1// Multiset 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 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 66_GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD) 67 68 /** 69 * @brief A standard container made up of elements, which can be retrieved 70 * 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 multiset<Key> the key_type and value_type are Key. 79 * 80 * Multisets support bidirectional iterators. 81 * 82 * @if maint 83 * The private tree data is declared exactly the same way for set and 84 * multiset; the distinction is made entirely in how the tree functions are 85 * called (*_unique versus *_equal, same as the standard). 86 * @endif 87 */ 88 template <class _Key, class _Compare = std::less<_Key>, 89 class _Alloc = std::allocator<_Key> > 90 class multiset 91 { 92 // concept requirements 93 typedef typename _Alloc::value_type _Alloc_value_type; 94 __glibcxx_class_requires(_Key, _SGIAssignableConcept) 95 __glibcxx_class_requires4(_Compare, bool, _Key, _Key, 96 _BinaryFunctionConcept) 97 __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept) 98 99 public: 100 // typedefs: 101 typedef _Key key_type; 102 typedef _Key value_type; 103 typedef _Compare key_compare; 104 typedef _Compare value_compare; 105 typedef _Alloc allocator_type; 106 107 private: 108 /// @if maint This turns a red-black tree into a [multi]set. @endif 109 typedef typename _Alloc::template rebind<_Key>::other _Key_alloc_type; 110 111 typedef _Rb_tree<key_type, value_type, _Identity<value_type>, 112 key_compare, _Key_alloc_type> _Rep_type; 113 /// @if maint The actual tree structure. @endif 114 _Rep_type _M_t; 115 116 public: 117 typedef typename _Key_alloc_type::pointer pointer; 118 typedef typename _Key_alloc_type::const_pointer const_pointer; 119 typedef typename _Key_alloc_type::reference reference; 120 typedef typename _Key_alloc_type::const_reference const_reference; 121 // _GLIBCXX_RESOLVE_LIB_DEFECTS 122 // DR 103. set::iterator is required to be modifiable, 123 // but this allows modification of keys. 124 typedef typename _Rep_type::const_iterator iterator; 125 typedef typename _Rep_type::const_iterator const_iterator; 126 typedef typename _Rep_type::const_reverse_iterator reverse_iterator; 127 typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator; 128 typedef typename _Rep_type::size_type size_type; 129 typedef typename _Rep_type::difference_type difference_type; 130 131 // allocation/deallocation 132 133 /** 134 * @brief Default constructor creates no elements. 135 */ 136 multiset() 137 : _M_t() { } 138 139 explicit 140 multiset(const _Compare& __comp, 141 const allocator_type& __a = allocator_type()) 142 : _M_t(__comp, __a) { } 143 144 /** 145 * @brief Builds a %multiset from a range. 146 * @param first An input iterator. 147 * @param last An input iterator. 148 * 149 * Create a %multiset consisting of copies of the elements from 150 * [first,last). This is linear in N if the range is already sorted, 151 * and NlogN otherwise (where N is distance(first,last)). 152 */ 153 template <class _InputIterator> 154 multiset(_InputIterator __first, _InputIterator __last) 155 : _M_t() 156 { _M_t._M_insert_equal(__first, __last); } 157 158 /** 159 * @brief Builds a %multiset from a range. 160 * @param first An input iterator. 161 * @param last An input iterator. 162 * @param comp A comparison functor. 163 * @param a An allocator object. 164 * 165 * Create a %multiset consisting of copies of the elements from 166 * [first,last). This is linear in N if the range is already sorted, 167 * and NlogN otherwise (where N is distance(first,last)). 168 */ 169 template <class _InputIterator> 170 multiset(_InputIterator __first, _InputIterator __last, 171 const _Compare& __comp, 172 const allocator_type& __a = allocator_type()) 173 : _M_t(__comp, __a) 174 { _M_t._M_insert_equal(__first, __last); } 175 176 /** 177 * @brief %Multiset copy constructor. 178 * @param x A %multiset of identical element and allocator types. 179 * 180 * The newly-created %multiset uses a copy of the allocation object used 181 * by @a x. 182 */ 183 multiset(const multiset& __x) 184 : _M_t(__x._M_t) { } 185 186 /** 187 * @brief %Multiset assignment operator. 188 * @param x A %multiset of identical element and allocator types. 189 * 190 * All the elements of @a x are copied, but unlike the copy constructor, 191 * the allocator object is not copied. 192 */ 193 multiset& 194 operator=(const multiset& __x) 195 { 196 _M_t = __x._M_t; 197 return *this; 198 } 199 200 // accessors: 201 202 /// Returns the comparison object. 203 key_compare 204 key_comp() const 205 { return _M_t.key_comp(); } 206 /// Returns the comparison object. 207 value_compare 208 value_comp() const 209 { return _M_t.key_comp(); } 210 /// Returns the memory allocation object. 211 allocator_type 212 get_allocator() const 213 { return _M_t.get_allocator(); } 214 215 /** 216 * Returns a read/write iterator that points to the first element in the 217 * %multiset. Iteration is done in ascending order according to the 218 * keys. 219 */ 220 iterator 221 begin() const 222 { return _M_t.begin(); } 223 224 /** 225 * Returns a read/write iterator that points one past the last element in 226 * the %multiset. Iteration is done in ascending order according to the 227 * keys. 228 */ 229 iterator 230 end() const 231 { return _M_t.end(); } 232 233 /** 234 * Returns a read/write reverse iterator that points to the last element 235 * in the %multiset. Iteration is done in descending order according to 236 * the keys. 237 */ 238 reverse_iterator 239 rbegin() const 240 { return _M_t.rbegin(); } 241 242 /** 243 * Returns a read/write reverse iterator that points to the last element 244 * in the %multiset. Iteration is done in descending order according to 245 * the keys. 246 */ 247 reverse_iterator 248 rend() const 249 { return _M_t.rend(); } 250 251 /// Returns true if the %set is empty. 252 bool 253 empty() const 254 { return _M_t.empty(); } 255 256 /// Returns the size of the %set. 257 size_type 258 size() const 259 { return _M_t.size(); } 260 261 /// Returns the maximum size of the %set. 262 size_type 263 max_size() const 264 { return _M_t.max_size(); } 265 266 /** 267 * @brief Swaps data with another %multiset. 268 * @param x A %multiset of the same element and allocator types. 269 * 270 * This exchanges the elements between two multisets in constant time. 271 * (It is only swapping a pointer, an integer, and an instance of the @c 272 * Compare type (which itself is often stateless and empty), so it should 273 * be quite fast.) 274 * Note that the global std::swap() function is specialized such that 275 * std::swap(s1,s2) will feed to this function. 276 */ 277 void 278 swap(multiset& __x) 279 { _M_t.swap(__x._M_t); } 280 281 // insert/erase 282 /** 283 * @brief Inserts an element into the %multiset. 284 * @param x Element to be inserted. 285 * @return An iterator that points to the inserted element. 286 * 287 * This function inserts an element into the %multiset. Contrary 288 * to a std::set the %multiset does not rely on unique keys and thus 289 * multiple copies of the same element can be inserted. 290 * 291 * Insertion requires logarithmic time. 292 */ 293 iterator 294 insert(const value_type& __x) 295 { return _M_t._M_insert_equal(__x); } 296 297 /** 298 * @brief Inserts an element into the %multiset. 299 * @param position An iterator that serves as a hint as to where the 300 * element should be inserted. 301 * @param x Element to be inserted. 302 * @return An iterator that points to the inserted element. 303 * 304 * This function inserts an element into the %multiset. Contrary 305 * to a std::set the %multiset does not rely on unique keys and thus 306 * multiple copies of the same element can be inserted. 307 * 308 * Note that the first parameter is only a hint and can potentially 309 * improve the performance of the insertion process. A bad hint would 310 * cause no gains in efficiency. 311 * 312 * See http://gcc.gnu.org/onlinedocs/libstdc++/23_containers/howto.html#4 313 * for more on "hinting". 314 * 315 * Insertion requires logarithmic time (if the hint is not taken). 316 */ 317 iterator 318 insert(iterator __position, const value_type& __x) 319 { return _M_t._M_insert_equal(__position, __x); } 320 321 /** 322 * @brief A template function that attemps to insert a range of elements. 323 * @param first Iterator pointing to the start of the range to be 324 * inserted. 325 * @param last Iterator pointing to the end of the range. 326 * 327 * Complexity similar to that of the range constructor. 328 */ 329 template <class _InputIterator> 330 void 331 insert(_InputIterator __first, _InputIterator __last) 332 { _M_t._M_insert_equal(__first, __last); } 333 334 /** 335 * @brief Erases an element from a %multiset. 336 * @param position An iterator pointing to the element to be erased. 337 * 338 * This function erases an element, pointed to by the given iterator, 339 * from a %multiset. Note that this function only erases the element, 340 * and that if the element is itself a pointer, the pointed-to memory is 341 * not touched in any way. Managing the pointer is the user's 342 * responsibilty. 343 */ 344 void 345 erase(iterator __position) 346 { _M_t.erase(__position); } 347 348 /** 349 * @brief Erases elements according to the provided key. 350 * @param x Key of element to be erased. 351 * @return The number of elements erased. 352 * 353 * This function erases all elements located by the given key from a 354 * %multiset. 355 * Note that this function only erases the element, and that if 356 * the element is itself a pointer, the pointed-to memory is not touched 357 * in any way. Managing the pointer is the user's responsibilty. 358 */ 359 size_type 360 erase(const key_type& __x) 361 { return _M_t.erase(__x); } 362 363 /** 364 * @brief Erases a [first,last) range of elements from a %multiset. 365 * @param first Iterator pointing to the start of the range to be 366 * erased. 367 * @param last Iterator pointing to the end of the range to be erased. 368 * 369 * This function erases a sequence of elements from a %multiset. 370 * Note that this function only erases the elements, and that if 371 * the elements themselves are pointers, the pointed-to memory is not 372 * touched in any way. Managing the pointer is the user's responsibilty. 373 */ 374 void 375 erase(iterator __first, iterator __last) 376 { _M_t.erase(__first, __last); } 377 378 /** 379 * Erases all elements in a %multiset. Note that this function only 380 * erases the elements, and that if the elements themselves are pointers, 381 * the pointed-to memory is not touched in any way. Managing the pointer 382 * is the user's responsibilty. 383 */ 384 void 385 clear() 386 { _M_t.clear(); } 387 388 // multiset operations: 389 390 /** 391 * @brief Finds the number of elements with given key. 392 * @param x Key of elements to be located. 393 * @return Number of elements with specified key. 394 */ 395 size_type 396 count(const key_type& __x) const 397 { return _M_t.count(__x); } 398 399 // _GLIBCXX_RESOLVE_LIB_DEFECTS 400 // 214. set::find() missing const overload 401 //@{ 402 /** 403 * @brief Tries to locate an element in a %set. 404 * @param x Element to be located. 405 * @return Iterator pointing to sought-after element, or end() if not 406 * found. 407 * 408 * This function takes a key and tries to locate the element with which 409 * the key matches. If successful the function returns an iterator 410 * pointing to the sought after element. If unsuccessful it returns the 411 * past-the-end ( @c end() ) iterator. 412 */ 413 iterator 414 find(const key_type& __x) 415 { return _M_t.find(__x); } 416 417 const_iterator 418 find(const key_type& __x) const 419 { return _M_t.find(__x); } 420 //@} 421 422 //@{ 423 /** 424 * @brief Finds the beginning of a subsequence matching given key. 425 * @param x Key to be located. 426 * @return Iterator pointing to first element equal to or greater 427 * than key, or end(). 428 * 429 * This function returns the first element of a subsequence of elements 430 * that matches the given key. If unsuccessful it returns an iterator 431 * pointing to the first element that has a greater value than given key 432 * or end() if no such element exists. 433 */ 434 iterator 435 lower_bound(const key_type& __x) 436 { return _M_t.lower_bound(__x); } 437 438 const_iterator 439 lower_bound(const key_type& __x) const 440 { return _M_t.lower_bound(__x); } 441 //@} 442 443 //@{ 444 /** 445 * @brief Finds the end of a subsequence matching given key. 446 * @param x Key to be located. 447 * @return Iterator pointing to the first element 448 * greater than key, or end(). 449 */ 450 iterator 451 upper_bound(const key_type& __x) 452 { return _M_t.upper_bound(__x); } 453 454 const_iterator 455 upper_bound(const key_type& __x) const 456 { return _M_t.upper_bound(__x); } 457 //@} 458 459 //@{ 460 /** 461 * @brief Finds a subsequence matching given key. 462 * @param x Key to be located. 463 * @return Pair of iterators that possibly points to the subsequence 464 * matching given key. 465 * 466 * This function is equivalent to 467 * @code 468 * std::make_pair(c.lower_bound(val), 469 * c.upper_bound(val)) 470 * @endcode 471 * (but is faster than making the calls separately). 472 * 473 * This function probably only makes sense for multisets. 474 */ 475 std::pair<iterator, iterator> 476 equal_range(const key_type& __x) 477 { return _M_t.equal_range(__x); } 478 479 std::pair<const_iterator, const_iterator> 480 equal_range(const key_type& __x) const 481 { return _M_t.equal_range(__x); } 482 483 template <class _K1, class _C1, class _A1> 484 friend bool 485 operator== (const multiset<_K1, _C1, _A1>&, 486 const multiset<_K1, _C1, _A1>&); 487 488 template <class _K1, class _C1, class _A1> 489 friend bool 490 operator< (const multiset<_K1, _C1, _A1>&, 491 const multiset<_K1, _C1, _A1>&); 492 }; 493 494 /** 495 * @brief Multiset equality comparison. 496 * @param x A %multiset. 497 * @param y A %multiset of the same type as @a x. 498 * @return True iff the size and elements of the multisets are equal. 499 * 500 * This is an equivalence relation. It is linear in the size of the 501 * multisets. 502 * Multisets are considered equivalent if their sizes are equal, and if 503 * corresponding elements compare equal. 504 */ 505 template <class _Key, class _Compare, class _Alloc> 506 inline bool 507 operator==(const multiset<_Key, _Compare, _Alloc>& __x, 508 const multiset<_Key, _Compare, _Alloc>& __y) 509 { return __x._M_t == __y._M_t; } 510 511 /** 512 * @brief Multiset ordering relation. 513 * @param x A %multiset. 514 * @param y A %multiset of the same type as @a x. 515 * @return True iff @a x is lexicographically less than @a y. 516 * 517 * This is a total ordering relation. It is linear in the size of the 518 * maps. The elements must be comparable with @c <. 519 * 520 * See std::lexicographical_compare() for how the determination is made. 521 */ 522 template <class _Key, class _Compare, class _Alloc> 523 inline bool 524 operator<(const multiset<_Key, _Compare, _Alloc>& __x, 525 const multiset<_Key, _Compare, _Alloc>& __y) 526 { return __x._M_t < __y._M_t; } 527 528 /// Returns !(x == y). 529 template <class _Key, class _Compare, class _Alloc> 530 inline bool 531 operator!=(const multiset<_Key, _Compare, _Alloc>& __x, 532 const multiset<_Key, _Compare, _Alloc>& __y) 533 { return !(__x == __y); } 534 535 /// Returns y < x. 536 template <class _Key, class _Compare, class _Alloc> 537 inline bool 538 operator>(const multiset<_Key,_Compare,_Alloc>& __x, 539 const multiset<_Key,_Compare,_Alloc>& __y) 540 { return __y < __x; } 541 542 /// Returns !(y < x) 543 template <class _Key, class _Compare, class _Alloc> 544 inline bool 545 operator<=(const multiset<_Key, _Compare, _Alloc>& __x, 546 const multiset<_Key, _Compare, _Alloc>& __y) 547 { return !(__y < __x); } 548 549 /// Returns !(x < y) 550 template <class _Key, class _Compare, class _Alloc> 551 inline bool 552 operator>=(const multiset<_Key, _Compare, _Alloc>& __x, 553 const multiset<_Key, _Compare, _Alloc>& __y) 554 { return !(__x < __y); } 555 556 /// See std::multiset::swap(). 557 template <class _Key, class _Compare, class _Alloc> 558 inline void 559 swap(multiset<_Key, _Compare, _Alloc>& __x, 560 multiset<_Key, _Compare, _Alloc>& __y) 561 { __x.swap(__y); } 562 563_GLIBCXX_END_NESTED_NAMESPACE 564 565#endif /* _MULTISET_H */ 566