1 // Multiset implementation -*- C++ -*- 2 3 // Copyright (C) 2001-2014 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 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_multiset.h 52 * This is an internal header file, included by other library headers. 53 * Do not attempt to use it directly. @headername{set} 54 */ 55 56 #ifndef _STL_MULTISET_H 57 #define _STL_MULTISET_H 1 58 59 #include <bits/concept_check.h> 60 #if __cplusplus >= 201103L 61 #include <initializer_list> 62 #endif 63 64 namespace std _GLIBCXX_VISIBILITY(default) 65 { 66 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER 67 68 /** 69 * @brief A standard container made up of elements, which can be retrieved 70 * in logarithmic time. 71 * 72 * @ingroup associative_containers 73 * 74 * 75 * @tparam _Key Type of key objects. 76 * @tparam _Compare Comparison function object type, defaults to less<_Key>. 77 * @tparam _Alloc Allocator type, defaults to allocator<_Key>. 78 * 79 * Meets the requirements of a <a href="tables.html#65">container</a>, a 80 * <a href="tables.html#66">reversible container</a>, and an 81 * <a href="tables.html#69">associative container</a> (using equivalent 82 * keys). For a @c multiset<Key> the key_type and value_type are Key. 83 * 84 * Multisets support bidirectional iterators. 85 * 86 * The private tree data is declared exactly the same way for set and 87 * multiset; the distinction is made entirely in how the tree functions are 88 * called (*_unique versus *_equal, same as the standard). 89 */ 90 template <typename _Key, typename _Compare = std::less<_Key>, 91 typename _Alloc = std::allocator<_Key> > 92 class multiset 93 { 94 // concept requirements 95 typedef typename _Alloc::value_type _Alloc_value_type; 96 __glibcxx_class_requires(_Key, _SGIAssignableConcept) 97 __glibcxx_class_requires4(_Compare, bool, _Key, _Key, 98 _BinaryFunctionConcept) 99 __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept) 100 101 public: 102 // typedefs: 103 typedef _Key key_type; 104 typedef _Key value_type; 105 typedef _Compare key_compare; 106 typedef _Compare value_compare; 107 typedef _Alloc allocator_type; 108 109 private: 110 /// This turns a red-black tree into a [multi]set. 111 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template 112 rebind<_Key>::other _Key_alloc_type; 113 114 typedef _Rb_tree<key_type, value_type, _Identity<value_type>, 115 key_compare, _Key_alloc_type> _Rep_type; 116 /// The actual tree structure. 117 _Rep_type _M_t; 118 119 typedef __gnu_cxx::__alloc_traits<_Key_alloc_type> _Alloc_traits; 120 121 public: 122 typedef typename _Alloc_traits::pointer pointer; 123 typedef typename _Alloc_traits::const_pointer const_pointer; 124 typedef typename _Alloc_traits::reference reference; 125 typedef typename _Alloc_traits::const_reference const_reference; 126 // _GLIBCXX_RESOLVE_LIB_DEFECTS 127 // DR 103. set::iterator is required to be modifiable, 128 // but this allows modification of keys. 129 typedef typename _Rep_type::const_iterator iterator; 130 typedef typename _Rep_type::const_iterator const_iterator; 131 typedef typename _Rep_type::const_reverse_iterator reverse_iterator; 132 typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator; 133 typedef typename _Rep_type::size_type size_type; 134 typedef typename _Rep_type::difference_type difference_type; 135 136 // allocation/deallocation 137 /** 138 * @brief Default constructor creates no elements. 139 */ 140 multiset() 141 : _M_t() { } 142 143 /** 144 * @brief Creates a %multiset with no elements. 145 * @param __comp Comparator to use. 146 * @param __a An allocator object. 147 */ 148 explicit 149 multiset(const _Compare& __comp, 150 const allocator_type& __a = allocator_type()) 151 : _M_t(__comp, _Key_alloc_type(__a)) { } 152 153 /** 154 * @brief Builds a %multiset from a range. 155 * @param __first An input iterator. 156 * @param __last An input iterator. 157 * 158 * Create a %multiset consisting of copies of the elements from 159 * [first,last). This is linear in N if the range is already sorted, 160 * and NlogN otherwise (where N is distance(__first,__last)). 161 */ 162 template<typename _InputIterator> 163 multiset(_InputIterator __first, _InputIterator __last) 164 : _M_t() 165 { _M_t._M_insert_equal(__first, __last); } 166 167 /** 168 * @brief Builds a %multiset from a range. 169 * @param __first An input iterator. 170 * @param __last An input iterator. 171 * @param __comp A comparison functor. 172 * @param __a An allocator object. 173 * 174 * Create a %multiset consisting of copies of the elements from 175 * [__first,__last). This is linear in N if the range is already sorted, 176 * and NlogN otherwise (where N is distance(__first,__last)). 177 */ 178 template<typename _InputIterator> 179 multiset(_InputIterator __first, _InputIterator __last, 180 const _Compare& __comp, 181 const allocator_type& __a = allocator_type()) 182 : _M_t(__comp, _Key_alloc_type(__a)) 183 { _M_t._M_insert_equal(__first, __last); } 184 185 /** 186 * @brief %Multiset copy constructor. 187 * @param __x A %multiset of identical element and allocator types. 188 * 189 * The newly-created %multiset uses a copy of the allocation object used 190 * by @a __x. 191 */ 192 multiset(const multiset& __x) 193 : _M_t(__x._M_t) { } 194 195 #if __cplusplus >= 201103L 196 /** 197 * @brief %Multiset move constructor. 198 * @param __x A %multiset of identical element and allocator types. 199 * 200 * The newly-created %multiset contains the exact contents of @a __x. 201 * The contents of @a __x are a valid, but unspecified %multiset. 202 */ 203 multiset(multiset&& __x) 204 noexcept(is_nothrow_copy_constructible<_Compare>::value) 205 : _M_t(std::move(__x._M_t)) { } 206 207 /** 208 * @brief Builds a %multiset from an initializer_list. 209 * @param __l An initializer_list. 210 * @param __comp A comparison functor. 211 * @param __a An allocator object. 212 * 213 * Create a %multiset consisting of copies of the elements from 214 * the list. This is linear in N if the list is already sorted, 215 * and NlogN otherwise (where N is @a __l.size()). 216 */ 217 multiset(initializer_list<value_type> __l, 218 const _Compare& __comp = _Compare(), 219 const allocator_type& __a = allocator_type()) 220 : _M_t(__comp, _Key_alloc_type(__a)) 221 { _M_t._M_insert_equal(__l.begin(), __l.end()); } 222 223 /// Allocator-extended default constructor. 224 explicit 225 multiset(const allocator_type& __a) 226 : _M_t(_Compare(), _Key_alloc_type(__a)) { } 227 228 /// Allocator-extended copy constructor. 229 multiset(const multiset& __m, const allocator_type& __a) 230 : _M_t(__m._M_t, _Key_alloc_type(__a)) { } 231 232 /// Allocator-extended move constructor. 233 multiset(multiset&& __m, const allocator_type& __a) 234 noexcept(is_nothrow_copy_constructible<_Compare>::value 235 && _Alloc_traits::_S_always_equal()) 236 : _M_t(std::move(__m._M_t), _Key_alloc_type(__a)) { } 237 238 /// Allocator-extended initialier-list constructor. 239 multiset(initializer_list<value_type> __l, const allocator_type& __a) 240 : _M_t(_Compare(), _Key_alloc_type(__a)) 241 { _M_t._M_insert_equal(__l.begin(), __l.end()); } 242 243 /// Allocator-extended range constructor. 244 template<typename _InputIterator> 245 multiset(_InputIterator __first, _InputIterator __last, 246 const allocator_type& __a) 247 : _M_t(_Compare(), _Key_alloc_type(__a)) 248 { _M_t._M_insert_equal(__first, __last); } 249 #endif 250 251 /** 252 * @brief %Multiset assignment operator. 253 * @param __x A %multiset of identical element and allocator types. 254 * 255 * All the elements of @a __x are copied, but unlike the copy 256 * constructor, the allocator object is not copied. 257 */ 258 multiset& 259 operator=(const multiset& __x) 260 { 261 _M_t = __x._M_t; 262 return *this; 263 } 264 265 #if __cplusplus >= 201103L 266 /** 267 * @brief %Multiset move assignment operator. 268 * @param __x A %multiset of identical element and allocator types. 269 * 270 * The contents of @a __x are moved into this %multiset (without 271 * copying if the allocators compare equal or get moved on assignment). 272 * Afterwards @a __x is in a valid, but unspecified state. 273 */ 274 multiset& 275 operator=(multiset&& __x) noexcept(_Alloc_traits::_S_nothrow_move()) 276 { 277 if (!_M_t._M_move_assign(__x._M_t)) 278 { 279 // The rvalue's allocator cannot be moved and is not equal, 280 // so we need to individually move each element. 281 clear(); 282 insert(std::__make_move_if_noexcept_iterator(__x._M_t.begin()), 283 std::__make_move_if_noexcept_iterator(__x._M_t.end())); 284 __x.clear(); 285 } 286 return *this; 287 } 288 289 /** 290 * @brief %Multiset list assignment operator. 291 * @param __l An initializer_list. 292 * 293 * This function fills a %multiset with copies of the elements in the 294 * initializer list @a __l. 295 * 296 * Note that the assignment completely changes the %multiset and 297 * that the resulting %multiset's size is the same as the number 298 * of elements assigned. Old data may be lost. 299 */ 300 multiset& 301 operator=(initializer_list<value_type> __l) 302 { 303 this->clear(); 304 this->insert(__l.begin(), __l.end()); 305 return *this; 306 } 307 #endif 308 309 // accessors: 310 311 /// Returns the comparison object. 312 key_compare 313 key_comp() const 314 { return _M_t.key_comp(); } 315 /// Returns the comparison object. 316 value_compare 317 value_comp() const 318 { return _M_t.key_comp(); } 319 /// Returns the memory allocation object. 320 allocator_type 321 get_allocator() const _GLIBCXX_NOEXCEPT 322 { return allocator_type(_M_t.get_allocator()); } 323 324 /** 325 * Returns a read-only (constant) iterator that points to the first 326 * element in the %multiset. Iteration is done in ascending order 327 * according to the keys. 328 */ 329 iterator 330 begin() const _GLIBCXX_NOEXCEPT 331 { return _M_t.begin(); } 332 333 /** 334 * Returns a read-only (constant) iterator that points one past the last 335 * element in the %multiset. Iteration is done in ascending order 336 * according to the keys. 337 */ 338 iterator 339 end() const _GLIBCXX_NOEXCEPT 340 { return _M_t.end(); } 341 342 /** 343 * Returns a read-only (constant) reverse iterator that points to the 344 * last element in the %multiset. Iteration is done in descending order 345 * according to the keys. 346 */ 347 reverse_iterator 348 rbegin() const _GLIBCXX_NOEXCEPT 349 { return _M_t.rbegin(); } 350 351 /** 352 * Returns a read-only (constant) reverse iterator that points to the 353 * last element in the %multiset. Iteration is done in descending order 354 * according to the keys. 355 */ 356 reverse_iterator 357 rend() const _GLIBCXX_NOEXCEPT 358 { return _M_t.rend(); } 359 360 #if __cplusplus >= 201103L 361 /** 362 * Returns a read-only (constant) iterator that points to the first 363 * element in the %multiset. Iteration is done in ascending order 364 * according to the keys. 365 */ 366 iterator 367 cbegin() const noexcept 368 { return _M_t.begin(); } 369 370 /** 371 * Returns a read-only (constant) iterator that points one past the last 372 * element in the %multiset. Iteration is done in ascending order 373 * according to the keys. 374 */ 375 iterator 376 cend() const noexcept 377 { return _M_t.end(); } 378 379 /** 380 * Returns a read-only (constant) reverse iterator that points to the 381 * last element in the %multiset. Iteration is done in descending order 382 * according to the keys. 383 */ 384 reverse_iterator 385 crbegin() const noexcept 386 { return _M_t.rbegin(); } 387 388 /** 389 * Returns a read-only (constant) reverse iterator that points to the 390 * last element in the %multiset. Iteration is done in descending order 391 * according to the keys. 392 */ 393 reverse_iterator 394 crend() const noexcept 395 { return _M_t.rend(); } 396 #endif 397 398 /// Returns true if the %set is empty. 399 bool 400 empty() const _GLIBCXX_NOEXCEPT 401 { return _M_t.empty(); } 402 403 /// Returns the size of the %set. 404 size_type 405 size() const _GLIBCXX_NOEXCEPT 406 { return _M_t.size(); } 407 408 /// Returns the maximum size of the %set. 409 size_type 410 max_size() const _GLIBCXX_NOEXCEPT 411 { return _M_t.max_size(); } 412 413 /** 414 * @brief Swaps data with another %multiset. 415 * @param __x A %multiset of the same element and allocator types. 416 * 417 * This exchanges the elements between two multisets in constant time. 418 * (It is only swapping a pointer, an integer, and an instance of the @c 419 * Compare type (which itself is often stateless and empty), so it should 420 * be quite fast.) 421 * Note that the global std::swap() function is specialized such that 422 * std::swap(s1,s2) will feed to this function. 423 */ 424 void 425 swap(multiset& __x) 426 #if __cplusplus >= 201103L 427 noexcept(_Alloc_traits::_S_nothrow_swap()) 428 #endif 429 { _M_t.swap(__x._M_t); } 430 431 // insert/erase 432 #if __cplusplus >= 201103L 433 /** 434 * @brief Builds and inserts an element into the %multiset. 435 * @param __args Arguments used to generate the element instance to be 436 * inserted. 437 * @return An iterator that points to the inserted element. 438 * 439 * This function inserts an element into the %multiset. Contrary 440 * to a std::set the %multiset does not rely on unique keys and thus 441 * multiple copies of the same element can be inserted. 442 * 443 * Insertion requires logarithmic time. 444 */ 445 template<typename... _Args> 446 iterator 447 emplace(_Args&&... __args) 448 { return _M_t._M_emplace_equal(std::forward<_Args>(__args)...); } 449 450 /** 451 * @brief Builds and inserts an element into the %multiset. 452 * @param __pos An iterator that serves as a hint as to where the 453 * element should be inserted. 454 * @param __args Arguments used to generate the element instance to be 455 * inserted. 456 * @return An iterator that points to the inserted element. 457 * 458 * This function inserts an element into the %multiset. Contrary 459 * to a std::set the %multiset does not rely on unique keys and thus 460 * multiple copies of the same element can be inserted. 461 * 462 * Note that the first parameter is only a hint and can potentially 463 * improve the performance of the insertion process. A bad hint would 464 * cause no gains in efficiency. 465 * 466 * See http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html 467 * for more on @a hinting. 468 * 469 * Insertion requires logarithmic time (if the hint is not taken). 470 */ 471 template<typename... _Args> 472 iterator 473 emplace_hint(const_iterator __pos, _Args&&... __args) 474 { 475 return _M_t._M_emplace_hint_equal(__pos, 476 std::forward<_Args>(__args)...); 477 } 478 #endif 479 480 /** 481 * @brief Inserts an element into the %multiset. 482 * @param __x Element to be inserted. 483 * @return An iterator that points to the inserted element. 484 * 485 * This function inserts an element into the %multiset. Contrary 486 * to a std::set the %multiset does not rely on unique keys and thus 487 * multiple copies of the same element can be inserted. 488 * 489 * Insertion requires logarithmic time. 490 */ 491 iterator 492 insert(const value_type& __x) 493 { return _M_t._M_insert_equal(__x); } 494 495 #if __cplusplus >= 201103L 496 iterator 497 insert(value_type&& __x) 498 { return _M_t._M_insert_equal(std::move(__x)); } 499 #endif 500 501 /** 502 * @brief Inserts an element into the %multiset. 503 * @param __position An iterator that serves as a hint as to where the 504 * element should be inserted. 505 * @param __x Element to be inserted. 506 * @return An iterator that points to the inserted element. 507 * 508 * This function inserts an element into the %multiset. Contrary 509 * to a std::set the %multiset does not rely on unique keys and thus 510 * multiple copies of the same element can be inserted. 511 * 512 * Note that the first parameter is only a hint and can potentially 513 * improve the performance of the insertion process. A bad hint would 514 * cause no gains in efficiency. 515 * 516 * See http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html 517 * for more on @a hinting. 518 * 519 * Insertion requires logarithmic time (if the hint is not taken). 520 */ 521 iterator 522 insert(const_iterator __position, const value_type& __x) 523 { return _M_t._M_insert_equal_(__position, __x); } 524 525 #if __cplusplus >= 201103L 526 iterator 527 insert(const_iterator __position, value_type&& __x) 528 { return _M_t._M_insert_equal_(__position, std::move(__x)); } 529 #endif 530 531 /** 532 * @brief A template function that tries to insert a range of elements. 533 * @param __first Iterator pointing to the start of the range to be 534 * inserted. 535 * @param __last Iterator pointing to the end of the range. 536 * 537 * Complexity similar to that of the range constructor. 538 */ 539 template<typename _InputIterator> 540 void 541 insert(_InputIterator __first, _InputIterator __last) 542 { _M_t._M_insert_equal(__first, __last); } 543 544 #if __cplusplus >= 201103L 545 /** 546 * @brief Attempts to insert a list of elements into the %multiset. 547 * @param __l A std::initializer_list<value_type> of elements 548 * to be inserted. 549 * 550 * Complexity similar to that of the range constructor. 551 */ 552 void 553 insert(initializer_list<value_type> __l) 554 { this->insert(__l.begin(), __l.end()); } 555 #endif 556 557 #if __cplusplus >= 201103L 558 // _GLIBCXX_RESOLVE_LIB_DEFECTS 559 // DR 130. Associative erase should return an iterator. 560 /** 561 * @brief Erases an element from a %multiset. 562 * @param __position An iterator pointing to the element to be erased. 563 * @return An iterator pointing to the element immediately following 564 * @a position prior to the element being erased. If no such 565 * element exists, end() is returned. 566 * 567 * This function erases an element, pointed to by the given iterator, 568 * from a %multiset. Note that this function only erases the element, 569 * and that if the element is itself a pointer, the pointed-to memory is 570 * not touched in any way. Managing the pointer is the user's 571 * responsibility. 572 */ 573 _GLIBCXX_ABI_TAG_CXX11 574 iterator 575 erase(const_iterator __position) 576 { return _M_t.erase(__position); } 577 #else 578 /** 579 * @brief Erases an element from a %multiset. 580 * @param __position An iterator pointing to the element to be erased. 581 * 582 * This function erases an element, pointed to by the given iterator, 583 * from a %multiset. Note that this function only erases the element, 584 * and that if the element is itself a pointer, the pointed-to memory is 585 * not touched in any way. Managing the pointer is the user's 586 * responsibility. 587 */ 588 void 589 erase(iterator __position) 590 { _M_t.erase(__position); } 591 #endif 592 593 /** 594 * @brief Erases elements according to the provided key. 595 * @param __x Key of element to be erased. 596 * @return The number of elements erased. 597 * 598 * This function erases all elements located by the given key from a 599 * %multiset. 600 * Note that this function only erases the element, and that if 601 * the element is itself a pointer, the pointed-to memory is not touched 602 * in any way. Managing the pointer is the user's responsibility. 603 */ 604 size_type 605 erase(const key_type& __x) 606 { return _M_t.erase(__x); } 607 608 #if __cplusplus >= 201103L 609 // _GLIBCXX_RESOLVE_LIB_DEFECTS 610 // DR 130. Associative erase should return an iterator. 611 /** 612 * @brief Erases a [first,last) range of elements from a %multiset. 613 * @param __first Iterator pointing to the start of the range to be 614 * erased. 615 * @param __last Iterator pointing to the end of the range to 616 * be erased. 617 * @return The iterator @a last. 618 * 619 * This function erases a sequence of elements from a %multiset. 620 * Note that this function only erases the elements, and that if 621 * the elements themselves are pointers, the pointed-to memory is not 622 * touched in any way. Managing the pointer is the user's 623 * responsibility. 624 */ 625 _GLIBCXX_ABI_TAG_CXX11 626 iterator 627 erase(const_iterator __first, const_iterator __last) 628 { return _M_t.erase(__first, __last); } 629 #else 630 /** 631 * @brief Erases a [first,last) range of elements from a %multiset. 632 * @param first Iterator pointing to the start of the range to be 633 * erased. 634 * @param last Iterator pointing to the end of the range to be erased. 635 * 636 * This function erases a sequence of elements from a %multiset. 637 * Note that this function only erases the elements, and that if 638 * the elements themselves are pointers, the pointed-to memory is not 639 * touched in any way. Managing the pointer is the user's 640 * responsibility. 641 */ 642 void 643 erase(iterator __first, iterator __last) 644 { _M_t.erase(__first, __last); } 645 #endif 646 647 /** 648 * Erases all elements in a %multiset. Note that this function only 649 * erases the elements, and that if the elements themselves are pointers, 650 * the pointed-to memory is not touched in any way. Managing the pointer 651 * is the user's responsibility. 652 */ 653 void 654 clear() _GLIBCXX_NOEXCEPT 655 { _M_t.clear(); } 656 657 // multiset operations: 658 659 /** 660 * @brief Finds the number of elements with given key. 661 * @param __x Key of elements to be located. 662 * @return Number of elements with specified key. 663 */ 664 size_type 665 count(const key_type& __x) const 666 { return _M_t.count(__x); } 667 668 // _GLIBCXX_RESOLVE_LIB_DEFECTS 669 // 214. set::find() missing const overload 670 //@{ 671 /** 672 * @brief Tries to locate an element in a %set. 673 * @param __x Element to be located. 674 * @return Iterator pointing to sought-after element, or end() if not 675 * found. 676 * 677 * This function takes a key and tries to locate the element with which 678 * the key matches. If successful the function returns an iterator 679 * pointing to the sought after element. If unsuccessful it returns the 680 * past-the-end ( @c end() ) iterator. 681 */ 682 iterator 683 find(const key_type& __x) 684 { return _M_t.find(__x); } 685 686 const_iterator 687 find(const key_type& __x) const 688 { return _M_t.find(__x); } 689 //@} 690 691 //@{ 692 /** 693 * @brief Finds the beginning of a subsequence matching given key. 694 * @param __x Key to be located. 695 * @return Iterator pointing to first element equal to or greater 696 * than key, or end(). 697 * 698 * This function returns the first element of a subsequence of elements 699 * that matches the given key. If unsuccessful it returns an iterator 700 * pointing to the first element that has a greater value than given key 701 * or end() if no such element exists. 702 */ 703 iterator 704 lower_bound(const key_type& __x) 705 { return _M_t.lower_bound(__x); } 706 707 const_iterator 708 lower_bound(const key_type& __x) const 709 { return _M_t.lower_bound(__x); } 710 //@} 711 712 //@{ 713 /** 714 * @brief Finds the end of a subsequence matching given key. 715 * @param __x Key to be located. 716 * @return Iterator pointing to the first element 717 * greater than key, or end(). 718 */ 719 iterator 720 upper_bound(const key_type& __x) 721 { return _M_t.upper_bound(__x); } 722 723 const_iterator 724 upper_bound(const key_type& __x) const 725 { return _M_t.upper_bound(__x); } 726 //@} 727 728 //@{ 729 /** 730 * @brief Finds a subsequence matching given key. 731 * @param __x Key to be located. 732 * @return Pair of iterators that possibly points to the subsequence 733 * matching given key. 734 * 735 * This function is equivalent to 736 * @code 737 * std::make_pair(c.lower_bound(val), 738 * c.upper_bound(val)) 739 * @endcode 740 * (but is faster than making the calls separately). 741 * 742 * This function probably only makes sense for multisets. 743 */ 744 std::pair<iterator, iterator> 745 equal_range(const key_type& __x) 746 { return _M_t.equal_range(__x); } 747 748 std::pair<const_iterator, const_iterator> 749 equal_range(const key_type& __x) const 750 { return _M_t.equal_range(__x); } 751 //@} 752 753 template<typename _K1, typename _C1, typename _A1> 754 friend bool 755 operator==(const multiset<_K1, _C1, _A1>&, 756 const multiset<_K1, _C1, _A1>&); 757 758 template<typename _K1, typename _C1, typename _A1> 759 friend bool 760 operator< (const multiset<_K1, _C1, _A1>&, 761 const multiset<_K1, _C1, _A1>&); 762 }; 763 764 /** 765 * @brief Multiset equality comparison. 766 * @param __x A %multiset. 767 * @param __y A %multiset of the same type as @a __x. 768 * @return True iff the size and elements of the multisets are equal. 769 * 770 * This is an equivalence relation. It is linear in the size of the 771 * multisets. 772 * Multisets are considered equivalent if their sizes are equal, and if 773 * corresponding elements compare equal. 774 */ 775 template<typename _Key, typename _Compare, typename _Alloc> 776 inline bool 777 operator==(const multiset<_Key, _Compare, _Alloc>& __x, 778 const multiset<_Key, _Compare, _Alloc>& __y) 779 { return __x._M_t == __y._M_t; } 780 781 /** 782 * @brief Multiset ordering relation. 783 * @param __x A %multiset. 784 * @param __y A %multiset of the same type as @a __x. 785 * @return True iff @a __x is lexicographically less than @a __y. 786 * 787 * This is a total ordering relation. It is linear in the size of the 788 * sets. The elements must be comparable with @c <. 789 * 790 * See std::lexicographical_compare() for how the determination is made. 791 */ 792 template<typename _Key, typename _Compare, typename _Alloc> 793 inline bool 794 operator<(const multiset<_Key, _Compare, _Alloc>& __x, 795 const multiset<_Key, _Compare, _Alloc>& __y) 796 { return __x._M_t < __y._M_t; } 797 798 /// Returns !(x == y). 799 template<typename _Key, typename _Compare, typename _Alloc> 800 inline bool 801 operator!=(const multiset<_Key, _Compare, _Alloc>& __x, 802 const multiset<_Key, _Compare, _Alloc>& __y) 803 { return !(__x == __y); } 804 805 /// Returns y < x. 806 template<typename _Key, typename _Compare, typename _Alloc> 807 inline bool 808 operator>(const multiset<_Key,_Compare,_Alloc>& __x, 809 const multiset<_Key,_Compare,_Alloc>& __y) 810 { return __y < __x; } 811 812 /// Returns !(y < x) 813 template<typename _Key, typename _Compare, typename _Alloc> 814 inline bool 815 operator<=(const multiset<_Key, _Compare, _Alloc>& __x, 816 const multiset<_Key, _Compare, _Alloc>& __y) 817 { return !(__y < __x); } 818 819 /// Returns !(x < y) 820 template<typename _Key, typename _Compare, typename _Alloc> 821 inline bool 822 operator>=(const multiset<_Key, _Compare, _Alloc>& __x, 823 const multiset<_Key, _Compare, _Alloc>& __y) 824 { return !(__x < __y); } 825 826 /// See std::multiset::swap(). 827 template<typename _Key, typename _Compare, typename _Alloc> 828 inline void 829 swap(multiset<_Key, _Compare, _Alloc>& __x, 830 multiset<_Key, _Compare, _Alloc>& __y) 831 { __x.swap(__y); } 832 833 _GLIBCXX_END_NAMESPACE_CONTAINER 834 } // namespace std 835 836 #endif /* _STL_MULTISET_H */ 837
