xref: /openbsd-src/gnu/llvm/libcxx/include/__concepts/invocable.h (revision 4bdff4bed0e3d54e55670334c7d0077db4170f86)
1*4bdff4beSrobert //===----------------------------------------------------------------------===//
2*4bdff4beSrobert //
3*4bdff4beSrobert // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*4bdff4beSrobert // See https://llvm.org/LICENSE.txt for license information.
5*4bdff4beSrobert // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*4bdff4beSrobert //
7*4bdff4beSrobert //===----------------------------------------------------------------------===//
8*4bdff4beSrobert 
9*4bdff4beSrobert #ifndef _LIBCPP___CONCEPTS_INVOCABLE_H
10*4bdff4beSrobert #define _LIBCPP___CONCEPTS_INVOCABLE_H
11*4bdff4beSrobert 
12*4bdff4beSrobert #include <__config>
13*4bdff4beSrobert #include <__functional/invoke.h>
14*4bdff4beSrobert #include <__utility/forward.h>
15*4bdff4beSrobert 
16*4bdff4beSrobert #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
17*4bdff4beSrobert #  pragma GCC system_header
18*4bdff4beSrobert #endif
19*4bdff4beSrobert 
20*4bdff4beSrobert _LIBCPP_BEGIN_NAMESPACE_STD
21*4bdff4beSrobert 
22*4bdff4beSrobert #if _LIBCPP_STD_VER > 17
23*4bdff4beSrobert 
24*4bdff4beSrobert // [concept.invocable]
25*4bdff4beSrobert 
26*4bdff4beSrobert template<class _Fn, class... _Args>
requires(_Fn && __fn,_Args &&...__args)27*4bdff4beSrobert concept invocable = requires(_Fn&& __fn, _Args&&... __args) {
28*4bdff4beSrobert   _VSTD::invoke(_VSTD::forward<_Fn>(__fn), _VSTD::forward<_Args>(__args)...); // not required to be equality preserving
29*4bdff4beSrobert };
30*4bdff4beSrobert 
31*4bdff4beSrobert // [concept.regular.invocable]
32*4bdff4beSrobert 
33*4bdff4beSrobert template<class _Fn, class... _Args>
34*4bdff4beSrobert concept regular_invocable = invocable<_Fn, _Args...>;
35*4bdff4beSrobert 
36*4bdff4beSrobert #endif // _LIBCPP_STD_VER > 17
37*4bdff4beSrobert 
38*4bdff4beSrobert _LIBCPP_END_NAMESPACE_STD
39*4bdff4beSrobert 
40*4bdff4beSrobert #endif // _LIBCPP___CONCEPTS_INVOCABLE_H
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