1// Multimap implementation -*- C++ -*- 2 3// Copyright (C) 2001, 2002, 2004, 2005, 2006 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 2, 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// You should have received a copy of the GNU General Public License along 17// with this library; see the file COPYING. If not, write to the Free 18// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 19// USA. 20 21// As a special exception, you may use this file as part of a free software 22// library without restriction. Specifically, if other files instantiate 23// templates or use macros or inline functions from this file, or you compile 24// this file and link it with other files to produce an executable, this 25// file does not by itself cause the resulting executable to be covered by 26// the GNU General Public License. This exception does not however 27// invalidate any other reasons why the executable file might be covered by 28// the GNU General Public License. 29 30/* 31 * 32 * Copyright (c) 1994 33 * Hewlett-Packard Company 34 * 35 * Permission to use, copy, modify, distribute and sell this software 36 * and its documentation for any purpose is hereby granted without fee, 37 * provided that the above copyright notice appear in all copies and 38 * that both that copyright notice and this permission notice appear 39 * in supporting documentation. Hewlett-Packard Company makes no 40 * representations about the suitability of this software for any 41 * purpose. It is provided "as is" without express or implied warranty. 42 * 43 * 44 * Copyright (c) 1996,1997 45 * Silicon Graphics Computer Systems, Inc. 46 * 47 * Permission to use, copy, modify, distribute and sell this software 48 * and its documentation for any purpose is hereby granted without fee, 49 * provided that the above copyright notice appear in all copies and 50 * that both that copyright notice and this permission notice appear 51 * in supporting documentation. Silicon Graphics makes no 52 * representations about the suitability of this software for any 53 * purpose. It is provided "as is" without express or implied warranty. 54 */ 55 56/** @file stl_multimap.h 57 * This is an internal header file, included by other library headers. 58 * You should not attempt to use it directly. 59 */ 60 61#ifndef _MULTIMAP_H 62#define _MULTIMAP_H 1 63 64#include <bits/concept_check.h> 65 66_GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD) 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 Containers 73 * @ingroup Assoc_containers 74 * 75 * Meets the requirements of a <a href="tables.html#65">container</a>, a 76 * <a href="tables.html#66">reversible container</a>, and an 77 * <a href="tables.html#69">associative container</a> (using equivalent 78 * keys). For a @c multimap<Key,T> the key_type is Key, the mapped_type 79 * is T, and the value_type is std::pair<const Key,T>. 80 * 81 * Multimaps support bidirectional iterators. 82 * 83 * @if maint 84 * The private tree data is declared exactly the same way for map and 85 * multimap; the distinction is made entirely in how the tree functions are 86 * called (*_unique versus *_equal, same as the standard). 87 * @endif 88 */ 89 template <typename _Key, typename _Tp, 90 typename _Compare = std::less<_Key>, 91 typename _Alloc = std::allocator<std::pair<const _Key, _Tp> > > 92 class multimap 93 { 94 public: 95 typedef _Key key_type; 96 typedef _Tp mapped_type; 97 typedef std::pair<const _Key, _Tp> value_type; 98 typedef _Compare key_compare; 99 typedef _Alloc allocator_type; 100 101 private: 102 // concept requirements 103 typedef typename _Alloc::value_type _Alloc_value_type; 104 __glibcxx_class_requires(_Tp, _SGIAssignableConcept) 105 __glibcxx_class_requires4(_Compare, bool, _Key, _Key, 106 _BinaryFunctionConcept) 107 __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept) 108 109 public: 110 class value_compare 111 : public std::binary_function<value_type, value_type, bool> 112 { 113 friend class multimap<_Key, _Tp, _Compare, _Alloc>; 114 protected: 115 _Compare comp; 116 117 value_compare(_Compare __c) 118 : comp(__c) { } 119 120 public: 121 bool operator()(const value_type& __x, const value_type& __y) const 122 { return comp(__x.first, __y.first); } 123 }; 124 125 private: 126 /// @if maint This turns a red-black tree into a [multi]map. @endif 127 typedef typename _Alloc::template rebind<value_type>::other 128 _Pair_alloc_type; 129 130 typedef _Rb_tree<key_type, value_type, _Select1st<value_type>, 131 key_compare, _Pair_alloc_type> _Rep_type; 132 /// @if maint The actual tree structure. @endif 133 _Rep_type _M_t; 134 135 public: 136 // many of these are specified differently in ISO, but the following are 137 // "functionally equivalent" 138 typedef typename _Pair_alloc_type::pointer pointer; 139 typedef typename _Pair_alloc_type::const_pointer const_pointer; 140 typedef typename _Pair_alloc_type::reference reference; 141 typedef typename _Pair_alloc_type::const_reference const_reference; 142 typedef typename _Rep_type::iterator iterator; 143 typedef typename _Rep_type::const_iterator const_iterator; 144 typedef typename _Rep_type::size_type size_type; 145 typedef typename _Rep_type::difference_type difference_type; 146 typedef typename _Rep_type::reverse_iterator reverse_iterator; 147 typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator; 148 149 // [23.3.2] construct/copy/destroy 150 // (get_allocator() is also listed in this section) 151 /** 152 * @brief Default constructor creates no elements. 153 */ 154 multimap() 155 : _M_t() { } 156 157 // for some reason this was made a separate function 158 /** 159 * @brief Default constructor creates no elements. 160 */ 161 explicit 162 multimap(const _Compare& __comp, 163 const allocator_type& __a = allocator_type()) 164 : _M_t(__comp, __a) { } 165 166 /** 167 * @brief %Multimap copy constructor. 168 * @param x A %multimap of identical element and allocator types. 169 * 170 * The newly-created %multimap uses a copy of the allocation object used 171 * by @a x. 172 */ 173 multimap(const multimap& __x) 174 : _M_t(__x._M_t) { } 175 176 /** 177 * @brief Builds a %multimap from a range. 178 * @param first An input iterator. 179 * @param last An input iterator. 180 * 181 * Create a %multimap consisting of copies of the elements from 182 * [first,last). This is linear in N if the range is already sorted, 183 * and NlogN otherwise (where N is distance(first,last)). 184 */ 185 template <typename _InputIterator> 186 multimap(_InputIterator __first, _InputIterator __last) 187 : _M_t() 188 { _M_t._M_insert_equal(__first, __last); } 189 190 /** 191 * @brief Builds a %multimap from a range. 192 * @param first An input iterator. 193 * @param last An input iterator. 194 * @param comp A comparison functor. 195 * @param a An allocator object. 196 * 197 * Create a %multimap consisting of copies of the elements from 198 * [first,last). This is linear in N if the range is already sorted, 199 * and NlogN otherwise (where N is distance(first,last)). 200 */ 201 template <typename _InputIterator> 202 multimap(_InputIterator __first, _InputIterator __last, 203 const _Compare& __comp, 204 const allocator_type& __a = allocator_type()) 205 : _M_t(__comp, __a) 206 { _M_t._M_insert_equal(__first, __last); } 207 208 // FIXME There is no dtor declared, but we should have something generated 209 // by Doxygen. I don't know what tags to add to this paragraph to make 210 // that happen: 211 /** 212 * The dtor only erases the elements, and note that if the elements 213 * themselves are pointers, the pointed-to memory is not touched in any 214 * way. Managing the pointer is the user's responsibilty. 215 */ 216 217 /** 218 * @brief %Multimap assignment operator. 219 * @param x A %multimap of identical element and allocator types. 220 * 221 * All the elements of @a x are copied, but unlike the copy constructor, 222 * the allocator object is not copied. 223 */ 224 multimap& 225 operator=(const multimap& __x) 226 { 227 _M_t = __x._M_t; 228 return *this; 229 } 230 231 /// Get a copy of the memory allocation object. 232 allocator_type 233 get_allocator() const 234 { return _M_t.get_allocator(); } 235 236 // iterators 237 /** 238 * Returns a read/write iterator that points to the first pair in the 239 * %multimap. Iteration is done in ascending order according to the 240 * keys. 241 */ 242 iterator 243 begin() 244 { return _M_t.begin(); } 245 246 /** 247 * Returns a read-only (constant) iterator that points to the first pair 248 * in the %multimap. Iteration is done in ascending order according to 249 * the keys. 250 */ 251 const_iterator 252 begin() const 253 { return _M_t.begin(); } 254 255 /** 256 * Returns a read/write iterator that points one past the last pair in 257 * the %multimap. Iteration is done in ascending order according to the 258 * keys. 259 */ 260 iterator 261 end() 262 { return _M_t.end(); } 263 264 /** 265 * Returns a read-only (constant) iterator that points one past the last 266 * pair in the %multimap. Iteration is done in ascending order according 267 * to the keys. 268 */ 269 const_iterator 270 end() const 271 { return _M_t.end(); } 272 273 /** 274 * Returns a read/write reverse iterator that points to the last pair in 275 * the %multimap. Iteration is done in descending order according to the 276 * keys. 277 */ 278 reverse_iterator 279 rbegin() 280 { return _M_t.rbegin(); } 281 282 /** 283 * Returns a read-only (constant) reverse iterator that points to the 284 * last pair in the %multimap. Iteration is done in descending order 285 * according to the keys. 286 */ 287 const_reverse_iterator 288 rbegin() const 289 { return _M_t.rbegin(); } 290 291 /** 292 * Returns a read/write reverse iterator that points to one before the 293 * first pair in the %multimap. Iteration is done in descending order 294 * according to the keys. 295 */ 296 reverse_iterator 297 rend() 298 { return _M_t.rend(); } 299 300 /** 301 * Returns a read-only (constant) reverse iterator that points to one 302 * before the first pair in the %multimap. Iteration is done in 303 * descending order according to the keys. 304 */ 305 const_reverse_iterator 306 rend() const 307 { return _M_t.rend(); } 308 309 // capacity 310 /** Returns true if the %multimap is empty. */ 311 bool 312 empty() const 313 { return _M_t.empty(); } 314 315 /** Returns the size of the %multimap. */ 316 size_type 317 size() const 318 { return _M_t.size(); } 319 320 /** Returns the maximum size of the %multimap. */ 321 size_type 322 max_size() const 323 { return _M_t.max_size(); } 324 325 // modifiers 326 /** 327 * @brief Inserts a std::pair into the %multimap. 328 * @param x Pair to be inserted (see std::make_pair for easy creation 329 * of pairs). 330 * @return An iterator that points to the inserted (key,value) pair. 331 * 332 * This function inserts a (key, value) pair into the %multimap. 333 * Contrary to a std::map the %multimap does not rely on unique keys and 334 * thus multiple pairs with the same key can be inserted. 335 * 336 * Insertion requires logarithmic time. 337 */ 338 iterator 339 insert(const value_type& __x) 340 { return _M_t._M_insert_equal(__x); } 341 342 /** 343 * @brief Inserts a std::pair into the %multimap. 344 * @param position An iterator that serves as a hint as to where the 345 * pair should be inserted. 346 * @param x Pair to be inserted (see std::make_pair for easy creation 347 * of pairs). 348 * @return An iterator that points to the inserted (key,value) pair. 349 * 350 * This function inserts a (key, value) pair into the %multimap. 351 * Contrary to a std::map the %multimap does not rely on unique keys and 352 * thus multiple pairs with the same key can be inserted. 353 * Note that the first parameter is only a hint and can potentially 354 * improve the performance of the insertion process. A bad hint would 355 * cause no gains in efficiency. 356 * 357 * See http://gcc.gnu.org/onlinedocs/libstdc++/23_containers/howto.html#4 358 * for more on "hinting". 359 * 360 * Insertion requires logarithmic time (if the hint is not taken). 361 */ 362 iterator 363 insert(iterator __position, const value_type& __x) 364 { return _M_t._M_insert_equal(__position, __x); } 365 366 /** 367 * @brief A template function that attemps to insert a range of elements. 368 * @param first Iterator pointing to the start of the range to be 369 * inserted. 370 * @param last Iterator pointing to the end of the range. 371 * 372 * Complexity similar to that of the range constructor. 373 */ 374 template <typename _InputIterator> 375 void 376 insert(_InputIterator __first, _InputIterator __last) 377 { _M_t._M_insert_equal(__first, __last); } 378 379 /** 380 * @brief Erases an element from a %multimap. 381 * @param position An iterator pointing to the element to be erased. 382 * 383 * This function erases an element, pointed to by the given iterator, 384 * from a %multimap. Note that this function only erases the element, 385 * and that if the element is itself a pointer, the pointed-to memory is 386 * not touched in any way. Managing the pointer is the user's 387 * responsibilty. 388 */ 389 void 390 erase(iterator __position) 391 { _M_t.erase(__position); } 392 393 /** 394 * @brief Erases elements according to the provided key. 395 * @param x Key of element to be erased. 396 * @return The number of elements erased. 397 * 398 * This function erases all elements located by the given key from a 399 * %multimap. 400 * Note that this function only erases the element, and that if 401 * the element is itself a pointer, the pointed-to memory is not touched 402 * in any way. Managing the pointer is the user's responsibilty. 403 */ 404 size_type 405 erase(const key_type& __x) 406 { return _M_t.erase(__x); } 407 408 /** 409 * @brief Erases a [first,last) range of elements from a %multimap. 410 * @param first Iterator pointing to the start of the range to be 411 * erased. 412 * @param last Iterator pointing to the end of the range to be erased. 413 * 414 * This function erases a sequence of elements from a %multimap. 415 * Note that this function only erases the elements, and that if 416 * the elements themselves are pointers, the pointed-to memory is not 417 * touched in any way. Managing the pointer is the user's responsibilty. 418 */ 419 void 420 erase(iterator __first, iterator __last) 421 { _M_t.erase(__first, __last); } 422 423 /** 424 * @brief Swaps data with another %multimap. 425 * @param x A %multimap of the same element and allocator types. 426 * 427 * This exchanges the elements between two multimaps in constant time. 428 * (It is only swapping a pointer, an integer, and an instance of 429 * the @c Compare type (which itself is often stateless and empty), so it 430 * should be quite fast.) 431 * Note that the global std::swap() function is specialized such that 432 * std::swap(m1,m2) will feed to this function. 433 */ 434 void 435 swap(multimap& __x) 436 { _M_t.swap(__x._M_t); } 437 438 /** 439 * Erases all elements in a %multimap. Note that this function only 440 * erases the elements, and that if the elements themselves are pointers, 441 * the pointed-to memory is not touched in any way. Managing the pointer 442 * is the user's responsibilty. 443 */ 444 void 445 clear() 446 { _M_t.clear(); } 447 448 // observers 449 /** 450 * Returns the key comparison object out of which the %multimap 451 * was constructed. 452 */ 453 key_compare 454 key_comp() const 455 { return _M_t.key_comp(); } 456 457 /** 458 * Returns a value comparison object, built from the key comparison 459 * object out of which the %multimap was constructed. 460 */ 461 value_compare 462 value_comp() const 463 { return value_compare(_M_t.key_comp()); } 464 465 // multimap operations 466 /** 467 * @brief Tries to locate an element in a %multimap. 468 * @param x Key of (key, value) pair to be located. 469 * @return Iterator pointing to sought-after element, 470 * or end() if not found. 471 * 472 * This function takes a key and tries to locate the element with which 473 * the key matches. If successful the function returns an iterator 474 * pointing to the sought after %pair. If unsuccessful it returns the 475 * past-the-end ( @c end() ) iterator. 476 */ 477 iterator 478 find(const key_type& __x) 479 { return _M_t.find(__x); } 480 481 /** 482 * @brief Tries to locate an element in a %multimap. 483 * @param x Key of (key, value) pair to be located. 484 * @return Read-only (constant) iterator pointing to sought-after 485 * element, or end() if not found. 486 * 487 * This function takes a key and tries to locate the element with which 488 * the key matches. If successful the function returns a constant 489 * iterator pointing to the sought after %pair. If unsuccessful it 490 * returns the past-the-end ( @c end() ) iterator. 491 */ 492 const_iterator 493 find(const key_type& __x) const 494 { return _M_t.find(__x); } 495 496 /** 497 * @brief Finds the number of elements with given key. 498 * @param x Key of (key, value) pairs to be located. 499 * @return Number of elements with specified key. 500 */ 501 size_type 502 count(const key_type& __x) const 503 { return _M_t.count(__x); } 504 505 /** 506 * @brief Finds the beginning of a subsequence matching given key. 507 * @param x Key of (key, value) pair to be located. 508 * @return Iterator pointing to first element equal to or greater 509 * than key, or end(). 510 * 511 * This function returns the first element of a subsequence of elements 512 * that matches the given key. If unsuccessful it returns an iterator 513 * pointing to the first element that has a greater value than given key 514 * or end() if no such element exists. 515 */ 516 iterator 517 lower_bound(const key_type& __x) 518 { return _M_t.lower_bound(__x); } 519 520 /** 521 * @brief Finds the beginning of a subsequence matching given key. 522 * @param x Key of (key, value) pair to be located. 523 * @return Read-only (constant) iterator pointing to first element 524 * equal to or greater than key, or end(). 525 * 526 * This function returns the first element of a subsequence of elements 527 * that matches the given key. If unsuccessful the iterator will point 528 * to the next greatest element or, if no such greater element exists, to 529 * end(). 530 */ 531 const_iterator 532 lower_bound(const key_type& __x) const 533 { return _M_t.lower_bound(__x); } 534 535 /** 536 * @brief Finds the end of a subsequence matching given key. 537 * @param x Key of (key, value) pair to be located. 538 * @return Iterator pointing to the first element 539 * greater than key, or end(). 540 */ 541 iterator 542 upper_bound(const key_type& __x) 543 { return _M_t.upper_bound(__x); } 544 545 /** 546 * @brief Finds the end of a subsequence matching given key. 547 * @param x Key of (key, value) pair to be located. 548 * @return Read-only (constant) iterator pointing to first iterator 549 * greater than key, or end(). 550 */ 551 const_iterator 552 upper_bound(const key_type& __x) const 553 { return _M_t.upper_bound(__x); } 554 555 /** 556 * @brief Finds a subsequence matching given key. 557 * @param x Key of (key, value) pairs to be located. 558 * @return Pair of iterators that possibly points to the subsequence 559 * matching given key. 560 * 561 * This function is equivalent to 562 * @code 563 * std::make_pair(c.lower_bound(val), 564 * c.upper_bound(val)) 565 * @endcode 566 * (but is faster than making the calls separately). 567 */ 568 std::pair<iterator, iterator> 569 equal_range(const key_type& __x) 570 { return _M_t.equal_range(__x); } 571 572 /** 573 * @brief Finds a subsequence matching given key. 574 * @param x Key of (key, value) pairs to be located. 575 * @return Pair of read-only (constant) iterators that possibly points 576 * to the subsequence matching given key. 577 * 578 * This function is equivalent to 579 * @code 580 * std::make_pair(c.lower_bound(val), 581 * c.upper_bound(val)) 582 * @endcode 583 * (but is faster than making the calls separately). 584 */ 585 std::pair<const_iterator, const_iterator> 586 equal_range(const key_type& __x) const 587 { return _M_t.equal_range(__x); } 588 589 template <typename _K1, typename _T1, typename _C1, typename _A1> 590 friend bool 591 operator== (const multimap<_K1, _T1, _C1, _A1>&, 592 const multimap<_K1, _T1, _C1, _A1>&); 593 594 template <typename _K1, typename _T1, typename _C1, typename _A1> 595 friend bool 596 operator< (const multimap<_K1, _T1, _C1, _A1>&, 597 const multimap<_K1, _T1, _C1, _A1>&); 598 }; 599 600 /** 601 * @brief Multimap equality comparison. 602 * @param x A %multimap. 603 * @param y A %multimap of the same type as @a x. 604 * @return True iff the size and elements of the maps are equal. 605 * 606 * This is an equivalence relation. It is linear in the size of the 607 * multimaps. Multimaps are considered equivalent if their sizes are equal, 608 * and if corresponding elements compare equal. 609 */ 610 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc> 611 inline bool 612 operator==(const multimap<_Key, _Tp, _Compare, _Alloc>& __x, 613 const multimap<_Key, _Tp, _Compare, _Alloc>& __y) 614 { return __x._M_t == __y._M_t; } 615 616 /** 617 * @brief Multimap ordering relation. 618 * @param x A %multimap. 619 * @param y A %multimap of the same type as @a x. 620 * @return True iff @a x is lexicographically less than @a y. 621 * 622 * This is a total ordering relation. It is linear in the size of the 623 * multimaps. The elements must be comparable with @c <. 624 * 625 * See std::lexicographical_compare() for how the determination is made. 626 */ 627 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc> 628 inline bool 629 operator<(const multimap<_Key, _Tp, _Compare, _Alloc>& __x, 630 const multimap<_Key, _Tp, _Compare, _Alloc>& __y) 631 { return __x._M_t < __y._M_t; } 632 633 /// Based on operator== 634 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc> 635 inline bool 636 operator!=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x, 637 const multimap<_Key, _Tp, _Compare, _Alloc>& __y) 638 { return !(__x == __y); } 639 640 /// Based on operator< 641 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc> 642 inline bool 643 operator>(const multimap<_Key, _Tp, _Compare, _Alloc>& __x, 644 const multimap<_Key, _Tp, _Compare, _Alloc>& __y) 645 { return __y < __x; } 646 647 /// Based on operator< 648 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc> 649 inline bool 650 operator<=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x, 651 const multimap<_Key, _Tp, _Compare, _Alloc>& __y) 652 { return !(__y < __x); } 653 654 /// Based on operator< 655 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc> 656 inline bool 657 operator>=(const multimap<_Key, _Tp, _Compare, _Alloc>& __x, 658 const multimap<_Key, _Tp, _Compare, _Alloc>& __y) 659 { return !(__x < __y); } 660 661 /// See std::multimap::swap(). 662 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc> 663 inline void 664 swap(multimap<_Key, _Tp, _Compare, _Alloc>& __x, 665 multimap<_Key, _Tp, _Compare, _Alloc>& __y) 666 { __x.swap(__y); } 667 668_GLIBCXX_END_NESTED_NAMESPACE 669 670#endif /* _MULTIMAP_H */ 671