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 #include <__type_traits/is_same.h>
15 #include <__type_traits/remove_cv.h>
16 
17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18 #  pragma GCC system_header
19 #endif
20 
21 _LIBCPP_BEGIN_NAMESPACE_STD
22 
23 #if __has_builtin(__is_void)
24 
25 template <class _Tp>
26 struct _LIBCPP_TEMPLATE_VIS is_void : _BoolConstant<__is_void(_Tp)> { };
27 
28 #if _LIBCPP_STD_VER > 14
29 template <class _Tp>
30 inline constexpr bool is_void_v = __is_void(_Tp);
31 #endif
32 
33 #else
34 
35 template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_void
36     : public is_same<__remove_cv_t<_Tp>, void> {};
37 
38 #if _LIBCPP_STD_VER > 14
39 template <class _Tp>
40 inline constexpr bool is_void_v = is_void<_Tp>::value;
41 #endif
42 
43 #endif // __has_builtin(__is_void)
44 
45 _LIBCPP_END_NAMESPACE_STD
46 
47 #endif // _LIBCPP___TYPE_TRAITS_IS_VOID_H
48