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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_INVOKE_H11#define _LIBCPP___FUNCTIONAL_INVOKE_H12 13#include <__config>14#include <__type_traits/invoke.h>15#include <__type_traits/is_void.h>16#include <__utility/forward.h>17 18#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)19# pragma GCC system_header20#endif21 22_LIBCPP_BEGIN_NAMESPACE_STD23 24#if _LIBCPP_STD_VER >= 1725 26template <class _Fn, class... _Args>27_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 invoke_result_t<_Fn, _Args...>28invoke(_Fn&& __f, _Args&&... __args) noexcept(is_nothrow_invocable_v<_Fn, _Args...>) {29 return std::__invoke(std::forward<_Fn>(__f), std::forward<_Args>(__args)...);30}31 32#endif // _LIBCPP_STD_VER >= 1733 34#if _LIBCPP_STD_VER >= 2335template <class _Result, class _Fn, class... _Args>36 requires is_invocable_r_v<_Result, _Fn, _Args...>37_LIBCPP_HIDE_FROM_ABI constexpr _Result38invoke_r(_Fn&& __f, _Args&&... __args) noexcept(is_nothrow_invocable_r_v<_Result, _Fn, _Args...>) {39 if constexpr (is_void_v<_Result>) {40 static_cast<void>(std::invoke(std::forward<_Fn>(__f), std::forward<_Args>(__args)...));41 } else {42 // TODO: Use reference_converts_from_temporary_v once implemented43 // using _ImplicitInvokeResult = invoke_result_t<_Fn, _Args...>;44 // static_assert(!reference_converts_from_temporary_v<_Result, _ImplicitInvokeResult>,45 static_assert(true,46 "Returning from invoke_r would bind a temporary object to the reference return type, "47 "which would result in a dangling reference.");48 return std::invoke(std::forward<_Fn>(__f), std::forward<_Args>(__args)...);49 }50}51#endif52 53_LIBCPP_END_NAMESPACE_STD54 55#endif // _LIBCPP___FUNCTIONAL_INVOKE_H56