1 | // unordered_map implementation -*- C++ -*- |
2 | |
3 | // Copyright (C) 2010-2019 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 | /** @file bits/unordered_map.h |
26 | * This is an internal header file, included by other library headers. |
27 | * Do not attempt to use it directly. @headername{unordered_map} |
28 | */ |
29 | |
30 | #ifndef _UNORDERED_MAP_H |
31 | #define _UNORDERED_MAP_H |
32 | |
33 | namespace std _GLIBCXX_VISIBILITY(default) |
34 | { |
35 | _GLIBCXX_BEGIN_NAMESPACE_VERSION |
36 | _GLIBCXX_BEGIN_NAMESPACE_CONTAINER |
37 | |
38 | /// Base types for unordered_map. |
39 | template<bool _Cache> |
40 | using __umap_traits = __detail::_Hashtable_traits<_Cache, false, true>; |
41 | |
42 | template<typename _Key, |
43 | typename _Tp, |
44 | typename _Hash = hash<_Key>, |
45 | typename _Pred = std::equal_to<_Key>, |
46 | typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >, |
47 | typename _Tr = __umap_traits<__cache_default<_Key, _Hash>::value>> |
48 | using __umap_hashtable = _Hashtable<_Key, std::pair<const _Key, _Tp>, |
49 | _Alloc, __detail::_Select1st, |
50 | _Pred, _Hash, |
51 | __detail::_Mod_range_hashing, |
52 | __detail::_Default_ranged_hash, |
53 | __detail::_Prime_rehash_policy, _Tr>; |
54 | |
55 | /// Base types for unordered_multimap. |
56 | template<bool _Cache> |
57 | using __ummap_traits = __detail::_Hashtable_traits<_Cache, false, false>; |
58 | |
59 | template<typename _Key, |
60 | typename _Tp, |
61 | typename _Hash = hash<_Key>, |
62 | typename _Pred = std::equal_to<_Key>, |
63 | typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >, |
64 | typename _Tr = __ummap_traits<__cache_default<_Key, _Hash>::value>> |
65 | using __ummap_hashtable = _Hashtable<_Key, std::pair<const _Key, _Tp>, |
66 | _Alloc, __detail::_Select1st, |
67 | _Pred, _Hash, |
68 | __detail::_Mod_range_hashing, |
69 | __detail::_Default_ranged_hash, |
70 | __detail::_Prime_rehash_policy, _Tr>; |
71 | |
72 | template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> |
73 | class unordered_multimap; |
74 | |
75 | /** |
76 | * @brief A standard container composed of unique keys (containing |
77 | * at most one of each key value) that associates values of another type |
78 | * with the keys. |
79 | * |
80 | * @ingroup unordered_associative_containers |
81 | * |
82 | * @tparam _Key Type of key objects. |
83 | * @tparam _Tp Type of mapped objects. |
84 | * @tparam _Hash Hashing function object type, defaults to hash<_Value>. |
85 | * @tparam _Pred Predicate function object type, defaults |
86 | * to equal_to<_Value>. |
87 | * @tparam _Alloc Allocator type, defaults to |
88 | * std::allocator<std::pair<const _Key, _Tp>>. |
89 | * |
90 | * Meets the requirements of a <a href="tables.html#65">container</a>, and |
91 | * <a href="tables.html#xx">unordered associative container</a> |
92 | * |
93 | * The resulting value type of the container is std::pair<const _Key, _Tp>. |
94 | * |
95 | * Base is _Hashtable, dispatched at compile time via template |
96 | * alias __umap_hashtable. |
97 | */ |
98 | template<typename _Key, typename _Tp, |
99 | typename _Hash = hash<_Key>, |
100 | typename _Pred = equal_to<_Key>, |
101 | typename _Alloc = allocator<std::pair<const _Key, _Tp>>> |
102 | class unordered_map |
103 | { |
104 | typedef __umap_hashtable<_Key, _Tp, _Hash, _Pred, _Alloc> _Hashtable; |
105 | _Hashtable _M_h; |
106 | |
107 | public: |
108 | // typedefs: |
109 | //@{ |
110 | /// Public typedefs. |
111 | typedef typename _Hashtable::key_type key_type; |
112 | typedef typename _Hashtable::value_type value_type; |
113 | typedef typename _Hashtable::mapped_type mapped_type; |
114 | typedef typename _Hashtable::hasher hasher; |
115 | typedef typename _Hashtable::key_equal key_equal; |
116 | typedef typename _Hashtable::allocator_type allocator_type; |
117 | //@} |
118 | |
119 | //@{ |
120 | /// Iterator-related typedefs. |
121 | typedef typename _Hashtable::pointer pointer; |
122 | typedef typename _Hashtable::const_pointer const_pointer; |
123 | typedef typename _Hashtable::reference reference; |
124 | typedef typename _Hashtable::const_reference const_reference; |
125 | typedef typename _Hashtable::iterator iterator; |
126 | typedef typename _Hashtable::const_iterator const_iterator; |
127 | typedef typename _Hashtable::local_iterator local_iterator; |
128 | typedef typename _Hashtable::const_local_iterator const_local_iterator; |
129 | typedef typename _Hashtable::size_type size_type; |
130 | typedef typename _Hashtable::difference_type difference_type; |
131 | //@} |
132 | |
133 | #if __cplusplus > 201402L |
134 | using node_type = typename _Hashtable::node_type; |
135 | using insert_return_type = typename _Hashtable::insert_return_type; |
136 | #endif |
137 | |
138 | //construct/destroy/copy |
139 | |
140 | /// Default constructor. |
141 | unordered_map() = default; |
142 | |
143 | /** |
144 | * @brief Default constructor creates no elements. |
145 | * @param __n Minimal initial number of buckets. |
146 | * @param __hf A hash functor. |
147 | * @param __eql A key equality functor. |
148 | * @param __a An allocator object. |
149 | */ |
150 | explicit |
151 | unordered_map(size_type __n, |
152 | const hasher& __hf = hasher(), |
153 | const key_equal& __eql = key_equal(), |
154 | const allocator_type& __a = allocator_type()) |
155 | : _M_h(__n, __hf, __eql, __a) |
156 | { } |
157 | |
158 | /** |
159 | * @brief Builds an %unordered_map from a range. |
160 | * @param __first An input iterator. |
161 | * @param __last An input iterator. |
162 | * @param __n Minimal initial number of buckets. |
163 | * @param __hf A hash functor. |
164 | * @param __eql A key equality functor. |
165 | * @param __a An allocator object. |
166 | * |
167 | * Create an %unordered_map consisting of copies of the elements from |
168 | * [__first,__last). This is linear in N (where N is |
169 | * distance(__first,__last)). |
170 | */ |
171 | template<typename _InputIterator> |
172 | unordered_map(_InputIterator __first, _InputIterator __last, |
173 | size_type __n = 0, |
174 | const hasher& __hf = hasher(), |
175 | const key_equal& __eql = key_equal(), |
176 | const allocator_type& __a = allocator_type()) |
177 | : _M_h(__first, __last, __n, __hf, __eql, __a) |
178 | { } |
179 | |
180 | /// Copy constructor. |
181 | unordered_map(const unordered_map&) = default; |
182 | |
183 | /// Move constructor. |
184 | unordered_map(unordered_map&&) = default; |
185 | |
186 | /** |
187 | * @brief Creates an %unordered_map with no elements. |
188 | * @param __a An allocator object. |
189 | */ |
190 | explicit |
191 | unordered_map(const allocator_type& __a) |
192 | : _M_h(__a) |
193 | { } |
194 | |
195 | /* |
196 | * @brief Copy constructor with allocator argument. |
197 | * @param __uset Input %unordered_map to copy. |
198 | * @param __a An allocator object. |
199 | */ |
200 | unordered_map(const unordered_map& __umap, |
201 | const allocator_type& __a) |
202 | : _M_h(__umap._M_h, __a) |
203 | { } |
204 | |
205 | /* |
206 | * @brief Move constructor with allocator argument. |
207 | * @param __uset Input %unordered_map to move. |
208 | * @param __a An allocator object. |
209 | */ |
210 | unordered_map(unordered_map&& __umap, |
211 | const allocator_type& __a) |
212 | : _M_h(std::move(__umap._M_h), __a) |
213 | { } |
214 | |
215 | /** |
216 | * @brief Builds an %unordered_map from an initializer_list. |
217 | * @param __l An initializer_list. |
218 | * @param __n Minimal initial number of buckets. |
219 | * @param __hf A hash functor. |
220 | * @param __eql A key equality functor. |
221 | * @param __a An allocator object. |
222 | * |
223 | * Create an %unordered_map consisting of copies of the elements in the |
224 | * list. This is linear in N (where N is @a __l.size()). |
225 | */ |
226 | unordered_map(initializer_list<value_type> __l, |
227 | size_type __n = 0, |
228 | const hasher& __hf = hasher(), |
229 | const key_equal& __eql = key_equal(), |
230 | const allocator_type& __a = allocator_type()) |
231 | : _M_h(__l, __n, __hf, __eql, __a) |
232 | { } |
233 | |
234 | unordered_map(size_type __n, const allocator_type& __a) |
235 | : unordered_map(__n, hasher(), key_equal(), __a) |
236 | { } |
237 | |
238 | unordered_map(size_type __n, const hasher& __hf, |
239 | const allocator_type& __a) |
240 | : unordered_map(__n, __hf, key_equal(), __a) |
241 | { } |
242 | |
243 | template<typename _InputIterator> |
244 | unordered_map(_InputIterator __first, _InputIterator __last, |
245 | size_type __n, |
246 | const allocator_type& __a) |
247 | : unordered_map(__first, __last, __n, hasher(), key_equal(), __a) |
248 | { } |
249 | |
250 | template<typename _InputIterator> |
251 | unordered_map(_InputIterator __first, _InputIterator __last, |
252 | size_type __n, const hasher& __hf, |
253 | const allocator_type& __a) |
254 | : unordered_map(__first, __last, __n, __hf, key_equal(), __a) |
255 | { } |
256 | |
257 | unordered_map(initializer_list<value_type> __l, |
258 | size_type __n, |
259 | const allocator_type& __a) |
260 | : unordered_map(__l, __n, hasher(), key_equal(), __a) |
261 | { } |
262 | |
263 | unordered_map(initializer_list<value_type> __l, |
264 | size_type __n, const hasher& __hf, |
265 | const allocator_type& __a) |
266 | : unordered_map(__l, __n, __hf, key_equal(), __a) |
267 | { } |
268 | |
269 | /// Copy assignment operator. |
270 | unordered_map& |
271 | operator=(const unordered_map&) = default; |
272 | |
273 | /// Move assignment operator. |
274 | unordered_map& |
275 | operator=(unordered_map&&) = default; |
276 | |
277 | /** |
278 | * @brief %Unordered_map list assignment operator. |
279 | * @param __l An initializer_list. |
280 | * |
281 | * This function fills an %unordered_map with copies of the elements in |
282 | * the initializer list @a __l. |
283 | * |
284 | * Note that the assignment completely changes the %unordered_map and |
285 | * that the resulting %unordered_map's size is the same as the number |
286 | * of elements assigned. |
287 | */ |
288 | unordered_map& |
289 | operator=(initializer_list<value_type> __l) |
290 | { |
291 | _M_h = __l; |
292 | return *this; |
293 | } |
294 | |
295 | /// Returns the allocator object used by the %unordered_map. |
296 | allocator_type |
297 | get_allocator() const noexcept |
298 | { return _M_h.get_allocator(); } |
299 | |
300 | // size and capacity: |
301 | |
302 | /// Returns true if the %unordered_map is empty. |
303 | _GLIBCXX_NODISCARD bool |
304 | empty() const noexcept |
305 | { return _M_h.empty(); } |
306 | |
307 | /// Returns the size of the %unordered_map. |
308 | size_type |
309 | size() const noexcept |
310 | { return _M_h.size(); } |
311 | |
312 | /// Returns the maximum size of the %unordered_map. |
313 | size_type |
314 | max_size() const noexcept |
315 | { return _M_h.max_size(); } |
316 | |
317 | // iterators. |
318 | |
319 | /** |
320 | * Returns a read/write iterator that points to the first element in the |
321 | * %unordered_map. |
322 | */ |
323 | iterator |
324 | begin() noexcept |
325 | { return _M_h.begin(); } |
326 | |
327 | //@{ |
328 | /** |
329 | * Returns a read-only (constant) iterator that points to the first |
330 | * element in the %unordered_map. |
331 | */ |
332 | const_iterator |
333 | begin() const noexcept |
334 | { return _M_h.begin(); } |
335 | |
336 | const_iterator |
337 | cbegin() const noexcept |
338 | { return _M_h.begin(); } |
339 | //@} |
340 | |
341 | /** |
342 | * Returns a read/write iterator that points one past the last element in |
343 | * the %unordered_map. |
344 | */ |
345 | iterator |
346 | end() noexcept |
347 | { return _M_h.end(); } |
348 | |
349 | //@{ |
350 | /** |
351 | * Returns a read-only (constant) iterator that points one past the last |
352 | * element in the %unordered_map. |
353 | */ |
354 | const_iterator |
355 | end() const noexcept |
356 | { return _M_h.end(); } |
357 | |
358 | const_iterator |
359 | cend() const noexcept |
360 | { return _M_h.end(); } |
361 | //@} |
362 | |
363 | // modifiers. |
364 | |
365 | /** |
366 | * @brief Attempts to build and insert a std::pair into the |
367 | * %unordered_map. |
368 | * |
369 | * @param __args Arguments used to generate a new pair instance (see |
370 | * std::piecewise_contruct for passing arguments to each |
371 | * part of the pair constructor). |
372 | * |
373 | * @return A pair, of which the first element is an iterator that points |
374 | * to the possibly inserted pair, and the second is a bool that |
375 | * is true if the pair was actually inserted. |
376 | * |
377 | * This function attempts to build and insert a (key, value) %pair into |
378 | * the %unordered_map. |
379 | * An %unordered_map relies on unique keys and thus a %pair is only |
380 | * inserted if its first element (the key) is not already present in the |
381 | * %unordered_map. |
382 | * |
383 | * Insertion requires amortized constant time. |
384 | */ |
385 | template<typename... _Args> |
386 | std::pair<iterator, bool> |
387 | emplace(_Args&&... __args) |
388 | { return _M_h.emplace(std::forward<_Args>(__args)...); } |
389 | |
390 | /** |
391 | * @brief Attempts to build and insert a std::pair into the |
392 | * %unordered_map. |
393 | * |
394 | * @param __pos An iterator that serves as a hint as to where the pair |
395 | * should be inserted. |
396 | * @param __args Arguments used to generate a new pair instance (see |
397 | * std::piecewise_contruct for passing arguments to each |
398 | * part of the pair constructor). |
399 | * @return An iterator that points to the element with key of the |
400 | * std::pair built from @a __args (may or may not be that |
401 | * std::pair). |
402 | * |
403 | * This function is not concerned about whether the insertion took place, |
404 | * and thus does not return a boolean like the single-argument emplace() |
405 | * does. |
406 | * Note that the first parameter is only a hint and can potentially |
407 | * improve the performance of the insertion process. A bad hint would |
408 | * cause no gains in efficiency. |
409 | * |
410 | * See |
411 | * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints |
412 | * for more on @a hinting. |
413 | * |
414 | * Insertion requires amortized constant time. |
415 | */ |
416 | template<typename... _Args> |
417 | iterator |
418 | emplace_hint(const_iterator __pos, _Args&&... __args) |
419 | { return _M_h.emplace_hint(__pos, std::forward<_Args>(__args)...); } |
420 | |
421 | #if __cplusplus > 201402L |
422 | /// Extract a node. |
423 | node_type |
424 | (const_iterator __pos) |
425 | { |
426 | __glibcxx_assert(__pos != end()); |
427 | return _M_h.extract(__pos); |
428 | } |
429 | |
430 | /// Extract a node. |
431 | node_type |
432 | (const key_type& __key) |
433 | { return _M_h.extract(__key); } |
434 | |
435 | /// Re-insert an extracted node. |
436 | insert_return_type |
437 | insert(node_type&& __nh) |
438 | { return _M_h._M_reinsert_node(std::move(__nh)); } |
439 | |
440 | /// Re-insert an extracted node. |
441 | iterator |
442 | insert(const_iterator, node_type&& __nh) |
443 | { return _M_h._M_reinsert_node(std::move(__nh)).position; } |
444 | |
445 | #define __cpp_lib_unordered_map_try_emplace 201411 |
446 | /** |
447 | * @brief Attempts to build and insert a std::pair into the |
448 | * %unordered_map. |
449 | * |
450 | * @param __k Key to use for finding a possibly existing pair in |
451 | * the unordered_map. |
452 | * @param __args Arguments used to generate the .second for a |
453 | * new pair instance. |
454 | * |
455 | * @return A pair, of which the first element is an iterator that points |
456 | * to the possibly inserted pair, and the second is a bool that |
457 | * is true if the pair was actually inserted. |
458 | * |
459 | * This function attempts to build and insert a (key, value) %pair into |
460 | * the %unordered_map. |
461 | * An %unordered_map relies on unique keys and thus a %pair is only |
462 | * inserted if its first element (the key) is not already present in the |
463 | * %unordered_map. |
464 | * If a %pair is not inserted, this function has no effect. |
465 | * |
466 | * Insertion requires amortized constant time. |
467 | */ |
468 | template <typename... _Args> |
469 | pair<iterator, bool> |
470 | try_emplace(const key_type& __k, _Args&&... __args) |
471 | { |
472 | iterator __i = find(__k); |
473 | if (__i == end()) |
474 | { |
475 | __i = emplace(std::piecewise_construct, |
476 | std::forward_as_tuple(__k), |
477 | std::forward_as_tuple( |
478 | std::forward<_Args>(__args)...)) |
479 | .first; |
480 | return {__i, true}; |
481 | } |
482 | return {__i, false}; |
483 | } |
484 | |
485 | // move-capable overload |
486 | template <typename... _Args> |
487 | pair<iterator, bool> |
488 | try_emplace(key_type&& __k, _Args&&... __args) |
489 | { |
490 | iterator __i = find(__k); |
491 | if (__i == end()) |
492 | { |
493 | __i = emplace(std::piecewise_construct, |
494 | std::forward_as_tuple(std::move(__k)), |
495 | std::forward_as_tuple( |
496 | std::forward<_Args>(__args)...)) |
497 | .first; |
498 | return {__i, true}; |
499 | } |
500 | return {__i, false}; |
501 | } |
502 | |
503 | /** |
504 | * @brief Attempts to build and insert a std::pair into the |
505 | * %unordered_map. |
506 | * |
507 | * @param __hint An iterator that serves as a hint as to where the pair |
508 | * should be inserted. |
509 | * @param __k Key to use for finding a possibly existing pair in |
510 | * the unordered_map. |
511 | * @param __args Arguments used to generate the .second for a |
512 | * new pair instance. |
513 | * @return An iterator that points to the element with key of the |
514 | * std::pair built from @a __args (may or may not be that |
515 | * std::pair). |
516 | * |
517 | * This function is not concerned about whether the insertion took place, |
518 | * and thus does not return a boolean like the single-argument emplace() |
519 | * does. However, if insertion did not take place, |
520 | * this function has no effect. |
521 | * Note that the first parameter is only a hint and can potentially |
522 | * improve the performance of the insertion process. A bad hint would |
523 | * cause no gains in efficiency. |
524 | * |
525 | * See |
526 | * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints |
527 | * for more on @a hinting. |
528 | * |
529 | * Insertion requires amortized constant time. |
530 | */ |
531 | template <typename... _Args> |
532 | iterator |
533 | try_emplace(const_iterator __hint, const key_type& __k, |
534 | _Args&&... __args) |
535 | { |
536 | iterator __i = find(__k); |
537 | if (__i == end()) |
538 | __i = emplace_hint(__hint, std::piecewise_construct, |
539 | std::forward_as_tuple(__k), |
540 | std::forward_as_tuple( |
541 | std::forward<_Args>(__args)...)); |
542 | return __i; |
543 | } |
544 | |
545 | // move-capable overload |
546 | template <typename... _Args> |
547 | iterator |
548 | try_emplace(const_iterator __hint, key_type&& __k, _Args&&... __args) |
549 | { |
550 | iterator __i = find(__k); |
551 | if (__i == end()) |
552 | __i = emplace_hint(__hint, std::piecewise_construct, |
553 | std::forward_as_tuple(std::move(__k)), |
554 | std::forward_as_tuple( |
555 | std::forward<_Args>(__args)...)); |
556 | return __i; |
557 | } |
558 | #endif // C++17 |
559 | |
560 | //@{ |
561 | /** |
562 | * @brief Attempts to insert a std::pair into the %unordered_map. |
563 | |
564 | * @param __x Pair to be inserted (see std::make_pair for easy |
565 | * creation of pairs). |
566 | * |
567 | * @return A pair, of which the first element is an iterator that |
568 | * points to the possibly inserted pair, and the second is |
569 | * a bool that is true if the pair was actually inserted. |
570 | * |
571 | * This function attempts to insert a (key, value) %pair into the |
572 | * %unordered_map. An %unordered_map relies on unique keys and thus a |
573 | * %pair is only inserted if its first element (the key) is not already |
574 | * present in the %unordered_map. |
575 | * |
576 | * Insertion requires amortized constant time. |
577 | */ |
578 | std::pair<iterator, bool> |
579 | insert(const value_type& __x) |
580 | { return _M_h.insert(__x); } |
581 | |
582 | // _GLIBCXX_RESOLVE_LIB_DEFECTS |
583 | // 2354. Unnecessary copying when inserting into maps with braced-init |
584 | std::pair<iterator, bool> |
585 | insert(value_type&& __x) |
586 | { return _M_h.insert(std::move(__x)); } |
587 | |
588 | template<typename _Pair> |
589 | __enable_if_t<is_constructible<value_type, _Pair&&>::value, |
590 | pair<iterator, bool>> |
591 | insert(_Pair&& __x) |
592 | { return _M_h.emplace(std::forward<_Pair>(__x)); } |
593 | //@} |
594 | |
595 | //@{ |
596 | /** |
597 | * @brief Attempts to insert a std::pair into the %unordered_map. |
598 | * @param __hint An iterator that serves as a hint as to where the |
599 | * pair should be inserted. |
600 | * @param __x Pair to be inserted (see std::make_pair for easy creation |
601 | * of pairs). |
602 | * @return An iterator that points to the element with key of |
603 | * @a __x (may or may not be the %pair passed in). |
604 | * |
605 | * This function is not concerned about whether the insertion took place, |
606 | * and thus does not return a boolean like the single-argument insert() |
607 | * does. Note that the first parameter is only a hint and can |
608 | * potentially improve the performance of the insertion process. A bad |
609 | * hint would cause no gains in efficiency. |
610 | * |
611 | * See |
612 | * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints |
613 | * for more on @a hinting. |
614 | * |
615 | * Insertion requires amortized constant time. |
616 | */ |
617 | iterator |
618 | insert(const_iterator __hint, const value_type& __x) |
619 | { return _M_h.insert(__hint, __x); } |
620 | |
621 | // _GLIBCXX_RESOLVE_LIB_DEFECTS |
622 | // 2354. Unnecessary copying when inserting into maps with braced-init |
623 | iterator |
624 | insert(const_iterator __hint, value_type&& __x) |
625 | { return _M_h.insert(__hint, std::move(__x)); } |
626 | |
627 | template<typename _Pair> |
628 | __enable_if_t<is_constructible<value_type, _Pair&&>::value, iterator> |
629 | insert(const_iterator __hint, _Pair&& __x) |
630 | { return _M_h.emplace_hint(__hint, std::forward<_Pair>(__x)); } |
631 | //@} |
632 | |
633 | /** |
634 | * @brief A template function that attempts to insert a range of |
635 | * elements. |
636 | * @param __first Iterator pointing to the start of the range to be |
637 | * inserted. |
638 | * @param __last Iterator pointing to the end of the range. |
639 | * |
640 | * Complexity similar to that of the range constructor. |
641 | */ |
642 | template<typename _InputIterator> |
643 | void |
644 | insert(_InputIterator __first, _InputIterator __last) |
645 | { _M_h.insert(__first, __last); } |
646 | |
647 | /** |
648 | * @brief Attempts to insert a list of elements into the %unordered_map. |
649 | * @param __l A std::initializer_list<value_type> of elements |
650 | * to be inserted. |
651 | * |
652 | * Complexity similar to that of the range constructor. |
653 | */ |
654 | void |
655 | insert(initializer_list<value_type> __l) |
656 | { _M_h.insert(__l); } |
657 | |
658 | |
659 | #if __cplusplus > 201402L |
660 | #define __cpp_lib_unordered_map_insertion 201411 |
661 | /** |
662 | * @brief Attempts to insert a std::pair into the %unordered_map. |
663 | * @param __k Key to use for finding a possibly existing pair in |
664 | * the map. |
665 | * @param __obj Argument used to generate the .second for a pair |
666 | * instance. |
667 | * |
668 | * @return A pair, of which the first element is an iterator that |
669 | * points to the possibly inserted pair, and the second is |
670 | * a bool that is true if the pair was actually inserted. |
671 | * |
672 | * This function attempts to insert a (key, value) %pair into the |
673 | * %unordered_map. An %unordered_map relies on unique keys and thus a |
674 | * %pair is only inserted if its first element (the key) is not already |
675 | * present in the %unordered_map. |
676 | * If the %pair was already in the %unordered_map, the .second of |
677 | * the %pair is assigned from __obj. |
678 | * |
679 | * Insertion requires amortized constant time. |
680 | */ |
681 | template <typename _Obj> |
682 | pair<iterator, bool> |
683 | insert_or_assign(const key_type& __k, _Obj&& __obj) |
684 | { |
685 | iterator __i = find(__k); |
686 | if (__i == end()) |
687 | { |
688 | __i = emplace(std::piecewise_construct, |
689 | std::forward_as_tuple(__k), |
690 | std::forward_as_tuple(std::forward<_Obj>(__obj))) |
691 | .first; |
692 | return {__i, true}; |
693 | } |
694 | (*__i).second = std::forward<_Obj>(__obj); |
695 | return {__i, false}; |
696 | } |
697 | |
698 | // move-capable overload |
699 | template <typename _Obj> |
700 | pair<iterator, bool> |
701 | insert_or_assign(key_type&& __k, _Obj&& __obj) |
702 | { |
703 | iterator __i = find(__k); |
704 | if (__i == end()) |
705 | { |
706 | __i = emplace(std::piecewise_construct, |
707 | std::forward_as_tuple(std::move(__k)), |
708 | std::forward_as_tuple(std::forward<_Obj>(__obj))) |
709 | .first; |
710 | return {__i, true}; |
711 | } |
712 | (*__i).second = std::forward<_Obj>(__obj); |
713 | return {__i, false}; |
714 | } |
715 | |
716 | /** |
717 | * @brief Attempts to insert a std::pair into the %unordered_map. |
718 | * @param __hint An iterator that serves as a hint as to where the |
719 | * pair should be inserted. |
720 | * @param __k Key to use for finding a possibly existing pair in |
721 | * the unordered_map. |
722 | * @param __obj Argument used to generate the .second for a pair |
723 | * instance. |
724 | * @return An iterator that points to the element with key of |
725 | * @a __x (may or may not be the %pair passed in). |
726 | * |
727 | * This function is not concerned about whether the insertion took place, |
728 | * and thus does not return a boolean like the single-argument insert() |
729 | * does. |
730 | * If the %pair was already in the %unordered map, the .second of |
731 | * the %pair is assigned from __obj. |
732 | * Note that the first parameter is only a hint and can |
733 | * potentially improve the performance of the insertion process. A bad |
734 | * hint would cause no gains in efficiency. |
735 | * |
736 | * See |
737 | * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints |
738 | * for more on @a hinting. |
739 | * |
740 | * Insertion requires amortized constant time. |
741 | */ |
742 | template <typename _Obj> |
743 | iterator |
744 | insert_or_assign(const_iterator __hint, const key_type& __k, |
745 | _Obj&& __obj) |
746 | { |
747 | iterator __i = find(__k); |
748 | if (__i == end()) |
749 | { |
750 | return emplace_hint(__hint, std::piecewise_construct, |
751 | std::forward_as_tuple(__k), |
752 | std::forward_as_tuple( |
753 | std::forward<_Obj>(__obj))); |
754 | } |
755 | (*__i).second = std::forward<_Obj>(__obj); |
756 | return __i; |
757 | } |
758 | |
759 | // move-capable overload |
760 | template <typename _Obj> |
761 | iterator |
762 | insert_or_assign(const_iterator __hint, key_type&& __k, _Obj&& __obj) |
763 | { |
764 | iterator __i = find(__k); |
765 | if (__i == end()) |
766 | { |
767 | return emplace_hint(__hint, std::piecewise_construct, |
768 | std::forward_as_tuple(std::move(__k)), |
769 | std::forward_as_tuple( |
770 | std::forward<_Obj>(__obj))); |
771 | } |
772 | (*__i).second = std::forward<_Obj>(__obj); |
773 | return __i; |
774 | } |
775 | #endif |
776 | |
777 | //@{ |
778 | /** |
779 | * @brief Erases an element from an %unordered_map. |
780 | * @param __position An iterator pointing to the element to be erased. |
781 | * @return An iterator pointing to the element immediately following |
782 | * @a __position prior to the element being erased. If no such |
783 | * element exists, end() is returned. |
784 | * |
785 | * This function erases an element, pointed to by the given iterator, |
786 | * from an %unordered_map. |
787 | * Note that this function only erases the element, and that if the |
788 | * element is itself a pointer, the pointed-to memory is not touched in |
789 | * any way. Managing the pointer is the user's responsibility. |
790 | */ |
791 | iterator |
792 | erase(const_iterator __position) |
793 | { return _M_h.erase(__position); } |
794 | |
795 | // LWG 2059. |
796 | iterator |
797 | erase(iterator __position) |
798 | { return _M_h.erase(__position); } |
799 | //@} |
800 | |
801 | /** |
802 | * @brief Erases elements according to the provided key. |
803 | * @param __x Key of element to be erased. |
804 | * @return The number of elements erased. |
805 | * |
806 | * This function erases all the elements located by the given key from |
807 | * an %unordered_map. For an %unordered_map the result of this function |
808 | * can only be 0 (not present) or 1 (present). |
809 | * Note that this function only erases the element, and that if the |
810 | * element is itself a pointer, the pointed-to memory is not touched in |
811 | * any way. Managing the pointer is the user's responsibility. |
812 | */ |
813 | size_type |
814 | erase(const key_type& __x) |
815 | { return _M_h.erase(__x); } |
816 | |
817 | /** |
818 | * @brief Erases a [__first,__last) range of elements from an |
819 | * %unordered_map. |
820 | * @param __first Iterator pointing to the start of the range to be |
821 | * erased. |
822 | * @param __last Iterator pointing to the end of the range to |
823 | * be erased. |
824 | * @return The iterator @a __last. |
825 | * |
826 | * This function erases a sequence of elements from an %unordered_map. |
827 | * Note that this function only erases the elements, and that if |
828 | * the element is itself a pointer, the pointed-to memory is not touched |
829 | * in any way. Managing the pointer is the user's responsibility. |
830 | */ |
831 | iterator |
832 | erase(const_iterator __first, const_iterator __last) |
833 | { return _M_h.erase(__first, __last); } |
834 | |
835 | /** |
836 | * Erases all elements in an %unordered_map. |
837 | * Note that this function only erases the elements, and that if the |
838 | * elements themselves are pointers, the pointed-to memory is not touched |
839 | * in any way. Managing the pointer is the user's responsibility. |
840 | */ |
841 | void |
842 | clear() noexcept |
843 | { _M_h.clear(); } |
844 | |
845 | /** |
846 | * @brief Swaps data with another %unordered_map. |
847 | * @param __x An %unordered_map of the same element and allocator |
848 | * types. |
849 | * |
850 | * This exchanges the elements between two %unordered_map in constant |
851 | * time. |
852 | * Note that the global std::swap() function is specialized such that |
853 | * std::swap(m1,m2) will feed to this function. |
854 | */ |
855 | void |
856 | swap(unordered_map& __x) |
857 | noexcept( noexcept(_M_h.swap(__x._M_h)) ) |
858 | { _M_h.swap(__x._M_h); } |
859 | |
860 | #if __cplusplus > 201402L |
861 | template<typename, typename, typename> |
862 | friend class std::_Hash_merge_helper; |
863 | |
864 | template<typename _H2, typename _P2> |
865 | void |
866 | merge(unordered_map<_Key, _Tp, _H2, _P2, _Alloc>& __source) |
867 | { |
868 | using _Merge_helper = _Hash_merge_helper<unordered_map, _H2, _P2>; |
869 | _M_h._M_merge_unique(_Merge_helper::_S_get_table(__source)); |
870 | } |
871 | |
872 | template<typename _H2, typename _P2> |
873 | void |
874 | merge(unordered_map<_Key, _Tp, _H2, _P2, _Alloc>&& __source) |
875 | { merge(__source); } |
876 | |
877 | template<typename _H2, typename _P2> |
878 | void |
879 | merge(unordered_multimap<_Key, _Tp, _H2, _P2, _Alloc>& __source) |
880 | { |
881 | using _Merge_helper = _Hash_merge_helper<unordered_map, _H2, _P2>; |
882 | _M_h._M_merge_unique(_Merge_helper::_S_get_table(__source)); |
883 | } |
884 | |
885 | template<typename _H2, typename _P2> |
886 | void |
887 | merge(unordered_multimap<_Key, _Tp, _H2, _P2, _Alloc>&& __source) |
888 | { merge(__source); } |
889 | #endif // C++17 |
890 | |
891 | // observers. |
892 | |
893 | /// Returns the hash functor object with which the %unordered_map was |
894 | /// constructed. |
895 | hasher |
896 | hash_function() const |
897 | { return _M_h.hash_function(); } |
898 | |
899 | /// Returns the key comparison object with which the %unordered_map was |
900 | /// constructed. |
901 | key_equal |
902 | key_eq() const |
903 | { return _M_h.key_eq(); } |
904 | |
905 | // lookup. |
906 | |
907 | //@{ |
908 | /** |
909 | * @brief Tries to locate an element in an %unordered_map. |
910 | * @param __x Key to be located. |
911 | * @return Iterator pointing to sought-after element, or end() if not |
912 | * found. |
913 | * |
914 | * This function takes a key and tries to locate the element with which |
915 | * the key matches. If successful the function returns an iterator |
916 | * pointing to the sought after element. If unsuccessful it returns the |
917 | * past-the-end ( @c end() ) iterator. |
918 | */ |
919 | iterator |
920 | find(const key_type& __x) |
921 | { return _M_h.find(__x); } |
922 | |
923 | const_iterator |
924 | find(const key_type& __x) const |
925 | { return _M_h.find(__x); } |
926 | //@} |
927 | |
928 | /** |
929 | * @brief Finds the number of elements. |
930 | * @param __x Key to count. |
931 | * @return Number of elements with specified key. |
932 | * |
933 | * This function only makes sense for %unordered_multimap; for |
934 | * %unordered_map the result will either be 0 (not present) or 1 |
935 | * (present). |
936 | */ |
937 | size_type |
938 | count(const key_type& __x) const |
939 | { return _M_h.count(__x); } |
940 | |
941 | #if __cplusplus > 201703L |
942 | /** |
943 | * @brief Finds whether an element with the given key exists. |
944 | * @param __x Key of elements to be located. |
945 | * @return True if there is any element with the specified key. |
946 | */ |
947 | bool |
948 | contains(const key_type& __x) const |
949 | { return _M_h.find(__x) != _M_h.end(); } |
950 | #endif |
951 | |
952 | //@{ |
953 | /** |
954 | * @brief Finds a subsequence matching given key. |
955 | * @param __x Key to be located. |
956 | * @return Pair of iterators that possibly points to the subsequence |
957 | * matching given key. |
958 | * |
959 | * This function probably only makes sense for %unordered_multimap. |
960 | */ |
961 | std::pair<iterator, iterator> |
962 | equal_range(const key_type& __x) |
963 | { return _M_h.equal_range(__x); } |
964 | |
965 | std::pair<const_iterator, const_iterator> |
966 | equal_range(const key_type& __x) const |
967 | { return _M_h.equal_range(__x); } |
968 | //@} |
969 | |
970 | //@{ |
971 | /** |
972 | * @brief Subscript ( @c [] ) access to %unordered_map data. |
973 | * @param __k The key for which data should be retrieved. |
974 | * @return A reference to the data of the (key,data) %pair. |
975 | * |
976 | * Allows for easy lookup with the subscript ( @c [] )operator. Returns |
977 | * data associated with the key specified in subscript. If the key does |
978 | * not exist, a pair with that key is created using default values, which |
979 | * is then returned. |
980 | * |
981 | * Lookup requires constant time. |
982 | */ |
983 | mapped_type& |
984 | operator[](const key_type& __k) |
985 | { return _M_h[__k]; } |
986 | |
987 | mapped_type& |
988 | operator[](key_type&& __k) |
989 | { return _M_h[std::move(__k)]; } |
990 | //@} |
991 | |
992 | //@{ |
993 | /** |
994 | * @brief Access to %unordered_map data. |
995 | * @param __k The key for which data should be retrieved. |
996 | * @return A reference to the data whose key is equal to @a __k, if |
997 | * such a data is present in the %unordered_map. |
998 | * @throw std::out_of_range If no such data is present. |
999 | */ |
1000 | mapped_type& |
1001 | at(const key_type& __k) |
1002 | { return _M_h.at(__k); } |
1003 | |
1004 | const mapped_type& |
1005 | at(const key_type& __k) const |
1006 | { return _M_h.at(__k); } |
1007 | //@} |
1008 | |
1009 | // bucket interface. |
1010 | |
1011 | /// Returns the number of buckets of the %unordered_map. |
1012 | size_type |
1013 | bucket_count() const noexcept |
1014 | { return _M_h.bucket_count(); } |
1015 | |
1016 | /// Returns the maximum number of buckets of the %unordered_map. |
1017 | size_type |
1018 | max_bucket_count() const noexcept |
1019 | { return _M_h.max_bucket_count(); } |
1020 | |
1021 | /* |
1022 | * @brief Returns the number of elements in a given bucket. |
1023 | * @param __n A bucket index. |
1024 | * @return The number of elements in the bucket. |
1025 | */ |
1026 | size_type |
1027 | bucket_size(size_type __n) const |
1028 | { return _M_h.bucket_size(__n); } |
1029 | |
1030 | /* |
1031 | * @brief Returns the bucket index of a given element. |
1032 | * @param __key A key instance. |
1033 | * @return The key bucket index. |
1034 | */ |
1035 | size_type |
1036 | bucket(const key_type& __key) const |
1037 | { return _M_h.bucket(__key); } |
1038 | |
1039 | /** |
1040 | * @brief Returns a read/write iterator pointing to the first bucket |
1041 | * element. |
1042 | * @param __n The bucket index. |
1043 | * @return A read/write local iterator. |
1044 | */ |
1045 | local_iterator |
1046 | begin(size_type __n) |
1047 | { return _M_h.begin(__n); } |
1048 | |
1049 | //@{ |
1050 | /** |
1051 | * @brief Returns a read-only (constant) iterator pointing to the first |
1052 | * bucket element. |
1053 | * @param __n The bucket index. |
1054 | * @return A read-only local iterator. |
1055 | */ |
1056 | const_local_iterator |
1057 | begin(size_type __n) const |
1058 | { return _M_h.begin(__n); } |
1059 | |
1060 | const_local_iterator |
1061 | cbegin(size_type __n) const |
1062 | { return _M_h.cbegin(__n); } |
1063 | //@} |
1064 | |
1065 | /** |
1066 | * @brief Returns a read/write iterator pointing to one past the last |
1067 | * bucket elements. |
1068 | * @param __n The bucket index. |
1069 | * @return A read/write local iterator. |
1070 | */ |
1071 | local_iterator |
1072 | end(size_type __n) |
1073 | { return _M_h.end(__n); } |
1074 | |
1075 | //@{ |
1076 | /** |
1077 | * @brief Returns a read-only (constant) iterator pointing to one past |
1078 | * the last bucket elements. |
1079 | * @param __n The bucket index. |
1080 | * @return A read-only local iterator. |
1081 | */ |
1082 | const_local_iterator |
1083 | end(size_type __n) const |
1084 | { return _M_h.end(__n); } |
1085 | |
1086 | const_local_iterator |
1087 | cend(size_type __n) const |
1088 | { return _M_h.cend(__n); } |
1089 | //@} |
1090 | |
1091 | // hash policy. |
1092 | |
1093 | /// Returns the average number of elements per bucket. |
1094 | float |
1095 | load_factor() const noexcept |
1096 | { return _M_h.load_factor(); } |
1097 | |
1098 | /// Returns a positive number that the %unordered_map tries to keep the |
1099 | /// load factor less than or equal to. |
1100 | float |
1101 | max_load_factor() const noexcept |
1102 | { return _M_h.max_load_factor(); } |
1103 | |
1104 | /** |
1105 | * @brief Change the %unordered_map maximum load factor. |
1106 | * @param __z The new maximum load factor. |
1107 | */ |
1108 | void |
1109 | max_load_factor(float __z) |
1110 | { _M_h.max_load_factor(__z); } |
1111 | |
1112 | /** |
1113 | * @brief May rehash the %unordered_map. |
1114 | * @param __n The new number of buckets. |
1115 | * |
1116 | * Rehash will occur only if the new number of buckets respect the |
1117 | * %unordered_map maximum load factor. |
1118 | */ |
1119 | void |
1120 | rehash(size_type __n) |
1121 | { _M_h.rehash(__n); } |
1122 | |
1123 | /** |
1124 | * @brief Prepare the %unordered_map for a specified number of |
1125 | * elements. |
1126 | * @param __n Number of elements required. |
1127 | * |
1128 | * Same as rehash(ceil(n / max_load_factor())). |
1129 | */ |
1130 | void |
1131 | reserve(size_type __n) |
1132 | { _M_h.reserve(__n); } |
1133 | |
1134 | template<typename _Key1, typename _Tp1, typename _Hash1, typename _Pred1, |
1135 | typename _Alloc1> |
1136 | friend bool |
1137 | operator==(const unordered_map<_Key1, _Tp1, _Hash1, _Pred1, _Alloc1>&, |
1138 | const unordered_map<_Key1, _Tp1, _Hash1, _Pred1, _Alloc1>&); |
1139 | }; |
1140 | |
1141 | #if __cpp_deduction_guides >= 201606 |
1142 | |
1143 | template<typename _InputIterator, |
1144 | typename _Hash = hash<__iter_key_t<_InputIterator>>, |
1145 | typename _Pred = equal_to<__iter_key_t<_InputIterator>>, |
1146 | typename _Allocator = allocator<__iter_to_alloc_t<_InputIterator>>, |
1147 | typename = _RequireInputIter<_InputIterator>, |
1148 | typename = _RequireNotAllocatorOrIntegral<_Hash>, |
1149 | typename = _RequireNotAllocator<_Pred>, |
1150 | typename = _RequireAllocator<_Allocator>> |
1151 | unordered_map(_InputIterator, _InputIterator, |
1152 | typename unordered_map<int, int>::size_type = {}, |
1153 | _Hash = _Hash(), _Pred = _Pred(), _Allocator = _Allocator()) |
1154 | -> unordered_map<__iter_key_t<_InputIterator>, |
1155 | __iter_val_t<_InputIterator>, |
1156 | _Hash, _Pred, _Allocator>; |
1157 | |
1158 | template<typename _Key, typename _Tp, typename _Hash = hash<_Key>, |
1159 | typename _Pred = equal_to<_Key>, |
1160 | typename _Allocator = allocator<pair<const _Key, _Tp>>, |
1161 | typename = _RequireNotAllocatorOrIntegral<_Hash>, |
1162 | typename = _RequireNotAllocator<_Pred>, |
1163 | typename = _RequireAllocator<_Allocator>> |
1164 | unordered_map(initializer_list<pair<_Key, _Tp>>, |
1165 | typename unordered_map<int, int>::size_type = {}, |
1166 | _Hash = _Hash(), _Pred = _Pred(), _Allocator = _Allocator()) |
1167 | -> unordered_map<_Key, _Tp, _Hash, _Pred, _Allocator>; |
1168 | |
1169 | template<typename _InputIterator, typename _Allocator, |
1170 | typename = _RequireInputIter<_InputIterator>, |
1171 | typename = _RequireAllocator<_Allocator>> |
1172 | unordered_map(_InputIterator, _InputIterator, |
1173 | typename unordered_map<int, int>::size_type, _Allocator) |
1174 | -> unordered_map<__iter_key_t<_InputIterator>, |
1175 | __iter_val_t<_InputIterator>, |
1176 | hash<__iter_key_t<_InputIterator>>, |
1177 | equal_to<__iter_key_t<_InputIterator>>, |
1178 | _Allocator>; |
1179 | |
1180 | template<typename _InputIterator, typename _Allocator, |
1181 | typename = _RequireInputIter<_InputIterator>, |
1182 | typename = _RequireAllocator<_Allocator>> |
1183 | unordered_map(_InputIterator, _InputIterator, _Allocator) |
1184 | -> unordered_map<__iter_key_t<_InputIterator>, |
1185 | __iter_val_t<_InputIterator>, |
1186 | hash<__iter_key_t<_InputIterator>>, |
1187 | equal_to<__iter_key_t<_InputIterator>>, |
1188 | _Allocator>; |
1189 | |
1190 | template<typename _InputIterator, typename _Hash, typename _Allocator, |
1191 | typename = _RequireInputIter<_InputIterator>, |
1192 | typename = _RequireNotAllocatorOrIntegral<_Hash>, |
1193 | typename = _RequireAllocator<_Allocator>> |
1194 | unordered_map(_InputIterator, _InputIterator, |
1195 | typename unordered_map<int, int>::size_type, |
1196 | _Hash, _Allocator) |
1197 | -> unordered_map<__iter_key_t<_InputIterator>, |
1198 | __iter_val_t<_InputIterator>, _Hash, |
1199 | equal_to<__iter_key_t<_InputIterator>>, _Allocator>; |
1200 | |
1201 | template<typename _Key, typename _Tp, typename _Allocator, |
1202 | typename = _RequireAllocator<_Allocator>> |
1203 | unordered_map(initializer_list<pair<_Key, _Tp>>, |
1204 | typename unordered_map<int, int>::size_type, |
1205 | _Allocator) |
1206 | -> unordered_map<_Key, _Tp, hash<_Key>, equal_to<_Key>, _Allocator>; |
1207 | |
1208 | template<typename _Key, typename _Tp, typename _Allocator, |
1209 | typename = _RequireAllocator<_Allocator>> |
1210 | unordered_map(initializer_list<pair<_Key, _Tp>>, _Allocator) |
1211 | -> unordered_map<_Key, _Tp, hash<_Key>, equal_to<_Key>, _Allocator>; |
1212 | |
1213 | template<typename _Key, typename _Tp, typename _Hash, typename _Allocator, |
1214 | typename = _RequireNotAllocatorOrIntegral<_Hash>, |
1215 | typename = _RequireAllocator<_Allocator>> |
1216 | unordered_map(initializer_list<pair<_Key, _Tp>>, |
1217 | typename unordered_map<int, int>::size_type, |
1218 | _Hash, _Allocator) |
1219 | -> unordered_map<_Key, _Tp, _Hash, equal_to<_Key>, _Allocator>; |
1220 | |
1221 | #endif |
1222 | |
1223 | /** |
1224 | * @brief A standard container composed of equivalent keys |
1225 | * (possibly containing multiple of each key value) that associates |
1226 | * values of another type with the keys. |
1227 | * |
1228 | * @ingroup unordered_associative_containers |
1229 | * |
1230 | * @tparam _Key Type of key objects. |
1231 | * @tparam _Tp Type of mapped objects. |
1232 | * @tparam _Hash Hashing function object type, defaults to hash<_Value>. |
1233 | * @tparam _Pred Predicate function object type, defaults |
1234 | * to equal_to<_Value>. |
1235 | * @tparam _Alloc Allocator type, defaults to |
1236 | * std::allocator<std::pair<const _Key, _Tp>>. |
1237 | * |
1238 | * Meets the requirements of a <a href="tables.html#65">container</a>, and |
1239 | * <a href="tables.html#xx">unordered associative container</a> |
1240 | * |
1241 | * The resulting value type of the container is std::pair<const _Key, _Tp>. |
1242 | * |
1243 | * Base is _Hashtable, dispatched at compile time via template |
1244 | * alias __ummap_hashtable. |
1245 | */ |
1246 | template<typename _Key, typename _Tp, |
1247 | typename _Hash = hash<_Key>, |
1248 | typename _Pred = equal_to<_Key>, |
1249 | typename _Alloc = allocator<std::pair<const _Key, _Tp>>> |
1250 | class unordered_multimap |
1251 | { |
1252 | typedef __ummap_hashtable<_Key, _Tp, _Hash, _Pred, _Alloc> _Hashtable; |
1253 | _Hashtable _M_h; |
1254 | |
1255 | public: |
1256 | // typedefs: |
1257 | //@{ |
1258 | /// Public typedefs. |
1259 | typedef typename _Hashtable::key_type key_type; |
1260 | typedef typename _Hashtable::value_type value_type; |
1261 | typedef typename _Hashtable::mapped_type mapped_type; |
1262 | typedef typename _Hashtable::hasher hasher; |
1263 | typedef typename _Hashtable::key_equal key_equal; |
1264 | typedef typename _Hashtable::allocator_type allocator_type; |
1265 | //@} |
1266 | |
1267 | //@{ |
1268 | /// Iterator-related typedefs. |
1269 | typedef typename _Hashtable::pointer pointer; |
1270 | typedef typename _Hashtable::const_pointer const_pointer; |
1271 | typedef typename _Hashtable::reference reference; |
1272 | typedef typename _Hashtable::const_reference const_reference; |
1273 | typedef typename _Hashtable::iterator iterator; |
1274 | typedef typename _Hashtable::const_iterator const_iterator; |
1275 | typedef typename _Hashtable::local_iterator local_iterator; |
1276 | typedef typename _Hashtable::const_local_iterator const_local_iterator; |
1277 | typedef typename _Hashtable::size_type size_type; |
1278 | typedef typename _Hashtable::difference_type difference_type; |
1279 | //@} |
1280 | |
1281 | #if __cplusplus > 201402L |
1282 | using node_type = typename _Hashtable::node_type; |
1283 | #endif |
1284 | |
1285 | //construct/destroy/copy |
1286 | |
1287 | /// Default constructor. |
1288 | unordered_multimap() = default; |
1289 | |
1290 | /** |
1291 | * @brief Default constructor creates no elements. |
1292 | * @param __n Mnimal initial number of buckets. |
1293 | * @param __hf A hash functor. |
1294 | * @param __eql A key equality functor. |
1295 | * @param __a An allocator object. |
1296 | */ |
1297 | explicit |
1298 | unordered_multimap(size_type __n, |
1299 | const hasher& __hf = hasher(), |
1300 | const key_equal& __eql = key_equal(), |
1301 | const allocator_type& __a = allocator_type()) |
1302 | : _M_h(__n, __hf, __eql, __a) |
1303 | { } |
1304 | |
1305 | /** |
1306 | * @brief Builds an %unordered_multimap from a range. |
1307 | * @param __first An input iterator. |
1308 | * @param __last An input iterator. |
1309 | * @param __n Minimal initial number of buckets. |
1310 | * @param __hf A hash functor. |
1311 | * @param __eql A key equality functor. |
1312 | * @param __a An allocator object. |
1313 | * |
1314 | * Create an %unordered_multimap consisting of copies of the elements |
1315 | * from [__first,__last). This is linear in N (where N is |
1316 | * distance(__first,__last)). |
1317 | */ |
1318 | template<typename _InputIterator> |
1319 | unordered_multimap(_InputIterator __first, _InputIterator __last, |
1320 | size_type __n = 0, |
1321 | const hasher& __hf = hasher(), |
1322 | const key_equal& __eql = key_equal(), |
1323 | const allocator_type& __a = allocator_type()) |
1324 | : _M_h(__first, __last, __n, __hf, __eql, __a) |
1325 | { } |
1326 | |
1327 | /// Copy constructor. |
1328 | unordered_multimap(const unordered_multimap&) = default; |
1329 | |
1330 | /// Move constructor. |
1331 | unordered_multimap(unordered_multimap&&) = default; |
1332 | |
1333 | /** |
1334 | * @brief Creates an %unordered_multimap with no elements. |
1335 | * @param __a An allocator object. |
1336 | */ |
1337 | explicit |
1338 | unordered_multimap(const allocator_type& __a) |
1339 | : _M_h(__a) |
1340 | { } |
1341 | |
1342 | /* |
1343 | * @brief Copy constructor with allocator argument. |
1344 | * @param __uset Input %unordered_multimap to copy. |
1345 | * @param __a An allocator object. |
1346 | */ |
1347 | unordered_multimap(const unordered_multimap& __ummap, |
1348 | const allocator_type& __a) |
1349 | : _M_h(__ummap._M_h, __a) |
1350 | { } |
1351 | |
1352 | /* |
1353 | * @brief Move constructor with allocator argument. |
1354 | * @param __uset Input %unordered_multimap to move. |
1355 | * @param __a An allocator object. |
1356 | */ |
1357 | unordered_multimap(unordered_multimap&& __ummap, |
1358 | const allocator_type& __a) |
1359 | : _M_h(std::move(__ummap._M_h), __a) |
1360 | { } |
1361 | |
1362 | /** |
1363 | * @brief Builds an %unordered_multimap from an initializer_list. |
1364 | * @param __l An initializer_list. |
1365 | * @param __n Minimal initial number of buckets. |
1366 | * @param __hf A hash functor. |
1367 | * @param __eql A key equality functor. |
1368 | * @param __a An allocator object. |
1369 | * |
1370 | * Create an %unordered_multimap consisting of copies of the elements in |
1371 | * the list. This is linear in N (where N is @a __l.size()). |
1372 | */ |
1373 | unordered_multimap(initializer_list<value_type> __l, |
1374 | size_type __n = 0, |
1375 | const hasher& __hf = hasher(), |
1376 | const key_equal& __eql = key_equal(), |
1377 | const allocator_type& __a = allocator_type()) |
1378 | : _M_h(__l, __n, __hf, __eql, __a) |
1379 | { } |
1380 | |
1381 | unordered_multimap(size_type __n, const allocator_type& __a) |
1382 | : unordered_multimap(__n, hasher(), key_equal(), __a) |
1383 | { } |
1384 | |
1385 | unordered_multimap(size_type __n, const hasher& __hf, |
1386 | const allocator_type& __a) |
1387 | : unordered_multimap(__n, __hf, key_equal(), __a) |
1388 | { } |
1389 | |
1390 | template<typename _InputIterator> |
1391 | unordered_multimap(_InputIterator __first, _InputIterator __last, |
1392 | size_type __n, |
1393 | const allocator_type& __a) |
1394 | : unordered_multimap(__first, __last, __n, hasher(), key_equal(), __a) |
1395 | { } |
1396 | |
1397 | template<typename _InputIterator> |
1398 | unordered_multimap(_InputIterator __first, _InputIterator __last, |
1399 | size_type __n, const hasher& __hf, |
1400 | const allocator_type& __a) |
1401 | : unordered_multimap(__first, __last, __n, __hf, key_equal(), __a) |
1402 | { } |
1403 | |
1404 | unordered_multimap(initializer_list<value_type> __l, |
1405 | size_type __n, |
1406 | const allocator_type& __a) |
1407 | : unordered_multimap(__l, __n, hasher(), key_equal(), __a) |
1408 | { } |
1409 | |
1410 | unordered_multimap(initializer_list<value_type> __l, |
1411 | size_type __n, const hasher& __hf, |
1412 | const allocator_type& __a) |
1413 | : unordered_multimap(__l, __n, __hf, key_equal(), __a) |
1414 | { } |
1415 | |
1416 | /// Copy assignment operator. |
1417 | unordered_multimap& |
1418 | operator=(const unordered_multimap&) = default; |
1419 | |
1420 | /// Move assignment operator. |
1421 | unordered_multimap& |
1422 | operator=(unordered_multimap&&) = default; |
1423 | |
1424 | /** |
1425 | * @brief %Unordered_multimap list assignment operator. |
1426 | * @param __l An initializer_list. |
1427 | * |
1428 | * This function fills an %unordered_multimap with copies of the |
1429 | * elements in the initializer list @a __l. |
1430 | * |
1431 | * Note that the assignment completely changes the %unordered_multimap |
1432 | * and that the resulting %unordered_multimap's size is the same as the |
1433 | * number of elements assigned. |
1434 | */ |
1435 | unordered_multimap& |
1436 | operator=(initializer_list<value_type> __l) |
1437 | { |
1438 | _M_h = __l; |
1439 | return *this; |
1440 | } |
1441 | |
1442 | /// Returns the allocator object used by the %unordered_multimap. |
1443 | allocator_type |
1444 | get_allocator() const noexcept |
1445 | { return _M_h.get_allocator(); } |
1446 | |
1447 | // size and capacity: |
1448 | |
1449 | /// Returns true if the %unordered_multimap is empty. |
1450 | _GLIBCXX_NODISCARD bool |
1451 | empty() const noexcept |
1452 | { return _M_h.empty(); } |
1453 | |
1454 | /// Returns the size of the %unordered_multimap. |
1455 | size_type |
1456 | size() const noexcept |
1457 | { return _M_h.size(); } |
1458 | |
1459 | /// Returns the maximum size of the %unordered_multimap. |
1460 | size_type |
1461 | max_size() const noexcept |
1462 | { return _M_h.max_size(); } |
1463 | |
1464 | // iterators. |
1465 | |
1466 | /** |
1467 | * Returns a read/write iterator that points to the first element in the |
1468 | * %unordered_multimap. |
1469 | */ |
1470 | iterator |
1471 | begin() noexcept |
1472 | { return _M_h.begin(); } |
1473 | |
1474 | //@{ |
1475 | /** |
1476 | * Returns a read-only (constant) iterator that points to the first |
1477 | * element in the %unordered_multimap. |
1478 | */ |
1479 | const_iterator |
1480 | begin() const noexcept |
1481 | { return _M_h.begin(); } |
1482 | |
1483 | const_iterator |
1484 | cbegin() const noexcept |
1485 | { return _M_h.begin(); } |
1486 | //@} |
1487 | |
1488 | /** |
1489 | * Returns a read/write iterator that points one past the last element in |
1490 | * the %unordered_multimap. |
1491 | */ |
1492 | iterator |
1493 | end() noexcept |
1494 | { return _M_h.end(); } |
1495 | |
1496 | //@{ |
1497 | /** |
1498 | * Returns a read-only (constant) iterator that points one past the last |
1499 | * element in the %unordered_multimap. |
1500 | */ |
1501 | const_iterator |
1502 | end() const noexcept |
1503 | { return _M_h.end(); } |
1504 | |
1505 | const_iterator |
1506 | cend() const noexcept |
1507 | { return _M_h.end(); } |
1508 | //@} |
1509 | |
1510 | // modifiers. |
1511 | |
1512 | /** |
1513 | * @brief Attempts to build and insert a std::pair into the |
1514 | * %unordered_multimap. |
1515 | * |
1516 | * @param __args Arguments used to generate a new pair instance (see |
1517 | * std::piecewise_contruct for passing arguments to each |
1518 | * part of the pair constructor). |
1519 | * |
1520 | * @return An iterator that points to the inserted pair. |
1521 | * |
1522 | * This function attempts to build and insert a (key, value) %pair into |
1523 | * the %unordered_multimap. |
1524 | * |
1525 | * Insertion requires amortized constant time. |
1526 | */ |
1527 | template<typename... _Args> |
1528 | iterator |
1529 | emplace(_Args&&... __args) |
1530 | { return _M_h.emplace(std::forward<_Args>(__args)...); } |
1531 | |
1532 | /** |
1533 | * @brief Attempts to build and insert a std::pair into the |
1534 | * %unordered_multimap. |
1535 | * |
1536 | * @param __pos An iterator that serves as a hint as to where the pair |
1537 | * should be inserted. |
1538 | * @param __args Arguments used to generate a new pair instance (see |
1539 | * std::piecewise_contruct for passing arguments to each |
1540 | * part of the pair constructor). |
1541 | * @return An iterator that points to the element with key of the |
1542 | * std::pair built from @a __args. |
1543 | * |
1544 | * Note that the first parameter is only a hint and can potentially |
1545 | * improve the performance of the insertion process. A bad hint would |
1546 | * cause no gains in efficiency. |
1547 | * |
1548 | * See |
1549 | * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints |
1550 | * for more on @a hinting. |
1551 | * |
1552 | * Insertion requires amortized constant time. |
1553 | */ |
1554 | template<typename... _Args> |
1555 | iterator |
1556 | emplace_hint(const_iterator __pos, _Args&&... __args) |
1557 | { return _M_h.emplace_hint(__pos, std::forward<_Args>(__args)...); } |
1558 | |
1559 | //@{ |
1560 | /** |
1561 | * @brief Inserts a std::pair into the %unordered_multimap. |
1562 | * @param __x Pair to be inserted (see std::make_pair for easy |
1563 | * creation of pairs). |
1564 | * |
1565 | * @return An iterator that points to the inserted pair. |
1566 | * |
1567 | * Insertion requires amortized constant time. |
1568 | */ |
1569 | iterator |
1570 | insert(const value_type& __x) |
1571 | { return _M_h.insert(__x); } |
1572 | |
1573 | iterator |
1574 | insert(value_type&& __x) |
1575 | { return _M_h.insert(std::move(__x)); } |
1576 | |
1577 | template<typename _Pair> |
1578 | __enable_if_t<is_constructible<value_type, _Pair&&>::value, iterator> |
1579 | insert(_Pair&& __x) |
1580 | { return _M_h.emplace(std::forward<_Pair>(__x)); } |
1581 | //@} |
1582 | |
1583 | //@{ |
1584 | /** |
1585 | * @brief Inserts a std::pair into the %unordered_multimap. |
1586 | * @param __hint An iterator that serves as a hint as to where the |
1587 | * pair should be inserted. |
1588 | * @param __x Pair to be inserted (see std::make_pair for easy creation |
1589 | * of pairs). |
1590 | * @return An iterator that points to the element with key of |
1591 | * @a __x (may or may not be the %pair passed in). |
1592 | * |
1593 | * Note that the first parameter is only a hint and can potentially |
1594 | * improve the performance of the insertion process. A bad hint would |
1595 | * cause no gains in efficiency. |
1596 | * |
1597 | * See |
1598 | * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints |
1599 | * for more on @a hinting. |
1600 | * |
1601 | * Insertion requires amortized constant time. |
1602 | */ |
1603 | iterator |
1604 | insert(const_iterator __hint, const value_type& __x) |
1605 | { return _M_h.insert(__hint, __x); } |
1606 | |
1607 | // _GLIBCXX_RESOLVE_LIB_DEFECTS |
1608 | // 2354. Unnecessary copying when inserting into maps with braced-init |
1609 | iterator |
1610 | insert(const_iterator __hint, value_type&& __x) |
1611 | { return _M_h.insert(__hint, std::move(__x)); } |
1612 | |
1613 | template<typename _Pair> |
1614 | __enable_if_t<is_constructible<value_type, _Pair&&>::value, iterator> |
1615 | insert(const_iterator __hint, _Pair&& __x) |
1616 | { return _M_h.emplace_hint(__hint, std::forward<_Pair>(__x)); } |
1617 | //@} |
1618 | |
1619 | /** |
1620 | * @brief A template function that attempts to insert a range of |
1621 | * elements. |
1622 | * @param __first Iterator pointing to the start of the range to be |
1623 | * inserted. |
1624 | * @param __last Iterator pointing to the end of the range. |
1625 | * |
1626 | * Complexity similar to that of the range constructor. |
1627 | */ |
1628 | template<typename _InputIterator> |
1629 | void |
1630 | insert(_InputIterator __first, _InputIterator __last) |
1631 | { _M_h.insert(__first, __last); } |
1632 | |
1633 | /** |
1634 | * @brief Attempts to insert a list of elements into the |
1635 | * %unordered_multimap. |
1636 | * @param __l A std::initializer_list<value_type> of elements |
1637 | * to be inserted. |
1638 | * |
1639 | * Complexity similar to that of the range constructor. |
1640 | */ |
1641 | void |
1642 | insert(initializer_list<value_type> __l) |
1643 | { _M_h.insert(__l); } |
1644 | |
1645 | #if __cplusplus > 201402L |
1646 | /// Extract a node. |
1647 | node_type |
1648 | (const_iterator __pos) |
1649 | { |
1650 | __glibcxx_assert(__pos != end()); |
1651 | return _M_h.extract(__pos); |
1652 | } |
1653 | |
1654 | /// Extract a node. |
1655 | node_type |
1656 | (const key_type& __key) |
1657 | { return _M_h.extract(__key); } |
1658 | |
1659 | /// Re-insert an extracted node. |
1660 | iterator |
1661 | insert(node_type&& __nh) |
1662 | { return _M_h._M_reinsert_node_multi(cend(), std::move(__nh)); } |
1663 | |
1664 | /// Re-insert an extracted node. |
1665 | iterator |
1666 | insert(const_iterator __hint, node_type&& __nh) |
1667 | { return _M_h._M_reinsert_node_multi(__hint, std::move(__nh)); } |
1668 | #endif // C++17 |
1669 | |
1670 | //@{ |
1671 | /** |
1672 | * @brief Erases an element from an %unordered_multimap. |
1673 | * @param __position An iterator pointing to the element to be erased. |
1674 | * @return An iterator pointing to the element immediately following |
1675 | * @a __position prior to the element being erased. If no such |
1676 | * element exists, end() is returned. |
1677 | * |
1678 | * This function erases an element, pointed to by the given iterator, |
1679 | * from an %unordered_multimap. |
1680 | * Note that this function only erases the element, and that if the |
1681 | * element is itself a pointer, the pointed-to memory is not touched in |
1682 | * any way. Managing the pointer is the user's responsibility. |
1683 | */ |
1684 | iterator |
1685 | erase(const_iterator __position) |
1686 | { return _M_h.erase(__position); } |
1687 | |
1688 | // LWG 2059. |
1689 | iterator |
1690 | erase(iterator __position) |
1691 | { return _M_h.erase(__position); } |
1692 | //@} |
1693 | |
1694 | /** |
1695 | * @brief Erases elements according to the provided key. |
1696 | * @param __x Key of elements to be erased. |
1697 | * @return The number of elements erased. |
1698 | * |
1699 | * This function erases all the elements located by the given key from |
1700 | * an %unordered_multimap. |
1701 | * Note that this function only erases the element, and that if the |
1702 | * element is itself a pointer, the pointed-to memory is not touched in |
1703 | * any way. Managing the pointer is the user's responsibility. |
1704 | */ |
1705 | size_type |
1706 | erase(const key_type& __x) |
1707 | { return _M_h.erase(__x); } |
1708 | |
1709 | /** |
1710 | * @brief Erases a [__first,__last) range of elements from an |
1711 | * %unordered_multimap. |
1712 | * @param __first Iterator pointing to the start of the range to be |
1713 | * erased. |
1714 | * @param __last Iterator pointing to the end of the range to |
1715 | * be erased. |
1716 | * @return The iterator @a __last. |
1717 | * |
1718 | * This function erases a sequence of elements from an |
1719 | * %unordered_multimap. |
1720 | * Note that this function only erases the elements, and that if |
1721 | * the element is itself a pointer, the pointed-to memory is not touched |
1722 | * in any way. Managing the pointer is the user's responsibility. |
1723 | */ |
1724 | iterator |
1725 | erase(const_iterator __first, const_iterator __last) |
1726 | { return _M_h.erase(__first, __last); } |
1727 | |
1728 | /** |
1729 | * Erases all elements in an %unordered_multimap. |
1730 | * Note that this function only erases the elements, and that if the |
1731 | * elements themselves are pointers, the pointed-to memory is not touched |
1732 | * in any way. Managing the pointer is the user's responsibility. |
1733 | */ |
1734 | void |
1735 | clear() noexcept |
1736 | { _M_h.clear(); } |
1737 | |
1738 | /** |
1739 | * @brief Swaps data with another %unordered_multimap. |
1740 | * @param __x An %unordered_multimap of the same element and allocator |
1741 | * types. |
1742 | * |
1743 | * This exchanges the elements between two %unordered_multimap in |
1744 | * constant time. |
1745 | * Note that the global std::swap() function is specialized such that |
1746 | * std::swap(m1,m2) will feed to this function. |
1747 | */ |
1748 | void |
1749 | swap(unordered_multimap& __x) |
1750 | noexcept( noexcept(_M_h.swap(__x._M_h)) ) |
1751 | { _M_h.swap(__x._M_h); } |
1752 | |
1753 | #if __cplusplus > 201402L |
1754 | template<typename, typename, typename> |
1755 | friend class std::_Hash_merge_helper; |
1756 | |
1757 | template<typename _H2, typename _P2> |
1758 | void |
1759 | merge(unordered_multimap<_Key, _Tp, _H2, _P2, _Alloc>& __source) |
1760 | { |
1761 | using _Merge_helper |
1762 | = _Hash_merge_helper<unordered_multimap, _H2, _P2>; |
1763 | _M_h._M_merge_multi(_Merge_helper::_S_get_table(__source)); |
1764 | } |
1765 | |
1766 | template<typename _H2, typename _P2> |
1767 | void |
1768 | merge(unordered_multimap<_Key, _Tp, _H2, _P2, _Alloc>&& __source) |
1769 | { merge(__source); } |
1770 | |
1771 | template<typename _H2, typename _P2> |
1772 | void |
1773 | merge(unordered_map<_Key, _Tp, _H2, _P2, _Alloc>& __source) |
1774 | { |
1775 | using _Merge_helper |
1776 | = _Hash_merge_helper<unordered_multimap, _H2, _P2>; |
1777 | _M_h._M_merge_multi(_Merge_helper::_S_get_table(__source)); |
1778 | } |
1779 | |
1780 | template<typename _H2, typename _P2> |
1781 | void |
1782 | merge(unordered_map<_Key, _Tp, _H2, _P2, _Alloc>&& __source) |
1783 | { merge(__source); } |
1784 | #endif // C++17 |
1785 | |
1786 | // observers. |
1787 | |
1788 | /// Returns the hash functor object with which the %unordered_multimap |
1789 | /// was constructed. |
1790 | hasher |
1791 | hash_function() const |
1792 | { return _M_h.hash_function(); } |
1793 | |
1794 | /// Returns the key comparison object with which the %unordered_multimap |
1795 | /// was constructed. |
1796 | key_equal |
1797 | key_eq() const |
1798 | { return _M_h.key_eq(); } |
1799 | |
1800 | // lookup. |
1801 | |
1802 | //@{ |
1803 | /** |
1804 | * @brief Tries to locate an element in an %unordered_multimap. |
1805 | * @param __x Key to be located. |
1806 | * @return Iterator pointing to sought-after element, or end() if not |
1807 | * found. |
1808 | * |
1809 | * This function takes a key and tries to locate the element with which |
1810 | * the key matches. If successful the function returns an iterator |
1811 | * pointing to the sought after element. If unsuccessful it returns the |
1812 | * past-the-end ( @c end() ) iterator. |
1813 | */ |
1814 | iterator |
1815 | find(const key_type& __x) |
1816 | { return _M_h.find(__x); } |
1817 | |
1818 | const_iterator |
1819 | find(const key_type& __x) const |
1820 | { return _M_h.find(__x); } |
1821 | //@} |
1822 | |
1823 | /** |
1824 | * @brief Finds the number of elements. |
1825 | * @param __x Key to count. |
1826 | * @return Number of elements with specified key. |
1827 | */ |
1828 | size_type |
1829 | count(const key_type& __x) const |
1830 | { return _M_h.count(__x); } |
1831 | |
1832 | #if __cplusplus > 201703L |
1833 | /** |
1834 | * @brief Finds whether an element with the given key exists. |
1835 | * @param __x Key of elements to be located. |
1836 | * @return True if there is any element with the specified key. |
1837 | */ |
1838 | bool |
1839 | contains(const key_type& __x) const |
1840 | { return _M_h.find(__x) != _M_h.end(); } |
1841 | #endif |
1842 | |
1843 | //@{ |
1844 | /** |
1845 | * @brief Finds a subsequence matching given key. |
1846 | * @param __x Key to be located. |
1847 | * @return Pair of iterators that possibly points to the subsequence |
1848 | * matching given key. |
1849 | */ |
1850 | std::pair<iterator, iterator> |
1851 | equal_range(const key_type& __x) |
1852 | { return _M_h.equal_range(__x); } |
1853 | |
1854 | std::pair<const_iterator, const_iterator> |
1855 | equal_range(const key_type& __x) const |
1856 | { return _M_h.equal_range(__x); } |
1857 | //@} |
1858 | |
1859 | // bucket interface. |
1860 | |
1861 | /// Returns the number of buckets of the %unordered_multimap. |
1862 | size_type |
1863 | bucket_count() const noexcept |
1864 | { return _M_h.bucket_count(); } |
1865 | |
1866 | /// Returns the maximum number of buckets of the %unordered_multimap. |
1867 | size_type |
1868 | max_bucket_count() const noexcept |
1869 | { return _M_h.max_bucket_count(); } |
1870 | |
1871 | /* |
1872 | * @brief Returns the number of elements in a given bucket. |
1873 | * @param __n A bucket index. |
1874 | * @return The number of elements in the bucket. |
1875 | */ |
1876 | size_type |
1877 | bucket_size(size_type __n) const |
1878 | { return _M_h.bucket_size(__n); } |
1879 | |
1880 | /* |
1881 | * @brief Returns the bucket index of a given element. |
1882 | * @param __key A key instance. |
1883 | * @return The key bucket index. |
1884 | */ |
1885 | size_type |
1886 | bucket(const key_type& __key) const |
1887 | { return _M_h.bucket(__key); } |
1888 | |
1889 | /** |
1890 | * @brief Returns a read/write iterator pointing to the first bucket |
1891 | * element. |
1892 | * @param __n The bucket index. |
1893 | * @return A read/write local iterator. |
1894 | */ |
1895 | local_iterator |
1896 | begin(size_type __n) |
1897 | { return _M_h.begin(__n); } |
1898 | |
1899 | //@{ |
1900 | /** |
1901 | * @brief Returns a read-only (constant) iterator pointing to the first |
1902 | * bucket element. |
1903 | * @param __n The bucket index. |
1904 | * @return A read-only local iterator. |
1905 | */ |
1906 | const_local_iterator |
1907 | begin(size_type __n) const |
1908 | { return _M_h.begin(__n); } |
1909 | |
1910 | const_local_iterator |
1911 | cbegin(size_type __n) const |
1912 | { return _M_h.cbegin(__n); } |
1913 | //@} |
1914 | |
1915 | /** |
1916 | * @brief Returns a read/write iterator pointing to one past the last |
1917 | * bucket elements. |
1918 | * @param __n The bucket index. |
1919 | * @return A read/write local iterator. |
1920 | */ |
1921 | local_iterator |
1922 | end(size_type __n) |
1923 | { return _M_h.end(__n); } |
1924 | |
1925 | //@{ |
1926 | /** |
1927 | * @brief Returns a read-only (constant) iterator pointing to one past |
1928 | * the last bucket elements. |
1929 | * @param __n The bucket index. |
1930 | * @return A read-only local iterator. |
1931 | */ |
1932 | const_local_iterator |
1933 | end(size_type __n) const |
1934 | { return _M_h.end(__n); } |
1935 | |
1936 | const_local_iterator |
1937 | cend(size_type __n) const |
1938 | { return _M_h.cend(__n); } |
1939 | //@} |
1940 | |
1941 | // hash policy. |
1942 | |
1943 | /// Returns the average number of elements per bucket. |
1944 | float |
1945 | load_factor() const noexcept |
1946 | { return _M_h.load_factor(); } |
1947 | |
1948 | /// Returns a positive number that the %unordered_multimap tries to keep |
1949 | /// the load factor less than or equal to. |
1950 | float |
1951 | max_load_factor() const noexcept |
1952 | { return _M_h.max_load_factor(); } |
1953 | |
1954 | /** |
1955 | * @brief Change the %unordered_multimap maximum load factor. |
1956 | * @param __z The new maximum load factor. |
1957 | */ |
1958 | void |
1959 | max_load_factor(float __z) |
1960 | { _M_h.max_load_factor(__z); } |
1961 | |
1962 | /** |
1963 | * @brief May rehash the %unordered_multimap. |
1964 | * @param __n The new number of buckets. |
1965 | * |
1966 | * Rehash will occur only if the new number of buckets respect the |
1967 | * %unordered_multimap maximum load factor. |
1968 | */ |
1969 | void |
1970 | rehash(size_type __n) |
1971 | { _M_h.rehash(__n); } |
1972 | |
1973 | /** |
1974 | * @brief Prepare the %unordered_multimap for a specified number of |
1975 | * elements. |
1976 | * @param __n Number of elements required. |
1977 | * |
1978 | * Same as rehash(ceil(n / max_load_factor())). |
1979 | */ |
1980 | void |
1981 | reserve(size_type __n) |
1982 | { _M_h.reserve(__n); } |
1983 | |
1984 | template<typename _Key1, typename _Tp1, typename _Hash1, typename _Pred1, |
1985 | typename _Alloc1> |
1986 | friend bool |
1987 | operator==(const unordered_multimap<_Key1, _Tp1, |
1988 | _Hash1, _Pred1, _Alloc1>&, |
1989 | const unordered_multimap<_Key1, _Tp1, |
1990 | _Hash1, _Pred1, _Alloc1>&); |
1991 | }; |
1992 | |
1993 | #if __cpp_deduction_guides >= 201606 |
1994 | |
1995 | template<typename _InputIterator, |
1996 | typename _Hash = hash<__iter_key_t<_InputIterator>>, |
1997 | typename _Pred = equal_to<__iter_key_t<_InputIterator>>, |
1998 | typename _Allocator = allocator<__iter_to_alloc_t<_InputIterator>>, |
1999 | typename = _RequireInputIter<_InputIterator>, |
2000 | typename = _RequireNotAllocatorOrIntegral<_Hash>, |
2001 | typename = _RequireNotAllocator<_Pred>, |
2002 | typename = _RequireAllocator<_Allocator>> |
2003 | unordered_multimap(_InputIterator, _InputIterator, |
2004 | unordered_multimap<int, int>::size_type = {}, |
2005 | _Hash = _Hash(), _Pred = _Pred(), |
2006 | _Allocator = _Allocator()) |
2007 | -> unordered_multimap<__iter_key_t<_InputIterator>, |
2008 | __iter_val_t<_InputIterator>, _Hash, _Pred, |
2009 | _Allocator>; |
2010 | |
2011 | template<typename _Key, typename _Tp, typename _Hash = hash<_Key>, |
2012 | typename _Pred = equal_to<_Key>, |
2013 | typename _Allocator = allocator<pair<const _Key, _Tp>>, |
2014 | typename = _RequireNotAllocatorOrIntegral<_Hash>, |
2015 | typename = _RequireNotAllocator<_Pred>, |
2016 | typename = _RequireAllocator<_Allocator>> |
2017 | unordered_multimap(initializer_list<pair<_Key, _Tp>>, |
2018 | unordered_multimap<int, int>::size_type = {}, |
2019 | _Hash = _Hash(), _Pred = _Pred(), |
2020 | _Allocator = _Allocator()) |
2021 | -> unordered_multimap<_Key, _Tp, _Hash, _Pred, _Allocator>; |
2022 | |
2023 | template<typename _InputIterator, typename _Allocator, |
2024 | typename = _RequireInputIter<_InputIterator>, |
2025 | typename = _RequireAllocator<_Allocator>> |
2026 | unordered_multimap(_InputIterator, _InputIterator, |
2027 | unordered_multimap<int, int>::size_type, _Allocator) |
2028 | -> unordered_multimap<__iter_key_t<_InputIterator>, |
2029 | __iter_val_t<_InputIterator>, |
2030 | hash<__iter_key_t<_InputIterator>>, |
2031 | equal_to<__iter_key_t<_InputIterator>>, _Allocator>; |
2032 | |
2033 | template<typename _InputIterator, typename _Allocator, |
2034 | typename = _RequireInputIter<_InputIterator>, |
2035 | typename = _RequireAllocator<_Allocator>> |
2036 | unordered_multimap(_InputIterator, _InputIterator, _Allocator) |
2037 | -> unordered_multimap<__iter_key_t<_InputIterator>, |
2038 | __iter_val_t<_InputIterator>, |
2039 | hash<__iter_key_t<_InputIterator>>, |
2040 | equal_to<__iter_key_t<_InputIterator>>, _Allocator>; |
2041 | |
2042 | template<typename _InputIterator, typename _Hash, typename _Allocator, |
2043 | typename = _RequireInputIter<_InputIterator>, |
2044 | typename = _RequireNotAllocatorOrIntegral<_Hash>, |
2045 | typename = _RequireAllocator<_Allocator>> |
2046 | unordered_multimap(_InputIterator, _InputIterator, |
2047 | unordered_multimap<int, int>::size_type, _Hash, |
2048 | _Allocator) |
2049 | -> unordered_multimap<__iter_key_t<_InputIterator>, |
2050 | __iter_val_t<_InputIterator>, _Hash, |
2051 | equal_to<__iter_key_t<_InputIterator>>, _Allocator>; |
2052 | |
2053 | template<typename _Key, typename _Tp, typename _Allocator, |
2054 | typename = _RequireAllocator<_Allocator>> |
2055 | unordered_multimap(initializer_list<pair<_Key, _Tp>>, |
2056 | unordered_multimap<int, int>::size_type, |
2057 | _Allocator) |
2058 | -> unordered_multimap<_Key, _Tp, hash<_Key>, equal_to<_Key>, _Allocator>; |
2059 | |
2060 | template<typename _Key, typename _Tp, typename _Allocator, |
2061 | typename = _RequireAllocator<_Allocator>> |
2062 | unordered_multimap(initializer_list<pair<_Key, _Tp>>, _Allocator) |
2063 | -> unordered_multimap<_Key, _Tp, hash<_Key>, equal_to<_Key>, _Allocator>; |
2064 | |
2065 | template<typename _Key, typename _Tp, typename _Hash, typename _Allocator, |
2066 | typename = _RequireNotAllocatorOrIntegral<_Hash>, |
2067 | typename = _RequireAllocator<_Allocator>> |
2068 | unordered_multimap(initializer_list<pair<_Key, _Tp>>, |
2069 | unordered_multimap<int, int>::size_type, |
2070 | _Hash, _Allocator) |
2071 | -> unordered_multimap<_Key, _Tp, _Hash, equal_to<_Key>, _Allocator>; |
2072 | |
2073 | #endif |
2074 | |
2075 | template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> |
2076 | inline void |
2077 | swap(unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x, |
2078 | unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) |
2079 | noexcept(noexcept(__x.swap(__y))) |
2080 | { __x.swap(__y); } |
2081 | |
2082 | template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> |
2083 | inline void |
2084 | swap(unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x, |
2085 | unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) |
2086 | noexcept(noexcept(__x.swap(__y))) |
2087 | { __x.swap(__y); } |
2088 | |
2089 | template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> |
2090 | inline bool |
2091 | operator==(const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x, |
2092 | const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) |
2093 | { return __x._M_h._M_equal(__y._M_h); } |
2094 | |
2095 | template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> |
2096 | inline bool |
2097 | operator!=(const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x, |
2098 | const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) |
2099 | { return !(__x == __y); } |
2100 | |
2101 | template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> |
2102 | inline bool |
2103 | operator==(const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x, |
2104 | const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) |
2105 | { return __x._M_h._M_equal(__y._M_h); } |
2106 | |
2107 | template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> |
2108 | inline bool |
2109 | operator!=(const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x, |
2110 | const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) |
2111 | { return !(__x == __y); } |
2112 | |
2113 | _GLIBCXX_END_NAMESPACE_CONTAINER |
2114 | |
2115 | #if __cplusplus > 201402L |
2116 | // Allow std::unordered_map access to internals of compatible maps. |
2117 | template<typename _Key, typename _Val, typename _Hash1, typename _Eq1, |
2118 | typename _Alloc, typename _Hash2, typename _Eq2> |
2119 | struct _Hash_merge_helper< |
2120 | _GLIBCXX_STD_C::unordered_map<_Key, _Val, _Hash1, _Eq1, _Alloc>, |
2121 | _Hash2, _Eq2> |
2122 | { |
2123 | private: |
2124 | template<typename... _Tp> |
2125 | using unordered_map = _GLIBCXX_STD_C::unordered_map<_Tp...>; |
2126 | template<typename... _Tp> |
2127 | using unordered_multimap = _GLIBCXX_STD_C::unordered_multimap<_Tp...>; |
2128 | |
2129 | friend unordered_map<_Key, _Val, _Hash1, _Eq1, _Alloc>; |
2130 | |
2131 | static auto& |
2132 | _S_get_table(unordered_map<_Key, _Val, _Hash2, _Eq2, _Alloc>& __map) |
2133 | { return __map._M_h; } |
2134 | |
2135 | static auto& |
2136 | _S_get_table(unordered_multimap<_Key, _Val, _Hash2, _Eq2, _Alloc>& __map) |
2137 | { return __map._M_h; } |
2138 | }; |
2139 | |
2140 | // Allow std::unordered_multimap access to internals of compatible maps. |
2141 | template<typename _Key, typename _Val, typename _Hash1, typename _Eq1, |
2142 | typename _Alloc, typename _Hash2, typename _Eq2> |
2143 | struct _Hash_merge_helper< |
2144 | _GLIBCXX_STD_C::unordered_multimap<_Key, _Val, _Hash1, _Eq1, _Alloc>, |
2145 | _Hash2, _Eq2> |
2146 | { |
2147 | private: |
2148 | template<typename... _Tp> |
2149 | using unordered_map = _GLIBCXX_STD_C::unordered_map<_Tp...>; |
2150 | template<typename... _Tp> |
2151 | using unordered_multimap = _GLIBCXX_STD_C::unordered_multimap<_Tp...>; |
2152 | |
2153 | friend unordered_multimap<_Key, _Val, _Hash1, _Eq1, _Alloc>; |
2154 | |
2155 | static auto& |
2156 | _S_get_table(unordered_map<_Key, _Val, _Hash2, _Eq2, _Alloc>& __map) |
2157 | { return __map._M_h; } |
2158 | |
2159 | static auto& |
2160 | _S_get_table(unordered_multimap<_Key, _Val, _Hash2, _Eq2, _Alloc>& __map) |
2161 | { return __map._M_h; } |
2162 | }; |
2163 | #endif // C++17 |
2164 | |
2165 | _GLIBCXX_END_NAMESPACE_VERSION |
2166 | } // namespace std |
2167 | |
2168 | #endif /* _UNORDERED_MAP_H */ |
2169 | |