libstdc++
tr2/type_traits
Go to the documentation of this file.
1 // TR2 <type_traits> -*- C++ -*-
2 
3 // Copyright (C) 2011-2021 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /** @file tr2/type_traits
26  * This is a TR2 C++ Library header.
27  */
28 
29 #ifndef _GLIBCXX_TR2_TYPE_TRAITS
30 #define _GLIBCXX_TR2_TYPE_TRAITS 1
31 
32 #pragma GCC system_header
33 #include <type_traits>
34 #include <bits/c++config.h>
35 
36 namespace std _GLIBCXX_VISIBILITY(default)
37 {
38 _GLIBCXX_BEGIN_NAMESPACE_VERSION
39 
40 namespace tr2
41 {
42  /**
43  * @addtogroup metaprogramming
44  * @{
45  */
46 
47  /**
48  * See N2965: Type traits and base classes
49  * by Michael Spertus
50  */
51 
52  /**
53  * Simple typelist. Compile-time list of types.
54  */
55  template<typename... _Elements>
57 
58  /// Specialization for an empty typelist.
59  template<>
61  {
62  typedef std::true_type empty;
63  };
64 
65  /// Partial specialization.
66  template<typename _First, typename... _Rest>
67  struct __reflection_typelist<_First, _Rest...>
68  {
69  typedef std::false_type empty;
70 
71  struct first
72  {
73  typedef _First type;
74  };
75 
76  struct rest
77  {
78  typedef __reflection_typelist<_Rest...> type;
79  };
80  };
81 
82  /// Sequence abstraction metafunctions for manipulating a typelist.
83 
84 
85 
86  /// Enumerate all the base classes of a class. Form of a typelist.
87  template<typename _Tp>
88  struct bases
89  {
90  typedef __reflection_typelist<__bases(_Tp)...> type;
91  };
92 
93  /// Enumerate all the direct base classes of a class. Form of a typelist.
94  template<typename _Tp>
95  struct direct_bases
96  {
97  typedef __reflection_typelist<__direct_bases(_Tp)...> type;
98  };
99 
100  /// @} group metaprogramming
101 }
102 
103 _GLIBCXX_END_NAMESPACE_VERSION
104 }
105 
106 #endif // _GLIBCXX_TR2_TYPE_TRAITS
ISO C++ entities toplevel namespace is std.
constexpr auto empty(const _Container &__cont) noexcept(noexcept(__cont.empty())) -> decltype(__cont.empty())
Return whether a container is empty.
Definition: range_access.h:263
integral_constant
Definition: type_traits:66
Sequence abstraction metafunctions for manipulating a typelist.
Definition: tr2/type_traits:89
Enumerate all the direct base classes of a class. Form of a typelist.
Definition: tr2/type_traits:96