1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP___FUNCTIONAL_NOT_FN_H
11#define _LIBCPP___FUNCTIONAL_NOT_FN_H
12
13#include <__config>
14#include <__functional/invoke.h>
15#include <__functional/perfect_forward.h>
16#include <__type_traits/decay.h>
17#include <__type_traits/enable_if.h>
18#include <__type_traits/is_constructible.h>
19#include <__type_traits/is_member_pointer.h>
20#include <__type_traits/is_pointer.h>
21#include <__utility/forward.h>
22
23#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
24# pragma GCC system_header
25#endif
26
27_LIBCPP_BEGIN_NAMESPACE_STD
28
29#if _LIBCPP_STD_VER >= 17
30
31struct __not_fn_op {
32 template <class... _Args>
33 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 auto operator()(_Args&&... __args) const
34 noexcept(noexcept(!std::invoke(std::forward<_Args>(__args)...)))
35 -> decltype(!std::invoke(std::forward<_Args>(__args)...)) {
36 return !std::invoke(std::forward<_Args>(__args)...);
37 }
38};
39
40template <class _Fn>
41struct __not_fn_t : __perfect_forward<__not_fn_op, _Fn> {
42 using __perfect_forward<__not_fn_op, _Fn>::__perfect_forward;
43};
44
45template <class _Fn,
46 class = enable_if_t< is_constructible_v<decay_t<_Fn>, _Fn> && is_move_constructible_v<decay_t<_Fn>> >>
47_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 auto not_fn(_Fn&& __f) {
48 return __not_fn_t<decay_t<_Fn>>(std::forward<_Fn>(__f));
49}
50
51#endif // _LIBCPP_STD_VER >= 17
52
53#if _LIBCPP_STD_VER >= 26
54
55template <auto _Fn>
56struct __nttp_not_fn_t {
57 template <class... _Args>
58 [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Args&&... __args) const
59 noexcept(noexcept(!std::invoke(_Fn, std::forward<_Args>(__args)...)))
60 -> decltype(!std::invoke(_Fn, std::forward<_Args>(__args)...)) {
61 return !std::invoke(_Fn, std::forward<_Args>(__args)...);
62 }
63};
64
65template <auto _Fn>
66[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI constexpr auto not_fn() noexcept {
67 if constexpr (using _Ty = decltype(_Fn); is_pointer_v<_Ty> || is_member_pointer_v<_Ty>)
68 static_assert(_Fn != nullptr, "f cannot be equal to nullptr");
69 return __nttp_not_fn_t<_Fn>();
70}
71
72#endif // _LIBCPP_STD_VER >= 26
73
74_LIBCPP_END_NAMESPACE_STD
75
76#endif // _LIBCPP___FUNCTIONAL_NOT_FN_H
77