Line data Source code
1 : // <utility> -*- C++ -*-
2 :
3 : // Copyright (C) 2001-2018 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 : // 2770. tuple_size<const T> specialization is not SFINAE compatible
89 :
90 : template<typename _Tp,
91 : typename _Up = typename remove_cv<_Tp>::type,
92 : typename = typename enable_if<is_same<_Tp, _Up>::value>::type,
93 : size_t = tuple_size<_Tp>::value>
94 : using __enable_if_has_tuple_size = _Tp;
95 :
96 : template<typename _Tp>
97 : struct tuple_size<const __enable_if_has_tuple_size<_Tp>>
98 : : public tuple_size<_Tp> { };
99 :
100 : template<typename _Tp>
101 : struct tuple_size<volatile __enable_if_has_tuple_size<_Tp>>
102 : : public tuple_size<_Tp> { };
103 :
104 : template<typename _Tp>
105 : struct tuple_size<const volatile __enable_if_has_tuple_size<_Tp>>
106 : : public tuple_size<_Tp> { };
107 :
108 : /// Gives the type of the ith element of a given tuple type.
109 : template<std::size_t __i, typename _Tp>
110 : struct tuple_element;
111 :
112 : // Duplicate of C++14's tuple_element_t for internal use in C++11 mode
113 : template<std::size_t __i, typename _Tp>
114 : using __tuple_element_t = typename tuple_element<__i, _Tp>::type;
115 :
116 : template<std::size_t __i, typename _Tp>
117 : struct tuple_element<__i, const _Tp>
118 : {
119 : typedef typename add_const<__tuple_element_t<__i, _Tp>>::type type;
120 : };
121 :
122 : template<std::size_t __i, typename _Tp>
123 : struct tuple_element<__i, volatile _Tp>
124 : {
125 : typedef typename add_volatile<__tuple_element_t<__i, _Tp>>::type type;
126 : };
127 :
128 : template<std::size_t __i, typename _Tp>
129 : struct tuple_element<__i, const volatile _Tp>
130 : {
131 : typedef typename add_cv<__tuple_element_t<__i, _Tp>>::type type;
132 : };
133 :
134 : #if __cplusplus > 201103L
135 : #define __cpp_lib_tuple_element_t 201402
136 :
137 : template<std::size_t __i, typename _Tp>
138 : using tuple_element_t = typename tuple_element<__i, _Tp>::type;
139 : #endif
140 :
141 : // Various functions which give std::pair a tuple-like interface.
142 :
143 : /// Partial specialization for std::pair
144 : template<typename _T1, typename _T2>
145 : struct __is_tuple_like_impl<std::pair<_T1, _T2>> : true_type
146 : { };
147 :
148 : /// Partial specialization for std::pair
149 : template<class _Tp1, class _Tp2>
150 : struct tuple_size<std::pair<_Tp1, _Tp2>>
151 : : public integral_constant<std::size_t, 2> { };
152 :
153 : /// Partial specialization for std::pair
154 : template<class _Tp1, class _Tp2>
155 : struct tuple_element<0, std::pair<_Tp1, _Tp2>>
156 : { typedef _Tp1 type; };
157 :
158 : /// Partial specialization for std::pair
159 : template<class _Tp1, class _Tp2>
160 : struct tuple_element<1, std::pair<_Tp1, _Tp2>>
161 : { typedef _Tp2 type; };
162 :
163 : template<std::size_t _Int>
164 : struct __pair_get;
165 :
166 : template<>
167 : struct __pair_get<0>
168 : {
169 : template<typename _Tp1, typename _Tp2>
170 : static constexpr _Tp1&
171 24239 : __get(std::pair<_Tp1, _Tp2>& __pair) noexcept
172 24239 : { return __pair.first; }
173 :
174 : template<typename _Tp1, typename _Tp2>
175 : static constexpr _Tp1&&
176 : __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
177 : { return std::forward<_Tp1>(__pair.first); }
178 :
179 : template<typename _Tp1, typename _Tp2>
180 : static constexpr const _Tp1&
181 6602 : __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
182 6602 : { return __pair.first; }
183 :
184 : template<typename _Tp1, typename _Tp2>
185 : static constexpr const _Tp1&&
186 : __const_move_get(const std::pair<_Tp1, _Tp2>&& __pair) noexcept
187 : { return std::forward<const _Tp1>(__pair.first); }
188 : };
189 :
190 : template<>
191 : struct __pair_get<1>
192 : {
193 : template<typename _Tp1, typename _Tp2>
194 : static constexpr _Tp2&
195 : __get(std::pair<_Tp1, _Tp2>& __pair) noexcept
196 : { return __pair.second; }
197 :
198 : template<typename _Tp1, typename _Tp2>
199 : static constexpr _Tp2&&
200 : __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
201 : { return std::forward<_Tp2>(__pair.second); }
202 :
203 : template<typename _Tp1, typename _Tp2>
204 : static constexpr const _Tp2&
205 : __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
206 : { return __pair.second; }
207 :
208 : template<typename _Tp1, typename _Tp2>
209 : static constexpr const _Tp2&&
210 : __const_move_get(const std::pair<_Tp1, _Tp2>&& __pair) noexcept
211 : { return std::forward<const _Tp2>(__pair.second); }
212 : };
213 :
214 : template<std::size_t _Int, class _Tp1, class _Tp2>
215 : constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
216 24239 : get(std::pair<_Tp1, _Tp2>& __in) noexcept
217 24239 : { return __pair_get<_Int>::__get(__in); }
218 :
219 : template<std::size_t _Int, class _Tp1, class _Tp2>
220 : constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&&
221 : get(std::pair<_Tp1, _Tp2>&& __in) noexcept
222 : { return __pair_get<_Int>::__move_get(std::move(__in)); }
223 :
224 : template<std::size_t _Int, class _Tp1, class _Tp2>
225 : constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
226 6602 : get(const std::pair<_Tp1, _Tp2>& __in) noexcept
227 6602 : { return __pair_get<_Int>::__const_get(__in); }
228 :
229 : template<std::size_t _Int, class _Tp1, class _Tp2>
230 : constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&&
231 : get(const std::pair<_Tp1, _Tp2>&& __in) noexcept
232 : { return __pair_get<_Int>::__const_move_get(std::move(__in)); }
233 :
234 : #if __cplusplus > 201103L
235 :
236 : #define __cpp_lib_tuples_by_type 201304
237 :
238 : template <typename _Tp, typename _Up>
239 : constexpr _Tp&
240 : get(pair<_Tp, _Up>& __p) noexcept
241 : { return __p.first; }
242 :
243 : template <typename _Tp, typename _Up>
244 : constexpr const _Tp&
245 : get(const pair<_Tp, _Up>& __p) noexcept
246 : { return __p.first; }
247 :
248 : template <typename _Tp, typename _Up>
249 : constexpr _Tp&&
250 : get(pair<_Tp, _Up>&& __p) noexcept
251 : { return std::move(__p.first); }
252 :
253 : template <typename _Tp, typename _Up>
254 : constexpr const _Tp&&
255 : get(const pair<_Tp, _Up>&& __p) noexcept
256 : { return std::move(__p.first); }
257 :
258 : template <typename _Tp, typename _Up>
259 : constexpr _Tp&
260 : get(pair<_Up, _Tp>& __p) noexcept
261 : { return __p.second; }
262 :
263 : template <typename _Tp, typename _Up>
264 : constexpr const _Tp&
265 : get(const pair<_Up, _Tp>& __p) noexcept
266 : { return __p.second; }
267 :
268 : template <typename _Tp, typename _Up>
269 : constexpr _Tp&&
270 : get(pair<_Up, _Tp>&& __p) noexcept
271 : { return std::move(__p.second); }
272 :
273 : template <typename _Tp, typename _Up>
274 : constexpr const _Tp&&
275 : get(const pair<_Up, _Tp>&& __p) noexcept
276 : { return std::move(__p.second); }
277 :
278 : #define __cpp_lib_exchange_function 201304
279 :
280 : /// Assign @p __new_val to @p __obj and return its previous value.
281 : template <typename _Tp, typename _Up = _Tp>
282 : inline _Tp
283 : exchange(_Tp& __obj, _Up&& __new_val)
284 : { return std::__exchange(__obj, std::forward<_Up>(__new_val)); }
285 : #endif
286 :
287 : // Stores a tuple of indices. Used by tuple and pair, and by bind() to
288 : // extract the elements in a tuple.
289 : template<size_t... _Indexes> struct _Index_tuple { };
290 :
291 : #ifdef __has_builtin
292 : # if __has_builtin(__make_integer_seq)
293 : # define _GLIBCXX_USE_MAKE_INTEGER_SEQ 1
294 : # endif
295 : #endif
296 :
297 : // Builds an _Index_tuple<0, 1, 2, ..., _Num-1>.
298 : template<size_t _Num>
299 : struct _Build_index_tuple
300 : {
301 : #if _GLIBCXX_USE_MAKE_INTEGER_SEQ
302 : template<typename, size_t... _Indices>
303 : using _IdxTuple = _Index_tuple<_Indices...>;
304 :
305 : using __type = __make_integer_seq<_IdxTuple, size_t, _Num>;
306 : #else
307 : using __type = _Index_tuple<__integer_pack(_Num)...>;
308 : #endif
309 : };
310 :
311 : #if __cplusplus > 201103L
312 :
313 : #define __cpp_lib_integer_sequence 201304
314 :
315 : /// Class template integer_sequence
316 : template<typename _Tp, _Tp... _Idx>
317 : struct integer_sequence
318 : {
319 : typedef _Tp value_type;
320 : static constexpr size_t size() noexcept { return sizeof...(_Idx); }
321 : };
322 :
323 : /// Alias template make_integer_sequence
324 : template<typename _Tp, _Tp _Num>
325 : using make_integer_sequence
326 : #if _GLIBCXX_USE_MAKE_INTEGER_SEQ
327 : = __make_integer_seq<integer_sequence, _Tp, _Num>;
328 : #else
329 : = integer_sequence<_Tp, __integer_pack(_Num)...>;
330 : #endif
331 :
332 : #undef _GLIBCXX_USE_MAKE_INTEGER_SEQ
333 :
334 : /// Alias template index_sequence
335 : template<size_t... _Idx>
336 : using index_sequence = integer_sequence<size_t, _Idx...>;
337 :
338 : /// Alias template make_index_sequence
339 : template<size_t _Num>
340 : using make_index_sequence = make_integer_sequence<size_t, _Num>;
341 :
342 : /// Alias template index_sequence_for
343 : template<typename... _Types>
344 : using index_sequence_for = make_index_sequence<sizeof...(_Types)>;
345 : #endif
346 :
347 : #if __cplusplus > 201402L
348 :
349 : struct in_place_t {
350 : explicit in_place_t() = default;
351 : };
352 :
353 : inline constexpr in_place_t in_place{};
354 :
355 : template<typename _Tp> struct in_place_type_t
356 : {
357 : explicit in_place_type_t() = default;
358 : };
359 :
360 : template<typename _Tp>
361 : inline constexpr in_place_type_t<_Tp> in_place_type{};
362 :
363 : template<size_t _Idx> struct in_place_index_t
364 : {
365 : explicit in_place_index_t() = default;
366 : };
367 :
368 : template<size_t _Idx>
369 : inline constexpr in_place_index_t<_Idx> in_place_index{};
370 :
371 : template<typename>
372 : struct __is_in_place_type_impl : false_type
373 : { };
374 :
375 : template<typename _Tp>
376 : struct __is_in_place_type_impl<in_place_type_t<_Tp>> : true_type
377 : { };
378 :
379 : template<typename _Tp>
380 : struct __is_in_place_type
381 : : public __is_in_place_type_impl<_Tp>
382 : { };
383 :
384 : #define __cpp_lib_as_const 201510
385 : template<typename _Tp>
386 : constexpr add_const_t<_Tp>& as_const(_Tp& __t) noexcept { return __t; }
387 :
388 : template<typename _Tp>
389 : void as_const(const _Tp&&) = delete;
390 :
391 : #endif // C++17
392 :
393 : _GLIBCXX_END_NAMESPACE_VERSION
394 : } // namespace
395 :
396 : #endif
397 :
398 : #endif /* _GLIBCXX_UTILITY */
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