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_move_constructible.h> 20 #include <__utility/forward.h> 21 22 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 23 # pragma GCC system_header 24 #endif 25 26 _LIBCPP_BEGIN_NAMESPACE_STD 27 28 #if _LIBCPP_STD_VER >= 17 29 30 struct __not_fn_op { 31 template <class... _Args> 32 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 auto operator()(_Args&&... __args) const 33 noexcept(noexcept(!std::invoke(std::forward<_Args>(__args)...))) 34 -> decltype(!std::invoke(std::forward<_Args>(__args)...)) { 35 return !std::invoke(std::forward<_Args>(__args)...); 36 } 37 }; 38 39 template <class _Fn> 40 struct __not_fn_t : __perfect_forward<__not_fn_op, _Fn> { 41 using __perfect_forward<__not_fn_op, _Fn>::__perfect_forward; 42 }; 43 44 template <class _Fn, 45 class = enable_if_t< is_constructible_v<decay_t<_Fn>, _Fn> && is_move_constructible_v<decay_t<_Fn>> >> 46 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 auto not_fn(_Fn&& __f) { 47 return __not_fn_t<decay_t<_Fn>>(std::forward<_Fn>(__f)); 48 } 49 50 #endif // _LIBCPP_STD_VER >= 17 51 52 _LIBCPP_END_NAMESPACE_STD 53 54 #endif // _LIBCPP___FUNCTIONAL_NOT_FN_H 55