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> struct _Index_tuple { };
206
207  // Concatenates two _Index_tuples.
208  template<typename _Itup1, typename _Itup2> struct _Itup_cat;
209
210  template<size_t... _Ind1, size_t... _Ind2>
211    struct _Itup_cat<_Index_tuple<_Ind1...>, _Index_tuple<_Ind2...>>
212    {
213      using __type = _Index_tuple<_Ind1..., (_Ind2 + sizeof...(_Ind1))...>;
214    };
215
216  // Builds an _Index_tuple<0, 1, 2, ..., _Num-1>.
217  template<size_t _Num>
218    struct _Build_index_tuple
219    : _Itup_cat<typename _Build_index_tuple<_Num / 2>::__type,
220		typename _Build_index_tuple<_Num - _Num / 2>::__type>
221    { };
222
223  template<>
224    struct _Build_index_tuple<1>
225    {
226      typedef _Index_tuple<0> __type;
227    };
228
229  template<>
230    struct _Build_index_tuple<0>
231    {
232      typedef _Index_tuple<> __type;
233    };
234
235#if __cplusplus > 201103L
236
237#define __cpp_lib_integer_sequence 201304
238
239  /// Class template integer_sequence
240  template<typename _Tp, _Tp... _Idx>
241    struct integer_sequence
242    {
243      typedef _Tp value_type;
244      static constexpr size_t size() { return sizeof...(_Idx); }
245    };
246
247  template<typename _Tp, _Tp _Num,
248	   typename _ISeq = typename _Build_index_tuple<_Num>::__type>
249    struct _Make_integer_sequence;
250
251  template<typename _Tp, _Tp _Num,  size_t... _Idx>
252    struct _Make_integer_sequence<_Tp, _Num, _Index_tuple<_Idx...>>
253    {
254      static_assert( _Num >= 0,
255		     "Cannot make integer sequence of negative length" );
256
257      typedef integer_sequence<_Tp, static_cast<_Tp>(_Idx)...> __type;
258    };
259
260  /// Alias template make_integer_sequence
261  template<typename _Tp, _Tp _Num>
262    using make_integer_sequence
263      = typename _Make_integer_sequence<_Tp, _Num>::__type;
264
265  /// Alias template index_sequence
266  template<size_t... _Idx>
267    using index_sequence = integer_sequence<size_t, _Idx...>;
268
269  /// Alias template make_index_sequence
270  template<size_t _Num>
271    using make_index_sequence = make_integer_sequence<size_t, _Num>;
272
273  /// Alias template index_sequence_for
274  template<typename... _Types>
275    using index_sequence_for = make_index_sequence<sizeof...(_Types)>;
276#endif
277
278_GLIBCXX_END_NAMESPACE_VERSION
279} // namespace
280
281#endif
282
283#endif /* _GLIBCXX_UTILITY */
284