libstdc++
utility
1 // <utility> -*- C++ -*-
2 
3 // Copyright (C) 2001-2013 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 /*
26  *
27  * Copyright (c) 1994
28  * Hewlett-Packard Company
29  *
30  * Permission to use, copy, modify, distribute and sell this software
31  * and its documentation for any purpose is hereby granted without fee,
32  * provided that the above copyright notice appear in all copies and
33  * that both that copyright notice and this permission notice appear
34  * in supporting documentation. Hewlett-Packard Company makes no
35  * representations about the suitability of this software for any
36  * purpose. It is provided "as is" without express or implied warranty.
37  *
38  *
39  * Copyright (c) 1996,1997
40  * Silicon Graphics Computer Systems, Inc.
41  *
42  * Permission to use, copy, modify, distribute and sell this software
43  * and its documentation for any purpose is hereby granted without fee,
44  * provided that the above copyright notice appear in all copies and
45  * that both that copyright notice and this permission notice appear
46  * in supporting documentation. Silicon Graphics makes no
47  * representations about the suitability of this software for any
48  * purpose. It is provided "as is" without express or implied warranty.
49  */
50 
51 /** @file include/utility
52  * This is a Standard C++ Library header.
53  */
54 
55 #ifndef _GLIBCXX_UTILITY
56 #define _GLIBCXX_UTILITY 1
57 
58 #pragma GCC system_header
59 
60 /**
61  * @defgroup utilities Utilities
62  *
63  * Components deemed generally useful. Includes pair, tuple,
64  * forward/move helpers, ratio, function object, metaprogramming and
65  * type traits, time, date, and memory functions.
66  */
67 
68 #include <bits/c++config.h>
69 #include <bits/stl_relops.h>
70 #include <bits/stl_pair.h>
71 
72 #if __cplusplus >= 201103L
73 #include <bits/move.h>
74 #include <initializer_list>
75 
76 namespace std _GLIBCXX_VISIBILITY(default)
77 {
78 _GLIBCXX_BEGIN_NAMESPACE_VERSION
79 
80  template<class _Tp>
81  class tuple_size;
82 
83  template<std::size_t _Int, class _Tp>
84  class tuple_element;
85 
86  // Various functions which give std::pair a tuple-like interface.
87  template<class _Tp1, class _Tp2>
88  struct tuple_size<std::pair<_Tp1, _Tp2>>
89  : public integral_constant<std::size_t, 2> { };
90 
91  template<class _Tp1, class _Tp2>
92  struct tuple_element<0, std::pair<_Tp1, _Tp2>>
93  { typedef _Tp1 type; };
94 
95  template<class _Tp1, class _Tp2>
96  struct tuple_element<1, std::pair<_Tp1, _Tp2>>
97  { typedef _Tp2 type; };
98 
99  template<std::size_t _Int>
100  struct __pair_get;
101 
102  template<>
103  struct __pair_get<0>
104  {
105  template<typename _Tp1, typename _Tp2>
106  static constexpr _Tp1&
107  __get(std::pair<_Tp1, _Tp2>& __pair) noexcept
108  { return __pair.first; }
109 
110  template<typename _Tp1, typename _Tp2>
111  static constexpr _Tp1&&
112  __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
113  { return std::forward<_Tp1>(__pair.first); }
114 
115  template<typename _Tp1, typename _Tp2>
116  static constexpr const _Tp1&
117  __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
118  { return __pair.first; }
119  };
120 
121  template<>
122  struct __pair_get<1>
123  {
124  template<typename _Tp1, typename _Tp2>
125  static constexpr _Tp2&
126  __get(std::pair<_Tp1, _Tp2>& __pair) noexcept
127  { return __pair.second; }
128 
129  template<typename _Tp1, typename _Tp2>
130  static constexpr _Tp2&&
131  __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
132  { return std::forward<_Tp2>(__pair.second); }
133 
134  template<typename _Tp1, typename _Tp2>
135  static constexpr const _Tp2&
136  __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
137  { return __pair.second; }
138  };
139 
140  template<std::size_t _Int, class _Tp1, class _Tp2>
141  constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
142  get(std::pair<_Tp1, _Tp2>& __in) noexcept
143  { return __pair_get<_Int>::__get(__in); }
144 
145  template<std::size_t _Int, class _Tp1, class _Tp2>
146  constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&&
147  get(std::pair<_Tp1, _Tp2>&& __in) noexcept
148  { return __pair_get<_Int>::__move_get(std::move(__in)); }
149 
150  template<std::size_t _Int, class _Tp1, class _Tp2>
151  constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
152  get(const std::pair<_Tp1, _Tp2>& __in) noexcept
153  { return __pair_get<_Int>::__const_get(__in); }
154 
155 _GLIBCXX_END_NAMESPACE_VERSION
156 } // namespace
157 
158 #endif
159 
160 #endif /* _GLIBCXX_UTILITY */