1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef _LIBCPP___TYPE_TRAITS_NEGATION_H
10 #define _LIBCPP___TYPE_TRAITS_NEGATION_H
11 
12 #include <__config>
13 #include <__type_traits/integral_constant.h>
14 
15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
16 #  pragma GCC system_header
17 #endif
18 
19 _LIBCPP_BEGIN_NAMESPACE_STD
20 
21 template <class _Pred>
22 struct _Not : _BoolConstant<!_Pred::value> {};
23 
24 #if _LIBCPP_STD_VER > 14
25 template <class _Tp>
26 struct negation : _Not<_Tp> {};
27 template<class _Tp>
28 inline constexpr bool negation_v = !_Tp::value;
29 #endif // _LIBCPP_STD_VER > 14
30 
31 _LIBCPP_END_NAMESPACE_STD
32 
33 #endif // _LIBCPP___TYPE_TRAITS_NEGATION_H
34