| // -*- C++ -*- |
| //===----------------------------------------------------------------------===// |
| // |
| // 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___FUNCTIONAL_REFERENCE_WRAPPER_H |
| #define _LIBCPP___FUNCTIONAL_REFERENCE_WRAPPER_H |
| |
| #include <__config> |
| #include <__functional/weak_result_type.h> |
| #include <__memory/addressof.h> |
| #include <__utility/forward.h> |
| #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_TEMPLATE_VIS reference_wrapper |
| #if _LIBCPP_STD_VER <= 17 || !defined(_LIBCPP_ABI_NO_BINDER_BASES) |
| : public __weak_result_type<_Tp> |
| #endif |
| { |
| public: |
| // types |
| typedef _Tp type; |
| private: |
| type* __f_; |
| |
| static void __fun(_Tp&) _NOEXCEPT; |
| static void __fun(_Tp&&) = delete; |
| |
| public: |
| template <class _Up, class = __enable_if_t<!__is_same_uncvref<_Up, reference_wrapper>::value, decltype(__fun(declval<_Up>())) > > |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 |
| reference_wrapper(_Up&& __u) _NOEXCEPT_(noexcept(__fun(declval<_Up>()))) { |
| type& __f = static_cast<_Up&&>(__u); |
| __f_ = _VSTD::addressof(__f); |
| } |
| |
| // access |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 |
| operator type&() const _NOEXCEPT {return *__f_;} |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 |
| type& get() const _NOEXCEPT {return *__f_;} |
| |
| // invoke |
| template <class... _ArgTypes> |
| _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 |
| typename __invoke_of<type&, _ArgTypes...>::type |
| operator() (_ArgTypes&&... __args) const { |
| return std::__invoke(get(), std::forward<_ArgTypes>(__args)...); |
| } |
| }; |
| |
| #if _LIBCPP_STD_VER > 14 |
| template <class _Tp> |
| reference_wrapper(_Tp&) -> reference_wrapper<_Tp>; |
| #endif |
| |
| template <class _Tp> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 |
| reference_wrapper<_Tp> |
| ref(_Tp& __t) _NOEXCEPT |
| { |
| return reference_wrapper<_Tp>(__t); |
| } |
| |
| template <class _Tp> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 |
| reference_wrapper<_Tp> |
| ref(reference_wrapper<_Tp> __t) _NOEXCEPT |
| { |
| return __t; |
| } |
| |
| template <class _Tp> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 |
| reference_wrapper<const _Tp> |
| cref(const _Tp& __t) _NOEXCEPT |
| { |
| return reference_wrapper<const _Tp>(__t); |
| } |
| |
| template <class _Tp> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 |
| reference_wrapper<const _Tp> |
| cref(reference_wrapper<_Tp> __t) _NOEXCEPT |
| { |
| return __t; |
| } |
| |
| template <class _Tp> void ref(const _Tp&&) = delete; |
| template <class _Tp> void cref(const _Tp&&) = delete; |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___FUNCTIONAL_REFERENCE_WRAPPER_H |
