stl_multiset.h revision 132720
1// Multiset implementation -*- C++ -*- 2 3// Copyright (C) 2001, 2002, 2004 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 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_multiset.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 _MULTISET_H 62#define _MULTISET_H 1 63 64#include <bits/concept_check.h> 65 66namespace _GLIBCXX_STD 67{ 68 69 // Forward declaration of operators < and ==, needed for friend declaration. 70 template <class _Key, class _Compare = less<_Key>, 71 class _Alloc = allocator<_Key> > 72 class multiset; 73 74 template <class _Key, class _Compare, class _Alloc> 75 inline bool 76 operator==(const multiset<_Key,_Compare,_Alloc>& __x, 77 const multiset<_Key,_Compare,_Alloc>& __y); 78 79 template <class _Key, class _Compare, class _Alloc> 80 inline bool 81 operator<(const multiset<_Key,_Compare,_Alloc>& __x, 82 const multiset<_Key,_Compare,_Alloc>& __y); 83 84 /** 85 * @brief A standard container made up of elements, which can be retrieved 86 * in logarithmic time. 87 * 88 * @ingroup Containers 89 * @ingroup Assoc_containers 90 * 91 * Meets the requirements of a <a href="tables.html#65">container</a>, a 92 * <a href="tables.html#66">reversible container</a>, and an 93 * <a href="tables.html#69">associative container</a> (using equivalent 94 * keys). For a @c multiset<Key> the key_type and value_type are Key. 95 * 96 * Multisets support bidirectional iterators. 97 * 98 * @if maint 99 * The private tree data is declared exactly the same way for set and 100 * multiset; the distinction is made entirely in how the tree functions are 101 * called (*_unique versus *_equal, same as the standard). 102 * @endif 103 */ 104 template <class _Key, class _Compare, class _Alloc> 105 class multiset 106 { 107 // concept requirements 108 __glibcxx_class_requires(_Key, _SGIAssignableConcept) 109 __glibcxx_class_requires4(_Compare, bool, _Key, _Key, 110 _BinaryFunctionConcept) 111 112 public: 113 // typedefs: 114 typedef _Key key_type; 115 typedef _Key value_type; 116 typedef _Compare key_compare; 117 typedef _Compare value_compare; 118 119 private: 120 /// @if maint This turns a red-black tree into a [multi]set. @endif 121 typedef _Rb_tree<key_type, value_type, 122 _Identity<value_type>, key_compare, _Alloc> _Rep_type; 123 /// @if maint The actual tree structure. @endif 124 _Rep_type _M_t; 125 126 public: 127 typedef typename _Alloc::pointer pointer; 128 typedef typename _Alloc::const_pointer const_pointer; 129 typedef typename _Alloc::reference reference; 130 typedef typename _Alloc::const_reference const_reference; 131 // _GLIBCXX_RESOLVE_LIB_DEFECTS 132 // DR 103. set::iterator is required to be modifiable, 133 // but this allows modification of keys. 134 typedef typename _Rep_type::const_iterator iterator; 135 typedef typename _Rep_type::const_iterator const_iterator; 136 typedef typename _Rep_type::const_reverse_iterator reverse_iterator; 137 typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator; 138 typedef typename _Rep_type::size_type size_type; 139 typedef typename _Rep_type::difference_type difference_type; 140 typedef typename _Rep_type::allocator_type allocator_type; 141 142 // allocation/deallocation 143 144 /** 145 * @brief Default constructor creates no elements. 146 */ 147 multiset() 148 : _M_t(_Compare(), allocator_type()) { } 149 150 explicit 151 multiset(const _Compare& __comp, 152 const allocator_type& __a = allocator_type()) 153 : _M_t(__comp, __a) { } 154 155 /** 156 * @brief Builds a %multiset from a range. 157 * @param first An input iterator. 158 * @param last An input iterator. 159 * 160 * Create a %multiset consisting of copies of the elements from 161 * [first,last). This is linear in N if the range is already sorted, 162 * and NlogN otherwise (where N is distance(first,last)). 163 */ 164 template <class _InputIterator> 165 multiset(_InputIterator __first, _InputIterator __last) 166 : _M_t(_Compare(), allocator_type()) 167 { _M_t.insert_equal(__first, __last); } 168 169 /** 170 * @brief Builds a %multiset from a range. 171 * @param first An input iterator. 172 * @param last An input iterator. 173 * @param comp A comparison functor. 174 * @param a An allocator object. 175 * 176 * Create a %multiset consisting of copies of the elements from 177 * [first,last). This is linear in N if the range is already sorted, 178 * and NlogN otherwise (where N is distance(first,last)). 179 */ 180 template <class _InputIterator> 181 multiset(_InputIterator __first, _InputIterator __last, 182 const _Compare& __comp, 183 const allocator_type& __a = allocator_type()) 184 : _M_t(__comp, __a) 185 { _M_t.insert_equal(__first, __last); } 186 187 /** 188 * @brief %Multiset copy constructor. 189 * @param x A %multiset of identical element and allocator types. 190 * 191 * The newly-created %multiset uses a copy of the allocation object used 192 * by @a x. 193 */ 194 multiset(const multiset<_Key,_Compare,_Alloc>& __x) 195 : _M_t(__x._M_t) { } 196 197 /** 198 * @brief %Multiset assignment operator. 199 * @param x A %multiset of identical element and allocator types. 200 * 201 * All the elements of @a x are copied, but unlike the copy constructor, 202 * the allocator object is not copied. 203 */ 204 multiset<_Key,_Compare,_Alloc>& 205 operator=(const multiset<_Key,_Compare,_Alloc>& __x) 206 { 207 _M_t = __x._M_t; 208 return *this; 209 } 210 211 // accessors: 212 213 /// Returns the comparison object. 214 key_compare 215 key_comp() const 216 { return _M_t.key_comp(); } 217 /// Returns the comparison object. 218 value_compare 219 value_comp() const 220 { return _M_t.key_comp(); } 221 /// Returns the memory allocation object. 222 allocator_type 223 get_allocator() const 224 { return _M_t.get_allocator(); } 225 226 /** 227 * Returns a read/write iterator that points to the first element in the 228 * %multiset. Iteration is done in ascending order according to the 229 * keys. 230 */ 231 iterator 232 begin() const 233 { return _M_t.begin(); } 234 235 /** 236 * Returns a read/write iterator that points one past the last element in 237 * the %multiset. Iteration is done in ascending order according to the 238 * keys. 239 */ 240 iterator 241 end() const 242 { return _M_t.end(); } 243 244 /** 245 * Returns a read/write reverse iterator that points to the last element 246 * in the %multiset. Iteration is done in descending order according to 247 * the keys. 248 */ 249 reverse_iterator 250 rbegin() const 251 { return _M_t.rbegin(); } 252 253 /** 254 * Returns a read/write reverse iterator that points to the last element 255 * in the %multiset. Iteration is done in descending order according to 256 * the keys. 257 */ 258 reverse_iterator 259 rend() const 260 { return _M_t.rend(); } 261 262 /// Returns true if the %set is empty. 263 bool 264 empty() const 265 { return _M_t.empty(); } 266 267 /// Returns the size of the %set. 268 size_type 269 size() const 270 { return _M_t.size(); } 271 272 /// Returns the maximum size of the %set. 273 size_type 274 max_size() const 275 { return _M_t.max_size(); } 276 277 /** 278 * @brief Swaps data with another %multiset. 279 * @param x A %multiset of the same element and allocator types. 280 * 281 * This exchanges the elements between two multisets in constant time. 282 * (It is only swapping a pointer, an integer, and an instance of the @c 283 * Compare type (which itself is often stateless and empty), so it should 284 * be quite fast.) 285 * Note that the global std::swap() function is specialized such that 286 * std::swap(s1,s2) will feed to this function. 287 */ 288 void 289 swap(multiset<_Key,_Compare,_Alloc>& __x) 290 { _M_t.swap(__x._M_t); } 291 292 // insert/erase 293 /** 294 * @brief Inserts an element into the %multiset. 295 * @param x Element to be inserted. 296 * @return An iterator that points to the inserted element. 297 * 298 * This function inserts an element into the %multiset. Contrary 299 * to a std::set the %multiset does not rely on unique keys and thus 300 * multiple copies of the same element can be inserted. 301 * 302 * Insertion requires logarithmic time. 303 */ 304 iterator 305 insert(const value_type& __x) 306 { return _M_t.insert_equal(__x); } 307 308 /** 309 * @brief Inserts an element into the %multiset. 310 * @param position An iterator that serves as a hint as to where the 311 * element should be inserted. 312 * @param x Element to be inserted. 313 * @return An iterator that points to the inserted element. 314 * 315 * This function inserts an element into the %multiset. Contrary 316 * to a std::set the %multiset does not rely on unique keys and thus 317 * multiple copies of the same element can be inserted. 318 * 319 * Note that the first parameter is only a hint and can potentially 320 * improve the performance of the insertion process. A bad hint would 321 * cause no gains in efficiency. 322 * 323 * See http://gcc.gnu.org/onlinedocs/libstdc++/23_containers/howto.html#4 324 * for more on "hinting". 325 * 326 * Insertion requires logarithmic time (if the hint is not taken). 327 */ 328 iterator 329 insert(iterator __position, const value_type& __x) 330 { 331 typedef typename _Rep_type::iterator _Rep_iterator; 332 return _M_t.insert_equal((_Rep_iterator&)__position, __x); 333 } 334 335 /** 336 * @brief A template function that attemps to insert a range of elements. 337 * @param first Iterator pointing to the start of the range to be 338 * inserted. 339 * @param last Iterator pointing to the end of the range. 340 * 341 * Complexity similar to that of the range constructor. 342 */ 343 template <class _InputIterator> 344 void 345 insert(_InputIterator __first, _InputIterator __last) 346 { _M_t.insert_equal(__first, __last); } 347 348 /** 349 * @brief Erases an element from a %multiset. 350 * @param position An iterator pointing to the element to be erased. 351 * 352 * This function erases an element, pointed to by the given iterator, 353 * from a %multiset. Note that this function only erases the element, 354 * and that if the element is itself a pointer, the pointed-to memory is 355 * not touched in any way. Managing the pointer is the user's 356 * responsibilty. 357 */ 358 void 359 erase(iterator __position) 360 { 361 typedef typename _Rep_type::iterator _Rep_iterator; 362 _M_t.erase((_Rep_iterator&)__position); 363 } 364 365 /** 366 * @brief Erases elements according to the provided key. 367 * @param x Key of element to be erased. 368 * @return The number of elements erased. 369 * 370 * This function erases all elements located by the given key from a 371 * %multiset. 372 * Note that this function only erases the element, and that if 373 * the element is itself a pointer, the pointed-to memory is not touched 374 * in any way. Managing the pointer is the user's responsibilty. 375 */ 376 size_type 377 erase(const key_type& __x) 378 { return _M_t.erase(__x); } 379 380 /** 381 * @brief Erases a [first,last) range of elements from a %multiset. 382 * @param first Iterator pointing to the start of the range to be 383 * erased. 384 * @param last Iterator pointing to the end of the range to be erased. 385 * 386 * This function erases a sequence of elements from a %multiset. 387 * Note that this function only erases the elements, and that if 388 * the elements themselves are pointers, the pointed-to memory is not 389 * touched in any way. Managing the pointer is the user's responsibilty. 390 */ 391 void 392 erase(iterator __first, iterator __last) 393 { 394 typedef typename _Rep_type::iterator _Rep_iterator; 395 _M_t.erase((_Rep_iterator&)__first, (_Rep_iterator&)__last); 396 } 397 398 /** 399 * Erases all elements in a %multiset. Note that this function only 400 * erases the elements, and that if the elements themselves are pointers, 401 * the pointed-to memory is not touched in any way. Managing the pointer 402 * is the user's responsibilty. 403 */ 404 void 405 clear() 406 { _M_t.clear(); } 407 408 // multiset operations: 409 410 /** 411 * @brief Finds the number of elements with given key. 412 * @param x Key of elements to be located. 413 * @return Number of elements with specified key. 414 */ 415 size_type 416 count(const key_type& __x) const 417 { return _M_t.count(__x); } 418 419 // _GLIBCXX_RESOLVE_LIB_DEFECTS 420 // 214. set::find() missing const overload 421 //@{ 422 /** 423 * @brief Tries to locate an element in a %set. 424 * @param x Element to be located. 425 * @return Iterator pointing to sought-after element, or end() if not 426 * found. 427 * 428 * This function takes a key and tries to locate the element with which 429 * the key matches. If successful the function returns an iterator 430 * pointing to the sought after element. If unsuccessful it returns the 431 * past-the-end ( @c end() ) iterator. 432 */ 433 iterator 434 find(const key_type& __x) 435 { return _M_t.find(__x); } 436 437 const_iterator 438 find(const key_type& __x) const 439 { return _M_t.find(__x); } 440 //@} 441 442 //@{ 443 /** 444 * @brief Finds the beginning of a subsequence matching given key. 445 * @param x Key to be located. 446 * @return Iterator pointing to first element equal to or greater 447 * than key, or end(). 448 * 449 * This function returns the first element of a subsequence of elements 450 * that matches the given key. If unsuccessful it returns an iterator 451 * pointing to the first element that has a greater value than given key 452 * or end() if no such element exists. 453 */ 454 iterator 455 lower_bound(const key_type& __x) 456 { return _M_t.lower_bound(__x); } 457 458 const_iterator 459 lower_bound(const key_type& __x) const 460 { return _M_t.lower_bound(__x); } 461 //@} 462 463 //@{ 464 /** 465 * @brief Finds the end of a subsequence matching given key. 466 * @param x Key to be located. 467 * @return Iterator pointing to the first element 468 * greater than key, or end(). 469 */ 470 iterator 471 upper_bound(const key_type& __x) 472 { return _M_t.upper_bound(__x); } 473 474 const_iterator 475 upper_bound(const key_type& __x) const 476 { return _M_t.upper_bound(__x); } 477 //@} 478 479 //@{ 480 /** 481 * @brief Finds a subsequence matching given key. 482 * @param x Key to be located. 483 * @return Pair of iterators that possibly points to the subsequence 484 * matching given key. 485 * 486 * This function is equivalent to 487 * @code 488 * std::make_pair(c.lower_bound(val), 489 * c.upper_bound(val)) 490 * @endcode 491 * (but is faster than making the calls separately). 492 * 493 * This function probably only makes sense for multisets. 494 */ 495 pair<iterator,iterator> 496 equal_range(const key_type& __x) 497 { return _M_t.equal_range(__x); } 498 499 pair<const_iterator,const_iterator> 500 equal_range(const key_type& __x) const 501 { return _M_t.equal_range(__x); } 502 503 template <class _K1, class _C1, class _A1> 504 friend bool 505 operator== (const multiset<_K1,_C1,_A1>&, 506 const multiset<_K1,_C1,_A1>&); 507 508 template <class _K1, class _C1, class _A1> 509 friend bool 510 operator< (const multiset<_K1,_C1,_A1>&, 511 const multiset<_K1,_C1,_A1>&); 512 }; 513 514 /** 515 * @brief Multiset equality comparison. 516 * @param x A %multiset. 517 * @param y A %multiset of the same type as @a x. 518 * @return True iff the size and elements of the multisets are equal. 519 * 520 * This is an equivalence relation. It is linear in the size of the 521 * multisets. 522 * Multisets are considered equivalent if their sizes are equal, and if 523 * corresponding elements compare equal. 524 */ 525 template <class _Key, class _Compare, class _Alloc> 526 inline bool 527 operator==(const multiset<_Key,_Compare,_Alloc>& __x, 528 const multiset<_Key,_Compare,_Alloc>& __y) 529 { return __x._M_t == __y._M_t; } 530 531 /** 532 * @brief Multiset ordering relation. 533 * @param x A %multiset. 534 * @param y A %multiset of the same type as @a x. 535 * @return True iff @a x is lexicographically less than @a y. 536 * 537 * This is a total ordering relation. It is linear in the size of the 538 * maps. The elements must be comparable with @c <. 539 * 540 * See std::lexicographical_compare() for how the determination is made. 541 */ 542 template <class _Key, class _Compare, class _Alloc> 543 inline bool 544 operator<(const multiset<_Key,_Compare,_Alloc>& __x, 545 const multiset<_Key,_Compare,_Alloc>& __y) 546 { return __x._M_t < __y._M_t; } 547 548 /// Returns !(x == y). 549 template <class _Key, class _Compare, class _Alloc> 550 inline bool 551 operator!=(const multiset<_Key,_Compare,_Alloc>& __x, 552 const multiset<_Key,_Compare,_Alloc>& __y) 553 { return !(__x == __y); } 554 555 /// Returns y < x. 556 template <class _Key, class _Compare, class _Alloc> 557 inline bool 558 operator>(const multiset<_Key,_Compare,_Alloc>& __x, 559 const multiset<_Key,_Compare,_Alloc>& __y) 560 { return __y < __x; } 561 562 /// Returns !(y < x) 563 template <class _Key, class _Compare, class _Alloc> 564 inline bool 565 operator<=(const multiset<_Key,_Compare,_Alloc>& __x, 566 const multiset<_Key,_Compare,_Alloc>& __y) 567 { return !(__y < __x); } 568 569 /// Returns !(x < y) 570 template <class _Key, class _Compare, class _Alloc> 571 inline bool 572 operator>=(const multiset<_Key,_Compare,_Alloc>& __x, 573 const multiset<_Key,_Compare,_Alloc>& __y) 574 { return !(__x < __y); } 575 576 /// See std::multiset::swap(). 577 template <class _Key, class _Compare, class _Alloc> 578 inline void 579 swap(multiset<_Key,_Compare,_Alloc>& __x, 580 multiset<_Key,_Compare,_Alloc>& __y) 581 { __x.swap(__y); } 582 583} // namespace std 584 585#endif /* _MULTISET_H */ 586