1 // Multimap implementation -*- C++ -*- 2 3 // Copyright (C) 2001-2013 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_multimap.h 52 * This is an internal header file, included by other library headers. 53 * Do not attempt to use it directly. @headername{map} 54 */ 55 56 #ifndef _STL_MULTIMAP_H 57 #define _STL_MULTIMAP_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 (key,value) pairs, which can be 70 * retrieved based on a key, in logarithmic time. 71 * 72 * @ingroup associative_containers 73 * 74 * @tparam _Key Type of key objects. 75 * @tparam _Tp Type of mapped objects. 76 * @tparam _Compare Comparison function object type, defaults to less<_Key>. 77 * @tparam _Alloc Allocator type, defaults to 78 * allocator<pair<const _Key, _Tp>. 79 * 80 * Meets the requirements of a <a href="tables.html#65">container</a>, a 81 * <a href="tables.html#66">reversible container</a>, and an 82 * <a href="tables.html#69">associative container</a> (using equivalent 83 * keys). For a @c multimap<Key,T> the key_type is Key, the mapped_type 84 * is T, and the value_type is std::pair<const Key,T>. 85 * 86 * Multimaps support bidirectional iterators. 87 * 88 * The private tree data is declared exactly the same way for map and 89 * multimap; the distinction is made entirely in how the tree functions are 90 * called (*_unique versus *_equal, same as the standard). 91 */ 92 template <typename _Key, typename _Tp, 93 typename _Compare = std::less<_Key>, 94 typename _Alloc = std::allocator<std::pair<const _Key, _Tp> > > 95 class multimap 96 { 97 public: 98 typedef _Key key_type; 99 typedef _Tp mapped_type; 100 typedef std::pair<const _Key, _Tp> value_type; 101 typedef _Compare key_compare; 102 typedef _Alloc allocator_type; 103 104 private: 105 // concept requirements 106 typedef typename _Alloc::value_type _Alloc_value_type; 107 __glibcxx_class_requires(_Tp, _SGIAssignableConcept) 108 __glibcxx_class_requires4(_Compare, bool, _Key, _Key, 109 _BinaryFunctionConcept) 110 __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept) 111 112 public: 113 class value_compare 114 : public std::binary_function<value_type, value_type, bool> 115 { 116 friend class multimap<_Key, _Tp, _Compare, _Alloc>; 117 protected: 118 _Compare comp; 119 120 value_compare(_Compare __c) 121 : comp(__c) { } 122 123 public: 124 bool operator()(const value_type& __x, const value_type& __y) const 125 { return comp(__x.first, __y.first); } 126 }; 127 128 private: 129 /// This turns a red-black tree into a [multi]map. 130 typedef typename _Alloc::template rebind<value_type>::other 131 _Pair_alloc_type; 132 133 typedef _Rb_tree<key_type, value_type, _Select1st<value_type>, 134 key_compare, _Pair_alloc_type> _Rep_type; 135 /// The actual tree structure. 136 _Rep_type _M_t; 137 138 public: 139 // many of these are specified differently in ISO, but the following are 140 // "functionally equivalent" 141 typedef typename _Pair_alloc_type::pointer pointer; 142 typedef typename _Pair_alloc_type::const_pointer const_pointer; 143 typedef typename _Pair_alloc_type::reference reference; 144 typedef typename _Pair_alloc_type::const_reference const_reference; 145 typedef typename _Rep_type::iterator iterator; 146 typedef typename _Rep_type::const_iterator const_iterator; 147 typedef typename _Rep_type::size_type size_type; 148 typedef typename _Rep_type::difference_type difference_type; 149 typedef typename _Rep_type::reverse_iterator reverse_iterator; 150 typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator; 151 152 // [23.3.2] construct/copy/destroy 153 // (get_allocator() is also listed in this section) 154 /** 155 * @brief Default constructor creates no elements. 156 */ 157 multimap() 158 : _M_t() { } 159 160 /** 161 * @brief Creates a %multimap with no elements. 162 * @param __comp A comparison object. 163 * @param __a An allocator object. 164 */ 165 explicit 166 multimap(const _Compare& __comp, 167 const allocator_type& __a = allocator_type()) 168 : _M_t(__comp, _Pair_alloc_type(__a)) { } 169 170 /** 171 * @brief %Multimap copy constructor. 172 * @param __x A %multimap of identical element and allocator types. 173 * 174 * The newly-created %multimap uses a copy of the allocation object 175 * used by @a __x. 176 */ 177 multimap(const multimap& __x) 178 : _M_t(__x._M_t) { } 179 180 #if __cplusplus >= 201103L 181 /** 182 * @brief %Multimap move constructor. 183 * @param __x A %multimap of identical element and allocator types. 184 * 185 * The newly-created %multimap contains the exact contents of @a __x. 186 * The contents of @a __x are a valid, but unspecified %multimap. 187 */ 188 multimap(multimap&& __x) 189 noexcept(is_nothrow_copy_constructible<_Compare>::value) 190 : _M_t(std::move(__x._M_t)) { } 191 192 /** 193 * @brief Builds a %multimap from an initializer_list. 194 * @param __l An initializer_list. 195 * @param __comp A comparison functor. 196 * @param __a An allocator object. 197 * 198 * Create a %multimap consisting of copies of the elements from 199 * the initializer_list. This is linear in N if the list is already 200 * sorted, and NlogN otherwise (where N is @a __l.size()). 201 */ 202 multimap(initializer_list<value_type> __l, 203 const _Compare& __comp = _Compare(), 204 const allocator_type& __a = allocator_type()) 205 : _M_t(__comp, _Pair_alloc_type(__a)) 206 { _M_t._M_insert_equal(__l.begin(), __l.end()); } 207 #endif 208 209 /** 210 * @brief Builds a %multimap from a range. 211 * @param __first An input iterator. 212 * @param __last An input iterator. 213 * 214 * Create a %multimap consisting of copies of the elements from 215 * [__first,__last). This is linear in N if the range is already sorted, 216 * and NlogN otherwise (where N is distance(__first,__last)). 217 */ 218 template<typename _InputIterator> 219 multimap(_InputIterator __first, _InputIterator __last) 220 : _M_t() 221 { _M_t._M_insert_equal(__first, __last); } 222 223 /** 224 * @brief Builds a %multimap from a range. 225 * @param __first An input iterator. 226 * @param __last An input iterator. 227 * @param __comp A comparison functor. 228 * @param __a An allocator object. 229 * 230 * Create a %multimap consisting of copies of the elements from 231 * [__first,__last). This is linear in N if the range is already sorted, 232 * and NlogN otherwise (where N is distance(__first,__last)). 233 */ 234 template<typename _InputIterator> 235 multimap(_InputIterator __first, _InputIterator __last, 236 const _Compare& __comp, 237 const allocator_type& __a = allocator_type()) 238 : _M_t(__comp, _Pair_alloc_type(__a)) 239 { _M_t._M_insert_equal(__first, __last); } 240 241 // FIXME There is no dtor declared, but we should have something generated 242 // by Doxygen. I don't know what tags to add to this paragraph to make 243 // that happen: 244 /** 245 * The dtor only erases the elements, and note that if the elements 246 * themselves are pointers, the pointed-to memory is not touched in any 247 * way. Managing the pointer is the user's responsibility. 248 */ 249 250 /** 251 * @brief %Multimap assignment operator. 252 * @param __x A %multimap of identical element and allocator types. 253 * 254 * All the elements of @a __x are copied, but unlike the copy 255 * constructor, the allocator object is not copied. 256 */ 257 multimap& 258 operator=(const multimap& __x) 259 { 260 _M_t = __x._M_t; 261 return *this; 262 } 263 264 #if __cplusplus >= 201103L 265 /** 266 * @brief %Multimap move assignment operator. 267 * @param __x A %multimap of identical element and allocator types. 268 * 269 * The contents of @a __x are moved into this multimap (without copying). 270 * @a __x is a valid, but unspecified multimap. 271 */ 272 multimap& 273 operator=(multimap&& __x) 274 { 275 // NB: DR 1204. 276 // NB: DR 675. 277 this->clear(); 278 this->swap(__x); 279 return *this; 280 } 281 282 /** 283 * @brief %Multimap list assignment operator. 284 * @param __l An initializer_list. 285 * 286 * This function fills a %multimap with copies of the elements 287 * in the initializer list @a __l. 288 * 289 * Note that the assignment completely changes the %multimap and 290 * that the resulting %multimap's size is the same as the number 291 * of elements assigned. Old data may be lost. 292 */ 293 multimap& 294 operator=(initializer_list<value_type> __l) 295 { 296 this->clear(); 297 this->insert(__l.begin(), __l.end()); 298 return *this; 299 } 300 #endif 301 302 /// Get a copy of the memory allocation object. 303 allocator_type 304 get_allocator() const _GLIBCXX_NOEXCEPT 305 { return allocator_type(_M_t.get_allocator()); } 306 307 // iterators 308 /** 309 * Returns a read/write iterator that points to the first pair in the 310 * %multimap. Iteration is done in ascending order according to the 311 * keys. 312 */ 313 iterator 314 begin() _GLIBCXX_NOEXCEPT 315 { return _M_t.begin(); } 316 317 /** 318 * Returns a read-only (constant) iterator that points to the first pair 319 * in the %multimap. Iteration is done in ascending order according to 320 * the keys. 321 */ 322 const_iterator 323 begin() const _GLIBCXX_NOEXCEPT 324 { return _M_t.begin(); } 325 326 /** 327 * Returns a read/write iterator that points one past the last pair in 328 * the %multimap. Iteration is done in ascending order according to the 329 * keys. 330 */ 331 iterator 332 end() _GLIBCXX_NOEXCEPT 333 { return _M_t.end(); } 334 335 /** 336 * Returns a read-only (constant) iterator that points one past the last 337 * pair in the %multimap. Iteration is done in ascending order according 338 * to the keys. 339 */ 340 const_iterator 341 end() const _GLIBCXX_NOEXCEPT 342 { return _M_t.end(); } 343 344 /** 345 * Returns a read/write reverse iterator that points to the last pair in 346 * the %multimap. Iteration is done in descending order according to the 347 * keys. 348 */ 349 reverse_iterator 350 rbegin() _GLIBCXX_NOEXCEPT 351 { return _M_t.rbegin(); } 352 353 /** 354 * Returns a read-only (constant) reverse iterator that points to the 355 * last pair in the %multimap. Iteration is done in descending order 356 * according to the keys. 357 */ 358 const_reverse_iterator 359 rbegin() const _GLIBCXX_NOEXCEPT 360 { return _M_t.rbegin(); } 361 362 /** 363 * Returns a read/write reverse iterator that points to one before the 364 * first pair in the %multimap. Iteration is done in descending order 365 * according to the keys. 366 */ 367 reverse_iterator 368 rend() _GLIBCXX_NOEXCEPT 369 { return _M_t.rend(); } 370 371 /** 372 * Returns a read-only (constant) reverse iterator that points to one 373 * before the first pair in the %multimap. Iteration is done in 374 * descending order according to the keys. 375 */ 376 const_reverse_iterator 377 rend() const _GLIBCXX_NOEXCEPT 378 { return _M_t.rend(); } 379 380 #if __cplusplus >= 201103L 381 /** 382 * Returns a read-only (constant) iterator that points to the first pair 383 * in the %multimap. Iteration is done in ascending order according to 384 * the keys. 385 */ 386 const_iterator 387 cbegin() const noexcept 388 { return _M_t.begin(); } 389 390 /** 391 * Returns a read-only (constant) iterator that points one past the last 392 * pair in the %multimap. Iteration is done in ascending order according 393 * to the keys. 394 */ 395 const_iterator 396 cend() const noexcept 397 { return _M_t.end(); } 398 399 /** 400 * Returns a read-only (constant) reverse iterator that points to the 401 * last pair in the %multimap. Iteration is done in descending order 402 * according to the keys. 403 */ 404 const_reverse_iterator 405 crbegin() const noexcept 406 { return _M_t.rbegin(); } 407 408 /** 409 * Returns a read-only (constant) reverse iterator that points to one 410 * before the first pair in the %multimap. Iteration is done in 411 * descending order according to the keys. 412 */ 413 const_reverse_iterator 414 crend() const noexcept 415 { return _M_t.rend(); } 416 #endif 417 418 // capacity 419 /** Returns true if the %multimap is empty. */ 420 bool 421 empty() const _GLIBCXX_NOEXCEPT 422 { return _M_t.empty(); } 423 424 /** Returns the size of the %multimap. */ 425 size_type 426 size() const _GLIBCXX_NOEXCEPT 427 { return _M_t.size(); } 428 429 /** Returns the maximum size of the %multimap. */ 430 size_type 431 max_size() const _GLIBCXX_NOEXCEPT 432 { return _M_t.max_size(); } 433 434 // modifiers 435 #if __cplusplus >= 201103L 436 /** 437 * @brief Build and insert a std::pair into the %multimap. 438 * 439 * @param __args Arguments used to generate a new pair instance (see 440 * std::piecewise_contruct for passing arguments to each 441 * part of the pair constructor). 442 * 443 * @return An iterator that points to the inserted (key,value) pair. 444 * 445 * This function builds and inserts a (key, value) %pair into the 446 * %multimap. 447 * Contrary to a std::map the %multimap does not rely on unique keys and 448 * thus multiple pairs with the same key can be inserted. 449 * 450 * Insertion requires logarithmic time. 451 */ 452 template<typename... _Args> 453 iterator 454 emplace(_Args&&... __args) 455 { return _M_t._M_emplace_equal(std::forward<_Args>(__args)...); } 456 457 /** 458 * @brief Builds and inserts a std::pair into the %multimap. 459 * 460 * @param __pos An iterator that serves as a hint as to where the pair 461 * should be inserted. 462 * @param __args Arguments used to generate a new pair instance (see 463 * std::piecewise_contruct for passing arguments to each 464 * part of the pair constructor). 465 * @return An iterator that points to the inserted (key,value) pair. 466 * 467 * This function inserts a (key, value) pair into the %multimap. 468 * Contrary to a std::map the %multimap does not rely on unique keys and 469 * thus multiple pairs with the same key can be inserted. 470 * Note that the first parameter is only a hint and can potentially 471 * improve the performance of the insertion process. A bad hint would 472 * cause no gains in efficiency. 473 * 474 * For more on @a hinting, see: 475 * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html 476 * 477 * Insertion requires logarithmic time (if the hint is not taken). 478 */ 479 template<typename... _Args> 480 iterator 481 emplace_hint(const_iterator __pos, _Args&&... __args) 482 { 483 return _M_t._M_emplace_hint_equal(__pos, 484 std::forward<_Args>(__args)...); 485 } 486 #endif 487 488 /** 489 * @brief Inserts a std::pair into the %multimap. 490 * @param __x Pair to be inserted (see std::make_pair for easy creation 491 * of pairs). 492 * @return An iterator that points to the inserted (key,value) pair. 493 * 494 * This function inserts a (key, value) pair into the %multimap. 495 * Contrary to a std::map the %multimap does not rely on unique keys and 496 * thus multiple pairs with the same key can be inserted. 497 * 498 * Insertion requires logarithmic time. 499 */ 500 iterator 501 insert(const value_type& __x) 502 { return _M_t._M_insert_equal(__x); } 503 504 #if __cplusplus >= 201103L 505 template<typename _Pair, typename = typename 506 std::enable_if<std::is_constructible<value_type, 507 _Pair&&>::value>::type> 508 iterator 509 insert(_Pair&& __x) 510 { return _M_t._M_insert_equal(std::forward<_Pair>(__x)); } 511 #endif 512 513 /** 514 * @brief Inserts a std::pair into the %multimap. 515 * @param __position An iterator that serves as a hint as to where the 516 * pair should be inserted. 517 * @param __x Pair to be inserted (see std::make_pair for easy creation 518 * of pairs). 519 * @return An iterator that points to the inserted (key,value) pair. 520 * 521 * This function inserts a (key, value) pair into the %multimap. 522 * Contrary to a std::map the %multimap does not rely on unique keys and 523 * thus multiple pairs with the same key can be inserted. 524 * Note that the first parameter is only a hint and can potentially 525 * improve the performance of the insertion process. A bad hint would 526 * cause no gains in efficiency. 527 * 528 * For more on @a hinting, see: 529 * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html 530 * 531 * Insertion requires logarithmic time (if the hint is not taken). 532 */ 533 iterator 534 #if __cplusplus >= 201103L 535 insert(const_iterator __position, const value_type& __x) 536 #else 537 insert(iterator __position, const value_type& __x) 538 #endif 539 { return _M_t._M_insert_equal_(__position, __x); } 540 541 #if __cplusplus >= 201103L 542 template<typename _Pair, typename = typename 543 std::enable_if<std::is_constructible<value_type, 544 _Pair&&>::value>::type> 545 iterator 546 insert(const_iterator __position, _Pair&& __x) 547 { return _M_t._M_insert_equal_(__position, 548 std::forward<_Pair>(__x)); } 549 #endif 550 551 /** 552 * @brief A template function that attempts to insert a range 553 * of elements. 554 * @param __first Iterator pointing to the start of the range to be 555 * inserted. 556 * @param __last Iterator pointing to the end of the range. 557 * 558 * Complexity similar to that of the range constructor. 559 */ 560 template<typename _InputIterator> 561 void 562 insert(_InputIterator __first, _InputIterator __last) 563 { _M_t._M_insert_equal(__first, __last); } 564 565 #if __cplusplus >= 201103L 566 /** 567 * @brief Attempts to insert a list of std::pairs into the %multimap. 568 * @param __l A std::initializer_list<value_type> of pairs to be 569 * inserted. 570 * 571 * Complexity similar to that of the range constructor. 572 */ 573 void 574 insert(initializer_list<value_type> __l) 575 { this->insert(__l.begin(), __l.end()); } 576 #endif 577 578 #if __cplusplus >= 201103L 579 // _GLIBCXX_RESOLVE_LIB_DEFECTS 580 // DR 130. Associative erase should return an iterator. 581 /** 582 * @brief Erases an element from a %multimap. 583 * @param __position An iterator pointing to the element to be erased. 584 * @return An iterator pointing to the element immediately following 585 * @a position prior to the element being erased. If no such 586 * element exists, end() is returned. 587 * 588 * This function erases an element, pointed to by the given iterator, 589 * from a %multimap. Note that this function only erases the element, 590 * and that if the element is itself a pointer, the pointed-to memory is 591 * not touched in any way. Managing the pointer is the user's 592 * responsibility. 593 */ 594 iterator 595 erase(const_iterator __position) 596 { return _M_t.erase(__position); } 597 598 // LWG 2059. 599 _GLIBCXX_ABI_TAG_CXX11 600 iterator 601 erase(iterator __position) 602 { return _M_t.erase(__position); } 603 #else 604 /** 605 * @brief Erases an element from a %multimap. 606 * @param __position An iterator pointing to the element to be erased. 607 * 608 * This function erases an element, pointed to by the given iterator, 609 * from a %multimap. Note that this function only erases the element, 610 * and that if the element is itself a pointer, the pointed-to memory is 611 * not touched in any way. Managing the pointer is the user's 612 * responsibility. 613 */ 614 void 615 erase(iterator __position) 616 { _M_t.erase(__position); } 617 #endif 618 619 /** 620 * @brief Erases elements according to the provided key. 621 * @param __x Key of element to be erased. 622 * @return The number of elements erased. 623 * 624 * This function erases all elements located by the given key from a 625 * %multimap. 626 * Note that this function only erases the element, and that if 627 * the element is itself a pointer, the pointed-to memory is not touched 628 * in any way. Managing the pointer is the user's responsibility. 629 */ 630 size_type 631 erase(const key_type& __x) 632 { return _M_t.erase(__x); } 633 634 #if __cplusplus >= 201103L 635 // _GLIBCXX_RESOLVE_LIB_DEFECTS 636 // DR 130. Associative erase should return an iterator. 637 /** 638 * @brief Erases a [first,last) range of elements from a %multimap. 639 * @param __first Iterator pointing to the start of the range to be 640 * erased. 641 * @param __last Iterator pointing to the end of the range to be 642 * erased . 643 * @return The iterator @a __last. 644 * 645 * This function erases a sequence of elements from a %multimap. 646 * Note that this function only erases the elements, and that if 647 * the elements themselves are pointers, the pointed-to memory is not 648 * touched in any way. Managing the pointer is the user's 649 * responsibility. 650 */ 651 iterator 652 erase(const_iterator __first, const_iterator __last) 653 { return _M_t.erase(__first, __last); } 654 #else 655 // _GLIBCXX_RESOLVE_LIB_DEFECTS 656 // DR 130. Associative erase should return an iterator. 657 /** 658 * @brief Erases a [first,last) range of elements from a %multimap. 659 * @param __first Iterator pointing to the start of the range to be 660 * erased. 661 * @param __last Iterator pointing to the end of the range to 662 * be erased. 663 * 664 * This function erases a sequence of elements from a %multimap. 665 * Note that this function only erases the elements, and that if 666 * the elements themselves are pointers, the pointed-to memory is not 667 * touched in any way. Managing the pointer is the user's 668 * responsibility. 669 */ 670 void 671 erase(iterator __first, iterator __last) 672 { _M_t.erase(__first, __last); } 673 #endif 674 675 /** 676 * @brief Swaps data with another %multimap. 677 * @param __x A %multimap of the same element and allocator types. 678 * 679 * This exchanges the elements between two multimaps in constant time. 680 * (It is only swapping a pointer, an integer, and an instance of 681 * the @c Compare type (which itself is often stateless and empty), so it 682 * should be quite fast.) 683 * Note that the global std::swap() function is specialized such that 684 * std::swap(m1,m2) will feed to this function. 685 */ 686 void 687 swap(multimap& __x) 688 { _M_t.swap(__x._M_t); } 689 690 /** 691 * Erases all elements in a %multimap. Note that this function only 692 * erases the elements, and that if the elements themselves are pointers, 693 * the pointed-to memory is not touched in any way. Managing the pointer 694 * is the user's responsibility. 695 */ 696 void 697 clear() _GLIBCXX_NOEXCEPT 698 { _M_t.clear(); } 699 700 // observers 701 /** 702 * Returns the key comparison object out of which the %multimap 703 * was constructed. 704 */ 705 key_compare 706 key_comp() const 707 { return _M_t.key_comp(); } 708 709 /** 710 * Returns a value comparison object, built from the key comparison 711 * object out of which the %multimap was constructed. 712 */ 713 value_compare 714 value_comp() const 715 { return value_compare(_M_t.key_comp()); } 716 717 // multimap operations 718 /** 719 * @brief Tries to locate an element in a %multimap. 720 * @param __x Key of (key, value) pair to be located. 721 * @return Iterator pointing to sought-after element, 722 * or end() if not found. 723 * 724 * This function takes a key and tries to locate the element with which 725 * the key matches. If successful the function returns an iterator 726 * pointing to the sought after %pair. If unsuccessful it returns the 727 * past-the-end ( @c end() ) iterator. 728 */ 729 iterator 730 find(const key_type& __x) 731 { return _M_t.find(__x); } 732 733 /** 734 * @brief Tries to locate an element in a %multimap. 735 * @param __x Key of (key, value) pair to be located. 736 * @return Read-only (constant) iterator pointing to sought-after 737 * element, or end() if not found. 738 * 739 * This function takes a key and tries to locate the element with which 740 * the key matches. If successful the function returns a constant 741 * iterator pointing to the sought after %pair. If unsuccessful it 742 * returns the past-the-end ( @c end() ) iterator. 743 */ 744 const_iterator 745 find(const key_type& __x) const 746 { return _M_t.find(__x); } 747 748 /** 749 * @brief Finds the number of elements with given key. 750 * @param __x Key of (key, value) pairs to be located. 751 * @return Number of elements with specified key. 752 */ 753 size_type 754 count(const key_type& __x) const 755 { return _M_t.count(__x); } 756 757 /** 758 * @brief Finds the beginning of a subsequence matching given key. 759 * @param __x Key of (key, value) pair to be located. 760 * @return Iterator pointing to first element equal to or greater 761 * than key, or end(). 762 * 763 * This function returns the first element of a subsequence of elements 764 * that matches the given key. If unsuccessful it returns an iterator 765 * pointing to the first element that has a greater value than given key 766 * or end() if no such element exists. 767 */ 768 iterator 769 lower_bound(const key_type& __x) 770 { return _M_t.lower_bound(__x); } 771 772 /** 773 * @brief Finds the beginning of a subsequence matching given key. 774 * @param __x Key of (key, value) pair to be located. 775 * @return Read-only (constant) iterator pointing to first element 776 * equal to or greater than key, or end(). 777 * 778 * This function returns the first element of a subsequence of 779 * elements that matches the given key. If unsuccessful the 780 * iterator will point to the next greatest element or, if no 781 * such greater element exists, to end(). 782 */ 783 const_iterator 784 lower_bound(const key_type& __x) const 785 { return _M_t.lower_bound(__x); } 786 787 /** 788 * @brief Finds the end of a subsequence matching given key. 789 * @param __x Key of (key, value) pair to be located. 790 * @return Iterator pointing to the first element 791 * greater than key, or end(). 792 */ 793 iterator 794 upper_bound(const key_type& __x) 795 { return _M_t.upper_bound(__x); } 796 797 /** 798 * @brief Finds the end of a subsequence matching given key. 799 * @param __x Key of (key, value) pair to be located. 800 * @return Read-only (constant) iterator pointing to first iterator 801 * greater than key, or end(). 802 */ 803 const_iterator 804 upper_bound(const key_type& __x) const 805 { return _M_t.upper_bound(__x); } 806 807 /** 808 * @brief Finds a subsequence matching given key. 809 * @param __x Key of (key, value) pairs to be located. 810 * @return Pair of iterators that possibly points to the subsequence 811 * matching given key. 812 * 813 * This function is equivalent to 814 * @code 815 * std::make_pair(c.lower_bound(val), 816 * c.upper_bound(val)) 817 * @endcode 818 * (but is faster than making the calls separately). 819 */ 820 std::pair<iterator, iterator> 821 equal_range(const key_type& __x) 822 { return _M_t.equal_range(__x); } 823 824 /** 825 * @brief Finds a subsequence matching given key. 826 * @param __x Key of (key, value) pairs to be located. 827 * @return Pair of read-only (constant) iterators that possibly points 828 * to the subsequence matching given key. 829 * 830 * This function is equivalent to 831 * @code 832 * std::make_pair(c.lower_bound(val), 833 * c.upper_bound(val)) 834 * @endcode 835 * (but is faster than making the calls separately). 836 */ 837 std::pair<const_iterator, const_iterator> 838 equal_range(const key_type& __x) const 839 { return _M_t.equal_range(__x); } 840 841 template<typename _K1, typename _T1, typename _C1, typename _A1> 842 friend bool 843 operator==(const multimap<_K1, _T1, _C1, _A1>&, 844 const multimap<_K1, _T1, _C1, _A1>&); 845 846 template<typename _K1, typename _T1, typename _C1, typename _A1> 847 friend bool 848 operator<(const multimap<_K1, _T1, _C1, _A1>&, 849 const multimap<_K1, _T1, _C1, _A1>&); 850 }; 851 852 /** 853 * @brief Multimap equality comparison. 854 * @param __x A %multimap. 855 * @param __y A %multimap of the same type as @a __x. 856 * @return True iff the size and elements of the maps are equal. 857 * 858 * This is an equivalence relation. It is linear in the size of the 859 * multimaps. Multimaps are considered equivalent if their sizes are equal, 860 * and if corresponding elements compare equal. 861 */ 862 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 863 inline bool 864 operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x, 865 const multimap<_Key, _Tp, _Compare, _Alloc>& __y) 866 { return __x._M_t == __y._M_t; } 867 868 /** 869 * @brief Multimap ordering relation. 870 * @param __x A %multimap. 871 * @param __y A %multimap of the same type as @a __x. 872 * @return True iff @a x is lexicographically less than @a y. 873 * 874 * This is a total ordering relation. It is linear in the size of the 875 * multimaps. The elements must be comparable with @c <. 876 * 877 * See std::lexicographical_compare() for how the determination is made. 878 */ 879 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 880 inline bool 881 operator<(const multimap<_Key, _Tp, _Compare, _Alloc>& __x, 882 const multimap<_Key, _Tp, _Compare, _Alloc>& __y) 883 { return __x._M_t < __y._M_t; } 884 885 /// Based on operator== 886 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 887 inline bool 888 operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x, 889 const multimap<_Key, _Tp, _Compare, _Alloc>& __y) 890 { return !(__x == __y); } 891 892 /// Based on operator< 893 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 894 inline bool 895 operator>(const multimap<_Key, _Tp, _Compare, _Alloc>& __x, 896 const multimap<_Key, _Tp, _Compare, _Alloc>& __y) 897 { return __y < __x; } 898 899 /// Based on operator< 900 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 901 inline bool 902 operator<=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x, 903 const multimap<_Key, _Tp, _Compare, _Alloc>& __y) 904 { return !(__y < __x); } 905 906 /// Based on operator< 907 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 908 inline bool 909 operator>=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x, 910 const multimap<_Key, _Tp, _Compare, _Alloc>& __y) 911 { return !(__x < __y); } 912 913 /// See std::multimap::swap(). 914 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 915 inline void 916 swap(multimap<_Key, _Tp, _Compare, _Alloc>& __x, 917 multimap<_Key, _Tp, _Compare, _Alloc>& __y) 918 { __x.swap(__y); } 919 920 _GLIBCXX_END_NAMESPACE_CONTAINER 921 } // namespace std 922 923 #endif /* _STL_MULTIMAP_H */ 924
