| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef _LIBCPP___RANDOM_DISCARD_BLOCK_ENGINE_H |
| #define _LIBCPP___RANDOM_DISCARD_BLOCK_ENGINE_H |
| |
| #include <__config> |
| #include <__random/is_seed_sequence.h> |
| #include <__utility/move.h> |
| #include <climits> |
| #include <iosfwd> |
| #include <type_traits> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| #pragma GCC system_header |
| #endif |
| |
| _LIBCPP_PUSH_MACROS |
| #include <__undef_macros> |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| template<class _Engine, size_t __p, size_t __r> |
| class _LIBCPP_TEMPLATE_VIS 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"); |
| static_assert(__r <= INT_MAX, "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_CXX03_LANG |
| 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_CXX03_LANG |
| _LIBCPP_INLINE_VISIBILITY |
| explicit discard_block_engine(_Engine&& __e) |
| : __e_(_VSTD::move(__e)), __n_(0) {} |
| #endif // _LIBCPP_CXX03_LANG |
| _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_ >= static_cast<int>(__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); |
| typedef basic_ostream<_CharT, _Traits> _Ostream; |
| __os.flags(_Ostream::dec | _Ostream::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); |
| typedef basic_istream<_CharT, _Traits> _Istream; |
| __is.flags(_Istream::dec | _Istream::skipws); |
| _Eng __e; |
| int __n; |
| __is >> __e >> __n; |
| if (!__is.fail()) |
| { |
| __x.__e_ = __e; |
| __x.__n_ = __n; |
| } |
| return __is; |
| } |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| _LIBCPP_POP_MACROS |
| |
| #endif // _LIBCPP___RANDOM_DISCARD_BLOCK_ENGINE_H |
