1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___CONCEPTS_INVOCABLE_H 10 #define _LIBCPP___CONCEPTS_INVOCABLE_H 11 12 #include <__config> 13 #include <__functional/invoke.h> 14 #include <__utility/forward.h> 15 #include <type_traits> 16 17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 18 # pragma GCC system_header 19 #endif 20 21 _LIBCPP_BEGIN_NAMESPACE_STD 22 23 #if _LIBCPP_STD_VER > 17 24 25 // [concept.invocable] 26 27 template<class _Fn, class... _Args> 28 concept invocable = requires(_Fn&& __fn, _Args&&... __args) { 29 _VSTD::invoke(_VSTD::forward<_Fn>(__fn), _VSTD::forward<_Args>(__args)...); // not required to be equality preserving 30 }; 31 32 // [concept.regular.invocable] 33 34 template<class _Fn, class... _Args> 35 concept regular_invocable = invocable<_Fn, _Args...>; 36 37 #endif // _LIBCPP_STD_VER > 17 38 39 _LIBCPP_END_NAMESPACE_STD 40 41 #endif // _LIBCPP___CONCEPTS_INVOCABLE_H 42