xref: /freebsd-src/contrib/llvm-project/libcxx/include/__concepts/invocable.h (revision 5f757f3ff9144b609b3c433dfd370cc6bdc191ad)
1349cc55cSDimitry Andric //===----------------------------------------------------------------------===//
2349cc55cSDimitry Andric //
3349cc55cSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4349cc55cSDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
5349cc55cSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6349cc55cSDimitry Andric //
7349cc55cSDimitry Andric //===----------------------------------------------------------------------===//
8349cc55cSDimitry Andric 
9349cc55cSDimitry Andric #ifndef _LIBCPP___CONCEPTS_INVOCABLE_H
10349cc55cSDimitry Andric #define _LIBCPP___CONCEPTS_INVOCABLE_H
11349cc55cSDimitry Andric 
12349cc55cSDimitry Andric #include <__config>
13349cc55cSDimitry Andric #include <__functional/invoke.h>
14349cc55cSDimitry Andric #include <__utility/forward.h>
15349cc55cSDimitry Andric 
16349cc55cSDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
17349cc55cSDimitry Andric #  pragma GCC system_header
18349cc55cSDimitry Andric #endif
19349cc55cSDimitry Andric 
20349cc55cSDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
21349cc55cSDimitry Andric 
2206c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 20
23349cc55cSDimitry Andric 
24349cc55cSDimitry Andric // [concept.invocable]
25349cc55cSDimitry Andric 
26349cc55cSDimitry Andric template <class _Fn, class... _Args>
requires(_Fn && __fn,_Args &&...__args)27349cc55cSDimitry Andric concept invocable = requires(_Fn&& __fn, _Args&&... __args) {
28*5f757f3fSDimitry Andric   std::invoke(std::forward<_Fn>(__fn), std::forward<_Args>(__args)...); // not required to be equality preserving
29349cc55cSDimitry Andric };
30349cc55cSDimitry Andric 
31349cc55cSDimitry Andric // [concept.regular.invocable]
32349cc55cSDimitry Andric 
33349cc55cSDimitry Andric template <class _Fn, class... _Args>
34349cc55cSDimitry Andric concept regular_invocable = invocable<_Fn, _Args...>;
35349cc55cSDimitry Andric 
3606c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 20
37349cc55cSDimitry Andric 
38349cc55cSDimitry Andric _LIBCPP_END_NAMESPACE_STD
39349cc55cSDimitry Andric 
40349cc55cSDimitry Andric #endif // _LIBCPP___CONCEPTS_INVOCABLE_H
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