libstdc++
utility
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1 // <utility> -*- C++ -*-
2 
3 // Copyright (C) 2001-2015 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 
74 #include <bits/move.h>
75 #include <initializer_list>
76 
77 namespace std _GLIBCXX_VISIBILITY(default)
78 {
79 _GLIBCXX_BEGIN_NAMESPACE_VERSION
80 
81  template<class _Tp>
82  class tuple_size;
83 
84  template<std::size_t _Int, class _Tp>
85  class tuple_element;
86 
87  // Various functions which give std::pair a tuple-like interface.
88 
89  /// Partial specialization for std::pair
90  template<class _Tp1, class _Tp2>
91  struct tuple_size<std::pair<_Tp1, _Tp2>>
92  : public integral_constant<std::size_t, 2> { };
93 
94  /// Partial specialization for std::pair
95  template<class _Tp1, class _Tp2>
96  struct tuple_element<0, std::pair<_Tp1, _Tp2>>
97  { typedef _Tp1 type; };
98 
99  /// Partial specialization for std::pair
100  template<class _Tp1, class _Tp2>
101  struct tuple_element<1, std::pair<_Tp1, _Tp2>>
102  { typedef _Tp2 type; };
103 
104  template<std::size_t _Int>
105  struct __pair_get;
106 
107  template<>
108  struct __pair_get<0>
109  {
110  template<typename _Tp1, typename _Tp2>
111  static constexpr _Tp1&
112  __get(std::pair<_Tp1, _Tp2>& __pair) noexcept
113  { return __pair.first; }
114 
115  template<typename _Tp1, typename _Tp2>
116  static constexpr _Tp1&&
117  __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
118  { return std::forward<_Tp1>(__pair.first); }
119 
120  template<typename _Tp1, typename _Tp2>
121  static constexpr const _Tp1&
122  __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
123  { return __pair.first; }
124  };
125 
126  template<>
127  struct __pair_get<1>
128  {
129  template<typename _Tp1, typename _Tp2>
130  static constexpr _Tp2&
131  __get(std::pair<_Tp1, _Tp2>& __pair) noexcept
132  { return __pair.second; }
133 
134  template<typename _Tp1, typename _Tp2>
135  static constexpr _Tp2&&
136  __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
137  { return std::forward<_Tp2>(__pair.second); }
138 
139  template<typename _Tp1, typename _Tp2>
140  static constexpr const _Tp2&
141  __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
142  { return __pair.second; }
143  };
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>::__get(__in); }
149 
150  template<std::size_t _Int, class _Tp1, class _Tp2>
151  constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&&
152  get(std::pair<_Tp1, _Tp2>&& __in) noexcept
153  { return __pair_get<_Int>::__move_get(std::move(__in)); }
154 
155  template<std::size_t _Int, class _Tp1, class _Tp2>
156  constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
157  get(const std::pair<_Tp1, _Tp2>& __in) noexcept
158  { return __pair_get<_Int>::__const_get(__in); }
159 
160 #if __cplusplus > 201103L
161 
162 #define __cpp_lib_tuples_by_type 201304
163 
164  template <typename _Tp, typename _Up>
165  constexpr _Tp&
166  get(pair<_Tp, _Up>& __p) noexcept
167  { return __p.first; }
168 
169  template <typename _Tp, typename _Up>
170  constexpr const _Tp&
171  get(const pair<_Tp, _Up>& __p) noexcept
172  { return __p.first; }
173 
174  template <typename _Tp, typename _Up>
175  constexpr _Tp&&
176  get(pair<_Tp, _Up>&& __p) noexcept
177  { return std::move(__p.first); }
178 
179  template <typename _Tp, typename _Up>
180  constexpr _Tp&
181  get(pair<_Up, _Tp>& __p) noexcept
182  { return __p.second; }
183 
184  template <typename _Tp, typename _Up>
185  constexpr const _Tp&
186  get(const pair<_Up, _Tp>& __p) noexcept
187  { return __p.second; }
188 
189  template <typename _Tp, typename _Up>
190  constexpr _Tp&&
191  get(pair<_Up, _Tp>&& __p) noexcept
192  { return std::move(__p.second); }
193 
194 #define __cpp_lib_exchange_function 201304
195 
196  /// Assign @p __new_val to @p __obj and return its previous value.
197  template <typename _Tp, typename _Up = _Tp>
198  inline _Tp
199  exchange(_Tp& __obj, _Up&& __new_val)
200  { return std::__exchange(__obj, std::forward<_Up>(__new_val)); }
201 #endif
202 
203  // Stores a tuple of indices. Used by tuple and pair, and by bind() to
204  // extract the elements in a tuple.
205  template<size_t... _Indexes>
206  struct _Index_tuple
207  {
208  typedef _Index_tuple<_Indexes..., sizeof...(_Indexes)> __next;
209  };
210 
211  // Builds an _Index_tuple<0, 1, 2, ..., _Num-1>.
212  template<size_t _Num>
213  struct _Build_index_tuple
214  {
215  typedef typename _Build_index_tuple<_Num - 1>::__type::__next __type;
216  };
217 
218  template<>
219  struct _Build_index_tuple<0>
220  {
221  typedef _Index_tuple<> __type;
222  };
223 
224 #if __cplusplus > 201103L
225 
226 #define __cpp_lib_integer_sequence 201304
227 
228  /// Class template integer_sequence
229  template<typename _Tp, _Tp... _Idx>
230  struct integer_sequence
231  {
232  typedef _Tp value_type;
233  static constexpr size_t size() { return sizeof...(_Idx); }
234  };
235 
236  template<typename _Tp, _Tp _Num,
237  typename _ISeq = typename _Build_index_tuple<_Num>::__type>
238  struct _Make_integer_sequence;
239 
240  template<typename _Tp, _Tp _Num, size_t... _Idx>
241  struct _Make_integer_sequence<_Tp, _Num, _Index_tuple<_Idx...>>
242  {
243  static_assert( _Num >= 0,
244  "Cannot make integer sequence of negative length" );
245 
246  typedef integer_sequence<_Tp, static_cast<_Tp>(_Idx)...> __type;
247  };
248 
249  /// Alias template make_integer_sequence
250  template<typename _Tp, _Tp _Num>
251  using make_integer_sequence
252  = typename _Make_integer_sequence<_Tp, _Num>::__type;
253 
254  /// Alias template index_sequence
255  template<size_t... _Idx>
256  using index_sequence = integer_sequence<size_t, _Idx...>;
257 
258  /// Alias template make_index_sequence
259  template<size_t _Num>
260  using make_index_sequence = make_integer_sequence<size_t, _Num>;
261 
262  /// Alias template index_sequence_for
263  template<typename... _Types>
264  using index_sequence_for = make_index_sequence<sizeof...(_Types)>;
265 #endif
266 
267 _GLIBCXX_END_NAMESPACE_VERSION
268 } // namespace
269 
270 #endif
271 
272 #endif /* _GLIBCXX_UTILITY */