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   using type = __copy_cv_t<_From, _To>;
26 };
27 
28 template <class _From, class _To>
29 struct __copy_cvref<_From&, _To> {
30   using type = __add_lvalue_reference_t<__copy_cv_t<_From, _To> >;
31 };
32 
33 template <class _From, class _To>
34 struct __copy_cvref<_From&&, _To> {
35   using type = __add_rvalue_reference_t<__copy_cv_t<_From, _To> >;
36 };
37 
38 template <class _From, class _To>
39 using __copy_cvref_t = typename __copy_cvref<_From, _To>::type;
40 
41 _LIBCPP_END_NAMESPACE_STD
42 
43 #endif // _LIBCPP___TYPE_TRAITS_COPY_CVREF_H
44