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 31 struct __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 40 template <class _Fn> 41 struct __not_fn_t : __perfect_forward<__not_fn_op, _Fn> { 42 using __perfect_forward<__not_fn_op, _Fn>::__perfect_forward; 43 }; 44 45 template <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 55 template <auto _Fn> 56 struct __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 65 template <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