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