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-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef _LIBCPP___FUNCTIONAL_MEM_FN_H 11 #define _LIBCPP___FUNCTIONAL_MEM_FN_H 12 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_header 21 #endif 22 23 _LIBCPP_BEGIN_NAMESPACE_STD 24 25 template <class _Tp> 26 class __mem_fn : public __weak_result_type<_Tp> { 27 public: 28 // types 29 typedef _Tp type; 30 31 private: 32 type __f_; 33 34 public: 35 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __mem_fn(type __f) _NOEXCEPT : __f_(__f) {} 36 37 // invoke 38 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 45 template <class _Rp, class _Tp> 46 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __mem_fn<_Rp _Tp::*> mem_fn(_Rp _Tp::*__pm) _NOEXCEPT { 47 return __mem_fn<_Rp _Tp::*>(__pm); 48 } 49 50 _LIBCPP_END_NAMESPACE_STD 51 52 #endif // _LIBCPP___FUNCTIONAL_MEM_FN_H 53