1 // Queue implementation -*- C++ -*- 2 3 // Copyright (C) 2001-2022 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) { } 197 198 #if __cplusplus > 202002L 199 #define __cpp_lib_adaptor_iterator_pair_constructor 202106L 200 201 template<typename _InputIterator, 202 typename = _RequireInputIter<_InputIterator>> 203 queue(_InputIterator __first, _InputIterator __last) 204 : c(__first, __last) { } 205 206 template<typename _InputIterator, typename _Alloc, 207 typename = _RequireInputIter<_InputIterator>, 208 typename = _Uses<_Alloc>> 209 queue(_InputIterator __first, _InputIterator __last, const _Alloc& __a) 210 : c(__first, __last, __a) { } 211 #endif 212 #endif 213 214 /** 215 * Returns true if the %queue is empty. 216 */ 217 _GLIBCXX_NODISCARD bool 218 empty() const 219 { return c.empty(); } 220 221 /** Returns the number of elements in the %queue. */ 222 _GLIBCXX_NODISCARD 223 size_type 224 size() const 225 { return c.size(); } 226 227 /** 228 * Returns a read/write reference to the data at the first 229 * element of the %queue. 230 */ 231 _GLIBCXX_NODISCARD 232 reference 233 front() 234 { 235 __glibcxx_requires_nonempty(); 236 return c.front(); 237 } 238 239 /** 240 * Returns a read-only (constant) reference to the data at the first 241 * element of the %queue. 242 */ 243 _GLIBCXX_NODISCARD 244 const_reference 245 front() const 246 { 247 __glibcxx_requires_nonempty(); 248 return c.front(); 249 } 250 251 /** 252 * Returns a read/write reference to the data at the last 253 * element of the %queue. 254 */ 255 _GLIBCXX_NODISCARD 256 reference 257 back() 258 { 259 __glibcxx_requires_nonempty(); 260 return c.back(); 261 } 262 263 /** 264 * Returns a read-only (constant) reference to the data at the last 265 * element of the %queue. 266 */ 267 _GLIBCXX_NODISCARD 268 const_reference 269 back() const 270 { 271 __glibcxx_requires_nonempty(); 272 return c.back(); 273 } 274 275 /** 276 * @brief Add data to the end of the %queue. 277 * @param __x Data to be added. 278 * 279 * This is a typical %queue operation. The function creates an 280 * element at the end of the %queue and assigns the given data 281 * to it. The time complexity of the operation depends on the 282 * underlying sequence. 283 */ 284 void 285 push(const value_type& __x) 286 { c.push_back(__x); } 287 288 #if __cplusplus >= 201103L 289 void 290 push(value_type&& __x) 291 { c.push_back(std::move(__x)); } 292 293 #if __cplusplus > 201402L 294 template<typename... _Args> 295 decltype(auto) 296 emplace(_Args&&... __args) 297 { return c.emplace_back(std::forward<_Args>(__args)...); } 298 #else 299 template<typename... _Args> 300 void 301 emplace(_Args&&... __args) 302 { c.emplace_back(std::forward<_Args>(__args)...); } 303 #endif 304 #endif 305 306 /** 307 * @brief Removes first element. 308 * 309 * This is a typical %queue operation. It shrinks the %queue by one. 310 * The time complexity of the operation depends on the underlying 311 * sequence. 312 * 313 * Note that no data is returned, and if the first element's 314 * data is needed, it should be retrieved before pop() is 315 * called. 316 */ 317 void 318 pop() 319 { 320 __glibcxx_requires_nonempty(); 321 c.pop_front(); 322 } 323 324 #if __cplusplus >= 201103L 325 void 326 swap(queue& __q) 327 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 328 noexcept(__is_nothrow_swappable<_Sequence>::value) 329 #else 330 noexcept(__is_nothrow_swappable<_Tp>::value) 331 #endif 332 { 333 using std::swap; 334 swap(c, __q.c); 335 } 336 #endif // __cplusplus >= 201103L 337 }; 338 339 #if __cpp_deduction_guides >= 201606 340 template<typename _Container, 341 typename = _RequireNotAllocator<_Container>> 342 queue(_Container) -> queue<typename _Container::value_type, _Container>; 343 344 template<typename _Container, typename _Allocator, 345 typename = _RequireNotAllocator<_Container>> 346 queue(_Container, _Allocator) 347 -> queue<typename _Container::value_type, _Container>; 348 349 #ifdef __cpp_lib_adaptor_iterator_pair_constructor 350 template<typename _InputIterator, 351 typename _ValT 352 = typename iterator_traits<_InputIterator>::value_type, 353 typename = _RequireInputIter<_InputIterator>> 354 queue(_InputIterator, _InputIterator) -> queue<_ValT>; 355 356 template<typename _InputIterator, typename _Allocator, 357 typename _ValT 358 = typename iterator_traits<_InputIterator>::value_type, 359 typename = _RequireInputIter<_InputIterator>, 360 typename = _RequireAllocator<_Allocator>> 361 queue(_InputIterator, _InputIterator, _Allocator) 362 -> queue<_ValT, deque<_ValT, _Allocator>>; 363 #endif 364 #endif 365 366 /** 367 * @brief Queue equality comparison. 368 * @param __x A %queue. 369 * @param __y A %queue of the same type as @a __x. 370 * @return True iff the size and elements of the queues are equal. 371 * 372 * This is an equivalence relation. Complexity and semantics depend on the 373 * underlying sequence type, but the expected rules are: this relation is 374 * linear in the size of the sequences, and queues are considered equivalent 375 * if their sequences compare equal. 376 */ 377 template<typename _Tp, typename _Seq> 378 _GLIBCXX_NODISCARD 379 inline bool 380 operator==(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y) 381 { return __x.c == __y.c; } 382 383 /** 384 * @brief Queue ordering relation. 385 * @param __x A %queue. 386 * @param __y A %queue of the same type as @a x. 387 * @return True iff @a __x is lexicographically less than @a __y. 388 * 389 * This is an total ordering relation. Complexity and semantics 390 * depend on the underlying sequence type, but the expected rules 391 * are: this relation is linear in the size of the sequences, the 392 * elements must be comparable with @c <, and 393 * std::lexicographical_compare() is usually used to make the 394 * determination. 395 */ 396 template<typename _Tp, typename _Seq> 397 _GLIBCXX_NODISCARD 398 inline bool 399 operator<(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y) 400 { return __x.c < __y.c; } 401 402 /// Based on operator== 403 template<typename _Tp, typename _Seq> 404 _GLIBCXX_NODISCARD 405 inline bool 406 operator!=(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y) 407 { return !(__x == __y); } 408 409 /// Based on operator< 410 template<typename _Tp, typename _Seq> 411 _GLIBCXX_NODISCARD 412 inline bool 413 operator>(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y) 414 { return __y < __x; } 415 416 /// Based on operator< 417 template<typename _Tp, typename _Seq> 418 _GLIBCXX_NODISCARD 419 inline bool 420 operator<=(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y) 421 { return !(__y < __x); } 422 423 /// Based on operator< 424 template<typename _Tp, typename _Seq> 425 _GLIBCXX_NODISCARD 426 inline bool 427 operator>=(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y) 428 { return !(__x < __y); } 429 430 #if __cpp_lib_three_way_comparison 431 template<typename _Tp, three_way_comparable _Seq> 432 [[nodiscard]] 433 inline compare_three_way_result_t<_Seq> 434 operator<=>(const queue<_Tp, _Seq>& __x, const queue<_Tp, _Seq>& __y) 435 { return __x.c <=> __y.c; } 436 #endif 437 438 #if __cplusplus >= 201103L 439 template<typename _Tp, typename _Seq> 440 inline 441 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 442 // Constrained free swap overload, see p0185r1 443 typename enable_if<__is_swappable<_Seq>::value>::type 444 #else 445 void 446 #endif 447 swap(queue<_Tp, _Seq>& __x, queue<_Tp, _Seq>& __y) 448 noexcept(noexcept(__x.swap(__y))) 449 { __x.swap(__y); } 450 451 template<typename _Tp, typename _Seq, typename _Alloc> 452 struct uses_allocator<queue<_Tp, _Seq>, _Alloc> 453 : public uses_allocator<_Seq, _Alloc>::type { }; 454 #endif // __cplusplus >= 201103L 455 456 /** 457 * @brief A standard container automatically sorting its contents. 458 * 459 * @ingroup sequences 460 * 461 * @tparam _Tp Type of element. 462 * @tparam _Sequence Type of underlying sequence, defaults to vector<_Tp>. 463 * @tparam _Compare Comparison function object type, defaults to 464 * less<_Sequence::value_type>. 465 * 466 * This is not a true container, but an @e adaptor. It holds 467 * another container, and provides a wrapper interface to that 468 * container. The wrapper is what enforces priority-based sorting 469 * and %queue behavior. Very few of the standard container/sequence 470 * interface requirements are met (e.g., iterators). 471 * 472 * The second template parameter defines the type of the underlying 473 * sequence/container. It defaults to std::vector, but it can be 474 * any type that supports @c front(), @c push_back, @c pop_back, 475 * and random-access iterators, such as std::deque or an 476 * appropriate user-defined type. 477 * 478 * The third template parameter supplies the means of making 479 * priority comparisons. It defaults to @c less<value_type> but 480 * can be anything defining a strict weak ordering. 481 * 482 * Members not found in @a normal containers are @c container_type, 483 * which is a typedef for the second Sequence parameter, and @c 484 * push, @c pop, and @c top, which are standard %queue operations. 485 * 486 * @note No equality/comparison operators are provided for 487 * %priority_queue. 488 * 489 * @note Sorting of the elements takes place as they are added to, 490 * and removed from, the %priority_queue using the 491 * %priority_queue's member functions. If you access the elements 492 * by other means, and change their data such that the sorting 493 * order would be different, the %priority_queue will not re-sort 494 * the elements for you. (How could it know to do so?) 495 */ 496 template<typename _Tp, typename _Sequence = vector<_Tp>, 497 typename _Compare = less<typename _Sequence::value_type> > 498 class priority_queue 499 { 500 #ifdef _GLIBCXX_CONCEPT_CHECKS 501 // concept requirements 502 typedef typename _Sequence::value_type _Sequence_value_type; 503 # if __cplusplus < 201103L 504 __glibcxx_class_requires(_Tp, _SGIAssignableConcept) 505 # endif 506 __glibcxx_class_requires(_Sequence, _SequenceConcept) 507 __glibcxx_class_requires(_Sequence, _RandomAccessContainerConcept) 508 __glibcxx_class_requires2(_Tp, _Sequence_value_type, _SameTypeConcept) 509 __glibcxx_class_requires4(_Compare, bool, _Tp, _Tp, 510 _BinaryFunctionConcept) 511 #endif 512 513 #if __cplusplus >= 201103L 514 template<typename _Alloc> 515 using _Uses = typename 516 enable_if<uses_allocator<_Sequence, _Alloc>::value>::type; 517 518 #if __cplusplus >= 201703L 519 // _GLIBCXX_RESOLVE_LIB_DEFECTS 520 // 2566. Requirements on the first template parameter of container 521 // adaptors 522 static_assert(is_same<_Tp, typename _Sequence::value_type>::value, 523 "value_type must be the same as the underlying container"); 524 #endif // C++17 525 #endif // C++11 526 527 public: 528 typedef typename _Sequence::value_type value_type; 529 typedef typename _Sequence::reference reference; 530 typedef typename _Sequence::const_reference const_reference; 531 typedef typename _Sequence::size_type size_type; 532 typedef _Sequence container_type; 533 // _GLIBCXX_RESOLVE_LIB_DEFECTS 534 // DR 2684. priority_queue lacking comparator typedef 535 typedef _Compare value_compare; 536 537 protected: 538 // See queue::c for notes on these names. 539 _Sequence c; 540 _Compare comp; 541 542 public: 543 /** 544 * @brief Default constructor creates no elements. 545 */ 546 #if __cplusplus < 201103L 547 explicit 548 priority_queue(const _Compare& __x = _Compare(), 549 const _Sequence& __s = _Sequence()) 550 : c(__s), comp(__x) 551 { std::make_heap(c.begin(), c.end(), comp); } 552 #else 553 template<typename _Seq = _Sequence, typename _Requires = typename 554 enable_if<__and_<is_default_constructible<_Compare>, 555 is_default_constructible<_Seq>>::value>::type> 556 priority_queue() 557 : c(), comp() { } 558 559 explicit 560 priority_queue(const _Compare& __x, const _Sequence& __s) 561 : c(__s), comp(__x) 562 { std::make_heap(c.begin(), c.end(), comp); } 563 564 explicit 565 priority_queue(const _Compare& __x, _Sequence&& __s = _Sequence()) 566 : c(std::move(__s)), comp(__x) 567 { std::make_heap(c.begin(), c.end(), comp); } 568 569 template<typename _Alloc, typename _Requires = _Uses<_Alloc>> 570 explicit 571 priority_queue(const _Alloc& __a) 572 : c(__a), comp() { } 573 574 template<typename _Alloc, typename _Requires = _Uses<_Alloc>> 575 priority_queue(const _Compare& __x, const _Alloc& __a) 576 : c(__a), comp(__x) { } 577 578 // _GLIBCXX_RESOLVE_LIB_DEFECTS 579 // 2537. Constructors [...] taking allocators should call make_heap 580 template<typename _Alloc, typename _Requires = _Uses<_Alloc>> 581 priority_queue(const _Compare& __x, const _Sequence& __c, 582 const _Alloc& __a) 583 : c(__c, __a), comp(__x) 584 { std::make_heap(c.begin(), c.end(), comp); } 585 586 template<typename _Alloc, typename _Requires = _Uses<_Alloc>> 587 priority_queue(const _Compare& __x, _Sequence&& __c, const _Alloc& __a) 588 : c(std::move(__c), __a), comp(__x) 589 { std::make_heap(c.begin(), c.end(), comp); } 590 591 template<typename _Alloc, typename _Requires = _Uses<_Alloc>> 592 priority_queue(const priority_queue& __q, const _Alloc& __a) 593 : c(__q.c, __a), comp(__q.comp) { } 594 595 template<typename _Alloc, typename _Requires = _Uses<_Alloc>> 596 priority_queue(priority_queue&& __q, const _Alloc& __a) 597 : c(std::move(__q.c), __a), comp(std::move(__q.comp)) { } 598 #endif 599 600 /** 601 * @brief Builds a %queue from a range. 602 * @param __first An input iterator. 603 * @param __last An input iterator. 604 * @param __x A comparison functor describing a strict weak ordering. 605 * @param __s An initial sequence with which to start. 606 * 607 * Begins by copying @a __s, inserting a copy of the elements 608 * from @a [first,last) into the copy of @a __s, then ordering 609 * the copy according to @a __x. 610 * 611 * For more information on function objects, see the 612 * documentation on @link functors functor base 613 * classes@endlink. 614 */ 615 #if __cplusplus < 201103L 616 template<typename _InputIterator> 617 priority_queue(_InputIterator __first, _InputIterator __last, 618 const _Compare& __x = _Compare(), 619 const _Sequence& __s = _Sequence()) 620 : c(__s), comp(__x) 621 { 622 __glibcxx_requires_valid_range(__first, __last); 623 c.insert(c.end(), __first, __last); 624 std::make_heap(c.begin(), c.end(), comp); 625 } 626 #else 627 // _GLIBCXX_RESOLVE_LIB_DEFECTS 628 // 3529. priority_queue(first, last) should construct c with (first, last) 629 template<typename _InputIterator, 630 typename = std::_RequireInputIter<_InputIterator>> 631 priority_queue(_InputIterator __first, _InputIterator __last, 632 const _Compare& __x = _Compare()) 633 : c(__first, __last), comp(__x) 634 { std::make_heap(c.begin(), c.end(), comp); } 635 636 // _GLIBCXX_RESOLVE_LIB_DEFECTS 637 // 3522. Missing requirement on InputIterator template parameter 638 template<typename _InputIterator, 639 typename = std::_RequireInputIter<_InputIterator>> 640 priority_queue(_InputIterator __first, _InputIterator __last, 641 const _Compare& __x, const _Sequence& __s) 642 : c(__s), comp(__x) 643 { 644 __glibcxx_requires_valid_range(__first, __last); 645 c.insert(c.end(), __first, __last); 646 std::make_heap(c.begin(), c.end(), comp); 647 } 648 649 template<typename _InputIterator, 650 typename = std::_RequireInputIter<_InputIterator>> 651 priority_queue(_InputIterator __first, _InputIterator __last, 652 const _Compare& __x, _Sequence&& __s) 653 : c(std::move(__s)), comp(__x) 654 { 655 __glibcxx_requires_valid_range(__first, __last); 656 c.insert(c.end(), __first, __last); 657 std::make_heap(c.begin(), c.end(), comp); 658 } 659 660 // _GLIBCXX_RESOLVE_LIB_DEFECTS 661 // 3506. Missing allocator-extended constructors for priority_queue 662 template<typename _InputIterator, typename _Alloc, 663 typename = std::_RequireInputIter<_InputIterator>, 664 typename _Requires = _Uses<_Alloc>> 665 priority_queue(_InputIterator __first, _InputIterator __last, 666 const _Alloc& __alloc) 667 : c(__first, __last, __alloc), comp() 668 { std::make_heap(c.begin(), c.end(), comp); } 669 670 template<typename _InputIterator, typename _Alloc, 671 typename = std::_RequireInputIter<_InputIterator>, 672 typename _Requires = _Uses<_Alloc>> 673 priority_queue(_InputIterator __first, _InputIterator __last, 674 const _Compare& __x, const _Alloc& __alloc) 675 : c(__first, __last, __alloc), comp(__x) 676 { std::make_heap(c.begin(), c.end(), comp); } 677 678 template<typename _InputIterator, typename _Alloc, 679 typename = std::_RequireInputIter<_InputIterator>, 680 typename _Requires = _Uses<_Alloc>> 681 priority_queue(_InputIterator __first, _InputIterator __last, 682 const _Compare& __x, const _Sequence& __s, 683 const _Alloc& __alloc) 684 : c(__s, __alloc), comp(__x) 685 { 686 __glibcxx_requires_valid_range(__first, __last); 687 c.insert(c.end(), __first, __last); 688 std::make_heap(c.begin(), c.end(), comp); 689 } 690 691 template<typename _InputIterator, typename _Alloc, 692 typename _Requires = _Uses<_Alloc>> 693 priority_queue(_InputIterator __first, _InputIterator __last, 694 const _Compare& __x, _Sequence&& __s, 695 const _Alloc& __alloc) 696 : c(std::move(__s), __alloc), comp(__x) 697 { 698 __glibcxx_requires_valid_range(__first, __last); 699 c.insert(c.end(), __first, __last); 700 std::make_heap(c.begin(), c.end(), comp); 701 } 702 #endif 703 704 /** 705 * Returns true if the %queue is empty. 706 */ 707 _GLIBCXX_NODISCARD bool 708 empty() const 709 { return c.empty(); } 710 711 /** Returns the number of elements in the %queue. */ 712 _GLIBCXX_NODISCARD 713 size_type 714 size() const 715 { return c.size(); } 716 717 /** 718 * Returns a read-only (constant) reference to the data at the first 719 * element of the %queue. 720 */ 721 _GLIBCXX_NODISCARD 722 const_reference 723 top() const 724 { 725 __glibcxx_requires_nonempty(); 726 return c.front(); 727 } 728 729 /** 730 * @brief Add data to the %queue. 731 * @param __x Data to be added. 732 * 733 * This is a typical %queue operation. 734 * The time complexity of the operation depends on the underlying 735 * sequence. 736 */ 737 void 738 push(const value_type& __x) 739 { 740 c.push_back(__x); 741 std::push_heap(c.begin(), c.end(), comp); 742 } 743 744 #if __cplusplus >= 201103L 745 void 746 push(value_type&& __x) 747 { 748 c.push_back(std::move(__x)); 749 std::push_heap(c.begin(), c.end(), comp); 750 } 751 752 template<typename... _Args> 753 void 754 emplace(_Args&&... __args) 755 { 756 c.emplace_back(std::forward<_Args>(__args)...); 757 std::push_heap(c.begin(), c.end(), comp); 758 } 759 #endif 760 761 /** 762 * @brief Removes first element. 763 * 764 * This is a typical %queue operation. It shrinks the %queue 765 * by one. The time complexity of the operation depends on the 766 * underlying sequence. 767 * 768 * Note that no data is returned, and if the first element's 769 * data is needed, it should be retrieved before pop() is 770 * called. 771 */ 772 void 773 pop() 774 { 775 __glibcxx_requires_nonempty(); 776 std::pop_heap(c.begin(), c.end(), comp); 777 c.pop_back(); 778 } 779 780 #if __cplusplus >= 201103L 781 void 782 swap(priority_queue& __pq) 783 noexcept(__and_< 784 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 785 __is_nothrow_swappable<_Sequence>, 786 #else 787 __is_nothrow_swappable<_Tp>, 788 #endif 789 __is_nothrow_swappable<_Compare> 790 >::value) 791 { 792 using std::swap; 793 swap(c, __pq.c); 794 swap(comp, __pq.comp); 795 } 796 #endif // __cplusplus >= 201103L 797 }; 798 799 #if __cpp_deduction_guides >= 201606 800 template<typename _Compare, typename _Container, 801 typename = _RequireNotAllocator<_Compare>, 802 typename = _RequireNotAllocator<_Container>> 803 priority_queue(_Compare, _Container) 804 -> priority_queue<typename _Container::value_type, _Container, _Compare>; 805 806 template<typename _InputIterator, typename _ValT 807 = typename iterator_traits<_InputIterator>::value_type, 808 typename _Compare = less<_ValT>, 809 typename _Container = vector<_ValT>, 810 typename = _RequireInputIter<_InputIterator>, 811 typename = _RequireNotAllocator<_Compare>, 812 typename = _RequireNotAllocator<_Container>> 813 priority_queue(_InputIterator, _InputIterator, _Compare = _Compare(), 814 _Container = _Container()) 815 -> priority_queue<_ValT, _Container, _Compare>; 816 817 template<typename _Compare, typename _Container, typename _Allocator, 818 typename = _RequireNotAllocator<_Compare>, 819 typename = _RequireNotAllocator<_Container>> 820 priority_queue(_Compare, _Container, _Allocator) 821 -> priority_queue<typename _Container::value_type, _Container, _Compare>; 822 #endif 823 824 // No equality/comparison operators are provided for priority_queue. 825 826 #if __cplusplus >= 201103L 827 template<typename _Tp, typename _Sequence, typename _Compare> 828 inline 829 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 830 // Constrained free swap overload, see p0185r1 831 typename enable_if<__and_<__is_swappable<_Sequence>, 832 __is_swappable<_Compare>>::value>::type 833 #else 834 void 835 #endif 836 swap(priority_queue<_Tp, _Sequence, _Compare>& __x, 837 priority_queue<_Tp, _Sequence, _Compare>& __y) 838 noexcept(noexcept(__x.swap(__y))) 839 { __x.swap(__y); } 840 841 template<typename _Tp, typename _Sequence, typename _Compare, 842 typename _Alloc> 843 struct uses_allocator<priority_queue<_Tp, _Sequence, _Compare>, _Alloc> 844 : public uses_allocator<_Sequence, _Alloc>::type { }; 845 #endif // __cplusplus >= 201103L 846 847 _GLIBCXX_END_NAMESPACE_VERSION 848 } // namespace 849 850 #endif /* _STL_QUEUE_H */ 851
Indexes created Tue Feb 24 08:35:24 UTC 2026