios_base& __iob,
+                  ios_base::iostate& __err, long double& __v) const
+    {
+        return do_get(__b, __e, __intl, __iob, __err, __v);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type get(iter_type __b, iter_type __e, bool __intl, ios_base& __iob,
+                  ios_base::iostate& __err, string_type& __v) const
+    {
+        return do_get(__b, __e, __intl, __iob, __err, __v);
+    }
+
+    static locale::id id;
+
+protected:
+
+    _LIBCPP_ALWAYS_INLINE
+    ~money_get() {}
+
+    virtual iter_type do_get(iter_type __b, iter_type __e, bool __intl,
+                             ios_base& __iob, ios_base::iostate& __err,
+                             long double& __v) const;
+    virtual iter_type do_get(iter_type __b, iter_type __e, bool __intl,
+                             ios_base& __iob, ios_base::iostate& __err,
+                             string_type& __v) const;
+
+private:
+    static bool __do_get(iter_type& __b, iter_type __e,
+                         bool __intl, const locale& __loc,
+                         ios_base::fmtflags __flags, ios_base::iostate& __err,
+                         bool& __neg, const ctype<char_type>& __ct,
+                         unique_ptr<char_type, void(*)(void*)>& __wb,
+                         char_type*& __wn, char_type* __we);
+};
+
+template <class _CharT, class _InputIterator>
+locale::id
+money_get<_CharT, _InputIterator>::id;
+
+_LIBCPP_FUNC_VIS void __do_nothing(void*);
+
+template <class _Tp>
+_LIBCPP_HIDDEN
+void
+__double_or_nothing(unique_ptr<_Tp, void(*)(void*)>& __b, _Tp*& __n, _Tp*& __e)
+{
+    bool __owns = __b.get_deleter() != __do_nothing;
+    size_t __cur_cap = static_cast<size_t>(__e-__b.get()) * sizeof(_Tp);
+    size_t __new_cap = __cur_cap < numeric_limits<size_t>::max() / 2 ?
+                       2 * __cur_cap : numeric_limits<size_t>::max();
+    if (__new_cap == 0)
+        __new_cap = sizeof(_Tp);
+    size_t __n_off = static_cast<size_t>(__n - __b.get());
+    _Tp* __t = (_Tp*)realloc(__owns ? __b.get() : 0, __new_cap);
+    if (__t == 0)
+        __throw_bad_alloc();
+    if (__owns)
+        __b.release();
+    __b = unique_ptr<_Tp, void(*)(void*)>(__t, free);
+    __new_cap /= sizeof(_Tp);
+    __n = __b.get() + __n_off;
+    __e = __b.get() + __new_cap;
+}
+
+// true == success
+template <class _CharT, class _InputIterator>
+bool
+money_get<_CharT, _InputIterator>::__do_get(iter_type& __b, iter_type __e,
+                                            bool __intl, const locale& __loc,
+                                            ios_base::fmtflags __flags,
+                                            ios_base::iostate& __err,
+                                            bool& __neg,
+                                            const ctype<char_type>& __ct,
+                                            unique_ptr<char_type, void(*)(void*)>& __wb,
+                                            char_type*& __wn, char_type* __we)
+{
+    const unsigned __bz = 100;
+    unsigned __gbuf[__bz];
+    unique_ptr<unsigned, void(*)(void*)> __gb(__gbuf, __do_nothing);
+    unsigned* __gn = __gb.get();
+    unsigned* __ge = __gn + __bz;
+    money_base::pattern __pat;
+    char_type __dp;
+    char_type __ts;
+    string __grp;
+    string_type __sym;
+    string_type __psn;
+    string_type __nsn;
+    // Capture the spaces read into money_base::{space,none} so they
+    // can be compared to initial spaces in __sym.
+    string_type __spaces;
+    int __fd;
+    __money_get<_CharT>::__gather_info(__intl, __loc, __pat, __dp, __ts, __grp,
+                                       __sym, __psn, __nsn, __fd);
+    const string_type* __trailing_sign = 0;
+    __wn = __wb.get();
+    for (unsigned __p = 0; __p < 4 && __b != __e; ++__p)
+    {
+        switch (__pat.field[__p])
+        {
+        case money_base::space:
+            if (__p != 3)
+            {
+                if (__ct.is(ctype_base::space, *__b))
+                    __spaces.push_back(*__b++);
+                else
+                {
+                    __err |= ios_base::failbit;
+                    return false;
+                }
+            }
+            // drop through
+        case money_base::none:
+            if (__p != 3)
+            {
+                while (__b != __e && __ct.is(ctype_base::space, *__b))
+                    __spaces.push_back(*__b++);
+            }
+            break;
+        case money_base::sign:
+            if (__psn.size() + __nsn.size() > 0)
+            {
+                if (__psn.size() == 0 || __nsn.size() == 0)
+                {   // sign is optional
+                    if (__psn.size() > 0)
+                    {   // __nsn.size() == 0
+                        if (*__b == __psn[0])
+                        {
+                            ++__b;
+                            if (__psn.size() > 1)
+                                __trailing_sign = &__psn;
+                        }
+                        else
+                            __neg = true;
+                    }
+                    else if (*__b == __nsn[0])  // __nsn.size() > 0 &&  __psn.size() == 0
+                    {
+                        ++__b;
+                        __neg = true;
+                        if (__nsn.size() > 1)
+                            __trailing_sign = &__nsn;
+                    }
+                }
+                else  // sign is required
+                {
+                    if (*__b == __psn[0])
+                    {
+                        ++__b;
+                        if (__psn.size() > 1)
+                            __trailing_sign = &__psn;
+                    }
+                    else if (*__b == __nsn[0])
+                    {
+                        ++__b;
+                        __neg = true;
+                        if (__nsn.size() > 1)
+                            __trailing_sign = &__nsn;
+                    }
+                    else
+                    {
+                        __err |= ios_base::failbit;
+                        return false;
+                    }
+                }
+            }
+            break;
+        case money_base::symbol:
+            {
+            bool __more_needed = __trailing_sign ||
+                                 (__p < 2)       ||
+                                 (__p == 2 && __pat.field[3] != static_cast<char>(money_base::none));
+            bool __sb = (__flags & ios_base::showbase) != 0;
+            if (__sb || __more_needed)
+            {
+                typename string_type::const_iterator __sym_space_end = __sym.begin();
+                if (__p > 0 && (__pat.field[__p - 1] == money_base::none ||
+                                __pat.field[__p - 1] == money_base::space)) {
+                    // Match spaces we've already read against spaces at
+                    // the beginning of __sym.
+                    while (__sym_space_end != __sym.end() &&
+                           __ct.is(ctype_base::space, *__sym_space_end))
+                        ++__sym_space_end;
+                    const size_t __num_spaces = __sym_space_end - __sym.begin();
+                    if (__num_spaces > __spaces.size() ||
+                        !equal(__spaces.end() - __num_spaces, __spaces.end(),
+                               __sym.begin())) {
+                        // No match. Put __sym_space_end back at the
+                        // beginning of __sym, which will prevent a
+                        // match in the next loop.
+                        __sym_space_end = __sym.begin();
+                    }
+                }
+                typename string_type::const_iterator __sym_curr_char = __sym_space_end;
+                while (__sym_curr_char != __sym.end() && __b != __e &&
+                       *__b == *__sym_curr_char) {
+                    ++__b;
+                    ++__sym_curr_char;
+                }
+                if (__sb && __sym_curr_char != __sym.end())
+                {
+                    __err |= ios_base::failbit;
+                    return false;
+                }
+            }
+            }
+            break;
+        case money_base::value:
+            {
+            unsigned __ng = 0;
+            for (; __b != __e; ++__b)
+            {
+                char_type __c = *__b;
+                if (__ct.is(ctype_base::digit, __c))
+                {
+                    if (__wn == __we)
+                        __double_or_nothing(__wb, __wn, __we);
+                    *__wn++ = __c;
+                    ++__ng;
+                }
+                else if (__grp.size() > 0 && __ng > 0 && __c == __ts)
+                {
+                    if (__gn == __ge)
+                        __double_or_nothing(__gb, __gn, __ge);
+                    *__gn++ = __ng;
+                    __ng = 0;
+                }
+                else
+                    break;
+            }
+            if (__gb.get() != __gn && __ng > 0)
+            {
+                if (__gn == __ge)
+                    __double_or_nothing(__gb, __gn, __ge);
+                *__gn++ = __ng;
+            }
+            if (__fd > 0)
+            {
+                if (__b == __e || *__b != __dp)
+                {
+                    __err |= ios_base::failbit;
+                    return false;
+                }
+                for (++__b; __fd > 0; --__fd, ++__b)
+                {
+                    if (__b == __e || !__ct.is(ctype_base::digit, *__b))
+                    {
+                        __err |= ios_base::failbit;
+                        return false;
+                    }
+                    if (__wn == __we)
+                        __double_or_nothing(__wb, __wn, __we);
+                    *__wn++ = *__b;
+                }
+            }
+            if (__wn == __wb.get())
+            {
+                __err |= ios_base::failbit;
+                return false;
+            }
+            }
+            break;
+        }
+    }
+    if (__trailing_sign)
+    {
+        for (unsigned __i = 1; __i < __trailing_sign->size(); ++__i, ++__b)
+        {
+            if (__b == __e || *__b != (*__trailing_sign)[__i])
+            {
+                __err |= ios_base::failbit;
+                return false;
+            }
+        }
+    }
+    if (__gb.get() != __gn)
+    {
+        ios_base::iostate __et = ios_base::goodbit;
+        __check_grouping(__grp, __gb.get(), __gn, __et);
+        if (__et)
+        {
+            __err |= ios_base::failbit;
+            return false;
+        }
+    }
+    return true;
+}
+
+template <class _CharT, class _InputIterator>
+_InputIterator
+money_get<_CharT, _InputIterator>::do_get(iter_type __b, iter_type __e,
+                                          bool __intl, ios_base& __iob,
+                                          ios_base::iostate& __err,
+                                          long double& __v) const
+{
+    const int __bz = 100;
+    char_type __wbuf[__bz];
+    unique_ptr<char_type, void(*)(void*)> __wb(__wbuf, __do_nothing);
+    char_type* __wn;
+    char_type* __we = __wbuf + __bz;
+    locale __loc = __iob.getloc();
+    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__loc);
+    bool __neg = false;
+    if (__do_get(__b, __e, __intl, __loc, __iob.flags(), __err, __neg, __ct,
+                 __wb, __wn, __we))
+    {
+        const char __src[] = "0123456789";
+        char_type __atoms[sizeof(__src)-1];
+        __ct.widen(__src, __src + (sizeof(__src)-1), __atoms);
+        char __nbuf[__bz];
+        char* __nc = __nbuf;
+        unique_ptr<char, void(*)(void*)> __h(0, free);
+        if (__wn - __wb.get() > __bz-2)
+        {
+            __h.reset((char*)malloc(static_cast<size_t>(__wn - __wb.get() + 2)));
+            if (__h.get() == 0)
+                __throw_bad_alloc();
+            __nc = __h.get();
+        }
+        if (__neg)
+            *__nc++ = '-';
+        for (const char_type* __w = __wb.get(); __w < __wn; ++__w, ++__nc)
+            *__nc = __src[find(__atoms, _VSTD::end(__atoms), *__w) - __atoms];
+        *__nc = char();
+        if (sscanf(__nbuf, "%Lf", &__v) != 1)
+            __throw_runtime_error("money_get error");
+    }
+    if (__b == __e)
+        __err |= ios_base::eofbit;
+    return __b;
+}
+
+template <class _CharT, class _InputIterator>
+_InputIterator
+money_get<_CharT, _InputIterator>::do_get(iter_type __b, iter_type __e,
+                                          bool __intl, ios_base& __iob,
+                                          ios_base::iostate& __err,
+                                          string_type& __v) const
+{
+    const int __bz = 100;
+    char_type __wbuf[__bz];
+    unique_ptr<char_type, void(*)(void*)> __wb(__wbuf, __do_nothing);
+    char_type* __wn;
+    char_type* __we = __wbuf + __bz;
+    locale __loc = __iob.getloc();
+    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__loc);
+    bool __neg = false;
+    if (__do_get(__b, __e, __intl, __loc, __iob.flags(), __err, __neg, __ct,
+                 __wb, __wn, __we))
+    {
+        __v.clear();
+        if (__neg)
+            __v.push_back(__ct.widen('-'));
+        char_type __z = __ct.widen('0');
+        char_type* __w;
+        for (__w = __wb.get(); __w < __wn-1; ++__w)
+            if (*__w != __z)
+                break;
+        __v.append(__w, __wn);
+    }
+    if (__b == __e)
+        __err |= ios_base::eofbit;
+    return __b;
+}
+
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS money_get<char>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS money_get<wchar_t>)
+
+// money_put
+
+template <class _CharT>
+class __money_put
+{
+protected:
+    typedef _CharT                  char_type;
+    typedef basic_string<char_type> string_type;
+
+    _LIBCPP_ALWAYS_INLINE __money_put() {}
+
+    static void __gather_info(bool __intl, bool __neg, const locale& __loc,
+                              money_base::pattern& __pat, char_type& __dp,
+                              char_type& __ts, string& __grp,
+                              string_type& __sym, string_type& __sn,
+                              int& __fd);
+    static void __format(char_type* __mb, char_type*& __mi, char_type*& __me,
+                         ios_base::fmtflags __flags,
+                         const char_type* __db, const char_type* __de,
+                         const ctype<char_type>& __ct, bool __neg,
+                         const money_base::pattern& __pat, char_type __dp,
+                         char_type __ts, const string& __grp,
+                         const string_type& __sym, const string_type& __sn,
+                         int __fd);
+};
+
+template <class _CharT>
+void
+__money_put<_CharT>::__gather_info(bool __intl, bool __neg, const locale& __loc,
+                                   money_base::pattern& __pat, char_type& __dp,
+                                   char_type& __ts, string& __grp,
+                                   string_type& __sym, string_type& __sn,
+                                   int& __fd)
+{
+    if (__intl)
+    {
+        const moneypunct<char_type, true>& __mp =
+            use_facet<moneypunct<char_type, true> >(__loc);
+        if (__neg)
+        {
+            __pat = __mp.neg_format();
+            __sn = __mp.negative_sign();
+        }
+        else
+        {
+            __pat = __mp.pos_format();
+            __sn = __mp.positive_sign();
+        }
+        __dp = __mp.decimal_point();
+        __ts = __mp.thousands_sep();
+        __grp = __mp.grouping();
+        __sym = __mp.curr_symbol();
+        __fd = __mp.frac_digits();
+    }
+    else
+    {
+        const moneypunct<char_type, false>& __mp =
+            use_facet<moneypunct<char_type, false> >(__loc);
+        if (__neg)
+        {
+            __pat = __mp.neg_format();
+            __sn = __mp.negative_sign();
+        }
+        else
+        {
+            __pat = __mp.pos_format();
+            __sn = __mp.positive_sign();
+        }
+        __dp = __mp.decimal_point();
+        __ts = __mp.thousands_sep();
+        __grp = __mp.grouping();
+        __sym = __mp.curr_symbol();
+        __fd = __mp.frac_digits();
+    }
+}
+
+template <class _CharT>
+void
+__money_put<_CharT>::__format(char_type* __mb, char_type*& __mi, char_type*& __me,
+                              ios_base::fmtflags __flags,
+                              const char_type* __db, const char_type* __de,
+                              const ctype<char_type>& __ct, bool __neg,
+                              const money_base::pattern& __pat, char_type __dp,
+                              char_type __ts, const string& __grp,
+                              const string_type& __sym, const string_type& __sn,
+                              int __fd)
+{
+    __me = __mb;
+    for (unsigned __p = 0; __p < 4; ++__p)
+    {
+        switch (__pat.field[__p])
+        {
+        case money_base::none:
+            __mi = __me;
+            break;
+        case money_base::space:
+            __mi = __me;
+            *__me++ = __ct.widen(' ');
+            break;
+        case money_base::sign:
+            if (!__sn.empty())
+                *__me++ = __sn[0];
+            break;
+        case money_base::symbol:
+            if (!__sym.empty() && (__flags & ios_base::showbase))
+                __me = _VSTD::copy(__sym.begin(), __sym.end(), __me);
+            break;
+        case money_base::value:
+            {
+            // remember start of value so we can reverse it
+            char_type* __t = __me;
+            // find beginning of digits
+            if (__neg)
+                ++__db;
+            // find end of digits
+            const char_type* __d;
+            for (__d = __db; __d < __de; ++__d)
+                if (!__ct.is(ctype_base::digit, *__d))
+                    break;
+            // print fractional part
+            if (__fd > 0)
+            {
+                int __f;
+                for (__f = __fd; __d > __db && __f > 0; --__f)
+                    *__me++ = *--__d;
+                char_type __z = __f > 0 ? __ct.widen('0') : char_type();
+                for (; __f > 0; --__f)
+                    *__me++ = __z;
+                *__me++ = __dp;
+            }
+            // print units part
+            if (__d == __db)
+            {
+                *__me++ = __ct.widen('0');
+            }
+            else
+            {
+                unsigned __ng = 0;
+                unsigned __ig = 0;
+                unsigned __gl = __grp.empty() ? numeric_limits<unsigned>::max()
+                                              : static_cast<unsigned>(__grp[__ig]);
+                while (__d != __db)
+                {
+                    if (__ng == __gl)
+                    {
+                        *__me++ = __ts;
+                        __ng = 0;
+                        if (++__ig < __grp.size())
+                            __gl = __grp[__ig] == numeric_limits<char>::max() ?
+                                        numeric_limits<unsigned>::max() :
+                                        static_cast<unsigned>(__grp[__ig]);
+                    }
+                    *__me++ = *--__d;
+                    ++__ng;
+                }
+            }
+            // reverse it
+            reverse(__t, __me);
+            }
+            break;
+        }
+    }
+    // print rest of sign, if any
+    if (__sn.size() > 1)
+        __me = _VSTD::copy(__sn.begin()+1, __sn.end(), __me);
+    // set alignment
+    if ((__flags & ios_base::adjustfield) == ios_base::left)
+        __mi = __me;
+    else if ((__flags & ios_base::adjustfield) != ios_base::internal)
+        __mi = __mb;
+}
+
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS __money_put<char>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS __money_put<wchar_t>)
+
+template <class _CharT, class _OutputIterator = ostreambuf_iterator<_CharT> >
+class _LIBCPP_TYPE_VIS_ONLY money_put
+    : public locale::facet,
+      private __money_put<_CharT>
+{
+public:
+    typedef _CharT                  char_type;
+    typedef _OutputIterator         iter_type;
+    typedef basic_string<char_type> string_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit money_put(size_t __refs = 0)
+        : locale::facet(__refs) {}
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type put(iter_type __s, bool __intl, ios_base& __iob, char_type __fl,
+                  long double __units) const
+    {
+        return do_put(__s, __intl, __iob, __fl, __units);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    iter_type put(iter_type __s, bool __intl, ios_base& __iob, char_type __fl,
+                  const string_type& __digits) const
+    {
+        return do_put(__s, __intl, __iob, __fl, __digits);
+    }
+
+    static locale::id id;
+
+protected:
+    _LIBCPP_ALWAYS_INLINE
+    ~money_put() {}
+
+    virtual iter_type do_put(iter_type __s, bool __intl, ios_base& __iob,
+                             char_type __fl, long double __units) const;
+    virtual iter_type do_put(iter_type __s, bool __intl, ios_base& __iob,
+                             char_type __fl, const string_type& __digits) const;
+};
+
+template <class _CharT, class _OutputIterator>
+locale::id
+money_put<_CharT, _OutputIterator>::id;
+
+template <class _CharT, class _OutputIterator>
+_OutputIterator
+money_put<_CharT, _OutputIterator>::do_put(iter_type __s, bool __intl,
+                                           ios_base& __iob, char_type __fl,
+                                           long double __units) const
+{
+    // convert to char
+    const size_t __bs = 100;
+    char __buf[__bs];
+    char* __bb = __buf;
+    char_type __digits[__bs];
+    char_type* __db = __digits;
+    size_t __n = static_cast<size_t>(snprintf(__bb, __bs, "%.0Lf", __units));
+    unique_ptr<char, void(*)(void*)> __hn(0, free);
+    unique_ptr<char_type, void(*)(void*)> __hd(0, free);
+    // secure memory for digit storage
+    if (__n > __bs-1)
+    {
+#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
+        __n = static_cast<size_t>(asprintf_l(&__bb, _LIBCPP_GET_C_LOCALE, "%.0Lf", __units));
+#else
+        __n = __asprintf_l(&__bb, _LIBCPP_GET_C_LOCALE, "%.0Lf", __units);
+#endif
+        if (__bb == 0)
+            __throw_bad_alloc();
+        __hn.reset(__bb);
+        __hd.reset((char_type*)malloc(__n * sizeof(char_type)));
+        if (__hd == nullptr)
+            __throw_bad_alloc();
+        __db = __hd.get();
+    }
+    // gather info
+    locale __loc = __iob.getloc();
+    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__loc);
+    __ct.widen(__bb, __bb + __n, __db);
+    bool __neg = __n > 0 && __bb[0] == '-';
+    money_base::pattern __pat;
+    char_type __dp;
+    char_type __ts;
+    string __grp;
+    string_type __sym;
+    string_type __sn;
+    int __fd;
+    this->__gather_info(__intl, __neg, __loc, __pat, __dp, __ts, __grp, __sym, __sn, __fd);
+    // secure memory for formatting
+    char_type __mbuf[__bs];
+    char_type* __mb = __mbuf;
+    unique_ptr<char_type, void(*)(void*)> __hw(0, free);
+    size_t __exn = static_cast<int>(__n) > __fd ?
+                   (__n - static_cast<size_t>(__fd)) * 2 + __sn.size() +
+                    __sym.size() + static_cast<size_t>(__fd) + 1
+                 : __sn.size() + __sym.size() + static_cast<size_t>(__fd) + 2;
+    if (__exn > __bs)
+    {
+        __hw.reset((char_type*)malloc(__exn * sizeof(char_type)));
+        __mb = __hw.get();
+        if (__mb == 0)
+            __throw_bad_alloc();
+    }
+    // format
+    char_type* __mi;
+    char_type* __me;
+    this->__format(__mb, __mi, __me, __iob.flags(),
+                   __db, __db + __n, __ct,
+                   __neg, __pat, __dp, __ts, __grp, __sym, __sn, __fd);
+    return __pad_and_output(__s, __mb, __mi, __me, __iob, __fl);
+}
+
+template <class _CharT, class _OutputIterator>
+_OutputIterator
+money_put<_CharT, _OutputIterator>::do_put(iter_type __s, bool __intl,
+                                           ios_base& __iob, char_type __fl,
+                                           const string_type& __digits) const
+{
+    // gather info
+    locale __loc = __iob.getloc();
+    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__loc);
+    bool __neg = __digits.size() > 0 && __digits[0] == __ct.widen('-');
+    money_base::pattern __pat;
+    char_type __dp;
+    char_type __ts;
+    string __grp;
+    string_type __sym;
+    string_type __sn;
+    int __fd;
+    this->__gather_info(__intl, __neg, __loc, __pat, __dp, __ts, __grp, __sym, __sn, __fd);
+    // secure memory for formatting
+    char_type __mbuf[100];
+    char_type* __mb = __mbuf;
+    unique_ptr<char_type, void(*)(void*)> __h(0, free);
+    size_t __exn = static_cast<int>(__digits.size()) > __fd ?
+                   (__digits.size() - static_cast<size_t>(__fd)) * 2 +
+                    __sn.size() + __sym.size() + static_cast<size_t>(__fd) + 1
+                 : __sn.size() + __sym.size() + static_cast<size_t>(__fd) + 2;
+    if (__exn > 100)
+    {
+        __h.reset((char_type*)malloc(__exn * sizeof(char_type)));
+        __mb = __h.get();
+        if (__mb == 0)
+            __throw_bad_alloc();
+    }
+    // format
+    char_type* __mi;
+    char_type* __me;
+    this->__format(__mb, __mi, __me, __iob.flags(),
+                   __digits.data(), __digits.data() + __digits.size(), __ct,
+                   __neg, __pat, __dp, __ts, __grp, __sym, __sn, __fd);
+    return __pad_and_output(__s, __mb, __mi, __me, __iob, __fl);
+}
+
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS money_put<char>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS money_put<wchar_t>)
+
+// messages
+
+class _LIBCPP_TYPE_VIS messages_base
+{
+public:
+    typedef ptrdiff_t catalog;
+
+    _LIBCPP_ALWAYS_INLINE messages_base() {}
+};
+
+template <class _CharT>
+class _LIBCPP_TYPE_VIS_ONLY messages
+    : public locale::facet,
+      public messages_base
+{
+public:
+    typedef _CharT               char_type;
+    typedef basic_string<_CharT> string_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit messages(size_t __refs = 0)
+        : locale::facet(__refs) {}
+
+    _LIBCPP_ALWAYS_INLINE
+    catalog open(const basic_string<char>& __nm, const locale& __loc) const
+    {
+        return do_open(__nm, __loc);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    string_type get(catalog __c, int __set, int __msgid,
+                    const string_type& __dflt) const
+    {
+        return do_get(__c, __set, __msgid, __dflt);
+    }
+
+    _LIBCPP_ALWAYS_INLINE
+    void close(catalog __c) const
+    {
+        do_close(__c);
+    }
+
+    static locale::id id;
+
+protected:
+    _LIBCPP_ALWAYS_INLINE
+    ~messages() {}
+
+    virtual catalog do_open(const basic_string<char>&, const locale&) const;
+    virtual string_type do_get(catalog, int __set, int __msgid,
+                               const string_type& __dflt) const;
+    virtual void do_close(catalog) const;
+};
+
+template <class _CharT>
+locale::id
+messages<_CharT>::id;
+
+template <class _CharT>
+typename messages<_CharT>::catalog
+messages<_CharT>::do_open(const basic_string<char>& __nm, const locale&) const
+{
+#ifdef _LIBCPP_HAS_CATOPEN
+    catalog __cat = (catalog)catopen(__nm.c_str(), NL_CAT_LOCALE);
+    if (__cat != -1)
+        __cat = static_cast<catalog>((static_cast<size_t>(__cat) >> 1));
+    return __cat;
+#else // !_LIBCPP_HAS_CATOPEN
+    return -1;
+#endif // _LIBCPP_HAS_CATOPEN
+}
+
+template <class _CharT>
+typename messages<_CharT>::string_type
+messages<_CharT>::do_get(catalog __c, int __set, int __msgid,
+                         const string_type& __dflt) const
+{
+#ifdef _LIBCPP_HAS_CATOPEN
+    string __ndflt;
+    __narrow_to_utf8<sizeof(char_type)*__CHAR_BIT__>()(back_inserter(__ndflt),
+                                                       __dflt.c_str(),
+                                                       __dflt.c_str() + __dflt.size());
+    if (__c != -1)
+        __c <<= 1;
+    nl_catd __cat = (nl_catd)__c;
+    char* __n = catgets(__cat, __set, __msgid, __ndflt.c_str());
+    string_type __w;
+    __widen_from_utf8<sizeof(char_type)*__CHAR_BIT__>()(back_inserter(__w),
+                                                        __n, __n + strlen(__n));
+    return __w;
+#else // !_LIBCPP_HAS_CATOPEN
+    return __dflt;
+#endif // _LIBCPP_HAS_CATOPEN
+}
+
+template <class _CharT>
+void
+messages<_CharT>::do_close(catalog __c) const
+{
+#ifdef _LIBCPP_HAS_CATOPEN
+    if (__c != -1)
+        __c <<= 1;
+    nl_catd __cat = (nl_catd)__c;
+    catclose(__cat);
+#endif // _LIBCPP_HAS_CATOPEN
+}
+
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS messages<char>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS messages<wchar_t>)
+
+template <class _CharT>
+class _LIBCPP_TYPE_VIS_ONLY messages_byname
+    : public messages<_CharT>
+{
+public:
+    typedef messages_base::catalog catalog;
+    typedef basic_string<_CharT> string_type;
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit messages_byname(const char*, size_t __refs = 0)
+        : messages<_CharT>(__refs) {}
+
+    _LIBCPP_ALWAYS_INLINE
+    explicit messages_byname(const string&, size_t __refs = 0)
+        : messages<_CharT>(__refs) {}
+
+protected:
+    _LIBCPP_ALWAYS_INLINE
+    ~messages_byname() {}
+};
+
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS messages_byname<char>)
+_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_TYPE_VIS messages_byname<wchar_t>)
+
+template<class _Codecvt, class _Elem = wchar_t,
+         class _Wide_alloc = allocator<_Elem>,
+         class _Byte_alloc = allocator<char> >
+class _LIBCPP_TYPE_VIS_ONLY wstring_convert
+{
+public:
+    typedef basic_string<char, char_traits<char>, _Byte_alloc>   byte_string;
+    typedef basic_string<_Elem, char_traits<_Elem>, _Wide_alloc> wide_string;
+    typedef typename _Codecvt::state_type                        state_type;
+    typedef typename wide_string::traits_type::int_type          int_type;
+
+private:
+    byte_string __byte_err_string_;
+    wide_string __wide_err_string_;
+    _Codecvt* __cvtptr_;
+    state_type __cvtstate_;
+    size_t __cvtcount_;
+
+    wstring_convert(const wstring_convert& __wc);
+    wstring_convert& operator=(const wstring_convert& __wc);
+public:
+    _LIBCPP_EXPLICIT_AFTER_CXX11 wstring_convert(_Codecvt* __pcvt = new _Codecvt);
+    wstring_convert(_Codecvt* __pcvt, state_type __state);
+    _LIBCPP_EXPLICIT_AFTER_CXX11 wstring_convert(const byte_string& __byte_err,
+                    const wide_string& __wide_err = wide_string());
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    wstring_convert(wstring_convert&& __wc);
+#endif
+    ~wstring_convert();
+
+    _LIBCPP_ALWAYS_INLINE
+    wide_string from_bytes(char __byte)
+        {return from_bytes(&__byte, &__byte+1);}
+    _LIBCPP_ALWAYS_INLINE
+    wide_string from_bytes(const char* __ptr)
+        {return from_bytes(__ptr, __ptr + char_traits<char>::length(__ptr));}
+    _LIBCPP_ALWAYS_INLINE
+    wide_string from_bytes(const byte_string& __str)
+        {return from_bytes(__str.data(), __str.data() + __str.size());}
+    wide_string from_bytes(const char* __first, const char* __last);
+
+    _LIBCPP_ALWAYS_INLINE
+    byte_string to_bytes(_Elem __wchar)
+        {return to_bytes(&__wchar, &__wchar+1);}
+    _LIBCPP_ALWAYS_INLINE
+    byte_string to_bytes(const _Elem* __wptr)
+        {return to_bytes(__wptr, __wptr + char_traits<_Elem>::length(__wptr));}
+    _LIBCPP_ALWAYS_INLINE
+    byte_string to_bytes(const wide_string& __wstr)
+        {return to_bytes(__wstr.data(), __wstr.data() + __wstr.size());}
+    byte_string to_bytes(const _Elem* __first, const _Elem* __last);
+
+    _LIBCPP_ALWAYS_INLINE
+    size_t converted() const _NOEXCEPT {return __cvtcount_;}
+    _LIBCPP_ALWAYS_INLINE
+    state_type state() const {return __cvtstate_;}
+};
+
+template<class _Codecvt, class _Elem, class _Wide_alloc, class _Byte_alloc>
+inline _LIBCPP_ALWAYS_INLINE
+wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::
+    wstring_convert(_Codecvt* __pcvt)
+        : __cvtptr_(__pcvt), __cvtstate_(), __cvtcount_(0)
+{
+}
+
+template<class _Codecvt, class _Elem, class _Wide_alloc, class _Byte_alloc>
+inline _LIBCPP_ALWAYS_INLINE
+wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::
+    wstring_convert(_Codecvt* __pcvt, state_type __state)
+        : __cvtptr_(__pcvt), __cvtstate_(__state), __cvtcount_(0)
+{
+}
+
+template<class _Codecvt, class _Elem, class _Wide_alloc, class _Byte_alloc>
+wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::
+    wstring_convert(const byte_string& __byte_err, const wide_string& __wide_err)
+        : __byte_err_string_(__byte_err), __wide_err_string_(__wide_err),
+          __cvtstate_(), __cvtcount_(0)
+{
+    __cvtptr_ = new _Codecvt;
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template<class _Codecvt, class _Elem, class _Wide_alloc, class _Byte_alloc>
+inline _LIBCPP_ALWAYS_INLINE
+wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::
+    wstring_convert(wstring_convert&& __wc)
+        : __byte_err_string_(_VSTD::move(__wc.__byte_err_string_)),
+          __wide_err_string_(_VSTD::move(__wc.__wide_err_string_)),
+          __cvtptr_(__wc.__cvtptr_),
+          __cvtstate_(__wc.__cvtstate_), __cvtcount_(__wc.__cvtstate_)
+{
+    __wc.__cvtptr_ = nullptr;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template<class _Codecvt, class _Elem, class _Wide_alloc, class _Byte_alloc>
+wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::~wstring_convert()
+{
+    delete __cvtptr_;
+}
+
+template<class _Codecvt, class _Elem, class _Wide_alloc, class _Byte_alloc>
+typename wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::wide_string
+wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::
+    from_bytes(const char* __frm, const char* __frm_end)
+{
+    __cvtcount_ = 0;
+    if (__cvtptr_ != nullptr)
+    {
+        wide_string __ws(2*(__frm_end - __frm), _Elem());
+        if (__frm != __frm_end)
+            __ws.resize(__ws.capacity());
+        codecvt_base::result __r = codecvt_base::ok;
+        state_type __st = __cvtstate_;
+        if (__frm != __frm_end)
+        {
+            _Elem* __to = &__ws[0];
+            _Elem* __to_end = __to + __ws.size();
+            const char* __frm_nxt;
+            do
+            {
+                _Elem* __to_nxt;
+                __r = __cvtptr_->in(__st, __frm, __frm_end, __frm_nxt,
+                                          __to, __to_end, __to_nxt);
+                __cvtcount_ += __frm_nxt - __frm;
+                if (__frm_nxt == __frm)
+                {
+                    __r = codecvt_base::error;
+                }
+                else if (__r == codecvt_base::noconv)
+                {
+                    __ws.resize(__to - &__ws[0]);
+                    // This only gets executed if _Elem is char
+                    __ws.append((const _Elem*)__frm, (const _Elem*)__frm_end);
+                    __frm = __frm_nxt;
+                    __r = codecvt_base::ok;
+                }
+                else if (__r == codecvt_base::ok)
+                {
+                    __ws.resize(__to_nxt - &__ws[0]);
+                    __frm = __frm_nxt;
+                }
+                else if (__r == codecvt_base::partial)
+                {
+                    ptrdiff_t __s = __to_nxt - &__ws[0];
+                    __ws.resize(2 * __s);
+                    __to = &__ws[0] + __s;
+                    __to_end = &__ws[0] + __ws.size();
+                    __frm = __frm_nxt;
+                }
+            } while (__r == codecvt_base::partial && __frm_nxt < __frm_end);
+        }
+        if (__r == codecvt_base::ok)
+            return __ws;
+    }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__wide_err_string_.empty())
+        throw range_error("wstring_convert: from_bytes error");
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __wide_err_string_;
+}
+
+template<class _Codecvt, class _Elem, class _Wide_alloc, class _Byte_alloc>
+typename wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::byte_string
+wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::
+    to_bytes(const _Elem* __frm, const _Elem* __frm_end)
+{
+    __cvtcount_ = 0;
+    if (__cvtptr_ != nullptr)
+    {
+        byte_string __bs(2*(__frm_end - __frm), char());
+        if (__frm != __frm_end)
+            __bs.resize(__bs.capacity());
+        codecvt_base::result __r = codecvt_base::ok;
+        state_type __st = __cvtstate_;
+        if (__frm != __frm_end)
+        {
+            char* __to = &__bs[0];
+            char* __to_end = __to + __bs.size();
+            const _Elem* __frm_nxt;
+            do
+            {
+                char* __to_nxt;
+                __r = __cvtptr_->out(__st, __frm, __frm_end, __frm_nxt,
+                                           __to, __to_end, __to_nxt);
+                __cvtcount_ += __frm_nxt - __frm;
+                if (__frm_nxt == __frm)
+                {
+                    __r = codecvt_base::error;
+                }
+                else if (__r == codecvt_base::noconv)
+                {
+                    __bs.resize(__to - &__bs[0]);
+                    // This only gets executed if _Elem is char
+                    __bs.append((const char*)__frm, (const char*)__frm_end);
+                    __frm = __frm_nxt;
+                    __r = codecvt_base::ok;
+                }
+                else if (__r == codecvt_base::ok)
+                {
+                    __bs.resize(__to_nxt - &__bs[0]);
+                    __frm = __frm_nxt;
+                }
+                else if (__r == codecvt_base::partial)
+                {
+                    ptrdiff_t __s = __to_nxt - &__bs[0];
+                    __bs.resize(2 * __s);
+                    __to = &__bs[0] + __s;
+                    __to_end = &__bs[0] + __bs.size();
+                    __frm = __frm_nxt;
+                }
+            } while (__r == codecvt_base::partial && __frm_nxt < __frm_end);
+        }
+        if (__r == codecvt_base::ok)
+        {
+            size_t __s = __bs.size();
+            __bs.resize(__bs.capacity());
+            char* __to = &__bs[0] + __s;
+            char* __to_end = __to + __bs.size();
+            do
+            {
+                char* __to_nxt;
+                __r = __cvtptr_->unshift(__st, __to, __to_end, __to_nxt);
+                if (__r == codecvt_base::noconv)
+                {
+                    __bs.resize(__to - &__bs[0]);
+                    __r = codecvt_base::ok;
+                }
+                else if (__r == codecvt_base::ok)
+                {
+                    __bs.resize(__to_nxt - &__bs[0]);
+                }
+                else if (__r == codecvt_base::partial)
+                {
+                    ptrdiff_t __sp = __to_nxt - &__bs[0];
+                    __bs.resize(2 * __sp);
+                    __to = &__bs[0] + __sp;
+                    __to_end = &__bs[0] + __bs.size();
+                }
+            } while (__r == codecvt_base::partial);
+            if (__r == codecvt_base::ok)
+                return __bs;
+        }
+    }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__byte_err_string_.empty())
+        throw range_error("wstring_convert: to_bytes error");
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __byte_err_string_;
+}
+
+template <class _Codecvt, class _Elem = wchar_t, class _Tr = char_traits<_Elem> >
+class _LIBCPP_TYPE_VIS_ONLY wbuffer_convert
+    : public basic_streambuf<_Elem, _Tr>
+{
+public:
+    // types:
+    typedef _Elem                          char_type;
+    typedef _Tr                            traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+    typedef typename _Codecvt::state_type  state_type;
+
+private:
+    char*       __extbuf_;
+    const char* __extbufnext_;
+    const char* __extbufend_;
+    char __extbuf_min_[8];
+    size_t __ebs_;
+    char_type* __intbuf_;
+    size_t __ibs_;
+    streambuf* __bufptr_;
+    _Codecvt* __cv_;
+    state_type __st_;
+    ios_base::openmode __cm_;
+    bool __owns_eb_;
+    bool __owns_ib_;
+    bool __always_noconv_;
+
+    wbuffer_convert(const wbuffer_convert&);
+    wbuffer_convert& operator=(const wbuffer_convert&);
+public:
+    _LIBCPP_EXPLICIT_AFTER_CXX11 wbuffer_convert(streambuf* __bytebuf = 0, 
+            _Codecvt* __pcvt = new _Codecvt, state_type __state = state_type());
+    ~wbuffer_convert();
+
+    _LIBCPP_INLINE_VISIBILITY
+    streambuf* rdbuf() const {return __bufptr_;}
+    _LIBCPP_INLINE_VISIBILITY
+    streambuf* rdbuf(streambuf* __bytebuf)
+    {
+        streambuf* __r = __bufptr_;
+        __bufptr_ = __bytebuf;
+        return __r;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    state_type state() const {return __st_;}
+
+protected:
+    virtual int_type underflow();
+    virtual int_type pbackfail(int_type __c = traits_type::eof());
+    virtual int_type overflow (int_type __c = traits_type::eof());
+    virtual basic_streambuf<char_type, traits_type>* setbuf(char_type* __s,
+                                                            streamsize __n);
+    virtual pos_type seekoff(off_type __off, ios_base::seekdir __way,
+                             ios_base::openmode __wch = ios_base::in | ios_base::out);
+    virtual pos_type seekpos(pos_type __sp,
+                             ios_base::openmode __wch = ios_base::in | ios_base::out);
+    virtual int sync();
+
+private:
+    bool __read_mode();
+    void __write_mode();
+    wbuffer_convert* __close();
+};
+
+template <class _Codecvt, class _Elem, class _Tr>
+wbuffer_convert<_Codecvt, _Elem, _Tr>::
+    wbuffer_convert(streambuf* __bytebuf, _Codecvt* __pcvt, state_type __state)
+    : __extbuf_(0),
+      __extbufnext_(0),
+      __extbufend_(0),
+      __ebs_(0),
+      __intbuf_(0),
+      __ibs_(0),
+      __bufptr_(__bytebuf),
+      __cv_(__pcvt),
+      __st_(__state),
+      __cm_(0),
+      __owns_eb_(false),
+      __owns_ib_(false),
+      __always_noconv_(__cv_ ? __cv_->always_noconv() : false)
+{
+    setbuf(0, 4096);
+}
+
+template <class _Codecvt, class _Elem, class _Tr>
+wbuffer_convert<_Codecvt, _Elem, _Tr>::~wbuffer_convert()
+{
+    __close();
+    delete __cv_;
+    if (__owns_eb_)
+        delete [] __extbuf_;
+    if (__owns_ib_)
+        delete [] __intbuf_;
+}
+
+template <class _Codecvt, class _Elem, class _Tr>
+typename wbuffer_convert<_Codecvt, _Elem, _Tr>::int_type
+wbuffer_convert<_Codecvt, _Elem, _Tr>::underflow()
+{
+    if (__cv_ == 0 || __bufptr_ == 0)
+        return traits_type::eof();
+    bool __initial = __read_mode();
+    char_type __1buf;
+    if (this->gptr() == 0)
+        this->setg(&__1buf, &__1buf+1, &__1buf+1);
+    const size_t __unget_sz = __initial ? 0 : min<size_t>((this->egptr() - this->eback()) / 2, 4);
+    int_type __c = traits_type::eof();
+    if (this->gptr() == this->egptr())
+    {
+        memmove(this->eback(), this->egptr() - __unget_sz, __unget_sz * sizeof(char_type));
+        if (__always_noconv_)
+        {
+            streamsize __nmemb = static_cast<streamsize>(this->egptr() - this->eback() - __unget_sz);
+            __nmemb = __bufptr_->sgetn((char*)this->eback() + __unget_sz, __nmemb);
+            if (__nmemb != 0)
+            {
+                this->setg(this->eback(),
+                           this->eback() + __unget_sz,
+                           this->eback() + __unget_sz + __nmemb);
+                __c = *this->gptr();
+            }
+        }
+        else
+        {
+            memmove(__extbuf_, __extbufnext_, __extbufend_ - __extbufnext_);
+            __extbufnext_ = __extbuf_ + (__extbufend_ - __extbufnext_);
+            __extbufend_ = __extbuf_ + (__extbuf_ == __extbuf_min_ ? sizeof(__extbuf_min_) : __ebs_);
+            streamsize __nmemb = _VSTD::min(static_cast<streamsize>(this->egptr() - this->eback() - __unget_sz),
+                                 static_cast<streamsize>(__extbufend_ - __extbufnext_));
+            codecvt_base::result __r;
+            state_type __svs = __st_;
+            streamsize __nr = __bufptr_->sgetn(const_cast<char*>(__extbufnext_), __nmemb);
+            if (__nr != 0)
+            {
+                __extbufend_ = __extbufnext_ + __nr;
+                char_type*  __inext;
+                __r = __cv_->in(__st_, __extbuf_, __extbufend_, __extbufnext_,
+                                       this->eback() + __unget_sz,
+                                       this->egptr(), __inext);
+                if (__r == codecvt_base::noconv)
+                {
+                    this->setg((char_type*)__extbuf_, (char_type*)__extbuf_, (char_type*)__extbufend_);
+                    __c = *this->gptr();
+                }
+                else if (__inext != this->eback() + __unget_sz)
+                {
+                    this->setg(this->eback(), this->eback() + __unget_sz, __inext);
+                    __c = *this->gptr();
+                }
+            }
+        }
+    }
+    else
+        __c = *this->gptr();
+    if (this->eback() == &__1buf)
+        this->setg(0, 0, 0);
+    return __c;
+}
+
+template <class _Codecvt, class _Elem, class _Tr>
+typename wbuffer_convert<_Codecvt, _Elem, _Tr>::int_type
+wbuffer_convert<_Codecvt, _Elem, _Tr>::pbackfail(int_type __c)
+{
+    if (__cv_ != 0 && __bufptr_ != 0 && this->eback() < this->gptr())
+    {
+        if (traits_type::eq_int_type(__c, traits_type::eof()))
+        {
+            this->gbump(-1);
+            return traits_type::not_eof(__c);
+        }
+        if (traits_type::eq(traits_type::to_char_type(__c), this->gptr()[-1]))
+        {
+            this->gbump(-1);
+            *this->gptr() = traits_type::to_char_type(__c);
+            return __c;
+        }
+    }
+    return traits_type::eof();
+}
+
+template <class _Codecvt, class _Elem, class _Tr>
+typename wbuffer_convert<_Codecvt, _Elem, _Tr>::int_type
+wbuffer_convert<_Codecvt, _Elem, _Tr>::overflow(int_type __c)
+{
+    if (__cv_ == 0 || __bufptr_ == 0)
+        return traits_type::eof();
+    __write_mode();
+    char_type __1buf;
+    char_type* __pb_save = this->pbase();
+    char_type* __epb_save = this->epptr();
+    if (!traits_type::eq_int_type(__c, traits_type::eof()))
+    {
+        if (this->pptr() == 0)
+            this->setp(&__1buf, &__1buf+1);
+        *this->pptr() = traits_type::to_char_type(__c);
+        this->pbump(1);
+    }
+    if (this->pptr() != this->pbase())
+    {
+        if (__always_noconv_)
+        {
+            streamsize __nmemb = static_cast<streamsize>(this->pptr() - this->pbase());
+            if (__bufptr_->sputn((const char*)this->pbase(), __nmemb) != __nmemb)
+                return traits_type::eof();
+        }
+        else
+        {
+            char* __extbe = __extbuf_;
+            codecvt_base::result __r;
+            do
+            {
+                const char_type* __e;
+                __r = __cv_->out(__st_, this->pbase(), this->pptr(), __e,
+                                        __extbuf_, __extbuf_ + __ebs_, __extbe);
+                if (__e == this->pbase())
+                    return traits_type::eof();
+                if (__r == codecvt_base::noconv)
+                {
+                    streamsize __nmemb = static_cast<size_t>(this->pptr() - this->pbase());
+                    if (__bufptr_->sputn((const char*)this->pbase(), __nmemb) != __nmemb)
+                        return traits_type::eof();
+                }
+                else if (__r == codecvt_base::ok || __r == codecvt_base::partial)
+                {
+                    streamsize __nmemb = static_cast<size_t>(__extbe - __extbuf_);
+                    if (__bufptr_->sputn(__extbuf_, __nmemb) != __nmemb)
+                        return traits_type::eof();
+                    if (__r == codecvt_base::partial)
+                    {
+                        this->setp((char_type*)__e, this->pptr());
+                        this->pbump(this->epptr() - this->pbase());
+                    }
+                }
+                else
+                    return traits_type::eof();
+            } while (__r == codecvt_base::partial);
+        }
+        this->setp(__pb_save, __epb_save);
+    }
+    return traits_type::not_eof(__c);
+}
+
+template <class _Codecvt, class _Elem, class _Tr>
+basic_streambuf<_Elem, _Tr>*
+wbuffer_convert<_Codecvt, _Elem, _Tr>::setbuf(char_type* __s, streamsize __n)
+{
+    this->setg(0, 0, 0);
+    this->setp(0, 0);
+    if (__owns_eb_)
+        delete [] __extbuf_;
+    if (__owns_ib_)
+        delete [] __intbuf_;
+    __ebs_ = __n;
+    if (__ebs_ > sizeof(__extbuf_min_))
+    {
+        if (__always_noconv_ && __s)
+        {
+            __extbuf_ = (char*)__s;
+            __owns_eb_ = false;
+        }
+        else
+        {
+            __extbuf_ = new char[__ebs_];
+            __owns_eb_ = true;
+        }
+    }
+    else
+    {
+        __extbuf_ = __extbuf_min_;
+        __ebs_ = sizeof(__extbuf_min_);
+        __owns_eb_ = false;
+    }
+    if (!__always_noconv_)
+    {
+        __ibs_ = max<streamsize>(__n, sizeof(__extbuf_min_));
+        if (__s && __ibs_ >= sizeof(__extbuf_min_))
+        {
+            __intbuf_ = __s;
+            __owns_ib_ = false;
+        }
+        else
+        {
+            __intbuf_ = new char_type[__ibs_];
+            __owns_ib_ = true;
+        }
+    }
+    else
+    {
+        __ibs_ = 0;
+        __intbuf_ = 0;
+        __owns_ib_ = false;
+    }
+    return this;
+}
+
+template <class _Codecvt, class _Elem, class _Tr>
+typename wbuffer_convert<_Codecvt, _Elem, _Tr>::pos_type
+wbuffer_convert<_Codecvt, _Elem, _Tr>::seekoff(off_type __off, ios_base::seekdir __way,
+                                        ios_base::openmode __om)
+{
+    int __width = __cv_->encoding();
+    if (__cv_ == 0 || __bufptr_ == 0 || (__width <= 0 && __off != 0) || sync())
+        return pos_type(off_type(-1));
+    // __width > 0 || __off == 0
+    switch (__way)
+    {
+    case ios_base::beg:
+        break;
+    case ios_base::cur:
+        break;
+    case ios_base::end:
+        break;
+    default:
+        return pos_type(off_type(-1));
+    }
+    pos_type __r = __bufptr_->pubseekoff(__width * __off, __way, __om);
+    __r.state(__st_);
+    return __r;
+}
+
+template <class _Codecvt, class _Elem, class _Tr>
+typename wbuffer_convert<_Codecvt, _Elem, _Tr>::pos_type
+wbuffer_convert<_Codecvt, _Elem, _Tr>::seekpos(pos_type __sp, ios_base::openmode __wch)
+{
+    if (__cv_ == 0 || __bufptr_ == 0 || sync())
+        return pos_type(off_type(-1));
+    if (__bufptr_->pubseekpos(__sp, __wch) == pos_type(off_type(-1)))
+        return pos_type(off_type(-1));
+    return __sp;
+}
+
+template <class _Codecvt, class _Elem, class _Tr>
+int
+wbuffer_convert<_Codecvt, _Elem, _Tr>::sync()
+{
+    if (__cv_ == 0 || __bufptr_ == 0)
+        return 0;
+    if (__cm_ & ios_base::out)
+    {
+        if (this->pptr() != this->pbase())
+            if (overflow() == traits_type::eof())
+                return -1;
+        codecvt_base::result __r;
+        do
+        {
+            char* __extbe;
+            __r = __cv_->unshift(__st_, __extbuf_, __extbuf_ + __ebs_, __extbe);
+            streamsize __nmemb = static_cast<streamsize>(__extbe - __extbuf_);
+            if (__bufptr_->sputn(__extbuf_, __nmemb) != __nmemb)
+                return -1;
+        } while (__r == codecvt_base::partial);
+        if (__r == codecvt_base::error)
+            return -1;
+        if (__bufptr_->pubsync())
+            return -1;
+    }
+    else if (__cm_ & ios_base::in)
+    {
+        off_type __c;
+        if (__always_noconv_)
+            __c = this->egptr() - this->gptr();
+        else
+        {
+            int __width = __cv_->encoding();
+            __c = __extbufend_ - __extbufnext_;
+            if (__width > 0)
+                __c += __width * (this->egptr() - this->gptr());
+            else
+            {
+                if (this->gptr() != this->egptr())
+                {
+                    reverse(this->gptr(), this->egptr());
+                    codecvt_base::result __r;
+                    const char_type* __e = this->gptr();
+                    char* __extbe;
+                    do
+                    {
+                        __r = __cv_->out(__st_, __e, this->egptr(), __e,
+                                         __extbuf_, __extbuf_ + __ebs_, __extbe);
+                        switch (__r)
+                        {
+                        case codecvt_base::noconv:
+                            __c += this->egptr() - this->gptr();
+                            break;
+                        case codecvt_base::ok:
+                        case codecvt_base::partial:
+                            __c += __extbe - __extbuf_;
+                            break;
+                        default:
+                            return -1;
+                        }
+                    } while (__r == codecvt_base::partial);
+                }
+            }
+        }
+        if (__bufptr_->pubseekoff(-__c, ios_base::cur, __cm_) == pos_type(off_type(-1)))
+            return -1;
+        this->setg(0, 0, 0);
+        __cm_ = 0;
+    }
+    return 0;
+}
+
+template <class _Codecvt, class _Elem, class _Tr>
+bool
+wbuffer_convert<_Codecvt, _Elem, _Tr>::__read_mode()
+{
+    if (!(__cm_ & ios_base::in))
+    {
+        this->setp(0, 0);
+        if (__always_noconv_)
+            this->setg((char_type*)__extbuf_,
+                       (char_type*)__extbuf_ + __ebs_,
+                       (char_type*)__extbuf_ + __ebs_);
+        else
+            this->setg(__intbuf_, __intbuf_ + __ibs_, __intbuf_ + __ibs_);
+        __cm_ = ios_base::in;
+        return true;
+    }
+    return false;
+}
+
+template <class _Codecvt, class _Elem, class _Tr>
+void
+wbuffer_convert<_Codecvt, _Elem, _Tr>::__write_mode()
+{
+    if (!(__cm_ & ios_base::out))
+    {
+        this->setg(0, 0, 0);
+        if (__ebs_ > sizeof(__extbuf_min_))
+        {
+            if (__always_noconv_)
+                this->setp((char_type*)__extbuf_,
+                           (char_type*)__extbuf_ + (__ebs_ - 1));
+            else
+                this->setp(__intbuf_, __intbuf_ + (__ibs_ - 1));
+        }
+        else
+            this->setp(0, 0);
+        __cm_ = ios_base::out;
+    }
+}
+
+template <class _Codecvt, class _Elem, class _Tr>
+wbuffer_convert<_Codecvt, _Elem, _Tr>*
+wbuffer_convert<_Codecvt, _Elem, _Tr>::__close()
+{
+    wbuffer_convert* __rt = 0;
+    if (__cv_ != 0 && __bufptr_ != 0)
+    {
+        __rt = this;
+        if ((__cm_ & ios_base::out) && sync())
+            __rt = 0;
+    }
+    return __rt;
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_LOCALE

diff --git a/libcxx/include/map b/libcxx/include/map
new file mode 100644
index 0000000..eb6b8ed
--- /dev/null
+++ b/libcxx/include/map

@@ -0,0 +1,2230 @@
+// -*- C++ -*-
+//===----------------------------- map ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_MAP
+#define _LIBCPP_MAP
+
+/*
+
+    map synopsis
+
+namespace std
+{
+
+template <class Key, class T, class Compare = less<Key>,
+          class Allocator = allocator<pair<const Key, T>>>
+class map
+{
+public:
+    // types:
+    typedef Key                                      key_type;
+    typedef T                                        mapped_type;
+    typedef pair<const key_type, mapped_type>        value_type;
+    typedef Compare                                  key_compare;
+    typedef Allocator                                allocator_type;
+    typedef typename allocator_type::reference       reference;
+    typedef typename allocator_type::const_reference const_reference;
+    typedef typename allocator_type::pointer         pointer;
+    typedef typename allocator_type::const_pointer   const_pointer;
+    typedef typename allocator_type::size_type       size_type;
+    typedef typename allocator_type::difference_type difference_type;
+
+    typedef implementation-defined                   iterator;
+    typedef implementation-defined                   const_iterator;
+    typedef std::reverse_iterator<iterator>          reverse_iterator;
+    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;
+
+    class value_compare
+        : public binary_function<value_type, value_type, bool>
+    {
+        friend class map;
+    protected:
+        key_compare comp;
+
+        value_compare(key_compare c);
+    public:
+        bool operator()(const value_type& x, const value_type& y) const;
+    };
+
+    // construct/copy/destroy:
+    map()
+        noexcept(
+            is_nothrow_default_constructible<allocator_type>::value &&
+            is_nothrow_default_constructible<key_compare>::value &&
+            is_nothrow_copy_constructible<key_compare>::value);
+    explicit map(const key_compare& comp);
+    map(const key_compare& comp, const allocator_type& a);
+    template <class InputIterator>
+        map(InputIterator first, InputIterator last,
+            const key_compare& comp = key_compare());
+    template <class InputIterator>
+        map(InputIterator first, InputIterator last,
+            const key_compare& comp, const allocator_type& a);
+    map(const map& m);
+    map(map&& m)
+        noexcept(
+            is_nothrow_move_constructible<allocator_type>::value &&
+            is_nothrow_move_constructible<key_compare>::value);
+    explicit map(const allocator_type& a);
+    map(const map& m, const allocator_type& a);
+    map(map&& m, const allocator_type& a);
+    map(initializer_list<value_type> il, const key_compare& comp = key_compare());
+    map(initializer_list<value_type> il, const key_compare& comp, const allocator_type& a);
+    template <class InputIterator>
+        map(InputIterator first, InputIterator last, const allocator_type& a)
+            : map(first, last, Compare(), a) {}  // C++14
+    map(initializer_list<value_type> il, const allocator_type& a)
+        : map(il, Compare(), a) {}  // C++14
+   ~map();
+
+    map& operator=(const map& m);
+    map& operator=(map&& m)
+        noexcept(
+            allocator_type::propagate_on_container_move_assignment::value &&
+            is_nothrow_move_assignable<allocator_type>::value &&
+            is_nothrow_move_assignable<key_compare>::value);
+    map& operator=(initializer_list<value_type> il);
+
+    // iterators:
+          iterator begin() noexcept;
+    const_iterator begin() const noexcept;
+          iterator end() noexcept;
+    const_iterator end()   const noexcept;
+
+          reverse_iterator rbegin() noexcept;
+    const_reverse_iterator rbegin() const noexcept;
+          reverse_iterator rend() noexcept;
+    const_reverse_iterator rend()   const noexcept;
+
+    const_iterator         cbegin()  const noexcept;
+    const_iterator         cend()    const noexcept;
+    const_reverse_iterator crbegin() const noexcept;
+    const_reverse_iterator crend()   const noexcept;
+
+    // capacity:
+    bool      empty()    const noexcept;
+    size_type size()     const noexcept;
+    size_type max_size() const noexcept;
+
+    // element access:
+    mapped_type& operator[](const key_type& k);
+    mapped_type& operator[](key_type&& k);
+
+          mapped_type& at(const key_type& k);
+    const mapped_type& at(const key_type& k) const;
+
+    // modifiers:
+    template <class... Args>
+        pair<iterator, bool> emplace(Args&&... args);
+    template <class... Args>
+        iterator emplace_hint(const_iterator position, Args&&... args);
+    pair<iterator, bool> insert(const value_type& v);
+    template <class P>
+        pair<iterator, bool> insert(P&& p);
+    iterator insert(const_iterator position, const value_type& v);
+    template <class P>
+        iterator insert(const_iterator position, P&& p);
+    template <class InputIterator>
+        void insert(InputIterator first, InputIterator last);
+    void insert(initializer_list<value_type> il);
+
+    template <class... Args>
+        pair<iterator, bool> try_emplace(const key_type& k, Args&&... args);          // C++17
+    template <class... Args>
+        pair<iterator, bool> try_emplace(key_type&& k, Args&&... args);               // C++17
+    template <class... Args>
+        iterator try_emplace(const_iterator hint, const key_type& k, Args&&... args); // C++17
+    template <class... Args>
+        iterator try_emplace(const_iterator hint, key_type&& k, Args&&... args);      // C++17
+    template <class M>
+        pair<iterator, bool> insert_or_assign(const key_type& k, M&& obj);            // C++17
+    template <class M>
+        pair<iterator, bool> insert_or_assign(key_type&& k, M&& obj);                 // C++17
+    template <class M>
+        iterator insert_or_assign(const_iterator hint, const key_type& k, M&& obj);   // C++17
+    template <class M>
+        iterator insert_or_assign(const_iterator hint, key_type&& k, M&& obj);        // C++17
+
+    iterator  erase(const_iterator position);
+    iterator  erase(iterator position); // C++14
+    size_type erase(const key_type& k);
+    iterator  erase(const_iterator first, const_iterator last);
+    void clear() noexcept;
+
+    void swap(map& m)
+        noexcept(allocator_traits<allocator_type>::is_always_equal::value &&
+            __is_nothrow_swappable<key_compare>::value); // C++17
+
+    // observers:
+    allocator_type get_allocator() const noexcept;
+    key_compare    key_comp()      const;
+    value_compare  value_comp()    const;
+
+    // map operations:
+          iterator find(const key_type& k);
+    const_iterator find(const key_type& k) const;
+    template<typename K>
+        iterator find(const K& x);              // C++14
+    template<typename K>
+        const_iterator find(const K& x) const;  // C++14
+    template<typename K>
+      size_type count(const K& x) const;        // C++14
+
+    size_type      count(const key_type& k) const;
+          iterator lower_bound(const key_type& k);
+    const_iterator lower_bound(const key_type& k) const;
+    template<typename K>
+        iterator lower_bound(const K& x);              // C++14
+    template<typename K>
+        const_iterator lower_bound(const K& x) const;  // C++14
+
+          iterator upper_bound(const key_type& k);
+    const_iterator upper_bound(const key_type& k) const;
+    template<typename K>
+        iterator upper_bound(const K& x);              // C++14
+    template<typename K>
+        const_iterator upper_bound(const K& x) const;  // C++14
+
+    pair<iterator,iterator>             equal_range(const key_type& k);
+    pair<const_iterator,const_iterator> equal_range(const key_type& k) const;
+    template<typename K>
+        pair<iterator,iterator>             equal_range(const K& x);        // C++14
+    template<typename K>
+        pair<const_iterator,const_iterator> equal_range(const K& x) const;  // C++14
+};
+
+template <class Key, class T, class Compare, class Allocator>
+bool
+operator==(const map<Key, T, Compare, Allocator>& x,
+           const map<Key, T, Compare, Allocator>& y);
+
+template <class Key, class T, class Compare, class Allocator>
+bool
+operator< (const map<Key, T, Compare, Allocator>& x,
+           const map<Key, T, Compare, Allocator>& y);
+
+template <class Key, class T, class Compare, class Allocator>
+bool
+operator!=(const map<Key, T, Compare, Allocator>& x,
+           const map<Key, T, Compare, Allocator>& y);
+
+template <class Key, class T, class Compare, class Allocator>
+bool
+operator> (const map<Key, T, Compare, Allocator>& x,
+           const map<Key, T, Compare, Allocator>& y);
+
+template <class Key, class T, class Compare, class Allocator>
+bool
+operator>=(const map<Key, T, Compare, Allocator>& x,
+           const map<Key, T, Compare, Allocator>& y);
+
+template <class Key, class T, class Compare, class Allocator>
+bool
+operator<=(const map<Key, T, Compare, Allocator>& x,
+           const map<Key, T, Compare, Allocator>& y);
+
+// specialized algorithms:
+template <class Key, class T, class Compare, class Allocator>
+void
+swap(map<Key, T, Compare, Allocator>& x, map<Key, T, Compare, Allocator>& y)
+    noexcept(noexcept(x.swap(y)));
+
+template <class Key, class T, class Compare = less<Key>,
+          class Allocator = allocator<pair<const Key, T>>>
+class multimap
+{
+public:
+    // types:
+    typedef Key                                      key_type;
+    typedef T                                        mapped_type;
+    typedef pair<const key_type,mapped_type>         value_type;
+    typedef Compare                                  key_compare;
+    typedef Allocator                                allocator_type;
+    typedef typename allocator_type::reference       reference;
+    typedef typename allocator_type::const_reference const_reference;
+    typedef typename allocator_type::size_type       size_type;
+    typedef typename allocator_type::difference_type difference_type;
+    typedef typename allocator_type::pointer         pointer;
+    typedef typename allocator_type::const_pointer   const_pointer;
+
+    typedef implementation-defined                   iterator;
+    typedef implementation-defined                   const_iterator;
+    typedef std::reverse_iterator<iterator>          reverse_iterator;
+    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;
+
+    class value_compare
+        : public binary_function<value_type,value_type,bool>
+    {
+        friend class multimap;
+    protected:
+        key_compare comp;
+        value_compare(key_compare c);
+    public:
+        bool operator()(const value_type& x, const value_type& y) const;
+    };
+
+    // construct/copy/destroy:
+    multimap()
+        noexcept(
+            is_nothrow_default_constructible<allocator_type>::value &&
+            is_nothrow_default_constructible<key_compare>::value &&
+            is_nothrow_copy_constructible<key_compare>::value);
+    explicit multimap(const key_compare& comp);
+    multimap(const key_compare& comp, const allocator_type& a);
+    template <class InputIterator>
+        multimap(InputIterator first, InputIterator last, const key_compare& comp);
+    template <class InputIterator>
+        multimap(InputIterator first, InputIterator last, const key_compare& comp,
+                 const allocator_type& a);
+    multimap(const multimap& m);
+    multimap(multimap&& m)
+        noexcept(
+            is_nothrow_move_constructible<allocator_type>::value &&
+            is_nothrow_move_constructible<key_compare>::value);
+    explicit multimap(const allocator_type& a);
+    multimap(const multimap& m, const allocator_type& a);
+    multimap(multimap&& m, const allocator_type& a);
+    multimap(initializer_list<value_type> il, const key_compare& comp = key_compare());
+    multimap(initializer_list<value_type> il, const key_compare& comp,
+             const allocator_type& a);
+    template <class InputIterator>
+        multimap(InputIterator first, InputIterator last, const allocator_type& a)
+            : multimap(first, last, Compare(), a) {} // C++14
+    multimap(initializer_list<value_type> il, const allocator_type& a)
+        : multimap(il, Compare(), a) {} // C++14
+    ~multimap();
+
+    multimap& operator=(const multimap& m);
+    multimap& operator=(multimap&& m)
+        noexcept(
+            allocator_type::propagate_on_container_move_assignment::value &&
+            is_nothrow_move_assignable<allocator_type>::value &&
+            is_nothrow_move_assignable<key_compare>::value);
+    multimap& operator=(initializer_list<value_type> il);
+
+    // iterators:
+          iterator begin() noexcept;
+    const_iterator begin() const noexcept;
+          iterator end() noexcept;
+    const_iterator end()   const noexcept;
+
+          reverse_iterator rbegin() noexcept;
+    const_reverse_iterator rbegin() const noexcept;
+          reverse_iterator rend() noexcept;
+    const_reverse_iterator rend()   const noexcept;
+
+    const_iterator         cbegin()  const noexcept;
+    const_iterator         cend()    const noexcept;
+    const_reverse_iterator crbegin() const noexcept;
+    const_reverse_iterator crend()   const noexcept;
+
+    // capacity:
+    bool      empty()    const noexcept;
+    size_type size()     const noexcept;
+    size_type max_size() const noexcept;
+
+    // modifiers:
+    template <class... Args>
+        iterator emplace(Args&&... args);
+    template <class... Args>
+        iterator emplace_hint(const_iterator position, Args&&... args);
+    iterator insert(const value_type& v);
+    template <class P>
+        iterator insert(P&& p);
+    iterator insert(const_iterator position, const value_type& v);
+    template <class P>
+        iterator insert(const_iterator position, P&& p);
+    template <class InputIterator>
+        void insert(InputIterator first, InputIterator last);
+    void insert(initializer_list<value_type> il);
+
+    iterator  erase(const_iterator position);
+    iterator  erase(iterator position); // C++14
+    size_type erase(const key_type& k);
+    iterator  erase(const_iterator first, const_iterator last);
+    void clear() noexcept;
+
+    void swap(multimap& m)
+        noexcept(allocator_traits<allocator_type>::is_always_equal::value &&
+            __is_nothrow_swappable<key_compare>::value); // C++17
+
+    // observers:
+    allocator_type get_allocator() const noexcept;
+    key_compare    key_comp()      const;
+    value_compare  value_comp()    const;
+
+    // map operations:
+          iterator find(const key_type& k);
+    const_iterator find(const key_type& k) const;
+    template<typename K>
+        iterator find(const K& x);              // C++14
+    template<typename K>
+        const_iterator find(const K& x) const;  // C++14
+    template<typename K>
+      size_type count(const K& x) const;        // C++14
+
+    size_type      count(const key_type& k) const;
+          iterator lower_bound(const key_type& k);
+    const_iterator lower_bound(const key_type& k) const;
+    template<typename K>
+        iterator lower_bound(const K& x);              // C++14
+    template<typename K>
+        const_iterator lower_bound(const K& x) const;  // C++14
+
+          iterator upper_bound(const key_type& k);
+    const_iterator upper_bound(const key_type& k) const;
+    template<typename K>
+        iterator upper_bound(const K& x);              // C++14
+    template<typename K>
+        const_iterator upper_bound(const K& x) const;  // C++14
+
+    pair<iterator,iterator>             equal_range(const key_type& k);
+    pair<const_iterator,const_iterator> equal_range(const key_type& k) const;
+    template<typename K>
+        pair<iterator,iterator>             equal_range(const K& x);        // C++14
+    template<typename K>
+        pair<const_iterator,const_iterator> equal_range(const K& x) const;  // C++14
+};
+
+template <class Key, class T, class Compare, class Allocator>
+bool
+operator==(const multimap<Key, T, Compare, Allocator>& x,
+           const multimap<Key, T, Compare, Allocator>& y);
+
+template <class Key, class T, class Compare, class Allocator>
+bool
+operator< (const multimap<Key, T, Compare, Allocator>& x,
+           const multimap<Key, T, Compare, Allocator>& y);
+
+template <class Key, class T, class Compare, class Allocator>
+bool
+operator!=(const multimap<Key, T, Compare, Allocator>& x,
+           const multimap<Key, T, Compare, Allocator>& y);
+
+template <class Key, class T, class Compare, class Allocator>
+bool
+operator> (const multimap<Key, T, Compare, Allocator>& x,
+           const multimap<Key, T, Compare, Allocator>& y);
+
+template <class Key, class T, class Compare, class Allocator>
+bool
+operator>=(const multimap<Key, T, Compare, Allocator>& x,
+           const multimap<Key, T, Compare, Allocator>& y);
+
+template <class Key, class T, class Compare, class Allocator>
+bool
+operator<=(const multimap<Key, T, Compare, Allocator>& x,
+           const multimap<Key, T, Compare, Allocator>& y);
+
+// specialized algorithms:
+template <class Key, class T, class Compare, class Allocator>
+void
+swap(multimap<Key, T, Compare, Allocator>& x,
+     multimap<Key, T, Compare, Allocator>& y)
+    noexcept(noexcept(x.swap(y)));
+
+}  // std
+
+*/
+
+#include <__config>
+#include <__tree>
+#include <iterator>
+#include <memory>
+#include <utility>
+#include <functional>
+#include <initializer_list>
+#include <type_traits>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Key, class _CP, class _Compare,
+          bool = is_empty<_Compare>::value && !__libcpp_is_final<_Compare>::value
+         >
+class __map_value_compare
+    : private _Compare
+{
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    __map_value_compare()
+        _NOEXCEPT_(is_nothrow_default_constructible<_Compare>::value)
+        : _Compare() {}
+    _LIBCPP_INLINE_VISIBILITY
+    __map_value_compare(_Compare c)
+        _NOEXCEPT_(is_nothrow_copy_constructible<_Compare>::value)
+        : _Compare(c) {}
+    _LIBCPP_INLINE_VISIBILITY
+    const _Compare& key_comp() const _NOEXCEPT {return *this;}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _CP& __x, const _CP& __y) const
+        {return static_cast<const _Compare&>(*this)(__x.__cc.first, __y.__cc.first);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _CP& __x, const _Key& __y) const
+        {return static_cast<const _Compare&>(*this)(__x.__cc.first, __y);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _Key& __x, const _CP& __y) const
+        {return static_cast<const _Compare&>(*this)(__x, __y.__cc.first);}
+    void swap(__map_value_compare&__y)
+        _NOEXCEPT_(__is_nothrow_swappable<_Compare>::value)
+    {
+        using _VSTD::swap;
+        swap(static_cast<const _Compare&>(*this), static_cast<const _Compare&>(__y));
+    }
+
+#if _LIBCPP_STD_VER > 11
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value, bool>::type
+    operator () ( const _K2& __x, const _CP& __y ) const
+        {return static_cast<const _Compare&>(*this) (__x, __y.__cc.first);}
+
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value, bool>::type
+    operator () (const _CP& __x, const _K2& __y) const
+        {return static_cast<const _Compare&>(*this) (__x.__cc.first, __y);}
+#endif
+};
+
+template <class _Key, class _CP, class _Compare>
+class __map_value_compare<_Key, _CP, _Compare, false>
+{
+    _Compare comp;
+
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    __map_value_compare()
+        _NOEXCEPT_(is_nothrow_default_constructible<_Compare>::value)
+        : comp() {}
+    _LIBCPP_INLINE_VISIBILITY
+    __map_value_compare(_Compare c)
+        _NOEXCEPT_(is_nothrow_copy_constructible<_Compare>::value)
+        : comp(c) {}
+    _LIBCPP_INLINE_VISIBILITY
+    const _Compare& key_comp() const _NOEXCEPT {return comp;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _CP& __x, const _CP& __y) const
+        {return comp(__x.__cc.first, __y.__cc.first);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _CP& __x, const _Key& __y) const
+        {return comp(__x.__cc.first, __y);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(const _Key& __x, const _CP& __y) const
+        {return comp(__x, __y.__cc.first);}
+    void swap(__map_value_compare&__y)
+        _NOEXCEPT_(__is_nothrow_swappable<_Compare>::value)
+    {
+        using _VSTD::swap;
+        swap(comp, __y.comp);
+    }
+    
+#if _LIBCPP_STD_VER > 11
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value, bool>::type
+    operator () ( const _K2& __x, const _CP& __y ) const
+        {return comp (__x, __y.__cc.first);}
+
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value, bool>::type
+    operator () (const _CP& __x, const _K2& __y) const
+        {return comp (__x.__cc.first, __y);}
+#endif
+};
+
+template <class _Key, class _CP, class _Compare, bool __b>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(__map_value_compare<_Key, _CP, _Compare, __b>& __x,
+     __map_value_compare<_Key, _CP, _Compare, __b>& __y)
+    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
+{
+    __x.swap(__y);
+}
+
+template <class _Allocator>
+class __map_node_destructor
+{
+    typedef _Allocator                          allocator_type;
+    typedef allocator_traits<allocator_type>    __alloc_traits;
+    typedef typename __alloc_traits::value_type::value_type value_type;
+public:
+    typedef typename __alloc_traits::pointer    pointer;
+private:
+    typedef typename value_type::value_type::first_type     first_type;
+    typedef typename value_type::value_type::second_type    second_type;
+
+    allocator_type& __na_;
+
+    __map_node_destructor& operator=(const __map_node_destructor&);
+
+public:
+    bool __first_constructed;
+    bool __second_constructed;
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __map_node_destructor(allocator_type& __na) _NOEXCEPT
+        : __na_(__na),
+          __first_constructed(false),
+          __second_constructed(false)
+        {}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    __map_node_destructor(__tree_node_destructor<allocator_type>&& __x) _NOEXCEPT
+        : __na_(__x.__na_),
+          __first_constructed(__x.__value_constructed),
+          __second_constructed(__x.__value_constructed)
+        {
+            __x.__value_constructed = false;
+        }
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY
+    void operator()(pointer __p) _NOEXCEPT
+    {
+        if (__second_constructed)
+            __alloc_traits::destroy(__na_, _VSTD::addressof(__p->__value_.__cc.second));
+        if (__first_constructed)
+            __alloc_traits::destroy(__na_, _VSTD::addressof(__p->__value_.__cc.first));
+        if (__p)
+            __alloc_traits::deallocate(__na_, __p, 1);
+    }
+};
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+    class map;
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+    class multimap;
+template <class _TreeIterator> class __map_const_iterator;
+
+#if __cplusplus >= 201103L
+
+template <class _Key, class _Tp>
+union __value_type
+{
+    typedef _Key                                     key_type;
+    typedef _Tp                                      mapped_type;
+    typedef pair<const key_type, mapped_type>        value_type;
+    typedef pair<key_type, mapped_type>              __nc_value_type;
+
+    value_type __cc;
+    __nc_value_type __nc;
+
+    template <class ..._Args>
+    _LIBCPP_INLINE_VISIBILITY
+    __value_type(_Args&& ...__args)
+        : __cc(std::forward<_Args>(__args)...) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __value_type(const __value_type& __v)
+        : __cc(__v.__cc) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __value_type(__value_type& __v)
+        : __cc(__v.__cc) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __value_type(__value_type&& __v)
+        : __nc(std::move(__v.__nc)) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __value_type& operator=(const __value_type& __v)
+        {__nc = __v.__cc; return *this;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __value_type& operator=(__value_type&& __v)
+        {__nc = std::move(__v.__nc); return *this;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    ~__value_type() {__cc.~value_type();}
+};
+
+#else
+
+template <class _Key, class _Tp>
+struct __value_type
+{
+    typedef _Key                                     key_type;
+    typedef _Tp                                      mapped_type;
+    typedef pair<const key_type, mapped_type>        value_type;
+
+    value_type __cc;
+
+    _LIBCPP_INLINE_VISIBILITY
+    __value_type() {}
+
+    template <class _A0>
+    _LIBCPP_INLINE_VISIBILITY
+    __value_type(const _A0& __a0)
+        : __cc(__a0) {}
+
+    template <class _A0, class _A1>
+    _LIBCPP_INLINE_VISIBILITY
+    __value_type(const _A0& __a0, const _A1& __a1)
+        : __cc(__a0, __a1) {}
+};
+
+#endif
+
+template <class _Tp>
+struct __extract_key_value_types;
+
+template <class _Key, class _Tp>
+struct __extract_key_value_types<__value_type<_Key, _Tp> >
+{
+  typedef _Key const __key_type;
+  typedef _Tp        __mapped_type;
+};
+
+template <class _TreeIterator>
+class _LIBCPP_TYPE_VIS_ONLY __map_iterator
+{
+    _TreeIterator __i_;
+
+    typedef typename _TreeIterator::__pointer_traits             __pointer_traits;
+    typedef typename _TreeIterator::value_type __value_type;
+    typedef typename __extract_key_value_types<__value_type>::__key_type    __key_type;
+    typedef typename __extract_key_value_types<__value_type>::__mapped_type __mapped_type;
+public:
+    typedef bidirectional_iterator_tag                           iterator_category;
+    typedef pair<__key_type, __mapped_type>                      value_type;
+    typedef typename _TreeIterator::difference_type              difference_type;
+    typedef value_type&                                          reference;
+    typedef typename __pointer_traits::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<value_type>
+#else
+            rebind<value_type>::other
+#endif
+                                                                 pointer;
+
+    _LIBCPP_INLINE_VISIBILITY
+    __map_iterator() _NOEXCEPT {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __map_iterator(_TreeIterator __i) _NOEXCEPT : __i_(__i) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    reference operator*() const {return __i_->__cc;}
+    _LIBCPP_INLINE_VISIBILITY
+    pointer operator->() const {return pointer_traits<pointer>::pointer_to(__i_->__cc);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __map_iterator& operator++() {++__i_; return *this;}
+    _LIBCPP_INLINE_VISIBILITY
+    __map_iterator operator++(int)
+    {
+        __map_iterator __t(*this);
+        ++(*this);
+        return __t;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __map_iterator& operator--() {--__i_; return *this;}
+    _LIBCPP_INLINE_VISIBILITY
+    __map_iterator operator--(int)
+    {
+        __map_iterator __t(*this);
+        --(*this);
+        return __t;
+    }
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator==(const __map_iterator& __x, const __map_iterator& __y)
+        {return __x.__i_ == __y.__i_;}
+    friend 
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(const __map_iterator& __x, const __map_iterator& __y)
+        {return __x.__i_ != __y.__i_;}
+
+    template <class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY map;
+    template <class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY multimap;
+    template <class> friend class _LIBCPP_TYPE_VIS_ONLY __map_const_iterator;
+};
+
+template <class _TreeIterator>
+class _LIBCPP_TYPE_VIS_ONLY __map_const_iterator
+{
+    _TreeIterator __i_;
+
+    typedef typename _TreeIterator::__pointer_traits             __pointer_traits;
+    typedef typename _TreeIterator::value_type __value_type;
+    typedef typename __extract_key_value_types<__value_type>::__key_type    __key_type;
+    typedef typename __extract_key_value_types<__value_type>::__mapped_type __mapped_type;
+public:
+    typedef bidirectional_iterator_tag                           iterator_category;
+    typedef pair<__key_type, __mapped_type>                      value_type;
+    typedef typename _TreeIterator::difference_type              difference_type;
+    typedef const value_type&                                    reference;
+    typedef typename __pointer_traits::template
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+            rebind<const value_type>
+#else
+            rebind<const value_type>::other
+#endif
+                                                                 pointer;
+
+    _LIBCPP_INLINE_VISIBILITY
+    __map_const_iterator() _NOEXCEPT {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __map_const_iterator(_TreeIterator __i) _NOEXCEPT : __i_(__i) {}
+    _LIBCPP_INLINE_VISIBILITY
+    __map_const_iterator(__map_iterator<
+        typename _TreeIterator::__non_const_iterator> __i) _NOEXCEPT
+        : __i_(__i.__i_) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    reference operator*() const {return __i_->__cc;}
+    _LIBCPP_INLINE_VISIBILITY
+    pointer operator->() const {return pointer_traits<pointer>::pointer_to(__i_->__cc);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __map_const_iterator& operator++() {++__i_; return *this;}
+    _LIBCPP_INLINE_VISIBILITY
+    __map_const_iterator operator++(int)
+    {
+        __map_const_iterator __t(*this);
+        ++(*this);
+        return __t;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __map_const_iterator& operator--() {--__i_; return *this;}
+    _LIBCPP_INLINE_VISIBILITY
+    __map_const_iterator operator--(int)
+    {
+        __map_const_iterator __t(*this);
+        --(*this);
+        return __t;
+    }
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator==(const __map_const_iterator& __x, const __map_const_iterator& __y)
+        {return __x.__i_ == __y.__i_;}
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(const __map_const_iterator& __x, const __map_const_iterator& __y)
+        {return __x.__i_ != __y.__i_;}
+
+    template <class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY map;
+    template <class, class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY multimap;
+    template <class, class, class> friend class _LIBCPP_TYPE_VIS_ONLY __tree_const_iterator;
+};
+
+template <class _Key, class _Tp, class _Compare = less<_Key>,
+          class _Allocator = allocator<pair<const _Key, _Tp> > >
+class _LIBCPP_TYPE_VIS_ONLY map
+{
+public:
+    // types:
+    typedef _Key                                     key_type;
+    typedef _Tp                                      mapped_type;
+    typedef pair<const key_type, mapped_type>        value_type;
+    typedef pair<key_type, mapped_type>              __nc_value_type;
+    typedef _Compare                                 key_compare;
+    typedef _Allocator                               allocator_type;
+    typedef value_type&                              reference;
+    typedef const value_type&                        const_reference;
+
+    class _LIBCPP_TYPE_VIS_ONLY value_compare
+        : public binary_function<value_type, value_type, bool>
+    {
+        friend class map;
+    protected:
+        key_compare comp;
+
+        _LIBCPP_INLINE_VISIBILITY value_compare(key_compare c) : comp(c) {}
+    public:
+        _LIBCPP_INLINE_VISIBILITY
+        bool operator()(const value_type& __x, const value_type& __y) const
+            {return comp(__x.first, __y.first);}
+    };
+
+private:
+
+    typedef _VSTD::__value_type<key_type, mapped_type>             __value_type;
+    typedef __map_value_compare<key_type, __value_type, key_compare> __vc;
+    typedef typename __rebind_alloc_helper<allocator_traits<allocator_type>,
+                                                 __value_type>::type __allocator_type;
+    typedef __tree<__value_type, __vc, __allocator_type>   __base;
+    typedef typename __base::__node_traits                 __node_traits;
+    typedef allocator_traits<allocator_type>               __alloc_traits;
+
+    __base __tree_;
+
+public:
+    typedef typename __alloc_traits::pointer               pointer;
+    typedef typename __alloc_traits::const_pointer         const_pointer;
+    typedef typename __alloc_traits::size_type             size_type;
+    typedef typename __alloc_traits::difference_type       difference_type;
+    typedef __map_iterator<typename __base::iterator>             iterator;
+    typedef __map_const_iterator<typename __base::const_iterator> const_iterator;
+    typedef _VSTD::reverse_iterator<iterator>               reverse_iterator;
+    typedef _VSTD::reverse_iterator<const_iterator>         const_reverse_iterator;
+
+    _LIBCPP_INLINE_VISIBILITY
+    map()
+        _NOEXCEPT_(
+            is_nothrow_default_constructible<allocator_type>::value &&
+            is_nothrow_default_constructible<key_compare>::value &&
+            is_nothrow_copy_constructible<key_compare>::value)
+        : __tree_(__vc(key_compare())) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit map(const key_compare& __comp)
+        _NOEXCEPT_(
+            is_nothrow_default_constructible<allocator_type>::value &&
+            is_nothrow_copy_constructible<key_compare>::value)
+        : __tree_(__vc(__comp)) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit map(const key_compare& __comp, const allocator_type& __a)
+        : __tree_(__vc(__comp), __a) {}
+
+    template <class _InputIterator>
+    _LIBCPP_INLINE_VISIBILITY
+        map(_InputIterator __f, _InputIterator __l,
+            const key_compare& __comp = key_compare())
+        : __tree_(__vc(__comp))
+        {
+            insert(__f, __l);
+        }
+
+    template <class _InputIterator>
+    _LIBCPP_INLINE_VISIBILITY
+        map(_InputIterator __f, _InputIterator __l,
+            const key_compare& __comp, const allocator_type& __a)
+        : __tree_(__vc(__comp), __a)
+        {
+            insert(__f, __l);
+        }
+
+#if _LIBCPP_STD_VER > 11
+    template <class _InputIterator>
+    _LIBCPP_INLINE_VISIBILITY 
+    map(_InputIterator __f, _InputIterator __l, const allocator_type& __a)
+        : map(__f, __l, key_compare(), __a) {}
+#endif
+
+    _LIBCPP_INLINE_VISIBILITY
+    map(const map& __m)
+        : __tree_(__m.__tree_)
+        {
+            insert(__m.begin(), __m.end());
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    map& operator=(const map& __m)
+        {
+#if __cplusplus >= 201103L
+            __tree_ = __m.__tree_;
+#else
+            if (this != &__m) {
+                __tree_.clear();
+                __tree_.value_comp() = __m.__tree_.value_comp();
+                __tree_.__copy_assign_alloc(__m.__tree_);
+                insert(__m.begin(), __m.end());
+            }
+#endif
+            return *this;
+        }
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY
+    map(map&& __m)
+        _NOEXCEPT_(is_nothrow_move_constructible<__base>::value)
+        : __tree_(_VSTD::move(__m.__tree_))
+        {
+        }
+
+    map(map&& __m, const allocator_type& __a);
+
+    _LIBCPP_INLINE_VISIBILITY
+    map& operator=(map&& __m)
+        _NOEXCEPT_(is_nothrow_move_assignable<__base>::value)
+        {
+            __tree_ = _VSTD::move(__m.__tree_);
+            return *this;
+        }
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+    _LIBCPP_INLINE_VISIBILITY
+    map(initializer_list<value_type> __il, const key_compare& __comp = key_compare())
+        : __tree_(__vc(__comp))
+        {
+            insert(__il.begin(), __il.end());
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    map(initializer_list<value_type> __il, const key_compare& __comp, const allocator_type& __a)
+        : __tree_(__vc(__comp), __a)
+        {
+            insert(__il.begin(), __il.end());
+        }
+
+#if _LIBCPP_STD_VER > 11
+    _LIBCPP_INLINE_VISIBILITY 
+    map(initializer_list<value_type> __il, const allocator_type& __a)
+        : map(__il, key_compare(), __a) {}
+#endif
+
+    _LIBCPP_INLINE_VISIBILITY
+    map& operator=(initializer_list<value_type> __il)
+        {
+            __tree_.__assign_unique(__il.begin(), __il.end());
+            return *this;
+        }
+
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit map(const allocator_type& __a)
+        : __tree_(__a)
+        {
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    map(const map& __m, const allocator_type& __a)
+        : __tree_(__m.__tree_.value_comp(), __a)
+        {
+            insert(__m.begin(), __m.end());
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+          iterator begin() _NOEXCEPT {return __tree_.begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator begin() const _NOEXCEPT {return __tree_.begin();}
+    _LIBCPP_INLINE_VISIBILITY
+          iterator end() _NOEXCEPT {return __tree_.end();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator end() const _NOEXCEPT {return __tree_.end();}
+
+    _LIBCPP_INLINE_VISIBILITY
+          reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator rbegin() const _NOEXCEPT
+        {return const_reverse_iterator(end());}
+    _LIBCPP_INLINE_VISIBILITY
+          reverse_iterator rend() _NOEXCEPT
+            {return       reverse_iterator(begin());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator rend() const _NOEXCEPT
+        {return const_reverse_iterator(begin());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator cbegin() const _NOEXCEPT {return begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator cend() const _NOEXCEPT {return end();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool      empty() const _NOEXCEPT {return __tree_.size() == 0;}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type size() const _NOEXCEPT {return __tree_.size();}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type max_size() const _NOEXCEPT {return __tree_.max_size();}
+
+    mapped_type& operator[](const key_type& __k);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    mapped_type& operator[](key_type&& __k);
+#endif
+
+          mapped_type& at(const key_type& __k);
+    const mapped_type& at(const key_type& __k) const;
+
+    _LIBCPP_INLINE_VISIBILITY
+    allocator_type get_allocator() const _NOEXCEPT {return __tree_.__alloc();}
+    _LIBCPP_INLINE_VISIBILITY
+    key_compare    key_comp()      const {return __tree_.value_comp().key_comp();}
+    _LIBCPP_INLINE_VISIBILITY
+    value_compare  value_comp()    const {return value_compare(__tree_.value_comp().key_comp());}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+    template <class ..._Args>
+        pair<iterator, bool>
+        emplace(_Args&& ...__args);
+
+    template <class ..._Args>
+        iterator
+        emplace_hint(const_iterator __p, _Args&& ...__args);
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+    template <class _Pp,
+              class = typename enable_if<is_constructible<value_type, _Pp>::value>::type>
+        _LIBCPP_INLINE_VISIBILITY
+        pair<iterator, bool> insert(_Pp&& __p)
+            {return __tree_.__insert_unique(_VSTD::forward<_Pp>(__p));}
+
+    template <class _Pp,
+              class = typename enable_if<is_constructible<value_type, _Pp>::value>::type>
+        _LIBCPP_INLINE_VISIBILITY
+        iterator insert(const_iterator __pos, _Pp&& __p)
+            {return __tree_.__insert_unique(__pos.__i_, _VSTD::forward<_Pp>(__p));}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY
+    pair<iterator, bool>
+        insert(const value_type& __v) {return __tree_.__insert_unique(__v);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator
+        insert(const_iterator __p, const value_type& __v)
+            {return __tree_.__insert_unique(__p.__i_, __v);}
+
+    template <class _InputIterator>
+        _LIBCPP_INLINE_VISIBILITY
+        void insert(_InputIterator __f, _InputIterator __l)
+        {
+            for (const_iterator __e = cend(); __f != __l; ++__f)
+                insert(__e.__i_, *__f);
+        }
+
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+    _LIBCPP_INLINE_VISIBILITY
+    void insert(initializer_list<value_type> __il)
+        {insert(__il.begin(), __il.end());}
+
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+#if _LIBCPP_STD_VER > 14
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    template <class... _Args>
+        _LIBCPP_INLINE_VISIBILITY
+        pair<iterator, bool> try_emplace(const key_type& __k, _Args&&... __args)
+    {
+        iterator __p = lower_bound(__k);
+        if ( __p != end() && !key_comp()(__k, __p->first))
+            return _VSTD::make_pair(__p, false);
+        else
+            return _VSTD::make_pair(
+                      emplace_hint(__p, 
+                        _VSTD::piecewise_construct, _VSTD::forward_as_tuple(__k), 
+                        _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)),
+                      true);
+    }
+
+    template <class... _Args>
+        _LIBCPP_INLINE_VISIBILITY
+        pair<iterator, bool> try_emplace(key_type&& __k, _Args&&... __args)
+    {
+        iterator __p = lower_bound(__k);
+        if ( __p != end() && !key_comp()(__k, __p->first))
+            return _VSTD::make_pair(__p, false);
+        else
+            return _VSTD::make_pair(
+                      emplace_hint(__p, 
+                        _VSTD::piecewise_construct, _VSTD::forward_as_tuple(_VSTD::move(__k)), 
+                        _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)),
+                      true);
+    }
+
+    template <class... _Args>
+        _LIBCPP_INLINE_VISIBILITY
+        iterator try_emplace(const_iterator __h, const key_type& __k, _Args&&... __args)
+    {
+        iterator __p = lower_bound(__k);
+        if ( __p != end() && !key_comp()(__k, __p->first))
+            return __p;
+        else
+            return emplace_hint(__p, 
+                      _VSTD::piecewise_construct, _VSTD::forward_as_tuple(__k), 
+                      _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...));
+    }
+
+    template <class... _Args>
+        _LIBCPP_INLINE_VISIBILITY
+        iterator try_emplace(const_iterator __h, key_type&& __k, _Args&&... __args)
+    {
+        iterator __p = lower_bound(__k);
+        if ( __p != end() && !key_comp()(__k, __p->first))
+            return __p;
+        else
+            return emplace_hint(__p, 
+                      _VSTD::piecewise_construct, _VSTD::forward_as_tuple(_VSTD::move(__k)), 
+                      _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...));
+    }
+
+    template <class _Vp>
+        _LIBCPP_INLINE_VISIBILITY
+        pair<iterator, bool> insert_or_assign(const key_type& __k, _Vp&& __v)
+    {
+        iterator __p = lower_bound(__k);
+        if ( __p != end() && !key_comp()(__k, __p->first))
+        {
+            __p->second = _VSTD::forward<_Vp>(__v);
+            return _VSTD::make_pair(__p, false);
+        }
+        return _VSTD::make_pair(emplace_hint(__p, __k, _VSTD::forward<_Vp>(__v)), true);
+    }
+        
+    template <class _Vp>
+        _LIBCPP_INLINE_VISIBILITY
+        pair<iterator, bool> insert_or_assign(key_type&& __k, _Vp&& __v)
+    {
+        iterator __p = lower_bound(__k);
+        if ( __p != end() && !key_comp()(__k, __p->first))
+        {
+            __p->second = _VSTD::forward<_Vp>(__v);
+            return _VSTD::make_pair(__p, false);
+        }
+        return _VSTD::make_pair(emplace_hint(__p, _VSTD::move(__k), _VSTD::forward<_Vp>(__v)), true);
+    }
+
+    template <class _Vp>
+        _LIBCPP_INLINE_VISIBILITY
+        iterator insert_or_assign(const_iterator __h, const key_type& __k, _Vp&& __v)
+     {
+        iterator __p = lower_bound(__k);
+        if ( __p != end() && !key_comp()(__k, __p->first))
+        {
+            __p->second = _VSTD::forward<_Vp>(__v);
+            return __p;
+        }
+        return emplace_hint(__h, __k, _VSTD::forward<_Vp>(__v));
+     }
+
+    template <class _Vp>
+        _LIBCPP_INLINE_VISIBILITY
+        iterator insert_or_assign(const_iterator __h, key_type&& __k, _Vp&& __v)
+     {
+        iterator __p = lower_bound(__k);
+        if ( __p != end() && !key_comp()(__k, __p->first))
+        {
+            __p->second = _VSTD::forward<_Vp>(__v);
+            return __p;
+        }
+        return emplace_hint(__h, _VSTD::move(__k), _VSTD::forward<_Vp>(__v));
+     }
+#endif
+#endif
+#endif
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator erase(const_iterator __p) {return __tree_.erase(__p.__i_);}
+    _LIBCPP_INLINE_VISIBILITY
+    iterator erase(iterator __p)       {return __tree_.erase(__p.__i_);}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type erase(const key_type& __k)
+        {return __tree_.__erase_unique(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    iterator  erase(const_iterator __f, const_iterator __l)
+        {return __tree_.erase(__f.__i_, __l.__i_);}
+    _LIBCPP_INLINE_VISIBILITY
+    void clear() _NOEXCEPT {__tree_.clear();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(map& __m)
+        _NOEXCEPT_(__is_nothrow_swappable<__base>::value)
+        {__tree_.swap(__m.__tree_);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator find(const key_type& __k)             {return __tree_.find(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator find(const key_type& __k) const {return __tree_.find(__k);}
+#if _LIBCPP_STD_VER > 11
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
+    find(const _K2& __k)                           {return __tree_.find(__k);}
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
+    find(const _K2& __k) const                     {return __tree_.find(__k);}
+#endif
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type      count(const key_type& __k) const
+        {return __tree_.__count_unique(__k);}
+#if _LIBCPP_STD_VER > 11
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,size_type>::type
+    count(const _K2& __k) const {return __tree_.__count_unique(__k);}
+#endif
+    _LIBCPP_INLINE_VISIBILITY
+    iterator lower_bound(const key_type& __k)
+        {return __tree_.lower_bound(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator lower_bound(const key_type& __k) const
+        {return __tree_.lower_bound(__k);}
+#if _LIBCPP_STD_VER > 11
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
+    lower_bound(const _K2& __k)       {return __tree_.lower_bound(__k);}
+
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
+    lower_bound(const _K2& __k) const {return __tree_.lower_bound(__k);}
+#endif
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator upper_bound(const key_type& __k)
+        {return __tree_.upper_bound(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator upper_bound(const key_type& __k) const
+        {return __tree_.upper_bound(__k);}
+#if _LIBCPP_STD_VER > 11
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
+    upper_bound(const _K2& __k)       {return __tree_.upper_bound(__k);}
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
+    upper_bound(const _K2& __k) const {return __tree_.upper_bound(__k);}
+#endif
+
+    _LIBCPP_INLINE_VISIBILITY
+    pair<iterator,iterator> equal_range(const key_type& __k)
+        {return __tree_.__equal_range_unique(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    pair<const_iterator,const_iterator> equal_range(const key_type& __k) const
+        {return __tree_.__equal_range_unique(__k);}
+#if _LIBCPP_STD_VER > 11
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,pair<iterator,iterator>>::type
+    equal_range(const _K2& __k)       {return __tree_.__equal_range_unique(__k);}
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,pair<const_iterator,const_iterator>>::type
+    equal_range(const _K2& __k) const {return __tree_.__equal_range_unique(__k);}
+#endif
+
+private:
+    typedef typename __base::__node                    __node;
+    typedef typename __base::__node_allocator          __node_allocator;
+    typedef typename __base::__node_pointer            __node_pointer;
+    typedef typename __base::__node_const_pointer      __node_const_pointer;
+    typedef typename __base::__node_base_pointer       __node_base_pointer;
+    typedef typename __base::__node_base_const_pointer __node_base_const_pointer;
+    typedef __map_node_destructor<__node_allocator> _Dp;
+    typedef unique_ptr<__node, _Dp> __node_holder;
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    __node_holder __construct_node();
+    template <class _A0>
+        __node_holder __construct_node(_A0&& __a0);
+    __node_holder __construct_node_with_key(key_type&& __k);
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    template <class _A0, class _A1, class ..._Args>
+        __node_holder __construct_node(_A0&& __a0, _A1&& __a1, _Args&& ...__args);
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+#endif
+    __node_holder __construct_node_with_key(const key_type& __k);
+
+    __node_base_pointer&
+        __find_equal_key(__node_base_pointer& __parent, const key_type& __k);
+    __node_base_const_pointer
+        __find_equal_key(__node_base_const_pointer& __parent, const key_type& __k) const;
+};
+
+// Find place to insert if __k doesn't exist
+// Set __parent to parent of null leaf
+// Return reference to null leaf
+// If __k exists, set parent to node of __k and return reference to node of __k
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+typename map<_Key, _Tp, _Compare, _Allocator>::__node_base_pointer&
+map<_Key, _Tp, _Compare, _Allocator>::__find_equal_key(__node_base_pointer& __parent,
+                                                       const key_type& __k)
+{
+    __node_pointer __nd = __tree_.__root();
+    if (__nd != nullptr)
+    {
+        while (true)
+        {
+            if (__tree_.value_comp().key_comp()(__k, __nd->__value_.__cc.first))
+            {
+                if (__nd->__left_ != nullptr)
+                    __nd = static_cast<__node_pointer>(__nd->__left_);
+                else
+                {
+                    __parent = static_cast<__node_base_pointer>(__nd);
+                    return __parent->__left_;
+                }
+            }
+            else if (__tree_.value_comp().key_comp()(__nd->__value_.__cc.first, __k))
+            {
+                if (__nd->__right_ != nullptr)
+                    __nd = static_cast<__node_pointer>(__nd->__right_);
+                else
+                {
+                    __parent = static_cast<__node_base_pointer>(__nd);
+                    return __parent->__right_;
+                }
+            }
+            else
+            {
+                __parent = static_cast<__node_base_pointer>(__nd);
+                return __parent;
+            }
+        }
+    }
+    __parent = static_cast<__node_base_pointer>(__tree_.__end_node());
+    return __parent->__left_;
+}
+
+// Find __k
+// Set __parent to parent of null leaf and
+//    return reference to null leaf iv __k does not exist.
+// If __k exists, set parent to node of __k and return reference to node of __k
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+typename map<_Key, _Tp, _Compare, _Allocator>::__node_base_const_pointer
+map<_Key, _Tp, _Compare, _Allocator>::__find_equal_key(__node_base_const_pointer& __parent,
+                                                       const key_type& __k) const
+{
+    __node_const_pointer __nd = __tree_.__root();
+    if (__nd != nullptr)
+    {
+        while (true)
+        {
+            if (__tree_.value_comp().key_comp()(__k, __nd->__value_.__cc.first))
+            {
+                if (__nd->__left_ != nullptr)
+                    __nd = static_cast<__node_pointer>(__nd->__left_);
+                else
+                {
+                    __parent = static_cast<__node_base_pointer>(__nd);
+                    return const_cast<const __node_base_const_pointer&>(__parent->__left_);
+                }
+            }
+            else if (__tree_.value_comp().key_comp()(__nd->__value_.__cc.first, __k))
+            {
+                if (__nd->__right_ != nullptr)
+                    __nd = static_cast<__node_pointer>(__nd->__right_);
+                else
+                {
+                    __parent = static_cast<__node_base_pointer>(__nd);
+                    return const_cast<const __node_base_const_pointer&>(__parent->__right_);
+                }
+            }
+            else
+            {
+                __parent = static_cast<__node_base_pointer>(__nd);
+                return __parent;
+            }
+        }
+    }
+    __parent = static_cast<__node_base_pointer>(__tree_.__end_node());
+    return const_cast<const __node_base_const_pointer&>(__parent->__left_);
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+map<_Key, _Tp, _Compare, _Allocator>::map(map&& __m, const allocator_type& __a)
+    : __tree_(_VSTD::move(__m.__tree_), __a)
+{
+    if (__a != __m.get_allocator())
+    {
+        const_iterator __e = cend();
+        while (!__m.empty())
+            __tree_.__insert_unique(__e.__i_,
+                    _VSTD::move(__m.__tree_.remove(__m.begin().__i_)->__value_));
+    }
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+typename map<_Key, _Tp, _Compare, _Allocator>::__node_holder
+map<_Key, _Tp, _Compare, _Allocator>::__construct_node()
+{
+    __node_allocator& __na = __tree_.__node_alloc();
+    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_.__cc.first));
+    __h.get_deleter().__first_constructed = true;
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_.__cc.second));
+    __h.get_deleter().__second_constructed = true;
+    return __h;
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+template <class _A0>
+typename map<_Key, _Tp, _Compare, _Allocator>::__node_holder
+map<_Key, _Tp, _Compare, _Allocator>::__construct_node(_A0&& __a0)
+{
+    __node_allocator& __na = __tree_.__node_alloc();
+    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_), _VSTD::forward<_A0>(__a0));
+    __h.get_deleter().__first_constructed = true;
+    __h.get_deleter().__second_constructed = true;
+    return __h;
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+typename map<_Key, _Tp, _Compare, _Allocator>::__node_holder
+map<_Key, _Tp, _Compare, _Allocator>::__construct_node_with_key(key_type&& __k)
+{
+    __node_allocator& __na = __tree_.__node_alloc();
+    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_.__cc.first), _VSTD::move(__k));
+    __h.get_deleter().__first_constructed = true;
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_.__cc.second));
+    __h.get_deleter().__second_constructed = true;
+    return __h;
+}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+template <class _A0, class _A1, class ..._Args>
+typename map<_Key, _Tp, _Compare, _Allocator>::__node_holder
+map<_Key, _Tp, _Compare, _Allocator>::__construct_node(_A0&& __a0, _A1&& __a1, _Args&& ...__args)
+{
+    __node_allocator& __na = __tree_.__node_alloc();
+    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_),
+                             _VSTD::forward<_A0>(__a0), _VSTD::forward<_A1>(__a1),
+                             _VSTD::forward<_Args>(__args)...);
+    __h.get_deleter().__first_constructed = true;
+    __h.get_deleter().__second_constructed = true;
+    return __h;
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+typename map<_Key, _Tp, _Compare, _Allocator>::__node_holder
+map<_Key, _Tp, _Compare, _Allocator>::__construct_node_with_key(const key_type& __k)
+{
+    __node_allocator& __na = __tree_.__node_alloc();
+    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_.__cc.first), __k);
+    __h.get_deleter().__first_constructed = true;
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_.__cc.second));
+    __h.get_deleter().__second_constructed = true;
+    return _VSTD::move(__h);  // explicitly moved for C++03
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+_Tp&
+map<_Key, _Tp, _Compare, _Allocator>::operator[](const key_type& __k)
+{
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_equal_key(__parent, __k);
+    __node_pointer __r = static_cast<__node_pointer>(__child);
+    if (__child == nullptr)
+    {
+        __node_holder __h = __construct_node_with_key(__k);
+        __tree_.__insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
+        __r = __h.release();
+    }
+    return __r->__value_.__cc.second;
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+_Tp&
+map<_Key, _Tp, _Compare, _Allocator>::operator[](key_type&& __k)
+{
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_equal_key(__parent, __k);
+    __node_pointer __r = static_cast<__node_pointer>(__child);
+    if (__child == nullptr)
+    {
+        __node_holder __h = __construct_node_with_key(_VSTD::move(__k));
+        __tree_.__insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
+        __r = __h.release();
+    }
+    return __r->__value_.__cc.second;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+_Tp&
+map<_Key, _Tp, _Compare, _Allocator>::at(const key_type& __k)
+{
+    __node_base_pointer __parent;
+    __node_base_pointer& __child = __find_equal_key(__parent, __k);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__child == nullptr)
+        throw out_of_range("map::at:  key not found");
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return static_cast<__node_pointer>(__child)->__value_.__cc.second;
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+const _Tp&
+map<_Key, _Tp, _Compare, _Allocator>::at(const key_type& __k) const
+{
+    __node_base_const_pointer __parent;
+    __node_base_const_pointer __child = __find_equal_key(__parent, __k);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    if (__child == nullptr)
+        throw out_of_range("map::at:  key not found");
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return static_cast<__node_const_pointer>(__child)->__value_.__cc.second;
+}
+
+#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+template <class ..._Args>
+pair<typename map<_Key, _Tp, _Compare, _Allocator>::iterator, bool>
+map<_Key, _Tp, _Compare, _Allocator>::emplace(_Args&& ...__args)
+{
+    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
+    pair<iterator, bool> __r = __tree_.__node_insert_unique(__h.get());
+    if (__r.second)
+        __h.release();
+    return __r;
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+template <class ..._Args>
+typename map<_Key, _Tp, _Compare, _Allocator>::iterator
+map<_Key, _Tp, _Compare, _Allocator>::emplace_hint(const_iterator __p,
+                                                   _Args&& ...__args)
+{
+    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
+    iterator __r = __tree_.__node_insert_unique(__p.__i_, __h.get());
+    if (__r.__i_.__ptr_ == __h.get())
+        __h.release();
+    return __r;
+}
+
+#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const map<_Key, _Tp, _Compare, _Allocator>& __x,
+           const map<_Key, _Tp, _Compare, _Allocator>& __y)
+{
+    return __x.size() == __y.size() && _VSTD::equal(__x.begin(), __x.end(), __y.begin());
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator< (const map<_Key, _Tp, _Compare, _Allocator>& __x,
+           const map<_Key, _Tp, _Compare, _Allocator>& __y)
+{
+    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const map<_Key, _Tp, _Compare, _Allocator>& __x,
+           const map<_Key, _Tp, _Compare, _Allocator>& __y)
+{
+    return !(__x == __y);
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator> (const map<_Key, _Tp, _Compare, _Allocator>& __x,
+           const map<_Key, _Tp, _Compare, _Allocator>& __y)
+{
+    return __y < __x;
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const map<_Key, _Tp, _Compare, _Allocator>& __x,
+           const map<_Key, _Tp, _Compare, _Allocator>& __y)
+{
+    return !(__x < __y);
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const map<_Key, _Tp, _Compare, _Allocator>& __x,
+           const map<_Key, _Tp, _Compare, _Allocator>& __y)
+{
+    return !(__y < __x);
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(map<_Key, _Tp, _Compare, _Allocator>& __x,
+     map<_Key, _Tp, _Compare, _Allocator>& __y)
+    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
+{
+    __x.swap(__y);
+}
+
+template <class _Key, class _Tp, class _Compare = less<_Key>,
+          class _Allocator = allocator<pair<const _Key, _Tp> > >
+class _LIBCPP_TYPE_VIS_ONLY multimap
+{
+public:
+    // types:
+    typedef _Key                                     key_type;
+    typedef _Tp                                      mapped_type;
+    typedef pair<const key_type, mapped_type>        value_type;
+    typedef pair<key_type, mapped_type>              __nc_value_type;
+    typedef _Compare                                 key_compare;
+    typedef _Allocator                               allocator_type;
+    typedef value_type&                              reference;
+    typedef const value_type&                        const_reference;
+
+    class _LIBCPP_TYPE_VIS_ONLY value_compare
+        : public binary_function<value_type, value_type, bool>
+    {
+        friend class multimap;
+    protected:
+        key_compare comp;
+
+        _LIBCPP_INLINE_VISIBILITY
+        value_compare(key_compare c) : comp(c) {}
+    public:
+        _LIBCPP_INLINE_VISIBILITY
+        bool operator()(const value_type& __x, const value_type& __y) const
+            {return comp(__x.first, __y.first);}
+    };
+
+private:
+
+    typedef _VSTD::__value_type<key_type, mapped_type>             __value_type;
+    typedef __map_value_compare<key_type, __value_type, key_compare> __vc;
+    typedef typename __rebind_alloc_helper<allocator_traits<allocator_type>,
+                                                 __value_type>::type __allocator_type;
+    typedef __tree<__value_type, __vc, __allocator_type>            __base;
+    typedef typename __base::__node_traits                          __node_traits;
+    typedef allocator_traits<allocator_type>                        __alloc_traits;
+
+    __base __tree_;
+
+public:
+    typedef typename __alloc_traits::pointer               pointer;
+    typedef typename __alloc_traits::const_pointer         const_pointer;
+    typedef typename __alloc_traits::size_type             size_type;
+    typedef typename __alloc_traits::difference_type       difference_type;
+    typedef __map_iterator<typename __base::iterator>      iterator;
+    typedef __map_const_iterator<typename __base::const_iterator> const_iterator;
+    typedef _VSTD::reverse_iterator<iterator>               reverse_iterator;
+    typedef _VSTD::reverse_iterator<const_iterator>         const_reverse_iterator;
+
+    _LIBCPP_INLINE_VISIBILITY
+    multimap()
+        _NOEXCEPT_(
+            is_nothrow_default_constructible<allocator_type>::value &&
+            is_nothrow_default_constructible<key_compare>::value &&
+            is_nothrow_copy_constructible<key_compare>::value)
+        : __tree_(__vc(key_compare())) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit multimap(const key_compare& __comp)
+        _NOEXCEPT_(
+            is_nothrow_default_constructible<allocator_type>::value &&
+            is_nothrow_copy_constructible<key_compare>::value)
+        : __tree_(__vc(__comp)) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit multimap(const key_compare& __comp, const allocator_type& __a)
+        : __tree_(__vc(__comp), __a) {}
+
+    template <class _InputIterator>
+        _LIBCPP_INLINE_VISIBILITY
+        multimap(_InputIterator __f, _InputIterator __l,
+            const key_compare& __comp = key_compare())
+        : __tree_(__vc(__comp))
+        {
+            insert(__f, __l);
+        }
+
+    template <class _InputIterator>
+        _LIBCPP_INLINE_VISIBILITY
+        multimap(_InputIterator __f, _InputIterator __l,
+            const key_compare& __comp, const allocator_type& __a)
+        : __tree_(__vc(__comp), __a)
+        {
+            insert(__f, __l);
+        }
+
+#if _LIBCPP_STD_VER > 11
+    template <class _InputIterator>
+    _LIBCPP_INLINE_VISIBILITY 
+    multimap(_InputIterator __f, _InputIterator __l, const allocator_type& __a)
+        : multimap(__f, __l, key_compare(), __a) {}
+#endif
+
+    _LIBCPP_INLINE_VISIBILITY
+    multimap(const multimap& __m)
+        : __tree_(__m.__tree_.value_comp(),
+          __alloc_traits::select_on_container_copy_construction(__m.__tree_.__alloc()))
+        {
+            insert(__m.begin(), __m.end());
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    multimap& operator=(const multimap& __m)
+        {
+#if __cplusplus >= 201103L
+            __tree_ = __m.__tree_;
+#else
+            if (this != &__m) {
+                __tree_.clear();
+                __tree_.value_comp() = __m.__tree_.value_comp();
+                __tree_.__copy_assign_alloc(__m.__tree_);
+                insert(__m.begin(), __m.end());
+            }
+#endif
+            return *this;
+        }
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY
+    multimap(multimap&& __m)
+        _NOEXCEPT_(is_nothrow_move_constructible<__base>::value)
+        : __tree_(_VSTD::move(__m.__tree_))
+        {
+        }
+
+    multimap(multimap&& __m, const allocator_type& __a);
+
+    _LIBCPP_INLINE_VISIBILITY
+    multimap& operator=(multimap&& __m)
+        _NOEXCEPT_(is_nothrow_move_assignable<__base>::value)
+        {
+            __tree_ = _VSTD::move(__m.__tree_);
+            return *this;
+        }
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+    _LIBCPP_INLINE_VISIBILITY
+    multimap(initializer_list<value_type> __il, const key_compare& __comp = key_compare())
+        : __tree_(__vc(__comp))
+        {
+            insert(__il.begin(), __il.end());
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    multimap(initializer_list<value_type> __il, const key_compare& __comp, const allocator_type& __a)
+        : __tree_(__vc(__comp), __a)
+        {
+            insert(__il.begin(), __il.end());
+        }
+
+#if _LIBCPP_STD_VER > 11
+    _LIBCPP_INLINE_VISIBILITY 
+    multimap(initializer_list<value_type> __il, const allocator_type& __a)
+        : multimap(__il, key_compare(), __a) {}
+#endif
+
+    _LIBCPP_INLINE_VISIBILITY
+    multimap& operator=(initializer_list<value_type> __il)
+        {
+            __tree_.__assign_multi(__il.begin(), __il.end());
+            return *this;
+        }
+
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit multimap(const allocator_type& __a)
+        : __tree_(__a)
+        {
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    multimap(const multimap& __m, const allocator_type& __a)
+        : __tree_(__m.__tree_.value_comp(), __a)
+        {
+            insert(__m.begin(), __m.end());
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+          iterator begin() _NOEXCEPT {return __tree_.begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator begin() const _NOEXCEPT {return __tree_.begin();}
+    _LIBCPP_INLINE_VISIBILITY
+          iterator end() _NOEXCEPT {return __tree_.end();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator end() const _NOEXCEPT {return __tree_.end();}
+
+    _LIBCPP_INLINE_VISIBILITY
+          reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator rbegin() const _NOEXCEPT
+        {return const_reverse_iterator(end());}
+    _LIBCPP_INLINE_VISIBILITY
+          reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator rend() const _NOEXCEPT
+        {return const_reverse_iterator(begin());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator cbegin()  const _NOEXCEPT {return begin();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator cend() const _NOEXCEPT {return end();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool empty() const _NOEXCEPT {return __tree_.size() == 0;}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type size() const _NOEXCEPT {return __tree_.size();}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type max_size() const _NOEXCEPT {return __tree_.max_size();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    allocator_type get_allocator() const _NOEXCEPT {return __tree_.__alloc();}
+    _LIBCPP_INLINE_VISIBILITY
+    key_compare    key_comp() const {return __tree_.value_comp().key_comp();}
+    _LIBCPP_INLINE_VISIBILITY
+    value_compare  value_comp() const
+        {return value_compare(__tree_.value_comp().key_comp());}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+    template <class ..._Args>
+        iterator
+        emplace(_Args&& ...__args);
+
+    template <class ..._Args>
+        iterator
+        emplace_hint(const_iterator __p, _Args&& ...__args);
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+    template <class _Pp,
+              class = typename enable_if<is_constructible<value_type, _Pp>::value>::type>
+        _LIBCPP_INLINE_VISIBILITY
+        iterator insert(_Pp&& __p)
+            {return __tree_.__insert_multi(_VSTD::forward<_Pp>(__p));}
+
+    template <class _Pp,
+              class = typename enable_if<is_constructible<value_type, _Pp>::value>::type>
+        _LIBCPP_INLINE_VISIBILITY
+        iterator insert(const_iterator __pos, _Pp&& __p)
+            {return __tree_.__insert_multi(__pos.__i_, _VSTD::forward<_Pp>(__p));}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator insert(const value_type& __v) {return __tree_.__insert_multi(__v);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator insert(const_iterator __p, const value_type& __v)
+            {return __tree_.__insert_multi(__p.__i_, __v);}
+
+    template <class _InputIterator>
+        _LIBCPP_INLINE_VISIBILITY
+        void insert(_InputIterator __f, _InputIterator __l)
+        {
+            for (const_iterator __e = cend(); __f != __l; ++__f)
+                __tree_.__insert_multi(__e.__i_, *__f);
+        }
+
+#ifndef _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+    _LIBCPP_INLINE_VISIBILITY
+    void insert(initializer_list<value_type> __il)
+        {insert(__il.begin(), __il.end());}
+
+#endif  // _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator erase(const_iterator __p) {return __tree_.erase(__p.__i_);}
+    _LIBCPP_INLINE_VISIBILITY
+    iterator erase(iterator __p)       {return __tree_.erase(__p.__i_);}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type erase(const key_type& __k) {return __tree_.__erase_multi(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    iterator  erase(const_iterator __f, const_iterator __l)
+        {return __tree_.erase(__f.__i_, __l.__i_);}
+    _LIBCPP_INLINE_VISIBILITY
+    void clear() {__tree_.clear();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(multimap& __m)
+        _NOEXCEPT_(__is_nothrow_swappable<__base>::value)
+        {__tree_.swap(__m.__tree_);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator find(const key_type& __k)             {return __tree_.find(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator find(const key_type& __k) const {return __tree_.find(__k);}
+#if _LIBCPP_STD_VER > 11
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
+    find(const _K2& __k)                           {return __tree_.find(__k);}
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
+    find(const _K2& __k) const                     {return __tree_.find(__k);}
+#endif
+
+    _LIBCPP_INLINE_VISIBILITY
+    size_type      count(const key_type& __k) const
+        {return __tree_.__count_multi(__k);}
+#if _LIBCPP_STD_VER > 11
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,size_type>::type
+    count(const _K2& __k) const {return __tree_.__count_multi(__k);}
+#endif
+    _LIBCPP_INLINE_VISIBILITY
+    iterator lower_bound(const key_type& __k)
+        {return __tree_.lower_bound(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator lower_bound(const key_type& __k) const
+            {return __tree_.lower_bound(__k);}
+#if _LIBCPP_STD_VER > 11
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
+    lower_bound(const _K2& __k)       {return __tree_.lower_bound(__k);}
+
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
+    lower_bound(const _K2& __k) const {return __tree_.lower_bound(__k);}
+#endif
+
+    _LIBCPP_INLINE_VISIBILITY
+    iterator upper_bound(const key_type& __k)
+            {return __tree_.upper_bound(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    const_iterator upper_bound(const key_type& __k) const
+            {return __tree_.upper_bound(__k);}
+#if _LIBCPP_STD_VER > 11
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
+    upper_bound(const _K2& __k)       {return __tree_.upper_bound(__k);}
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
+    upper_bound(const _K2& __k) const {return __tree_.upper_bound(__k);}
+#endif
+
+    _LIBCPP_INLINE_VISIBILITY
+    pair<iterator,iterator>             equal_range(const key_type& __k)
+            {return __tree_.__equal_range_multi(__k);}
+    _LIBCPP_INLINE_VISIBILITY
+    pair<const_iterator,const_iterator> equal_range(const key_type& __k) const
+            {return __tree_.__equal_range_multi(__k);}
+#if _LIBCPP_STD_VER > 11
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,pair<iterator,iterator>>::type
+    equal_range(const _K2& __k)       {return __tree_.__equal_range_multi(__k);}
+    template <typename _K2>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__is_transparent<_Compare, _K2>::value,pair<const_iterator,const_iterator>>::type
+    equal_range(const _K2& __k) const {return __tree_.__equal_range_multi(__k);}
+#endif
+
+private:
+    typedef typename __base::__node                    __node;
+    typedef typename __base::__node_allocator          __node_allocator;
+    typedef typename __base::__node_pointer            __node_pointer;
+    typedef typename __base::__node_const_pointer      __node_const_pointer;
+    typedef __map_node_destructor<__node_allocator> _Dp;
+    typedef unique_ptr<__node, _Dp> __node_holder;
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    __node_holder __construct_node();
+    template <class _A0>
+        __node_holder
+         __construct_node(_A0&& __a0);
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    template <class _A0, class _A1, class ..._Args>
+        __node_holder __construct_node(_A0&& __a0, _A1&& __a1, _Args&& ...__args);
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+};
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+multimap<_Key, _Tp, _Compare, _Allocator>::multimap(multimap&& __m, const allocator_type& __a)
+    : __tree_(_VSTD::move(__m.__tree_), __a)
+{
+    if (__a != __m.get_allocator())
+    {
+        const_iterator __e = cend();
+        while (!__m.empty())
+            __tree_.__insert_multi(__e.__i_,
+                    _VSTD::move(__m.__tree_.remove(__m.begin().__i_)->__value_));
+    }
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+typename multimap<_Key, _Tp, _Compare, _Allocator>::__node_holder
+multimap<_Key, _Tp, _Compare, _Allocator>::__construct_node()
+{
+    __node_allocator& __na = __tree_.__node_alloc();
+    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_.__cc.first));
+    __h.get_deleter().__first_constructed = true;
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_.__cc.second));
+    __h.get_deleter().__second_constructed = true;
+    return __h;
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+template <class _A0>
+typename multimap<_Key, _Tp, _Compare, _Allocator>::__node_holder
+multimap<_Key, _Tp, _Compare, _Allocator>::__construct_node(_A0&& __a0)
+{
+    __node_allocator& __na = __tree_.__node_alloc();
+    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_), _VSTD::forward<_A0>(__a0));
+    __h.get_deleter().__first_constructed = true;
+    __h.get_deleter().__second_constructed = true;
+    return __h;
+}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+template <class _A0, class _A1, class ..._Args>
+typename multimap<_Key, _Tp, _Compare, _Allocator>::__node_holder
+multimap<_Key, _Tp, _Compare, _Allocator>::__construct_node(_A0&& __a0, _A1&& __a1, _Args&& ...__args)
+{
+    __node_allocator& __na = __tree_.__node_alloc();
+    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
+    __node_traits::construct(__na, _VSTD::addressof(__h->__value_),
+                             _VSTD::forward<_A0>(__a0), _VSTD::forward<_A1>(__a1),
+                             _VSTD::forward<_Args>(__args)...);
+    __h.get_deleter().__first_constructed = true;
+    __h.get_deleter().__second_constructed = true;
+    return __h;
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+template <class ..._Args>
+typename multimap<_Key, _Tp, _Compare, _Allocator>::iterator
+multimap<_Key, _Tp, _Compare, _Allocator>::emplace(_Args&& ...__args)
+{
+    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
+    iterator __r = __tree_.__node_insert_multi(__h.get());
+    __h.release();
+    return __r;
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+template <class ..._Args>
+typename multimap<_Key, _Tp, _Compare, _Allocator>::iterator
+multimap<_Key, _Tp, _Compare, _Allocator>::emplace_hint(const_iterator __p,
+                                                        _Args&& ...__args)
+{
+    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
+    iterator __r = __tree_.__node_insert_multi(__p.__i_, __h.get());
+    __h.release();
+    return __r;
+}
+
+#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const multimap<_Key, _Tp, _Compare, _Allocator>& __x,
+           const multimap<_Key, _Tp, _Compare, _Allocator>& __y)
+{
+    return __x.size() == __y.size() && _VSTD::equal(__x.begin(), __x.end(), __y.begin());
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator< (const multimap<_Key, _Tp, _Compare, _Allocator>& __x,
+           const multimap<_Key, _Tp, _Compare, _Allocator>& __y)
+{
+    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const multimap<_Key, _Tp, _Compare, _Allocator>& __x,
+           const multimap<_Key, _Tp, _Compare, _Allocator>& __y)
+{
+    return !(__x == __y);
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator> (const multimap<_Key, _Tp, _Compare, _Allocator>& __x,
+           const multimap<_Key, _Tp, _Compare, _Allocator>& __y)
+{
+    return __y < __x;
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const multimap<_Key, _Tp, _Compare, _Allocator>& __x,
+           const multimap<_Key, _Tp, _Compare, _Allocator>& __y)
+{
+    return !(__x < __y);
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const multimap<_Key, _Tp, _Compare, _Allocator>& __x,
+           const multimap<_Key, _Tp, _Compare, _Allocator>& __y)
+{
+    return !(__y < __x);
+}
+
+template <class _Key, class _Tp, class _Compare, class _Allocator>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(multimap<_Key, _Tp, _Compare, _Allocator>& __x,
+     multimap<_Key, _Tp, _Compare, _Allocator>& __y)
+    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
+{
+    __x.swap(__y);
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_MAP

diff --git a/libcxx/include/memory b/libcxx/include/memory
new file mode 100644
index 0000000..df35a07
--- /dev/null
+++ b/libcxx/include/memory

@@ -0,0 +1,5580 @@
+// -*- C++ -*-
+//===-------------------------- memory ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_MEMORY
+#define _LIBCPP_MEMORY
+
+/*
+    memory synopsis
+
+namespace std
+{
+
+struct allocator_arg_t { };
+constexpr allocator_arg_t allocator_arg = allocator_arg_t();
+
+template <class T, class Alloc> struct uses_allocator;
+
+template <class Ptr>
+struct pointer_traits
+{
+    typedef Ptr pointer;
+    typedef <details> element_type;
+    typedef <details> difference_type;
+
+    template <class U> using rebind = <details>;
+
+    static pointer pointer_to(<details>);
+};
+
+template <class T>
+struct pointer_traits<T*>
+{
+    typedef T* pointer;
+    typedef T element_type;
+    typedef ptrdiff_t difference_type;
+
+    template <class U> using rebind = U*;
+
+    static pointer pointer_to(<details>) noexcept;
+};
+
+template <class Alloc>
+struct allocator_traits
+{
+    typedef Alloc                        allocator_type;
+    typedef typename allocator_type::value_type
+                                         value_type;
+
+    typedef Alloc::pointer | value_type* pointer;
+    typedef Alloc::const_pointer
+          | pointer_traits<pointer>::rebind<const value_type>
+                                         const_pointer;
+    typedef Alloc::void_pointer
+          | pointer_traits<pointer>::rebind<void>
+                                         void_pointer;
+    typedef Alloc::const_void_pointer
+          | pointer_traits<pointer>::rebind<const void>
+                                         const_void_pointer;
+    typedef Alloc::difference_type
+          | pointer_traits<pointer>::difference_type
+                                         difference_type;
+    typedef Alloc::size_type
+          | make_unsigned<difference_type>::type
+                                         size_type;
+    typedef Alloc::propagate_on_container_copy_assignment
+          | false_type                   propagate_on_container_copy_assignment;
+    typedef Alloc::propagate_on_container_move_assignment
+          | false_type                   propagate_on_container_move_assignment;
+    typedef Alloc::propagate_on_container_swap
+          | false_type                   propagate_on_container_swap;
+    typedef Alloc::is_always_equal
+          | is_empty                     is_always_equal;
+
+    template <class T> using rebind_alloc  = Alloc::rebind<U>::other | Alloc<T, Args...>;
+    template <class T> using rebind_traits = allocator_traits<rebind_alloc<T>>;
+
+    static pointer allocate(allocator_type& a, size_type n);
+    static pointer allocate(allocator_type& a, size_type n, const_void_pointer hint);
+
+    static void deallocate(allocator_type& a, pointer p, size_type n) noexcept;
+
+    template <class T, class... Args>
+        static void construct(allocator_type& a, T* p, Args&&... args);
+
+    template <class T>
+        static void destroy(allocator_type& a, T* p);
+
+    static size_type max_size(const allocator_type& a); // noexcept in C++14
+
+    static allocator_type
+        select_on_container_copy_construction(const allocator_type& a);
+};
+
+template <>
+class allocator<void>
+{
+public:
+    typedef void*                                 pointer;
+    typedef const void*                           const_pointer;
+    typedef void                                  value_type;
+
+    template <class _Up> struct rebind {typedef allocator<_Up> other;};
+};
+
+template <class T>
+class allocator
+{
+public:
+    typedef size_t                                size_type;
+    typedef ptrdiff_t                             difference_type;
+    typedef T*                                    pointer;
+    typedef const T*                              const_pointer;
+    typedef typename add_lvalue_reference<T>::type       reference;
+    typedef typename add_lvalue_reference<const T>::type const_reference;
+    typedef T                                     value_type;
+
+    template <class U> struct rebind {typedef allocator<U> other;};
+
+    allocator() noexcept;
+    allocator(const allocator&) noexcept;
+    template <class U> allocator(const allocator<U>&) noexcept;
+    ~allocator();
+    pointer address(reference x) const noexcept;
+    const_pointer address(const_reference x) const noexcept;
+    pointer allocate(size_type, allocator<void>::const_pointer hint = 0);
+    void deallocate(pointer p, size_type n) noexcept;
+    size_type max_size() const noexcept;
+    template<class U, class... Args>
+        void construct(U* p, Args&&... args);
+    template <class U>
+        void destroy(U* p);
+};
+
+template <class T, class U>
+bool operator==(const allocator<T>&, const allocator<U>&) noexcept;
+
+template <class T, class U>
+bool operator!=(const allocator<T>&, const allocator<U>&) noexcept;
+
+template <class OutputIterator, class T>
+class raw_storage_iterator
+    : public iterator<output_iterator_tag,
+                      T,                               // purposefully not C++03
+                      ptrdiff_t,                       // purposefully not C++03
+                      T*,                              // purposefully not C++03
+                      raw_storage_iterator&>           // purposefully not C++03
+{
+public:
+    explicit raw_storage_iterator(OutputIterator x);
+    raw_storage_iterator& operator*();
+    raw_storage_iterator& operator=(const T& element);
+    raw_storage_iterator& operator++();
+    raw_storage_iterator  operator++(int);
+};
+
+template <class T> pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
+template <class T> void               return_temporary_buffer(T* p) noexcept;
+
+template <class T> T* addressof(T& r) noexcept;
+
+template <class InputIterator, class ForwardIterator>
+ForwardIterator
+uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator result);
+
+template <class InputIterator, class Size, class ForwardIterator>
+ForwardIterator
+uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);
+
+template <class ForwardIterator, class T>
+void uninitialized_fill(ForwardIterator first, ForwardIterator last, const T& x);
+
+template <class ForwardIterator, class Size, class T>
+ForwardIterator
+uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
+
+template <class Y> struct auto_ptr_ref {};
+
+template<class X>
+class auto_ptr
+{
+public:
+    typedef X element_type;
+
+    explicit auto_ptr(X* p =0) throw();
+    auto_ptr(auto_ptr&) throw();
+    template<class Y> auto_ptr(auto_ptr<Y>&) throw();
+    auto_ptr& operator=(auto_ptr&) throw();
+    template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
+    auto_ptr& operator=(auto_ptr_ref<X> r) throw();
+    ~auto_ptr() throw();
+
+    typename add_lvalue_reference<X>::type operator*() const throw();
+    X* operator->() const throw();
+    X* get() const throw();
+    X* release() throw();
+    void reset(X* p =0) throw();
+
+    auto_ptr(auto_ptr_ref<X>) throw();
+    template<class Y> operator auto_ptr_ref<Y>() throw();
+    template<class Y> operator auto_ptr<Y>() throw();
+};
+
+template <class T>
+struct default_delete
+{
+    constexpr default_delete() noexcept = default;
+    template <class U> default_delete(const default_delete<U>&) noexcept;
+
+    void operator()(T*) const noexcept;
+};
+
+template <class T>
+struct default_delete<T[]>
+{
+    constexpr default_delete() noexcept = default;
+    void operator()(T*) const noexcept;
+    template <class U> void operator()(U*) const = delete;
+};
+
+template <class T, class D = default_delete<T>>
+class unique_ptr
+{
+public:
+    typedef see below pointer;
+    typedef T element_type;
+    typedef D deleter_type;
+
+    // constructors
+    constexpr unique_ptr() noexcept;
+    explicit unique_ptr(pointer p) noexcept;
+    unique_ptr(pointer p, see below d1) noexcept;
+    unique_ptr(pointer p, see below d2) noexcept;
+    unique_ptr(unique_ptr&& u) noexcept;
+    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
+    template <class U, class E>
+        unique_ptr(unique_ptr<U, E>&& u) noexcept;
+    template <class U>
+        unique_ptr(auto_ptr<U>&& u) noexcept;
+
+    // destructor
+    ~unique_ptr();
+
+    // assignment
+    unique_ptr& operator=(unique_ptr&& u) noexcept;
+    template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;
+    unique_ptr& operator=(nullptr_t) noexcept;
+
+    // observers
+    typename add_lvalue_reference<T>::type operator*() const;
+    pointer operator->() const noexcept;
+    pointer get() const noexcept;
+    deleter_type& get_deleter() noexcept;
+    const deleter_type& get_deleter() const noexcept;
+    explicit operator bool() const noexcept;
+
+    // modifiers
+    pointer release() noexcept;
+    void reset(pointer p = pointer()) noexcept;
+    void swap(unique_ptr& u) noexcept;
+};
+
+template <class T, class D>
+class unique_ptr<T[], D>
+{
+public:
+    typedef implementation-defined pointer;
+    typedef T element_type;
+    typedef D deleter_type;
+
+    // constructors
+    constexpr unique_ptr() noexcept;
+    explicit unique_ptr(pointer p) noexcept;
+    unique_ptr(pointer p, see below d) noexcept;
+    unique_ptr(pointer p, see below d) noexcept;
+    unique_ptr(unique_ptr&& u) noexcept;
+    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
+
+    // destructor
+    ~unique_ptr();
+
+    // assignment
+    unique_ptr& operator=(unique_ptr&& u) noexcept;
+    unique_ptr& operator=(nullptr_t) noexcept;
+
+    // observers
+    T& operator[](size_t i) const;
+    pointer get() const noexcept;
+    deleter_type& get_deleter() noexcept;
+    const deleter_type& get_deleter() const noexcept;
+    explicit operator bool() const noexcept;
+
+    // modifiers
+    pointer release() noexcept;
+    void reset(pointer p = pointer()) noexcept;
+    void reset(nullptr_t) noexcept;
+    template <class U> void reset(U) = delete;
+    void swap(unique_ptr& u) noexcept;
+};
+
+template <class T, class D>
+    void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;
+
+template <class T1, class D1, class T2, class D2>
+    bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+template <class T1, class D1, class T2, class D2>
+    bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+template <class T1, class D1, class T2, class D2>
+    bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+template <class T1, class D1, class T2, class D2>
+    bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+template <class T1, class D1, class T2, class D2>
+    bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+template <class T1, class D1, class T2, class D2>
+    bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
+
+template <class T, class D>
+    bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
+template <class T, class D>
+    bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;
+template <class T, class D>
+    bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
+template <class T, class D>
+    bool operator!=(nullptr_t, const unique_ptr<T, D>& y) noexcept;
+
+template <class T, class D>
+    bool operator<(const unique_ptr<T, D>& x, nullptr_t);
+template <class T, class D>
+    bool operator<(nullptr_t, const unique_ptr<T, D>& y);
+template <class T, class D>
+    bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
+template <class T, class D>
+    bool operator<=(nullptr_t, const unique_ptr<T, D>& y);
+template <class T, class D>
+    bool operator>(const unique_ptr<T, D>& x, nullptr_t);
+template <class T, class D>
+    bool operator>(nullptr_t, const unique_ptr<T, D>& y);
+template <class T, class D>
+    bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
+template <class T, class D>
+    bool operator>=(nullptr_t, const unique_ptr<T, D>& y);
+
+class bad_weak_ptr
+    : public std::exception
+{
+    bad_weak_ptr() noexcept;
+};
+
+template<class T, class... Args> unique_ptr<T> make_unique(Args&&... args);     // C++14
+template<class T>                unique_ptr<T> make_unique(size_t n);           // C++14
+template<class T, class... Args> unspecified   make_unique(Args&&...) = delete; // C++14, T == U[N]
+
+template<class T>
+class shared_ptr
+{
+public:
+    typedef T element_type;
+
+    // constructors:
+    constexpr shared_ptr() noexcept;
+    template<class Y> explicit shared_ptr(Y* p);
+    template<class Y, class D> shared_ptr(Y* p, D d);
+    template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
+    template <class D> shared_ptr(nullptr_t p, D d);
+    template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
+    template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
+    shared_ptr(const shared_ptr& r) noexcept;
+    template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
+    shared_ptr(shared_ptr&& r) noexcept;
+    template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
+    template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
+    template<class Y> shared_ptr(auto_ptr<Y>&& r);
+    template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
+    shared_ptr(nullptr_t) : shared_ptr() { }
+
+    // destructor:
+    ~shared_ptr();
+
+    // assignment:
+    shared_ptr& operator=(const shared_ptr& r) noexcept;
+    template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
+    shared_ptr& operator=(shared_ptr&& r) noexcept;
+    template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
+    template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r);
+    template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);
+
+    // modifiers:
+    void swap(shared_ptr& r) noexcept;
+    void reset() noexcept;
+    template<class Y> void reset(Y* p);
+    template<class Y, class D> void reset(Y* p, D d);
+    template<class Y, class D, class A> void reset(Y* p, D d, A a);
+
+    // observers:
+    T* get() const noexcept;
+    T& operator*() const noexcept;
+    T* operator->() const noexcept;
+    long use_count() const noexcept;
+    bool unique() const noexcept;
+    explicit operator bool() const noexcept;
+    template<class U> bool owner_before(shared_ptr<U> const& b) const;
+    template<class U> bool owner_before(weak_ptr<U> const& b) const;
+};
+
+// shared_ptr comparisons:
+template<class T, class U>
+    bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
+template<class T, class U>
+    bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
+template<class T, class U>
+    bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
+template<class T, class U>
+    bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
+template<class T, class U>
+    bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
+template<class T, class U>
+    bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
+
+template <class T>
+    bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept;
+template <class T>
+    bool operator==(nullptr_t, const shared_ptr<T>& y) noexcept;
+template <class T>
+    bool operator!=(const shared_ptr<T>& x, nullptr_t) noexcept;
+template <class T>
+    bool operator!=(nullptr_t, const shared_ptr<T>& y) noexcept;
+template <class T>
+    bool operator<(const shared_ptr<T>& x, nullptr_t) noexcept;
+template <class T>
+bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;
+template <class T>
+    bool operator<=(const shared_ptr<T>& x, nullptr_t) noexcept;
+template <class T>
+    bool operator<=(nullptr_t, const shared_ptr<T>& y) noexcept;
+template <class T>
+    bool operator>(const shared_ptr<T>& x, nullptr_t) noexcept;
+template <class T>
+    bool operator>(nullptr_t, const shared_ptr<T>& y) noexcept;
+template <class T>
+    bool operator>=(const shared_ptr<T>& x, nullptr_t) noexcept;
+template <class T>
+    bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;
+
+// shared_ptr specialized algorithms:
+template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
+
+// shared_ptr casts:
+template<class T, class U>
+    shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
+template<class T, class U>
+    shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
+template<class T, class U>
+    shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
+
+// shared_ptr I/O:
+template<class E, class T, class Y>
+    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
+
+// shared_ptr get_deleter:
+template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
+
+template<class T, class... Args>
+    shared_ptr<T> make_shared(Args&&... args);
+template<class T, class A, class... Args>
+    shared_ptr<T> allocate_shared(const A& a, Args&&... args);
+
+template<class T>
+class weak_ptr
+{
+public:
+    typedef T element_type;
+
+    // constructors
+    constexpr weak_ptr() noexcept;
+    template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
+    weak_ptr(weak_ptr const& r) noexcept;
+    template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
+    weak_ptr(weak_ptr&& r) noexcept;                      // C++14
+    template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14
+
+    // destructor
+    ~weak_ptr();
+
+    // assignment
+    weak_ptr& operator=(weak_ptr const& r) noexcept;
+    template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
+    template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
+    weak_ptr& operator=(weak_ptr&& r) noexcept;                      // C++14
+    template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14
+
+    // modifiers
+    void swap(weak_ptr& r) noexcept;
+    void reset() noexcept;
+
+    // observers
+    long use_count() const noexcept;
+    bool expired() const noexcept;
+    shared_ptr<T> lock() const noexcept;
+    template<class U> bool owner_before(shared_ptr<U> const& b) const;
+    template<class U> bool owner_before(weak_ptr<U> const& b) const;
+};
+
+// weak_ptr specialized algorithms:
+template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
+
+// class owner_less:
+template<class T> struct owner_less;
+
+template<class T>
+struct owner_less<shared_ptr<T>>
+    : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
+{
+    typedef bool result_type;
+    bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const;
+    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const;
+    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const;
+};
+
+template<class T>
+struct owner_less<weak_ptr<T>>
+    : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
+{
+    typedef bool result_type;
+    bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const;
+    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const;
+    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const;
+};
+
+template<class T>
+class enable_shared_from_this
+{
+protected:
+    constexpr enable_shared_from_this() noexcept;
+    enable_shared_from_this(enable_shared_from_this const&) noexcept;
+    enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
+    ~enable_shared_from_this();
+public:
+    shared_ptr<T> shared_from_this();
+    shared_ptr<T const> shared_from_this() const;
+};
+
+template<class T>
+    bool atomic_is_lock_free(const shared_ptr<T>* p);
+template<class T>
+    shared_ptr<T> atomic_load(const shared_ptr<T>* p);
+template<class T>
+    shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
+template<class T>
+    void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
+template<class T>
+    void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
+template<class T>
+    shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
+template<class T>
+    shared_ptr<T>
+    atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
+template<class T>
+    bool
+    atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
+template<class T>
+    bool
+    atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
+template<class T>
+    bool
+    atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
+                                          shared_ptr<T> w, memory_order success,
+                                          memory_order failure);
+template<class T>
+    bool
+    atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
+                                            shared_ptr<T> w, memory_order success,
+                                            memory_order failure);
+// Hash support
+template <class T> struct hash;
+template <class T, class D> struct hash<unique_ptr<T, D> >;
+template <class T> struct hash<shared_ptr<T> >;
+
+// Pointer safety
+enum class pointer_safety { relaxed, preferred, strict };
+void declare_reachable(void *p);
+template <class T> T *undeclare_reachable(T *p);
+void declare_no_pointers(char *p, size_t n);
+void undeclare_no_pointers(char *p, size_t n);
+pointer_safety get_pointer_safety() noexcept;
+
+void* align(size_t alignment, size_t size, void*& ptr, size_t& space);
+
+}  // std
+
+*/
+
+#include <__config>
+#include <type_traits>
+#include <typeinfo>
+#include <cstddef>
+#include <cstdint>
+#include <new>
+#include <utility>
+#include <limits>
+#include <iterator>
+#include <__functional_base>
+#include <iosfwd>
+#include <tuple>
+#include <cstring>
+#if defined(_LIBCPP_NO_EXCEPTIONS)
+    #include <cassert>
+#endif
+
+#if __has_feature(cxx_atomic) && !defined(_LIBCPP_HAS_NO_THREADS)
+#  include <atomic>
+#endif
+
+#include <__undef_min_max>
+#include <__undef___deallocate>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _ValueType>
+inline _LIBCPP_ALWAYS_INLINE
+_ValueType __libcpp_relaxed_load(_ValueType const* __value) {
+#if !defined(_LIBCPP_HAS_NO_THREADS) && \
+    defined(__ATOMIC_RELAXED) &&        \
+    (__has_builtin(__atomic_load_n) || _GNUC_VER >= 407)
+    return __atomic_load_n(__value, __ATOMIC_RELAXED);
+#else
+    return *__value;
+#endif
+}
+
+// addressof moved to <__functional_base>
+
+template <class _Tp> class allocator;
+
+template <>
+class _LIBCPP_TYPE_VIS_ONLY allocator<void>
+{
+public:
+    typedef void*             pointer;
+    typedef const void*       const_pointer;
+    typedef void              value_type;
+
+    template <class _Up> struct rebind {typedef allocator<_Up> other;};
+};
+
+template <>
+class _LIBCPP_TYPE_VIS_ONLY allocator<const void>
+{
+public:
+    typedef const void*       pointer;
+    typedef const void*       const_pointer;
+    typedef const void        value_type;
+
+    template <class _Up> struct rebind {typedef allocator<_Up> other;};
+};
+
+// pointer_traits
+
+template <class _Tp>
+struct __has_element_type
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Up> static __two __test(...);
+    template <class _Up> static char __test(typename _Up::element_type* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+template <class _Ptr, bool = __has_element_type<_Ptr>::value>
+struct __pointer_traits_element_type;
+
+template <class _Ptr>
+struct __pointer_traits_element_type<_Ptr, true>
+{
+    typedef typename _Ptr::element_type type;
+};
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <template <class, class...> class _Sp, class _Tp, class ..._Args>
+struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, true>
+{
+    typedef typename _Sp<_Tp, _Args...>::element_type type;
+};
+
+template <template <class, class...> class _Sp, class _Tp, class ..._Args>
+struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, false>
+{
+    typedef _Tp type;
+};
+
+#else  // _LIBCPP_HAS_NO_VARIADICS
+
+template <template <class> class _Sp, class _Tp>
+struct __pointer_traits_element_type<_Sp<_Tp>, true>
+{
+    typedef typename _Sp<_Tp>::element_type type;
+};
+
+template <template <class> class _Sp, class _Tp>
+struct __pointer_traits_element_type<_Sp<_Tp>, false>
+{
+    typedef _Tp type;
+};
+
+template <template <class, class> class _Sp, class _Tp, class _A0>
+struct __pointer_traits_element_type<_Sp<_Tp, _A0>, true>
+{
+    typedef typename _Sp<_Tp, _A0>::element_type type;
+};
+
+template <template <class, class> class _Sp, class _Tp, class _A0>
+struct __pointer_traits_element_type<_Sp<_Tp, _A0>, false>
+{
+    typedef _Tp type;
+};
+
+template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
+struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, true>
+{
+    typedef typename _Sp<_Tp, _A0, _A1>::element_type type;
+};
+
+template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
+struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, false>
+{
+    typedef _Tp type;
+};
+
+template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
+                                                           class _A1, class _A2>
+struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, true>
+{
+    typedef typename _Sp<_Tp, _A0, _A1, _A2>::element_type type;
+};
+
+template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
+                                                           class _A1, class _A2>
+struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, false>
+{
+    typedef _Tp type;
+};
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp>
+struct __has_difference_type
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Up> static __two __test(...);
+    template <class _Up> static char __test(typename _Up::difference_type* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+template <class _Ptr, bool = __has_difference_type<_Ptr>::value>
+struct __pointer_traits_difference_type
+{
+    typedef ptrdiff_t type;
+};
+
+template <class _Ptr>
+struct __pointer_traits_difference_type<_Ptr, true>
+{
+    typedef typename _Ptr::difference_type type;
+};
+
+template <class _Tp, class _Up>
+struct __has_rebind
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Xp> static __two __test(...);
+    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
+struct __pointer_traits_rebind
+{
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+    typedef typename _Tp::template rebind<_Up> type;
+#else
+    typedef typename _Tp::template rebind<_Up>::other type;
+#endif
+};
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
+struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, true>
+{
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+    typedef typename _Sp<_Tp, _Args...>::template rebind<_Up> type;
+#else
+    typedef typename _Sp<_Tp, _Args...>::template rebind<_Up>::other type;
+#endif
+};
+
+template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
+struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, false>
+{
+    typedef _Sp<_Up, _Args...> type;
+};
+
+#else  // _LIBCPP_HAS_NO_VARIADICS
+
+template <template <class> class _Sp, class _Tp, class _Up>
+struct __pointer_traits_rebind<_Sp<_Tp>, _Up, true>
+{
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+    typedef typename _Sp<_Tp>::template rebind<_Up> type;
+#else
+    typedef typename _Sp<_Tp>::template rebind<_Up>::other type;
+#endif
+};
+
+template <template <class> class _Sp, class _Tp, class _Up>
+struct __pointer_traits_rebind<_Sp<_Tp>, _Up, false>
+{
+    typedef _Sp<_Up> type;
+};
+
+template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
+struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, true>
+{
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+    typedef typename _Sp<_Tp, _A0>::template rebind<_Up> type;
+#else
+    typedef typename _Sp<_Tp, _A0>::template rebind<_Up>::other type;
+#endif
+};
+
+template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
+struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, false>
+{
+    typedef _Sp<_Up, _A0> type;
+};
+
+template <template <class, class, class> class _Sp, class _Tp, class _A0,
+                                         class _A1, class _Up>
+struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, true>
+{
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+    typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up> type;
+#else
+    typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up>::other type;
+#endif
+};
+
+template <template <class, class, class> class _Sp, class _Tp, class _A0,
+                                         class _A1, class _Up>
+struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, false>
+{
+    typedef _Sp<_Up, _A0, _A1> type;
+};
+
+template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
+                                                class _A1, class _A2, class _Up>
+struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, true>
+{
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+    typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up> type;
+#else
+    typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
+#endif
+};
+
+template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
+                                                class _A1, class _A2, class _Up>
+struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, false>
+{
+    typedef _Sp<_Up, _A0, _A1, _A2> type;
+};
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Ptr>
+struct _LIBCPP_TYPE_VIS_ONLY pointer_traits
+{
+    typedef _Ptr                                                     pointer;
+    typedef typename __pointer_traits_element_type<pointer>::type    element_type;
+    typedef typename __pointer_traits_difference_type<pointer>::type difference_type;
+
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+    template <class _Up> using rebind = typename __pointer_traits_rebind<pointer, _Up>::type;
+#else
+    template <class _Up> struct rebind
+        {typedef typename __pointer_traits_rebind<pointer, _Up>::type other;};
+#endif  // _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+
+private:
+    struct __nat {};
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    static pointer pointer_to(typename conditional<is_void<element_type>::value,
+                                           __nat, element_type>::type& __r)
+        {return pointer::pointer_to(__r);}
+};
+
+template <class _Tp>
+struct _LIBCPP_TYPE_VIS_ONLY pointer_traits<_Tp*>
+{
+    typedef _Tp*      pointer;
+    typedef _Tp       element_type;
+    typedef ptrdiff_t difference_type;
+
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+    template <class _Up> using rebind = _Up*;
+#else
+    template <class _Up> struct rebind {typedef _Up* other;};
+#endif
+
+private:
+    struct __nat {};
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    static pointer pointer_to(typename conditional<is_void<element_type>::value,
+                                      __nat, element_type>::type& __r) _NOEXCEPT
+        {return _VSTD::addressof(__r);}
+};
+
+// allocator_traits
+
+namespace __has_pointer_type_imp
+{
+    template <class _Up> static __two __test(...);
+    template <class _Up> static char __test(typename _Up::pointer* = 0);
+}
+
+template <class _Tp>
+struct __has_pointer_type
+    : public integral_constant<bool, sizeof(__has_pointer_type_imp::__test<_Tp>(0)) == 1>
+{
+};
+
+namespace __pointer_type_imp
+{
+
+template <class _Tp, class _Dp, bool = __has_pointer_type<_Dp>::value>
+struct __pointer_type
+{
+    typedef typename _Dp::pointer type;
+};
+
+template <class _Tp, class _Dp>
+struct __pointer_type<_Tp, _Dp, false>
+{
+    typedef _Tp* type;
+};
+
+}  // __pointer_type_imp
+
+template <class _Tp, class _Dp>
+struct __pointer_type
+{
+    typedef typename __pointer_type_imp::__pointer_type<_Tp, typename remove_reference<_Dp>::type>::type type;
+};
+
+template <class _Tp>
+struct __has_const_pointer
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Up> static __two __test(...);
+    template <class _Up> static char __test(typename _Up::const_pointer* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+template <class _Tp, class _Ptr, class _Alloc, bool = __has_const_pointer<_Alloc>::value>
+struct __const_pointer
+{
+    typedef typename _Alloc::const_pointer type;
+};
+
+template <class _Tp, class _Ptr, class _Alloc>
+struct __const_pointer<_Tp, _Ptr, _Alloc, false>
+{
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+    typedef typename pointer_traits<_Ptr>::template rebind<const _Tp> type;
+#else
+    typedef typename pointer_traits<_Ptr>::template rebind<const _Tp>::other type;
+#endif
+};
+
+template <class _Tp>
+struct __has_void_pointer
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Up> static __two __test(...);
+    template <class _Up> static char __test(typename _Up::void_pointer* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+template <class _Ptr, class _Alloc, bool = __has_void_pointer<_Alloc>::value>
+struct __void_pointer
+{
+    typedef typename _Alloc::void_pointer type;
+};
+
+template <class _Ptr, class _Alloc>
+struct __void_pointer<_Ptr, _Alloc, false>
+{
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+    typedef typename pointer_traits<_Ptr>::template rebind<void> type;
+#else
+    typedef typename pointer_traits<_Ptr>::template rebind<void>::other type;
+#endif
+};
+
+template <class _Tp>
+struct __has_const_void_pointer
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Up> static __two __test(...);
+    template <class _Up> static char __test(typename _Up::const_void_pointer* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+template <class _Ptr, class _Alloc, bool = __has_const_void_pointer<_Alloc>::value>
+struct __const_void_pointer
+{
+    typedef typename _Alloc::const_void_pointer type;
+};
+
+template <class _Ptr, class _Alloc>
+struct __const_void_pointer<_Ptr, _Alloc, false>
+{
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+    typedef typename pointer_traits<_Ptr>::template rebind<const void> type;
+#else
+    typedef typename pointer_traits<_Ptr>::template rebind<const void>::other type;
+#endif
+};
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp*
+__to_raw_pointer(_Tp* __p) _NOEXCEPT
+{
+    return __p;
+}
+
+template <class _Pointer>
+inline _LIBCPP_INLINE_VISIBILITY
+typename pointer_traits<_Pointer>::element_type*
+__to_raw_pointer(_Pointer __p) _NOEXCEPT
+{
+    return _VSTD::__to_raw_pointer(__p.operator->());
+}
+
+template <class _Tp>
+struct __has_size_type
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Up> static __two __test(...);
+    template <class _Up> static char __test(typename _Up::size_type* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+template <class _Alloc, class _DiffType, bool = __has_size_type<_Alloc>::value>
+struct __size_type
+{
+    typedef typename make_unsigned<_DiffType>::type type;
+};
+
+template <class _Alloc, class _DiffType>
+struct __size_type<_Alloc, _DiffType, true>
+{
+    typedef typename _Alloc::size_type type;
+};
+
+template <class _Tp>
+struct __has_propagate_on_container_copy_assignment
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Up> static __two __test(...);
+    template <class _Up> static char __test(typename _Up::propagate_on_container_copy_assignment* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+template <class _Alloc, bool = __has_propagate_on_container_copy_assignment<_Alloc>::value>
+struct __propagate_on_container_copy_assignment
+{
+    typedef false_type type;
+};
+
+template <class _Alloc>
+struct __propagate_on_container_copy_assignment<_Alloc, true>
+{
+    typedef typename _Alloc::propagate_on_container_copy_assignment type;
+};
+
+template <class _Tp>
+struct __has_propagate_on_container_move_assignment
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Up> static __two __test(...);
+    template <class _Up> static char __test(typename _Up::propagate_on_container_move_assignment* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+template <class _Alloc, bool = __has_propagate_on_container_move_assignment<_Alloc>::value>
+struct __propagate_on_container_move_assignment
+{
+    typedef false_type type;
+};
+
+template <class _Alloc>
+struct __propagate_on_container_move_assignment<_Alloc, true>
+{
+    typedef typename _Alloc::propagate_on_container_move_assignment type;
+};
+
+template <class _Tp>
+struct __has_propagate_on_container_swap
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Up> static __two __test(...);
+    template <class _Up> static char __test(typename _Up::propagate_on_container_swap* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+template <class _Alloc, bool = __has_propagate_on_container_swap<_Alloc>::value>
+struct __propagate_on_container_swap
+{
+    typedef false_type type;
+};
+
+template <class _Alloc>
+struct __propagate_on_container_swap<_Alloc, true>
+{
+    typedef typename _Alloc::propagate_on_container_swap type;
+};
+
+template <class _Tp>
+struct __has_is_always_equal
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Up> static __two __test(...);
+    template <class _Up> static char __test(typename _Up::is_always_equal* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+template <class _Alloc, bool = __has_is_always_equal<_Alloc>::value>
+struct __is_always_equal
+{
+    typedef typename _VSTD::is_empty<_Alloc>::type type;
+};
+
+template <class _Alloc>
+struct __is_always_equal<_Alloc, true>
+{
+    typedef typename _Alloc::is_always_equal type;
+};
+
+template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
+struct __has_rebind_other
+{
+private:
+    struct __two {char __lx; char __lxx;};
+    template <class _Xp> static __two __test(...);
+    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>::other* = 0);
+public:
+    static const bool value = sizeof(__test<_Tp>(0)) == 1;
+};
+
+template <class _Tp, class _Up>
+struct __has_rebind_other<_Tp, _Up, false>
+{
+    static const bool value = false;
+};
+
+template <class _Tp, class _Up, bool = __has_rebind_other<_Tp, _Up>::value>
+struct __allocator_traits_rebind
+{
+    typedef typename _Tp::template rebind<_Up>::other type;
+};
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
+struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, true>
+{
+    typedef typename _Alloc<_Tp, _Args...>::template rebind<_Up>::other type;
+};
+
+template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
+struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, false>
+{
+    typedef _Alloc<_Up, _Args...> type;
+};
+
+#else  // _LIBCPP_HAS_NO_VARIADICS
+
+template <template <class> class _Alloc, class _Tp, class _Up>
+struct __allocator_traits_rebind<_Alloc<_Tp>, _Up, true>
+{
+    typedef typename _Alloc<_Tp>::template rebind<_Up>::other type;
+};
+
+template <template <class> class _Alloc, class _Tp, class _Up>
+struct __allocator_traits_rebind<_Alloc<_Tp>, _Up, false>
+{
+    typedef _Alloc<_Up> type;
+};
+
+template <template <class, class> class _Alloc, class _Tp, class _A0, class _Up>
+struct __allocator_traits_rebind<_Alloc<_Tp, _A0>, _Up, true>
+{
+    typedef typename _Alloc<_Tp, _A0>::template rebind<_Up>::other type;
+};
+
+template <template <class, class> class _Alloc, class _Tp, class _A0, class _Up>
+struct __allocator_traits_rebind<_Alloc<_Tp, _A0>, _Up, false>
+{
+    typedef _Alloc<_Up, _A0> type;
+};
+
+template <template <class, class, class> class _Alloc, class _Tp, class _A0,
+                                         class _A1, class _Up>
+struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1>, _Up, true>
+{
+    typedef typename _Alloc<_Tp, _A0, _A1>::template rebind<_Up>::other type;
+};
+
+template <template <class, class, class> class _Alloc, class _Tp, class _A0,
+                                         class _A1, class _Up>
+struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1>, _Up, false>
+{
+    typedef _Alloc<_Up, _A0, _A1> type;
+};
+
+template <template <class, class, class, class> class _Alloc, class _Tp, class _A0,
+                                                class _A1, class _A2, class _Up>
+struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1, _A2>, _Up, true>
+{
+    typedef typename _Alloc<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
+};
+
+template <template <class, class, class, class> class _Alloc, class _Tp, class _A0,
+                                                class _A1, class _A2, class _Up>
+struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1, _A2>, _Up, false>
+{
+    typedef _Alloc<_Up, _A0, _A1, _A2> type;
+};
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+#ifndef _LIBCPP_HAS_NO_ADVANCED_SFINAE
+
+template <class _Alloc, class _SizeType, class _ConstVoidPtr>
+auto
+__has_allocate_hint_test(_Alloc&& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
+    -> decltype(__a.allocate(__sz, __p), true_type());
+
+template <class _Alloc, class _SizeType, class _ConstVoidPtr>
+auto
+__has_allocate_hint_test(const _Alloc& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
+    -> false_type;
+
+template <class _Alloc, class _SizeType, class _ConstVoidPtr>
+struct __has_allocate_hint
+    : integral_constant<bool,
+        is_same<
+            decltype(__has_allocate_hint_test(declval<_Alloc>(),
+                                          declval<_SizeType>(),
+                                          declval<_ConstVoidPtr>())),
+            true_type>::value>
+{
+};
+
+#else  // _LIBCPP_HAS_NO_ADVANCED_SFINAE
+
+template <class _Alloc, class _SizeType, class _ConstVoidPtr>
+struct __has_allocate_hint
+    : true_type
+{
+};
+
+#endif  // _LIBCPP_HAS_NO_ADVANCED_SFINAE
+
+#if !defined(_LIBCPP_HAS_NO_ADVANCED_SFINAE) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+
+template <class _Alloc, class _Tp, class ..._Args>
+decltype(_VSTD::declval<_Alloc>().construct(_VSTD::declval<_Tp*>(),
+                                           _VSTD::declval<_Args>()...),
+                                           true_type())
+__has_construct_test(_Alloc&& __a, _Tp* __p, _Args&& ...__args);
+
+template <class _Alloc, class _Pointer, class ..._Args>
+false_type
+__has_construct_test(const _Alloc& __a, _Pointer&& __p, _Args&& ...__args);
+
+template <class _Alloc, class _Pointer, class ..._Args>
+struct __has_construct
+    : integral_constant<bool,
+        is_same<
+            decltype(__has_construct_test(declval<_Alloc>(),
+                                          declval<_Pointer>(),
+                                          declval<_Args>()...)),
+            true_type>::value>
+{
+};
+
+template <class _Alloc, class _Pointer>
+auto
+__has_destroy_test(_Alloc&& __a, _Pointer&& __p)
+    -> decltype(__a.destroy(__p), true_type());
+
+template <class _Alloc, class _Pointer>
+auto
+__has_destroy_test(const _Alloc& __a, _Pointer&& __p)
+    -> false_type;
+
+template <class _Alloc, class _Pointer>
+struct __has_destroy
+    : integral_constant<bool,
+        is_same<
+            decltype(__has_destroy_test(declval<_Alloc>(),
+                                        declval<_Pointer>())),
+            true_type>::value>
+{
+};
+
+template <class _Alloc>
+auto
+__has_max_size_test(_Alloc&& __a)
+    -> decltype(__a.max_size(), true_type());
+
+template <class _Alloc>
+auto
+__has_max_size_test(const volatile _Alloc& __a)
+    -> false_type;
+
+template <class _Alloc>
+struct __has_max_size
+    : integral_constant<bool,
+        is_same<
+            decltype(__has_max_size_test(declval<_Alloc&>())),
+            true_type>::value>
+{
+};
+
+template <class _Alloc>
+auto
+__has_select_on_container_copy_construction_test(_Alloc&& __a)
+    -> decltype(__a.select_on_container_copy_construction(), true_type());
+
+template <class _Alloc>
+auto
+__has_select_on_container_copy_construction_test(const volatile _Alloc& __a)
+    -> false_type;
+
+template <class _Alloc>
+struct __has_select_on_container_copy_construction
+    : integral_constant<bool,
+        is_same<
+            decltype(__has_select_on_container_copy_construction_test(declval<_Alloc&>())),
+            true_type>::value>
+{
+};
+
+#else  // _LIBCPP_HAS_NO_ADVANCED_SFINAE
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Alloc, class _Pointer, class ..._Args>
+struct __has_construct
+    : false_type
+{
+};
+
+#else  // _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Alloc, class _Pointer, class _Args>
+struct __has_construct
+    : false_type
+{
+};
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Alloc, class _Pointer>
+struct __has_destroy
+    : false_type
+{
+};
+
+template <class _Alloc>
+struct __has_max_size
+    : true_type
+{
+};
+
+template <class _Alloc>
+struct __has_select_on_container_copy_construction
+    : false_type
+{
+};
+
+#endif  // _LIBCPP_HAS_NO_ADVANCED_SFINAE
+
+template <class _Alloc, class _Ptr, bool = __has_difference_type<_Alloc>::value>
+struct __alloc_traits_difference_type
+{
+    typedef typename pointer_traits<_Ptr>::difference_type type;
+};
+
+template <class _Alloc, class _Ptr>
+struct __alloc_traits_difference_type<_Alloc, _Ptr, true>
+{
+    typedef typename _Alloc::difference_type type;
+};
+
+template <class _Alloc>
+struct _LIBCPP_TYPE_VIS_ONLY allocator_traits
+{
+    typedef _Alloc                              allocator_type;
+    typedef typename allocator_type::value_type value_type;
+
+    typedef typename __pointer_type<value_type, allocator_type>::type pointer;
+    typedef typename __const_pointer<value_type, pointer, allocator_type>::type const_pointer;
+    typedef typename __void_pointer<pointer, allocator_type>::type void_pointer;
+    typedef typename __const_void_pointer<pointer, allocator_type>::type const_void_pointer;
+
+    typedef typename __alloc_traits_difference_type<allocator_type, pointer>::type difference_type;
+    typedef typename __size_type<allocator_type, difference_type>::type size_type;
+
+    typedef typename __propagate_on_container_copy_assignment<allocator_type>::type
+                     propagate_on_container_copy_assignment;
+    typedef typename __propagate_on_container_move_assignment<allocator_type>::type
+                     propagate_on_container_move_assignment;
+    typedef typename __propagate_on_container_swap<allocator_type>::type
+                     propagate_on_container_swap;
+    typedef typename __is_always_equal<allocator_type>::type
+                     is_always_equal;
+
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+    template <class _Tp> using rebind_alloc =
+                  typename __allocator_traits_rebind<allocator_type, _Tp>::type;
+    template <class _Tp> using rebind_traits = allocator_traits<rebind_alloc<_Tp>>;
+#else  // _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+    template <class _Tp> struct rebind_alloc
+        {typedef typename __allocator_traits_rebind<allocator_type, _Tp>::type other;};
+    template <class _Tp> struct rebind_traits
+        {typedef allocator_traits<typename rebind_alloc<_Tp>::other> other;};
+#endif  // _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+
+    _LIBCPP_INLINE_VISIBILITY
+    static pointer allocate(allocator_type& __a, size_type __n)
+        {return __a.allocate(__n);}
+    _LIBCPP_INLINE_VISIBILITY
+    static pointer allocate(allocator_type& __a, size_type __n, const_void_pointer __hint)
+        {return allocate(__a, __n, __hint,
+            __has_allocate_hint<allocator_type, size_type, const_void_pointer>());}
+
+    _LIBCPP_INLINE_VISIBILITY
+    static void deallocate(allocator_type& __a, pointer __p, size_type __n) _NOEXCEPT
+        {__a.deallocate(__p, __n);}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    template <class _Tp, class... _Args>
+        _LIBCPP_INLINE_VISIBILITY
+        static void construct(allocator_type& __a, _Tp* __p, _Args&&... __args)
+            {__construct(__has_construct<allocator_type, _Tp*, _Args...>(),
+                         __a, __p, _VSTD::forward<_Args>(__args)...);}
+#else  // _LIBCPP_HAS_NO_VARIADICS
+    template <class _Tp>
+        _LIBCPP_INLINE_VISIBILITY
+        static void construct(allocator_type& __a, _Tp* __p)
+            {
+                ::new ((void*)__p) _Tp();
+            }
+    template <class _Tp, class _A0>
+        _LIBCPP_INLINE_VISIBILITY
+        static void construct(allocator_type& __a, _Tp* __p, const _A0& __a0)
+            {
+                ::new ((void*)__p) _Tp(__a0);
+            }
+    template <class _Tp, class _A0, class _A1>
+        _LIBCPP_INLINE_VISIBILITY
+        static void construct(allocator_type& __a, _Tp* __p, const _A0& __a0,
+                              const _A1& __a1)
+            {
+                ::new ((void*)__p) _Tp(__a0, __a1);
+            }
+    template <class _Tp, class _A0, class _A1, class _A2>
+        _LIBCPP_INLINE_VISIBILITY
+        static void construct(allocator_type& __a, _Tp* __p, const _A0& __a0,
+                              const _A1& __a1, const _A2& __a2)
+            {
+                ::new ((void*)__p) _Tp(__a0, __a1, __a2);
+            }
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+    template <class _Tp>
+        _LIBCPP_INLINE_VISIBILITY
+        static void destroy(allocator_type& __a, _Tp* __p)
+            {__destroy(__has_destroy<allocator_type, _Tp*>(), __a, __p);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    static size_type max_size(const allocator_type& __a) _NOEXCEPT
+        {return __max_size(__has_max_size<const allocator_type>(), __a);}
+
+    _LIBCPP_INLINE_VISIBILITY
+    static allocator_type
+        select_on_container_copy_construction(const allocator_type& __a)
+            {return select_on_container_copy_construction(
+                __has_select_on_container_copy_construction<const allocator_type>(),
+                __a);}
+
+    template <class _Ptr>
+        _LIBCPP_INLINE_VISIBILITY
+        static
+        void
+        __construct_forward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2)
+        {
+            for (; __begin1 != __end1; ++__begin1, ++__begin2)
+                construct(__a, _VSTD::__to_raw_pointer(__begin2), _VSTD::move_if_noexcept(*__begin1));
+        }
+
+    template <class _Tp>
+        _LIBCPP_INLINE_VISIBILITY
+        static
+        typename enable_if
+        <
+            (is_same<allocator_type, allocator<_Tp> >::value
+                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
+             is_trivially_move_constructible<_Tp>::value,
+            void
+        >::type
+        __construct_forward(allocator_type& __a, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2)
+        {
+            ptrdiff_t _Np = __end1 - __begin1;
+            if (_Np > 0)
+            {
+                _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
+                __begin2 += _Np;
+            }
+        }
+
+    template <class _Iter, class _Ptr>
+        _LIBCPP_INLINE_VISIBILITY
+        static
+        void
+        __construct_range_forward(allocator_type& __a, _Iter __begin1, _Iter __end1, _Ptr& __begin2)
+        {
+            for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
+                construct(__a, _VSTD::__to_raw_pointer(__begin2), *__begin1);
+        }
+
+    template <class _Tp>
+        _LIBCPP_INLINE_VISIBILITY
+        static
+        typename enable_if
+        <
+            (is_same<allocator_type, allocator<_Tp> >::value
+                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
+             is_trivially_move_constructible<_Tp>::value,
+            void
+        >::type
+        __construct_range_forward(allocator_type& __a, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2)
+        {
+            typedef typename remove_const<_Tp>::type _Vp;
+            ptrdiff_t _Np = __end1 - __begin1;
+            if (_Np > 0)
+            {
+                _VSTD::memcpy(const_cast<_Vp*>(__begin2), __begin1, _Np * sizeof(_Tp));
+                __begin2 += _Np;
+            }
+        }
+
+    template <class _Ptr>
+        _LIBCPP_INLINE_VISIBILITY
+        static
+        void
+        __construct_backward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __end2)
+        {
+            while (__end1 != __begin1)
+            {
+                construct(__a, _VSTD::__to_raw_pointer(__end2-1), _VSTD::move_if_noexcept(*--__end1));
+                --__end2;
+            }
+        }
+
+    template <class _Tp>
+        _LIBCPP_INLINE_VISIBILITY
+        static
+        typename enable_if
+        <
+            (is_same<allocator_type, allocator<_Tp> >::value
+                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
+             is_trivially_move_constructible<_Tp>::value,
+            void
+        >::type
+        __construct_backward(allocator_type& __a, _Tp* __begin1, _Tp* __end1, _Tp*& __end2)
+        {
+            ptrdiff_t _Np = __end1 - __begin1;
+            __end2 -= _Np;
+            if (_Np > 0)
+                _VSTD::memcpy(__end2, __begin1, _Np * sizeof(_Tp));
+        }
+
+private:
+
+    _LIBCPP_INLINE_VISIBILITY
+    static pointer allocate(allocator_type& __a, size_type __n,
+        const_void_pointer __hint, true_type)
+        {return __a.allocate(__n, __hint);}
+    _LIBCPP_INLINE_VISIBILITY
+    static pointer allocate(allocator_type& __a, size_type __n,
+        const_void_pointer, false_type)
+        {return __a.allocate(__n);}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    template <class _Tp, class... _Args>
+        _LIBCPP_INLINE_VISIBILITY
+        static void __construct(true_type, allocator_type& __a, _Tp* __p, _Args&&... __args)
+            {__a.construct(__p, _VSTD::forward<_Args>(__args)...);}
+    template <class _Tp, class... _Args>
+        _LIBCPP_INLINE_VISIBILITY
+        static void __construct(false_type, allocator_type&, _Tp* __p, _Args&&... __args)
+            {
+                ::new ((void*)__p) _Tp(_VSTD::forward<_Args>(__args)...);
+            }
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+    template <class _Tp>
+        _LIBCPP_INLINE_VISIBILITY
+        static void __destroy(true_type, allocator_type& __a, _Tp* __p)
+            {__a.destroy(__p);}
+    template <class _Tp>
+        _LIBCPP_INLINE_VISIBILITY
+        static void __destroy(false_type, allocator_type&, _Tp* __p)
+            {
+                __p->~_Tp();
+            }
+
+    _LIBCPP_INLINE_VISIBILITY
+    static size_type __max_size(true_type, const allocator_type& __a)
+            {return __a.max_size();}
+    _LIBCPP_INLINE_VISIBILITY
+    static size_type __max_size(false_type, const allocator_type&)
+            {return numeric_limits<size_type>::max();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    static allocator_type
+        select_on_container_copy_construction(true_type, const allocator_type& __a)
+            {return __a.select_on_container_copy_construction();}
+    _LIBCPP_INLINE_VISIBILITY
+    static allocator_type
+        select_on_container_copy_construction(false_type, const allocator_type& __a)
+            {return __a;}
+};
+
+template <class _Traits, class _Tp>
+struct __rebind_alloc_helper
+{
+#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
+    typedef typename _Traits::template rebind_alloc<_Tp>        type;
+#else
+    typedef typename _Traits::template rebind_alloc<_Tp>::other type;
+#endif
+};
+
+// allocator
+
+template <class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY allocator
+{
+public:
+    typedef size_t            size_type;
+    typedef ptrdiff_t         difference_type;
+    typedef _Tp*              pointer;
+    typedef const _Tp*        const_pointer;
+    typedef _Tp&              reference;
+    typedef const _Tp&        const_reference;
+    typedef _Tp               value_type;
+
+    typedef true_type propagate_on_container_move_assignment;
+    typedef true_type is_always_equal;
+
+    template <class _Up> struct rebind {typedef allocator<_Up> other;};
+
+    _LIBCPP_INLINE_VISIBILITY allocator() _NOEXCEPT {}
+    template <class _Up> _LIBCPP_INLINE_VISIBILITY allocator(const allocator<_Up>&) _NOEXCEPT {}
+    _LIBCPP_INLINE_VISIBILITY pointer address(reference __x) const _NOEXCEPT
+        {return _VSTD::addressof(__x);}
+    _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x) const _NOEXCEPT
+        {return _VSTD::addressof(__x);}
+    _LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
+        {return static_cast<pointer>(_VSTD::__allocate(__n * sizeof(_Tp)));}
+    _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type) _NOEXCEPT
+        {_VSTD::__deallocate((void*)__p);}
+    _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
+        {return size_type(~0) / sizeof(_Tp);}
+#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+    template <class _Up, class... _Args>
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        construct(_Up* __p, _Args&&... __args)
+        {
+            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
+        }
+#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        construct(pointer __p)
+        {
+            ::new((void*)__p) _Tp();
+        }
+# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+
+    template <class _A0>
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        construct(pointer __p, _A0& __a0)
+        {
+            ::new((void*)__p) _Tp(__a0);
+        }
+    template <class _A0>
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        construct(pointer __p, const _A0& __a0)
+        {
+            ::new((void*)__p) _Tp(__a0);
+        }
+# endif  // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+    template <class _A0, class _A1>
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        construct(pointer __p, _A0& __a0, _A1& __a1)
+        {
+            ::new((void*)__p) _Tp(__a0, __a1);
+        }
+    template <class _A0, class _A1>
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        construct(pointer __p, const _A0& __a0, _A1& __a1)
+        {
+            ::new((void*)__p) _Tp(__a0, __a1);
+        }
+    template <class _A0, class _A1>
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        construct(pointer __p, _A0& __a0, const _A1& __a1)
+        {
+            ::new((void*)__p) _Tp(__a0, __a1);
+        }
+    template <class _A0, class _A1>
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        construct(pointer __p, const _A0& __a0, const _A1& __a1)
+        {
+            ::new((void*)__p) _Tp(__a0, __a1);
+        }
+#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+    _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
+};
+
+template <class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY allocator<const _Tp>
+{
+public:
+    typedef size_t            size_type;
+    typedef ptrdiff_t         difference_type;
+    typedef const _Tp*        pointer;
+    typedef const _Tp*        const_pointer;
+    typedef const _Tp&        reference;
+    typedef const _Tp&        const_reference;
+    typedef const _Tp         value_type;
+
+    typedef true_type propagate_on_container_move_assignment;
+    typedef true_type is_always_equal;
+
+    template <class _Up> struct rebind {typedef allocator<_Up> other;};
+
+    _LIBCPP_INLINE_VISIBILITY allocator() _NOEXCEPT {}
+    template <class _Up> _LIBCPP_INLINE_VISIBILITY allocator(const allocator<_Up>&) _NOEXCEPT {}
+    _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x) const _NOEXCEPT
+        {return _VSTD::addressof(__x);}
+    _LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
+        {return static_cast<pointer>(_VSTD::__allocate(__n * sizeof(_Tp)));}
+    _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type) _NOEXCEPT
+        {_VSTD::__deallocate((void*)__p);}
+    _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
+        {return size_type(~0) / sizeof(_Tp);}
+#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+    template <class _Up, class... _Args>
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        construct(_Up* __p, _Args&&... __args)
+        {
+            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
+        }
+#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        construct(pointer __p)
+        {
+            ::new((void*)__p) _Tp();
+        }
+# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+
+    template <class _A0>
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        construct(pointer __p, _A0& __a0)
+        {
+            ::new((void*)__p) _Tp(__a0);
+        }
+    template <class _A0>
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        construct(pointer __p, const _A0& __a0)
+        {
+            ::new((void*)__p) _Tp(__a0);
+        }
+# endif  // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+    template <class _A0, class _A1>
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        construct(pointer __p, _A0& __a0, _A1& __a1)
+        {
+            ::new((void*)__p) _Tp(__a0, __a1);
+        }
+    template <class _A0, class _A1>
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        construct(pointer __p, const _A0& __a0, _A1& __a1)
+        {
+            ::new((void*)__p) _Tp(__a0, __a1);
+        }
+    template <class _A0, class _A1>
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        construct(pointer __p, _A0& __a0, const _A1& __a1)
+        {
+            ::new((void*)__p) _Tp(__a0, __a1);
+        }
+    template <class _A0, class _A1>
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        construct(pointer __p, const _A0& __a0, const _A1& __a1)
+        {
+            ::new((void*)__p) _Tp(__a0, __a1);
+        }
+#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
+    _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
+};
+
+template <class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+bool operator==(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return true;}
+
+template <class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+bool operator!=(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return false;}
+
+template <class _OutputIterator, class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY raw_storage_iterator
+    : public iterator<output_iterator_tag,
+                      _Tp,                                         // purposefully not C++03
+                      ptrdiff_t,                                   // purposefully not C++03
+                      _Tp*,                                        // purposefully not C++03
+                      raw_storage_iterator<_OutputIterator, _Tp>&> // purposefully not C++03
+{
+private:
+    _OutputIterator __x_;
+public:
+    _LIBCPP_INLINE_VISIBILITY explicit raw_storage_iterator(_OutputIterator __x) : __x_(__x) {}
+    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator*() {return *this;}
+    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(const _Tp& __element)
+        {::new(&*__x_) _Tp(__element); return *this;}
+    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator++() {++__x_; return *this;}
+    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator  operator++(int)
+        {raw_storage_iterator __t(*this); ++__x_; return __t;}
+#if _LIBCPP_STD_VER >= 14
+    _LIBCPP_INLINE_VISIBILITY _OutputIterator base() const { return __x_; } 
+#endif
+};
+
+template <class _Tp>
+pair<_Tp*, ptrdiff_t>
+get_temporary_buffer(ptrdiff_t __n) _NOEXCEPT
+{
+    pair<_Tp*, ptrdiff_t> __r(0, 0);
+    const ptrdiff_t __m = (~ptrdiff_t(0) ^
+                           ptrdiff_t(ptrdiff_t(1) << (sizeof(ptrdiff_t) * __CHAR_BIT__ - 1)))
+                           / sizeof(_Tp);
+    if (__n > __m)
+        __n = __m;
+    while (__n > 0)
+    {
+        __r.first = static_cast<_Tp*>(::operator new(__n * sizeof(_Tp), nothrow));
+        if (__r.first)
+        {
+            __r.second = __n;
+            break;
+        }
+        __n /= 2;
+    }
+    return __r;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void return_temporary_buffer(_Tp* __p) _NOEXCEPT {::operator delete(__p);}
+
+template <class _Tp>
+struct auto_ptr_ref
+{
+    _Tp* __ptr_;
+};
+
+template<class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY auto_ptr
+{
+private:
+    _Tp* __ptr_;
+public:
+    typedef _Tp element_type;
+
+    _LIBCPP_INLINE_VISIBILITY explicit auto_ptr(_Tp* __p = 0) throw() : __ptr_(__p) {}
+    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr& __p) throw() : __ptr_(__p.release()) {}
+    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr<_Up>& __p) throw()
+        : __ptr_(__p.release()) {}
+    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr& __p) throw()
+        {reset(__p.release()); return *this;}
+    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr<_Up>& __p) throw()
+        {reset(__p.release()); return *this;}
+    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr_ref<_Tp> __p) throw()
+        {reset(__p.__ptr_); return *this;}
+    _LIBCPP_INLINE_VISIBILITY ~auto_ptr() throw() {delete __ptr_;}
+
+    _LIBCPP_INLINE_VISIBILITY _Tp& operator*() const throw()
+        {return *__ptr_;}
+    _LIBCPP_INLINE_VISIBILITY _Tp* operator->() const throw() {return __ptr_;}
+    _LIBCPP_INLINE_VISIBILITY _Tp* get() const throw() {return __ptr_;}
+    _LIBCPP_INLINE_VISIBILITY _Tp* release() throw()
+    {
+        _Tp* __t = __ptr_;
+        __ptr_ = 0;
+        return __t;
+    }
+    _LIBCPP_INLINE_VISIBILITY void reset(_Tp* __p = 0) throw()
+    {
+        if (__ptr_ != __p)
+            delete __ptr_;
+        __ptr_ = __p;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr_ref<_Tp> __p) throw() : __ptr_(__p.__ptr_) {}
+    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr_ref<_Up>() throw()
+        {auto_ptr_ref<_Up> __t; __t.__ptr_ = release(); return __t;}
+    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr<_Up>() throw()
+        {return auto_ptr<_Up>(release());}
+};
+
+template <>
+class _LIBCPP_TYPE_VIS_ONLY auto_ptr<void>
+{
+public:
+    typedef void element_type;
+};
+
+template <class _T1, class _T2, bool = is_same<typename remove_cv<_T1>::type,
+                                                     typename remove_cv<_T2>::type>::value,
+                                bool = is_empty<_T1>::value
+                                       && !__libcpp_is_final<_T1>::value,
+                                bool = is_empty<_T2>::value
+                                       && !__libcpp_is_final<_T2>::value
+         >
+struct __libcpp_compressed_pair_switch;
+
+template <class _T1, class _T2, bool IsSame>
+struct __libcpp_compressed_pair_switch<_T1, _T2, IsSame, false, false> {enum {value = 0};};
+
+template <class _T1, class _T2, bool IsSame>
+struct __libcpp_compressed_pair_switch<_T1, _T2, IsSame, true, false>  {enum {value = 1};};
+
+template <class _T1, class _T2, bool IsSame>
+struct __libcpp_compressed_pair_switch<_T1, _T2, IsSame, false, true>  {enum {value = 2};};
+
+template <class _T1, class _T2>
+struct __libcpp_compressed_pair_switch<_T1, _T2, false, true, true>    {enum {value = 3};};
+
+template <class _T1, class _T2>
+struct __libcpp_compressed_pair_switch<_T1, _T2, true, true, true>     {enum {value = 1};};
+
+template <class _T1, class _T2, unsigned = __libcpp_compressed_pair_switch<_T1, _T2>::value>
+class __libcpp_compressed_pair_imp;
+
+template <class _T1, class _T2>
+class __libcpp_compressed_pair_imp<_T1, _T2, 0>
+{
+private:
+    _T1 __first_;
+    _T2 __second_;
+public:
+    typedef _T1 _T1_param;
+    typedef _T2 _T2_param;
+
+    typedef typename remove_reference<_T1>::type& _T1_reference;
+    typedef typename remove_reference<_T2>::type& _T2_reference;
+
+    typedef const typename remove_reference<_T1>::type& _T1_const_reference;
+    typedef const typename remove_reference<_T2>::type& _T2_const_reference;
+
+    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp() : __first_(), __second_() {}
+    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T1_param __t1)
+        : __first_(_VSTD::forward<_T1_param>(__t1)), __second_() {}
+    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T2_param __t2)
+        : __first_(), __second_(_VSTD::forward<_T2_param>(__t2)) {}
+    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp(_T1_param __t1, _T2_param __t2)
+        : __first_(_VSTD::forward<_T1_param>(__t1)), __second_(_VSTD::forward<_T2_param>(__t2)) {}
+
+#if defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+
+    _LIBCPP_INLINE_VISIBILITY
+    __libcpp_compressed_pair_imp(const __libcpp_compressed_pair_imp& __p)
+        _NOEXCEPT_(is_nothrow_copy_constructible<_T1>::value &&
+                   is_nothrow_copy_constructible<_T2>::value)
+        : __first_(__p.first()),
+          __second_(__p.second()) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __libcpp_compressed_pair_imp& operator=(const __libcpp_compressed_pair_imp& __p)
+        _NOEXCEPT_(is_nothrow_copy_assignable<_T1>::value &&
+                   is_nothrow_copy_assignable<_T2>::value)
+        {
+            __first_ = __p.first();
+            __second_ = __p.second();
+            return *this;
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __libcpp_compressed_pair_imp(__libcpp_compressed_pair_imp&& __p)
+        _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
+                   is_nothrow_move_constructible<_T2>::value)
+        : __first_(_VSTD::forward<_T1>(__p.first())),
+          __second_(_VSTD::forward<_T2>(__p.second())) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __libcpp_compressed_pair_imp& operator=(__libcpp_compressed_pair_imp&& __p)
+        _NOEXCEPT_(is_nothrow_move_assignable<_T1>::value &&
+                   is_nothrow_move_assignable<_T2>::value)
+        {
+            __first_ = _VSTD::forward<_T1>(__p.first());
+            __second_ = _VSTD::forward<_T2>(__p.second());
+            return *this;
+        }
+
+#endif  // defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+    template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
+        _LIBCPP_INLINE_VISIBILITY
+        __libcpp_compressed_pair_imp(piecewise_construct_t __pc,
+                                     tuple<_Args1...> __first_args,
+                                     tuple<_Args2...> __second_args,
+                                     __tuple_indices<_I1...>,
+                                     __tuple_indices<_I2...>)
+            : __first_(_VSTD::forward<_Args1>(_VSTD::get<_I1>(__first_args))...),
+              __second_(_VSTD::forward<_Args2>(_VSTD::get<_I2>(__second_args))...)
+            {}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+    _LIBCPP_INLINE_VISIBILITY _T1_reference       first() _NOEXCEPT       {return __first_;}
+    _LIBCPP_INLINE_VISIBILITY _T1_const_reference first() const _NOEXCEPT {return __first_;}
+
+    _LIBCPP_INLINE_VISIBILITY _T2_reference       second() _NOEXCEPT       {return __second_;}
+    _LIBCPP_INLINE_VISIBILITY _T2_const_reference second() const _NOEXCEPT {return __second_;}
+
+    _LIBCPP_INLINE_VISIBILITY void swap(__libcpp_compressed_pair_imp& __x)
+        _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
+                   __is_nothrow_swappable<_T2>::value)
+    {
+        using _VSTD::swap;
+        swap(__first_, __x.__first_);
+        swap(__second_, __x.__second_);
+    }
+};
+
+template <class _T1, class _T2>
+class __libcpp_compressed_pair_imp<_T1, _T2, 1>
+    : private _T1
+{
+private:
+    _T2 __second_;
+public:
+    typedef _T1 _T1_param;
+    typedef _T2 _T2_param;
+
+    typedef _T1&                                        _T1_reference;
+    typedef typename remove_reference<_T2>::type& _T2_reference;
+
+    typedef const _T1&                                        _T1_const_reference;
+    typedef const typename remove_reference<_T2>::type& _T2_const_reference;
+
+    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp() : __second_() {}
+    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T1_param __t1)
+        : _T1(_VSTD::forward<_T1_param>(__t1)), __second_() {}
+    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T2_param __t2)
+        : __second_(_VSTD::forward<_T2_param>(__t2)) {}
+    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp(_T1_param __t1, _T2_param __t2)
+        : _T1(_VSTD::forward<_T1_param>(__t1)), __second_(_VSTD::forward<_T2_param>(__t2)) {}
+
+#if defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+
+    _LIBCPP_INLINE_VISIBILITY
+    __libcpp_compressed_pair_imp(const __libcpp_compressed_pair_imp& __p)
+        _NOEXCEPT_(is_nothrow_copy_constructible<_T1>::value &&
+                   is_nothrow_copy_constructible<_T2>::value)
+        : _T1(__p.first()), __second_(__p.second()) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __libcpp_compressed_pair_imp& operator=(const __libcpp_compressed_pair_imp& __p)
+        _NOEXCEPT_(is_nothrow_copy_assignable<_T1>::value &&
+                   is_nothrow_copy_assignable<_T2>::value)
+        {
+            _T1::operator=(__p.first());
+            __second_ = __p.second();
+            return *this;
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __libcpp_compressed_pair_imp(__libcpp_compressed_pair_imp&& __p)
+        _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
+                   is_nothrow_move_constructible<_T2>::value)
+        : _T1(_VSTD::move(__p.first())), __second_(_VSTD::forward<_T2>(__p.second())) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __libcpp_compressed_pair_imp& operator=(__libcpp_compressed_pair_imp&& __p)
+        _NOEXCEPT_(is_nothrow_move_assignable<_T1>::value &&
+                   is_nothrow_move_assignable<_T2>::value)
+        {
+            _T1::operator=(_VSTD::move(__p.first()));
+            __second_ = _VSTD::forward<_T2>(__p.second());
+            return *this;
+        }
+
+#endif  // defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+    template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
+        _LIBCPP_INLINE_VISIBILITY
+        __libcpp_compressed_pair_imp(piecewise_construct_t __pc,
+                                     tuple<_Args1...> __first_args,
+                                     tuple<_Args2...> __second_args,
+                                     __tuple_indices<_I1...>,
+                                     __tuple_indices<_I2...>)
+            : _T1(_VSTD::forward<_Args1>(_VSTD::get<_I1>(__first_args))...),
+              __second_(_VSTD::forward<_Args2>(_VSTD::get<_I2>(__second_args))...)
+            {}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+    _LIBCPP_INLINE_VISIBILITY _T1_reference       first() _NOEXCEPT       {return *this;}
+    _LIBCPP_INLINE_VISIBILITY _T1_const_reference first() const _NOEXCEPT {return *this;}
+
+    _LIBCPP_INLINE_VISIBILITY _T2_reference       second() _NOEXCEPT       {return __second_;}
+    _LIBCPP_INLINE_VISIBILITY _T2_const_reference second() const _NOEXCEPT {return __second_;}
+
+    _LIBCPP_INLINE_VISIBILITY void swap(__libcpp_compressed_pair_imp& __x)
+        _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
+                   __is_nothrow_swappable<_T2>::value)
+    {
+        using _VSTD::swap;
+        swap(__second_, __x.__second_);
+    }
+};
+
+template <class _T1, class _T2>
+class __libcpp_compressed_pair_imp<_T1, _T2, 2>
+    : private _T2
+{
+private:
+    _T1 __first_;
+public:
+    typedef _T1 _T1_param;
+    typedef _T2 _T2_param;
+
+    typedef typename remove_reference<_T1>::type& _T1_reference;
+    typedef _T2&                                        _T2_reference;
+
+    typedef const typename remove_reference<_T1>::type& _T1_const_reference;
+    typedef const _T2&                                        _T2_const_reference;
+
+    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp() : __first_() {}
+    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T1_param __t1)
+        : __first_(_VSTD::forward<_T1_param>(__t1)) {}
+    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T2_param __t2)
+        : _T2(_VSTD::forward<_T2_param>(__t2)), __first_() {}
+    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp(_T1_param __t1, _T2_param __t2)
+        _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
+                   is_nothrow_move_constructible<_T2>::value)
+        : _T2(_VSTD::forward<_T2_param>(__t2)), __first_(_VSTD::forward<_T1_param>(__t1)) {}
+
+#if defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+
+    _LIBCPP_INLINE_VISIBILITY
+    __libcpp_compressed_pair_imp(const __libcpp_compressed_pair_imp& __p)
+        _NOEXCEPT_(is_nothrow_copy_constructible<_T1>::value &&
+                   is_nothrow_copy_constructible<_T2>::value)
+        : _T2(__p.second()), __first_(__p.first()) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __libcpp_compressed_pair_imp& operator=(const __libcpp_compressed_pair_imp& __p)
+        _NOEXCEPT_(is_nothrow_copy_assignable<_T1>::value &&
+                   is_nothrow_copy_assignable<_T2>::value)
+        {
+            _T2::operator=(__p.second());
+            __first_ = __p.first();
+            return *this;
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __libcpp_compressed_pair_imp(__libcpp_compressed_pair_imp&& __p)
+        _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
+                   is_nothrow_move_constructible<_T2>::value)
+        : _T2(_VSTD::forward<_T2>(__p.second())), __first_(_VSTD::move(__p.first())) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __libcpp_compressed_pair_imp& operator=(__libcpp_compressed_pair_imp&& __p)
+        _NOEXCEPT_(is_nothrow_move_assignable<_T1>::value &&
+                   is_nothrow_move_assignable<_T2>::value)
+        {
+            _T2::operator=(_VSTD::forward<_T2>(__p.second()));
+            __first_ = _VSTD::move(__p.first());
+            return *this;
+        }
+
+#endif  // defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+    template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
+        _LIBCPP_INLINE_VISIBILITY
+        __libcpp_compressed_pair_imp(piecewise_construct_t __pc,
+                                     tuple<_Args1...> __first_args,
+                                     tuple<_Args2...> __second_args,
+                                     __tuple_indices<_I1...>,
+                                     __tuple_indices<_I2...>)
+            : _T2(_VSTD::forward<_Args2>(_VSTD::get<_I2>(__second_args))...),
+              __first_(_VSTD::forward<_Args1>(_VSTD::get<_I1>(__first_args))...)
+              
+            {}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+    _LIBCPP_INLINE_VISIBILITY _T1_reference       first() _NOEXCEPT       {return __first_;}
+    _LIBCPP_INLINE_VISIBILITY _T1_const_reference first() const _NOEXCEPT {return __first_;}
+
+    _LIBCPP_INLINE_VISIBILITY _T2_reference       second() _NOEXCEPT       {return *this;}
+    _LIBCPP_INLINE_VISIBILITY _T2_const_reference second() const _NOEXCEPT {return *this;}
+
+    _LIBCPP_INLINE_VISIBILITY void swap(__libcpp_compressed_pair_imp& __x)
+        _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
+                   __is_nothrow_swappable<_T2>::value)
+    {
+        using _VSTD::swap;
+        swap(__first_, __x.__first_);
+    }
+};
+
+template <class _T1, class _T2>
+class __libcpp_compressed_pair_imp<_T1, _T2, 3>
+    : private _T1,
+      private _T2
+{
+public:
+    typedef _T1 _T1_param;
+    typedef _T2 _T2_param;
+
+    typedef _T1& _T1_reference;
+    typedef _T2& _T2_reference;
+
+    typedef const _T1& _T1_const_reference;
+    typedef const _T2& _T2_const_reference;
+
+    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp() {}
+    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T1_param __t1)
+        : _T1(_VSTD::forward<_T1_param>(__t1)) {}
+    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T2_param __t2)
+        : _T2(_VSTD::forward<_T2_param>(__t2)) {}
+    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp(_T1_param __t1, _T2_param __t2)
+        : _T1(_VSTD::forward<_T1_param>(__t1)), _T2(_VSTD::forward<_T2_param>(__t2)) {}
+
+#if defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+
+    _LIBCPP_INLINE_VISIBILITY
+    __libcpp_compressed_pair_imp(const __libcpp_compressed_pair_imp& __p)
+        _NOEXCEPT_(is_nothrow_copy_constructible<_T1>::value &&
+                   is_nothrow_copy_constructible<_T2>::value)
+        : _T1(__p.first()), _T2(__p.second()) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __libcpp_compressed_pair_imp& operator=(const __libcpp_compressed_pair_imp& __p)
+        _NOEXCEPT_(is_nothrow_copy_assignable<_T1>::value &&
+                   is_nothrow_copy_assignable<_T2>::value)
+        {
+            _T1::operator=(__p.first());
+            _T2::operator=(__p.second());
+            return *this;
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __libcpp_compressed_pair_imp(__libcpp_compressed_pair_imp&& __p)
+        _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
+                   is_nothrow_move_constructible<_T2>::value)
+        : _T1(_VSTD::move(__p.first())), _T2(_VSTD::move(__p.second())) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __libcpp_compressed_pair_imp& operator=(__libcpp_compressed_pair_imp&& __p)
+        _NOEXCEPT_(is_nothrow_move_assignable<_T1>::value &&
+                   is_nothrow_move_assignable<_T2>::value)
+        {
+            _T1::operator=(_VSTD::move(__p.first()));
+            _T2::operator=(_VSTD::move(__p.second()));
+            return *this;
+        }
+
+#endif  // defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+    template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
+        _LIBCPP_INLINE_VISIBILITY
+        __libcpp_compressed_pair_imp(piecewise_construct_t __pc,
+                                     tuple<_Args1...> __first_args,
+                                     tuple<_Args2...> __second_args,
+                                     __tuple_indices<_I1...>,
+                                     __tuple_indices<_I2...>)
+            : _T1(_VSTD::forward<_Args1>(_VSTD::get<_I1>(__first_args))...),
+              _T2(_VSTD::forward<_Args2>(_VSTD::get<_I2>(__second_args))...)
+            {}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+    _LIBCPP_INLINE_VISIBILITY _T1_reference       first() _NOEXCEPT       {return *this;}
+    _LIBCPP_INLINE_VISIBILITY _T1_const_reference first() const _NOEXCEPT {return *this;}
+
+    _LIBCPP_INLINE_VISIBILITY _T2_reference       second() _NOEXCEPT       {return *this;}
+    _LIBCPP_INLINE_VISIBILITY _T2_const_reference second() const _NOEXCEPT {return *this;}
+
+    _LIBCPP_INLINE_VISIBILITY void swap(__libcpp_compressed_pair_imp&)
+        _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
+                   __is_nothrow_swappable<_T2>::value)
+    {
+    }
+};
+
+template <class _T1, class _T2>
+class __compressed_pair
+    : private __libcpp_compressed_pair_imp<_T1, _T2>
+{
+    typedef __libcpp_compressed_pair_imp<_T1, _T2> base;
+public:
+    typedef typename base::_T1_param _T1_param;
+    typedef typename base::_T2_param _T2_param;
+
+    typedef typename base::_T1_reference _T1_reference;
+    typedef typename base::_T2_reference _T2_reference;
+
+    typedef typename base::_T1_const_reference _T1_const_reference;
+    typedef typename base::_T2_const_reference _T2_const_reference;
+
+    _LIBCPP_INLINE_VISIBILITY __compressed_pair() {}
+    _LIBCPP_INLINE_VISIBILITY explicit __compressed_pair(_T1_param __t1)
+        : base(_VSTD::forward<_T1_param>(__t1)) {}
+    _LIBCPP_INLINE_VISIBILITY explicit __compressed_pair(_T2_param __t2)
+        : base(_VSTD::forward<_T2_param>(__t2)) {}
+    _LIBCPP_INLINE_VISIBILITY __compressed_pair(_T1_param __t1, _T2_param __t2)
+        : base(_VSTD::forward<_T1_param>(__t1), _VSTD::forward<_T2_param>(__t2)) {}
+
+#if defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+
+    _LIBCPP_INLINE_VISIBILITY
+    __compressed_pair(const __compressed_pair& __p)
+        _NOEXCEPT_(is_nothrow_copy_constructible<_T1>::value &&
+                   is_nothrow_copy_constructible<_T2>::value)
+        : base(__p) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __compressed_pair& operator=(const __compressed_pair& __p)
+        _NOEXCEPT_(is_nothrow_copy_assignable<_T1>::value &&
+                   is_nothrow_copy_assignable<_T2>::value)
+        {
+            base::operator=(__p);
+            return *this;
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __compressed_pair(__compressed_pair&& __p)
+        _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
+                   is_nothrow_move_constructible<_T2>::value)
+        : base(_VSTD::move(__p)) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    __compressed_pair& operator=(__compressed_pair&& __p)
+        _NOEXCEPT_(is_nothrow_move_assignable<_T1>::value &&
+                   is_nothrow_move_assignable<_T2>::value)
+        {
+            base::operator=(_VSTD::move(__p));
+            return *this;
+        }
+
+#endif  // defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+    template <class... _Args1, class... _Args2>
+        _LIBCPP_INLINE_VISIBILITY
+        __compressed_pair(piecewise_construct_t __pc, tuple<_Args1...> __first_args,
+                                                      tuple<_Args2...> __second_args)
+            : base(__pc, _VSTD::move(__first_args), _VSTD::move(__second_args),
+                   typename __make_tuple_indices<sizeof...(_Args1)>::type(),
+                   typename __make_tuple_indices<sizeof...(_Args2) >::type())
+            {}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+    _LIBCPP_INLINE_VISIBILITY _T1_reference       first() _NOEXCEPT       {return base::first();}
+    _LIBCPP_INLINE_VISIBILITY _T1_const_reference first() const _NOEXCEPT {return base::first();}
+
+    _LIBCPP_INLINE_VISIBILITY _T2_reference       second() _NOEXCEPT       {return base::second();}
+    _LIBCPP_INLINE_VISIBILITY _T2_const_reference second() const _NOEXCEPT {return base::second();}
+
+    _LIBCPP_INLINE_VISIBILITY void swap(__compressed_pair& __x)
+        _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
+                   __is_nothrow_swappable<_T2>::value)
+        {base::swap(__x);}
+};
+
+template <class _T1, class _T2>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(__compressed_pair<_T1, _T2>& __x, __compressed_pair<_T1, _T2>& __y)
+        _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
+                   __is_nothrow_swappable<_T2>::value)
+    {__x.swap(__y);}
+
+// __same_or_less_cv_qualified
+
+template <class _Ptr1, class _Ptr2,
+          bool = is_same<typename remove_cv<typename pointer_traits<_Ptr1>::element_type>::type,
+                         typename remove_cv<typename pointer_traits<_Ptr2>::element_type>::type
+                        >::value
+         >
+struct __same_or_less_cv_qualified_imp
+    : is_convertible<_Ptr1, _Ptr2> {};
+
+template <class _Ptr1, class _Ptr2>
+struct __same_or_less_cv_qualified_imp<_Ptr1, _Ptr2, false>
+    : false_type {};
+
+template <class _Ptr1, class _Ptr2, bool = is_pointer<_Ptr1>::value ||
+                                           is_same<_Ptr1, _Ptr2>::value ||
+                                           __has_element_type<_Ptr1>::value>
+struct __same_or_less_cv_qualified
+    : __same_or_less_cv_qualified_imp<_Ptr1, _Ptr2> {};
+
+template <class _Ptr1, class _Ptr2>
+struct __same_or_less_cv_qualified<_Ptr1, _Ptr2, false>
+    : false_type {};
+
+// default_delete
+
+template <class _Tp>
+struct _LIBCPP_TYPE_VIS_ONLY default_delete
+{
+#ifndef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR default_delete() _NOEXCEPT = default;
+#else
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR default_delete() _NOEXCEPT {}
+#endif
+    template <class _Up>
+        _LIBCPP_INLINE_VISIBILITY default_delete(const default_delete<_Up>&,
+             typename enable_if<is_convertible<_Up*, _Tp*>::value>::type* = 0) _NOEXCEPT {}
+    _LIBCPP_INLINE_VISIBILITY void operator() (_Tp* __ptr) const _NOEXCEPT
+        {
+            static_assert(sizeof(_Tp) > 0, "default_delete can not delete incomplete type");
+            static_assert(!is_void<_Tp>::value, "default_delete can not delete incomplete type");
+            delete __ptr;
+        }
+};
+
+template <class _Tp>
+struct _LIBCPP_TYPE_VIS_ONLY default_delete<_Tp[]>
+{
+public:
+#ifndef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR default_delete() _NOEXCEPT = default;
+#else
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR default_delete() _NOEXCEPT {}
+#endif
+    template <class _Up>
+        _LIBCPP_INLINE_VISIBILITY default_delete(const default_delete<_Up[]>&,
+             typename enable_if<__same_or_less_cv_qualified<_Up*, _Tp*>::value>::type* = 0) _NOEXCEPT {}
+    template <class _Up>
+        _LIBCPP_INLINE_VISIBILITY
+        void operator() (_Up* __ptr,
+                         typename enable_if<__same_or_less_cv_qualified<_Up*, _Tp*>::value>::type* = 0) const _NOEXCEPT
+        {
+            static_assert(sizeof(_Tp) > 0, "default_delete can not delete incomplete type");
+            static_assert(!is_void<_Tp>::value, "default_delete can not delete incomplete type");
+            delete [] __ptr;
+        }
+};
+
+template <class _Tp, class _Dp = default_delete<_Tp> >
+class _LIBCPP_TYPE_VIS_ONLY unique_ptr
+{
+public:
+    typedef _Tp element_type;
+    typedef _Dp deleter_type;
+    typedef typename __pointer_type<_Tp, deleter_type>::type pointer;
+private:
+    __compressed_pair<pointer, deleter_type> __ptr_;
+
+#ifdef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    unique_ptr(unique_ptr&);
+    template <class _Up, class _Ep>
+        unique_ptr(unique_ptr<_Up, _Ep>&);
+    unique_ptr& operator=(unique_ptr&);
+    template <class _Up, class _Ep>
+        unique_ptr& operator=(unique_ptr<_Up, _Ep>&);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    struct __nat {int __for_bool_;};
+
+    typedef       typename remove_reference<deleter_type>::type& _Dp_reference;
+    typedef const typename remove_reference<deleter_type>::type& _Dp_const_reference;
+public:
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR unique_ptr() _NOEXCEPT
+        : __ptr_(pointer())
+        {
+            static_assert(!is_pointer<deleter_type>::value,
+                "unique_ptr constructed with null function pointer deleter");
+        }
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT
+        : __ptr_(pointer())
+        {
+            static_assert(!is_pointer<deleter_type>::value,
+                "unique_ptr constructed with null function pointer deleter");
+        }
+    _LIBCPP_INLINE_VISIBILITY explicit unique_ptr(pointer __p) _NOEXCEPT
+        : __ptr_(_VSTD::move(__p))
+        {
+            static_assert(!is_pointer<deleter_type>::value,
+                "unique_ptr constructed with null function pointer deleter");
+        }
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY unique_ptr(pointer __p, typename conditional<
+                                        is_reference<deleter_type>::value,
+                                        deleter_type,
+                                        typename add_lvalue_reference<const deleter_type>::type>::type __d)
+             _NOEXCEPT
+        : __ptr_(__p, __d) {}
+
+    _LIBCPP_INLINE_VISIBILITY unique_ptr(pointer __p, typename remove_reference<deleter_type>::type&& __d)
+             _NOEXCEPT
+        : __ptr_(__p, _VSTD::move(__d))
+        {
+            static_assert(!is_reference<deleter_type>::value, "rvalue deleter bound to reference");
+        }
+    _LIBCPP_INLINE_VISIBILITY unique_ptr(unique_ptr&& __u) _NOEXCEPT
+        : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {}
+    template <class _Up, class _Ep>
+        _LIBCPP_INLINE_VISIBILITY
+        unique_ptr(unique_ptr<_Up, _Ep>&& __u,
+                   typename enable_if
+                      <
+                        !is_array<_Up>::value &&
+                         is_convertible<typename unique_ptr<_Up, _Ep>::pointer, pointer>::value &&
+                         is_convertible<_Ep, deleter_type>::value &&
+                         (
+                            !is_reference<deleter_type>::value ||
+                            is_same<deleter_type, _Ep>::value
+                         ),
+                         __nat
+                      >::type = __nat()) _NOEXCEPT
+            : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {}
+
+    template <class _Up>
+        _LIBCPP_INLINE_VISIBILITY unique_ptr(auto_ptr<_Up>&& __p,
+                typename enable_if<
+                                      is_convertible<_Up*, _Tp*>::value &&
+                                      is_same<_Dp, default_delete<_Tp> >::value,
+                                      __nat
+                                  >::type = __nat()) _NOEXCEPT
+            : __ptr_(__p.release())
+            {
+            }
+
+        _LIBCPP_INLINE_VISIBILITY unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT
+            {
+                reset(__u.release());
+                __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
+                return *this;
+            }
+
+        template <class _Up, class _Ep>
+            _LIBCPP_INLINE_VISIBILITY
+            typename enable_if
+            <
+                !is_array<_Up>::value &&
+                is_convertible<typename unique_ptr<_Up, _Ep>::pointer, pointer>::value &&
+                is_assignable<deleter_type&, _Ep&&>::value,
+                unique_ptr&
+            >::type
+            operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
+            {
+                reset(__u.release());
+                __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
+                return *this;
+            }
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY operator __rv<unique_ptr>()
+    {
+        return __rv<unique_ptr>(*this);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY unique_ptr(__rv<unique_ptr> __u)
+        : __ptr_(__u->release(), _VSTD::forward<deleter_type>(__u->get_deleter())) {}
+
+    template <class _Up, class _Ep>
+    _LIBCPP_INLINE_VISIBILITY unique_ptr& operator=(unique_ptr<_Up, _Ep> __u)
+    {
+        reset(__u.release());
+        __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY unique_ptr(pointer __p, deleter_type __d)
+        : __ptr_(_VSTD::move(__p), _VSTD::move(__d)) {}
+
+    template <class _Up>
+        _LIBCPP_INLINE_VISIBILITY
+                typename enable_if<
+                                      is_convertible<_Up*, _Tp*>::value &&
+                                      is_same<_Dp, default_delete<_Tp> >::value,
+                                      unique_ptr&
+                                  >::type
+        operator=(auto_ptr<_Up> __p)
+            {reset(__p.release()); return *this;}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY ~unique_ptr() {reset();}
+
+    _LIBCPP_INLINE_VISIBILITY unique_ptr& operator=(nullptr_t) _NOEXCEPT
+    {
+        reset();
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY typename add_lvalue_reference<_Tp>::type operator*() const
+        {return *__ptr_.first();}
+    _LIBCPP_INLINE_VISIBILITY pointer operator->() const _NOEXCEPT {return __ptr_.first();}
+    _LIBCPP_INLINE_VISIBILITY pointer get() const _NOEXCEPT {return __ptr_.first();}
+    _LIBCPP_INLINE_VISIBILITY       _Dp_reference get_deleter() _NOEXCEPT
+        {return __ptr_.second();}
+    _LIBCPP_INLINE_VISIBILITY _Dp_const_reference get_deleter() const _NOEXCEPT
+        {return __ptr_.second();}
+    _LIBCPP_INLINE_VISIBILITY
+        _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT
+        {return __ptr_.first() != nullptr;}
+
+    _LIBCPP_INLINE_VISIBILITY pointer release() _NOEXCEPT
+    {
+        pointer __t = __ptr_.first();
+        __ptr_.first() = pointer();
+        return __t;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY void reset(pointer __p = pointer()) _NOEXCEPT
+    {
+        pointer __tmp = __ptr_.first();
+        __ptr_.first() = __p;
+        if (__tmp)
+            __ptr_.second()(__tmp);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY void swap(unique_ptr& __u) _NOEXCEPT
+        {__ptr_.swap(__u.__ptr_);}
+};
+
+template <class _Tp, class _Dp>
+class _LIBCPP_TYPE_VIS_ONLY unique_ptr<_Tp[], _Dp>
+{
+public:
+    typedef _Tp element_type;
+    typedef _Dp deleter_type;
+    typedef typename __pointer_type<_Tp, deleter_type>::type pointer;
+private:
+    __compressed_pair<pointer, deleter_type> __ptr_;
+
+#ifdef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    unique_ptr(unique_ptr&);
+    template <class _Up>
+        unique_ptr(unique_ptr<_Up>&);
+    unique_ptr& operator=(unique_ptr&);
+    template <class _Up>
+        unique_ptr& operator=(unique_ptr<_Up>&);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    struct __nat {int __for_bool_;};
+
+    typedef       typename remove_reference<deleter_type>::type& _Dp_reference;
+    typedef const typename remove_reference<deleter_type>::type& _Dp_const_reference;
+public:
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR unique_ptr() _NOEXCEPT
+        : __ptr_(pointer())
+        {
+            static_assert(!is_pointer<deleter_type>::value,
+                "unique_ptr constructed with null function pointer deleter");
+        }
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT
+        : __ptr_(pointer())
+        {
+            static_assert(!is_pointer<deleter_type>::value,
+                "unique_ptr constructed with null function pointer deleter");
+        }
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template <class _Pp>
+    _LIBCPP_INLINE_VISIBILITY explicit unique_ptr(_Pp __p,
+            typename enable_if<__same_or_less_cv_qualified<_Pp, pointer>::value, __nat>::type = __nat()) _NOEXCEPT
+        : __ptr_(__p)
+        {
+            static_assert(!is_pointer<deleter_type>::value,
+                "unique_ptr constructed with null function pointer deleter");
+        }
+
+    template <class _Pp>
+    _LIBCPP_INLINE_VISIBILITY unique_ptr(_Pp __p, typename conditional<
+                                       is_reference<deleter_type>::value,
+                                       deleter_type,
+                                       typename add_lvalue_reference<const deleter_type>::type>::type __d,
+                                       typename enable_if<__same_or_less_cv_qualified<_Pp, pointer>::value, __nat>::type = __nat())
+             _NOEXCEPT
+        : __ptr_(__p, __d) {}
+
+    _LIBCPP_INLINE_VISIBILITY unique_ptr(nullptr_t, typename conditional<
+                                       is_reference<deleter_type>::value,
+                                       deleter_type,
+                                       typename add_lvalue_reference<const deleter_type>::type>::type __d)
+             _NOEXCEPT
+        : __ptr_(pointer(), __d) {}
+
+    template <class _Pp>
+    _LIBCPP_INLINE_VISIBILITY unique_ptr(_Pp __p,
+                                         typename remove_reference<deleter_type>::type&& __d,
+                                         typename enable_if<__same_or_less_cv_qualified<_Pp, pointer>::value, __nat>::type = __nat())
+             _NOEXCEPT
+        : __ptr_(__p, _VSTD::move(__d))
+        {
+            static_assert(!is_reference<deleter_type>::value, "rvalue deleter bound to reference");
+        }
+
+    _LIBCPP_INLINE_VISIBILITY unique_ptr(nullptr_t, typename remove_reference<deleter_type>::type&& __d)
+             _NOEXCEPT
+        : __ptr_(pointer(), _VSTD::move(__d))
+        {
+            static_assert(!is_reference<deleter_type>::value, "rvalue deleter bound to reference");
+        }
+
+    _LIBCPP_INLINE_VISIBILITY unique_ptr(unique_ptr&& __u) _NOEXCEPT
+        : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {}
+
+    _LIBCPP_INLINE_VISIBILITY unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT
+        {
+            reset(__u.release());
+            __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
+            return *this;
+        }
+
+    template <class _Up, class _Ep>
+        _LIBCPP_INLINE_VISIBILITY
+        unique_ptr(unique_ptr<_Up, _Ep>&& __u,
+                   typename enable_if
+                            <
+                                is_array<_Up>::value &&
+                                __same_or_less_cv_qualified<typename unique_ptr<_Up, _Ep>::pointer, pointer>::value
+                                && is_convertible<_Ep, deleter_type>::value &&
+                                (
+                                    !is_reference<deleter_type>::value ||
+                                    is_same<deleter_type, _Ep>::value
+                                ),
+                                __nat
+                            >::type = __nat()
+                  ) _NOEXCEPT
+        : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {}
+
+
+        template <class _Up, class _Ep>
+            _LIBCPP_INLINE_VISIBILITY
+            typename enable_if
+            <
+                is_array<_Up>::value &&
+                __same_or_less_cv_qualified<typename unique_ptr<_Up, _Ep>::pointer, pointer>::value &&
+                is_assignable<deleter_type&, _Ep&&>::value,
+                unique_ptr&
+            >::type
+            operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
+            {
+                reset(__u.release());
+                __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
+                return *this;
+            }
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY explicit unique_ptr(pointer __p)
+        : __ptr_(__p)
+        {
+            static_assert(!is_pointer<deleter_type>::value,
+                "unique_ptr constructed with null function pointer deleter");
+        }
+
+    _LIBCPP_INLINE_VISIBILITY unique_ptr(pointer __p, deleter_type __d)
+        : __ptr_(__p, _VSTD::forward<deleter_type>(__d)) {}
+
+    _LIBCPP_INLINE_VISIBILITY unique_ptr(nullptr_t, deleter_type __d)
+        : __ptr_(pointer(), _VSTD::forward<deleter_type>(__d)) {}
+
+    _LIBCPP_INLINE_VISIBILITY operator __rv<unique_ptr>()
+    {
+        return __rv<unique_ptr>(*this);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY unique_ptr(__rv<unique_ptr> __u)
+        : __ptr_(__u->release(), _VSTD::forward<deleter_type>(__u->get_deleter())) {}
+
+    _LIBCPP_INLINE_VISIBILITY unique_ptr& operator=(__rv<unique_ptr> __u)
+    {
+        reset(__u->release());
+        __ptr_.second() = _VSTD::forward<deleter_type>(__u->get_deleter());
+        return *this;
+    }
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY ~unique_ptr() {reset();}
+
+    _LIBCPP_INLINE_VISIBILITY unique_ptr& operator=(nullptr_t) _NOEXCEPT
+    {
+        reset();
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY typename add_lvalue_reference<_Tp>::type operator[](size_t __i) const
+        {return __ptr_.first()[__i];}
+    _LIBCPP_INLINE_VISIBILITY pointer get() const _NOEXCEPT {return __ptr_.first();}
+    _LIBCPP_INLINE_VISIBILITY       _Dp_reference get_deleter() _NOEXCEPT
+        {return __ptr_.second();}
+    _LIBCPP_INLINE_VISIBILITY _Dp_const_reference get_deleter() const _NOEXCEPT
+        {return __ptr_.second();}
+    _LIBCPP_INLINE_VISIBILITY
+        _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT
+        {return __ptr_.first() != nullptr;}
+
+    _LIBCPP_INLINE_VISIBILITY pointer release() _NOEXCEPT
+    {
+        pointer __t = __ptr_.first();
+        __ptr_.first() = pointer();
+        return __t;
+    }
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template <class _Pp>
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<__same_or_less_cv_qualified<_Pp, pointer>::value, void>::type
+    reset(_Pp __p) _NOEXCEPT
+    {
+        pointer __tmp = __ptr_.first();
+        __ptr_.first() = __p;
+        if (__tmp)
+            __ptr_.second()(__tmp);
+    }
+    _LIBCPP_INLINE_VISIBILITY void reset(nullptr_t) _NOEXCEPT
+    {
+        pointer __tmp = __ptr_.first();
+        __ptr_.first() = nullptr;
+        if (__tmp)
+            __ptr_.second()(__tmp);
+    }
+    _LIBCPP_INLINE_VISIBILITY void reset() _NOEXCEPT
+    {
+        pointer __tmp = __ptr_.first();
+        __ptr_.first() = nullptr;
+        if (__tmp)
+            __ptr_.second()(__tmp);
+    }
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY void reset(pointer __p = pointer())
+    {
+        pointer __tmp = __ptr_.first();
+        __ptr_.first() = __p;
+        if (__tmp)
+            __ptr_.second()(__tmp);
+    }
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY void swap(unique_ptr& __u) {__ptr_.swap(__u.__ptr_);}
+private:
+
+#ifdef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template <class _Up>
+        explicit unique_ptr(_Up);
+    template <class _Up>
+        unique_ptr(_Up __u,
+                   typename conditional<
+                                       is_reference<deleter_type>::value,
+                                       deleter_type,
+                                       typename add_lvalue_reference<const deleter_type>::type>::type,
+                   typename enable_if
+                      <
+                         is_convertible<_Up, pointer>::value,
+                         __nat
+                      >::type = __nat());
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+};
+
+template <class _Tp, class _Dp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(unique_ptr<_Tp, _Dp>& __x, unique_ptr<_Tp, _Dp>& __y) _NOEXCEPT {__x.swap(__y);}
+
+template <class _T1, class _D1, class _T2, class _D2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __x.get() == __y.get();}
+
+template <class _T1, class _D1, class _T2, class _D2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x == __y);}
+
+template <class _T1, class _D1, class _T2, class _D2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator< (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y)
+{
+    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
+    typedef typename unique_ptr<_T2, _D2>::pointer _P2;
+    typedef typename common_type<_P1, _P2>::type _Vp;
+    return less<_Vp>()(__x.get(), __y.get());
+}
+
+template <class _T1, class _D1, class _T2, class _D2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator> (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __y < __x;}
+
+template <class _T1, class _D1, class _T2, class _D2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__y < __x);}
+
+template <class _T1, class _D1, class _T2, class _D2>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x < __y);}
+
+template <class _T1, class _D1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
+{
+    return !__x;
+}
+
+template <class _T1, class _D1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
+{
+    return !__x;
+}
+
+template <class _T1, class _D1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
+{
+    return static_cast<bool>(__x);
+}
+
+template <class _T1, class _D1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
+{
+    return static_cast<bool>(__x);
+}
+
+template <class _T1, class _D1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<(const unique_ptr<_T1, _D1>& __x, nullptr_t)
+{
+    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
+    return less<_P1>()(__x.get(), nullptr);
+}
+
+template <class _T1, class _D1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<(nullptr_t, const unique_ptr<_T1, _D1>& __x)
+{
+    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
+    return less<_P1>()(nullptr, __x.get());
+}
+
+template <class _T1, class _D1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>(const unique_ptr<_T1, _D1>& __x, nullptr_t)
+{
+    return nullptr < __x;
+}
+
+template <class _T1, class _D1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>(nullptr_t, const unique_ptr<_T1, _D1>& __x)
+{
+    return __x < nullptr;
+}
+
+template <class _T1, class _D1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
+{
+    return !(nullptr < __x);
+}
+
+template <class _T1, class _D1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
+{
+    return !(__x < nullptr);
+}
+
+template <class _T1, class _D1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
+{
+    return !(__x < nullptr);
+}
+
+template <class _T1, class _D1>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
+{
+    return !(nullptr < __x);
+}
+
+#ifdef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Dp>
+inline _LIBCPP_INLINE_VISIBILITY
+unique_ptr<_Tp, _Dp>
+move(unique_ptr<_Tp, _Dp>& __t)
+{
+    return unique_ptr<_Tp, _Dp>(__rv<unique_ptr<_Tp, _Dp> >(__t));
+}
+
+#endif
+
+#if _LIBCPP_STD_VER > 11
+
+template<class _Tp>
+struct __unique_if
+{
+    typedef unique_ptr<_Tp> __unique_single;
+};
+
+template<class _Tp>
+struct __unique_if<_Tp[]>
+{
+    typedef unique_ptr<_Tp[]> __unique_array_unknown_bound;
+};
+
+template<class _Tp, size_t _Np>
+struct __unique_if<_Tp[_Np]>
+{
+    typedef void __unique_array_known_bound;
+};
+
+template<class _Tp, class... _Args>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __unique_if<_Tp>::__unique_single
+make_unique(_Args&&... __args)
+{
+    return unique_ptr<_Tp>(new _Tp(_VSTD::forward<_Args>(__args)...));
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename __unique_if<_Tp>::__unique_array_unknown_bound
+make_unique(size_t __n)
+{
+    typedef typename remove_extent<_Tp>::type _Up;
+    return unique_ptr<_Tp>(new _Up[__n]());
+}
+
+template<class _Tp, class... _Args>
+    typename __unique_if<_Tp>::__unique_array_known_bound
+    make_unique(_Args&&...) = delete;
+
+#endif  // _LIBCPP_STD_VER > 11
+
+template <class _Tp> struct hash;
+
+template <class _Size>
+inline _LIBCPP_INLINE_VISIBILITY
+_Size
+__loadword(const void* __p)
+{
+    _Size __r;
+    std::memcpy(&__r, __p, sizeof(__r));
+    return __r;
+}
+
+// We use murmur2 when size_t is 32 bits, and cityhash64 when size_t
+// is 64 bits.  This is because cityhash64 uses 64bit x 64bit
+// multiplication, which can be very slow on 32-bit systems.
+template <class _Size, size_t = sizeof(_Size)*__CHAR_BIT__>
+struct __murmur2_or_cityhash;
+
+template <class _Size>
+struct __murmur2_or_cityhash<_Size, 32>
+{
+    _Size operator()(const void* __key, _Size __len);
+};
+
+// murmur2
+template <class _Size>
+_Size
+__murmur2_or_cityhash<_Size, 32>::operator()(const void* __key, _Size __len)
+{
+    const _Size __m = 0x5bd1e995;
+    const _Size __r = 24;
+    _Size __h = __len;
+    const unsigned char* __data = static_cast<const unsigned char*>(__key);
+    for (; __len >= 4; __data += 4, __len -= 4)
+    {
+        _Size __k = __loadword<_Size>(__data);
+        __k *= __m;
+        __k ^= __k >> __r;
+        __k *= __m;
+        __h *= __m;
+        __h ^= __k;
+    }
+    switch (__len)
+    {
+    case 3:
+        __h ^= __data[2] << 16;
+    case 2:
+        __h ^= __data[1] << 8;
+    case 1:
+        __h ^= __data[0];
+        __h *= __m;
+    }
+    __h ^= __h >> 13;
+    __h *= __m;
+    __h ^= __h >> 15;
+    return __h;
+}
+
+template <class _Size>
+struct __murmur2_or_cityhash<_Size, 64>
+{
+    _Size operator()(const void* __key, _Size __len);
+
+ private:
+  // Some primes between 2^63 and 2^64.
+  static const _Size __k0 = 0xc3a5c85c97cb3127ULL;
+  static const _Size __k1 = 0xb492b66fbe98f273ULL;
+  static const _Size __k2 = 0x9ae16a3b2f90404fULL;
+  static const _Size __k3 = 0xc949d7c7509e6557ULL;
+
+  static _Size __rotate(_Size __val, int __shift) {
+    return __shift == 0 ? __val : ((__val >> __shift) | (__val << (64 - __shift)));
+  }
+
+  static _Size __rotate_by_at_least_1(_Size __val, int __shift) {
+    return (__val >> __shift) | (__val << (64 - __shift));
+  }
+
+  static _Size __shift_mix(_Size __val) {
+    return __val ^ (__val >> 47);
+  }
+
+  static _Size __hash_len_16(_Size __u, _Size __v) {
+    const _Size __mul = 0x9ddfea08eb382d69ULL;
+    _Size __a = (__u ^ __v) * __mul;
+    __a ^= (__a >> 47);
+    _Size __b = (__v ^ __a) * __mul;
+    __b ^= (__b >> 47);
+    __b *= __mul;
+    return __b;
+  }
+
+  static _Size __hash_len_0_to_16(const char* __s, _Size __len) {
+    if (__len > 8) {
+      const _Size __a = __loadword<_Size>(__s);
+      const _Size __b = __loadword<_Size>(__s + __len - 8);
+      return __hash_len_16(__a, __rotate_by_at_least_1(__b + __len, __len)) ^ __b;
+    }
+    if (__len >= 4) {
+      const uint32_t __a = __loadword<uint32_t>(__s);
+      const uint32_t __b = __loadword<uint32_t>(__s + __len - 4);
+      return __hash_len_16(__len + (__a << 3), __b);
+    }
+    if (__len > 0) {
+      const unsigned char __a = __s[0];
+      const unsigned char __b = __s[__len >> 1];
+      const unsigned char __c = __s[__len - 1];
+      const uint32_t __y = static_cast<uint32_t>(__a) +
+                           (static_cast<uint32_t>(__b) << 8);
+      const uint32_t __z = __len + (static_cast<uint32_t>(__c) << 2);
+      return __shift_mix(__y * __k2 ^ __z * __k3) * __k2;
+    }
+    return __k2;
+  }
+
+  static _Size __hash_len_17_to_32(const char *__s, _Size __len) {
+    const _Size __a = __loadword<_Size>(__s) * __k1;
+    const _Size __b = __loadword<_Size>(__s + 8);
+    const _Size __c = __loadword<_Size>(__s + __len - 8) * __k2;
+    const _Size __d = __loadword<_Size>(__s + __len - 16) * __k0;
+    return __hash_len_16(__rotate(__a - __b, 43) + __rotate(__c, 30) + __d,
+                         __a + __rotate(__b ^ __k3, 20) - __c + __len);
+  }
+
+  // Return a 16-byte hash for 48 bytes.  Quick and dirty.
+  // Callers do best to use "random-looking" values for a and b.
+  static pair<_Size, _Size> __weak_hash_len_32_with_seeds(
+      _Size __w, _Size __x, _Size __y, _Size __z, _Size __a, _Size __b) {
+    __a += __w;
+    __b = __rotate(__b + __a + __z, 21);
+    const _Size __c = __a;
+    __a += __x;
+    __a += __y;
+    __b += __rotate(__a, 44);
+    return pair<_Size, _Size>(__a + __z, __b + __c);
+  }
+
+  // Return a 16-byte hash for s[0] ... s[31], a, and b.  Quick and dirty.
+  static pair<_Size, _Size> __weak_hash_len_32_with_seeds(
+      const char* __s, _Size __a, _Size __b) {
+    return __weak_hash_len_32_with_seeds(__loadword<_Size>(__s),
+                                         __loadword<_Size>(__s + 8),
+                                         __loadword<_Size>(__s + 16),
+                                         __loadword<_Size>(__s + 24),
+                                         __a,
+                                         __b);
+  }
+
+  // Return an 8-byte hash for 33 to 64 bytes.
+  static _Size __hash_len_33_to_64(const char *__s, size_t __len) {
+    _Size __z = __loadword<_Size>(__s + 24);
+    _Size __a = __loadword<_Size>(__s) +
+                (__len + __loadword<_Size>(__s + __len - 16)) * __k0;
+    _Size __b = __rotate(__a + __z, 52);
+    _Size __c = __rotate(__a, 37);
+    __a += __loadword<_Size>(__s + 8);
+    __c += __rotate(__a, 7);
+    __a += __loadword<_Size>(__s + 16);
+    _Size __vf = __a + __z;
+    _Size __vs = __b + __rotate(__a, 31) + __c;
+    __a = __loadword<_Size>(__s + 16) + __loadword<_Size>(__s + __len - 32);
+    __z += __loadword<_Size>(__s + __len - 8);
+    __b = __rotate(__a + __z, 52);
+    __c = __rotate(__a, 37);
+    __a += __loadword<_Size>(__s + __len - 24);
+    __c += __rotate(__a, 7);
+    __a += __loadword<_Size>(__s + __len - 16);
+    _Size __wf = __a + __z;
+    _Size __ws = __b + __rotate(__a, 31) + __c;
+    _Size __r = __shift_mix((__vf + __ws) * __k2 + (__wf + __vs) * __k0);
+    return __shift_mix(__r * __k0 + __vs) * __k2;
+  }
+};
+
+// cityhash64
+template <class _Size>
+_Size
+__murmur2_or_cityhash<_Size, 64>::operator()(const void* __key, _Size __len)
+{
+  const char* __s = static_cast<const char*>(__key);
+  if (__len <= 32) {
+    if (__len <= 16) {
+      return __hash_len_0_to_16(__s, __len);
+    } else {
+      return __hash_len_17_to_32(__s, __len);
+    }
+  } else if (__len <= 64) {
+    return __hash_len_33_to_64(__s, __len);
+  }
+
+  // For strings over 64 bytes we hash the end first, and then as we
+  // loop we keep 56 bytes of state: v, w, x, y, and z.
+  _Size __x = __loadword<_Size>(__s + __len - 40);
+  _Size __y = __loadword<_Size>(__s + __len - 16) +
+              __loadword<_Size>(__s + __len - 56);
+  _Size __z = __hash_len_16(__loadword<_Size>(__s + __len - 48) + __len,
+                          __loadword<_Size>(__s + __len - 24));
+  pair<_Size, _Size> __v = __weak_hash_len_32_with_seeds(__s + __len - 64, __len, __z);
+  pair<_Size, _Size> __w = __weak_hash_len_32_with_seeds(__s + __len - 32, __y + __k1, __x);
+  __x = __x * __k1 + __loadword<_Size>(__s);
+
+  // Decrease len to the nearest multiple of 64, and operate on 64-byte chunks.
+  __len = (__len - 1) & ~static_cast<_Size>(63);
+  do {
+    __x = __rotate(__x + __y + __v.first + __loadword<_Size>(__s + 8), 37) * __k1;
+    __y = __rotate(__y + __v.second + __loadword<_Size>(__s + 48), 42) * __k1;
+    __x ^= __w.second;
+    __y += __v.first + __loadword<_Size>(__s + 40);
+    __z = __rotate(__z + __w.first, 33) * __k1;
+    __v = __weak_hash_len_32_with_seeds(__s, __v.second * __k1, __x + __w.first);
+    __w = __weak_hash_len_32_with_seeds(__s + 32, __z + __w.second,
+                                        __y + __loadword<_Size>(__s + 16));
+    std::swap(__z, __x);
+    __s += 64;
+    __len -= 64;
+  } while (__len != 0);
+  return __hash_len_16(
+      __hash_len_16(__v.first, __w.first) + __shift_mix(__y) * __k1 + __z,
+      __hash_len_16(__v.second, __w.second) + __x);
+}
+
+template <class _Tp, size_t = sizeof(_Tp) / sizeof(size_t)>
+struct __scalar_hash;
+
+template <class _Tp>
+struct __scalar_hash<_Tp, 0>
+    : public unary_function<_Tp, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(_Tp __v) const _NOEXCEPT
+    {
+        union
+        {
+            _Tp    __t;
+            size_t __a;
+        } __u;
+        __u.__a = 0;
+        __u.__t = __v;
+        return __u.__a;
+    }
+};
+
+template <class _Tp>
+struct __scalar_hash<_Tp, 1>
+    : public unary_function<_Tp, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(_Tp __v) const _NOEXCEPT
+    {
+        union
+        {
+            _Tp    __t;
+            size_t __a;
+        } __u;
+        __u.__t = __v;
+        return __u.__a;
+    }
+};
+
+template <class _Tp>
+struct __scalar_hash<_Tp, 2>
+    : public unary_function<_Tp, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(_Tp __v) const _NOEXCEPT
+    {
+        union
+        {
+            _Tp __t;
+            struct
+            {
+                size_t __a;
+                size_t __b;
+            } __s;
+        } __u;
+        __u.__t = __v;
+        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
+    }
+};
+
+template <class _Tp>
+struct __scalar_hash<_Tp, 3>
+    : public unary_function<_Tp, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(_Tp __v) const _NOEXCEPT
+    {
+        union
+        {
+            _Tp __t;
+            struct
+            {
+                size_t __a;
+                size_t __b;
+                size_t __c;
+            } __s;
+        } __u;
+        __u.__t = __v;
+        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
+    }
+};
+
+template <class _Tp>
+struct __scalar_hash<_Tp, 4>
+    : public unary_function<_Tp, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(_Tp __v) const _NOEXCEPT
+    {
+        union
+        {
+            _Tp __t;
+            struct
+            {
+                size_t __a;
+                size_t __b;
+                size_t __c;
+                size_t __d;
+            } __s;
+        } __u;
+        __u.__t = __v;
+        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
+    }
+};
+
+template<class _Tp>
+struct _LIBCPP_TYPE_VIS_ONLY hash<_Tp*>
+    : public unary_function<_Tp*, size_t>
+{
+    _LIBCPP_INLINE_VISIBILITY
+    size_t operator()(_Tp* __v) const _NOEXCEPT
+    {
+        union
+        {
+            _Tp* __t;
+            size_t __a;
+        } __u;
+        __u.__t = __v;
+        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
+    }
+};
+
+template <class _Tp, class _Dp>
+struct _LIBCPP_TYPE_VIS_ONLY hash<unique_ptr<_Tp, _Dp> >
+{
+    typedef unique_ptr<_Tp, _Dp> argument_type;
+    typedef size_t               result_type;
+    _LIBCPP_INLINE_VISIBILITY
+    result_type operator()(const argument_type& __ptr) const _NOEXCEPT
+    {
+        typedef typename argument_type::pointer pointer;
+        return hash<pointer>()(__ptr.get());
+    }
+};
+
+struct __destruct_n
+{
+private:
+    size_t size;
+
+    template <class _Tp>
+    _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
+        {for (size_t __i = 0; __i < size; ++__i, ++__p) __p->~_Tp();}
+
+    template <class _Tp>
+    _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
+        {}
+
+    _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
+        {++size;}
+    _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
+        {}
+
+    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
+        {size = __s;}
+    _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
+        {}
+public:
+    _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
+        : size(__s) {}
+
+    template <class _Tp>
+    _LIBCPP_INLINE_VISIBILITY void __incr(_Tp*) _NOEXCEPT
+        {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
+
+    template <class _Tp>
+    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
+        {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
+
+    template <class _Tp>
+    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
+        {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
+};
+
+template <class _Alloc>
+class __allocator_destructor
+{
+    typedef allocator_traits<_Alloc> __alloc_traits;
+public:
+    typedef typename __alloc_traits::pointer pointer;
+    typedef typename __alloc_traits::size_type size_type;
+private:
+    _Alloc& __alloc_;
+    size_type __s_;
+public:
+    _LIBCPP_INLINE_VISIBILITY __allocator_destructor(_Alloc& __a, size_type __s)
+             _NOEXCEPT
+        : __alloc_(__a), __s_(__s) {}
+    _LIBCPP_INLINE_VISIBILITY
+    void operator()(pointer __p) _NOEXCEPT
+        {__alloc_traits::deallocate(__alloc_, __p, __s_);}
+};
+
+template <class _InputIterator, class _ForwardIterator>
+_ForwardIterator
+uninitialized_copy(_InputIterator __f, _InputIterator __l, _ForwardIterator __r)
+{
+    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    _ForwardIterator __s = __r;
+    try
+    {
+#endif
+        for (; __f != __l; ++__f, (void) ++__r)
+            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        for (; __s != __r; ++__s)
+            __s->~value_type();
+        throw;
+    }
+#endif
+    return __r;
+}
+
+template <class _InputIterator, class _Size, class _ForwardIterator>
+_ForwardIterator
+uninitialized_copy_n(_InputIterator __f, _Size __n, _ForwardIterator __r)
+{
+    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    _ForwardIterator __s = __r;
+    try
+    {
+#endif
+        for (; __n > 0; ++__f, (void) ++__r, (void) --__n)
+            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        for (; __s != __r; ++__s)
+            __s->~value_type();
+        throw;
+    }
+#endif
+    return __r;
+}
+
+template <class _ForwardIterator, class _Tp>
+void
+uninitialized_fill(_ForwardIterator __f, _ForwardIterator __l, const _Tp& __x)
+{
+    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    _ForwardIterator __s = __f;
+    try
+    {
+#endif
+        for (; __f != __l; ++__f)
+            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        for (; __s != __f; ++__s)
+            __s->~value_type();
+        throw;
+    }
+#endif
+}
+
+template <class _ForwardIterator, class _Size, class _Tp>
+_ForwardIterator
+uninitialized_fill_n(_ForwardIterator __f, _Size __n, const _Tp& __x)
+{
+    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    _ForwardIterator __s = __f;
+    try
+    {
+#endif
+        for (; __n > 0; ++__f, (void) --__n)
+            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        for (; __s != __f; ++__s)
+            __s->~value_type();
+        throw;
+    }
+#endif
+    return __f;
+}
+
+class _LIBCPP_EXCEPTION_ABI bad_weak_ptr
+    : public std::exception
+{
+public:
+    virtual ~bad_weak_ptr() _NOEXCEPT;
+    virtual const char* what() const  _NOEXCEPT;
+};
+
+template<class _Tp> class _LIBCPP_TYPE_VIS_ONLY weak_ptr;
+
+class _LIBCPP_TYPE_VIS __shared_count
+{
+    __shared_count(const __shared_count&);
+    __shared_count& operator=(const __shared_count&);
+
+protected:
+    long __shared_owners_;
+    virtual ~__shared_count();
+private:
+    virtual void __on_zero_shared() _NOEXCEPT = 0;
+
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __shared_count(long __refs = 0) _NOEXCEPT
+        : __shared_owners_(__refs) {}
+
+    void __add_shared() _NOEXCEPT;
+    bool __release_shared() _NOEXCEPT;
+    _LIBCPP_INLINE_VISIBILITY
+    long use_count() const _NOEXCEPT {
+        return __libcpp_relaxed_load(&__shared_owners_) + 1;
+    }
+};
+
+class _LIBCPP_TYPE_VIS __shared_weak_count
+    : private __shared_count
+{
+    long __shared_weak_owners_;
+
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __shared_weak_count(long __refs = 0) _NOEXCEPT
+        : __shared_count(__refs),
+          __shared_weak_owners_(__refs) {}
+protected:
+    virtual ~__shared_weak_count();
+
+public:
+    void __add_shared() _NOEXCEPT;
+    void __add_weak() _NOEXCEPT;
+    void __release_shared() _NOEXCEPT;
+    void __release_weak() _NOEXCEPT;
+    _LIBCPP_INLINE_VISIBILITY
+    long use_count() const _NOEXCEPT {return __shared_count::use_count();}
+    __shared_weak_count* lock() _NOEXCEPT;
+
+    // Define the function out only if we build static libc++ without RTTI.
+    // Otherwise we may break clients who need to compile their projects with
+    // -fno-rtti and yet link against a libc++.dylib compiled
+    // without -fno-rtti.
+#if !defined(_LIBCPP_NO_RTTI) || !defined(_LIBCPP_BUILD_STATIC)
+    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
+#endif
+private:
+    virtual void __on_zero_shared_weak() _NOEXCEPT = 0;
+};
+
+template <class _Tp, class _Dp, class _Alloc>
+class __shared_ptr_pointer
+    : public __shared_weak_count
+{
+    __compressed_pair<__compressed_pair<_Tp, _Dp>, _Alloc> __data_;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    __shared_ptr_pointer(_Tp __p, _Dp __d, _Alloc __a)
+        :  __data_(__compressed_pair<_Tp, _Dp>(__p, _VSTD::move(__d)), _VSTD::move(__a)) {}
+
+#ifndef _LIBCPP_NO_RTTI
+    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
+#endif
+
+private:
+    virtual void __on_zero_shared() _NOEXCEPT;
+    virtual void __on_zero_shared_weak() _NOEXCEPT;
+};
+
+#ifndef _LIBCPP_NO_RTTI
+
+template <class _Tp, class _Dp, class _Alloc>
+const void*
+__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__get_deleter(const type_info& __t) const _NOEXCEPT
+{
+    return __t == typeid(_Dp) ? _VSTD::addressof(__data_.first().second()) : 0;
+}
+
+#endif  // _LIBCPP_NO_RTTI
+
+template <class _Tp, class _Dp, class _Alloc>
+void
+__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared() _NOEXCEPT
+{
+    __data_.first().second()(__data_.first().first());
+    __data_.first().second().~_Dp();
+}
+
+template <class _Tp, class _Dp, class _Alloc>
+void
+__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
+{
+    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_pointer>::type _Al;
+    typedef allocator_traits<_Al> _ATraits;
+    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
+
+    _Al __a(__data_.second());
+    __data_.second().~_Alloc();
+    __a.deallocate(_PTraits::pointer_to(*this), 1);
+}
+
+template <class _Tp, class _Alloc>
+class __shared_ptr_emplace
+    : public __shared_weak_count
+{
+    __compressed_pair<_Alloc, _Tp> __data_;
+public:
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+    _LIBCPP_INLINE_VISIBILITY
+    __shared_ptr_emplace(_Alloc __a)
+        :  __data_(_VSTD::move(__a)) {}
+
+    template <class ..._Args>
+        _LIBCPP_INLINE_VISIBILITY
+        __shared_ptr_emplace(_Alloc __a, _Args&& ...__args)
+            :  __data_(piecewise_construct, _VSTD::forward_as_tuple(__a),
+                   _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)) {}
+
+#else  // _LIBCPP_HAS_NO_VARIADICS
+
+    _LIBCPP_INLINE_VISIBILITY
+    __shared_ptr_emplace(_Alloc __a)
+        :  __data_(__a) {}
+
+    template <class _A0>
+        _LIBCPP_INLINE_VISIBILITY
+        __shared_ptr_emplace(_Alloc __a, _A0& __a0)
+            :  __data_(__a, _Tp(__a0)) {}
+
+    template <class _A0, class _A1>
+        _LIBCPP_INLINE_VISIBILITY
+        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1)
+            :  __data_(__a, _Tp(__a0, __a1)) {}
+
+    template <class _A0, class _A1, class _A2>
+        _LIBCPP_INLINE_VISIBILITY
+        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1, _A2& __a2)
+            :  __data_(__a, _Tp(__a0, __a1, __a2)) {}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+private:
+    virtual void __on_zero_shared() _NOEXCEPT;
+    virtual void __on_zero_shared_weak() _NOEXCEPT;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    _Tp* get() _NOEXCEPT {return &__data_.second();}
+};
+
+template <class _Tp, class _Alloc>
+void
+__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared() _NOEXCEPT
+{
+    __data_.second().~_Tp();
+}
+
+template <class _Tp, class _Alloc>
+void
+__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
+{
+    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_emplace>::type _Al;
+    typedef allocator_traits<_Al> _ATraits;
+    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
+    _Al __a(__data_.first());
+    __data_.first().~_Alloc();
+    __a.deallocate(_PTraits::pointer_to(*this), 1);
+}
+
+template<class _Tp> class _LIBCPP_TYPE_VIS_ONLY enable_shared_from_this;
+
+template<class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY shared_ptr
+{
+public:
+    typedef _Tp element_type;
+private:
+    element_type*      __ptr_;
+    __shared_weak_count* __cntrl_;
+
+    struct __nat {int __for_bool_;};
+public:
+    _LIBCPP_CONSTEXPR shared_ptr() _NOEXCEPT;
+    _LIBCPP_CONSTEXPR shared_ptr(nullptr_t) _NOEXCEPT;
+    template<class _Yp>
+        explicit shared_ptr(_Yp* __p,
+                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
+    template<class _Yp, class _Dp>
+        shared_ptr(_Yp* __p, _Dp __d,
+                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
+    template<class _Yp, class _Dp, class _Alloc>
+        shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
+                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
+    template <class _Dp> shared_ptr(nullptr_t __p, _Dp __d);
+    template <class _Dp, class _Alloc> shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a);
+    template<class _Yp> shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) _NOEXCEPT;
+    shared_ptr(const shared_ptr& __r) _NOEXCEPT;
+    template<class _Yp>
+        shared_ptr(const shared_ptr<_Yp>& __r,
+                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat>::type = __nat())
+                       _NOEXCEPT;
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    shared_ptr(shared_ptr&& __r) _NOEXCEPT;
+    template<class _Yp> shared_ptr(shared_ptr<_Yp>&& __r,
+                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat>::type = __nat())
+                       _NOEXCEPT;
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template<class _Yp> explicit shared_ptr(const weak_ptr<_Yp>& __r,
+                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat>::type= __nat());
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template<class _Yp>
+        shared_ptr(auto_ptr<_Yp>&& __r,
+                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
+#else
+    template<class _Yp>
+        shared_ptr(auto_ptr<_Yp> __r,
+                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
+#endif
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template <class _Yp, class _Dp>
+        shared_ptr(unique_ptr<_Yp, _Dp>&&,
+                   typename enable_if
+                   <
+                       !is_lvalue_reference<_Dp>::value &&
+                       !is_array<_Yp>::value &&
+                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
+                       __nat
+                   >::type = __nat());
+    template <class _Yp, class _Dp>
+        shared_ptr(unique_ptr<_Yp, _Dp>&&,
+                   typename enable_if
+                   <
+                       is_lvalue_reference<_Dp>::value &&
+                       !is_array<_Yp>::value &&
+                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
+                       __nat
+                   >::type = __nat());
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template <class _Yp, class _Dp>
+        shared_ptr(unique_ptr<_Yp, _Dp>,
+                   typename enable_if
+                   <
+                       !is_lvalue_reference<_Dp>::value &&
+                       !is_array<_Yp>::value &&
+                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
+                       __nat
+                   >::type = __nat());
+    template <class _Yp, class _Dp>
+        shared_ptr(unique_ptr<_Yp, _Dp>,
+                   typename enable_if
+                   <
+                       is_lvalue_reference<_Dp>::value &&
+                       !is_array<_Yp>::value &&
+                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
+                       __nat
+                   >::type = __nat());
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    ~shared_ptr();
+
+    shared_ptr& operator=(const shared_ptr& __r) _NOEXCEPT;
+    template<class _Yp>
+        typename enable_if
+        <
+            is_convertible<_Yp*, element_type*>::value,
+            shared_ptr&
+        >::type
+        operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT;
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    shared_ptr& operator=(shared_ptr&& __r) _NOEXCEPT;
+    template<class _Yp>
+        typename enable_if
+        <
+            is_convertible<_Yp*, element_type*>::value,
+            shared_ptr<_Tp>&
+        >::type
+        operator=(shared_ptr<_Yp>&& __r);
+    template<class _Yp>
+        typename enable_if
+        <
+            !is_array<_Yp>::value &&
+            is_convertible<_Yp*, element_type*>::value,
+            shared_ptr
+        >::type&
+        operator=(auto_ptr<_Yp>&& __r);
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template<class _Yp>
+        typename enable_if
+        <
+            !is_array<_Yp>::value &&
+            is_convertible<_Yp*, element_type*>::value,
+            shared_ptr&
+        >::type
+        operator=(auto_ptr<_Yp> __r);
+#endif
+    template <class _Yp, class _Dp>
+        typename enable_if
+        <
+            !is_array<_Yp>::value &&
+            is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
+            shared_ptr&
+        >::type
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+        operator=(unique_ptr<_Yp, _Dp>&& __r);
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+        operator=(unique_ptr<_Yp, _Dp> __r);
+#endif
+
+    void swap(shared_ptr& __r) _NOEXCEPT;
+    void reset() _NOEXCEPT;
+    template<class _Yp>
+        typename enable_if
+        <
+            is_convertible<_Yp*, element_type*>::value,
+            void
+        >::type
+        reset(_Yp* __p);
+    template<class _Yp, class _Dp>
+        typename enable_if
+        <
+            is_convertible<_Yp*, element_type*>::value,
+            void
+        >::type
+        reset(_Yp* __p, _Dp __d);
+    template<class _Yp, class _Dp, class _Alloc>
+        typename enable_if
+        <
+            is_convertible<_Yp*, element_type*>::value,
+            void
+        >::type
+        reset(_Yp* __p, _Dp __d, _Alloc __a);
+
+    _LIBCPP_INLINE_VISIBILITY
+    element_type* get() const _NOEXCEPT {return __ptr_;}
+    _LIBCPP_INLINE_VISIBILITY
+    typename add_lvalue_reference<element_type>::type operator*() const _NOEXCEPT
+        {return *__ptr_;}
+    _LIBCPP_INLINE_VISIBILITY
+    element_type* operator->() const _NOEXCEPT {return __ptr_;}
+    _LIBCPP_INLINE_VISIBILITY
+    long use_count() const _NOEXCEPT {return __cntrl_ ? __cntrl_->use_count() : 0;}
+    _LIBCPP_INLINE_VISIBILITY
+    bool unique() const _NOEXCEPT {return use_count() == 1;}
+    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {return get() != 0;}
+    template <class _Up>
+        _LIBCPP_INLINE_VISIBILITY
+        bool owner_before(shared_ptr<_Up> const& __p) const
+        {return __cntrl_ < __p.__cntrl_;}
+    template <class _Up>
+        _LIBCPP_INLINE_VISIBILITY
+        bool owner_before(weak_ptr<_Up> const& __p) const
+        {return __cntrl_ < __p.__cntrl_;}
+    _LIBCPP_INLINE_VISIBILITY
+    bool
+    __owner_equivalent(const shared_ptr& __p) const
+        {return __cntrl_ == __p.__cntrl_;}
+
+#ifndef _LIBCPP_NO_RTTI
+    template <class _Dp>
+        _LIBCPP_INLINE_VISIBILITY
+        _Dp* __get_deleter() const _NOEXCEPT
+            {return (_Dp*)(__cntrl_ ? __cntrl_->__get_deleter(typeid(_Dp)) : 0);}
+#endif  // _LIBCPP_NO_RTTI
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+    template<class ..._Args>
+        static
+        shared_ptr<_Tp>
+        make_shared(_Args&& ...__args);
+
+    template<class _Alloc, class ..._Args>
+        static
+        shared_ptr<_Tp>
+        allocate_shared(const _Alloc& __a, _Args&& ...__args);
+
+#else  // _LIBCPP_HAS_NO_VARIADICS
+
+    static shared_ptr<_Tp> make_shared();
+
+    template<class _A0>
+        static shared_ptr<_Tp> make_shared(_A0&);
+
+    template<class _A0, class _A1>
+        static shared_ptr<_Tp> make_shared(_A0&, _A1&);
+
+    template<class _A0, class _A1, class _A2>
+        static shared_ptr<_Tp> make_shared(_A0&, _A1&, _A2&);
+
+    template<class _Alloc>
+        static shared_ptr<_Tp>
+        allocate_shared(const _Alloc& __a);
+
+    template<class _Alloc, class _A0>
+        static shared_ptr<_Tp>
+        allocate_shared(const _Alloc& __a, _A0& __a0);
+
+    template<class _Alloc, class _A0, class _A1>
+        static shared_ptr<_Tp>
+        allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1);
+
+    template<class _Alloc, class _A0, class _A1, class _A2>
+        static shared_ptr<_Tp>
+        allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2);
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+private:
+
+    template <class _Yp>
+        _LIBCPP_INLINE_VISIBILITY
+        void
+        __enable_weak_this(const enable_shared_from_this<_Yp>* __e) _NOEXCEPT
+        {
+            if (__e)
+            {
+                __e->__weak_this_.__ptr_ = const_cast<_Yp*>(static_cast<const _Yp*>(__e));
+                __e->__weak_this_.__cntrl_ = __cntrl_;
+                __cntrl_->__add_weak();
+            }
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __enable_weak_this(const volatile void*) _NOEXCEPT {}
+
+    template <class _Up> friend class _LIBCPP_TYPE_VIS_ONLY shared_ptr;
+    template <class _Up> friend class _LIBCPP_TYPE_VIS_ONLY weak_ptr;
+};
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+shared_ptr<_Tp>::shared_ptr() _NOEXCEPT
+    : __ptr_(0),
+      __cntrl_(0)
+{
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+shared_ptr<_Tp>::shared_ptr(nullptr_t) _NOEXCEPT
+    : __ptr_(0),
+      __cntrl_(0)
+{
+}
+
+template<class _Tp>
+template<class _Yp>
+shared_ptr<_Tp>::shared_ptr(_Yp* __p,
+                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
+    : __ptr_(__p)
+{
+    unique_ptr<_Yp> __hold(__p);
+    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<_Yp> > _CntrlBlk;
+    __cntrl_ = new _CntrlBlk(__p, default_delete<_Yp>(), allocator<_Yp>());
+    __hold.release();
+    __enable_weak_this(__p);
+}
+
+template<class _Tp>
+template<class _Yp, class _Dp>
+shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d,
+                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
+    : __ptr_(__p)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typedef __shared_ptr_pointer<_Yp*, _Dp, allocator<_Yp> > _CntrlBlk;
+        __cntrl_ = new _CntrlBlk(__p, __d, allocator<_Yp>());
+        __enable_weak_this(__p);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __d(__p);
+        throw;
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+}
+
+template<class _Tp>
+template<class _Dp>
+shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d)
+    : __ptr_(0)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typedef __shared_ptr_pointer<nullptr_t, _Dp, allocator<_Tp> > _CntrlBlk;
+        __cntrl_ = new _CntrlBlk(__p, __d, allocator<_Tp>());
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __d(__p);
+        throw;
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+}
+
+template<class _Tp>
+template<class _Yp, class _Dp, class _Alloc>
+shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
+                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
+    : __ptr_(__p)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk;
+        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
+        typedef __allocator_destructor<_A2> _D2;
+        _A2 __a2(__a);
+        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
+        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
+            _CntrlBlk(__p, __d, __a);
+        __cntrl_ = _VSTD::addressof(*__hold2.release());
+        __enable_weak_this(__p);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __d(__p);
+        throw;
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+}
+
+template<class _Tp>
+template<class _Dp, class _Alloc>
+shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a)
+    : __ptr_(0)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk;
+        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
+        typedef __allocator_destructor<_A2> _D2;
+        _A2 __a2(__a);
+        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
+        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
+            _CntrlBlk(__p, __d, __a);
+        __cntrl_ = _VSTD::addressof(*__hold2.release());
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __d(__p);
+        throw;
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+}
+
+template<class _Tp>
+template<class _Yp>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r, element_type *__p) _NOEXCEPT
+    : __ptr_(__p),
+      __cntrl_(__r.__cntrl_)
+{
+    if (__cntrl_)
+        __cntrl_->__add_shared();
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>::shared_ptr(const shared_ptr& __r) _NOEXCEPT
+    : __ptr_(__r.__ptr_),
+      __cntrl_(__r.__cntrl_)
+{
+    if (__cntrl_)
+        __cntrl_->__add_shared();
+}
+
+template<class _Tp>
+template<class _Yp>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r,
+                            typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat>::type)
+         _NOEXCEPT
+    : __ptr_(__r.__ptr_),
+      __cntrl_(__r.__cntrl_)
+{
+    if (__cntrl_)
+        __cntrl_->__add_shared();
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>::shared_ptr(shared_ptr&& __r) _NOEXCEPT
+    : __ptr_(__r.__ptr_),
+      __cntrl_(__r.__cntrl_)
+{
+    __r.__ptr_ = 0;
+    __r.__cntrl_ = 0;
+}
+
+template<class _Tp>
+template<class _Yp>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>::shared_ptr(shared_ptr<_Yp>&& __r,
+                            typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat>::type)
+         _NOEXCEPT
+    : __ptr_(__r.__ptr_),
+      __cntrl_(__r.__cntrl_)
+{
+    __r.__ptr_ = 0;
+    __r.__cntrl_ = 0;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template<class _Tp>
+template<class _Yp>
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp>&& __r,
+#else
+shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp> __r,
+#endif
+                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
+    : __ptr_(__r.get())
+{
+    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<_Yp> > _CntrlBlk;
+    __cntrl_ = new _CntrlBlk(__r.get(), default_delete<_Yp>(), allocator<_Yp>());
+    __enable_weak_this(__r.get());
+    __r.release();
+}
+
+template<class _Tp>
+template <class _Yp, class _Dp>
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
+#else
+shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp> __r,
+#endif
+                            typename enable_if
+                            <
+                                !is_lvalue_reference<_Dp>::value &&
+                                !is_array<_Yp>::value &&
+                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
+                                __nat
+                            >::type)
+    : __ptr_(__r.get())
+{
+#if _LIBCPP_STD_VER > 11
+    if (__ptr_ == nullptr)
+        __cntrl_ = nullptr;
+    else
+#endif
+    {
+        typedef __shared_ptr_pointer<_Yp*, _Dp, allocator<_Yp> > _CntrlBlk;
+        __cntrl_ = new _CntrlBlk(__r.get(), __r.get_deleter(), allocator<_Yp>());
+        __enable_weak_this(__r.get());
+    }
+    __r.release();
+}
+
+template<class _Tp>
+template <class _Yp, class _Dp>
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
+#else
+shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp> __r,
+#endif
+                            typename enable_if
+                            <
+                                is_lvalue_reference<_Dp>::value &&
+                                !is_array<_Yp>::value &&
+                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
+                                __nat
+                            >::type)
+    : __ptr_(__r.get())
+{
+#if _LIBCPP_STD_VER > 11
+    if (__ptr_ == nullptr)
+        __cntrl_ = nullptr;
+    else
+#endif
+    {
+        typedef __shared_ptr_pointer<_Yp*,
+                                     reference_wrapper<typename remove_reference<_Dp>::type>,
+                                     allocator<_Yp> > _CntrlBlk;
+        __cntrl_ = new _CntrlBlk(__r.get(), ref(__r.get_deleter()), allocator<_Yp>());
+        __enable_weak_this(__r.get());
+    }
+    __r.release();
+}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template<class _Tp>
+template<class ..._Args>
+shared_ptr<_Tp>
+shared_ptr<_Tp>::make_shared(_Args&& ...__args)
+{
+    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
+    typedef allocator<_CntrlBlk> _A2;
+    typedef __allocator_destructor<_A2> _D2;
+    _A2 __a2;
+    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
+    ::new(__hold2.get()) _CntrlBlk(__a2, _VSTD::forward<_Args>(__args)...);
+    shared_ptr<_Tp> __r;
+    __r.__ptr_ = __hold2.get()->get();
+    __r.__cntrl_ = __hold2.release();
+    __r.__enable_weak_this(__r.__ptr_);
+    return __r;
+}
+
+template<class _Tp>
+template<class _Alloc, class ..._Args>
+shared_ptr<_Tp>
+shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _Args&& ...__args)
+{
+    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
+    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
+    typedef __allocator_destructor<_A2> _D2;
+    _A2 __a2(__a);
+    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
+    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
+        _CntrlBlk(__a, _VSTD::forward<_Args>(__args)...);
+    shared_ptr<_Tp> __r;
+    __r.__ptr_ = __hold2.get()->get();
+    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
+    __r.__enable_weak_this(__r.__ptr_);
+    return __r;
+}
+
+#else  // _LIBCPP_HAS_NO_VARIADICS
+
+template<class _Tp>
+shared_ptr<_Tp>
+shared_ptr<_Tp>::make_shared()
+{
+    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
+    typedef allocator<_CntrlBlk> _Alloc2;
+    typedef __allocator_destructor<_Alloc2> _D2;
+    _Alloc2 __alloc2;
+    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
+    ::new(__hold2.get()) _CntrlBlk(__alloc2);
+    shared_ptr<_Tp> __r;
+    __r.__ptr_ = __hold2.get()->get();
+    __r.__cntrl_ = __hold2.release();
+    __r.__enable_weak_this(__r.__ptr_);
+    return __r;
+}
+
+template<class _Tp>
+template<class _A0>
+shared_ptr<_Tp>
+shared_ptr<_Tp>::make_shared(_A0& __a0)
+{
+    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
+    typedef allocator<_CntrlBlk> _Alloc2;
+    typedef __allocator_destructor<_Alloc2> _D2;
+    _Alloc2 __alloc2;
+    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
+    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0);
+    shared_ptr<_Tp> __r;
+    __r.__ptr_ = __hold2.get()->get();
+    __r.__cntrl_ = __hold2.release();
+    __r.__enable_weak_this(__r.__ptr_);
+    return __r;
+}
+
+template<class _Tp>
+template<class _A0, class _A1>
+shared_ptr<_Tp>
+shared_ptr<_Tp>::make_shared(_A0& __a0, _A1& __a1)
+{
+    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
+    typedef allocator<_CntrlBlk> _Alloc2;
+    typedef __allocator_destructor<_Alloc2> _D2;
+    _Alloc2 __alloc2;
+    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
+    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0, __a1);
+    shared_ptr<_Tp> __r;
+    __r.__ptr_ = __hold2.get()->get();
+    __r.__cntrl_ = __hold2.release();
+    __r.__enable_weak_this(__r.__ptr_);
+    return __r;
+}
+
+template<class _Tp>
+template<class _A0, class _A1, class _A2>
+shared_ptr<_Tp>
+shared_ptr<_Tp>::make_shared(_A0& __a0, _A1& __a1, _A2& __a2)
+{
+    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
+    typedef allocator<_CntrlBlk> _Alloc2;
+    typedef __allocator_destructor<_Alloc2> _D2;
+    _Alloc2 __alloc2;
+    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
+    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0, __a1, __a2);
+    shared_ptr<_Tp> __r;
+    __r.__ptr_ = __hold2.get()->get();
+    __r.__cntrl_ = __hold2.release();
+    __r.__enable_weak_this(__r.__ptr_);
+    return __r;
+}
+
+template<class _Tp>
+template<class _Alloc>
+shared_ptr<_Tp>
+shared_ptr<_Tp>::allocate_shared(const _Alloc& __a)
+{
+    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
+    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
+    typedef __allocator_destructor<_Alloc2> _D2;
+    _Alloc2 __alloc2(__a);
+    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
+    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
+        _CntrlBlk(__a);
+    shared_ptr<_Tp> __r;
+    __r.__ptr_ = __hold2.get()->get();
+    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
+    __r.__enable_weak_this(__r.__ptr_);
+    return __r;
+}
+
+template<class _Tp>
+template<class _Alloc, class _A0>
+shared_ptr<_Tp>
+shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0)
+{
+    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
+    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
+    typedef __allocator_destructor<_Alloc2> _D2;
+    _Alloc2 __alloc2(__a);
+    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
+    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
+        _CntrlBlk(__a, __a0);
+    shared_ptr<_Tp> __r;
+    __r.__ptr_ = __hold2.get()->get();
+    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
+    __r.__enable_weak_this(__r.__ptr_);
+    return __r;
+}
+
+template<class _Tp>
+template<class _Alloc, class _A0, class _A1>
+shared_ptr<_Tp>
+shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1)
+{
+    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
+    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
+    typedef __allocator_destructor<_Alloc2> _D2;
+    _Alloc2 __alloc2(__a);
+    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
+    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
+        _CntrlBlk(__a, __a0, __a1);
+    shared_ptr<_Tp> __r;
+    __r.__ptr_ = __hold2.get()->get();
+    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
+    __r.__enable_weak_this(__r.__ptr_);
+    return __r;
+}
+
+template<class _Tp>
+template<class _Alloc, class _A0, class _A1, class _A2>
+shared_ptr<_Tp>
+shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2)
+{
+    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
+    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
+    typedef __allocator_destructor<_Alloc2> _D2;
+    _Alloc2 __alloc2(__a);
+    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
+    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
+        _CntrlBlk(__a, __a0, __a1, __a2);
+    shared_ptr<_Tp> __r;
+    __r.__ptr_ = __hold2.get()->get();
+    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
+    __r.__enable_weak_this(__r.__ptr_);
+    return __r;
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+template<class _Tp>
+shared_ptr<_Tp>::~shared_ptr()
+{
+    if (__cntrl_)
+        __cntrl_->__release_shared();
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>&
+shared_ptr<_Tp>::operator=(const shared_ptr& __r) _NOEXCEPT
+{
+    shared_ptr(__r).swap(*this);
+    return *this;
+}
+
+template<class _Tp>
+template<class _Yp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_convertible<_Yp*, _Tp*>::value,
+    shared_ptr<_Tp>&
+>::type
+shared_ptr<_Tp>::operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT
+{
+    shared_ptr(__r).swap(*this);
+    return *this;
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>&
+shared_ptr<_Tp>::operator=(shared_ptr&& __r) _NOEXCEPT
+{
+    shared_ptr(_VSTD::move(__r)).swap(*this);
+    return *this;
+}
+
+template<class _Tp>
+template<class _Yp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_convertible<_Yp*, _Tp*>::value,
+    shared_ptr<_Tp>&
+>::type
+shared_ptr<_Tp>::operator=(shared_ptr<_Yp>&& __r)
+{
+    shared_ptr(_VSTD::move(__r)).swap(*this);
+    return *this;
+}
+
+template<class _Tp>
+template<class _Yp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_array<_Yp>::value &&
+    is_convertible<_Yp*, _Tp*>::value,
+    shared_ptr<_Tp>
+>::type&
+shared_ptr<_Tp>::operator=(auto_ptr<_Yp>&& __r)
+{
+    shared_ptr(_VSTD::move(__r)).swap(*this);
+    return *this;
+}
+
+template<class _Tp>
+template <class _Yp, class _Dp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_array<_Yp>::value &&
+    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, _Tp*>::value,
+    shared_ptr<_Tp>&
+>::type
+shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp>&& __r)
+{
+    shared_ptr(_VSTD::move(__r)).swap(*this);
+    return *this;
+}
+
+#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template<class _Tp>
+template<class _Yp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_array<_Yp>::value &&
+    is_convertible<_Yp*, _Tp*>::value,
+    shared_ptr<_Tp>&
+>::type
+shared_ptr<_Tp>::operator=(auto_ptr<_Yp> __r)
+{
+    shared_ptr(__r).swap(*this);
+    return *this;
+}
+
+template<class _Tp>
+template <class _Yp, class _Dp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_array<_Yp>::value &&
+    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, _Tp*>::value,
+    shared_ptr<_Tp>&
+>::type
+shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp> __r)
+{
+    shared_ptr(_VSTD::move(__r)).swap(*this);
+    return *this;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+shared_ptr<_Tp>::swap(shared_ptr& __r) _NOEXCEPT
+{
+    _VSTD::swap(__ptr_, __r.__ptr_);
+    _VSTD::swap(__cntrl_, __r.__cntrl_);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+shared_ptr<_Tp>::reset() _NOEXCEPT
+{
+    shared_ptr().swap(*this);
+}
+
+template<class _Tp>
+template<class _Yp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_convertible<_Yp*, _Tp*>::value,
+    void
+>::type
+shared_ptr<_Tp>::reset(_Yp* __p)
+{
+    shared_ptr(__p).swap(*this);
+}
+
+template<class _Tp>
+template<class _Yp, class _Dp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_convertible<_Yp*, _Tp*>::value,
+    void
+>::type
+shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d)
+{
+    shared_ptr(__p, __d).swap(*this);
+}
+
+template<class _Tp>
+template<class _Yp, class _Dp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_convertible<_Yp*, _Tp*>::value,
+    void
+>::type
+shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d, _Alloc __a)
+{
+    shared_ptr(__p, __d, __a).swap(*this);
+}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template<class _Tp, class ..._Args>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_array<_Tp>::value,
+    shared_ptr<_Tp>
+>::type
+make_shared(_Args&& ...__args)
+{
+    return shared_ptr<_Tp>::make_shared(_VSTD::forward<_Args>(__args)...);
+}
+
+template<class _Tp, class _Alloc, class ..._Args>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_array<_Tp>::value,
+    shared_ptr<_Tp>
+>::type
+allocate_shared(const _Alloc& __a, _Args&& ...__args)
+{
+    return shared_ptr<_Tp>::allocate_shared(__a, _VSTD::forward<_Args>(__args)...);
+}
+
+#else  // _LIBCPP_HAS_NO_VARIADICS
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>
+make_shared()
+{
+    return shared_ptr<_Tp>::make_shared();
+}
+
+template<class _Tp, class _A0>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>
+make_shared(_A0& __a0)
+{
+    return shared_ptr<_Tp>::make_shared(__a0);
+}
+
+template<class _Tp, class _A0, class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>
+make_shared(_A0& __a0, _A1& __a1)
+{
+    return shared_ptr<_Tp>::make_shared(__a0, __a1);
+}
+
+template<class _Tp, class _A0, class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>
+make_shared(_A0& __a0, _A1& __a1, _A2& __a2)
+{
+    return shared_ptr<_Tp>::make_shared(__a0, __a1, __a2);
+}
+
+template<class _Tp, class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>
+allocate_shared(const _Alloc& __a)
+{
+    return shared_ptr<_Tp>::allocate_shared(__a);
+}
+
+template<class _Tp, class _Alloc, class _A0>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>
+allocate_shared(const _Alloc& __a, _A0& __a0)
+{
+    return shared_ptr<_Tp>::allocate_shared(__a, __a0);
+}
+
+template<class _Tp, class _Alloc, class _A0, class _A1>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>
+allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1)
+{
+    return shared_ptr<_Tp>::allocate_shared(__a, __a0, __a1);
+}
+
+template<class _Tp, class _Alloc, class _A0, class _A1, class _A2>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>
+allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2)
+{
+    return shared_ptr<_Tp>::allocate_shared(__a, __a0, __a1, __a2);
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+template<class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
+{
+    return __x.get() == __y.get();
+}
+
+template<class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
+{
+    return !(__x == __y);
+}
+
+template<class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
+{
+    typedef typename common_type<_Tp*, _Up*>::type _Vp;
+    return less<_Vp>()(__x.get(), __y.get());
+}
+
+template<class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
+{
+    return __y < __x;
+}
+
+template<class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
+{
+    return !(__y < __x);
+}
+
+template<class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
+{
+    return !(__x < __y);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
+{
+    return !__x;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
+{
+    return !__x;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
+{
+    return static_cast<bool>(__x);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
+{
+    return static_cast<bool>(__x);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
+{
+    return less<_Tp*>()(__x.get(), nullptr);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
+{
+    return less<_Tp*>()(nullptr, __x.get());
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
+{
+    return nullptr < __x;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
+{
+    return __x < nullptr;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
+{
+    return !(nullptr < __x);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
+{
+    return !(__x < nullptr);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
+{
+    return !(__x < nullptr);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
+{
+    return !(nullptr < __x);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(shared_ptr<_Tp>& __x, shared_ptr<_Tp>& __y) _NOEXCEPT
+{
+    __x.swap(__y);
+}
+
+template<class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_array<_Tp>::value && !is_array<_Up>::value,
+    shared_ptr<_Tp>
+>::type
+static_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
+{
+    return shared_ptr<_Tp>(__r, static_cast<_Tp*>(__r.get()));
+}
+
+template<class _Tp, class _Up>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_array<_Tp>::value && !is_array<_Up>::value,
+    shared_ptr<_Tp>
+>::type
+dynamic_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
+{
+    _Tp* __p = dynamic_cast<_Tp*>(__r.get());
+    return __p ? shared_ptr<_Tp>(__r, __p) : shared_ptr<_Tp>();
+}
+
+template<class _Tp, class _Up>
+typename enable_if
+<
+    is_array<_Tp>::value == is_array<_Up>::value,
+    shared_ptr<_Tp>
+>::type
+const_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
+{
+    typedef typename remove_extent<_Tp>::type _RTp;
+    return shared_ptr<_Tp>(__r, const_cast<_RTp*>(__r.get()));
+}
+
+#ifndef _LIBCPP_NO_RTTI
+
+template<class _Dp, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Dp*
+get_deleter(const shared_ptr<_Tp>& __p) _NOEXCEPT
+{
+    return __p.template __get_deleter<_Dp>();
+}
+
+#endif  // _LIBCPP_NO_RTTI
+
+template<class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY weak_ptr
+{
+public:
+    typedef _Tp element_type;
+private:
+    element_type*        __ptr_;
+    __shared_weak_count* __cntrl_;
+
+public:
+    _LIBCPP_CONSTEXPR weak_ptr() _NOEXCEPT;
+    template<class _Yp> weak_ptr(shared_ptr<_Yp> const& __r,
+                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
+                        _NOEXCEPT;
+    weak_ptr(weak_ptr const& __r) _NOEXCEPT;
+    template<class _Yp> weak_ptr(weak_ptr<_Yp> const& __r,
+                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
+                         _NOEXCEPT;
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    weak_ptr(weak_ptr&& __r) _NOEXCEPT;
+    template<class _Yp> weak_ptr(weak_ptr<_Yp>&& __r,
+                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
+                         _NOEXCEPT;
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    ~weak_ptr();
+
+    weak_ptr& operator=(weak_ptr const& __r) _NOEXCEPT;
+    template<class _Yp>
+        typename enable_if
+        <
+            is_convertible<_Yp*, element_type*>::value,
+            weak_ptr&
+        >::type
+        operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT;
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    weak_ptr& operator=(weak_ptr&& __r) _NOEXCEPT;
+    template<class _Yp>
+        typename enable_if
+        <
+            is_convertible<_Yp*, element_type*>::value,
+            weak_ptr&
+        >::type
+        operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT;
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    template<class _Yp>
+        typename enable_if
+        <
+            is_convertible<_Yp*, element_type*>::value,
+            weak_ptr&
+        >::type
+        operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT;
+
+    void swap(weak_ptr& __r) _NOEXCEPT;
+    void reset() _NOEXCEPT;
+
+    _LIBCPP_INLINE_VISIBILITY
+    long use_count() const _NOEXCEPT
+        {return __cntrl_ ? __cntrl_->use_count() : 0;}
+    _LIBCPP_INLINE_VISIBILITY
+    bool expired() const _NOEXCEPT
+        {return __cntrl_ == 0 || __cntrl_->use_count() == 0;}
+    shared_ptr<_Tp> lock() const _NOEXCEPT;
+    template<class _Up>
+        _LIBCPP_INLINE_VISIBILITY
+        bool owner_before(const shared_ptr<_Up>& __r) const
+        {return __cntrl_ < __r.__cntrl_;}
+    template<class _Up>
+        _LIBCPP_INLINE_VISIBILITY
+        bool owner_before(const weak_ptr<_Up>& __r) const
+        {return __cntrl_ < __r.__cntrl_;}
+
+    template <class _Up> friend class _LIBCPP_TYPE_VIS_ONLY weak_ptr;
+    template <class _Up> friend class _LIBCPP_TYPE_VIS_ONLY shared_ptr;
+};
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_LIBCPP_CONSTEXPR
+weak_ptr<_Tp>::weak_ptr() _NOEXCEPT
+    : __ptr_(0),
+      __cntrl_(0)
+{
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+weak_ptr<_Tp>::weak_ptr(weak_ptr const& __r) _NOEXCEPT
+    : __ptr_(__r.__ptr_),
+      __cntrl_(__r.__cntrl_)
+{
+    if (__cntrl_)
+        __cntrl_->__add_weak();
+}
+
+template<class _Tp>
+template<class _Yp>
+inline _LIBCPP_INLINE_VISIBILITY
+weak_ptr<_Tp>::weak_ptr(shared_ptr<_Yp> const& __r,
+                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
+                         _NOEXCEPT
+    : __ptr_(__r.__ptr_),
+      __cntrl_(__r.__cntrl_)
+{
+    if (__cntrl_)
+        __cntrl_->__add_weak();
+}
+
+template<class _Tp>
+template<class _Yp>
+inline _LIBCPP_INLINE_VISIBILITY
+weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp> const& __r,
+                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
+         _NOEXCEPT
+    : __ptr_(__r.__ptr_),
+      __cntrl_(__r.__cntrl_)
+{
+    if (__cntrl_)
+        __cntrl_->__add_weak();
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+weak_ptr<_Tp>::weak_ptr(weak_ptr&& __r) _NOEXCEPT
+    : __ptr_(__r.__ptr_),
+      __cntrl_(__r.__cntrl_)
+{
+    __r.__ptr_ = 0;
+    __r.__cntrl_ = 0;
+}
+
+template<class _Tp>
+template<class _Yp>
+inline _LIBCPP_INLINE_VISIBILITY
+weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp>&& __r,
+                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
+         _NOEXCEPT
+    : __ptr_(__r.__ptr_),
+      __cntrl_(__r.__cntrl_)
+{
+    __r.__ptr_ = 0;
+    __r.__cntrl_ = 0;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template<class _Tp>
+weak_ptr<_Tp>::~weak_ptr()
+{
+    if (__cntrl_)
+        __cntrl_->__release_weak();
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+weak_ptr<_Tp>&
+weak_ptr<_Tp>::operator=(weak_ptr const& __r) _NOEXCEPT
+{
+    weak_ptr(__r).swap(*this);
+    return *this;
+}
+
+template<class _Tp>
+template<class _Yp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_convertible<_Yp*, _Tp*>::value,
+    weak_ptr<_Tp>&
+>::type
+weak_ptr<_Tp>::operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT
+{
+    weak_ptr(__r).swap(*this);
+    return *this;
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+weak_ptr<_Tp>&
+weak_ptr<_Tp>::operator=(weak_ptr&& __r) _NOEXCEPT
+{
+    weak_ptr(_VSTD::move(__r)).swap(*this);
+    return *this;
+}
+
+template<class _Tp>
+template<class _Yp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_convertible<_Yp*, _Tp*>::value,
+    weak_ptr<_Tp>&
+>::type
+weak_ptr<_Tp>::operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT
+{
+    weak_ptr(_VSTD::move(__r)).swap(*this);
+    return *this;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template<class _Tp>
+template<class _Yp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    is_convertible<_Yp*, _Tp*>::value,
+    weak_ptr<_Tp>&
+>::type
+weak_ptr<_Tp>::operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT
+{
+    weak_ptr(__r).swap(*this);
+    return *this;
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+weak_ptr<_Tp>::swap(weak_ptr& __r) _NOEXCEPT
+{
+    _VSTD::swap(__ptr_, __r.__ptr_);
+    _VSTD::swap(__cntrl_, __r.__cntrl_);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(weak_ptr<_Tp>& __x, weak_ptr<_Tp>& __y) _NOEXCEPT
+{
+    __x.swap(__y);
+}
+
+template<class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+weak_ptr<_Tp>::reset() _NOEXCEPT
+{
+    weak_ptr().swap(*this);
+}
+
+template<class _Tp>
+template<class _Yp>
+shared_ptr<_Tp>::shared_ptr(const weak_ptr<_Yp>& __r,
+                            typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat>::type)
+    : __ptr_(__r.__ptr_),
+      __cntrl_(__r.__cntrl_ ? __r.__cntrl_->lock() : __r.__cntrl_)
+{
+    if (__cntrl_ == 0)
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        throw bad_weak_ptr();
+#else
+        assert(!"bad_weak_ptr");
+#endif
+}
+
+template<class _Tp>
+shared_ptr<_Tp>
+weak_ptr<_Tp>::lock() const _NOEXCEPT
+{
+    shared_ptr<_Tp> __r;
+    __r.__cntrl_ = __cntrl_ ? __cntrl_->lock() : __cntrl_;
+    if (__r.__cntrl_)
+        __r.__ptr_ = __ptr_;
+    return __r;
+}
+
+template <class _Tp> struct owner_less;
+
+template <class _Tp>
+struct _LIBCPP_TYPE_VIS_ONLY owner_less<shared_ptr<_Tp> >
+    : binary_function<shared_ptr<_Tp>, shared_ptr<_Tp>, bool>
+{
+    typedef bool result_type;
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const
+        {return __x.owner_before(__y);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const
+        {return __x.owner_before(__y);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const
+        {return __x.owner_before(__y);}
+};
+
+template <class _Tp>
+struct _LIBCPP_TYPE_VIS_ONLY owner_less<weak_ptr<_Tp> >
+    : binary_function<weak_ptr<_Tp>, weak_ptr<_Tp>, bool>
+{
+    typedef bool result_type;
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(  weak_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const
+        {return __x.owner_before(__y);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const
+        {return __x.owner_before(__y);}
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const
+        {return __x.owner_before(__y);}
+};
+
+template<class _Tp>
+class _LIBCPP_TYPE_VIS_ONLY enable_shared_from_this
+{
+    mutable weak_ptr<_Tp> __weak_this_;
+protected:
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    enable_shared_from_this() _NOEXCEPT {}
+    _LIBCPP_INLINE_VISIBILITY
+    enable_shared_from_this(enable_shared_from_this const&) _NOEXCEPT {}
+    _LIBCPP_INLINE_VISIBILITY
+    enable_shared_from_this& operator=(enable_shared_from_this const&) _NOEXCEPT
+        {return *this;}
+    _LIBCPP_INLINE_VISIBILITY
+    ~enable_shared_from_this() {}
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    shared_ptr<_Tp> shared_from_this()
+        {return shared_ptr<_Tp>(__weak_this_);}
+    _LIBCPP_INLINE_VISIBILITY
+    shared_ptr<_Tp const> shared_from_this() const
+        {return shared_ptr<const _Tp>(__weak_this_);}
+
+    template <class _Up> friend class shared_ptr;
+};
+
+template <class _Tp>
+struct _LIBCPP_TYPE_VIS_ONLY hash<shared_ptr<_Tp> >
+{
+    typedef shared_ptr<_Tp>      argument_type;
+    typedef size_t               result_type;
+    _LIBCPP_INLINE_VISIBILITY
+    result_type operator()(const argument_type& __ptr) const _NOEXCEPT
+    {
+        return hash<_Tp*>()(__ptr.get());
+    }
+};
+
+template<class _CharT, class _Traits, class _Yp>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p);
+
+#if __has_feature(cxx_atomic) && !defined(_LIBCPP_HAS_NO_THREADS)
+
+class _LIBCPP_TYPE_VIS __sp_mut
+{
+    void* __lx;
+public:
+    void lock() _NOEXCEPT;
+    void unlock() _NOEXCEPT;
+
+private:
+    _LIBCPP_CONSTEXPR __sp_mut(void*) _NOEXCEPT;
+    __sp_mut(const __sp_mut&);
+    __sp_mut& operator=(const __sp_mut&);
+
+    friend _LIBCPP_FUNC_VIS __sp_mut& __get_sp_mut(const void*);
+};
+
+_LIBCPP_FUNC_VIS __sp_mut& __get_sp_mut(const void*);
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_is_lock_free(const shared_ptr<_Tp>*)
+{
+    return false;
+}
+
+template <class _Tp>
+shared_ptr<_Tp>
+atomic_load(const shared_ptr<_Tp>* __p)
+{
+    __sp_mut& __m = __get_sp_mut(__p);
+    __m.lock();
+    shared_ptr<_Tp> __q = *__p;
+    __m.unlock();
+    return __q;
+}
+  
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>
+atomic_load_explicit(const shared_ptr<_Tp>* __p, memory_order)
+{
+    return atomic_load(__p);
+}
+
+template <class _Tp>
+void
+atomic_store(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
+{
+    __sp_mut& __m = __get_sp_mut(__p);
+    __m.lock();
+    __p->swap(__r);
+    __m.unlock();
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+atomic_store_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
+{
+    atomic_store(__p, __r);
+}
+
+template <class _Tp>
+shared_ptr<_Tp>
+atomic_exchange(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
+{
+    __sp_mut& __m = __get_sp_mut(__p);
+    __m.lock();
+    __p->swap(__r);
+    __m.unlock();
+    return __r;
+}
+  
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+shared_ptr<_Tp>
+atomic_exchange_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
+{
+    return atomic_exchange(__p, __r);
+}
+
+template <class _Tp>
+bool
+atomic_compare_exchange_strong(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
+{
+    __sp_mut& __m = __get_sp_mut(__p);
+    __m.lock();
+    if (__p->__owner_equivalent(*__v))
+    {
+        *__p = __w;
+        __m.unlock();
+        return true;
+    }
+    *__v = *__p;
+    __m.unlock();
+    return false;
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_compare_exchange_weak(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
+{
+    return atomic_compare_exchange_strong(__p, __v, __w);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_compare_exchange_strong_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
+                                        shared_ptr<_Tp> __w, memory_order, memory_order)
+{
+    return atomic_compare_exchange_strong(__p, __v, __w);
+}
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+atomic_compare_exchange_weak_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
+                                      shared_ptr<_Tp> __w, memory_order, memory_order)
+{
+    return atomic_compare_exchange_weak(__p, __v, __w);
+}
+
+#endif  // __has_feature(cxx_atomic) && !defined(_LIBCPP_HAS_NO_THREADS)
+
+//enum class
+struct _LIBCPP_TYPE_VIS pointer_safety
+{
+    enum __lx
+    {
+        relaxed,
+        preferred,
+        strict
+    };
+
+    __lx __v_;
+
+    _LIBCPP_INLINE_VISIBILITY
+    pointer_safety(__lx __v) : __v_(__v) {}
+    _LIBCPP_INLINE_VISIBILITY
+    operator int() const {return __v_;}
+};
+
+_LIBCPP_FUNC_VIS void declare_reachable(void* __p);
+_LIBCPP_FUNC_VIS void declare_no_pointers(char* __p, size_t __n);
+_LIBCPP_FUNC_VIS void undeclare_no_pointers(char* __p, size_t __n);
+_LIBCPP_FUNC_VIS pointer_safety get_pointer_safety() _NOEXCEPT;
+_LIBCPP_FUNC_VIS void* __undeclare_reachable(void* __p);
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp*
+undeclare_reachable(_Tp* __p)
+{
+    return static_cast<_Tp*>(__undeclare_reachable(__p));
+}
+
+_LIBCPP_FUNC_VIS void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
+
+// --- Helper for container swap --
+template <typename _Alloc>
+_LIBCPP_INLINE_VISIBILITY
+void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
+#if _LIBCPP_STD_VER >= 14
+    _NOEXCEPT
+#else
+    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
+#endif
+{
+    __swap_allocator(__a1, __a2, 
+      integral_constant<bool, _VSTD::allocator_traits<_Alloc>::propagate_on_container_swap::value>());
+}
+
+template <typename _Alloc>
+_LIBCPP_INLINE_VISIBILITY
+void __swap_allocator(_Alloc & __a1, _Alloc & __a2, true_type)
+#if _LIBCPP_STD_VER >= 14
+    _NOEXCEPT
+#else
+    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
+#endif
+{
+    using _VSTD::swap;
+    swap(__a1, __a2);
+}
+
+template <typename _Alloc>
+_LIBCPP_INLINE_VISIBILITY
+void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}
+
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_MEMORY

diff --git a/libcxx/include/module.modulemap b/libcxx/include/module.modulemap
new file mode 100644
index 0000000..3c0700e
--- /dev/null
+++ b/libcxx/include/module.modulemap

@@ -0,0 +1,473 @@
+module std [system] {
+  // FIXME: The standard does not require that each of these submodules
+  // re-exports its imported modules. We should provide an alternative form of
+  // export that issues a warning if a name from the submodule is used, and
+  // use that to provide a 'strict mode' for libc++.
+  module algorithm {
+    header "algorithm"
+    export initializer_list
+    export *
+  }
+  module array {
+    header "array"
+    export initializer_list
+    export *
+  }
+  module atomic {
+    header "atomic"
+    export *
+    requires cplusplus11
+  }
+  module bitset {
+    header "bitset"
+    export string
+    export iosfwd
+    export *
+  }
+  // No submodule for cassert. It fundamentally needs repeated, textual inclusion.
+  module ccomplex {
+    header "ccomplex"
+    export complex
+    export *
+  }
+  module cctype {
+    header "cctype"
+    export *
+  }
+  module cerrno {
+    header "cerrno"
+/*
+    export_macros    ECONNREFUSED, EIO,          ENODEV,      ENOTEMPTY,       ERANGE,
+      E2BIG,         ECONNRESET,   EISCONN,      ENOENT,      ENOTRECOVERABLE, EROFS,
+      EACCES,        EDEADLK,      EISDIR,       ENOEXEC,     ENOTSOCK,        ESPIPE,
+      EADDRINUSE,    EDESTADDRREQ, ELOOP,        ENOLCK,      ENOTSUP,         ESRCH,
+      EADDRNOTAVAIL, EDOM,         EMFILE,       ENOLINK,     ENOTTY,          ETIME,
+      EAFNOSUPPORT,  EEXIST,       EMLINK,       ENOMEM,      ENXIO,           ETIMEDOUT,
+      EAGAIN,        EFAULT,       EMSGSIZE,     ENOMSG,      EOPNOTSUPP,      ETXTBSY,
+      EALREADY,      EFBIG,        ENAMETOOLONG, ENOPROTOOPT, EOVERFLOW,       EWOULDBLOCK,
+      EBADF,         EHOSTUNREACH, ENETDOWN,     ENOSPC,      EOWNERDEAD,      EXDEV,
+      EBADMSG,       EIDRM,        ENETRESET,    ENOSR,       EPERM,           errno,
+      EBUSY,         EILSEQ,       ENETUNREACH,  ENOSTR,      EPIPE,
+      ECANCELED,     EINPROGRESS,  ENFILE,       ENOSYS,      EPROTO,
+      ECHILD,        EINTR,        ENOBUFS,      ENOTCONN,    EPROTONOSUPPORT,
+      ECONNABORTED,  EINVAL,       ENODATA,      ENOTDIR,     EPROTOTYPE
+*/
+    export *
+  }
+  module cfenv {
+    header "cfenv"
+/*
+    export_macros FE_ALL_EXCEPT, FE_DIVBYZERO, FE_INEXACT, FE_INVALID, FE_OVERFLOW,
+                  FE_UNDERFLOW, FE_DOWNWARD, FE_TONEAREST, FE_TOWARDZERO, FE_UPWARD,
+                  FE_DFL_ENV
+*/
+    export *
+  }
+  module cfloat {
+    header "cfloat"
+/*
+    export_macros FLT_EVAL_METHOD, FLT_RADIX, FLT_ROUNDS,
+                  FLT_DIG, FLT_EPSILON, FLT_MANT_DIG,
+                  FLT_MAX, FLT_MAX_10_EXP, FLT_MAX_EXP,
+                  FLT_MIN, FLT_MIN_10_EXP, FLT_MIN_EXP,
+                  DBL_DIG, DBL_EPSILON, DBL_MANT_DIG,
+                  DBL_MAX, DBL_MAX_10_EXP, DBL_MAX_EXP,
+                  DBL_MIN, DBL_MIN_10_EXP, DBL_MIN_EXP,
+                  LDBL_DIG, LDBL_EPSILON, LDBL_MANT_DIG,
+                  LDBL_MAX, LDBL_MAX_10_EXP, LDBL_MAX_EXP,
+                  LDBL_MIN, LDBL_MIN_10_EXP, LDBL_MIN_EXP
+*/
+    export *
+  }
+  module chrono {
+    header "chrono"
+    export *
+  }
+  module cinttypes {
+    header "cinttypes"
+    export cstdint
+/*
+    export_macros
+      PRId8, PRId16, PRId32, PRId64, PRIdFAST8, PRIdFAST16, PRIdFAST32, PRIdFAST64, PRIdLEAST8, PRIdLEAST16, PRIdLEAST32, PRIdLEAST64, PRIdMAX, PRIdPTR,
+      PRIi8, PRIi16, PRIi32, PRIi64, PRIiFAST8, PRIiFAST16, PRIiFAST32, PRIiFAST64, PRIiLEAST8, PRIiLEAST16, PRIiLEAST32, PRIiLEAST64, PRIiMAX, PRIiPTR,
+      PRIo8, PRIo16, PRIo32, PRIo64, PRIoFAST8, PRIoFAST16, PRIoFAST32, PRIoFAST64, PRIoLEAST8, PRIoLEAST16, PRIoLEAST32, PRIoLEAST64, PRIoMAX, PRIoPTR,
+      PRIu8, PRIu16, PRIu32, PRIu64, PRIuFAST8, PRIuFAST16, PRIuFAST32, PRIuFAST64, PRIuLEAST8, PRIuLEAST16, PRIuLEAST32, PRIuLEAST64, PRIuMAX, PRIuPTR,
+      PRIx8, PRIx16, PRIx32, PRIx64, PRIxFAST8, PRIxFAST16, PRIxFAST32, PRIxFAST64, PRIxLEAST8, PRIxLEAST16, PRIxLEAST32, PRIxLEAST64, PRIxMAX, PRIxPTR,
+      PRIX8, PRIX16, PRIX32, PRIX64, PRIXFAST8, PRIXFAST16, PRIXFAST32, PRIXFAST64, PRIXLEAST8, PRIXLEAST16, PRIXLEAST32, PRIXLEAST64, PRIXMAX, PRIXPTR,
+      SCNd8, SCNd16, SCNd32, SCNd64, SCNdFAST8, SCNdFAST16, SCNdFAST32, SCNdFAST64, SCNdLEAST8, SCNdLEAST16, SCNdLEAST32, SCNdLEAST64, SCNdMAX, SCNdPTR,
+      SCNi8, SCNi16, SCNi32, SCNi64, SCNiFAST8, SCNiFAST16, SCNiFAST32, SCNiFAST64, SCNiLEAST8, SCNiLEAST16, SCNiLEAST32, SCNiLEAST64, SCNiMAX, SCNiPTR,
+      SCNo8, SCNo16, SCNo32, SCNo64, SCNoFAST8, SCNoFAST16, SCNoFAST32, SCNoFAST64, SCNoLEAST8, SCNoLEAST16, SCNoLEAST32, SCNoLEAST64, SCNoMAX, SCNoPTR,
+      SCNu8, SCNu16, SCNu32, SCNu64, SCNuFAST8, SCNuFAST16, SCNuFAST32, SCNuFAST64, SCNuLEAST8, SCNuLEAST16, SCNuLEAST32, SCNuLEAST64, SCNuMAX, SCNuPTR,
+      SCNx8, SCNx16, SCNx32, SCNx64, SCNxFAST8, SCNxFAST16, SCNxFAST32, SCNxFAST64, SCNxLEAST8, SCNxLEAST16, SCNxLEAST32, SCNxLEAST64, SCNxMAX, SCNxPTR,
+      SCNX8, SCNX16, SCNX32, SCNX64, SCNXFAST8, SCNXFAST16, SCNXFAST32, SCNXFAST64, SCNXLEAST8, SCNXLEAST16, SCNXLEAST32, SCNXLEAST64, SCNXMAX, SCNXPTR
+*/
+    export *
+  }
+  module ciso646 {
+    header "ciso646"
+    export *
+  }
+  module climits {
+    header "climits"
+/*
+    export_macros CHAR_BIT,  CHAR_MIN,  CHAR_MAX,
+                  SCHAR_MIN, SCHAR_MAX, UCHAR_MAX,
+                  SHRT_MIN,  SHRT_MAX,  USHRT_MAX,
+                  INT_MIN,   INT_MAX,   UINT_MAX,
+                  LONG_MIN,  LONG_MAX,  ULONG_MAX,
+                  LLONG_MIN, LLONG_MAX, ULLONG_MAX,
+                  MB_LEN_MAX
+*/
+    export *
+  }
+  module clocale {
+    header "clocale"
+/*
+    export_macros LC_ALL, LC_COLLATE, LC_CTYPE, LC_MONETARY, LC_NUMERIC, LC_TIME, NULL
+*/
+    export *
+  }
+  module cmath {
+    header "cmath"
+/*
+    export_macros FP_FAST_FMA, FP_FAST_FMAF, FP_FAST_FMAL, FP_ILOGBO, FP_ILOGBNAN,
+                  FP_INFINITE, FP_NAN, FP_NORMAL, FP_SUBNORMAL, FP_ZERO,
+                  HUGE_VAL, HUGE_VALF, HUGE_VALL, INFINITY, NAN,
+                  MATH_ERRNO, MATH_ERREXCEPT, math_errhandling
+*/
+    export *
+  }
+  module codecvt {
+    header "codecvt"
+    export *
+  }
+  module complex {
+    header "complex"
+    export *
+  }
+  module condition_variable {
+    header "condition_variable"
+    export *
+  }
+  module csetjmp {
+    header "csetjmp"
+/*
+    export_macros setjmp
+*/
+    export *
+  }
+  module csignal {
+    header "csignal"
+/*
+    export_macros SIGABRT, SIGFPE, SIGILL, SIGINT, SIGSEGV, SIGTERM,
+                  SIG_DFL, SIG_IGN, SIG_ERR
+*/
+    export *
+  }
+  module cstdarg {
+    header "cstdarg"
+/*
+    export_macros va_arg, va_start, va_end, va_copy
+*/
+    export *
+  }
+  module cstdbool {
+    header "cstdbool"
+/*
+    export_macros __bool_true_false_are_defined
+*/
+    export *
+  }
+  module cstddef {
+    header "cstddef"
+/*
+    export_macros NULL, offsetof
+*/
+    export *
+  }
+  module cstdint {
+    header "cstdint"
+/*
+    export_macros
+      INT_8_MIN, INT_8_MAX, UINT_8_MAX, INT_16_MIN, INT_16_MAX, UINT_16_MAX,
+      INT_32_MIN, INT_32_MAX, UINT_32_MAX, INT_64_MIN, INT_64_MAX, UINT_64_MAX,
+      INT_FAST8_MIN, INT_FAST8_MAX, UINT_FAST8_MAX, INT_FAST16_MIN, INT_FAST16_MAX, UINT_FAST16_MAX,
+      INT_FAST32_MIN, INT_FAST32_MAX, UINT_FAST32_MAX, INT_FAST64_MIN, INT_FAST64_MAX, UINT_FAST64_MAX,
+      INT_LEAST8_MIN, INT_LEAST8_MAX, UINT_LEAST8_MAX, INT_LEAST16_MIN, INT_LEAST16_MAX, UINT_LEAST16_MAX,
+      INT_LEAST32_MIN, INT_LEAST32_MAX, UINT_LEAST32_MAX, INT_LEAST64_MIN, INT_LEAST64_MAX, UINT_LEAST64_MAX,
+      INT_MAX_MIN, INT_MAX_MAX, UINT_MAX_MAX, INT_PTR_MIN, INT_PTR_MAX, UINT_PTR_MAX,
+      PTRDIFF_MIN, PTRDIFF_MAX, SIG_ATOMIC_MIN, SIG_ATOMIC_MAX, WCHAR_MIN, WCHAR_MAX, WINT_MIN, WINT_MAX,
+      SIZE_MAX
+*/
+    export *
+  }
+  module cstdio {
+    header "cstdio"
+/*
+    export_macros BUFSIZ, EOF, FILENAME_MAX, FOPEN_MAX, L_tmpnam, NULL,
+                  SEEK_CUR, SEEK_END, SEEK_SET, TMP_MAX, _IOFBF, _IOLBF,
+                  stdin, stdout, stderr
+*/
+    export *
+  }
+  module cstdlib {
+    header "cstdlib"
+/*
+    export_macros RAND_MAX
+*/
+    export *
+  }
+  module cstring {
+    header "cstring"
+/*
+    export_macros NULL
+*/
+    export *
+  }
+  module ctgmath {
+    header "ctgmath"
+    export ccomplex
+    export cmath
+    export *
+  }
+  module ctime {
+    header "ctime"
+/*
+    export_macros NULL, CLOCKS_PER_SEC
+*/
+    export *
+  }
+  module cwchar {
+    header "cwchar"
+/*
+    export_macros NULL, WCHAR_MAX, WCHAR_MIN, WEOF
+*/
+    export *
+  }
+  module cwctype {
+    header "cwctype"
+/*
+    export_macros WEOF
+*/
+    export *
+  }
+  module deque {
+    header "deque"
+    export initializer_list
+    export *
+  }
+  module exception {
+    header "exception"
+    export *
+  }
+  module forward_list {
+    header "forward_list"
+    export initializer_list
+    export *
+  }
+  module fstream {
+    header "fstream"
+    export *
+  }
+  module functional {
+    header "functional"
+    export *
+  }
+  module future {
+    header "future"
+    export *
+  }
+  module initializer_list {
+    header "initializer_list"
+    export *
+  }
+  module iomanip {
+    header "iomanip"
+    export *
+  }
+  module ios {
+    header "ios"
+    export iosfwd
+    export *
+  }
+  module iosfwd {
+    header "iosfwd"
+    export *
+  }
+  module iostream {
+    header "iostream"
+    export ios
+    export streambuf
+    export istream
+    export ostream
+    export *
+  }
+  module istream {
+    header "istream"
+    // FIXME: should re-export ios, streambuf?
+    export *
+  }
+  module iterator {
+    header "iterator"
+    export *
+  }
+  module limits {
+    header "limits"
+    export *
+  }
+  module list {
+    header "list"
+    export initializer_list
+    export *
+  }
+  module locale {
+    header "locale"
+    export *
+  }
+  module map {
+    header "map"
+    export initializer_list
+    export *
+  }
+  module memory {
+    header "memory"
+    export *
+  }
+  module mutex {
+    header "mutex"
+    export *
+  }
+  module new {
+    header "new"
+    export *
+  }
+  module numeric {
+    header "numeric"
+    export *
+  }
+  module ostream {
+    header "ostream"
+    // FIXME: should re-export ios, streambuf?
+    export *
+  }
+  module queue {
+    header "queue"
+    export initializer_list
+    export *
+  }
+  module random {
+    header "random"
+    export initializer_list
+    export *
+  }
+  module ratio {
+    header "ratio"
+    export *
+  }
+  module regex {
+    header "regex"
+    export initializer_list
+    export *
+  }
+  module scoped_allocator {
+    header "scoped_allocator"
+    export *
+  }
+  module set {
+    header "set"
+    export initializer_list
+    export *
+  }
+  module sstream {
+    header "sstream"
+    // FIXME: should re-export istream, ostream, ios, streambuf, string?
+    export *
+  }
+  module stack {
+    header "stack"
+    export initializer_list
+    export *
+  }
+  module stdexcept {
+    header "stdexcept"
+    export *
+  }
+  module streambuf {
+    header "streambuf"
+    export *
+  }
+  module string {
+    header "string"
+    export initializer_list
+    export *
+  }
+  module strstream {
+    header "strstream"
+    requires !cplusplus11
+  }
+  module system_error {
+    header "system_error"
+    export *
+  }
+  module thread {
+    header "thread"
+    export *
+  }
+  module tuple {
+    header "tuple"
+    export *
+  }
+  module type_traits {
+    header "type_traits"
+    export *
+  }
+  module typeindex {
+    header "typeindex"
+    export *
+  }
+  module typeinfo {
+    header "typeinfo"
+    export *
+  }
+  module unordered_map {
+    header "unordered_map"
+    export initializer_list
+    export *
+  }
+  module unordered_set {
+    header "unordered_set"
+    export initializer_list
+    export *
+  }
+  module utility {
+    header "utility"
+    export initializer_list
+    export *
+  }
+  module valarray {
+    header "valarray"
+    export initializer_list
+    export *
+  }
+  module vector {
+    header "vector"
+    export initializer_list
+    export *
+  }
+
+  // FIXME: These should be private.
+  module __bit_reference { header "__bit_reference" export * }
+  module __config { header "__config" export * }
+  module __debug { header "__debug" export * }
+  module __functional_base { header "__functional_base" export * }
+  module __hash_table { header "__hash_table" export * }
+  module __locale { header "__locale" export * }
+  module __mutex_base { header "__mutex_base" export * }
+  module __split_buffer { header "__split_buffer" export * }
+  module __sso_allocator { header "__sso_allocator" export * }
+  module __std_stream { header "__std_stream" export * }
+  module __tree { header "__tree" export * }
+  module __tuple { header "__tuple" export * }
+  module __undef_min_max { header "__undef_min_max" export * }
+  module __undef___deallocate { header "__undef___deallocate" export * }
+}

diff --git a/libcxx/include/mutex b/libcxx/include/mutex
new file mode 100644
index 0000000..373d75b
--- /dev/null
+++ b/libcxx/include/mutex

@@ -0,0 +1,582 @@
+// -*- C++ -*-
+//===--------------------------- mutex ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_MUTEX
+#define _LIBCPP_MUTEX
+
+/*
+    mutex synopsis
+
+namespace std
+{
+
+class mutex
+{
+public:
+     constexpr mutex() noexcept;
+     ~mutex();
+
+    mutex(const mutex&) = delete;
+    mutex& operator=(const mutex&) = delete;
+
+    void lock();
+    bool try_lock();
+    void unlock();
+
+    typedef pthread_mutex_t* native_handle_type;
+    native_handle_type native_handle();
+};
+
+class recursive_mutex
+{
+public:
+     recursive_mutex();
+     ~recursive_mutex();
+
+    recursive_mutex(const recursive_mutex&) = delete;
+    recursive_mutex& operator=(const recursive_mutex&) = delete;
+
+    void lock();
+    bool try_lock() noexcept;
+    void unlock();
+
+    typedef pthread_mutex_t* native_handle_type;
+    native_handle_type native_handle();
+};
+
+class timed_mutex
+{
+public:
+     timed_mutex();
+     ~timed_mutex();
+
+    timed_mutex(const timed_mutex&) = delete;
+    timed_mutex& operator=(const timed_mutex&) = delete;
+
+    void lock();
+    bool try_lock();
+    template <class Rep, class Period>
+        bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
+    template <class Clock, class Duration>
+        bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
+    void unlock();
+};
+
+class recursive_timed_mutex
+{
+public:
+     recursive_timed_mutex();
+     ~recursive_timed_mutex();
+
+    recursive_timed_mutex(const recursive_timed_mutex&) = delete;
+    recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete;
+
+    void lock();
+    bool try_lock() noexcept;
+    template <class Rep, class Period>
+        bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
+    template <class Clock, class Duration>
+        bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
+    void unlock();
+};
+
+struct defer_lock_t {};
+struct try_to_lock_t {};
+struct adopt_lock_t {};
+
+constexpr defer_lock_t  defer_lock{};
+constexpr try_to_lock_t try_to_lock{};
+constexpr adopt_lock_t  adopt_lock{};
+
+template <class Mutex>
+class lock_guard
+{
+public:
+    typedef Mutex mutex_type;
+
+    explicit lock_guard(mutex_type& m);
+    lock_guard(mutex_type& m, adopt_lock_t);
+    ~lock_guard();
+
+    lock_guard(lock_guard const&) = delete;
+    lock_guard& operator=(lock_guard const&) = delete;
+};
+
+template <class Mutex>
+class unique_lock
+{
+public:
+    typedef Mutex mutex_type;
+    unique_lock() noexcept;
+    explicit unique_lock(mutex_type& m);
+    unique_lock(mutex_type& m, defer_lock_t) noexcept;
+    unique_lock(mutex_type& m, try_to_lock_t);
+    unique_lock(mutex_type& m, adopt_lock_t);
+    template <class Clock, class Duration>
+        unique_lock(mutex_type& m, const chrono::time_point<Clock, Duration>& abs_time);
+    template <class Rep, class Period>
+        unique_lock(mutex_type& m, const chrono::duration<Rep, Period>& rel_time);
+    ~unique_lock();
+
+    unique_lock(unique_lock const&) = delete;
+    unique_lock& operator=(unique_lock const&) = delete;
+
+    unique_lock(unique_lock&& u) noexcept;
+    unique_lock& operator=(unique_lock&& u) noexcept;
+
+    void lock();
+    bool try_lock();
+
+    template <class Rep, class Period>
+        bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
+    template <class Clock, class Duration>
+        bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
+
+    void unlock();
+
+    void swap(unique_lock& u) noexcept;
+    mutex_type* release() noexcept;
+
+    bool owns_lock() const noexcept;
+    explicit operator bool () const noexcept;
+    mutex_type* mutex() const noexcept;
+};
+
+template <class Mutex>
+  void swap(unique_lock<Mutex>& x, unique_lock<Mutex>& y) noexcept;
+
+template <class L1, class L2, class... L3>
+  int try_lock(L1&, L2&, L3&...);
+template <class L1, class L2, class... L3>
+  void lock(L1&, L2&, L3&...);
+
+struct once_flag
+{
+    constexpr once_flag() noexcept;
+
+    once_flag(const once_flag&) = delete;
+    once_flag& operator=(const once_flag&) = delete;
+};
+
+template<class Callable, class ...Args>
+  void call_once(once_flag& flag, Callable&& func, Args&&... args);
+
+}  // std
+
+*/
+
+#include <__config>
+#include <__mutex_base>
+#include <functional>
+#include <memory>
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+#include <tuple>
+#endif
+#include <sched.h>
+
+#include <__undef_min_max>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#ifndef _LIBCPP_HAS_NO_THREADS
+
+class _LIBCPP_TYPE_VIS recursive_mutex
+{
+    pthread_mutex_t __m_;
+
+public:
+     recursive_mutex();
+     ~recursive_mutex();
+
+private:
+    recursive_mutex(const recursive_mutex&); // = delete;
+    recursive_mutex& operator=(const recursive_mutex&); // = delete;
+
+public:
+    void lock();
+    bool try_lock() _NOEXCEPT;
+    void unlock()  _NOEXCEPT;
+
+    typedef pthread_mutex_t* native_handle_type;
+    _LIBCPP_INLINE_VISIBILITY
+    native_handle_type native_handle() {return &__m_;}
+};
+
+class _LIBCPP_TYPE_VIS timed_mutex
+{
+    mutex              __m_;
+    condition_variable __cv_;
+    bool               __locked_;
+public:
+     timed_mutex();
+     ~timed_mutex();
+
+private:
+    timed_mutex(const timed_mutex&); // = delete;
+    timed_mutex& operator=(const timed_mutex&); // = delete;
+
+public:
+    void lock();
+    bool try_lock() _NOEXCEPT;
+    template <class _Rep, class _Period>
+        _LIBCPP_INLINE_VISIBILITY
+        bool try_lock_for(const chrono::duration<_Rep, _Period>& __d)
+            {return try_lock_until(chrono::steady_clock::now() + __d);}
+    template <class _Clock, class _Duration>
+        bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
+    void unlock() _NOEXCEPT;
+};
+
+template <class _Clock, class _Duration>
+bool
+timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
+{
+    using namespace chrono;
+    unique_lock<mutex> __lk(__m_);
+    bool no_timeout = _Clock::now() < __t;
+    while (no_timeout && __locked_)
+        no_timeout = __cv_.wait_until(__lk, __t) == cv_status::no_timeout;
+    if (!__locked_)
+    {
+        __locked_ = true;
+        return true;
+    }
+    return false;
+}
+
+class _LIBCPP_TYPE_VIS recursive_timed_mutex
+{
+    mutex              __m_;
+    condition_variable __cv_;
+    size_t             __count_;
+    pthread_t          __id_;
+public:
+     recursive_timed_mutex();
+     ~recursive_timed_mutex();
+
+private:
+    recursive_timed_mutex(const recursive_timed_mutex&); // = delete;
+    recursive_timed_mutex& operator=(const recursive_timed_mutex&); // = delete;
+
+public:
+    void lock();
+    bool try_lock() _NOEXCEPT;
+    template <class _Rep, class _Period>
+        _LIBCPP_INLINE_VISIBILITY
+        bool try_lock_for(const chrono::duration<_Rep, _Period>& __d)
+            {return try_lock_until(chrono::steady_clock::now() + __d);}
+    template <class _Clock, class _Duration>
+        bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
+    void unlock() _NOEXCEPT;
+};
+
+template <class _Clock, class _Duration>
+bool
+recursive_timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
+{
+    using namespace chrono;
+    pthread_t __id = pthread_self();
+    unique_lock<mutex> lk(__m_);
+    if (pthread_equal(__id, __id_))
+    {
+        if (__count_ == numeric_limits<size_t>::max())
+            return false;
+        ++__count_;
+        return true;
+    }
+    bool no_timeout = _Clock::now() < __t;
+    while (no_timeout && __count_ != 0)
+        no_timeout = __cv_.wait_until(lk, __t) == cv_status::no_timeout;
+    if (__count_ == 0)
+    {
+        __count_ = 1;
+        __id_ = __id;
+        return true;
+    }
+    return false;
+}
+
+template <class _L0, class _L1>
+int
+try_lock(_L0& __l0, _L1& __l1)
+{
+    unique_lock<_L0> __u0(__l0, try_to_lock);
+    if (__u0.owns_lock())
+    {
+        if (__l1.try_lock())
+        {
+            __u0.release();
+            return -1;
+        }
+        else
+            return 1;
+    }
+    return 0;
+}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _L0, class _L1, class _L2, class... _L3>
+int
+try_lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3)
+{
+    int __r = 0;
+    unique_lock<_L0> __u0(__l0, try_to_lock);
+    if (__u0.owns_lock())
+    {
+        __r = try_lock(__l1, __l2, __l3...);
+        if (__r == -1)
+            __u0.release();
+        else
+            ++__r;
+    }
+    return __r;
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+template <class _L0, class _L1>
+void
+lock(_L0& __l0, _L1& __l1)
+{
+    while (true)
+    {
+        {
+            unique_lock<_L0> __u0(__l0);
+            if (__l1.try_lock())
+            {
+                __u0.release();
+                break;
+            }
+        }
+        sched_yield();
+        {
+            unique_lock<_L1> __u1(__l1);
+            if (__l0.try_lock())
+            {
+                __u1.release();
+                break;
+            }
+        }
+        sched_yield();
+    }
+}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _L0, class _L1, class _L2, class ..._L3>
+void
+__lock_first(int __i, _L0& __l0, _L1& __l1, _L2& __l2, _L3& ...__l3)
+{
+    while (true)
+    {
+        switch (__i)
+        {
+        case 0:
+            {
+                unique_lock<_L0> __u0(__l0);
+                __i = try_lock(__l1, __l2, __l3...);
+                if (__i == -1)
+                {
+                    __u0.release();
+                    return;
+                }
+            }
+            ++__i;
+            sched_yield();
+            break;
+        case 1:
+            {
+                unique_lock<_L1> __u1(__l1);
+                __i = try_lock(__l2, __l3..., __l0);
+                if (__i == -1)
+                {
+                    __u1.release();
+                    return;
+                }
+            }
+            if (__i == sizeof...(_L3) + 1)
+                __i = 0;
+            else
+                __i += 2;
+            sched_yield();
+            break;
+        default:
+            __lock_first(__i - 2, __l2, __l3..., __l0, __l1);
+            return;
+        }
+    }
+}
+
+template <class _L0, class _L1, class _L2, class ..._L3>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3& ...__l3)
+{
+    __lock_first(0, __l0, __l1, __l2, __l3...);
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+#endif // !_LIBCPP_HAS_NO_THREADS
+
+struct _LIBCPP_TYPE_VIS_ONLY once_flag;
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template<class _Callable, class... _Args>
+_LIBCPP_INLINE_VISIBILITY
+void call_once(once_flag&, _Callable&&, _Args&&...);
+
+#else  // _LIBCPP_HAS_NO_VARIADICS
+
+template<class _Callable>
+_LIBCPP_INLINE_VISIBILITY
+void call_once(once_flag&, _Callable&);
+
+template<class _Callable>
+_LIBCPP_INLINE_VISIBILITY
+void call_once(once_flag&, const _Callable&);
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+struct _LIBCPP_TYPE_VIS_ONLY once_flag
+{
+    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_CONSTEXPR
+        once_flag() _NOEXCEPT : __state_(0) {}
+
+private:
+    once_flag(const once_flag&); // = delete;
+    once_flag& operator=(const once_flag&); // = delete;
+
+    unsigned long __state_;
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    template<class _Callable, class... _Args>
+    friend
+    void call_once(once_flag&, _Callable&&, _Args&&...);
+#else  // _LIBCPP_HAS_NO_VARIADICS
+    template<class _Callable>
+    friend
+    void call_once(once_flag&, _Callable&);
+
+    template<class _Callable>
+    friend
+    void call_once(once_flag&, const _Callable&);
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+};
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Fp>
+class __call_once_param
+{
+    _Fp& __f_;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __call_once_param(_Fp& __f) : __f_(__f) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void operator()()
+    {
+        typedef typename __make_tuple_indices<tuple_size<_Fp>::value, 1>::type _Index;
+        __execute(_Index());
+    }
+
+private:
+    template <size_t ..._Indices>
+    _LIBCPP_INLINE_VISIBILITY
+    void __execute(__tuple_indices<_Indices...>)
+    {
+        __invoke(_VSTD::get<0>(_VSTD::move(__f_)), _VSTD::get<_Indices>(_VSTD::move(__f_))...);
+    }
+};
+
+#else
+
+template <class _Fp>
+class __call_once_param
+{
+    _Fp& __f_;
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    explicit __call_once_param(_Fp& __f) : __f_(__f) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void operator()()
+    {
+        __f_();
+    }
+};
+
+#endif
+
+template <class _Fp>
+void
+__call_once_proxy(void* __vp)
+{
+    __call_once_param<_Fp>* __p = static_cast<__call_once_param<_Fp>*>(__vp);
+    (*__p)();
+}
+
+_LIBCPP_FUNC_VIS void __call_once(volatile unsigned long&, void*, void(*)(void*));
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template<class _Callable, class... _Args>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+call_once(once_flag& __flag, _Callable&& __func, _Args&&... __args)
+{
+    if (__libcpp_relaxed_load(&__flag.__state_) != ~0ul)
+    {
+        typedef tuple<_Callable&&, _Args&&...> _Gp;
+        _Gp __f(_VSTD::forward<_Callable>(__func), _VSTD::forward<_Args>(__args)...);
+        __call_once_param<_Gp> __p(__f);
+        __call_once(__flag.__state_, &__p, &__call_once_proxy<_Gp>);
+    }
+}
+
+#else  // _LIBCPP_HAS_NO_VARIADICS
+
+template<class _Callable>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+call_once(once_flag& __flag, _Callable& __func)
+{
+    if (__libcpp_relaxed_load(&__flag.__state_) != ~0ul)
+    {
+        __call_once_param<_Callable> __p(__func);
+        __call_once(__flag.__state_, &__p, &__call_once_proxy<_Callable>);
+    }
+}
+
+template<class _Callable>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+call_once(once_flag& __flag, const _Callable& __func)
+{
+    if (__flag.__state_ != ~0ul)
+    {
+        __call_once_param<const _Callable> __p(__func);
+        __call_once(__flag.__state_, &__p, &__call_once_proxy<const _Callable>);
+    }
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_MUTEX

diff --git a/libcxx/include/new b/libcxx/include/new
new file mode 100644
index 0000000..d2b2ae6
--- /dev/null
+++ b/libcxx/include/new

@@ -0,0 +1,182 @@
+// -*- C++ -*-
+//===----------------------------- new ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_NEW
+#define _LIBCPP_NEW
+
+/*
+    new synopsis
+
+namespace std
+{
+
+class bad_alloc
+    : public exception
+{
+public:
+    bad_alloc() noexcept;
+    bad_alloc(const bad_alloc&) noexcept;
+    bad_alloc& operator=(const bad_alloc&) noexcept;
+    virtual const char* what() const noexcept;
+};
+
+class bad_array_length : public bad_alloc // C++14
+{
+public:
+    bad_array_length() noexcept;
+};
+
+class bad_array_new_length : public bad_alloc
+{
+public:
+    bad_array_new_length() noexcept;
+};
+
+struct nothrow_t {};
+extern const nothrow_t nothrow;
+typedef void (*new_handler)();
+new_handler set_new_handler(new_handler new_p) noexcept;
+new_handler get_new_handler() noexcept;
+
+}  // std
+
+void* operator new(std::size_t size);                                   // replaceable
+void* operator new(std::size_t size, const std::nothrow_t&) noexcept;   // replaceable
+void  operator delete(void* ptr) noexcept;                              // replaceable
+void  operator delete(void* ptr, std::size_t size) noexcept;            // replaceable, C++14
+void  operator delete(void* ptr, const std::nothrow_t&) noexcept;       // replaceable
+
+void* operator new[](std::size_t size);                                 // replaceable
+void* operator new[](std::size_t size, const std::nothrow_t&) noexcept; // replaceable
+void  operator delete[](void* ptr) noexcept;                            // replaceable
+void  operator delete[](void* ptr, std::size_t size) noexcept;          // replaceable, C++14
+void  operator delete[](void* ptr, const std::nothrow_t&) noexcept;     // replaceable
+
+void* operator new  (std::size_t size, void* ptr) noexcept;
+void* operator new[](std::size_t size, void* ptr) noexcept;
+void  operator delete  (void* ptr, void*) noexcept;
+void  operator delete[](void* ptr, void*) noexcept;
+
+*/
+
+#include <__config>
+#include <exception>
+#include <cstddef>
+
+#include <__undef___deallocate>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+namespace std  // purposefully not using versioning namespace
+{
+
+class _LIBCPP_EXCEPTION_ABI bad_alloc
+    : public exception
+{
+public:
+    bad_alloc() _NOEXCEPT;
+    virtual ~bad_alloc() _NOEXCEPT;
+    virtual const char* what() const _NOEXCEPT;
+};
+
+class _LIBCPP_EXCEPTION_ABI bad_array_new_length
+    : public bad_alloc
+{
+public:
+    bad_array_new_length() _NOEXCEPT;
+    virtual ~bad_array_new_length() _NOEXCEPT;
+    virtual const char* what() const _NOEXCEPT;
+};
+
+#if defined(_LIBCPP_BUILDING_NEW) || (_LIBCPP_STD_VER > 11)
+
+class _LIBCPP_EXCEPTION_ABI bad_array_length
+    : public bad_alloc
+{
+public:
+    bad_array_length() _NOEXCEPT;
+    virtual ~bad_array_length() _NOEXCEPT;
+    virtual const char* what() const _NOEXCEPT;
+};
+
+#define _LIBCPP_BAD_ARRAY_LENGTH_DEFINED
+
+#endif  // defined(_LIBCPP_BUILDING_NEW) || (_LIBCPP_STD_VER > 11)
+
+_LIBCPP_FUNC_VIS void __throw_bad_alloc();  // not in C++ spec
+
+struct _LIBCPP_TYPE_VIS nothrow_t {};
+extern _LIBCPP_FUNC_VIS const nothrow_t nothrow;
+typedef void (*new_handler)();
+_LIBCPP_FUNC_VIS new_handler set_new_handler(new_handler) _NOEXCEPT;
+_LIBCPP_FUNC_VIS new_handler get_new_handler() _NOEXCEPT;
+
+}  // std
+
+#if defined(_WIN32) && !defined(cxx_EXPORTS)
+# define _LIBCPP_NEW_DELETE_VIS _LIBCPP_FUNC_VIS_ONLY
+#else
+# define _LIBCPP_NEW_DELETE_VIS _LIBCPP_FUNC_VIS
+#endif
+
+_LIBCPP_NEW_DELETE_VIS void* operator new(std::size_t __sz)
+#if !__has_feature(cxx_noexcept)
+    throw(std::bad_alloc)
+#endif
+;
+_LIBCPP_NEW_DELETE_VIS void* operator new(std::size_t __sz, const std::nothrow_t&) _NOEXCEPT _NOALIAS;
+_LIBCPP_NEW_DELETE_VIS void  operator delete(void* __p) _NOEXCEPT;
+_LIBCPP_NEW_DELETE_VIS void  operator delete(void* __p, const std::nothrow_t&) _NOEXCEPT;
+#if defined(_LIBCPP_BUILDING_NEW) || _LIBCPP_STD_VER >= 14 || \
+    (defined(__cpp_sized_deallocation) && __cpp_sized_deallocation >= 201309)
+_LIBCPP_NEW_DELETE_VIS void  operator delete(void* __p, std::size_t __sz) _NOEXCEPT;
+#endif
+
+_LIBCPP_NEW_DELETE_VIS void* operator new[](std::size_t __sz)
+#if !__has_feature(cxx_noexcept)
+    throw(std::bad_alloc)
+#endif
+;
+_LIBCPP_NEW_DELETE_VIS void* operator new[](std::size_t __sz, const std::nothrow_t&) _NOEXCEPT _NOALIAS;
+_LIBCPP_NEW_DELETE_VIS void  operator delete[](void* __p) _NOEXCEPT;
+_LIBCPP_NEW_DELETE_VIS void  operator delete[](void* __p, const std::nothrow_t&) _NOEXCEPT;
+#if defined(_LIBCPP_BUILDING_NEW) || _LIBCPP_STD_VER >= 14 || \
+    (defined(__cpp_sized_deallocation) && __cpp_sized_deallocation >= 201309)
+_LIBCPP_NEW_DELETE_VIS void  operator delete[](void* __p, std::size_t __sz) _NOEXCEPT;
+#endif
+
+inline _LIBCPP_INLINE_VISIBILITY void* operator new  (std::size_t, void* __p) _NOEXCEPT {return __p;}
+inline _LIBCPP_INLINE_VISIBILITY void* operator new[](std::size_t, void* __p) _NOEXCEPT {return __p;}
+inline _LIBCPP_INLINE_VISIBILITY void  operator delete  (void*, void*) _NOEXCEPT {}
+inline _LIBCPP_INLINE_VISIBILITY void  operator delete[](void*, void*) _NOEXCEPT {}
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+inline _LIBCPP_INLINE_VISIBILITY void *__allocate(size_t __size) {
+#ifdef _LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE
+  return ::operator new(__size);
+#else
+  return __builtin_operator_new(__size);
+#endif
+}
+
+inline _LIBCPP_INLINE_VISIBILITY void __deallocate(void *__ptr) {
+#ifdef _LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE
+  ::operator delete(__ptr);
+#else
+  __builtin_operator_delete(__ptr);
+#endif
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_NEW

diff --git a/libcxx/include/numeric b/libcxx/include/numeric
new file mode 100644
index 0000000..21c3781
--- /dev/null
+++ b/libcxx/include/numeric

@@ -0,0 +1,197 @@
+// -*- C++ -*-
+//===---------------------------- numeric ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_NUMERIC
+#define _LIBCPP_NUMERIC
+
+/*
+    numeric synopsis
+
+namespace std
+{
+
+template <class InputIterator, class T>
+    T
+    accumulate(InputIterator first, InputIterator last, T init);
+
+template <class InputIterator, class T, class BinaryOperation>
+    T
+    accumulate(InputIterator first, InputIterator last, T init, BinaryOperation binary_op);
+
+template <class InputIterator1, class InputIterator2, class T>
+    T
+    inner_product(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, T init);
+
+template <class InputIterator1, class InputIterator2, class T, class BinaryOperation1, class BinaryOperation2>
+    T
+    inner_product(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2,
+                  T init, BinaryOperation1 binary_op1, BinaryOperation2 binary_op2);
+
+template <class InputIterator, class OutputIterator>
+    OutputIterator
+    partial_sum(InputIterator first, InputIterator last, OutputIterator result);
+
+template <class InputIterator, class OutputIterator, class BinaryOperation>
+    OutputIterator
+    partial_sum(InputIterator first, InputIterator last, OutputIterator result, BinaryOperation binary_op);
+
+template <class InputIterator, class OutputIterator>
+    OutputIterator
+    adjacent_difference(InputIterator first, InputIterator last, OutputIterator result);
+
+template <class InputIterator, class OutputIterator, class BinaryOperation>
+    OutputIterator
+    adjacent_difference(InputIterator first, InputIterator last, OutputIterator result, BinaryOperation binary_op);
+
+template <class ForwardIterator, class T>
+    void iota(ForwardIterator first, ForwardIterator last, T value);
+
+}  // std
+
+*/
+
+#include <__config>
+#include <iterator>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _InputIterator, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp
+accumulate(_InputIterator __first, _InputIterator __last, _Tp __init)
+{
+    for (; __first != __last; ++__first)
+        __init = __init + *__first;
+    return __init;
+}
+
+template <class _InputIterator, class _Tp, class _BinaryOperation>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp
+accumulate(_InputIterator __first, _InputIterator __last, _Tp __init, _BinaryOperation __binary_op)
+{
+    for (; __first != __last; ++__first)
+        __init = __binary_op(__init, *__first);
+    return __init;
+}
+
+template <class _InputIterator1, class _InputIterator2, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp
+inner_product(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _Tp __init)
+{
+    for (; __first1 != __last1; ++__first1, (void) ++__first2)
+        __init = __init + *__first1 * *__first2;
+    return __init;
+}
+
+template <class _InputIterator1, class _InputIterator2, class _Tp, class _BinaryOperation1, class _BinaryOperation2>
+inline _LIBCPP_INLINE_VISIBILITY
+_Tp
+inner_product(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2,
+              _Tp __init, _BinaryOperation1 __binary_op1, _BinaryOperation2 __binary_op2)
+{
+    for (; __first1 != __last1; ++__first1, (void) ++__first2)
+        __init = __binary_op1(__init, __binary_op2(*__first1, *__first2));
+    return __init;
+}
+
+template <class _InputIterator, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+partial_sum(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
+{
+    if (__first != __last)
+    {
+        typename iterator_traits<_InputIterator>::value_type __t(*__first);
+        *__result = __t;
+        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
+        {
+            __t = __t + *__first;
+            *__result = __t;
+        }
+    }
+    return __result;
+}
+
+template <class _InputIterator, class _OutputIterator, class _BinaryOperation>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+partial_sum(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
+              _BinaryOperation __binary_op)
+{
+    if (__first != __last)
+    {
+        typename iterator_traits<_InputIterator>::value_type __t(*__first);
+        *__result = __t;
+        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
+        {
+            __t = __binary_op(__t, *__first);
+            *__result = __t;
+        }
+    }
+    return __result;
+}
+
+template <class _InputIterator, class _OutputIterator>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+adjacent_difference(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
+{
+    if (__first != __last)
+    {
+        typename iterator_traits<_InputIterator>::value_type __t1(*__first);
+        *__result = __t1;
+        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
+        {
+            typename iterator_traits<_InputIterator>::value_type __t2(*__first);
+            *__result = __t2 - __t1;
+            __t1 = _VSTD::move(__t2);
+        }
+    }
+    return __result;
+}
+
+template <class _InputIterator, class _OutputIterator, class _BinaryOperation>
+inline _LIBCPP_INLINE_VISIBILITY
+_OutputIterator
+adjacent_difference(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
+                      _BinaryOperation __binary_op)
+{
+    if (__first != __last)
+    {
+        typename iterator_traits<_InputIterator>::value_type __t1(*__first);
+        *__result = __t1;
+        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
+        {
+            typename iterator_traits<_InputIterator>::value_type __t2(*__first);
+            *__result = __binary_op(__t2, __t1);
+            __t1 = _VSTD::move(__t2);
+        }
+    }
+    return __result;
+}
+
+template <class _ForwardIterator, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+iota(_ForwardIterator __first, _ForwardIterator __last, _Tp __value_)
+{
+    for (; __first != __last; ++__first, (void) ++__value_)
+        *__first = __value_;
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_NUMERIC

diff --git a/libcxx/include/ostream b/libcxx/include/ostream
new file mode 100644
index 0000000..f55fd40
--- /dev/null
+++ b/libcxx/include/ostream

@@ -0,0 +1,1113 @@
+// -*- C++ -*-
+//===-------------------------- ostream -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_OSTREAM
+#define _LIBCPP_OSTREAM
+
+/*
+    ostream synopsis
+
+template <class charT, class traits = char_traits<charT> >
+class basic_ostream
+    : virtual public basic_ios<charT,traits>
+{
+public:
+    // types (inherited from basic_ios (27.5.4)):
+    typedef charT                          char_type;
+    typedef traits                         traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    // 27.7.2.2 Constructor/destructor:
+    explicit basic_ostream(basic_streambuf<char_type,traits>* sb);
+    basic_ostream(basic_ostream&& rhs);
+    virtual ~basic_ostream();
+
+    // 27.7.2.3 Assign/swap
+    basic_ostream& operator=(const basic_ostream& rhs) = delete; // C++14
+    basic_ostream& operator=(basic_ostream&& rhs);
+    void swap(basic_ostream& rhs);
+
+    // 27.7.2.4 Prefix/suffix:
+    class sentry;
+
+    // 27.7.2.6 Formatted output:
+    basic_ostream& operator<<(basic_ostream& (*pf)(basic_ostream&));
+    basic_ostream& operator<<(basic_ios<charT, traits>& (*pf)(basic_ios<charT,traits>&));
+    basic_ostream& operator<<(ios_base& (*pf)(ios_base&));
+    basic_ostream& operator<<(bool n);
+    basic_ostream& operator<<(short n);
+    basic_ostream& operator<<(unsigned short n);
+    basic_ostream& operator<<(int n);
+    basic_ostream& operator<<(unsigned int n);
+    basic_ostream& operator<<(long n);
+    basic_ostream& operator<<(unsigned long n);
+    basic_ostream& operator<<(long long n);
+    basic_ostream& operator<<(unsigned long long n);
+    basic_ostream& operator<<(float f);
+    basic_ostream& operator<<(double f);
+    basic_ostream& operator<<(long double f);
+    basic_ostream& operator<<(const void* p);
+    basic_ostream& operator<<(basic_streambuf<char_type,traits>* sb);
+
+    // 27.7.2.7 Unformatted output:
+    basic_ostream& put(char_type c);
+    basic_ostream& write(const char_type* s, streamsize n);
+    basic_ostream& flush();
+
+    // 27.7.2.5 seeks:
+    pos_type tellp();
+    basic_ostream& seekp(pos_type);
+    basic_ostream& seekp(off_type, ios_base::seekdir);
+protected:
+    basic_ostream(const basic_ostream& rhs) = delete;
+    basic_ostream(basic_ostream&& rhs);
+    // 27.7.3.3 Assign/swap
+    basic_ostream& operator=(basic_ostream& rhs) = delete;
+    basic_ostream& operator=(const basic_ostream&& rhs);
+    void swap(basic_ostream& rhs);
+};
+
+// 27.7.2.6.4 character inserters
+
+template<class charT, class traits>
+  basic_ostream<charT,traits>& operator<<(basic_ostream<charT,traits>&, charT);
+
+template<class charT, class traits>
+  basic_ostream<charT,traits>& operator<<(basic_ostream<charT,traits>&, char);
+
+template<class traits>
+  basic_ostream<char,traits>& operator<<(basic_ostream<char,traits>&, char);
+
+// signed and unsigned
+
+template<class traits>
+  basic_ostream<char,traits>& operator<<(basic_ostream<char,traits>&, signed char);
+
+template<class traits>
+  basic_ostream<char,traits>& operator<<(basic_ostream<char,traits>&, unsigned char);
+
+// NTBS
+template<class charT, class traits>
+  basic_ostream<charT,traits>& operator<<(basic_ostream<charT,traits>&, const charT*);
+
+template<class charT, class traits>
+  basic_ostream<charT,traits>& operator<<(basic_ostream<charT,traits>&, const char*);
+
+template<class traits>
+  basic_ostream<char,traits>& operator<<(basic_ostream<char,traits>&, const char*);
+
+// signed and unsigned
+template<class traits>
+basic_ostream<char,traits>& operator<<(basic_ostream<char,traits>&, const signed char*);
+
+template<class traits>
+  basic_ostream<char,traits>& operator<<(basic_ostream<char,traits>&, const unsigned char*);
+
+// swap:
+template <class charT, class traits>
+  void swap(basic_ostream<charT, traits>& x, basic_ostream<charT, traits>& y);
+
+template <class charT, class traits>
+  basic_ostream<charT,traits>& endl(basic_ostream<charT,traits>& os);
+
+template <class charT, class traits>
+  basic_ostream<charT,traits>& ends(basic_ostream<charT,traits>& os);
+
+template <class charT, class traits>
+  basic_ostream<charT,traits>& flush(basic_ostream<charT,traits>& os);
+
+// rvalue stream insertion
+template <class charT, class traits, class T>
+  basic_ostream<charT, traits>&
+  operator<<(basic_ostream<charT, traits>&& os, const T& x);
+
+}  // std
+
+*/
+
+#include <__config>
+#include <ios>
+#include <streambuf>
+#include <locale>
+#include <iterator>
+#include <bitset>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TYPE_VIS_ONLY basic_ostream
+    : virtual public basic_ios<_CharT, _Traits>
+{
+public:
+    // types (inherited from basic_ios (27.5.4)):
+    typedef _CharT                         char_type;
+    typedef _Traits                        traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    // 27.7.2.2 Constructor/destructor:
+    explicit basic_ostream(basic_streambuf<char_type, traits_type>* __sb);
+    virtual ~basic_ostream();
+protected:
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    basic_ostream(basic_ostream&& __rhs);
+#endif
+
+    // 27.7.2.3 Assign/swap
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    basic_ostream& operator=(basic_ostream&& __rhs);
+#endif
+    void swap(basic_ostream& __rhs);
+
+#ifndef _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+    basic_ostream           (const basic_ostream& __rhs) = delete;
+    basic_ostream& operator=(const basic_ostream& __rhs) = delete;
+#else
+    basic_ostream           (const basic_ostream& __rhs); // not defined
+    basic_ostream& operator=(const basic_ostream& __rhs); // not defined
+#endif
+public:
+
+    // 27.7.2.4 Prefix/suffix:
+    class _LIBCPP_TYPE_VIS_ONLY sentry;
+
+    // 27.7.2.6 Formatted output:
+    basic_ostream& operator<<(basic_ostream& (*__pf)(basic_ostream&));
+    basic_ostream& operator<<(basic_ios<char_type, traits_type>&
+                              (*__pf)(basic_ios<char_type,traits_type>&));
+    basic_ostream& operator<<(ios_base& (*__pf)(ios_base&));
+    basic_ostream& operator<<(bool __n);
+    basic_ostream& operator<<(short __n);
+    basic_ostream& operator<<(unsigned short __n);
+    basic_ostream& operator<<(int __n);
+    basic_ostream& operator<<(unsigned int __n);
+    basic_ostream& operator<<(long __n);
+    basic_ostream& operator<<(unsigned long __n);
+    basic_ostream& operator<<(long long __n);
+    basic_ostream& operator<<(unsigned long long __n);
+    basic_ostream& operator<<(float __f);
+    basic_ostream& operator<<(double __f);
+    basic_ostream& operator<<(long double __f);
+    basic_ostream& operator<<(const void* __p);
+    basic_ostream& operator<<(basic_streambuf<char_type, traits_type>* __sb);
+
+    // 27.7.2.7 Unformatted output:
+    basic_ostream& put(char_type __c);
+    basic_ostream& write(const char_type* __s, streamsize __n);
+    basic_ostream& flush();
+
+    // 27.7.2.5 seeks:
+    pos_type tellp();
+    basic_ostream& seekp(pos_type __pos);
+    basic_ostream& seekp(off_type __off, ios_base::seekdir __dir);
+
+protected:
+    _LIBCPP_ALWAYS_INLINE
+    basic_ostream() {}  // extension, intentially does not initialize
+};
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TYPE_VIS_ONLY basic_ostream<_CharT, _Traits>::sentry
+{
+    bool __ok_;
+    basic_ostream<_CharT, _Traits>& __os_;
+
+    sentry(const sentry&); // = delete;
+    sentry& operator=(const sentry&); // = delete;
+
+public:
+    explicit sentry(basic_ostream<_CharT, _Traits>& __os);
+    ~sentry();
+
+    _LIBCPP_ALWAYS_INLINE
+        _LIBCPP_EXPLICIT
+        operator bool() const {return __ok_;}
+};
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>::sentry::sentry(basic_ostream<_CharT, _Traits>& __os)
+    : __ok_(false),
+      __os_(__os)
+{
+    if (__os.good())
+    {
+        if (__os.tie())
+            __os.tie()->flush();
+        __ok_ = true;
+    }
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>::sentry::~sentry()
+{
+    if (__os_.rdbuf() && __os_.good() && (__os_.flags() & ios_base::unitbuf)
+                      && !uncaught_exception())
+    {
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        try
+        {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            if (__os_.rdbuf()->pubsync() == -1)
+                __os_.setstate(ios_base::badbit);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+        }
+        catch (...)
+        {
+        }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    }
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>::basic_ostream(basic_streambuf<char_type, traits_type>* __sb)
+{
+    this->init(__sb);
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>::basic_ostream(basic_ostream&& __rhs)
+{
+    this->move(__rhs);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator=(basic_ostream&& __rhs)
+{
+    swap(__rhs);
+    return *this;
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>::~basic_ostream()
+{
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+basic_ostream<_CharT, _Traits>::swap(basic_ostream& __rhs)
+{
+    basic_ios<char_type, traits_type>::swap(__rhs);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(basic_ostream& (*__pf)(basic_ostream&))
+{
+    return __pf(*this);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(basic_ios<char_type, traits_type>&
+                                           (*__pf)(basic_ios<char_type,traits_type>&))
+{
+    __pf(*this);
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(ios_base& (*__pf)(ios_base&))
+{
+    __pf(*this);
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(basic_streambuf<char_type, traits_type>* __sb)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            if (__sb)
+            {
+#ifndef _LIBCPP_NO_EXCEPTIONS
+                try
+                {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+                    typedef istreambuf_iterator<_CharT, _Traits> _Ip;
+                    typedef ostreambuf_iterator<_CharT, _Traits> _Op;
+                    _Ip __i(__sb);
+                    _Ip __eof;
+                    _Op __o(*this);
+                    size_t __c = 0;
+                    for (; __i != __eof; ++__i, ++__o, ++__c)
+                    {
+                        *__o = *__i;
+                        if (__o.failed())
+                            break;
+                    }
+                    if (__c == 0)
+                        this->setstate(ios_base::failbit);
+#ifndef _LIBCPP_NO_EXCEPTIONS
+                }
+                catch (...)
+                {
+                    this->__set_failbit_and_consider_rethrow();
+                }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+            }
+            else
+                this->setstate(ios_base::badbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(bool __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
+            const _Fp& __f = use_facet<_Fp>(this->getloc());
+            if (__f.put(*this, *this, this->fill(), __n).failed())
+                this->setstate(ios_base::badbit | ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(short __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            ios_base::fmtflags __flags = ios_base::flags() & ios_base::basefield;
+            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
+            const _Fp& __f = use_facet<_Fp>(this->getloc());
+            if (__f.put(*this, *this, this->fill(),
+                        __flags == ios_base::oct || __flags == ios_base::hex ?
+                        static_cast<long>(static_cast<unsigned short>(__n))  :
+                        static_cast<long>(__n)).failed())
+                this->setstate(ios_base::badbit | ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(unsigned short __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
+            const _Fp& __f = use_facet<_Fp>(this->getloc());
+            if (__f.put(*this, *this, this->fill(), static_cast<unsigned long>(__n)).failed())
+                this->setstate(ios_base::badbit | ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(int __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            ios_base::fmtflags __flags = ios_base::flags() & ios_base::basefield;
+            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
+            const _Fp& __f = use_facet<_Fp>(this->getloc());
+            if (__f.put(*this, *this, this->fill(),
+                        __flags == ios_base::oct || __flags == ios_base::hex ?
+                        static_cast<long>(static_cast<unsigned int>(__n))  :
+                        static_cast<long>(__n)).failed())
+                this->setstate(ios_base::badbit | ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(unsigned int __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
+            const _Fp& __f = use_facet<_Fp>(this->getloc());
+            if (__f.put(*this, *this, this->fill(), static_cast<unsigned long>(__n)).failed())
+                this->setstate(ios_base::badbit | ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(long __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
+            const _Fp& __f = use_facet<_Fp>(this->getloc());
+            if (__f.put(*this, *this, this->fill(), __n).failed())
+                this->setstate(ios_base::badbit | ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(unsigned long __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
+            const _Fp& __f = use_facet<_Fp>(this->getloc());
+            if (__f.put(*this, *this, this->fill(), __n).failed())
+                this->setstate(ios_base::badbit | ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(long long __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
+            const _Fp& __f = use_facet<_Fp>(this->getloc());
+            if (__f.put(*this, *this, this->fill(), __n).failed())
+                this->setstate(ios_base::badbit | ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(unsigned long long __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
+            const _Fp& __f = use_facet<_Fp>(this->getloc());
+            if (__f.put(*this, *this, this->fill(), __n).failed())
+                this->setstate(ios_base::badbit | ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(float __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
+            const _Fp& __f = use_facet<_Fp>(this->getloc());
+            if (__f.put(*this, *this, this->fill(), static_cast<double>(__n)).failed())
+                this->setstate(ios_base::badbit | ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(double __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
+            const _Fp& __f = use_facet<_Fp>(this->getloc());
+            if (__f.put(*this, *this, this->fill(), __n).failed())
+                this->setstate(ios_base::badbit | ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(long double __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
+            const _Fp& __f = use_facet<_Fp>(this->getloc());
+            if (__f.put(*this, *this, this->fill(), __n).failed())
+                this->setstate(ios_base::badbit | ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::operator<<(const void* __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
+            const _Fp& __f = use_facet<_Fp>(this->getloc());
+            if (__f.put(*this, *this, this->fill(), __n).failed())
+                this->setstate(ios_base::badbit | ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template<class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+__put_character_sequence(basic_ostream<_CharT, _Traits>& __os,
+                          const _CharT* __str, size_t __len)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typename basic_ostream<_CharT, _Traits>::sentry __s(__os);
+        if (__s)
+        {
+            typedef ostreambuf_iterator<_CharT, _Traits> _Ip;
+            if (__pad_and_output(_Ip(__os),
+                                 __str,
+                                 (__os.flags() & ios_base::adjustfield) == ios_base::left ?
+                                     __str + __len :
+                                     __str,
+                                 __str + __len,
+                                 __os,
+                                 __os.fill()).failed())
+                __os.setstate(ios_base::badbit | ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __os.__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __os;
+}
+
+
+template<class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os, _CharT __c)
+{
+    return _VSTD::__put_character_sequence(__os, &__c, 1);
+}
+
+template<class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os, char __cn)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typename basic_ostream<_CharT, _Traits>::sentry __s(__os);
+        if (__s)
+        {
+            _CharT __c = __os.widen(__cn);
+            typedef ostreambuf_iterator<_CharT, _Traits> _Ip;
+            if (__pad_and_output(_Ip(__os),
+                                 &__c,
+                                 (__os.flags() & ios_base::adjustfield) == ios_base::left ?
+                                     &__c + 1 :
+                                     &__c,
+                                 &__c + 1,
+                                 __os,
+                                 __os.fill()).failed())
+                __os.setstate(ios_base::badbit | ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __os.__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __os;
+}
+
+template<class _Traits>
+basic_ostream<char, _Traits>&
+operator<<(basic_ostream<char, _Traits>& __os, char __c)
+{
+    return _VSTD::__put_character_sequence(__os, &__c, 1);
+}
+
+template<class _Traits>
+basic_ostream<char, _Traits>&
+operator<<(basic_ostream<char, _Traits>& __os, signed char __c)
+{
+    return _VSTD::__put_character_sequence(__os, (char *) &__c, 1);
+}
+
+template<class _Traits>
+basic_ostream<char, _Traits>&
+operator<<(basic_ostream<char, _Traits>& __os, unsigned char __c)
+{
+    return _VSTD::__put_character_sequence(__os, (char *) &__c, 1);
+}
+
+template<class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os, const _CharT* __str)
+{
+    return _VSTD::__put_character_sequence(__os, __str, _Traits::length(__str));
+}
+
+template<class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os, const char* __strn)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        typename basic_ostream<_CharT, _Traits>::sentry __s(__os);
+        if (__s)
+        {
+            typedef ostreambuf_iterator<_CharT, _Traits> _Ip;
+            size_t __len = char_traits<char>::length(__strn);
+            const int __bs = 100;
+            _CharT __wbb[__bs];
+            _CharT* __wb = __wbb;
+            unique_ptr<_CharT, void(*)(void*)> __h(0, free);
+            if (__len > __bs)
+            {
+                __wb = (_CharT*)malloc(__len*sizeof(_CharT));
+                if (__wb == 0)
+                    __throw_bad_alloc();
+                __h.reset(__wb);
+            }
+            for (_CharT* __p = __wb; *__strn != '\0'; ++__strn, ++__p)
+                *__p = __os.widen(*__strn);
+            if (__pad_and_output(_Ip(__os),
+                                 __wb,
+                                 (__os.flags() & ios_base::adjustfield) == ios_base::left ?
+                                     __wb + __len :
+                                     __wb,
+                                 __wb + __len,
+                                 __os,
+                                 __os.fill()).failed())
+                __os.setstate(ios_base::badbit | ios_base::failbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        __os.__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return __os;
+}
+
+template<class _Traits>
+basic_ostream<char, _Traits>&
+operator<<(basic_ostream<char, _Traits>& __os, const char* __str)
+{
+    return _VSTD::__put_character_sequence(__os, __str, _Traits::length(__str));
+}
+
+template<class _Traits>
+basic_ostream<char, _Traits>&
+operator<<(basic_ostream<char, _Traits>& __os, const signed char* __str)
+{
+    const char *__s = (const char *) __str;
+    return _VSTD::__put_character_sequence(__os, __s, _Traits::length(__s));
+}
+
+template<class _Traits>
+basic_ostream<char, _Traits>&
+operator<<(basic_ostream<char, _Traits>& __os, const unsigned char* __str)
+{
+    const char *__s = (const char *) __str;
+    return _VSTD::__put_character_sequence(__os, __s, _Traits::length(__s));
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::put(char_type __c)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __s(*this);
+        if (__s)
+        {
+            typedef ostreambuf_iterator<_CharT, _Traits> _Op;
+            _Op __o(*this);
+            *__o = __c;
+            if (__o.failed())
+                this->setstate(ios_base::badbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::write(const char_type* __s, streamsize __n)
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        sentry __sen(*this);
+        if (__sen && __n)
+        {
+            if (this->rdbuf()->sputn(__s, __n) != __n)
+                this->setstate(ios_base::badbit);
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::flush()
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif  // _LIBCPP_NO_EXCEPTIONS
+        if (this->rdbuf())
+        {
+            sentry __s(*this);
+            if (__s)
+            {
+                if (this->rdbuf()->pubsync() == -1)
+                    this->setstate(ios_base::badbit);
+            }
+        }
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+        this->__set_badbit_and_consider_rethrow();
+    }
+#endif  // _LIBCPP_NO_EXCEPTIONS
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+typename basic_ostream<_CharT, _Traits>::pos_type
+basic_ostream<_CharT, _Traits>::tellp()
+{
+    if (this->fail())
+        return pos_type(-1);
+    return this->rdbuf()->pubseekoff(0, ios_base::cur, ios_base::out);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::seekp(pos_type __pos)
+{
+    sentry __s(*this);
+    if (!this->fail())
+    {
+        if (this->rdbuf()->pubseekpos(__pos, ios_base::out) == pos_type(-1))
+            this->setstate(ios_base::failbit);
+    }
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>&
+basic_ostream<_CharT, _Traits>::seekp(off_type __off, ios_base::seekdir __dir)
+{
+    sentry __s(*this);
+    if (!this->fail())
+    {
+        if (this->rdbuf()->pubseekoff(__off, __dir, ios_base::out) == pos_type(-1))
+            this->setstate(ios_base::failbit);
+    }
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>&
+endl(basic_ostream<_CharT, _Traits>& __os)
+{
+    __os.put(__os.widen('\n'));
+    __os.flush();
+    return __os;
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>&
+ends(basic_ostream<_CharT, _Traits>& __os)
+{
+    __os.put(_CharT());
+    return __os;
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>&
+flush(basic_ostream<_CharT, _Traits>& __os)
+{
+    __os.flush();
+    return __os;
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Stream, class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+typename enable_if
+<
+    !is_lvalue_reference<_Stream>::value &&
+    is_base_of<ios_base, _Stream>::value,
+    _Stream&&
+>::type
+operator<<(_Stream&& __os, const _Tp& __x)
+{
+    __os << __x;
+    return _VSTD::move(__os);
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template<class _CharT, class _Traits, class _Allocator>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os,
+           const basic_string<_CharT, _Traits, _Allocator>& __str)
+{
+    return _VSTD::__put_character_sequence(__os, __str.data(), __str.size());
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os, const error_code& __ec)
+{
+    return __os << __ec.category().name() << ':' << __ec.value();
+}
+
+template<class _CharT, class _Traits, class _Yp>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p)
+{
+    return __os << __p.get();
+}
+
+template <class _CharT, class _Traits, size_t _Size>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os, const bitset<_Size>& __x)
+{
+    return __os << __x.template to_string<_CharT, _Traits>
+                        (use_facet<ctype<_CharT> >(__os.getloc()).widen('0'),
+                         use_facet<ctype<_CharT> >(__os.getloc()).widen('1'));
+}
+
+_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_TYPE_VIS basic_ostream<char>)
+_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_TYPE_VIS basic_ostream<wchar_t>)
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_OSTREAM

diff --git a/libcxx/include/queue b/libcxx/include/queue
new file mode 100644
index 0000000..6f49c87
--- /dev/null
+++ b/libcxx/include/queue

@@ -0,0 +1,717 @@
+// -*- C++ -*-
+//===--------------------------- queue ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_QUEUE
+#define _LIBCPP_QUEUE
+
+/*
+    queue synopsis
+
+namespace std
+{
+
+template <class T, class Container = deque<T>>
+class queue
+{
+public:
+    typedef Container                                container_type;
+    typedef typename container_type::value_type      value_type;
+    typedef typename container_type::reference       reference;
+    typedef typename container_type::const_reference const_reference;
+    typedef typename container_type::size_type       size_type;
+
+protected:
+    container_type c;
+
+public:
+    queue() = default;
+    ~queue() = default;
+
+    queue(const queue& q) = default;
+    queue(queue&& q) = default;
+
+    queue& operator=(const queue& q) = default;
+    queue& operator=(queue&& q) = default;
+
+    explicit queue(const container_type& c);
+    explicit queue(container_type&& c)
+    template <class Alloc>
+        explicit queue(const Alloc& a);
+    template <class Alloc>
+        queue(const container_type& c, const Alloc& a);
+    template <class Alloc>
+        queue(container_type&& c, const Alloc& a);
+    template <class Alloc>
+        queue(const queue& q, const Alloc& a);
+    template <class Alloc>
+        queue(queue&& q, const Alloc& a);
+
+    bool      empty() const;
+    size_type size() const;
+
+    reference       front();
+    const_reference front() const;
+    reference       back();
+    const_reference back() const;
+
+    void push(const value_type& v);
+    void push(value_type&& v);
+    template <class... Args> void emplace(Args&&... args);
+    void pop();
+
+    void swap(queue& q) noexcept(noexcept(swap(c, q.c)));
+};
+
+template <class T, class Container>
+  bool operator==(const queue<T, Container>& x,const queue<T, Container>& y);
+
+template <class T, class Container>
+  bool operator< (const queue<T, Container>& x,const queue<T, Container>& y);
+
+template <class T, class Container>
+  bool operator!=(const queue<T, Container>& x,const queue<T, Container>& y);
+
+template <class T, class Container>
+  bool operator> (const queue<T, Container>& x,const queue<T, Container>& y);
+
+template <class T, class Container>
+  bool operator>=(const queue<T, Container>& x,const queue<T, Container>& y);
+
+template <class T, class Container>
+  bool operator<=(const queue<T, Container>& x,const queue<T, Container>& y);
+
+template <class T, class Container>
+  void swap(queue<T, Container>& x, queue<T, Container>& y)
+  noexcept(noexcept(x.swap(y)));
+
+template <class T, class Container = vector<T>,
+          class Compare = less<typename Container::value_type>>
+class priority_queue
+{
+public:
+    typedef Container                                container_type;
+    typedef typename container_type::value_type      value_type;
+    typedef typename container_type::reference       reference;
+    typedef typename container_type::const_reference const_reference;
+    typedef typename container_type::size_type       size_type;
+
+protected:
+    container_type c;
+    Compare comp;
+
+public:
+    priority_queue() = default;
+    ~priority_queue() = default;
+
+    priority_queue(const priority_queue& q) = default;
+    priority_queue(priority_queue&& q) = default;
+
+    priority_queue& operator=(const priority_queue& q) = default;
+    priority_queue& operator=(priority_queue&& q) = default;
+
+    explicit priority_queue(const Compare& comp);
+    priority_queue(const Compare& comp, const container_type& c);
+    explicit priority_queue(const Compare& comp, container_type&& c);
+    template <class InputIterator>
+        priority_queue(InputIterator first, InputIterator last,
+                       const Compare& comp = Compare());
+    template <class InputIterator>
+        priority_queue(InputIterator first, InputIterator last,
+                       const Compare& comp, const container_type& c);
+    template <class InputIterator>
+        priority_queue(InputIterator first, InputIterator last,
+                       const Compare& comp, container_type&& c);
+    template <class Alloc>
+        explicit priority_queue(const Alloc& a);
+    template <class Alloc>
+        priority_queue(const Compare& comp, const Alloc& a);
+    template <class Alloc>
+        priority_queue(const Compare& comp, const container_type& c,
+                       const Alloc& a);
+    template <class Alloc>
+        priority_queue(const Compare& comp, container_type&& c,
+                       const Alloc& a);
+    template <class Alloc>
+        priority_queue(const priority_queue& q, const Alloc& a);
+    template <class Alloc>
+        priority_queue(priority_queue&& q, const Alloc& a);
+
+    bool            empty() const;
+    size_type       size() const;
+    const_reference top() const;
+
+    void push(const value_type& v);
+    void push(value_type&& v);
+    template <class... Args> void emplace(Args&&... args);
+    void pop();
+
+    void swap(priority_queue& q)
+        noexcept(noexcept(swap(c, q.c)) && noexcept(swap(comp.q.comp)));
+};
+
+template <class T, class Container, class Compare>
+  void swap(priority_queue<T, Container, Compare>& x,
+            priority_queue<T, Container, Compare>& y)
+            noexcept(noexcept(x.swap(y)));
+
+}  // std
+
+*/
+
+#include <__config>
+#include <deque>
+#include <vector>
+#include <functional>
+#include <algorithm>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Tp, class _Container = deque<_Tp> > class _LIBCPP_TYPE_VIS_ONLY queue;
+
+template <class _Tp, class _Container>
+_LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y);
+
+template <class _Tp, class _Container>
+_LIBCPP_INLINE_VISIBILITY
+bool
+operator< (const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y);
+
+template <class _Tp, class _Container /*= deque<_Tp>*/>
+class _LIBCPP_TYPE_VIS_ONLY queue
+{
+public:
+    typedef _Container                               container_type;
+    typedef typename container_type::value_type      value_type;
+    typedef typename container_type::reference       reference;
+    typedef typename container_type::const_reference const_reference;
+    typedef typename container_type::size_type       size_type;
+
+protected:
+    container_type c;
+
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    queue()
+        _NOEXCEPT_(is_nothrow_default_constructible<container_type>::value)
+        : c() {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    queue(const queue& __q) : c(__q.c) {}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    queue(queue&& __q)
+        _NOEXCEPT_(is_nothrow_move_constructible<container_type>::value)
+        : c(_VSTD::move(__q.c)) {}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY
+    queue& operator=(const queue& __q) {c = __q.c; return *this;}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    queue& operator=(queue&& __q)
+        _NOEXCEPT_(is_nothrow_move_assignable<container_type>::value)
+        {c = _VSTD::move(__q.c); return *this;}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit queue(const container_type& __c)  : c(__c) {}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    explicit queue(container_type&& __c) : c(_VSTD::move(__c)) {}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template <class _Alloc>
+        _LIBCPP_INLINE_VISIBILITY
+        explicit queue(const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type* = 0)
+            : c(__a) {}
+    template <class _Alloc>
+        _LIBCPP_INLINE_VISIBILITY
+        queue(const queue& __q, const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type* = 0)
+            : c(__q.c, __a) {}
+    template <class _Alloc>
+        _LIBCPP_INLINE_VISIBILITY
+        queue(const container_type& __c, const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type* = 0)
+            : c(__c, __a) {}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template <class _Alloc>
+        _LIBCPP_INLINE_VISIBILITY
+        queue(container_type&& __c, const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type* = 0)
+            : c(_VSTD::move(__c), __a) {}
+    template <class _Alloc>
+        _LIBCPP_INLINE_VISIBILITY
+        queue(queue&& __q, const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type* = 0)
+            : c(_VSTD::move(__q.c), __a) {}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool      empty() const {return c.empty();}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type size() const  {return c.size();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    reference       front()       {return c.front();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reference front() const {return c.front();}
+    _LIBCPP_INLINE_VISIBILITY
+    reference       back()        {return c.back();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reference back() const  {return c.back();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void push(const value_type& __v) {c.push_back(__v);}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    void push(value_type&& __v)      {c.push_back(_VSTD::move(__v));}
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    template <class... _Args>
+        _LIBCPP_INLINE_VISIBILITY
+        void emplace(_Args&&... __args)
+            {c.emplace_back(_VSTD::forward<_Args>(__args)...);}
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    void pop() {c.pop_front();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(queue& __q)
+        _NOEXCEPT_(__is_nothrow_swappable<container_type>::value)
+    {
+        using _VSTD::swap;
+        swap(c, __q.c);
+    }
+
+    template <class _T1, class _C1>
+    friend
+    _LIBCPP_INLINE_VISIBILITY
+    bool
+    operator==(const queue<_T1, _C1>& __x,const queue<_T1, _C1>& __y);
+
+    template <class _T1, class _C1>
+    friend
+    _LIBCPP_INLINE_VISIBILITY
+    bool
+    operator< (const queue<_T1, _C1>& __x,const queue<_T1, _C1>& __y);
+};
+
+template <class _Tp, class _Container>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
+{
+    return __x.c == __y.c;
+}
+
+template <class _Tp, class _Container>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator< (const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
+{
+    return __x.c < __y.c;
+}
+
+template <class _Tp, class _Container>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
+{
+    return !(__x == __y);
+}
+
+template <class _Tp, class _Container>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator> (const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
+{
+    return __y < __x;
+}
+
+template <class _Tp, class _Container>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator>=(const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
+{
+    return !(__x < __y);
+}
+
+template <class _Tp, class _Container>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator<=(const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
+{
+    return !(__y < __x);
+}
+
+template <class _Tp, class _Container>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(queue<_Tp, _Container>& __x, queue<_Tp, _Container>& __y)
+    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
+{
+    __x.swap(__y);
+}
+
+template <class _Tp, class _Container, class _Alloc>
+struct _LIBCPP_TYPE_VIS_ONLY uses_allocator<queue<_Tp, _Container>, _Alloc>
+    : public uses_allocator<_Container, _Alloc>
+{
+};
+
+template <class _Tp, class _Container = vector<_Tp>,
+          class _Compare = less<typename _Container::value_type> >
+class _LIBCPP_TYPE_VIS_ONLY priority_queue
+{
+public:
+    typedef _Container                               container_type;
+    typedef _Compare                                 value_compare;
+    typedef typename container_type::value_type      value_type;
+    typedef typename container_type::reference       reference;
+    typedef typename container_type::const_reference const_reference;
+    typedef typename container_type::size_type       size_type;
+
+protected:
+    container_type c;
+    value_compare comp;
+
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    priority_queue()
+        _NOEXCEPT_(is_nothrow_default_constructible<container_type>::value &&
+                   is_nothrow_default_constructible<value_compare>::value)
+        : c(), comp() {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    priority_queue(const priority_queue& __q) : c(__q.c), comp(__q.comp) {}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    priority_queue(priority_queue&& __q)
+        _NOEXCEPT_(is_nothrow_move_constructible<container_type>::value &&
+                   is_nothrow_move_constructible<value_compare>::value)
+        : c(_VSTD::move(__q.c)), comp(_VSTD::move(__q.comp)) {}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY
+    priority_queue& operator=(const priority_queue& __q)
+        {c = __q.c; comp = __q.comp; return *this;}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    priority_queue& operator=(priority_queue&& __q)
+        _NOEXCEPT_(is_nothrow_move_assignable<container_type>::value &&
+                   is_nothrow_move_assignable<value_compare>::value)
+        {c = _VSTD::move(__q.c); comp = _VSTD::move(__q.comp); return *this;}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit priority_queue(const value_compare& __comp)
+        : c(), comp(__comp) {}
+    priority_queue(const value_compare& __comp, const container_type& __c);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    explicit priority_queue(const value_compare& __comp, container_type&& __c);
+#endif
+    template <class _InputIter>
+        priority_queue(_InputIter __f, _InputIter __l,
+                       const value_compare& __comp = value_compare());
+    template <class _InputIter>
+        priority_queue(_InputIter __f, _InputIter __l,
+                       const value_compare& __comp, const container_type& __c);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template <class _InputIter>
+        priority_queue(_InputIter __f, _InputIter __l,
+                       const value_compare& __comp, container_type&& __c);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template <class _Alloc>
+        explicit priority_queue(const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type* = 0);
+    template <class _Alloc>
+        priority_queue(const value_compare& __comp, const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type* = 0);
+    template <class _Alloc>
+        priority_queue(const value_compare& __comp, const container_type& __c,
+                       const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type* = 0);
+    template <class _Alloc>
+        priority_queue(const priority_queue& __q, const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type* = 0);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    template <class _Alloc>
+        priority_queue(const value_compare& __comp, container_type&& __c,
+                       const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type* = 0);
+    template <class _Alloc>
+        priority_queue(priority_queue&& __q, const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type* = 0);
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+    _LIBCPP_INLINE_VISIBILITY
+    bool            empty() const {return c.empty();}
+    _LIBCPP_INLINE_VISIBILITY
+    size_type       size() const  {return c.size();}
+    _LIBCPP_INLINE_VISIBILITY
+    const_reference top() const   {return c.front();}
+
+    void push(const value_type& __v);
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    void push(value_type&& __v);
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+    template <class... _Args> void emplace(_Args&&... __args);
+#endif
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    void pop();
+
+    void swap(priority_queue& __q)
+        _NOEXCEPT_(__is_nothrow_swappable<container_type>::value &&
+                   __is_nothrow_swappable<value_compare>::value);
+};
+
+template <class _Tp, class _Container, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+priority_queue<_Tp, _Container, _Compare>::priority_queue(const _Compare& __comp,
+                                                          const container_type& __c)
+    : c(__c),
+      comp(__comp)
+{
+    _VSTD::make_heap(c.begin(), c.end(), comp);
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Container, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+priority_queue<_Tp, _Container, _Compare>::priority_queue(const value_compare& __comp,
+                                                          container_type&& __c)
+    : c(_VSTD::move(__c)),
+      comp(__comp)
+{
+    _VSTD::make_heap(c.begin(), c.end(), comp);
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Container, class _Compare>
+template <class _InputIter>
+inline _LIBCPP_INLINE_VISIBILITY
+priority_queue<_Tp, _Container, _Compare>::priority_queue(_InputIter __f, _InputIter __l,
+                                                          const value_compare& __comp)
+    : c(__f, __l),
+      comp(__comp)
+{
+    _VSTD::make_heap(c.begin(), c.end(), comp);
+}
+
+template <class _Tp, class _Container, class _Compare>
+template <class _InputIter>
+inline _LIBCPP_INLINE_VISIBILITY
+priority_queue<_Tp, _Container, _Compare>::priority_queue(_InputIter __f, _InputIter __l,
+                                                          const value_compare& __comp,
+                                                          const container_type& __c)
+    : c(__c),
+      comp(__comp)
+{
+    c.insert(c.end(), __f, __l);
+    _VSTD::make_heap(c.begin(), c.end(), comp);
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Container, class _Compare>
+template <class _InputIter>
+inline _LIBCPP_INLINE_VISIBILITY
+priority_queue<_Tp, _Container, _Compare>::priority_queue(_InputIter __f, _InputIter __l,
+                                                          const value_compare& __comp,
+                                                          container_type&& __c)
+    : c(_VSTD::move(__c)),
+      comp(__comp)
+{
+    c.insert(c.end(), __f, __l);
+    _VSTD::make_heap(c.begin(), c.end(), comp);
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Container, class _Compare>
+template <class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+priority_queue<_Tp, _Container, _Compare>::priority_queue(const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type*)
+    : c(__a)
+{
+}
+
+template <class _Tp, class _Container, class _Compare>
+template <class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+priority_queue<_Tp, _Container, _Compare>::priority_queue(const value_compare& __comp,
+                                                          const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type*)
+    : c(__a),
+      comp(__comp)
+{
+}
+
+template <class _Tp, class _Container, class _Compare>
+template <class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+priority_queue<_Tp, _Container, _Compare>::priority_queue(const value_compare& __comp,
+                                                          const container_type& __c,
+                                                          const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type*)
+    : c(__c, __a),
+      comp(__comp)
+{
+    _VSTD::make_heap(c.begin(), c.end(), comp);
+}
+
+template <class _Tp, class _Container, class _Compare>
+template <class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+priority_queue<_Tp, _Container, _Compare>::priority_queue(const priority_queue& __q,
+                                                          const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type*)
+    : c(__q.c, __a),
+      comp(__q.comp)
+{
+    _VSTD::make_heap(c.begin(), c.end(), comp);
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Container, class _Compare>
+template <class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+priority_queue<_Tp, _Container, _Compare>::priority_queue(const value_compare& __comp,
+                                                          container_type&& __c,
+                                                          const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type*)
+    : c(_VSTD::move(__c), __a),
+      comp(__comp)
+{
+    _VSTD::make_heap(c.begin(), c.end(), comp);
+}
+
+template <class _Tp, class _Container, class _Compare>
+template <class _Alloc>
+inline _LIBCPP_INLINE_VISIBILITY
+priority_queue<_Tp, _Container, _Compare>::priority_queue(priority_queue&& __q,
+                                                          const _Alloc& __a,
+                       typename enable_if<uses_allocator<container_type,
+                                                         _Alloc>::value>::type*)
+    : c(_VSTD::move(__q.c), __a),
+      comp(_VSTD::move(__q.comp))
+{
+    _VSTD::make_heap(c.begin(), c.end(), comp);
+}
+
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Container, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+priority_queue<_Tp, _Container, _Compare>::push(const value_type& __v)
+{
+    c.push_back(__v);
+    _VSTD::push_heap(c.begin(), c.end(), comp);
+}
+
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Container, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+priority_queue<_Tp, _Container, _Compare>::push(value_type&& __v)
+{
+    c.push_back(_VSTD::move(__v));
+    _VSTD::push_heap(c.begin(), c.end(), comp);
+}
+
+#ifndef _LIBCPP_HAS_NO_VARIADICS
+
+template <class _Tp, class _Container, class _Compare>
+template <class... _Args>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+priority_queue<_Tp, _Container, _Compare>::emplace(_Args&&... __args)
+{
+    c.emplace_back(_VSTD::forward<_Args>(__args)...);
+    _VSTD::push_heap(c.begin(), c.end(), comp);
+}
+
+#endif  // _LIBCPP_HAS_NO_VARIADICS
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+
+template <class _Tp, class _Container, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+priority_queue<_Tp, _Container, _Compare>::pop()
+{
+    _VSTD::pop_heap(c.begin(), c.end(), comp);
+    c.pop_back();
+}
+
+template <class _Tp, class _Container, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+priority_queue<_Tp, _Container, _Compare>::swap(priority_queue& __q)
+        _NOEXCEPT_(__is_nothrow_swappable<container_type>::value &&
+                   __is_nothrow_swappable<value_compare>::value)
+{
+    using _VSTD::swap;
+    swap(c, __q.c);
+    swap(comp, __q.comp);
+}
+
+template <class _Tp, class _Container, class _Compare>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(priority_queue<_Tp, _Container, _Compare>& __x,
+     priority_queue<_Tp, _Container, _Compare>& __y)
+    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
+{
+    __x.swap(__y);
+}
+
+template <class _Tp, class _Container, class _Compare, class _Alloc>
+struct _LIBCPP_TYPE_VIS_ONLY uses_allocator<priority_queue<_Tp, _Container, _Compare>, _Alloc>
+    : public uses_allocator<_Container, _Alloc>
+{
+};
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_QUEUE

diff --git a/libcxx/include/random b/libcxx/include/random
new file mode 100644
index 0000000..c8341ef
--- /dev/null
+++ b/libcxx/include/random

@@ -0,0 +1,6723 @@
+// -*- C++ -*-
+//===--------------------------- random -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_RANDOM
+#define _LIBCPP_RANDOM
+
+/*
+    random synopsis
+
+#include <initializer_list>
+
+namespace std
+{
+
+// Engines
+
+template <class UIntType, UIntType a, UIntType c, UIntType m>
+class linear_congruential_engine
+{
+public:
+    // types
+    typedef UIntType result_type;
+
+    // engine characteristics
+    static constexpr result_type multiplier = a;
+    static constexpr result_type increment = c;
+    static constexpr result_type modulus = m;
+    static constexpr result_type min() { return c == 0u ? 1u: 0u;}
+    static constexpr result_type max() { return m - 1u;}
+    static constexpr result_type default_seed = 1u;
+
+    // constructors and seeding functions
+    explicit linear_congruential_engine(result_type s = default_seed);
+    template<class Sseq> explicit linear_congruential_engine(Sseq& q);
+    void seed(result_type s = default_seed);
+    template<class Sseq> void seed(Sseq& q);
+
+    // generating functions
+    result_type operator()();
+    void discard(unsigned long long z);
+};
+
+template <class UIntType, UIntType a, UIntType c, UIntType m>
+bool
+operator==(const linear_congruential_engine<UIntType, a, c, m>& x,
+           const linear_congruential_engine<UIntType, a, c, m>& y);
+
+template <class UIntType, UIntType a, UIntType c, UIntType m>
+bool
+operator!=(const linear_congruential_engine<UIntType, a, c, m>& x,
+           const linear_congruential_engine<UIntType, a, c, m>& y);
+
+template <class charT, class traits,
+          class UIntType, UIntType a, UIntType c, UIntType m>
+basic_ostream<charT, traits>&
+operator<<(basic_ostream<charT, traits>& os,
+           const linear_congruential_engine<UIntType, a, c, m>& x);
+
+template <class charT, class traits,
+          class UIntType, UIntType a, UIntType c, UIntType m>
+basic_istream<charT, traits>&
+operator>>(basic_istream<charT, traits>& is,
+           linear_congruential_engine<UIntType, a, c, m>& x);
+
+template <class UIntType, size_t w, size_t n, size_t m, size_t r,
+          UIntType a, size_t u, UIntType d, size_t s,
+          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
+class mersenne_twister_engine
+{
+public:
+    // types
+    typedef UIntType result_type;
+
+    // engine characteristics
+    static constexpr size_t word_size = w;
+    static constexpr size_t state_size = n;
+    static constexpr size_t shift_size = m;
+    static constexpr size_t mask_bits = r;
+    static constexpr result_type xor_mask = a;
+    static constexpr size_t tempering_u = u;
+    static constexpr result_type tempering_d = d;
+    static constexpr size_t tempering_s = s;
+    static constexpr result_type tempering_b = b;
+    static constexpr size_t tempering_t = t;
+    static constexpr result_type tempering_c = c;
+    static constexpr size_t tempering_l = l;
+    static constexpr result_type initialization_multiplier = f;
+    static constexpr result_type min () { return 0; }
+    static constexpr result_type max() { return 2^w - 1; }
+    static constexpr result_type default_seed = 5489u;
+
+    // constructors and seeding functions
+    explicit mersenne_twister_engine(result_type value = default_seed);
+    template<class Sseq> explicit mersenne_twister_engine(Sseq& q);
+    void seed(result_type value = default_seed);
+    template<class Sseq> void seed(Sseq& q);
+
+    // generating functions
+    result_type operator()();
+    void discard(unsigned long long z);
+};
+
+template <class UIntType, size_t w, size_t n, size_t m, size_t r,
+          UIntType a, size_t u, UIntType d, size_t s,
+          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
+bool
+operator==(
+    const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& x,
+    const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& y);
+
+template <class UIntType, size_t w, size_t n, size_t m, size_t r,
+          UIntType a, size_t u, UIntType d, size_t s,
+          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
+bool
+operator!=(
+    const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& x,
+    const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& y);
+
+template <class charT, class traits,
+          class UIntType, size_t w, size_t n, size_t m, size_t r,
+          UIntType a, size_t u, UIntType d, size_t s,
+          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
+basic_ostream<charT, traits>&
+operator<<(basic_ostream<charT, traits>& os,
+           const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& x);
+
+template <class charT, class traits,
+          class UIntType, size_t w, size_t n, size_t m, size_t r,
+          UIntType a, size_t u, UIntType d, size_t s,
+          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
+basic_istream<charT, traits>&
+operator>>(basic_istream<charT, traits>& is,
+           mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& x);
+
+template<class UIntType, size_t w, size_t s, size_t r>
+class subtract_with_carry_engine
+{
+public:
+    // types
+    typedef UIntType result_type;
+
+    // engine characteristics
+    static constexpr size_t word_size = w;
+    static constexpr size_t short_lag = s;
+    static constexpr size_t long_lag = r;
+    static constexpr result_type min() { return 0; }
+    static constexpr result_type max() { return m-1; }
+    static constexpr result_type default_seed = 19780503u;
+
+    // constructors and seeding functions
+    explicit subtract_with_carry_engine(result_type value = default_seed);
+    template<class Sseq> explicit subtract_with_carry_engine(Sseq& q);
+    void seed(result_type value = default_seed);
+    template<class Sseq> void seed(Sseq& q);
+
+    // generating functions
+    result_type operator()();
+    void discard(unsigned long long z);
+};
+
+template<class UIntType, size_t w, size_t s, size_t r>
+bool
+operator==(
+    const subtract_with_carry_engine<UIntType, w, s, r>& x,
+    const subtract_with_carry_engine<UIntType, w, s, r>& y);
+
+template<class UIntType, size_t w, size_t s, size_t r>
+bool
+operator!=(
+    const subtract_with_carry_engine<UIntType, w, s, r>& x,
+    const subtract_with_carry_engine<UIntType, w, s, r>& y);
+
+template <class charT, class traits,
+          class UIntType, size_t w, size_t s, size_t r>
+basic_ostream<charT, traits>&
+operator<<(basic_ostream<charT, traits>& os,
+           const subtract_with_carry_engine<UIntType, w, s, r>& x);
+
+template <class charT, class traits,
+          class UIntType, size_t w, size_t s, size_t r>
+basic_istream<charT, traits>&
+operator>>(basic_istream<charT, traits>& is,
+           subtract_with_carry_engine<UIntType, w, s, r>& x);
+
+template<class Engine, size_t p, size_t r>
+class discard_block_engine
+{
+public:
+    // types
+    typedef typename Engine::result_type result_type;
+
+    // engine characteristics
+    static constexpr size_t block_size = p;
+    static constexpr size_t used_block = r;
+    static constexpr result_type min() { return Engine::min(); }
+    static constexpr result_type max() { return Engine::max(); }
+
+    // constructors and seeding functions
+    discard_block_engine();
+    explicit discard_block_engine(const Engine& e);
+    explicit discard_block_engine(Engine&& e);
+    explicit discard_block_engine(result_type s);
+    template<class Sseq> explicit discard_block_engine(Sseq& q);
+    void seed();
+    void seed(result_type s);
+    template<class Sseq> void seed(Sseq& q);
+
+    // generating functions
+    result_type operator()();
+    void discard(unsigned long long z);
+
+    // property functions
+    const Engine& base() const noexcept;
+};
+
+template<class Engine, size_t p, size_t r>
+bool
+operator==(
+    const discard_block_engine<Engine, p, r>& x,
+    const discard_block_engine<Engine, p, r>& y);
+
+template<class Engine, size_t p, size_t r>
+bool
+operator!=(
+    const discard_block_engine<Engine, p, r>& x,
+    const discard_block_engine<Engine, p, r>& y);
+
+template <class charT, class traits,
+          class Engine, size_t p, size_t r>
+basic_ostream<charT, traits>&
+operator<<(basic_ostream<charT, traits>& os,
+           const discard_block_engine<Engine, p, r>& x);
+
+template <class charT, class traits,
+          class Engine, size_t p, size_t r>
+basic_istream<charT, traits>&
+operator>>(basic_istream<charT, traits>& is,
+           discard_block_engine<Engine, p, r>& x);
+
+template<class Engine, size_t w, class UIntType>
+class independent_bits_engine
+{
+public:
+    // types
+    typedef UIntType result_type;
+
+    // engine characteristics
+    static constexpr result_type min() { return 0; }
+    static constexpr result_type max() { return 2^w - 1; }
+
+    // constructors and seeding functions
+    independent_bits_engine();
+    explicit independent_bits_engine(const Engine& e);
+    explicit independent_bits_engine(Engine&& e);
+    explicit independent_bits_engine(result_type s);
+    template<class Sseq> explicit independent_bits_engine(Sseq& q);
+    void seed();
+    void seed(result_type s);
+    template<class Sseq> void seed(Sseq& q);
+
+    // generating functions
+    result_type operator()(); void discard(unsigned long long z);
+
+    // property functions
+    const Engine& base() const noexcept;
+};
+
+template<class Engine, size_t w, class UIntType>
+bool
+operator==(
+    const independent_bits_engine<Engine, w, UIntType>& x,
+    const independent_bits_engine<Engine, w, UIntType>& y);
+
+template<class Engine, size_t w, class UIntType>
+bool
+operator!=(
+    const independent_bits_engine<Engine, w, UIntType>& x,
+    const independent_bits_engine<Engine, w, UIntType>& y);
+
+template <class charT, class traits,
+          class Engine, size_t w, class UIntType>
+basic_ostream<charT, traits>&
+operator<<(basic_ostream<charT, traits>& os,
+           const independent_bits_engine<Engine, w, UIntType>& x);
+
+template <class charT, class traits,
+          class Engine, size_t w, class UIntType>
+basic_istream<charT, traits>&
+operator>>(basic_istream<charT, traits>& is,
+           independent_bits_engine<Engine, w, UIntType>& x);
+
+template<class Engine, size_t k>
+class shuffle_order_engine
+{
+public:
+    // types
+    typedef typename Engine::result_type result_type;
+
+    // engine characteristics
+    static constexpr size_t table_size = k;
+    static constexpr result_type min() { return Engine::min; }
+    static constexpr result_type max() { return Engine::max; }
+
+    // constructors and seeding functions
+    shuffle_order_engine();
+    explicit shuffle_order_engine(const Engine& e);
+    explicit shuffle_order_engine(Engine&& e);
+    explicit shuffle_order_engine(result_type s);
+    template<class Sseq> explicit shuffle_order_engine(Sseq& q);
+    void seed();
+    void seed(result_type s);
+    template<class Sseq> void seed(Sseq& q);
+
+    // generating functions
+    result_type operator()();
+    void discard(unsigned long long z);
+
+    // property functions
+    const Engine& base() const noexcept;
+};
+
+template<class Engine, size_t k>
+bool
+operator==(
+    const shuffle_order_engine<Engine, k>& x,
+    const shuffle_order_engine<Engine, k>& y);
+
+template<class Engine, size_t k>
+bool
+operator!=(
+    const shuffle_order_engine<Engine, k>& x,
+    const shuffle_order_engine<Engine, k>& y);
+
+template <class charT, class traits,
+          class Engine, size_t k>
+basic_ostream<charT, traits>&
+operator<<(basic_ostream<charT, traits>& os,
+           const shuffle_order_engine<Engine, k>& x);
+
+template <class charT, class traits,
+          class Engine, size_t k>
+basic_istream<charT, traits>&
+operator>>(basic_istream<charT, traits>& is,
+           shuffle_order_engine<Engine, k>& x);
+
+typedef linear_congruential_engine<uint_fast32_t, 16807, 0, 2147483647>
+                                                                   minstd_rand0;
+typedef linear_congruential_engine<uint_fast32_t, 48271, 0, 2147483647>
+                                                                    minstd_rand;
+typedef mersenne_twister_engine<uint_fast32_t, 32, 624, 397, 31,
+                                0x9908b0df,
+                                11, 0xffffffff,
+                                7,  0x9d2c5680,
+                                15, 0xefc60000,
+                                18, 1812433253>                         mt19937;
+typedef mersenne_twister_engine<uint_fast64_t, 64, 312, 156, 31,
+                                0xb5026f5aa96619e9,
+                                29, 0x5555555555555555,
+                                17, 0x71d67fffeda60000,
+                                37, 0xfff7eee000000000,
+                                43, 6364136223846793005>             mt19937_64;
+typedef subtract_with_carry_engine<uint_fast32_t, 24, 10, 24>     ranlux24_base;
+typedef subtract_with_carry_engine<uint_fast64_t, 48,  5, 12>     ranlux48_base;
+typedef discard_block_engine<ranlux24_base, 223, 23>                   ranlux24;
+typedef discard_block_engine<ranlux48_base, 389, 11>                   ranlux48;
+typedef shuffle_order_engine<minstd_rand0, 256>                         knuth_b;
+typedef minstd_rand                                       default_random_engine;
+
+// Generators
+
+class random_device
+{
+public:
+    // types
+    typedef unsigned int result_type;
+
+    // generator characteristics
+    static constexpr result_type min() { return numeric_limits<result_type>::min(); }
+    static constexpr result_type max() { return numeric_limits<result_type>::max(); }
+
+    // constructors
+    explicit random_device(const string& token = "/dev/urandom");
+
+    // generating functions
+    result_type operator()();
+
+    // property functions
+    double entropy() const noexcept;
+
+    // no copy functions
+    random_device(const random_device& ) = delete;
+    void operator=(const random_device& ) = delete;
+};
+
+// Utilities
+
+class seed_seq
+{
+public:
+    // types
+    typedef uint_least32_t result_type;
+
+    // constructors
+    seed_seq();
+    template<class T>
+        seed_seq(initializer_list<T> il);
+    template<class InputIterator>
+        seed_seq(InputIterator begin, InputIterator end);
+
+    // generating functions
+    template<class RandomAccessIterator>
+        void generate(RandomAccessIterator begin, RandomAccessIterator end);
+
+    // property functions
+    size_t size() const;
+    template<class OutputIterator>
+        void param(OutputIterator dest) const;
+
+    // no copy functions
+    seed_seq(const seed_seq&) = delete;
+    void operator=(const seed_seq& ) = delete;
+};
+
+template<class RealType, size_t bits, class URNG>
+    RealType generate_canonical(URNG& g);
+
+// Distributions
+
+template<class IntType = int>
+class uniform_int_distribution
+{
+public:
+    // types
+    typedef IntType result_type;
+
+    class param_type
+    {
+    public:
+        typedef uniform_int_distribution distribution_type;
+
+        explicit param_type(IntType a = 0,
+                                    IntType b = numeric_limits<IntType>::max());
+
+        result_type a() const;
+        result_type b() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructors and reset functions
+    explicit uniform_int_distribution(IntType a = 0,
+                                    IntType b = numeric_limits<IntType>::max());
+    explicit uniform_int_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    result_type a() const;
+    result_type b() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const uniform_int_distribution& x,
+                           const uniform_int_distribution& y);
+    friend bool operator!=(const uniform_int_distribution& x,
+                           const uniform_int_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const uniform_int_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               uniform_int_distribution& x);
+};
+
+template<class RealType = double>
+class uniform_real_distribution
+{
+public:
+    // types
+    typedef RealType result_type;
+
+    class param_type
+    {
+    public:
+        typedef uniform_real_distribution distribution_type;
+
+        explicit param_type(RealType a = 0,
+                            RealType b = 1);
+
+        result_type a() const;
+        result_type b() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructors and reset functions
+    explicit uniform_real_distribution(RealType a = 0.0, RealType b = 1.0);
+    explicit uniform_real_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    result_type a() const;
+    result_type b() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const uniform_real_distribution& x,
+                           const uniform_real_distribution& y);
+    friend bool operator!=(const uniform_real_distribution& x,
+                           const uniform_real_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const uniform_real_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               uniform_real_distribution& x);
+};
+
+class bernoulli_distribution
+{
+public:
+    // types
+    typedef bool result_type;
+
+    class param_type
+    {
+    public:
+        typedef bernoulli_distribution distribution_type;
+
+        explicit param_type(double p = 0.5);
+
+        double p() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructors and reset functions
+    explicit bernoulli_distribution(double p = 0.5);
+    explicit bernoulli_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    double p() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const bernoulli_distribution& x,
+                           const bernoulli_distribution& y);
+    friend bool operator!=(const bernoulli_distribution& x,
+                           const bernoulli_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const bernoulli_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               bernoulli_distribution& x);
+};
+
+template<class IntType = int>
+class binomial_distribution
+{
+public:
+    // types
+    typedef IntType result_type;
+
+    class param_type
+    {
+    public:
+        typedef binomial_distribution distribution_type;
+
+        explicit param_type(IntType t = 1, double p = 0.5);
+
+        IntType t() const;
+        double p() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructors and reset functions
+    explicit binomial_distribution(IntType t = 1, double p = 0.5);
+    explicit binomial_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    IntType t() const;
+    double p() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const binomial_distribution& x,
+                           const binomial_distribution& y);
+    friend bool operator!=(const binomial_distribution& x,
+                           const binomial_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const binomial_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               binomial_distribution& x);
+};
+
+template<class IntType = int>
+class geometric_distribution
+{
+public:
+    // types
+    typedef IntType result_type;
+
+    class param_type
+    {
+    public:
+        typedef geometric_distribution distribution_type;
+
+        explicit param_type(double p = 0.5);
+
+        double p() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructors and reset functions
+    explicit geometric_distribution(double p = 0.5);
+    explicit geometric_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    double p() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const geometric_distribution& x,
+                           const geometric_distribution& y);
+    friend bool operator!=(const geometric_distribution& x,
+                           const geometric_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const geometric_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               geometric_distribution& x);
+};
+
+template<class IntType = int>
+class negative_binomial_distribution
+{
+public:
+    // types
+    typedef IntType result_type;
+
+    class param_type
+    {
+    public:
+        typedef negative_binomial_distribution distribution_type;
+
+        explicit param_type(result_type k = 1, double p = 0.5);
+
+        result_type k() const;
+        double p() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructor and reset functions
+    explicit negative_binomial_distribution(result_type k = 1, double p = 0.5);
+    explicit negative_binomial_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    result_type k() const;
+    double p() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const negative_binomial_distribution& x,
+                           const negative_binomial_distribution& y);
+    friend bool operator!=(const negative_binomial_distribution& x,
+                           const negative_binomial_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const negative_binomial_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               negative_binomial_distribution& x);
+};
+
+template<class IntType = int>
+class poisson_distribution
+{
+public:
+    // types
+    typedef IntType result_type;
+
+    class param_type
+    {
+    public:
+        typedef poisson_distribution distribution_type;
+
+        explicit param_type(double mean = 1.0);
+
+        double mean() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructors and reset functions
+    explicit poisson_distribution(double mean = 1.0);
+    explicit poisson_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    double mean() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const poisson_distribution& x,
+                           const poisson_distribution& y);
+    friend bool operator!=(const poisson_distribution& x,
+                           const poisson_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const poisson_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               poisson_distribution& x);
+};
+
+template<class RealType = double>
+class exponential_distribution
+{
+public:
+    // types
+    typedef RealType result_type;
+
+    class param_type
+    {
+    public:
+        typedef exponential_distribution distribution_type;
+
+        explicit param_type(result_type lambda = 1.0);
+
+        result_type lambda() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructors and reset functions
+    explicit exponential_distribution(result_type lambda = 1.0);
+    explicit exponential_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    result_type lambda() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const exponential_distribution& x,
+                           const exponential_distribution& y);
+    friend bool operator!=(const exponential_distribution& x,
+                           const exponential_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const exponential_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               exponential_distribution& x);
+};
+
+template<class RealType = double>
+class gamma_distribution
+{
+public:
+    // types
+    typedef RealType result_type;
+
+    class param_type
+    {
+    public:
+        typedef gamma_distribution distribution_type;
+
+        explicit param_type(result_type alpha = 1, result_type beta = 1);
+
+        result_type alpha() const;
+        result_type beta() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructors and reset functions
+    explicit gamma_distribution(result_type alpha = 1, result_type beta = 1);
+    explicit gamma_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    result_type alpha() const;
+    result_type beta() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const gamma_distribution& x,
+                           const gamma_distribution& y);
+    friend bool operator!=(const gamma_distribution& x,
+                           const gamma_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const gamma_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               gamma_distribution& x);
+};
+
+template<class RealType = double>
+class weibull_distribution
+{
+public:
+    // types
+    typedef RealType result_type;
+
+    class param_type
+    {
+    public:
+        typedef weibull_distribution distribution_type;
+
+        explicit param_type(result_type alpha = 1, result_type beta = 1);
+
+        result_type a() const;
+        result_type b() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructor and reset functions
+    explicit weibull_distribution(result_type a = 1, result_type b = 1);
+    explicit weibull_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    result_type a() const;
+    result_type b() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const weibull_distribution& x,
+                           const weibull_distribution& y);
+    friend bool operator!=(const weibull_distribution& x,
+                           const weibull_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const weibull_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               weibull_distribution& x);
+};
+
+template<class RealType = double>
+class extreme_value_distribution
+{
+public:
+    // types
+    typedef RealType result_type;
+
+    class param_type
+    {
+    public:
+        typedef extreme_value_distribution distribution_type;
+
+        explicit param_type(result_type a = 0, result_type b = 1);
+
+        result_type a() const;
+        result_type b() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructor and reset functions
+    explicit extreme_value_distribution(result_type a = 0, result_type b = 1);
+    explicit extreme_value_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    result_type a() const;
+    result_type b() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const extreme_value_distribution& x,
+                           const extreme_value_distribution& y);
+    friend bool operator!=(const extreme_value_distribution& x,
+                           const extreme_value_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const extreme_value_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               extreme_value_distribution& x);
+};
+
+template<class RealType = double>
+class normal_distribution
+{
+public:
+    // types
+    typedef RealType result_type;
+
+    class param_type
+    {
+    public:
+        typedef normal_distribution distribution_type;
+
+        explicit param_type(result_type mean = 0, result_type stddev = 1);
+
+        result_type mean() const;
+        result_type stddev() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructors and reset functions
+    explicit normal_distribution(result_type mean = 0, result_type stddev = 1);
+    explicit normal_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    result_type mean() const;
+    result_type stddev() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const normal_distribution& x,
+                           const normal_distribution& y);
+    friend bool operator!=(const normal_distribution& x,
+                           const normal_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const normal_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               normal_distribution& x);
+};
+
+template<class RealType = double>
+class lognormal_distribution
+{
+public:
+    // types
+    typedef RealType result_type;
+
+    class param_type
+    {
+    public:
+        typedef lognormal_distribution distribution_type;
+
+        explicit param_type(result_type m = 0, result_type s = 1);
+
+        result_type m() const;
+        result_type s() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructor and reset functions
+    explicit lognormal_distribution(result_type m = 0, result_type s = 1);
+    explicit lognormal_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    result_type m() const;
+    result_type s() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const lognormal_distribution& x,
+                           const lognormal_distribution& y);
+    friend bool operator!=(const lognormal_distribution& x,
+                           const lognormal_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const lognormal_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               lognormal_distribution& x);
+};
+
+template<class RealType = double>
+class chi_squared_distribution
+{
+public:
+    // types
+    typedef RealType result_type;
+
+    class param_type
+    {
+    public:
+        typedef chi_squared_distribution distribution_type;
+
+        explicit param_type(result_type n = 1);
+
+        result_type n() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructor and reset functions
+    explicit chi_squared_distribution(result_type n = 1);
+    explicit chi_squared_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    result_type n() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const chi_squared_distribution& x,
+                           const chi_squared_distribution& y);
+    friend bool operator!=(const chi_squared_distribution& x,
+                           const chi_squared_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const chi_squared_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               chi_squared_distribution& x);
+};
+
+template<class RealType = double>
+class cauchy_distribution
+{
+public:
+    // types
+    typedef RealType result_type;
+
+    class param_type
+    {
+    public:
+        typedef cauchy_distribution distribution_type;
+
+        explicit param_type(result_type a = 0, result_type b = 1);
+
+        result_type a() const;
+        result_type b() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructor and reset functions
+    explicit cauchy_distribution(result_type a = 0, result_type b = 1);
+    explicit cauchy_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    result_type a() const;
+    result_type b() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const cauchy_distribution& x,
+                           const cauchy_distribution& y);
+    friend bool operator!=(const cauchy_distribution& x,
+                           const cauchy_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const cauchy_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               cauchy_distribution& x);
+};
+
+template<class RealType = double>
+class fisher_f_distribution
+{
+public:
+    // types
+    typedef RealType result_type;
+
+    class param_type
+    {
+    public:
+        typedef fisher_f_distribution distribution_type;
+
+        explicit param_type(result_type m = 1, result_type n = 1);
+
+        result_type m() const;
+        result_type n() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructor and reset functions
+    explicit fisher_f_distribution(result_type m = 1, result_type n = 1);
+    explicit fisher_f_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    result_type m() const;
+    result_type n() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const fisher_f_distribution& x,
+                           const fisher_f_distribution& y);
+    friend bool operator!=(const fisher_f_distribution& x,
+                           const fisher_f_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const fisher_f_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               fisher_f_distribution& x);
+};
+
+template<class RealType = double>
+class student_t_distribution
+{
+public:
+    // types
+    typedef RealType result_type;
+
+    class param_type
+    {
+    public:
+        typedef student_t_distribution distribution_type;
+
+        explicit param_type(result_type n = 1);
+
+        result_type n() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructor and reset functions
+    explicit student_t_distribution(result_type n = 1);
+    explicit student_t_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    result_type n() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const student_t_distribution& x,
+                           const student_t_distribution& y);
+    friend bool operator!=(const student_t_distribution& x,
+                           const student_t_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const student_t_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               student_t_distribution& x);
+};
+
+template<class IntType = int>
+class discrete_distribution
+{
+public:
+    // types
+    typedef IntType result_type;
+
+    class param_type
+    {
+    public:
+        typedef discrete_distribution distribution_type;
+
+        param_type();
+        template<class InputIterator>
+            param_type(InputIterator firstW, InputIterator lastW);
+        param_type(initializer_list<double> wl);
+        template<class UnaryOperation>
+            param_type(size_t nw, double xmin, double xmax, UnaryOperation fw);
+
+        vector<double> probabilities() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructor and reset functions
+    discrete_distribution();
+    template<class InputIterator>
+        discrete_distribution(InputIterator firstW, InputIterator lastW);
+    discrete_distribution(initializer_list<double> wl);
+    template<class UnaryOperation>
+        discrete_distribution(size_t nw, double xmin, double xmax,
+                              UnaryOperation fw);
+    explicit discrete_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    vector<double> probabilities() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const discrete_distribution& x,
+                           const discrete_distribution& y);
+    friend bool operator!=(const discrete_distribution& x,
+                           const discrete_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const discrete_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               discrete_distribution& x);
+};
+
+template<class RealType = double>
+class piecewise_constant_distribution
+{
+    // types
+    typedef RealType result_type;
+
+    class param_type
+    {
+    public:
+        typedef piecewise_constant_distribution distribution_type;
+
+        param_type();
+        template<class InputIteratorB, class InputIteratorW>
+            param_type(InputIteratorB firstB, InputIteratorB lastB,
+                       InputIteratorW firstW);
+        template<class UnaryOperation>
+            param_type(initializer_list<result_type> bl, UnaryOperation fw);
+        template<class UnaryOperation>
+            param_type(size_t nw, result_type xmin, result_type xmax,
+                       UnaryOperation fw);
+
+        vector<result_type> intervals() const;
+        vector<result_type> densities() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructor and reset functions
+    piecewise_constant_distribution();
+    template<class InputIteratorB, class InputIteratorW>
+        piecewise_constant_distribution(InputIteratorB firstB,
+                                        InputIteratorB lastB,
+                                        InputIteratorW firstW);
+    template<class UnaryOperation>
+        piecewise_constant_distribution(initializer_list<result_type> bl,
+                                        UnaryOperation fw);
+    template<class UnaryOperation>
+        piecewise_constant_distribution(size_t nw, result_type xmin,
+                                        result_type xmax, UnaryOperation fw);
+    explicit piecewise_constant_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    vector<result_type> intervals() const;
+    vector<result_type> densities() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const piecewise_constant_distribution& x,
+                           const piecewise_constant_distribution& y);
+    friend bool operator!=(const piecewise_constant_distribution& x,
+                           const piecewise_constant_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const piecewise_constant_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               piecewise_constant_distribution& x);
+};
+
+template<class RealType = double>
+class piecewise_linear_distribution
+{
+    // types
+    typedef RealType result_type;
+
+    class param_type
+    {
+    public:
+        typedef piecewise_linear_distribution distribution_type;
+
+        param_type();
+        template<class InputIteratorB, class InputIteratorW>
+            param_type(InputIteratorB firstB, InputIteratorB lastB,
+                       InputIteratorW firstW);
+        template<class UnaryOperation>
+            param_type(initializer_list<result_type> bl, UnaryOperation fw);
+        template<class UnaryOperation>
+            param_type(size_t nw, result_type xmin, result_type xmax,
+                       UnaryOperation fw);
+
+        vector<result_type> intervals() const;
+        vector<result_type> densities() const;
+
+        friend bool operator==(const param_type& x, const param_type& y);
+        friend bool operator!=(const param_type& x, const param_type& y);
+    };
+
+    // constructor and reset functions
+    piecewise_linear_distribution();
+    template<class InputIteratorB, class InputIteratorW>
+        piecewise_linear_distribution(InputIteratorB firstB,
+                                      InputIteratorB lastB,
+                                      InputIteratorW firstW);
+
+    template<class UnaryOperation>
+        piecewise_linear_distribution(initializer_list<result_type> bl,
+                                      UnaryOperation fw);
+
+    template<class UnaryOperation>
+        piecewise_linear_distribution(size_t nw, result_type xmin,
+                                      result_type xmax, UnaryOperation fw);
+
+    explicit piecewise_linear_distribution(const param_type& parm);
+    void reset();
+
+    // generating functions
+    template<class URNG> result_type operator()(URNG& g);
+    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
+
+    // property functions
+    vector<result_type> intervals() const;
+    vector<result_type> densities() const;
+
+    param_type param() const;
+    void param(const param_type& parm);
+
+    result_type min() const;
+    result_type max() const;
+
+    friend bool operator==(const piecewise_linear_distribution& x,
+                           const piecewise_linear_distribution& y);
+    friend bool operator!=(const piecewise_linear_distribution& x,
+                           const piecewise_linear_distribution& y);
+
+    template <class charT, class traits>
+    friend
+    basic_ostream<charT, traits>&
+    operator<<(basic_ostream<charT, traits>& os,
+               const piecewise_linear_distribution& x);
+
+    template <class charT, class traits>
+    friend
+    basic_istream<charT, traits>&
+    operator>>(basic_istream<charT, traits>& is,
+               piecewise_linear_distribution& x);
+};
+
+} // std
+*/
+
+#include <__config>
+#include <cstddef>
+#include <cstdint>
+#include <cmath>
+#include <type_traits>
+#include <initializer_list>
+#include <limits>
+#include <algorithm>
+#include <numeric>
+#include <vector>
+#include <string>
+#include <istream>
+#include <ostream>
+
+#include <__undef_min_max>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+// __is_seed_sequence
+
+template <class _Sseq, class _Engine>
+struct __is_seed_sequence
+{
+    static _LIBCPP_CONSTEXPR const bool value =
+              !is_convertible<_Sseq, typename _Engine::result_type>::value &&
+              !is_same<typename remove_cv<_Sseq>::type, _Engine>::value;
+};
+
+// linear_congruential_engine
+
+template <unsigned long long __a, unsigned long long __c,
+          unsigned long long __m, unsigned long long _Mp,
+          bool _MightOverflow = (__a != 0 && __m != 0 && __m-1 > (_Mp-__c)/__a)>
+struct __lce_ta;
+
+// 64
+
+template <unsigned long long __a, unsigned long long __c, unsigned long long __m>
+struct __lce_ta<__a, __c, __m, (unsigned long long)(~0), true>
+{
+    typedef unsigned long long result_type;
+    _LIBCPP_INLINE_VISIBILITY
+    static result_type next(result_type __x)
+    {
+        // Schrage's algorithm
+        const result_type __q = __m / __a;
+        const result_type __r = __m % __a;
+        const result_type __t0 = __a * (__x % __q);
+        const result_type __t1 = __r * (__x / __q);
+        __x = __t0 + (__t0 < __t1) * __m - __t1;
+        __x += __c - (__x >= __m - __c) * __m;
+        return __x;
+    }
+};
+
+template <unsigned long long __a, unsigned long long __m>
+struct __lce_ta<__a, 0, __m, (unsigned long long)(~0), true>
+{
+    typedef unsigned long long result_type;
+    _LIBCPP_INLINE_VISIBILITY
+    static result_type next(result_type __x)
+    {
+        // Schrage's algorithm
+        const result_type __q = __m / __a;
+        const result_type __r = __m % __a;
+        const result_type __t0 = __a * (__x % __q);
+        const result_type __t1 = __r * (__x / __q);
+        __x = __t0 + (__t0 < __t1) * __m - __t1;
+        return __x;
+    }
+};
+
+template <unsigned long long __a, unsigned long long __c, unsigned long long __m>
+struct __lce_ta<__a, __c, __m, (unsigned long long)(~0), false>
+{
+    typedef unsigned long long result_type;
+    _LIBCPP_INLINE_VISIBILITY
+    static result_type next(result_type __x)
+    {
+        return (__a * __x + __c) % __m;
+    }
+};
+
+template <unsigned long long __a, unsigned long long __c>
+struct __lce_ta<__a, __c, 0, (unsigned long long)(~0), false>
+{
+    typedef unsigned long long result_type;
+    _LIBCPP_INLINE_VISIBILITY
+    static result_type next(result_type __x)
+    {
+        return __a * __x + __c;
+    }
+};
+
+// 32
+
+template <unsigned long long _Ap, unsigned long long _Cp, unsigned long long _Mp>
+struct __lce_ta<_Ap, _Cp, _Mp, unsigned(~0), true>
+{
+    typedef unsigned result_type;
+    _LIBCPP_INLINE_VISIBILITY
+    static result_type next(result_type __x)
+    {
+        const result_type __a = static_cast<result_type>(_Ap);
+        const result_type __c = static_cast<result_type>(_Cp);
+        const result_type __m = static_cast<result_type>(_Mp);
+        // Schrage's algorithm
+        const result_type __q = __m / __a;
+        const result_type __r = __m % __a;
+        const result_type __t0 = __a * (__x % __q);
+        const result_type __t1 = __r * (__x / __q);
+        __x = __t0 + (__t0 < __t1) * __m - __t1;
+        __x += __c - (__x >= __m - __c) * __m;
+        return __x;
+    }
+};
+
+template <unsigned long long _Ap, unsigned long long _Mp>
+struct __lce_ta<_Ap, 0, _Mp, unsigned(~0), true>
+{
+    typedef unsigned result_type;
+    _LIBCPP_INLINE_VISIBILITY
+    static result_type next(result_type __x)
+    {
+        const result_type __a = static_cast<result_type>(_Ap);
+        const result_type __m = static_cast<result_type>(_Mp);
+        // Schrage's algorithm
+        const result_type __q = __m / __a;
+        const result_type __r = __m % __a;
+        const result_type __t0 = __a * (__x % __q);
+        const result_type __t1 = __r * (__x / __q);
+        __x = __t0 + (__t0 < __t1) * __m - __t1;
+        return __x;
+    }
+};
+
+template <unsigned long long _Ap, unsigned long long _Cp, unsigned long long _Mp>
+struct __lce_ta<_Ap, _Cp, _Mp, unsigned(~0), false>
+{
+    typedef unsigned result_type;
+    _LIBCPP_INLINE_VISIBILITY
+    static result_type next(result_type __x)
+    {
+        const result_type __a = static_cast<result_type>(_Ap);
+        const result_type __c = static_cast<result_type>(_Cp);
+        const result_type __m = static_cast<result_type>(_Mp);
+        return (__a * __x + __c) % __m;
+    }
+};
+
+template <unsigned long long _Ap, unsigned long long _Cp>
+struct __lce_ta<_Ap, _Cp, 0, unsigned(~0), false>
+{
+    typedef unsigned result_type;
+    _LIBCPP_INLINE_VISIBILITY
+    static result_type next(result_type __x)
+    {
+        const result_type __a = static_cast<result_type>(_Ap);
+        const result_type __c = static_cast<result_type>(_Cp);
+        return __a * __x + __c;
+    }
+};
+
+// 16
+
+template <unsigned long long __a, unsigned long long __c, unsigned long long __m, bool __b>
+struct __lce_ta<__a, __c, __m, (unsigned short)(~0), __b>
+{
+    typedef unsigned short result_type;
+    _LIBCPP_INLINE_VISIBILITY
+    static result_type next(result_type __x)
+    {
+        return static_cast<result_type>(__lce_ta<__a, __c, __m, unsigned(~0)>::next(__x));
+    }
+};
+
+template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
+class _LIBCPP_TYPE_VIS_ONLY linear_congruential_engine;
+
+template <class _CharT, class _Traits,
+          class _Up, _Up _Ap, _Up _Cp, _Up _Np>
+_LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os,
+           const linear_congruential_engine<_Up, _Ap, _Cp, _Np>&);
+
+template <class _CharT, class _Traits,
+          class _Up, _Up _Ap, _Up _Cp, _Up _Np>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is,
+           linear_congruential_engine<_Up, _Ap, _Cp, _Np>& __x);
+
+template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
+class _LIBCPP_TYPE_VIS_ONLY linear_congruential_engine
+{
+public:
+    // types
+    typedef _UIntType result_type;
+
+private:
+    result_type __x_;
+
+    static _LIBCPP_CONSTEXPR const result_type _Mp = result_type(~0);
+
+    static_assert(__m == 0 || __a < __m, "linear_congruential_engine invalid parameters");
+    static_assert(__m == 0 || __c < __m, "linear_congruential_engine invalid parameters");
+public:
+    static _LIBCPP_CONSTEXPR const result_type _Min = __c == 0u ? 1u: 0u;
+    static _LIBCPP_CONSTEXPR const result_type _Max = __m - 1u;
+    static_assert(_Min < _Max,           "linear_congruential_engine invalid parameters");
+
+    // engine characteristics
+    static _LIBCPP_CONSTEXPR const result_type multiplier = __a;
+    static _LIBCPP_CONSTEXPR const result_type increment = __c;
+    static _LIBCPP_CONSTEXPR const result_type modulus = __m;
+    _LIBCPP_INLINE_VISIBILITY
+    static _LIBCPP_CONSTEXPR result_type min() {return _Min;}
+    _LIBCPP_INLINE_VISIBILITY
+    static _LIBCPP_CONSTEXPR result_type max() {return _Max;}
+    static _LIBCPP_CONSTEXPR const result_type default_seed = 1u;
+
+    // constructors and seeding functions
+    _LIBCPP_INLINE_VISIBILITY
+    explicit linear_congruential_engine(result_type __s = default_seed)
+        {seed(__s);}
+    template<class _Sseq>
+        _LIBCPP_INLINE_VISIBILITY
+        explicit linear_congruential_engine(_Sseq& __q,
+        typename enable_if<__is_seed_sequence<_Sseq, linear_congruential_engine>::value>::type* = 0)
+        {seed(__q);}
+    _LIBCPP_INLINE_VISIBILITY
+    void seed(result_type __s = default_seed)
+        {seed(integral_constant<bool, __m == 0>(),
+              integral_constant<bool, __c == 0>(), __s);}
+    template<class _Sseq>
+        _LIBCPP_INLINE_VISIBILITY
+        typename enable_if
+        <
+            __is_seed_sequence<_Sseq, linear_congruential_engine>::value,
+            void
+        >::type
+        seed(_Sseq& __q)
+            {__seed(__q, integral_constant<unsigned,
+                1 + (__m == 0 ? (sizeof(result_type) * __CHAR_BIT__ - 1)/32
+                             :  (__m > 0x100000000ull))>());}
+
+    // generating functions
+    _LIBCPP_INLINE_VISIBILITY
+    result_type operator()()
+        {return __x_ = static_cast<result_type>(__lce_ta<__a, __c, __m, _Mp>::next(__x_));}
+    _LIBCPP_INLINE_VISIBILITY
+    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
+
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator==(const linear_congruential_engine& __x,
+                    const linear_congruential_engine& __y)
+        {return __x.__x_ == __y.__x_;}
+    friend _LIBCPP_INLINE_VISIBILITY
+    bool operator!=(const linear_congruential_engine& __x,
+                    const linear_congruential_engine& __y)
+        {return !(__x == __y);}
+
+private:
+
+    _LIBCPP_INLINE_VISIBILITY
+    void seed(true_type, true_type, result_type __s) {__x_ = __s == 0 ? 1 : __s;}
+    _LIBCPP_INLINE_VISIBILITY
+    void seed(true_type, false_type, result_type __s) {__x_ = __s;}
+    _LIBCPP_INLINE_VISIBILITY
+    void seed(false_type, true_type, result_type __s) {__x_ = __s % __m == 0 ?
+                                                                 1 : __s % __m;}
+    _LIBCPP_INLINE_VISIBILITY
+    void seed(false_type, false_type, result_type __s) {__x_ = __s % __m;}
+
+    template<class _Sseq>
+        void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
+    template<class _Sseq>
+        void __seed(_Sseq& __q, integral_constant<unsigned, 2>);
+
+    template <class _CharT, class _Traits,
+              class _Up, _Up _Ap, _Up _Cp, _Up _Np>
+    friend
+    basic_ostream<_CharT, _Traits>&
+    operator<<(basic_ostream<_CharT, _Traits>& __os,
+               const linear_congruential_engine<_Up, _Ap, _Cp, _Np>&);
+
+    template <class _CharT, class _Traits,
+              class _Up, _Up _Ap, _Up _Cp, _Up _Np>
+    friend
+    basic_istream<_CharT, _Traits>&
+    operator>>(basic_istream<_CharT, _Traits>& __is,
+               linear_congruential_engine<_Up, _Ap, _Cp, _Np>& __x);
+};
+
+template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
+    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
+    linear_congruential_engine<_UIntType, __a, __c, __m>::multiplier;
+
+template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
+    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
+    linear_congruential_engine<_UIntType, __a, __c, __m>::increment;
+
+template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
+    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
+    linear_congruential_engine<_UIntType, __a, __c, __m>::modulus;
+
+template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
+    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
+    linear_congruential_engine<_UIntType, __a, __c, __m>::default_seed;
+
+template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
+template<class _Sseq>
+void
+linear_congruential_engine<_UIntType, __a, __c, __m>::__seed(_Sseq& __q,
+                                                 integral_constant<unsigned, 1>)
+{
+    const unsigned __k = 1;
+    uint32_t __ar[__k+3];
+    __q.generate(__ar, __ar + __k + 3);
+    result_type __s = static_cast<result_type>(__ar[3] % __m);
+    __x_ = __c == 0 && __s == 0 ? result_type(1) : __s;
+}
+
+template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
+template<class _Sseq>
+void
+linear_congruential_engine<_UIntType, __a, __c, __m>::__seed(_Sseq& __q,
+                                                 integral_constant<unsigned, 2>)
+{
+    const unsigned __k = 2;
+    uint32_t __ar[__k+3];
+    __q.generate(__ar, __ar + __k + 3);
+    result_type __s = static_cast<result_type>((__ar[3] +
+                                              ((uint64_t)__ar[4] << 32)) % __m);
+    __x_ = __c == 0 && __s == 0 ? result_type(1) : __s;
+}
+
+template <class _CharT, class _Traits,
+          class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
+inline _LIBCPP_INLINE_VISIBILITY
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os,
+           const linear_congruential_engine<_UIntType, __a, __c, __m>& __x)
+{
+    __save_flags<_CharT, _Traits> __lx(__os);
+    __os.flags(ios_base::dec | ios_base::left);
+    __os.fill(__os.widen(' '));
+    return __os << __x.__x_;
+}
+
+template <class _CharT, class _Traits,
+          class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is,
+           linear_congruential_engine<_UIntType, __a, __c, __m>& __x)
+{
+    __save_flags<_CharT, _Traits> __lx(__is);
+    __is.flags(ios_base::dec | ios_base::skipws);
+    _UIntType __t;
+    __is >> __t;
+    if (!__is.fail())
+        __x.__x_ = __t;
+    return __is;
+}
+
+typedef linear_congruential_engine<uint_fast32_t, 16807, 0, 2147483647>
+                                                                   minstd_rand0;
+typedef linear_congruential_engine<uint_fast32_t, 48271, 0, 2147483647>
+                                                                    minstd_rand;
+typedef minstd_rand                                       default_random_engine;
+// mersenne_twister_engine
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+class _LIBCPP_TYPE_VIS_ONLY mersenne_twister_engine;
+
+template <class _UI, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
+          _UI _Ap, size_t _Up, _UI _Dp, size_t _Sp,
+          _UI _Bp, size_t _Tp, _UI _Cp, size_t _Lp, _UI _Fp>
+bool
+operator==(const mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
+           const mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
+
+template <class _UI, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
+          _UI _Ap, size_t _Up, _UI _Dp, size_t _Sp,
+          _UI _Bp, size_t _Tp, _UI _Cp, size_t _Lp, _UI _Fp>
+_LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
+           const mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
+
+template <class _CharT, class _Traits,
+          class _UI, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
+          _UI _Ap, size_t _Up, _UI _Dp, size_t _Sp,
+          _UI _Bp, size_t _Tp, _UI _Cp, size_t _Lp, _UI _Fp>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os,
+           const mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
+
+template <class _CharT, class _Traits,
+          class _UI, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
+          _UI _Ap, size_t _Up, _UI _Dp, size_t _Sp,
+          _UI _Bp, size_t _Tp, _UI _Cp, size_t _Lp, _UI _Fp>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is,
+           mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                   _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+class _LIBCPP_TYPE_VIS_ONLY mersenne_twister_engine
+{
+public:
+    // types
+    typedef _UIntType result_type;
+
+private:
+    result_type __x_[__n];
+    size_t      __i_;
+
+    static_assert(  0 <  __m, "mersenne_twister_engine invalid parameters");
+    static_assert(__m <= __n, "mersenne_twister_engine invalid parameters");
+    static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
+    static_assert(__w <= _Dt, "mersenne_twister_engine invalid parameters");
+    static_assert(  2 <= __w, "mersenne_twister_engine invalid parameters");
+    static_assert(__r <= __w, "mersenne_twister_engine invalid parameters");
+    static_assert(__u <= __w, "mersenne_twister_engine invalid parameters");
+    static_assert(__s <= __w, "mersenne_twister_engine invalid parameters");
+    static_assert(__t <= __w, "mersenne_twister_engine invalid parameters");
+    static_assert(__l <= __w, "mersenne_twister_engine invalid parameters");
+public:
+    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
+    static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
+                                                      (result_type(1) << __w) - result_type(1);
+    static_assert(_Min < _Max, "mersenne_twister_engine invalid parameters");
+    static_assert(__a <= _Max, "mersenne_twister_engine invalid parameters");
+    static_assert(__b <= _Max, "mersenne_twister_engine invalid parameters");
+    static_assert(__c <= _Max, "mersenne_twister_engine invalid parameters");
+    static_assert(__d <= _Max, "mersenne_twister_engine invalid parameters");
+    static_assert(__f <= _Max, "mersenne_twister_engine invalid parameters");
+
+    // engine characteristics
+    static _LIBCPP_CONSTEXPR const size_t word_size = __w;
+    static _LIBCPP_CONSTEXPR const size_t state_size = __n;
+    static _LIBCPP_CONSTEXPR const size_t shift_size = __m;
+    static _LIBCPP_CONSTEXPR const size_t mask_bits = __r;
+    static _LIBCPP_CONSTEXPR const result_type xor_mask = __a;
+    static _LIBCPP_CONSTEXPR const size_t tempering_u = __u;
+    static _LIBCPP_CONSTEXPR const result_type tempering_d = __d;
+    static _LIBCPP_CONSTEXPR const size_t tempering_s = __s;
+    static _LIBCPP_CONSTEXPR const result_type tempering_b = __b;
+    static _LIBCPP_CONSTEXPR const size_t tempering_t = __t;
+    static _LIBCPP_CONSTEXPR const result_type tempering_c = __c;
+    static _LIBCPP_CONSTEXPR const size_t tempering_l = __l;
+    static _LIBCPP_CONSTEXPR const result_type initialization_multiplier = __f;
+    _LIBCPP_INLINE_VISIBILITY
+    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
+    _LIBCPP_INLINE_VISIBILITY
+    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
+    static _LIBCPP_CONSTEXPR const result_type default_seed = 5489u;
+
+    // constructors and seeding functions
+    _LIBCPP_INLINE_VISIBILITY
+    explicit mersenne_twister_engine(result_type __sd = default_seed)
+        {seed(__sd);}
+    template<class _Sseq>
+        _LIBCPP_INLINE_VISIBILITY
+        explicit mersenne_twister_engine(_Sseq& __q,
+        typename enable_if<__is_seed_sequence<_Sseq, mersenne_twister_engine>::value>::type* = 0)
+        {seed(__q);}
+    void seed(result_type __sd = default_seed);
+    template<class _Sseq>
+        _LIBCPP_INLINE_VISIBILITY
+        typename enable_if
+        <
+            __is_seed_sequence<_Sseq, mersenne_twister_engine>::value,
+            void
+        >::type
+        seed(_Sseq& __q)
+            {__seed(__q, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
+
+    // generating functions
+    result_type operator()();
+    _LIBCPP_INLINE_VISIBILITY
+    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
+
+    template <class _UI, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
+              _UI _Ap, size_t _Up, _UI _Dp, size_t _Sp,
+              _UI _Bp, size_t _Tp, _UI _Cp, size_t _Lp, _UI _Fp>
+    friend
+    bool
+    operator==(const mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
+               const mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
+
+    template <class _UI, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
+              _UI _Ap, size_t _Up, _UI _Dp, size_t _Sp,
+              _UI _Bp, size_t _Tp, _UI _Cp, size_t _Lp, _UI _Fp>
+    friend
+    bool
+    operator!=(const mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
+               const mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
+
+    template <class _CharT, class _Traits,
+              class _UI, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
+              _UI _Ap, size_t _Up, _UI _Dp, size_t _Sp,
+              _UI _Bp, size_t _Tp, _UI _Cp, size_t _Lp, _UI _Fp>
+    friend
+    basic_ostream<_CharT, _Traits>&
+    operator<<(basic_ostream<_CharT, _Traits>& __os,
+               const mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
+
+    template <class _CharT, class _Traits,
+              class _UI, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
+              _UI _Ap, size_t _Up, _UI _Dp, size_t _Sp,
+              _UI _Bp, size_t _Tp, _UI _Cp, size_t _Lp, _UI _Fp>
+    friend
+    basic_istream<_CharT, _Traits>&
+    operator>>(basic_istream<_CharT, _Traits>& __is,
+               mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                       _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
+private:
+
+    template<class _Sseq>
+        void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
+    template<class _Sseq>
+        void __seed(_Sseq& __q, integral_constant<unsigned, 2>);
+
+    template <size_t __count>
+        _LIBCPP_INLINE_VISIBILITY
+        static
+        typename enable_if
+        <
+            __count < __w,
+            result_type
+        >::type
+        __lshift(result_type __x) {return (__x << __count) & _Max;}
+
+    template <size_t __count>
+        _LIBCPP_INLINE_VISIBILITY
+        static
+        typename enable_if
+        <
+            (__count >= __w),
+            result_type
+        >::type
+        __lshift(result_type) {return result_type(0);}
+
+    template <size_t __count>
+        _LIBCPP_INLINE_VISIBILITY
+        static
+        typename enable_if
+        <
+            __count < _Dt,
+            result_type
+        >::type
+        __rshift(result_type __x) {return __x >> __count;}
+
+    template <size_t __count>
+        _LIBCPP_INLINE_VISIBILITY
+        static
+        typename enable_if
+        <
+            (__count >= _Dt),
+            result_type
+        >::type
+        __rshift(result_type) {return result_type(0);}
+};
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+    _LIBCPP_CONSTEXPR const size_t
+    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::word_size;
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+    _LIBCPP_CONSTEXPR const size_t 
+    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::state_size;
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+    _LIBCPP_CONSTEXPR const size_t 
+    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::shift_size;
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+    _LIBCPP_CONSTEXPR const size_t 
+    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::mask_bits;
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
+    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::xor_mask;
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+    _LIBCPP_CONSTEXPR const size_t 
+    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_u;
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
+    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_d;
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+    _LIBCPP_CONSTEXPR const size_t 
+    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_s;
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
+    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_b;
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+    _LIBCPP_CONSTEXPR const size_t 
+    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_t;
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
+    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_c;
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+    _LIBCPP_CONSTEXPR const size_t 
+    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_l;
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
+    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::initialization_multiplier;
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
+    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::default_seed;
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+void
+mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
+    __t, __c, __l, __f>::seed(result_type __sd)
+{   // __w >= 2
+    __x_[0] = __sd & _Max;
+    for (size_t __i = 1; __i < __n; ++__i)
+        __x_[__i] = (__f * (__x_[__i-1] ^ __rshift<__w - 2>(__x_[__i-1])) + __i) & _Max;
+    __i_ = 0;
+}
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+template<class _Sseq>
+void
+mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
+    __t, __c, __l, __f>::__seed(_Sseq& __q, integral_constant<unsigned, 1>)
+{
+    const unsigned __k = 1;
+    uint32_t __ar[__n * __k];
+    __q.generate(__ar, __ar + __n * __k);
+    for (size_t __i = 0; __i < __n; ++__i)
+        __x_[__i] = static_cast<result_type>(__ar[__i] & _Max);
+    const result_type __mask = __r == _Dt ? result_type(~0) :
+                                       (result_type(1) << __r) - result_type(1);
+    __i_ = 0;
+    if ((__x_[0] & ~__mask) == 0)
+    {
+        for (size_t __i = 1; __i < __n; ++__i)
+            if (__x_[__i] != 0)
+                return;
+        __x_[0] = _Max;
+    }
+}
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+template<class _Sseq>
+void
+mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
+    __t, __c, __l, __f>::__seed(_Sseq& __q, integral_constant<unsigned, 2>)
+{
+    const unsigned __k = 2;
+    uint32_t __ar[__n * __k];
+    __q.generate(__ar, __ar + __n * __k);
+    for (size_t __i = 0; __i < __n; ++__i)
+        __x_[__i] = static_cast<result_type>(
+            (__ar[2 * __i] + ((uint64_t)__ar[2 * __i + 1] << 32)) & _Max);
+    const result_type __mask = __r == _Dt ? result_type(~0) :
+                                       (result_type(1) << __r) - result_type(1);
+    __i_ = 0;
+    if ((__x_[0] & ~__mask) == 0)
+    {
+        for (size_t __i = 1; __i < __n; ++__i)
+            if (__x_[__i] != 0)
+                return;
+        __x_[0] = _Max;
+    }
+}
+
+template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
+          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
+          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
+_UIntType
+mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
+    __t, __c, __l, __f>::operator()()
+{
+    const size_t __j = (__i_ + 1) % __n;
+    const result_type __mask = __r == _Dt ? result_type(~0) :
+                                       (result_type(1) << __r) - result_type(1);
+    const result_type _Yp = (__x_[__i_] & ~__mask) | (__x_[__j] & __mask);
+    const size_t __k = (__i_ + __m) % __n;
+    __x_[__i_] = __x_[__k] ^ __rshift<1>(_Yp) ^ (__a * (_Yp & 1));
+    result_type __z = __x_[__i_] ^ (__rshift<__u>(__x_[__i_]) & __d);
+    __i_ = __j;
+    __z ^= __lshift<__s>(__z) & __b;
+    __z ^= __lshift<__t>(__z) & __c;
+    return __z ^ __rshift<__l>(__z);
+}
+
+template <class _UI, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
+          _UI _Ap, size_t _Up, _UI _Dp, size_t _Sp,
+          _UI _Bp, size_t _Tp, _UI _Cp, size_t _Lp, _UI _Fp>
+bool
+operator==(const mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
+           const mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y)
+{
+    if (__x.__i_ == __y.__i_)
+        return _VSTD::equal(__x.__x_, __x.__x_ + _Np, __y.__x_);
+    if (__x.__i_ == 0 || __y.__i_ == 0)
+    {
+        size_t __j = _VSTD::min(_Np - __x.__i_, _Np - __y.__i_);
+        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + __x.__i_ + __j,
+                         __y.__x_ + __y.__i_))
+            return false;
+        if (__x.__i_ == 0)
+            return _VSTD::equal(__x.__x_ + __j, __x.__x_ + _Np, __y.__x_);
+        return _VSTD::equal(__x.__x_, __x.__x_ + (_Np - __j), __y.__x_ + __j);
+    }
+    if (__x.__i_ < __y.__i_)
+    {
+        size_t __j = _Np - __y.__i_;
+        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + (__x.__i_ + __j),
+                         __y.__x_ + __y.__i_))
+            return false;
+        if (!_VSTD::equal(__x.__x_ + (__x.__i_ + __j), __x.__x_ + _Np,
+                         __y.__x_))
+            return false;
+        return _VSTD::equal(__x.__x_, __x.__x_ + __x.__i_,
+                           __y.__x_ + (_Np - (__x.__i_ + __j)));
+    }
+    size_t __j = _Np - __x.__i_;
+    if (!_VSTD::equal(__y.__x_ + __y.__i_, __y.__x_ + (__y.__i_ + __j),
+                     __x.__x_ + __x.__i_))
+        return false;
+    if (!_VSTD::equal(__y.__x_ + (__y.__i_ + __j), __y.__x_ + _Np,
+                     __x.__x_))
+        return false;
+    return _VSTD::equal(__y.__x_, __y.__x_ + __y.__i_,
+                       __x.__x_ + (_Np - (__y.__i_ + __j)));
+}
+
+template <class _UI, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
+          _UI _Ap, size_t _Up, _UI _Dp, size_t _Sp,
+          _UI _Bp, size_t _Tp, _UI _Cp, size_t _Lp, _UI _Fp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
+           const mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y)
+{
+    return !(__x == __y);
+}
+
+template <class _CharT, class _Traits,
+          class _UI, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
+          _UI _Ap, size_t _Up, _UI _Dp, size_t _Sp,
+          _UI _Bp, size_t _Tp, _UI _Cp, size_t _Lp, _UI _Fp>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os,
+           const mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x)
+{
+    __save_flags<_CharT, _Traits> __lx(__os);
+    __os.flags(ios_base::dec | ios_base::left);
+    _CharT __sp = __os.widen(' ');
+    __os.fill(__sp);
+    __os << __x.__x_[__x.__i_];
+    for (size_t __j = __x.__i_ + 1; __j < _Np; ++__j)
+        __os << __sp << __x.__x_[__j];
+    for (size_t __j = 0; __j < __x.__i_; ++__j)
+        __os << __sp << __x.__x_[__j];
+    return __os;
+}
+
+template <class _CharT, class _Traits,
+          class _UI, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
+          _UI _Ap, size_t _Up, _UI _Dp, size_t _Sp,
+          _UI _Bp, size_t _Tp, _UI _Cp, size_t _Lp, _UI _Fp>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is,
+           mersenne_twister_engine<_UI, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
+                                   _Bp, _Tp, _Cp, _Lp, _Fp>& __x)
+{
+    __save_flags<_CharT, _Traits> __lx(__is);
+    __is.flags(ios_base::dec | ios_base::skipws);
+    _UI __t[_Np];
+    for (size_t __i = 0; __i < _Np; ++__i)
+        __is >> __t[__i];
+    if (!__is.fail())
+    {
+        for (size_t __i = 0; __i < _Np; ++__i)
+            __x.__x_[__i] = __t[__i];
+        __x.__i_ = 0;
+    }
+    return __is;
+}
+
+typedef mersenne_twister_engine<uint_fast32_t, 32, 624, 397, 31,
+                                0x9908b0df, 11, 0xffffffff,
+                                7,  0x9d2c5680,
+                                15, 0xefc60000,
+                                18, 1812433253>                         mt19937;
+typedef mersenne_twister_engine<uint_fast64_t, 64, 312, 156, 31,
+                                0xb5026f5aa96619e9ULL, 29, 0x5555555555555555ULL,
+                                17, 0x71d67fffeda60000ULL,
+                                37, 0xfff7eee000000000ULL,
+                                43, 6364136223846793005ULL>          mt19937_64;
+
+// subtract_with_carry_engine
+
+template<class _UIntType, size_t __w, size_t __s, size_t __r>
+class _LIBCPP_TYPE_VIS_ONLY subtract_with_carry_engine;
+
+template<class _UI, size_t _Wp, size_t _Sp, size_t _Rp>
+bool
+operator==(
+    const subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __x,
+    const subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __y);
+
+template<class _UI, size_t _Wp, size_t _Sp, size_t _Rp>
+_LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(
+    const subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __x,
+    const subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __y);
+
+template <class _CharT, class _Traits,
+          class _UI, size_t _Wp, size_t _Sp, size_t _Rp>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os,
+           const subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __x);
+
+template <class _CharT, class _Traits,
+          class _UI, size_t _Wp, size_t _Sp, size_t _Rp>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is,
+           subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __x);
+
+template<class _UIntType, size_t __w, size_t __s, size_t __r>
+class _LIBCPP_TYPE_VIS_ONLY subtract_with_carry_engine
+{
+public:
+    // types
+    typedef _UIntType result_type;
+
+private:
+    result_type __x_[__r];
+    result_type  __c_;
+    size_t      __i_;
+
+    static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
+    static_assert(  0 <  __w, "subtract_with_carry_engine invalid parameters");
+    static_assert(__w <= _Dt, "subtract_with_carry_engine invalid parameters");
+    static_assert(  0 <  __s, "subtract_with_carry_engine invalid parameters");
+    static_assert(__s <  __r, "subtract_with_carry_engine invalid parameters");
+public:
+    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
+    static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
+                                                      (result_type(1) << __w) - result_type(1);
+    static_assert(_Min < _Max, "subtract_with_carry_engine invalid parameters");
+
+    // engine characteristics
+    static _LIBCPP_CONSTEXPR const size_t word_size = __w;
+    static _LIBCPP_CONSTEXPR const size_t short_lag = __s;
+    static _LIBCPP_CONSTEXPR const size_t long_lag = __r;
+    _LIBCPP_INLINE_VISIBILITY
+    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
+    _LIBCPP_INLINE_VISIBILITY
+    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
+    static _LIBCPP_CONSTEXPR const result_type default_seed = 19780503u;
+
+    // constructors and seeding functions
+    _LIBCPP_INLINE_VISIBILITY
+    explicit subtract_with_carry_engine(result_type __sd = default_seed)
+        {seed(__sd);}
+    template<class _Sseq>
+        _LIBCPP_INLINE_VISIBILITY
+        explicit subtract_with_carry_engine(_Sseq& __q,
+        typename enable_if<__is_seed_sequence<_Sseq, subtract_with_carry_engine>::value>::type* = 0)
+        {seed(__q);}
+    _LIBCPP_INLINE_VISIBILITY
+    void seed(result_type __sd = default_seed)
+        {seed(__sd, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
+    template<class _Sseq>
+        _LIBCPP_INLINE_VISIBILITY
+        typename enable_if
+        <
+            __is_seed_sequence<_Sseq, subtract_with_carry_engine>::value,
+            void
+        >::type
+        seed(_Sseq& __q)
+            {__seed(__q, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
+
+    // generating functions
+    result_type operator()();
+    _LIBCPP_INLINE_VISIBILITY
+    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
+
+    template<class _UI, size_t _Wp, size_t _Sp, size_t _Rp>
+    friend
+    bool
+    operator==(
+        const subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __x,
+        const subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __y);
+
+    template<class _UI, size_t _Wp, size_t _Sp, size_t _Rp>
+    friend
+    bool
+    operator!=(
+        const subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __x,
+        const subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __y);
+
+    template <class _CharT, class _Traits,
+              class _UI, size_t _Wp, size_t _Sp, size_t _Rp>
+    friend
+    basic_ostream<_CharT, _Traits>&
+    operator<<(basic_ostream<_CharT, _Traits>& __os,
+               const subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __x);
+
+    template <class _CharT, class _Traits,
+              class _UI, size_t _Wp, size_t _Sp, size_t _Rp>
+    friend
+    basic_istream<_CharT, _Traits>&
+    operator>>(basic_istream<_CharT, _Traits>& __is,
+               subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __x);
+
+private:
+
+    void seed(result_type __sd, integral_constant<unsigned, 1>);
+    void seed(result_type __sd, integral_constant<unsigned, 2>);
+    template<class _Sseq>
+        void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
+    template<class _Sseq>
+        void __seed(_Sseq& __q, integral_constant<unsigned, 2>);
+};
+
+template<class _UIntType, size_t __w, size_t __s, size_t __r>
+    _LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::word_size;
+
+template<class _UIntType, size_t __w, size_t __s, size_t __r>
+    _LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::short_lag;
+
+template<class _UIntType, size_t __w, size_t __s, size_t __r>
+    _LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::long_lag;
+
+template<class _UIntType, size_t __w, size_t __s, size_t __r>
+    _LIBCPP_CONSTEXPR const typename subtract_with_carry_engine<_UIntType, __w, __s, __r>::result_type
+    subtract_with_carry_engine<_UIntType, __w, __s, __r>::default_seed;
+
+template<class _UIntType, size_t __w, size_t __s, size_t __r>
+void
+subtract_with_carry_engine<_UIntType, __w, __s, __r>::seed(result_type __sd,
+        integral_constant<unsigned, 1>)
+{
+    linear_congruential_engine<result_type, 40014u, 0u, 2147483563u>
+        __e(__sd == 0u ? default_seed : __sd);
+    for (size_t __i = 0; __i < __r; ++__i)
+        __x_[__i] = static_cast<result_type>(__e() & _Max);
+    __c_ = __x_[__r-1] == 0;
+    __i_ = 0;
+}
+
+template<class _UIntType, size_t __w, size_t __s, size_t __r>
+void
+subtract_with_carry_engine<_UIntType, __w, __s, __r>::seed(result_type __sd,
+        integral_constant<unsigned, 2>)
+{
+    linear_congruential_engine<result_type, 40014u, 0u, 2147483563u>
+        __e(__sd == 0u ? default_seed : __sd);
+    for (size_t __i = 0; __i < __r; ++__i)
+    {
+        result_type __e0 = __e();
+        __x_[__i] = static_cast<result_type>(
+                                    (__e0 + ((uint64_t)__e() << 32)) & _Max);
+    }
+    __c_ = __x_[__r-1] == 0;
+    __i_ = 0;
+}
+
+template<class _UIntType, size_t __w, size_t __s, size_t __r>
+template<class _Sseq>
+void
+subtract_with_carry_engine<_UIntType, __w, __s, __r>::__seed(_Sseq& __q,
+        integral_constant<unsigned, 1>)
+{
+    const unsigned __k = 1;
+    uint32_t __ar[__r * __k];
+    __q.generate(__ar, __ar + __r * __k);
+    for (size_t __i = 0; __i < __r; ++__i)
+        __x_[__i] = static_cast<result_type>(__ar[__i] & _Max);
+    __c_ = __x_[__r-1] == 0;
+    __i_ = 0;
+}
+
+template<class _UIntType, size_t __w, size_t __s, size_t __r>
+template<class _Sseq>
+void
+subtract_with_carry_engine<_UIntType, __w, __s, __r>::__seed(_Sseq& __q,
+        integral_constant<unsigned, 2>)
+{
+    const unsigned __k = 2;
+    uint32_t __ar[__r * __k];
+    __q.generate(__ar, __ar + __r * __k);
+    for (size_t __i = 0; __i < __r; ++__i)
+        __x_[__i] = static_cast<result_type>(
+                  (__ar[2 * __i] + ((uint64_t)__ar[2 * __i + 1] << 32)) & _Max);
+    __c_ = __x_[__r-1] == 0;
+    __i_ = 0;
+}
+
+template<class _UIntType, size_t __w, size_t __s, size_t __r>
+_UIntType
+subtract_with_carry_engine<_UIntType, __w, __s, __r>::operator()()
+{
+    const result_type& __xs = __x_[(__i_ + (__r - __s)) % __r];
+    result_type& __xr = __x_[__i_];
+    result_type __new_c = __c_ == 0 ? __xs < __xr : __xs != 0 ? __xs <= __xr : 1;
+    __xr = (__xs - __xr - __c_) & _Max;
+    __c_ = __new_c;
+    __i_ = (__i_ + 1) % __r;
+    return __xr;
+}
+
+template<class _UI, size_t _Wp, size_t _Sp, size_t _Rp>
+bool
+operator==(
+    const subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __x,
+    const subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __y)
+{
+    if (__x.__c_ != __y.__c_)
+        return false;
+    if (__x.__i_ == __y.__i_)
+        return _VSTD::equal(__x.__x_, __x.__x_ + _Rp, __y.__x_);
+    if (__x.__i_ == 0 || __y.__i_ == 0)
+    {
+        size_t __j = _VSTD::min(_Rp - __x.__i_, _Rp - __y.__i_);
+        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + __x.__i_ + __j,
+                         __y.__x_ + __y.__i_))
+            return false;
+        if (__x.__i_ == 0)
+            return _VSTD::equal(__x.__x_ + __j, __x.__x_ + _Rp, __y.__x_);
+        return _VSTD::equal(__x.__x_, __x.__x_ + (_Rp - __j), __y.__x_ + __j);
+    }
+    if (__x.__i_ < __y.__i_)
+    {
+        size_t __j = _Rp - __y.__i_;
+        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + (__x.__i_ + __j),
+                         __y.__x_ + __y.__i_))
+            return false;
+        if (!_VSTD::equal(__x.__x_ + (__x.__i_ + __j), __x.__x_ + _Rp,
+                         __y.__x_))
+            return false;
+        return _VSTD::equal(__x.__x_, __x.__x_ + __x.__i_,
+                           __y.__x_ + (_Rp - (__x.__i_ + __j)));
+    }
+    size_t __j = _Rp - __x.__i_;
+    if (!_VSTD::equal(__y.__x_ + __y.__i_, __y.__x_ + (__y.__i_ + __j),
+                     __x.__x_ + __x.__i_))
+        return false;
+    if (!_VSTD::equal(__y.__x_ + (__y.__i_ + __j), __y.__x_ + _Rp,
+                     __x.__x_))
+        return false;
+    return _VSTD::equal(__y.__x_, __y.__x_ + __y.__i_,
+                       __x.__x_ + (_Rp - (__y.__i_ + __j)));
+}
+
+template<class _UI, size_t _Wp, size_t _Sp, size_t _Rp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(
+    const subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __x,
+    const subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __y)
+{
+    return !(__x == __y);
+}
+
+template <class _CharT, class _Traits,
+          class _UI, size_t _Wp, size_t _Sp, size_t _Rp>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os,
+           const subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __x)
+{
+    __save_flags<_CharT, _Traits> __lx(__os);
+    __os.flags(ios_base::dec | ios_base::left);
+    _CharT __sp = __os.widen(' ');
+    __os.fill(__sp);
+    __os << __x.__x_[__x.__i_];
+    for (size_t __j = __x.__i_ + 1; __j < _Rp; ++__j)
+        __os << __sp << __x.__x_[__j];
+    for (size_t __j = 0; __j < __x.__i_; ++__j)
+        __os << __sp << __x.__x_[__j];
+    __os << __sp << __x.__c_;
+    return __os;
+}
+
+template <class _CharT, class _Traits,
+          class _UI, size_t _Wp, size_t _Sp, size_t _Rp>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is,
+           subtract_with_carry_engine<_UI, _Wp, _Sp, _Rp>& __x)
+{
+    __save_flags<_CharT, _Traits> __lx(__is);
+    __is.flags(ios_base::dec | ios_base::skipws);
+    _UI __t[_Rp+1];
+    for (size_t __i = 0; __i < _Rp+1; ++__i)
+        __is >> __t[__i];
+    if (!__is.fail())
+    {
+        for (size_t __i = 0; __i < _Rp; ++__i)
+            __x.__x_[__i] = __t[__i];
+        __x.__c_ = __t[_Rp];
+        __x.__i_ = 0;
+    }
+    return __is;
+}
+
+typedef subtract_with_carry_engine<uint_fast32_t, 24, 10, 24>     ranlux24_base;
+typedef subtract_with_carry_engine<uint_fast64_t, 48,  5, 12>     ranlux48_base;
+
+// discard_block_engine
+
+template<class _Engine, size_t __p, size_t __r>
+class _LIBCPP_TYPE_VIS_ONLY discard_block_engine
+{
+    _Engine __e_;
+    int     __n_;
+
+    static_assert(  0 <  __r, "discard_block_engine invalid parameters");
+    static_assert(__r <= __p, "discard_block_engine invalid parameters");
+public:
+    // types
+    typedef typename _Engine::result_type result_type;
+
+    // engine characteristics
+    static _LIBCPP_CONSTEXPR const size_t block_size = __p;
+    static _LIBCPP_CONSTEXPR const size_t used_block = __r;
+
+#ifdef _LIBCPP_HAS_NO_CONSTEXPR
+    static const result_type _Min = _Engine::_Min;
+    static const result_type _Max = _Engine::_Max;
+#else
+    static _LIBCPP_CONSTEXPR const result_type _Min = _Engine::min();
+    static _LIBCPP_CONSTEXPR const result_type _Max = _Engine::max();
+#endif
+
+    _LIBCPP_INLINE_VISIBILITY
+    static _LIBCPP_CONSTEXPR result_type min() { return _Engine::min(); }
+    _LIBCPP_INLINE_VISIBILITY
+    static _LIBCPP_CONSTEXPR result_type max() { return _Engine::max(); }
+
+    // constructors and seeding functions
+    _LIBCPP_INLINE_VISIBILITY
+    discard_block_engine() : __n_(0) {}
+    _LIBCPP_INLINE_VISIBILITY
+    explicit discard_block_engine(const _Engine& __e)
+        : __e_(__e), __n_(0) {}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    explicit discard_block_engine(_Engine&& __e)
+        : __e_(_VSTD::move(__e)), __n_(0) {}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    explicit discard_block_engine(result_type __sd) : __e_(__sd), __n_(0) {}
+    template<class _Sseq>
+        _LIBCPP_INLINE_VISIBILITY
+        explicit discard_block_engine(_Sseq& __q,
+        typename enable_if<__is_seed_sequence<_Sseq, discard_block_engine>::value &&
+                           !is_convertible<_Sseq, _Engine>::value>::type* = 0)
+        : __e_(__q), __n_(0) {}
+    _LIBCPP_INLINE_VISIBILITY
+    void seed() {__e_.seed(); __n_ = 0;}
+    _LIBCPP_INLINE_VISIBILITY
+    void seed(result_type __sd) {__e_.seed(__sd); __n_ = 0;}
+    template<class _Sseq>
+        _LIBCPP_INLINE_VISIBILITY
+        typename enable_if
+        <
+            __is_seed_sequence<_Sseq, discard_block_engine>::value,
+            void
+        >::type
+        seed(_Sseq& __q) {__e_.seed(__q); __n_ = 0;}
+
+    // generating functions
+    result_type operator()();
+    _LIBCPP_INLINE_VISIBILITY
+    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
+
+    // property functions
+    _LIBCPP_INLINE_VISIBILITY
+    const _Engine& base() const _NOEXCEPT {return __e_;}
+
+    template<class _Eng, size_t _Pp, size_t _Rp>
+    friend
+    bool
+    operator==(
+        const discard_block_engine<_Eng, _Pp, _Rp>& __x,
+        const discard_block_engine<_Eng, _Pp, _Rp>& __y);
+
+    template<class _Eng, size_t _Pp, size_t _Rp>
+    friend
+    bool
+    operator!=(
+        const discard_block_engine<_Eng, _Pp, _Rp>& __x,
+        const discard_block_engine<_Eng, _Pp, _Rp>& __y);
+
+    template <class _CharT, class _Traits,
+              class _Eng, size_t _Pp, size_t _Rp>
+    friend
+    basic_ostream<_CharT, _Traits>&
+    operator<<(basic_ostream<_CharT, _Traits>& __os,
+               const discard_block_engine<_Eng, _Pp, _Rp>& __x);
+
+    template <class _CharT, class _Traits,
+              class _Eng, size_t _Pp, size_t _Rp>
+    friend
+    basic_istream<_CharT, _Traits>&
+    operator>>(basic_istream<_CharT, _Traits>& __is,
+               discard_block_engine<_Eng, _Pp, _Rp>& __x);
+};
+
+template<class _Engine, size_t __p, size_t __r>
+    _LIBCPP_CONSTEXPR const size_t discard_block_engine<_Engine, __p, __r>::block_size;
+
+template<class _Engine, size_t __p, size_t __r>
+    _LIBCPP_CONSTEXPR const size_t discard_block_engine<_Engine, __p, __r>::used_block;
+
+template<class _Engine, size_t __p, size_t __r>
+typename discard_block_engine<_Engine, __p, __r>::result_type
+discard_block_engine<_Engine, __p, __r>::operator()()
+{
+    if (__n_ >= __r)
+    {
+        __e_.discard(__p - __r);
+        __n_ = 0;
+    }
+    ++__n_;
+    return __e_();
+}
+
+template<class _Eng, size_t _Pp, size_t _Rp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator==(const discard_block_engine<_Eng, _Pp, _Rp>& __x,
+           const discard_block_engine<_Eng, _Pp, _Rp>& __y)
+{
+    return __x.__n_ == __y.__n_ && __x.__e_ == __y.__e_;
+}
+
+template<class _Eng, size_t _Pp, size_t _Rp>
+inline _LIBCPP_INLINE_VISIBILITY
+bool
+operator!=(const discard_block_engine<_Eng, _Pp, _Rp>& __x,
+           const discard_block_engine<_Eng, _Pp, _Rp>& __y)
+{
+    return !(__x == __y);
+}
+
+template <class _CharT, class _Traits,
+          class _Eng, size_t _Pp, size_t _Rp>
+basic_ostream<_CharT, _Traits>&
+operator<<(basic_ostream<_CharT, _Traits>& __os,
+           const discard_block_engine<_Eng, _Pp, _Rp>& __x)
+{
+    __save_flags<_CharT, _Traits> __lx(__os);
+    __os.flags(ios_base::dec | ios_base::left);
+    _CharT __sp = __os.widen(' ');
+    __os.fill(__sp);
+    return __os << __x.__e_ << __sp << __x.__n_;
+}
+
+template <class _CharT, class _Traits,
+          class _Eng, size_t _Pp, size_t _Rp>
+basic_istream<_CharT, _Traits>&
+operator>>(basic_istream<_CharT, _Traits>& __is,
+           discard_block_engine<_Eng, _Pp, _Rp>& __x)
+{
+    __save_flags<_CharT, _Traits> __lx(__is);
+    __is.flags(ios_base::dec | ios_base::skipws);
+    _Eng __e;
+    int __n;
+    __is >> __e >> __n;
+    if (!__is.fail())
+    {
+        __x.__e_ = __e;
+        __x.__n_ = __n;
+    }
+    return __is;
+}
+
+typedef discard_block_engine<ranlux24_base, 223, 23> ranlux24;
+typedef discard_block_engine<ranlux48_base, 389, 11> ranlux48;
+
+// independent_bits_engine
+
+template<class _Engine, size_t __w, class _UIntType>
+class _LIBCPP_TYPE_VIS_ONLY independent_bits_engine
+{
+    template <class _UI, _UI _R0, size_t _Wp, size_t _Mp>
+    class __get_n
+    {
+        static _LIBCPP_CONSTEXPR const size_t _Dt = numeric_limits<_UI>::digits;
+        static _LIBCPP_CONSTEXPR const size_t _Np = _Wp / _Mp + (_Wp % _Mp != 0);
+        static _LIBCPP_CONSTEXPR const size_t _W0 = _Wp / _Np;
+        static _LIBCPP_CONSTEXPR const _UI _Y0 = _W0 >= _Dt ? 0 : (_R0 >> _W0) << _W0;
+    public:
+        static _LIBCPP_CONSTEXPR const size_t value = _R0 - _Y0 > _Y0 / _Np ? _Np + 1 : _Np;
+    };
+public:
+    // types
+    typedef _UIntType result_type;
+
+private:
+    _Engine __e_;
+
+    static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
+    static_assert(  0 <  __w, "independent_bits_engine invalid parameters");
+    static_assert(__w <= _Dt, "independent_bits_engine invalid parameters");
+
+    typedef typename _Engine::result_type _Engine_result_type;
+    typedef typename conditional
+        <
+            sizeof(_Engine_result_type) <= sizeof(result_type),
+                result_type,
+                _Engine_result_type
+        >::type _Working_result_type;
+#ifdef _LIBCPP_HAS_NO_CONSTEXPR
+    static const _Working_result_type _Rp = _Engine::_Max - _Engine::_Min
+                                          + _Working_result_type(1);
+#else
+    static _LIBCPP_CONSTEXPR const _Working_result_type _Rp = _Engine::max() - _Engine::min()
+                                                            + _Working_result_type(1);
+#endif
+    static _LIBCPP_CONSTEXPR const size_t __m = __log2<_Working_result_type, _Rp>::value;
+    static _LIBCPP_CONSTEXPR const size_t __n = __get_n<_Working_result_type, _Rp, __w, __m>::value;
+    static _LIBCPP_CONSTEXPR const size_t __w0 = __w / __n;
+    static _LIBCPP_CONSTEXPR const size_t __n0 = __n - __w % __n;
+    static _LIBCPP_CONSTEXPR const size_t _WDt = numeric_limits<_Working_result_type>::digits;
+    static _LIBCPP_CONSTEXPR const size_t _EDt = numeric_limits<_Engine_result_type>::digits;
+    static _LIBCPP_CONSTEXPR const _Working_result_type __y0 = __w0 >= _WDt ? 0 :
+                                                               (_Rp >> __w0) << __w0;
+    static _LIBCPP_CONSTEXPR const _Working_result_type __y1 = __w0 >= _WDt - 1 ? 0 :
+                                                               (_Rp >> (__w0+1)) << (__w0+1);
+    static _LIBCPP_CONSTEXPR const _Engine_result_type __mask0 = __w0 > 0 ?
+                                _Engine_result_type(~0) >> (_EDt - __w0) :
+                                _Engine_result_type(0);
+    static _LIBCPP_CONSTEXPR const _Engine_result_type __mask1 = __w0 < _EDt - 1 ?
+                                _Engine_result_type(~0) >> (_EDt - (__w0 + 1)) :
+                                _Engine_result_type(~0);
+public:
+    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
+    static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
+                                                      (result_type(1) << __w) - result_type(1);
+    static_assert(_Min < _Max, "independent_bits_engine invalid parameters");
+
+    // engine characteristics
+    _LIBCPP_INLINE_VISIBILITY
+    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
+    _LIBCPP_INLINE_VISIBILITY
+    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
+
+    // constructors and seeding functions
+    _LIBCPP_INLINE_VISIBILITY
+    independent_bits_engine() {}
+    _LIBCPP_INLINE_VISIBILITY
+    explicit independent_bits_engine(const _Engine& __e)
+        : __e_(__e) {}
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    explicit independent_bits_engine(_Engine&& __e)
+        : __e_(_VSTD::move(__e)) {}
+#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    _LIBCPP_INLINE_VISIBILITY
+    explicit independent_bits_engine(result_type __sd) : __e_(__sd) {}
+    template<class _Sseq>
+        _LIBCPP_INLINE_VISIBILITY
+        explicit independent_bits_engine(_Sseq& __q,
+        typename enable_if<__is_seed_sequence<_Sseq, independent_bits_engine>::value &&
+                           !is_convertible<_Sseq, _Engine>::value>::type* = 0)
+         : __e_(__q) {}
+    _LIBCPP_INLINE_VISIBILITY
+    void seed() {__e_.seed();}
+    _LIBCPP_INLINE_VISIBILITY
+    void seed(result_type __sd) {__e_.seed(__sd);}
+    template<class _Sseq>
+        _LIBCPP_INLINE_VISIBILITY
+        typename enable_if
+        <
+            __is_seed_sequence<_Sseq, independent_bits_engine>::value,
+            void
+        >::type
+        seed(_Sseq& __q) {__e_.seed(__q);}
+
+    // generating functions
+    _LIBCPP_INLINE_VISIBILITY
+    result_type operator()() {return __eval(integral_constant<bool, _Rp != 0>());}
+    _LIBCPP_INLINE_VISIBILITY
+    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
+
+    // property functions
+    _LIBCPP_INLINE_VISIBILITY
+    const _Engine& base() const _NOEXCEPT {return __e_;}
+
+    template<class _Eng, size_t _Wp, class _UI>
+    friend
+    bool
+    operator==(
+        const independent_bits_engine<_Eng, _Wp, _UI>& __x,
+        const independent_bits_engine<_Eng, _Wp, _UI>& __y);
+
+    template<class _Eng, size_t _Wp, class _UI>
+    friend
+    bool
+    operator!=(
+        const independent_bits_engine<_Eng, _Wp, _UI>& __x,
+        const independent_bits_engine<_Eng, _Wp, _UI>& __y);
+
+    template <class _CharT, class _Traits,
+              class _Eng, size_t _Wp, class _UI>
+    friend
+    basic_ostream<_CharT, _Traits>&
+    operator<<(basic_ostream<_CharT, _Traits>& __os,
+               const independent_bits_eng