1 | // Queue implementation -*- C++ -*- |
2 | |
3 | // Copyright (C) 2001-2021 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 bits/stl_queue.h |
52 | * This is an internal header file, included by other library headers. |
53 | * Do not attempt to use it directly. @headername{queue} |
54 | */ |
55 | |
56 | #ifndef _STL_QUEUE_H |
57 | #define _STL_QUEUE_H 1 |
58 | |
59 | #include <bits/concept_check.h> |
60 | #include <debug/debug.h> |
61 | #if __cplusplus >= 201103L |
62 | # include <bits/uses_allocator.h> |
63 | #endif |
64 | |
65 | namespace std _GLIBCXX_VISIBILITY(default) |
66 | { |
67 | _GLIBCXX_BEGIN_NAMESPACE_VERSION |
68 | |
69 | /** |
70 | * @brief A standard container giving FIFO behavior. |
71 | * |
72 | * @ingroup sequences |
73 | * |
74 | * @tparam _Tp Type of element. |
75 | * @tparam _Sequence Type of underlying sequence, defaults to deque<_Tp>. |
76 | * |
77 | * Meets many of the requirements of a |
78 | * <a href="tables.html#65">container</a>, |
79 | * but does not define anything to do with iterators. Very few of the |
80 | * other standard container interfaces are defined. |
81 | * |
82 | * This is not a true container, but an @e adaptor. It holds another |
83 | * container, and provides a wrapper interface to that container. The |
84 | * wrapper is what enforces strict first-in-first-out %queue behavior. |
85 | * |
86 | * The second template parameter defines the type of the underlying |
87 | * sequence/container. It defaults to std::deque, but it can be any type |
88 | * that supports @c front, @c back, @c push_back, and @c pop_front, |
89 | * such as std::list or an appropriate user-defined type. |
90 | * |
91 | * Members not found in @a normal containers are @c container_type, |
92 | * which is a typedef for the second Sequence parameter, and @c push and |
93 | * @c pop, which are standard %queue/FIFO operations. |
94 | */ |
95 | template<typename _Tp, typename _Sequence = deque<_Tp> > |
96 | class queue |
97 | { |
98 | #ifdef _GLIBCXX_CONCEPT_CHECKS |
99 | // concept requirements |
100 | typedef typename _Sequence::value_type _Sequence_value_type; |
101 | # if __cplusplus < 201103L |
102 | __glibcxx_class_requires(_Tp, _SGIAssignableConcept) |
103 | # endif |
104 | __glibcxx_class_requires(_Sequence, _FrontInsertionSequenceConcept) |
105 | __glibcxx_class_requires(_Sequence, _BackInsertionSequenceConcept) |
106 | __glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept) |
107 | #endif |
108 | |
109 | template<typename _Tp1, typename _Seq1> |
110 | friend bool |
111 | operator==(const queue<_Tp1, _Seq1>&, const queue<_Tp1, _Seq1>&); |
112 | |
113 | template<typename _Tp1, typename _Seq1> |
114 | friend bool |
115 | operator<(const queue<_Tp1, _Seq1>&, const queue<_Tp1, _Seq1>&); |
116 | |
117 | #if __cpp_lib_three_way_comparison |
118 | template<typename _Tp1, three_way_comparable _Seq1> |
119 | friend compare_three_way_result_t<_Seq1> |
120 | operator<=>(const queue<_Tp1, _Seq1>&, const queue<_Tp1, _Seq1>&); |
121 | #endif |
122 | |
123 | #if __cplusplus >= 201103L |
124 | template<typename _Alloc> |
125 | using _Uses = typename |
126 | enable_if<uses_allocator<_Sequence, _Alloc>::value>::type; |
127 | |
128 | #if __cplusplus >= 201703L |
129 | // _GLIBCXX_RESOLVE_LIB_DEFECTS |
130 | // 2566. Requirements on the first template parameter of container |
131 | // adaptors |
132 | static_assert(is_same<_Tp, typename _Sequence::value_type>::value, |
133 | "value_type must be the same as the underlying container" ); |
134 | #endif // C++17 |
135 | #endif // C++11 |
136 | |
137 | public: |
138 | typedef typename _Sequence::value_type value_type; |
139 | typedef typename _Sequence::reference reference; |
140 | typedef typename _Sequence::const_reference const_reference; |
141 | typedef typename _Sequence::size_type size_type; |
142 | typedef _Sequence container_type; |
143 | |
144 | protected: |
145 | /* Maintainers wondering why this isn't uglified as per style |
146 | * guidelines should note that this name is specified in the standard, |
147 | * C++98 [23.2.3.1]. |
148 | * (Why? Presumably for the same reason that it's protected instead |
149 | * of private: to allow derivation. But none of the other |
150 | * containers allow for derivation. Odd.) |
151 | */ |
152 | /// @c c is the underlying container. |
153 | _Sequence c; |
154 | |
155 | public: |
156 | /** |
157 | * @brief Default constructor creates no elements. |
158 | */ |
159 | #if __cplusplus < 201103L |
160 | explicit |
161 | queue(const _Sequence& __c = _Sequence()) |
162 | : c(__c) { } |
163 | #else |
164 | template<typename _Seq = _Sequence, typename _Requires = typename |
165 | enable_if<is_default_constructible<_Seq>::value>::type> |
166 | queue() |
167 | : c() { } |
168 | |
169 | explicit |
170 | queue(const _Sequence& __c) |
171 | : c(__c) { } |
172 | |
173 | explicit |
174 | queue(_Sequence&& __c) |
175 | : c(std::move(__c)) { } |
176 | |
177 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>> |
178 | explicit |
179 | queue(const _Alloc& __a) |
180 | : c(__a) { } |
181 | |
182 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>> |
183 | queue(const _Sequence& __c, const _Alloc& __a) |
184 | : c(__c, __a) { } |
185 | |
186 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>> |
187 | queue(_Sequence&& __c, const _Alloc& __a) |
188 | : c(std::move(__c), __a) { } |
189 | |
190 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>> |
191 | queue(const queue& __q, const _Alloc& __a) |
192 | : c(__q.c, __a) { } |
193 | |
194 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>> |
195 | queue(queue&& __q, const _Alloc& __a) |
196 | : c(std::move(__q.c), __a) { } |
197 | #endif |
198 | |
199 | /** |
200 | * Returns true if the %queue is empty. |
201 | */ |
202 | _GLIBCXX_NODISCARD bool |
203 | empty() const |
204 | { return c.empty(); } |
205 | |
206 | /** Returns the number of elements in the %queue. */ |
207 | size_type |
208 | size() const |
209 | { return c.size(); } |
210 | |
211 | /** |
212 | * Returns a read/write reference to the data at the first |
213 | * element of the %queue. |
214 | */ |
215 | reference |
216 | front() |
217 | { |
218 | __glibcxx_requires_nonempty(); |
219 | return c.front(); |
220 | } |
221 | |
222 | /** |
223 | * Returns a read-only (constant) reference to the data at the first |
224 | * element of the %queue. |
225 | */ |
226 | const_reference |
227 | front() const |
228 | { |
229 | __glibcxx_requires_nonempty(); |
230 | return c.front(); |
231 | } |
232 | |
233 | /** |
234 | * Returns a read/write reference to the data at the last |
235 | * element of the %queue. |
236 | */ |
237 | reference |
238 | back() |
239 | { |
240 | __glibcxx_requires_nonempty(); |
241 | return c.back(); |
242 | } |
243 | |
244 | /** |
245 | * Returns a read-only (constant) reference to the data at the last |
246 | * element of the %queue. |
247 | */ |
248 | const_reference |
249 | back() const |
250 | { |
251 | __glibcxx_requires_nonempty(); |
252 | return c.back(); |
253 | } |
254 | |
255 | /** |
256 | * @brief Add data to the end of the %queue. |
257 | * @param __x Data to be added. |
258 | * |
259 | * This is a typical %queue operation. The function creates an |
260 | * element at the end of the %queue and assigns the given data |
261 | * to it. The time complexity of the operation depends on the |
262 | * underlying sequence. |
263 | */ |
264 | void |
265 | push(const value_type& __x) |
266 | { c.push_back(__x); } |
267 | |
268 | #if __cplusplus >= 201103L |
269 | void |
270 | push(value_type&& __x) |
271 | { c.push_back(std::move(__x)); } |
272 | |
273 | #if __cplusplus > 201402L |
274 | template<typename... _Args> |
275 | decltype(auto) |
276 | emplace(_Args&&... __args) |
277 | { return c.emplace_back(std::forward<_Args>(__args)...); } |
278 | #else |
279 | template<typename... _Args> |
280 | void |
281 | emplace(_Args&&... __args) |
282 | { c.emplace_back(std::forward<_Args>(__args)...); } |
283 | #endif |
284 | #endif |
285 | |
286 | /** |
287 | * @brief Removes first element. |
288 | * |
289 | * This is a typical %queue operation. It shrinks the %queue by one. |
290 | * The time complexity of the operation depends on the underlying |
291 | * sequence. |
292 | * |
293 | * Note that no data is returned, and if the first element's |
294 | * data is needed, it should be retrieved before pop() is |
295 | * called. |
296 | */ |
297 | void |
298 | pop() |
299 | { |
300 | __glibcxx_requires_nonempty(); |
301 | c.pop_front(); |
302 | } |
303 | |
304 | #if __cplusplus >= 201103L |
305 | void |
306 | swap(queue& __q) |
307 | #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 |
308 | noexcept(__is_nothrow_swappable<_Sequence>::value) |
309 | #else |
310 | noexcept(__is_nothrow_swappable<_Tp>::value) |
311 | #endif |
312 | { |
313 | using std::swap; |
314 | swap(c, __q.c); |
315 | } |
316 | #endif // __cplusplus >= 201103L |
317 | }; |
318 | |
319 | #if __cpp_deduction_guides >= 201606 |
320 | template<typename _Container, |
321 | typename = _RequireNotAllocator<_Container>> |
322 | queue(_Container) -> queue<typename _Container::value_type, _Container>; |
323 | |
324 | template<typename _Container, typename _Allocator, |
325 | typename = _RequireNotAllocator<_Container>, |
326 | typename = _RequireAllocator<_Allocator>> |
327 | queue(_Container, _Allocator) |
328 | -> queue<typename _Container::value_type, _Container>; |
329 | #endif |
330 | |
331 | /** |
332 | * @brief Queue equality comparison. |
333 | * @param __x A %queue. |
334 | * @param __y A %queue of the same type as @a __x. |
335 | * @return True iff the size and elements of the queues are equal. |
336 | * |
337 | * This is an equivalence relation. Complexity and semantics depend on the |
338 | * underlying sequence type, but the expected rules are: this relation is |
339 | * linear in the size of the sequences, and queues are considered equivalent |
340 | * if their sequences compare equal. |
341 | */ |
342 | template<typename _Tp, typename _Seq> |
343 | inline bool |
344 | operator==(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y) |
345 | { return __x.c == __y.c; } |
346 | |
347 | /** |
348 | * @brief Queue ordering relation. |
349 | * @param __x A %queue. |
350 | * @param __y A %queue of the same type as @a x. |
351 | * @return True iff @a __x is lexicographically less than @a __y. |
352 | * |
353 | * This is an total ordering relation. Complexity and semantics |
354 | * depend on the underlying sequence type, but the expected rules |
355 | * are: this relation is linear in the size of the sequences, the |
356 | * elements must be comparable with @c <, and |
357 | * std::lexicographical_compare() is usually used to make the |
358 | * determination. |
359 | */ |
360 | template<typename _Tp, typename _Seq> |
361 | inline bool |
362 | operator<(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y) |
363 | { return __x.c < __y.c; } |
364 | |
365 | /// Based on operator== |
366 | template<typename _Tp, typename _Seq> |
367 | inline bool |
368 | operator!=(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y) |
369 | { return !(__x == __y); } |
370 | |
371 | /// Based on operator< |
372 | template<typename _Tp, typename _Seq> |
373 | inline bool |
374 | operator>(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y) |
375 | { return __y < __x; } |
376 | |
377 | /// Based on operator< |
378 | template<typename _Tp, typename _Seq> |
379 | inline bool |
380 | operator<=(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y) |
381 | { return !(__y < __x); } |
382 | |
383 | /// Based on operator< |
384 | template<typename _Tp, typename _Seq> |
385 | inline bool |
386 | operator>=(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y) |
387 | { return !(__x < __y); } |
388 | |
389 | #if __cpp_lib_three_way_comparison |
390 | template<typename _Tp, three_way_comparable _Seq> |
391 | inline compare_three_way_result_t<_Seq> |
392 | operator<=>(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y) |
393 | { return __x.c <=> __y.c; } |
394 | #endif |
395 | |
396 | #if __cplusplus >= 201103L |
397 | template<typename _Tp, typename _Seq> |
398 | inline |
399 | #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 |
400 | // Constrained free swap overload, see p0185r1 |
401 | typename enable_if<__is_swappable<_Seq>::value>::type |
402 | #else |
403 | void |
404 | #endif |
405 | swap(queue<_Tp, _Seq>& __x, queue<_Tp, _Seq>& __y) |
406 | noexcept(noexcept(__x.swap(__y))) |
407 | { __x.swap(__y); } |
408 | |
409 | template<typename _Tp, typename _Seq, typename _Alloc> |
410 | struct uses_allocator<queue<_Tp, _Seq>, _Alloc> |
411 | : public uses_allocator<_Seq, _Alloc>::type { }; |
412 | #endif // __cplusplus >= 201103L |
413 | |
414 | /** |
415 | * @brief A standard container automatically sorting its contents. |
416 | * |
417 | * @ingroup sequences |
418 | * |
419 | * @tparam _Tp Type of element. |
420 | * @tparam _Sequence Type of underlying sequence, defaults to vector<_Tp>. |
421 | * @tparam _Compare Comparison function object type, defaults to |
422 | * less<_Sequence::value_type>. |
423 | * |
424 | * This is not a true container, but an @e adaptor. It holds |
425 | * another container, and provides a wrapper interface to that |
426 | * container. The wrapper is what enforces priority-based sorting |
427 | * and %queue behavior. Very few of the standard container/sequence |
428 | * interface requirements are met (e.g., iterators). |
429 | * |
430 | * The second template parameter defines the type of the underlying |
431 | * sequence/container. It defaults to std::vector, but it can be |
432 | * any type that supports @c front(), @c push_back, @c pop_back, |
433 | * and random-access iterators, such as std::deque or an |
434 | * appropriate user-defined type. |
435 | * |
436 | * The third template parameter supplies the means of making |
437 | * priority comparisons. It defaults to @c less<value_type> but |
438 | * can be anything defining a strict weak ordering. |
439 | * |
440 | * Members not found in @a normal containers are @c container_type, |
441 | * which is a typedef for the second Sequence parameter, and @c |
442 | * push, @c pop, and @c top, which are standard %queue operations. |
443 | * |
444 | * @note No equality/comparison operators are provided for |
445 | * %priority_queue. |
446 | * |
447 | * @note Sorting of the elements takes place as they are added to, |
448 | * and removed from, the %priority_queue using the |
449 | * %priority_queue's member functions. If you access the elements |
450 | * by other means, and change their data such that the sorting |
451 | * order would be different, the %priority_queue will not re-sort |
452 | * the elements for you. (How could it know to do so?) |
453 | */ |
454 | template<typename _Tp, typename _Sequence = vector<_Tp>, |
455 | typename _Compare = less<typename _Sequence::value_type> > |
456 | class priority_queue |
457 | { |
458 | #ifdef _GLIBCXX_CONCEPT_CHECKS |
459 | // concept requirements |
460 | typedef typename _Sequence::value_type _Sequence_value_type; |
461 | # if __cplusplus < 201103L |
462 | __glibcxx_class_requires(_Tp, _SGIAssignableConcept) |
463 | # endif |
464 | __glibcxx_class_requires(_Sequence, _SequenceConcept) |
465 | __glibcxx_class_requires(_Sequence, _RandomAccessContainerConcept) |
466 | __glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept) |
467 | __glibcxx_class_requires4(_Compare, bool, _Tp, _Tp, |
468 | _BinaryFunctionConcept) |
469 | #endif |
470 | |
471 | #if __cplusplus >= 201103L |
472 | template<typename _Alloc> |
473 | using _Uses = typename |
474 | enable_if<uses_allocator<_Sequence, _Alloc>::value>::type; |
475 | |
476 | #if __cplusplus >= 201703L |
477 | // _GLIBCXX_RESOLVE_LIB_DEFECTS |
478 | // 2566. Requirements on the first template parameter of container |
479 | // adaptors |
480 | static_assert(is_same<_Tp, typename _Sequence::value_type>::value, |
481 | "value_type must be the same as the underlying container" ); |
482 | #endif // C++17 |
483 | #endif // C++11 |
484 | |
485 | public: |
486 | typedef typename _Sequence::value_type value_type; |
487 | typedef typename _Sequence::reference reference; |
488 | typedef typename _Sequence::const_reference const_reference; |
489 | typedef typename _Sequence::size_type size_type; |
490 | typedef _Sequence container_type; |
491 | // _GLIBCXX_RESOLVE_LIB_DEFECTS |
492 | // DR 2684. priority_queue lacking comparator typedef |
493 | typedef _Compare value_compare; |
494 | |
495 | protected: |
496 | // See queue::c for notes on these names. |
497 | _Sequence c; |
498 | _Compare comp; |
499 | |
500 | public: |
501 | /** |
502 | * @brief Default constructor creates no elements. |
503 | */ |
504 | #if __cplusplus < 201103L |
505 | explicit |
506 | priority_queue(const _Compare& __x = _Compare(), |
507 | const _Sequence& __s = _Sequence()) |
508 | : c(__s), comp(__x) |
509 | { std::make_heap(c.begin(), c.end(), comp); } |
510 | #else |
511 | template<typename _Seq = _Sequence, typename _Requires = typename |
512 | enable_if<__and_<is_default_constructible<_Compare>, |
513 | is_default_constructible<_Seq>>::value>::type> |
514 | priority_queue() |
515 | : c(), comp() { } |
516 | |
517 | explicit |
518 | priority_queue(const _Compare& __x, const _Sequence& __s) |
519 | : c(__s), comp(__x) |
520 | { std::make_heap(c.begin(), c.end(), comp); } |
521 | |
522 | explicit |
523 | priority_queue(const _Compare& __x, _Sequence&& __s = _Sequence()) |
524 | : c(std::move(__s)), comp(__x) |
525 | { std::make_heap(c.begin(), c.end(), comp); } |
526 | |
527 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>> |
528 | explicit |
529 | priority_queue(const _Alloc& __a) |
530 | : c(__a), comp() { } |
531 | |
532 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>> |
533 | priority_queue(const _Compare& __x, const _Alloc& __a) |
534 | : c(__a), comp(__x) { } |
535 | |
536 | // _GLIBCXX_RESOLVE_LIB_DEFECTS |
537 | // 2537. Constructors [...] taking allocators should call make_heap |
538 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>> |
539 | priority_queue(const _Compare& __x, const _Sequence& __c, |
540 | const _Alloc& __a) |
541 | : c(__c, __a), comp(__x) |
542 | { std::make_heap(c.begin(), c.end(), comp); } |
543 | |
544 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>> |
545 | priority_queue(const _Compare& __x, _Sequence&& __c, const _Alloc& __a) |
546 | : c(std::move(__c), __a), comp(__x) |
547 | { std::make_heap(c.begin(), c.end(), comp); } |
548 | |
549 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>> |
550 | priority_queue(const priority_queue& __q, const _Alloc& __a) |
551 | : c(__q.c, __a), comp(__q.comp) { } |
552 | |
553 | template<typename _Alloc, typename _Requires = _Uses<_Alloc>> |
554 | priority_queue(priority_queue&& __q, const _Alloc& __a) |
555 | : c(std::move(__q.c), __a), comp(std::move(__q.comp)) { } |
556 | #endif |
557 | |
558 | /** |
559 | * @brief Builds a %queue from a range. |
560 | * @param __first An input iterator. |
561 | * @param __last An input iterator. |
562 | * @param __x A comparison functor describing a strict weak ordering. |
563 | * @param __s An initial sequence with which to start. |
564 | * |
565 | * Begins by copying @a __s, inserting a copy of the elements |
566 | * from @a [first,last) into the copy of @a __s, then ordering |
567 | * the copy according to @a __x. |
568 | * |
569 | * For more information on function objects, see the |
570 | * documentation on @link functors functor base |
571 | * classes@endlink. |
572 | */ |
573 | #if __cplusplus < 201103L |
574 | template<typename _InputIterator> |
575 | priority_queue(_InputIterator __first, _InputIterator __last, |
576 | const _Compare& __x = _Compare(), |
577 | const _Sequence& __s = _Sequence()) |
578 | : c(__s), comp(__x) |
579 | { |
580 | __glibcxx_requires_valid_range(__first, __last); |
581 | c.insert(c.end(), __first, __last); |
582 | std::make_heap(c.begin(), c.end(), comp); |
583 | } |
584 | #else |
585 | template<typename _InputIterator> |
586 | priority_queue(_InputIterator __first, _InputIterator __last, |
587 | const _Compare& __x, |
588 | const _Sequence& __s) |
589 | : c(__s), comp(__x) |
590 | { |
591 | __glibcxx_requires_valid_range(__first, __last); |
592 | c.insert(c.end(), __first, __last); |
593 | std::make_heap(c.begin(), c.end(), comp); |
594 | } |
595 | |
596 | template<typename _InputIterator> |
597 | priority_queue(_InputIterator __first, _InputIterator __last, |
598 | const _Compare& __x = _Compare(), |
599 | _Sequence&& __s = _Sequence()) |
600 | : c(std::move(__s)), comp(__x) |
601 | { |
602 | __glibcxx_requires_valid_range(__first, __last); |
603 | c.insert(c.end(), __first, __last); |
604 | std::make_heap(c.begin(), c.end(), comp); |
605 | } |
606 | #endif |
607 | |
608 | /** |
609 | * Returns true if the %queue is empty. |
610 | */ |
611 | _GLIBCXX_NODISCARD bool |
612 | empty() const |
613 | { return c.empty(); } |
614 | |
615 | /** Returns the number of elements in the %queue. */ |
616 | size_type |
617 | size() const |
618 | { return c.size(); } |
619 | |
620 | /** |
621 | * Returns a read-only (constant) reference to the data at the first |
622 | * element of the %queue. |
623 | */ |
624 | const_reference |
625 | top() const |
626 | { |
627 | __glibcxx_requires_nonempty(); |
628 | return c.front(); |
629 | } |
630 | |
631 | /** |
632 | * @brief Add data to the %queue. |
633 | * @param __x Data to be added. |
634 | * |
635 | * This is a typical %queue operation. |
636 | * The time complexity of the operation depends on the underlying |
637 | * sequence. |
638 | */ |
639 | void |
640 | push(const value_type& __x) |
641 | { |
642 | c.push_back(__x); |
643 | std::push_heap(c.begin(), c.end(), comp); |
644 | } |
645 | |
646 | #if __cplusplus >= 201103L |
647 | void |
648 | push(value_type&& __x) |
649 | { |
650 | c.push_back(std::move(__x)); |
651 | std::push_heap(c.begin(), c.end(), comp); |
652 | } |
653 | |
654 | template<typename... _Args> |
655 | void |
656 | emplace(_Args&&... __args) |
657 | { |
658 | c.emplace_back(std::forward<_Args>(__args)...); |
659 | std::push_heap(c.begin(), c.end(), comp); |
660 | } |
661 | #endif |
662 | |
663 | /** |
664 | * @brief Removes first element. |
665 | * |
666 | * This is a typical %queue operation. It shrinks the %queue |
667 | * by one. The time complexity of the operation depends on the |
668 | * underlying sequence. |
669 | * |
670 | * Note that no data is returned, and if the first element's |
671 | * data is needed, it should be retrieved before pop() is |
672 | * called. |
673 | */ |
674 | void |
675 | pop() |
676 | { |
677 | __glibcxx_requires_nonempty(); |
678 | std::pop_heap(c.begin(), c.end(), comp); |
679 | c.pop_back(); |
680 | } |
681 | |
682 | #if __cplusplus >= 201103L |
683 | void |
684 | swap(priority_queue& __pq) |
685 | noexcept(__and_< |
686 | #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 |
687 | __is_nothrow_swappable<_Sequence>, |
688 | #else |
689 | __is_nothrow_swappable<_Tp>, |
690 | #endif |
691 | __is_nothrow_swappable<_Compare> |
692 | >::value) |
693 | { |
694 | using std::swap; |
695 | swap(c, __pq.c); |
696 | swap(comp, __pq.comp); |
697 | } |
698 | #endif // __cplusplus >= 201103L |
699 | }; |
700 | |
701 | #if __cpp_deduction_guides >= 201606 |
702 | template<typename _Compare, typename _Container, |
703 | typename = _RequireNotAllocator<_Compare>, |
704 | typename = _RequireNotAllocator<_Container>> |
705 | priority_queue(_Compare, _Container) |
706 | -> priority_queue<typename _Container::value_type, _Container, _Compare>; |
707 | |
708 | template<typename _InputIterator, typename _ValT |
709 | = typename iterator_traits<_InputIterator>::value_type, |
710 | typename _Compare = less<_ValT>, |
711 | typename _Container = vector<_ValT>, |
712 | typename = _RequireInputIter<_InputIterator>, |
713 | typename = _RequireNotAllocator<_Compare>, |
714 | typename = _RequireNotAllocator<_Container>> |
715 | priority_queue(_InputIterator, _InputIterator, _Compare = _Compare(), |
716 | _Container = _Container()) |
717 | -> priority_queue<_ValT, _Container, _Compare>; |
718 | |
719 | template<typename _Compare, typename _Container, typename _Allocator, |
720 | typename = _RequireNotAllocator<_Compare>, |
721 | typename = _RequireNotAllocator<_Container>, |
722 | typename = _RequireAllocator<_Allocator>> |
723 | priority_queue(_Compare, _Container, _Allocator) |
724 | -> priority_queue<typename _Container::value_type, _Container, _Compare>; |
725 | #endif |
726 | |
727 | // No equality/comparison operators are provided for priority_queue. |
728 | |
729 | #if __cplusplus >= 201103L |
730 | template<typename _Tp, typename _Sequence, typename _Compare> |
731 | inline |
732 | #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 |
733 | // Constrained free swap overload, see p0185r1 |
734 | typename enable_if<__and_<__is_swappable<_Sequence>, |
735 | __is_swappable<_Compare>>::value>::type |
736 | #else |
737 | void |
738 | #endif |
739 | swap(priority_queue<_Tp, _Sequence, _Compare>& __x, |
740 | priority_queue<_Tp, _Sequence, _Compare>& __y) |
741 | noexcept(noexcept(__x.swap(__y))) |
742 | { __x.swap(__y); } |
743 | |
744 | template<typename _Tp, typename _Sequence, typename _Compare, |
745 | typename _Alloc> |
746 | struct uses_allocator<priority_queue<_Tp, _Sequence, _Compare>, _Alloc> |
747 | : public uses_allocator<_Sequence, _Alloc>::type { }; |
748 | #endif // __cplusplus >= 201103L |
749 | |
750 | _GLIBCXX_END_NAMESPACE_VERSION |
751 | } // namespace |
752 | |
753 | #endif /* _STL_QUEUE_H */ |
754 | |