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// -*- 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___CXX03___FUNCTIONAL_INVOKE_H
#define _LIBCPP___CXX03___FUNCTIONAL_INVOKE_H
#include <__cxx03/__config>
#include <__cxx03/__type_traits/invoke.h>
#include <__cxx03/__utility/forward.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER >= 17
template <class _Fn, class... _Args>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 invoke_result_t<_Fn, _Args...>
invoke(_Fn&& __f, _Args&&... __args) noexcept(is_nothrow_invocable_v<_Fn, _Args...>) {
return std::__invoke(std::forward<_Fn>(__f), std::forward<_Args>(__args)...);
}
#endif // _LIBCPP_STD_VER >= 17
#if _LIBCPP_STD_VER >= 23
template <class _Result, class _Fn, class... _Args>
requires is_invocable_r_v<_Result, _Fn, _Args...>
_LIBCPP_HIDE_FROM_ABI constexpr _Result
invoke_r(_Fn&& __f, _Args&&... __args) noexcept(is_nothrow_invocable_r_v<_Result, _Fn, _Args...>) {
if constexpr (is_void_v<_Result>) {
static_cast<void>(std::invoke(std::forward<_Fn>(__f), std::forward<_Args>(__args)...));
} else {
// TODO: Use reference_converts_from_temporary_v once implemented
// using _ImplicitInvokeResult = invoke_result_t<_Fn, _Args...>;
// static_assert(!reference_converts_from_temporary_v<_Result, _ImplicitInvokeResult>,
static_assert(true,
"Returning from invoke_r would bind a temporary object to the reference return type, "
"which would result in a dangling reference.");
return std::invoke(std::forward<_Fn>(__f), std::forward<_Args>(__args)...);
}
}
#endif
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___CXX03___FUNCTIONAL_INVOKE_H
|
