1// <utility> -*- C++ -*-
2
3// Copyright (C) 2001-2014 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
76namespace 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#if __cplusplus > 201103L
156 template <typename _Tp, typename _Up>
157 constexpr _Tp&
158 get(pair<_Tp, _Up>& __p) noexcept
159 { return __p.first; }
160
161 template <typename _Tp, typename _Up>
162 constexpr const _Tp&
163 get(const pair<_Tp, _Up>& __p) noexcept
164 { return __p.first; }
165
166 template <typename _Tp, typename _Up>
167 constexpr _Tp&&
168 get(pair<_Tp, _Up>&& __p) noexcept
169 { return std::move(__p.first); }
170
171 template <typename _Tp, typename _Up>
172 constexpr _Tp&
173 get(pair<_Up, _Tp>& __p) noexcept
174 { return __p.second; }
175
176 template <typename _Tp, typename _Up>
177 constexpr const _Tp&
178 get(const pair<_Up, _Tp>& __p) noexcept
179 { return __p.second; }
180
181 template <typename _Tp, typename _Up>
182 constexpr _Tp&&
183 get(pair<_Up, _Tp>&& __p) noexcept
184 { return std::move(__p.second); }
185
186 /// Assign @p __new_val to @p __obj and return its previous value.
187 template <typename _Tp, typename _Up = _Tp>
188 inline _Tp
189 exchange(_Tp& __obj, _Up&& __new_val)
190 {
191 _Tp __old_val = std::move(__obj);
192 __obj = std::forward<_Up>(__new_val);
193 return __old_val;
194 }
195#endif
196
197 // Stores a tuple of indices. Used by tuple and pair, and by bind() to
198 // extract the elements in a tuple.
199 template<size_t... _Indexes>
200 struct _Index_tuple
201 {
202 typedef _Index_tuple<_Indexes..., sizeof...(_Indexes)> __next;
203 };
204
205 // Builds an _Index_tuple<0, 1, 2, ..., _Num-1>.
206 template<size_t _Num>
207 struct _Build_index_tuple
208 {
209 typedef typename _Build_index_tuple<_Num - 1>::__type::__next __type;
210 };
211
212 template<>
213 struct _Build_index_tuple<0>
214 {
215 typedef _Index_tuple<> __type;
216 };
217
218#if __cplusplus > 201103L
219 /// Class template integer_sequence
220 template<typename _Tp, _Tp... _Idx>
221 struct integer_sequence
222 {
223 typedef _Tp value_type;
224 static constexpr size_t size() { return sizeof...(_Idx); }
225 };
226
227 template<typename _Tp, _Tp _Num,
228 typename _ISeq = typename _Build_index_tuple<_Num>::__type>
229 struct _Make_integer_sequence;
230
231 template<typename _Tp, _Tp _Num, size_t... _Idx>
232 struct _Make_integer_sequence<_Tp, _Num, _Index_tuple<_Idx...>>
233 {
234 static_assert( _Num >= 0,
235 "Cannot make integer sequence of negative length" );
236
237 typedef integer_sequence<_Tp, static_cast<_Tp>(_Idx)...> __type;
238 };
239
240 /// Alias template make_integer_sequence
241 template<typename _Tp, _Tp _Num>
242 using make_integer_sequence
243 = typename _Make_integer_sequence<_Tp, _Num>::__type;
244
245 /// Alias template index_sequence
246 template<size_t... _Idx>
247 using index_sequence = integer_sequence<size_t, _Idx...>;
248
249 /// Alias template make_index_sequence
250 template<size_t _Num>
251 using make_index_sequence = make_integer_sequence<size_t, _Num>;
252
253 /// Alias template index_sequence_for
254 template<typename... _Types>
255 using index_sequence_for = make_index_sequence<sizeof...(_Types)>;
256#endif
257
258_GLIBCXX_END_NAMESPACE_VERSION
259} // namespace
260
261#endif
262
263#endif /* _GLIBCXX_UTILITY */
264