| // -*- 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___FUNCTIONAL_INVOKE_H |
| #define _LIBCPP___FUNCTIONAL_INVOKE_H |
| |
| #include <__config> |
| #include <__type_traits/invoke.h> |
| #include <__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 _VSTD::__invoke(_VSTD::forward<_Fn>(__f), _VSTD::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___FUNCTIONAL_INVOKE_H |