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1// -*- C++ -*-2//===----------------------------------------------------------------------===//3//4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.5// See https://llvm.org/LICENSE.txt for license information.6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception7//8//===----------------------------------------------------------------------===//9 10#ifndef _LIBCPP___FUNCTIONAL_MEM_FN_H11#define _LIBCPP___FUNCTIONAL_MEM_FN_H12 13#include <__config>14#include <__functional/binary_function.h>15#include <__functional/weak_result_type.h>16#include <__type_traits/invoke.h>17#include <__utility/forward.h>18 19#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)20# pragma GCC system_header21#endif22 23_LIBCPP_BEGIN_NAMESPACE_STD24 25template <class _Tp>26class __mem_fn : public __weak_result_type<_Tp> {27public:28 // types29 typedef _Tp type;30 31private:32 type __f_;33 34public:35 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __mem_fn(type __f) _NOEXCEPT : __f_(__f) {}36 37 // invoke38 template <class... _ArgTypes>39 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __invoke_result_t<const _Tp&, _ArgTypes...>40 operator()(_ArgTypes&&... __args) const _NOEXCEPT_(__is_nothrow_invocable_v<const _Tp&, _ArgTypes...>) {41 return std::__invoke(__f_, std::forward<_ArgTypes>(__args)...);42 }43};44 45template <class _Rp, class _Tp>46[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __mem_fn<_Rp _Tp::*>47mem_fn(_Rp _Tp::* __pm) _NOEXCEPT {48 return __mem_fn<_Rp _Tp::*>(__pm);49}50 51_LIBCPP_END_NAMESPACE_STD52 53#endif // _LIBCPP___FUNCTIONAL_MEM_FN_H54