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_APPLY_CV_H
10 #define _LIBCPP___TYPE_TRAITS_APPLY_CV_H
11 
12 #include <__config>
13 #include <__type_traits/is_const.h>
14 #include <__type_traits/is_volatile.h>
15 #include <__type_traits/remove_reference.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 _Tp,
24           bool = is_const<__libcpp_remove_reference_t<_Tp> >::value,
25           bool = is_volatile<__libcpp_remove_reference_t<_Tp> >::value>
26 struct __apply_cv_impl {
27   template <class _Up>
28   using __apply _LIBCPP_NODEBUG = _Up;
29 };
30 
31 template <class _Tp>
32 struct __apply_cv_impl<_Tp, true, false> {
33   template <class _Up>
34   using __apply _LIBCPP_NODEBUG = const _Up;
35 };
36 
37 template <class _Tp>
38 struct __apply_cv_impl<_Tp, false, true> {
39   template <class _Up>
40   using __apply _LIBCPP_NODEBUG = volatile _Up;
41 };
42 
43 template <class _Tp>
44 struct __apply_cv_impl<_Tp, true, true> {
45   template <class _Up>
46   using __apply _LIBCPP_NODEBUG = const volatile _Up;
47 };
48 
49 template <class _Tp>
50 struct __apply_cv_impl<_Tp&, false, false> {
51   template <class _Up>
52   using __apply _LIBCPP_NODEBUG = _Up&;
53 };
54 
55 template <class _Tp>
56 struct __apply_cv_impl<_Tp&, true, false> {
57   template <class _Up>
58   using __apply _LIBCPP_NODEBUG = const _Up&;
59 };
60 
61 template <class _Tp>
62 struct __apply_cv_impl<_Tp&, false, true> {
63   template <class _Up>
64   using __apply _LIBCPP_NODEBUG = volatile _Up&;
65 };
66 
67 template <class _Tp>
68 struct __apply_cv_impl<_Tp&, true, true> {
69   template <class _Up>
70   using __apply _LIBCPP_NODEBUG = const volatile _Up&;
71 };
72 
73 template <class _Tp, class _Up>
74 using __apply_cv_t _LIBCPP_NODEBUG = typename __apply_cv_impl<_Tp>::template __apply<_Up>;
75 
76 _LIBCPP_END_NAMESPACE_STD
77 
78 #endif // _LIBCPP___TYPE_TRAITS_APPLY_CV_H
79