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_TYPE_IDENTITY_H
10 #define _LIBCPP___TYPE_TRAITS_TYPE_IDENTITY_H
11 
12 #include <__config>
13 
14 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
15 #  pragma GCC system_header
16 #endif
17 
18 _LIBCPP_BEGIN_NAMESPACE_STD
19 
20 template <class _Tp>
21 struct __type_identity {
22   typedef _Tp type;
23 };
24 
25 template <class _Tp>
26 using __type_identity_t _LIBCPP_NODEBUG = typename __type_identity<_Tp>::type;
27 
28 #if _LIBCPP_STD_VER >= 20
29 template <class _Tp>
30 struct type_identity {
31   typedef _Tp type;
32 };
33 template <class _Tp>
34 using type_identity_t = typename type_identity<_Tp>::type;
35 #endif
36 
37 _LIBCPP_END_NAMESPACE_STD
38 
39 #endif // _LIBCPP___TYPE_TRAITS_TYPE_IDENTITY_H
40