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
77namespace 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 */
273