// Implementation of INVOKE -*- C++ -*- // Copyright (C) 2016-2018 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // Under Section 7 of GPL version 3, you are granted additional // permissions described in the GCC Runtime Library Exception, version // 3.1, as published by the Free Software Foundation. // You should have received a copy of the GNU General Public License and // a copy of the GCC Runtime Library Exception along with this program; // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see // . /** @file include/bits/invoke.h * This is an internal header file, included by other library headers. * Do not attempt to use it directly. @headername{functional} */ #ifndef _GLIBCXX_INVOKE_H #define _GLIBCXX_INVOKE_H 1 #pragma GCC system_header #if __cplusplus < 201103L # include #else #include namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION /** * @addtogroup utilities * @{ */ // Used by __invoke_impl instead of std::forward<_Tp> so that a // reference_wrapper is converted to an lvalue-reference. template::type> constexpr _Up&& __invfwd(typename remove_reference<_Tp>::type& __t) noexcept { return static_cast<_Up&&>(__t); } template constexpr _Res __invoke_impl(__invoke_other, _Fn&& __f, _Args&&... __args) { return std::forward<_Fn>(__f)(std::forward<_Args>(__args)...); } template constexpr _Res __invoke_impl(__invoke_memfun_ref, _MemFun&& __f, _Tp&& __t, _Args&&... __args) { return (__invfwd<_Tp>(__t).*__f)(std::forward<_Args>(__args)...); } template constexpr _Res __invoke_impl(__invoke_memfun_deref, _MemFun&& __f, _Tp&& __t, _Args&&... __args) { return ((*std::forward<_Tp>(__t)).*__f)(std::forward<_Args>(__args)...); } template constexpr _Res __invoke_impl(__invoke_memobj_ref, _MemPtr&& __f, _Tp&& __t) { return __invfwd<_Tp>(__t).*__f; } template constexpr _Res __invoke_impl(__invoke_memobj_deref, _MemPtr&& __f, _Tp&& __t) { return (*std::forward<_Tp>(__t)).*__f; } /// Invoke a callable object. template constexpr typename __invoke_result<_Callable, _Args...>::type __invoke(_Callable&& __fn, _Args&&... __args) noexcept(__is_nothrow_invocable<_Callable, _Args...>::value) { using __result = __invoke_result<_Callable, _Args...>; using __type = typename __result::type; using __tag = typename __result::__invoke_type; return std::__invoke_impl<__type>(__tag{}, std::forward<_Callable>(__fn), std::forward<_Args>(__args)...); } _GLIBCXX_END_NAMESPACE_VERSION } // namespace std #endif // C++11 #endif // _GLIBCXX_INVOKE_H