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
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  template<class _Tp1, class _Tp2>
89    struct tuple_size<std::pair<_Tp1, _Tp2>>
90    : public integral_constant<std::size_t, 2> { };
91
92  template<class _Tp1, class _Tp2>
93    struct tuple_element<0, std::pair<_Tp1, _Tp2>>
94    { typedef _Tp1 type; };
95
96  template<class _Tp1, class _Tp2>
97    struct tuple_element<1, std::pair<_Tp1, _Tp2>>
98    { typedef _Tp2 type; };
99
100  template<std::size_t _Int>
101    struct __pair_get;
102
103  template<>
104    struct __pair_get<0>
105    {
106      template<typename _Tp1, typename _Tp2>
107        static constexpr _Tp1&
108        __get(std::pair<_Tp1, _Tp2>& __pair) noexcept
109        { return __pair.first; }
110
111      template<typename _Tp1, typename _Tp2>
112        static constexpr _Tp1&&
113        __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
114        { return std::forward<_Tp1>(__pair.first); }
115
116      template<typename _Tp1, typename _Tp2>
117        static constexpr const _Tp1&
118        __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
119        { return __pair.first; }
120    };
121
122  template<>
123    struct __pair_get<1>
124    {
125      template<typename _Tp1, typename _Tp2>
126        static constexpr _Tp2&
127        __get(std::pair<_Tp1, _Tp2>& __pair) noexcept
128        { return __pair.second; }
129
130      template<typename _Tp1, typename _Tp2>
131        static constexpr _Tp2&&
132        __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
133        { return std::forward<_Tp2>(__pair.second); }
134
135      template<typename _Tp1, typename _Tp2>
136        static constexpr const _Tp2&
137        __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
138        { return __pair.second; }
139    };
140
141  template<std::size_t _Int, class _Tp1, class _Tp2>
142    constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
143    get(std::pair<_Tp1, _Tp2>& __in) noexcept
144    { return __pair_get<_Int>::__get(__in); }
145
146  template<std::size_t _Int, class _Tp1, class _Tp2>
147    constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&&
148    get(std::pair<_Tp1, _Tp2>&& __in) noexcept
149    { return __pair_get<_Int>::__move_get(std::move(__in)); }
150
151  template<std::size_t _Int, class _Tp1, class _Tp2>
152    constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
153    get(const std::pair<_Tp1, _Tp2>& __in) noexcept
154    { return __pair_get<_Int>::__const_get(__in); }
155
156#if __cplusplus > 201103L
157
158#define __cpp_lib_tuples_by_type 201304
159
160  template <typename _Tp, typename _Up>
161    constexpr _Tp&
162    get(pair<_Tp, _Up>& __p) noexcept
163    { return __p.first; }
164
165  template <typename _Tp, typename _Up>
166    constexpr const _Tp&
167    get(const pair<_Tp, _Up>& __p) noexcept
168    { return __p.first; }
169
170  template <typename _Tp, typename _Up>
171    constexpr _Tp&&
172    get(pair<_Tp, _Up>&& __p) noexcept
173    { return std::move(__p.first); }
174
175  template <typename _Tp, typename _Up>
176    constexpr _Tp&
177    get(pair<_Up, _Tp>& __p) noexcept
178    { return __p.second; }
179
180  template <typename _Tp, typename _Up>
181    constexpr const _Tp&
182    get(const pair<_Up, _Tp>& __p) noexcept
183    { return __p.second; }
184
185  template <typename _Tp, typename _Up>
186    constexpr _Tp&&
187    get(pair<_Up, _Tp>&& __p) noexcept
188    { return std::move(__p.second); }
189
190#define __cpp_lib_exchange_function 201304
191
192  /// Assign @p __new_val to @p __obj and return its previous value.
193  template <typename _Tp, typename _Up = _Tp>
194    inline _Tp
195    exchange(_Tp& __obj, _Up&& __new_val)
196    {
197      _Tp __old_val = std::move(__obj);
198      __obj = std::forward<_Up>(__new_val);
199      return __old_val;
200    }
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