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_IS_VOID_H
10 #define _LIBCPP___TYPE_TRAITS_IS_VOID_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 #if __has_builtin(__is_void)
22 
23 template <class _Tp>
24 struct _LIBCPP_TEMPLATE_VIS is_void : _BoolConstant<__is_void(_Tp)> { };
25 
26 #if _LIBCPP_STD_VER > 14
27 template <class _Tp>
28 inline constexpr bool is_void_v = __is_void(_Tp);
29 #endif
30 
31 #else
32 
33 template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_void
34     : public is_same<typename remove_cv<_Tp>::type, void> {};
35 
36 #if _LIBCPP_STD_VER > 14
37 template <class _Tp>
38 inline constexpr bool is_void_v = is_void<_Tp>::value;
39 #endif
40 
41 #endif // __has_builtin(__is_void)
42 
43 _LIBCPP_END_NAMESPACE_STD
44 
45 #endif // _LIBCPP___TYPE_TRAITS_IS_VOID_H
46