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 <__utility/forward.h> 17 #include <type_traits> 18 19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 20 # pragma GCC system_header 21 #endif 22 23 _LIBCPP_BEGIN_NAMESPACE_STD 24 25 #if _LIBCPP_STD_VER > 14 26 27 struct __not_fn_op { 28 template <class... _Args> 29 _LIBCPP_HIDE_FROM_ABI 30 _LIBCPP_CONSTEXPR_SINCE_CXX20 auto operator()(_Args&&... __args) const 31 noexcept(noexcept(!_VSTD::invoke(_VSTD::forward<_Args>(__args)...))) 32 -> decltype( !_VSTD::invoke(_VSTD::forward<_Args>(__args)...)) 33 { return !_VSTD::invoke(_VSTD::forward<_Args>(__args)...); } 34 }; 35 36 template <class _Fn> 37 struct __not_fn_t : __perfect_forward<__not_fn_op, _Fn> { 38 using __perfect_forward<__not_fn_op, _Fn>::__perfect_forward; 39 }; 40 41 template <class _Fn, class = enable_if_t< 42 is_constructible_v<decay_t<_Fn>, _Fn> && 43 is_move_constructible_v<decay_t<_Fn>> 44 >> 45 _LIBCPP_HIDE_FROM_ABI 46 _LIBCPP_CONSTEXPR_SINCE_CXX20 auto not_fn(_Fn&& __f) { 47 return __not_fn_t<decay_t<_Fn>>(_VSTD::forward<_Fn>(__f)); 48 } 49 50 #endif // _LIBCPP_STD_VER > 14 51 52 _LIBCPP_END_NAMESPACE_STD 53 54 #endif // _LIBCPP___FUNCTIONAL_NOT_FN_H 55