1// Queue implementation -*- C++ -*-
2
3// Copyright (C) 2001-2018 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/*
26 *
27 * Copyright (c) 1994
28 * Hewlett-Packard Company
29 *
30 * Permission to use, copy, modify, distribute and sell this software
31 * and its documentation for any purpose is hereby granted without fee,
32 * provided that the above copyright notice appear in all copies and
33 * that both that copyright notice and this permission notice appear
34 * in supporting documentation. Hewlett-Packard Company makes no
35 * representations about the suitability of this software for any
36 * purpose. It is provided "as is" without express or implied warranty.
37 *
38 *
39 * Copyright (c) 1996,1997
40 * Silicon Graphics Computer Systems, Inc.
41 *
42 * Permission to use, copy, modify, distribute and sell this software
43 * and its documentation for any purpose is hereby granted without fee,
44 * provided that the above copyright notice appear in all copies and
45 * that both that copyright notice and this permission notice appear
46 * in supporting documentation. Silicon Graphics makes no
47 * representations about the suitability of this software for any
48 * purpose. It is provided "as is" without express or implied warranty.
49 */
50
51/** @file 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
65namespace 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 __cplusplus >= 201103L
118 template<typename _Alloc>
119 using _Uses = typename
120 enable_if<uses_allocator<_Sequence, _Alloc>::value>::type;
121#endif
122
123 public:
124 typedef typename _Sequence::value_type value_type;
125 typedef typename _Sequence::reference reference;
126 typedef typename _Sequence::const_reference const_reference;
127 typedef typename _Sequence::size_type size_type;
128 typedef _Sequence container_type;
129
130 protected:
131 /* Maintainers wondering why this isn't uglified as per style
132 * guidelines should note that this name is specified in the standard,
133 * C++98 [23.2.3.1].
134 * (Why? Presumably for the same reason that it's protected instead
135 * of private: to allow derivation. But none of the other
136 * containers allow for derivation. Odd.)
137 */
138 /// @c c is the underlying container.
139 _Sequence c;
140
141 public:
142 /**
143 * @brief Default constructor creates no elements.
144 */
145#if __cplusplus < 201103L
146 explicit
147 queue(const _Sequence& __c = _Sequence())
148 : c(__c) { }
149#else
150 template<typename _Seq = _Sequence, typename _Requires = typename
151 enable_if<is_default_constructible<_Seq>::value>::type>
152 queue()
153 : c() { }
154
155 explicit
156 queue(const _Sequence& __c)
157 : c(__c) { }
158
159 explicit
160 queue(_Sequence&& __c)
161 : c(std::move(__c)) { }
162
163 template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
164 explicit
165 queue(const _Alloc& __a)
166 : c(__a) { }
167
168 template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
169 queue(const _Sequence& __c, const _Alloc& __a)
170 : c(__c, __a) { }
171
172 template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
173 queue(_Sequence&& __c, const _Alloc& __a)
174 : c(std::move(__c), __a) { }
175
176 template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
177 queue(const queue& __q, const _Alloc& __a)
178 : c(__q.c, __a) { }
179
180 template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
181 queue(queue&& __q, const _Alloc& __a)
182 : c(std::move(__q.c), __a) { }
183#endif
184
185 /**
186 * Returns true if the %queue is empty.
187 */
188 bool
189 empty() const
190 { return c.empty(); }
191
192 /** Returns the number of elements in the %queue. */
193 size_type
194 size() const
195 { return c.size(); }
196
197 /**
198 * Returns a read/write reference to the data at the first
199 * element of the %queue.
200 */
201 reference
202 front()
203 {
204 __glibcxx_requires_nonempty();
205 return c.front();
206 }
207
208 /**
209 * Returns a read-only (constant) reference to the data at the first
210 * element of the %queue.
211 */
212 const_reference
213 front() const
214 {
215 __glibcxx_requires_nonempty();
216 return c.front();
217 }
218
219 /**
220 * Returns a read/write reference to the data at the last
221 * element of the %queue.
222 */
223 reference
224 back()
225 {
226 __glibcxx_requires_nonempty();
227 return c.back();
228 }
229
230 /**
231 * Returns a read-only (constant) reference to the data at the last
232 * element of the %queue.
233 */
234 const_reference
235 back() const
236 {
237 __glibcxx_requires_nonempty();
238 return c.back();
239 }
240
241 /**
242 * @brief Add data to the end of the %queue.
243 * @param __x Data to be added.
244 *
245 * This is a typical %queue operation. The function creates an
246 * element at the end of the %queue and assigns the given data
247 * to it. The time complexity of the operation depends on the
248 * underlying sequence.
249 */
250 void
251 push(const value_type& __x)
252 { c.push_back(__x); }
253
254#if __cplusplus >= 201103L
255 void
256 push(value_type&& __x)
257 { c.push_back(std::move(__x)); }
258
259#if __cplusplus > 201402L
260 template<typename... _Args>
261 decltype(auto)
262 emplace(_Args&&... __args)
263 { return c.emplace_back(std::forward<_Args>(__args)...); }
264#else
265 template<typename... _Args>
266 void
267 emplace(_Args&&... __args)
268 { c.emplace_back(std::forward<_Args>(__args)...); }
269#endif
270#endif
271
272 /**
273 * @brief Removes first element.
274 *
275 * This is a typical %queue operation. It shrinks the %queue by one.
276 * The time complexity of the operation depends on the underlying
277 * sequence.
278 *
279 * Note that no data is returned, and if the first element's
280 * data is needed, it should be retrieved before pop() is
281 * called.
282 */
283 void
284 pop()
285 {
286 __glibcxx_requires_nonempty();
287 c.pop_front();
288 }
289
290#if __cplusplus >= 201103L
291 void
292 swap(queue& __q)
293#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
294 noexcept(__is_nothrow_swappable<_Sequence>::value)
295#else
296 noexcept(__is_nothrow_swappable<_Tp>::value)
297#endif
298 {
299 using std::swap;
300 swap(c, __q.c);
301 }
302#endif // __cplusplus >= 201103L
303 };
304
305#if __cpp_deduction_guides >= 201606
306 template<typename _Container,
307 typename = enable_if_t<!__is_allocator<_Container>::value>>
308 queue(_Container) -> queue<typename _Container::value_type, _Container>;
309
310 template<typename _Container, typename _Allocator,
311 typename = enable_if_t<!__is_allocator<_Container>::value>,
312 typename = enable_if_t<__is_allocator<_Allocator>::value>>
313 queue(_Container, _Allocator)
314 -> queue<typename _Container::value_type, _Container>;
315#endif
316
317 /**
318 * @brief Queue equality comparison.
319 * @param __x A %queue.
320 * @param __y A %queue of the same type as @a __x.
321 * @return True iff the size and elements of the queues are equal.
322 *
323 * This is an equivalence relation. Complexity and semantics depend on the
324 * underlying sequence type, but the expected rules are: this relation is
325 * linear in the size of the sequences, and queues are considered equivalent
326 * if their sequences compare equal.
327 */
328 template<typename _Tp, typename _Seq>
329 inline bool
330 operator==(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y)
331 { return __x.c == __y.c; }
332
333 /**
334 * @brief Queue ordering relation.
335 * @param __x A %queue.
336 * @param __y A %queue of the same type as @a x.
337 * @return True iff @a __x is lexicographically less than @a __y.
338 *
339 * This is an total ordering relation. Complexity and semantics
340 * depend on the underlying sequence type, but the expected rules
341 * are: this relation is linear in the size of the sequences, the
342 * elements must be comparable with @c <, and
343 * std::lexicographical_compare() is usually used to make the
344 * determination.
345 */
346 template<typename _Tp, typename _Seq>
347 inline bool
348 operator<(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y)
349 { return __x.c < __y.c; }
350
351 /// Based on operator==
352 template<typename _Tp, typename _Seq>
353 inline bool
354 operator!=(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y)
355 { return !(__x == __y); }
356
357 /// Based on operator<
358 template<typename _Tp, typename _Seq>
359 inline bool
360 operator>(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y)
361 { return __y < __x; }
362
363 /// Based on operator<
364 template<typename _Tp, typename _Seq>
365 inline bool
366 operator<=(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y)
367 { return !(__y < __x); }
368
369 /// Based on operator<
370 template<typename _Tp, typename _Seq>
371 inline bool
372 operator>=(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y)
373 { return !(__x < __y); }
374
375#if __cplusplus >= 201103L
376 template<typename _Tp, typename _Seq>
377 inline
378#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
379 // Constrained free swap overload, see p0185r1
380 typename enable_if<__is_swappable<_Seq>::value>::type
381#else
382 void
383#endif
384 swap(queue<_Tp, _Seq>& __x, queue<_Tp, _Seq>& __y)
385 noexcept(noexcept(__x.swap(__y)))
386 { __x.swap(__y); }
387
388 template<typename _Tp, typename _Seq, typename _Alloc>
389 struct uses_allocator<queue<_Tp, _Seq>, _Alloc>
390 : public uses_allocator<_Seq, _Alloc>::type { };
391#endif // __cplusplus >= 201103L
392
393 /**
394 * @brief A standard container automatically sorting its contents.
395 *
396 * @ingroup sequences
397 *
398 * @tparam _Tp Type of element.
399 * @tparam _Sequence Type of underlying sequence, defaults to vector<_Tp>.
400 * @tparam _Compare Comparison function object type, defaults to
401 * less<_Sequence::value_type>.
402 *
403 * This is not a true container, but an @e adaptor. It holds
404 * another container, and provides a wrapper interface to that
405 * container. The wrapper is what enforces priority-based sorting
406 * and %queue behavior. Very few of the standard container/sequence
407 * interface requirements are met (e.g., iterators).
408 *
409 * The second template parameter defines the type of the underlying
410 * sequence/container. It defaults to std::vector, but it can be
411 * any type that supports @c front(), @c push_back, @c pop_back,
412 * and random-access iterators, such as std::deque or an
413 * appropriate user-defined type.
414 *
415 * The third template parameter supplies the means of making
416 * priority comparisons. It defaults to @c less<value_type> but
417 * can be anything defining a strict weak ordering.
418 *
419 * Members not found in @a normal containers are @c container_type,
420 * which is a typedef for the second Sequence parameter, and @c
421 * push, @c pop, and @c top, which are standard %queue operations.
422 *
423 * @note No equality/comparison operators are provided for
424 * %priority_queue.
425 *
426 * @note Sorting of the elements takes place as they are added to,
427 * and removed from, the %priority_queue using the
428 * %priority_queue's member functions. If you access the elements
429 * by other means, and change their data such that the sorting
430 * order would be different, the %priority_queue will not re-sort
431 * the elements for you. (How could it know to do so?)
432 */
433 template<typename _Tp, typename _Sequence = vector<_Tp>,
434 typename _Compare = less<typename _Sequence::value_type> >
435 class priority_queue
436 {
437#ifdef _GLIBCXX_CONCEPT_CHECKS
438 // concept requirements
439 typedef typename _Sequence::value_type _Sequence_value_type;
440# if __cplusplus < 201103L
441 __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
442# endif
443 __glibcxx_class_requires(_Sequence, _SequenceConcept)
444 __glibcxx_class_requires(_Sequence, _RandomAccessContainerConcept)
445 __glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept)
446 __glibcxx_class_requires4(_Compare, bool, _Tp, _Tp,
447 _BinaryFunctionConcept)
448#endif
449
450#if __cplusplus >= 201103L
451 template<typename _Alloc>
452 using _Uses = typename
453 enable_if<uses_allocator<_Sequence, _Alloc>::value>::type;
454#endif
455
456 public:
457 typedef typename _Sequence::value_type value_type;
458 typedef typename _Sequence::reference reference;
459 typedef typename _Sequence::const_reference const_reference;
460 typedef typename _Sequence::size_type size_type;
461 typedef _Sequence container_type;
462 // _GLIBCXX_RESOLVE_LIB_DEFECTS
463 // DR 2684. priority_queue lacking comparator typedef
464 typedef _Compare value_compare;
465
466 protected:
467 // See queue::c for notes on these names.
468 _Sequence c;
469 _Compare comp;
470
471 public:
472 /**
473 * @brief Default constructor creates no elements.
474 */
475#if __cplusplus < 201103L
476 explicit
477 priority_queue(const _Compare& __x = _Compare(),
478 const _Sequence& __s = _Sequence())
479 : c(__s), comp(__x)
480 { std::make_heap(c.begin(), c.end(), comp); }
481#else
482 template<typename _Seq = _Sequence, typename _Requires = typename
483 enable_if<__and_<is_default_constructible<_Compare>,
484 is_default_constructible<_Seq>>::value>::type>
485 priority_queue()
486 : c(), comp() { }
487
488 explicit
489 priority_queue(const _Compare& __x, const _Sequence& __s)
490 : c(__s), comp(__x)
491 { std::make_heap(c.begin(), c.end(), comp); }
492
493 explicit
494 priority_queue(const _Compare& __x, _Sequence&& __s = _Sequence())
495 : c(std::move(__s)), comp(__x)
496 { std::make_heap(c.begin(), c.end(), comp); }
497
498 template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
499 explicit
500 priority_queue(const _Alloc& __a)
501 : c(__a), comp() { }
502
503 template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
504 priority_queue(const _Compare& __x, const _Alloc& __a)
505 : c(__a), comp(__x) { }
506
507 template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
508 priority_queue(const _Compare& __x, const _Sequence& __c,
509 const _Alloc& __a)
510 : c(__c, __a), comp(__x) { }
511
512 template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
513 priority_queue(const _Compare& __x, _Sequence&& __c, const _Alloc& __a)
514 : c(std::move(__c), __a), comp(__x) { }
515
516 template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
517 priority_queue(const priority_queue& __q, const _Alloc& __a)
518 : c(__q.c, __a), comp(__q.comp) { }
519
520 template<typename _Alloc, typename _Requires = _Uses<_Alloc>>
521 priority_queue(priority_queue&& __q, const _Alloc& __a)
522 : c(std::move(__q.c), __a), comp(std::move(__q.comp)) { }
523#endif
524
525 /**
526 * @brief Builds a %queue from a range.
527 * @param __first An input iterator.
528 * @param __last An input iterator.
529 * @param __x A comparison functor describing a strict weak ordering.
530 * @param __s An initial sequence with which to start.
531 *
532 * Begins by copying @a __s, inserting a copy of the elements
533 * from @a [first,last) into the copy of @a __s, then ordering
534 * the copy according to @a __x.
535 *
536 * For more information on function objects, see the
537 * documentation on @link functors functor base
538 * classes@endlink.
539 */
540#if __cplusplus < 201103L
541 template<typename _InputIterator>
542 priority_queue(_InputIterator __first, _InputIterator __last,
543 const _Compare& __x = _Compare(),
544 const _Sequence& __s = _Sequence())
545 : c(__s), comp(__x)
546 {
547 __glibcxx_requires_valid_range(__first, __last);
548 c.insert(c.end(), __first, __last);
549 std::make_heap(c.begin(), c.end(), comp);
550 }
551#else
552 template<typename _InputIterator>
553 priority_queue(_InputIterator __first, _InputIterator __last,
554 const _Compare& __x,
555 const _Sequence& __s)
556 : c(__s), comp(__x)
557 {
558 __glibcxx_requires_valid_range(__first, __last);
559 c.insert(c.end(), __first, __last);
560 std::make_heap(c.begin(), c.end(), comp);
561 }
562
563 template<typename _InputIterator>
564 priority_queue(_InputIterator __first, _InputIterator __last,
565 const _Compare& __x = _Compare(),
566 _Sequence&& __s = _Sequence())
567 : c(std::move(__s)), comp(__x)
568 {
569 __glibcxx_requires_valid_range(__first, __last);
570 c.insert(c.end(), __first, __last);
571 std::make_heap(c.begin(), c.end(), comp);
572 }
573#endif
574
575 /**
576 * Returns true if the %queue is empty.
577 */
578 bool
579 empty() const
580 { return c.empty(); }
581
582 /** Returns the number of elements in the %queue. */
583 size_type
584 size() const
585 { return c.size(); }
586
587 /**
588 * Returns a read-only (constant) reference to the data at the first
589 * element of the %queue.
590 */
591 const_reference
592 top() const
593 {
594 __glibcxx_requires_nonempty();
595 return c.front();
596 }
597
598 /**
599 * @brief Add data to the %queue.
600 * @param __x Data to be added.
601 *
602 * This is a typical %queue operation.
603 * The time complexity of the operation depends on the underlying
604 * sequence.
605 */
606 void
607 push(const value_type& __x)
608 {
609 c.push_back(__x);
610 std::push_heap(c.begin(), c.end(), comp);
611 }
612
613#if __cplusplus >= 201103L
614 void
615 push(value_type&& __x)
616 {
617 c.push_back(std::move(__x));
618 std::push_heap(c.begin(), c.end(), comp);
619 }
620
621 template<typename... _Args>
622 void
623 emplace(_Args&&... __args)
624 {
625 c.emplace_back(std::forward<_Args>(__args)...);
626 std::push_heap(c.begin(), c.end(), comp);
627 }
628#endif
629
630 /**
631 * @brief Removes first element.
632 *
633 * This is a typical %queue operation. It shrinks the %queue
634 * by one. The time complexity of the operation depends on the
635 * underlying sequence.
636 *
637 * Note that no data is returned, and if the first element's
638 * data is needed, it should be retrieved before pop() is
639 * called.
640 */
641 void
642 pop()
643 {
644 __glibcxx_requires_nonempty();
645 std::pop_heap(c.begin(), c.end(), comp);
646 c.pop_back();
647 }
648
649#if __cplusplus >= 201103L
650 void
651 swap(priority_queue& __pq)
652 noexcept(__and_<
653#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
654 __is_nothrow_swappable<_Sequence>,
655#else
656 __is_nothrow_swappable<_Tp>,
657#endif
658 __is_nothrow_swappable<_Compare>
659 >::value)
660 {
661 using std::swap;
662 swap(c, __pq.c);
663 swap(comp, __pq.comp);
664 }
665#endif // __cplusplus >= 201103L
666 };
667
668#if __cpp_deduction_guides >= 201606
669 template<typename _Compare, typename _Container,
670 typename = enable_if_t<!__is_allocator<_Compare>::value>,
671 typename = enable_if_t<!__is_allocator<_Container>::value>>
672 priority_queue(_Compare, _Container)
673 -> priority_queue<typename _Container::value_type, _Container, _Compare>;
674
675 template<typename _InputIterator, typename _ValT
676 = typename iterator_traits<_InputIterator>::value_type,
677 typename _Compare = less<_ValT>,
678 typename _Container = vector<_ValT>,
679 typename = _RequireInputIter<_InputIterator>,
680 typename = enable_if_t<!__is_allocator<_Compare>::value>,
681 typename = enable_if_t<!__is_allocator<_Container>::value>>
682 priority_queue(_InputIterator, _InputIterator, _Compare = _Compare(),
683 _Container = _Container())
684 -> priority_queue<_ValT, _Container, _Compare>;
685
686 template<typename _Compare, typename _Container, typename _Allocator,
687 typename = enable_if_t<!__is_allocator<_Compare>::value>,
688 typename = enable_if_t<!__is_allocator<_Container>::value>,
689 typename = enable_if_t<__is_allocator<_Allocator>::value>>
690 priority_queue(_Compare, _Container, _Allocator)
691 -> priority_queue<typename _Container::value_type, _Container, _Compare>;
692#endif
693
694 // No equality/comparison operators are provided for priority_queue.
695
696#if __cplusplus >= 201103L
697 template<typename _Tp, typename _Sequence, typename _Compare>
698 inline
699#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
700 // Constrained free swap overload, see p0185r1
701 typename enable_if<__and_<__is_swappable<_Sequence>,
702 __is_swappable<_Compare>>::value>::type
703#else
704 void
705#endif
706 swap(priority_queue<_Tp, _Sequence, _Compare>& __x,
707 priority_queue<_Tp, _Sequence, _Compare>& __y)
708 noexcept(noexcept(__x.swap(__y)))
709 { __x.swap(__y); }
710
711 template<typename _Tp, typename _Sequence, typename _Compare,
712 typename _Alloc>
713 struct uses_allocator<priority_queue<_Tp, _Sequence, _Compare>, _Alloc>
714 : public uses_allocator<_Sequence, _Alloc>::type { };
715#endif // __cplusplus >= 201103L
716
717_GLIBCXX_END_NAMESPACE_VERSION
718} // namespace
719
720#endif /* _STL_QUEUE_H */
721