xref: /freebsd-src/contrib/llvm-project/libcxx/include/__functional/not_fn.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1fe6060f1SDimitry Andric // -*- C++ -*-
2fe6060f1SDimitry Andric //===----------------------------------------------------------------------===//
3fe6060f1SDimitry Andric //
4fe6060f1SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5fe6060f1SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
6fe6060f1SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7fe6060f1SDimitry Andric //
8fe6060f1SDimitry Andric //===----------------------------------------------------------------------===//
9fe6060f1SDimitry Andric 
10fe6060f1SDimitry Andric #ifndef _LIBCPP___FUNCTIONAL_NOT_FN_H
11fe6060f1SDimitry Andric #define _LIBCPP___FUNCTIONAL_NOT_FN_H
12fe6060f1SDimitry Andric 
13fe6060f1SDimitry Andric #include <__config>
14fe6060f1SDimitry Andric #include <__functional/invoke.h>
1504eeddc0SDimitry Andric #include <__functional/perfect_forward.h>
1606c3fb27SDimitry Andric #include <__type_traits/decay.h>
1706c3fb27SDimitry Andric #include <__type_traits/enable_if.h>
1806c3fb27SDimitry Andric #include <__type_traits/is_constructible.h>
1981ad6265SDimitry Andric #include <__utility/forward.h>
20fe6060f1SDimitry Andric 
21fe6060f1SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
22fe6060f1SDimitry Andric #  pragma GCC system_header
23fe6060f1SDimitry Andric #endif
24fe6060f1SDimitry Andric 
25fe6060f1SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
26fe6060f1SDimitry Andric 
2706c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 17
28fe6060f1SDimitry Andric 
29349cc55cSDimitry Andric struct __not_fn_op {
30fe6060f1SDimitry Andric   template <class... _Args>
31*cb14a3feSDimitry Andric   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 auto operator()(_Args&&... __args) const
325f757f3fSDimitry Andric       noexcept(noexcept(!std::invoke(std::forward<_Args>(__args)...)))
33*cb14a3feSDimitry Andric           -> decltype(!std::invoke(std::forward<_Args>(__args)...)) {
34*cb14a3feSDimitry Andric     return !std::invoke(std::forward<_Args>(__args)...);
35*cb14a3feSDimitry Andric   }
36fe6060f1SDimitry Andric };
37fe6060f1SDimitry Andric 
38349cc55cSDimitry Andric template <class _Fn>
39349cc55cSDimitry Andric struct __not_fn_t : __perfect_forward<__not_fn_op, _Fn> {
40349cc55cSDimitry Andric   using __perfect_forward<__not_fn_op, _Fn>::__perfect_forward;
41349cc55cSDimitry Andric };
42349cc55cSDimitry Andric 
43*cb14a3feSDimitry Andric template <class _Fn,
44*cb14a3feSDimitry Andric           class = enable_if_t< is_constructible_v<decay_t<_Fn>, _Fn> && is_move_constructible_v<decay_t<_Fn>> >>
45*cb14a3feSDimitry Andric _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 auto not_fn(_Fn&& __f) {
465f757f3fSDimitry Andric   return __not_fn_t<decay_t<_Fn>>(std::forward<_Fn>(__f));
47fe6060f1SDimitry Andric }
48fe6060f1SDimitry Andric 
4906c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 17
50fe6060f1SDimitry Andric 
51fe6060f1SDimitry Andric _LIBCPP_END_NAMESPACE_STD
52fe6060f1SDimitry Andric 
53fe6060f1SDimitry Andric #endif // _LIBCPP___FUNCTIONAL_NOT_FN_H
54