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_COPY_CVREF_H
10 #define _LIBCPP___TYPE_TRAITS_COPY_CVREF_H
11 
12 #include <__config>
13 #include <__type_traits/add_lvalue_reference.h>
14 #include <__type_traits/add_rvalue_reference.h>
15 #include <__type_traits/copy_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 template <class _From, class _To>
24 struct __copy_cvref
25 {
26     using type = __copy_cv_t<_From, _To>;
27 };
28 
29 template <class _From, class _To>
30 struct __copy_cvref<_From&, _To>
31 {
32     using type = __add_lvalue_reference_t<__copy_cv_t<_From, _To> >;
33 };
34 
35 template <class _From, class _To>
36 struct __copy_cvref<_From&&, _To>
37 {
38     using type = __add_rvalue_reference_t<__copy_cv_t<_From, _To> >;
39 };
40 
41 template <class _From, class _To>
42 using __copy_cvref_t = typename __copy_cvref<_From, _To>::type;
43 
44 _LIBCPP_END_NAMESPACE_STD
45 
46 #endif // _LIBCPP___TYPE_TRAITS_COPY_CVREF_H
47