1 | // <utility> -*- C++ -*- |
2 | |
3 | // Copyright (C) 2001-2016 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 <type_traits> |
75 | #include <bits/move.h> |
76 | #include <initializer_list> |
77 | |
78 | namespace std _GLIBCXX_VISIBILITY(default) |
79 | { |
80 | _GLIBCXX_BEGIN_NAMESPACE_VERSION |
81 | |
82 | /// Finds the size of a given tuple type. |
83 | template<typename _Tp> |
84 | struct tuple_size; |
85 | |
86 | // _GLIBCXX_RESOLVE_LIB_DEFECTS |
87 | // 2313. tuple_size should always derive from integral_constant<size_t, N> |
88 | template<typename _Tp> |
89 | struct tuple_size<const _Tp> |
90 | : integral_constant<size_t, tuple_size<_Tp>::value> { }; |
91 | |
92 | template<typename _Tp> |
93 | struct tuple_size<volatile _Tp> |
94 | : integral_constant<size_t, tuple_size<_Tp>::value> { }; |
95 | |
96 | template<typename _Tp> |
97 | struct tuple_size<const volatile _Tp> |
98 | : integral_constant<size_t, tuple_size<_Tp>::value> { }; |
99 | |
100 | /// Gives the type of the ith element of a given tuple type. |
101 | template<std::size_t __i, typename _Tp> |
102 | struct tuple_element; |
103 | |
104 | // Duplicate of C++14's tuple_element_t for internal use in C++11 mode |
105 | template<std::size_t __i, typename _Tp> |
106 | using __tuple_element_t = typename tuple_element<__i, _Tp>::type; |
107 | |
108 | template<std::size_t __i, typename _Tp> |
109 | struct tuple_element<__i, const _Tp> |
110 | { |
111 | typedef typename add_const<__tuple_element_t<__i, _Tp>>::type type; |
112 | }; |
113 | |
114 | template<std::size_t __i, typename _Tp> |
115 | struct tuple_element<__i, volatile _Tp> |
116 | { |
117 | typedef typename add_volatile<__tuple_element_t<__i, _Tp>>::type type; |
118 | }; |
119 | |
120 | template<std::size_t __i, typename _Tp> |
121 | struct tuple_element<__i, const volatile _Tp> |
122 | { |
123 | typedef typename add_cv<__tuple_element_t<__i, _Tp>>::type type; |
124 | }; |
125 | |
126 | #if __cplusplus > 201103L |
127 | #define __cpp_lib_tuple_element_t 201402 |
128 | |
129 | template<std::size_t __i, typename _Tp> |
130 | using tuple_element_t = typename tuple_element<__i, _Tp>::type; |
131 | #endif |
132 | |
133 | template<typename> |
134 | struct __is_tuple_like_impl : false_type |
135 | { }; |
136 | |
137 | // Various functions which give std::pair a tuple-like interface. |
138 | |
139 | /// Partial specialization for std::pair |
140 | template<typename _T1, typename _T2> |
141 | struct __is_tuple_like_impl<std::pair<_T1, _T2>> : true_type |
142 | { }; |
143 | |
144 | /// Partial specialization for std::pair |
145 | template<class _Tp1, class _Tp2> |
146 | struct tuple_size<std::pair<_Tp1, _Tp2>> |
147 | : public integral_constant<std::size_t, 2> { }; |
148 | |
149 | /// Partial specialization for std::pair |
150 | template<class _Tp1, class _Tp2> |
151 | struct tuple_element<0, std::pair<_Tp1, _Tp2>> |
152 | { typedef _Tp1 type; }; |
153 | |
154 | /// Partial specialization for std::pair |
155 | template<class _Tp1, class _Tp2> |
156 | struct tuple_element<1, std::pair<_Tp1, _Tp2>> |
157 | { typedef _Tp2 type; }; |
158 | |
159 | template<std::size_t _Int> |
160 | struct __pair_get; |
161 | |
162 | template<> |
163 | struct __pair_get<0> |
164 | { |
165 | template<typename _Tp1, typename _Tp2> |
166 | static constexpr _Tp1& |
167 | __get(std::pair<_Tp1, _Tp2>& __pair) noexcept |
168 | { return __pair.first; } |
169 | |
170 | template<typename _Tp1, typename _Tp2> |
171 | static constexpr _Tp1&& |
172 | __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept |
173 | { return std::forward<_Tp1>(__pair.first); } |
174 | |
175 | template<typename _Tp1, typename _Tp2> |
176 | static constexpr const _Tp1& |
177 | __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept |
178 | { return __pair.first; } |
179 | }; |
180 | |
181 | template<> |
182 | struct __pair_get<1> |
183 | { |
184 | template<typename _Tp1, typename _Tp2> |
185 | static constexpr _Tp2& |
186 | __get(std::pair<_Tp1, _Tp2>& __pair) noexcept |
187 | { return __pair.second; } |
188 | |
189 | template<typename _Tp1, typename _Tp2> |
190 | static constexpr _Tp2&& |
191 | __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept |
192 | { return std::forward<_Tp2>(__pair.second); } |
193 | |
194 | template<typename _Tp1, typename _Tp2> |
195 | static constexpr const _Tp2& |
196 | __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept |
197 | { return __pair.second; } |
198 | }; |
199 | |
200 | template<std::size_t _Int, class _Tp1, class _Tp2> |
201 | constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type& |
202 | get(std::pair<_Tp1, _Tp2>& __in) noexcept |
203 | { return __pair_get<_Int>::__get(__in); } |
204 | |
205 | template<std::size_t _Int, class _Tp1, class _Tp2> |
206 | constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&& |
207 | get(std::pair<_Tp1, _Tp2>&& __in) noexcept |
208 | { return __pair_get<_Int>::__move_get(std::move(__in)); } |
209 | |
210 | template<std::size_t _Int, class _Tp1, class _Tp2> |
211 | constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type& |
212 | get(const std::pair<_Tp1, _Tp2>& __in) noexcept |
213 | { return __pair_get<_Int>::__const_get(__in); } |
214 | |
215 | #if __cplusplus > 201103L |
216 | |
217 | #define __cpp_lib_tuples_by_type 201304 |
218 | |
219 | template <typename _Tp, typename _Up> |
220 | constexpr _Tp& |
221 | get(pair<_Tp, _Up>& __p) noexcept |
222 | { return __p.first; } |
223 | |
224 | template <typename _Tp, typename _Up> |
225 | constexpr const _Tp& |
226 | get(const pair<_Tp, _Up>& __p) noexcept |
227 | { return __p.first; } |
228 | |
229 | template <typename _Tp, typename _Up> |
230 | constexpr _Tp&& |
231 | get(pair<_Tp, _Up>&& __p) noexcept |
232 | { return std::move(__p.first); } |
233 | |
234 | template <typename _Tp, typename _Up> |
235 | constexpr _Tp& |
236 | get(pair<_Up, _Tp>& __p) noexcept |
237 | { return __p.second; } |
238 | |
239 | template <typename _Tp, typename _Up> |
240 | constexpr const _Tp& |
241 | get(const pair<_Up, _Tp>& __p) noexcept |
242 | { return __p.second; } |
243 | |
244 | template <typename _Tp, typename _Up> |
245 | constexpr _Tp&& |
246 | get(pair<_Up, _Tp>&& __p) noexcept |
247 | { return std::move(__p.second); } |
248 | |
249 | #define __cpp_lib_exchange_function 201304 |
250 | |
251 | /// Assign @p __new_val to @p __obj and return its previous value. |
252 | template <typename _Tp, typename _Up = _Tp> |
253 | inline _Tp |
254 | exchange(_Tp& __obj, _Up&& __new_val) |
255 | { return std::__exchange(__obj, std::forward<_Up>(__new_val)); } |
256 | #endif |
257 | |
258 | // Stores a tuple of indices. Used by tuple and pair, and by bind() to |
259 | // extract the elements in a tuple. |
260 | template<size_t... _Indexes> struct _Index_tuple { }; |
261 | |
262 | // Concatenates two _Index_tuples. |
263 | template<typename _Itup1, typename _Itup2> struct _Itup_cat; |
264 | |
265 | template<size_t... _Ind1, size_t... _Ind2> |
266 | struct _Itup_cat<_Index_tuple<_Ind1...>, _Index_tuple<_Ind2...>> |
267 | { |
268 | using __type = _Index_tuple<_Ind1..., (_Ind2 + sizeof...(_Ind1))...>; |
269 | }; |
270 | |
271 | // Builds an _Index_tuple<0, 1, 2, ..., _Num-1>. |
272 | template<size_t _Num> |
273 | struct _Build_index_tuple |
274 | : _Itup_cat<typename _Build_index_tuple<_Num / 2>::__type, |
275 | typename _Build_index_tuple<_Num - _Num / 2>::__type> |
276 | { }; |
277 | |
278 | template<> |
279 | struct _Build_index_tuple<1> |
280 | { |
281 | typedef _Index_tuple<0> __type; |
282 | }; |
283 | |
284 | template<> |
285 | struct _Build_index_tuple<0> |
286 | { |
287 | typedef _Index_tuple<> __type; |
288 | }; |
289 | |
290 | #if __cplusplus > 201103L |
291 | |
292 | #define __cpp_lib_integer_sequence 201304 |
293 | |
294 | /// Class template integer_sequence |
295 | template<typename _Tp, _Tp... _Idx> |
296 | struct integer_sequence |
297 | { |
298 | typedef _Tp value_type; |
299 | static constexpr size_t size() { return sizeof...(_Idx); } |
300 | }; |
301 | |
302 | template<typename _Tp, _Tp _Num, |
303 | typename _ISeq = typename _Build_index_tuple<_Num>::__type> |
304 | struct _Make_integer_sequence; |
305 | |
306 | template<typename _Tp, _Tp _Num, size_t... _Idx> |
307 | struct _Make_integer_sequence<_Tp, _Num, _Index_tuple<_Idx...>> |
308 | { |
309 | static_assert( _Num >= 0, |
310 | "Cannot make integer sequence of negative length" ); |
311 | |
312 | typedef integer_sequence<_Tp, static_cast<_Tp>(_Idx)...> __type; |
313 | }; |
314 | |
315 | /// Alias template make_integer_sequence |
316 | template<typename _Tp, _Tp _Num> |
317 | using make_integer_sequence |
318 | = typename _Make_integer_sequence<_Tp, _Num>::__type; |
319 | |
320 | /// Alias template index_sequence |
321 | template<size_t... _Idx> |
322 | using index_sequence = integer_sequence<size_t, _Idx...>; |
323 | |
324 | /// Alias template make_index_sequence |
325 | template<size_t _Num> |
326 | using make_index_sequence = make_integer_sequence<size_t, _Num>; |
327 | |
328 | /// Alias template index_sequence_for |
329 | template<typename... _Types> |
330 | using index_sequence_for = make_index_sequence<sizeof...(_Types)>; |
331 | #endif |
332 | |
333 | _GLIBCXX_END_NAMESPACE_VERSION |
334 | } // namespace |
335 | |
336 | #endif |
337 | |
338 | #endif /* _GLIBCXX_UTILITY */ |
339 | |