1// Set 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_set.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 _SET_H 62#define _SET_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 unique keys, which can be 70 * retrieved 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 unique keys). 78 * 79 * Sets support bidirectional iterators. 80 * 81 * @param Key Type of key objects. 82 * @param Compare Comparison function object type, defaults to less<Key>. 83 * @param Alloc Allocator type, defaults to allocator<Key>. 84 * 85 * @if maint 86 * The private tree data is declared exactly the same way for set and 87 * multiset; the distinction is made entirely in how the tree functions are 88 * called (*_unique versus *_equal, same as the standard). 89 * @endif 90 */ 91 template<class _Key, class _Compare = std::less<_Key>, 92 class _Alloc = std::allocator<_Key> > 93 class set 94 { 95 // concept requirements 96 typedef typename _Alloc::value_type _Alloc_value_type; 97 __glibcxx_class_requires(_Key, _SGIAssignableConcept) 98 __glibcxx_class_requires4(_Compare, bool, _Key, _Key, 99 _BinaryFunctionConcept) 100 __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept) 101 102 public: 103 // typedefs: 104 //@{ 105 /// Public typedefs. 106 typedef _Key key_type; 107 typedef _Key value_type; 108 typedef _Compare key_compare; 109 typedef _Compare value_compare; 110 typedef _Alloc allocator_type; 111 //@} 112 113 private: 114 typedef typename _Alloc::template rebind<_Key>::other _Key_alloc_type; 115 116 typedef _Rb_tree<key_type, value_type, _Identity<value_type>, 117 key_compare, _Key_alloc_type> _Rep_type; 118 _Rep_type _M_t; // red-black tree representing set 119 120 public: 121 //@{ 122 /// Iterator-related typedefs. 123 typedef typename _Key_alloc_type::pointer pointer; 124 typedef typename _Key_alloc_type::const_pointer const_pointer; 125 typedef typename _Key_alloc_type::reference reference; 126 typedef typename _Key_alloc_type::const_reference const_reference; 127 // _GLIBCXX_RESOLVE_LIB_DEFECTS 128 // DR 103. set::iterator is required to be modifiable, 129 // but this allows modification of keys. 130 typedef typename _Rep_type::const_iterator iterator; 131 typedef typename _Rep_type::const_iterator const_iterator; 132 typedef typename _Rep_type::const_reverse_iterator reverse_iterator; 133 typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator; 134 typedef typename _Rep_type::size_type size_type; 135 typedef typename _Rep_type::difference_type difference_type; 136 //@} 137 138 // allocation/deallocation 139 /// Default constructor creates no elements. 140 set() 141 : _M_t() { } 142 143 /** 144 * @brief Default constructor creates no elements. 145 * 146 * @param comp Comparator to use. 147 * @param a Allocator to use. 148 */ 149 explicit 150 set(const _Compare& __comp, 151 const allocator_type& __a = allocator_type()) 152 : _M_t(__comp, __a) {} 153 154 /** 155 * @brief Builds a %set from a range. 156 * @param first An input iterator. 157 * @param last An input iterator. 158 * 159 * Create a %set consisting of copies of the elements from [first,last). 160 * This is linear in N if the range is already sorted, and NlogN 161 * otherwise (where N is distance(first,last)). 162 */ 163 template<class _InputIterator> 164 set(_InputIterator __first, _InputIterator __last) 165 : _M_t() 166 { _M_t._M_insert_unique(__first, __last); } 167 168 /** 169 * @brief Builds a %set from a range. 170 * @param first An input iterator. 171 * @param last An input iterator. 172 * @param comp A comparison functor. 173 * @param a An allocator object. 174 * 175 * Create a %set consisting of copies of the elements from [first,last). 176 * This is linear in N if the range is already sorted, and NlogN 177 * otherwise (where N is distance(first,last)). 178 */ 179 template<class _InputIterator> 180 set(_InputIterator __first, _InputIterator __last, 181 const _Compare& __comp, 182 const allocator_type& __a = allocator_type()) 183 : _M_t(__comp, __a) 184 { _M_t._M_insert_unique(__first, __last); } 185 186 /** 187 * @brief Set copy constructor. 188 * @param x A %set of identical element and allocator types. 189 * 190 * The newly-created %set uses a copy of the allocation object used 191 * by @a x. 192 */ 193 set(const set& __x) 194 : _M_t(__x._M_t) { } 195 196 /** 197 * @brief Set assignment operator. 198 * @param x A %set of identical element and allocator types. 199 * 200 * All the elements of @a x are copied, but unlike the copy constructor, 201 * the allocator object is not copied. 202 */ 203 set& 204 operator=(const set& __x) 205 { 206 _M_t = __x._M_t; 207 return *this; 208 } 209 210 // accessors: 211 212 /// Returns the comparison object with which the %set was constructed. 213 key_compare 214 key_comp() const 215 { return _M_t.key_comp(); } 216 /// Returns the comparison object with which the %set was constructed. 217 value_compare 218 value_comp() const 219 { return _M_t.key_comp(); } 220 /// Returns the allocator object with which the %set was constructed. 221 allocator_type 222 get_allocator() const 223 { return _M_t.get_allocator(); } 224 225 /** 226 * Returns a read/write iterator that points to the first element in the 227 * %set. Iteration is done in ascending order according to the keys. 228 */ 229 iterator 230 begin() const 231 { return _M_t.begin(); } 232 233 /** 234 * Returns a read/write iterator that points one past the last element in 235 * the %set. Iteration is done in ascending order according to the keys. 236 */ 237 iterator 238 end() const 239 { return _M_t.end(); } 240 241 /** 242 * Returns a read/write reverse iterator that points to the last element 243 * in the %set. Iteration is done in descending order according to the 244 * keys. 245 */ 246 reverse_iterator 247 rbegin() const 248 { return _M_t.rbegin(); } 249 250 /** 251 * Returns a read-only (constant) reverse iterator that points to the 252 * last pair in the %map. Iteration is done in descending order 253 * according to the keys. 254 */ 255 reverse_iterator 256 rend() const 257 { return _M_t.rend(); } 258 259 /// Returns true if the %set is empty. 260 bool 261 empty() const 262 { return _M_t.empty(); } 263 264 /// Returns the size of the %set. 265 size_type 266 size() const 267 { return _M_t.size(); } 268 269 /// Returns the maximum size of the %set. 270 size_type 271 max_size() const 272 { return _M_t.max_size(); } 273 274 /** 275 * @brief Swaps data with another %set. 276 * @param x A %set of the same element and allocator types. 277 * 278 * This exchanges the elements between two sets in constant time. 279 * (It is only swapping a pointer, an integer, and an instance of 280 * the @c Compare type (which itself is often stateless and empty), so it 281 * should be quite fast.) 282 * Note that the global std::swap() function is specialized such that 283 * std::swap(s1,s2) will feed to this function. 284 */ 285 void 286 swap(set& __x) 287 { _M_t.swap(__x._M_t); } 288 289 // insert/erase 290 /** 291 * @brief Attempts to insert an element into the %set. 292 * @param x Element to be inserted. 293 * @return A pair, of which the first element is an iterator that points 294 * to the possibly inserted element, and the second is a bool 295 * that is true if the element was actually inserted. 296 * 297 * This function attempts to insert an element into the %set. A %set 298 * relies on unique keys and thus an element is only inserted if it is 299 * not already present in the %set. 300 * 301 * Insertion requires logarithmic time. 302 */ 303 std::pair<iterator,bool> 304 insert(const value_type& __x) 305 { 306 std::pair<typename _Rep_type::iterator, bool> __p = 307 _M_t._M_insert_unique(__x); 308 return std::pair<iterator, bool>(__p.first, __p.second); 309 } 310 311 /** 312 * @brief Attempts to insert an element into the %set. 313 * @param position An iterator that serves as a hint as to where the 314 * element should be inserted. 315 * @param x Element to be inserted. 316 * @return An iterator that points to the element with key of @a x (may 317 * or may not be the element passed in). 318 * 319 * This function is not concerned about whether the insertion took place, 320 * and thus does not return a boolean like the single-argument insert() 321 * does. Note that the first parameter is only a hint and can 322 * potentially improve the performance of the insertion process. A bad 323 * hint would cause no gains in efficiency. 324 * 325 * See http://gcc.gnu.org/onlinedocs/libstdc++/23_containers/howto.html#4 326 * for more on "hinting". 327 * 328 * Insertion requires logarithmic time (if the hint is not taken). 329 */ 330 iterator 331 insert(iterator __position, const value_type& __x) 332 { return _M_t._M_insert_unique(__position, __x); } 333 334 /** 335 * @brief A template function that attemps to insert a range of elements. 336 * @param first Iterator pointing to the start of the range to be 337 * inserted. 338 * @param last Iterator pointing to the end of the range. 339 * 340 * Complexity similar to that of the range constructor. 341 */ 342 template<class _InputIterator> 343 void 344 insert(_InputIterator __first, _InputIterator __last) 345 { _M_t._M_insert_unique(__first, __last); } 346 347 /** 348 * @brief Erases an element from a %set. 349 * @param position An iterator pointing to the element to be erased. 350 * 351 * This function erases an element, pointed to by the given iterator, 352 * from a %set. Note that this function only erases the element, and 353 * that if the element is itself a pointer, the pointed-to memory is not 354 * touched in any way. Managing the pointer is the user's responsibilty. 355 */ 356 void 357 erase(iterator __position) 358 { _M_t.erase(__position); } 359 360 /** 361 * @brief Erases elements according to the provided key. 362 * @param x Key of element to be erased. 363 * @return The number of elements erased. 364 * 365 * This function erases all the elements located by the given key from 366 * a %set. 367 * Note that this function only erases the element, and that if 368 * the element is itself a pointer, the pointed-to memory is not touched 369 * in any way. Managing the pointer is the user's responsibilty. 370 */ 371 size_type 372 erase(const key_type& __x) 373 { return _M_t.erase(__x); } 374 375 /** 376 * @brief Erases a [first,last) range of elements from a %set. 377 * @param first Iterator pointing to the start of the range to be 378 * erased. 379 * @param last Iterator pointing to the end of the range to be erased. 380 * 381 * This function erases a sequence of elements from a %set. 382 * Note that this function only erases the element, and that if 383 * the element is itself a pointer, the pointed-to memory is not touched 384 * in any way. Managing the pointer is the user's responsibilty. 385 */ 386 void 387 erase(iterator __first, iterator __last) 388 { _M_t.erase(__first, __last); } 389 390 /** 391 * Erases all elements in a %set. Note that this function only erases 392 * the elements, and that if the elements themselves are pointers, the 393 * pointed-to memory is not touched in any way. Managing the pointer is 394 * the user's responsibilty. 395 */ 396 void 397 clear() 398 { _M_t.clear(); } 399 400 // set operations: 401 402 /** 403 * @brief Finds the number of elements. 404 * @param x Element to located. 405 * @return Number of elements with specified key. 406 * 407 * This function only makes sense for multisets; for set the result will 408 * either be 0 (not present) or 1 (present). 409 */ 410 size_type 411 count(const key_type& __x) const 412 { return _M_t.find(__x) == _M_t.end() ? 0 : 1; } 413 414 // _GLIBCXX_RESOLVE_LIB_DEFECTS 415 // 214. set::find() missing const overload 416 //@{ 417 /** 418 * @brief Tries to locate an element in a %set. 419 * @param x Element to be located. 420 * @return Iterator pointing to sought-after element, or end() if not 421 * found. 422 * 423 * This function takes a key and tries to locate the element with which 424 * the key matches. If successful the function returns an iterator 425 * pointing to the sought after element. If unsuccessful it returns the 426 * past-the-end ( @c end() ) iterator. 427 */ 428 iterator 429 find(const key_type& __x) 430 { return _M_t.find(__x); } 431 432 const_iterator 433 find(const key_type& __x) const 434 { return _M_t.find(__x); } 435 //@} 436 437 //@{ 438 /** 439 * @brief Finds the beginning of a subsequence matching given key. 440 * @param x Key to be located. 441 * @return Iterator pointing to first element equal to or greater 442 * than key, or end(). 443 * 444 * This function returns the first element of a subsequence of elements 445 * that matches the given key. If unsuccessful it returns an iterator 446 * pointing to the first element that has a greater value than given key 447 * or end() if no such element exists. 448 */ 449 iterator 450 lower_bound(const key_type& __x) 451 { return _M_t.lower_bound(__x); } 452 453 const_iterator 454 lower_bound(const key_type& __x) const 455 { return _M_t.lower_bound(__x); } 456 //@} 457 458 //@{ 459 /** 460 * @brief Finds the end of a subsequence matching given key. 461 * @param x Key to be located. 462 * @return Iterator pointing to the first element 463 * greater than key, or end(). 464 */ 465 iterator 466 upper_bound(const key_type& __x) 467 { return _M_t.upper_bound(__x); } 468 469 const_iterator 470 upper_bound(const key_type& __x) const 471 { return _M_t.upper_bound(__x); } 472 //@} 473 474 //@{ 475 /** 476 * @brief Finds a subsequence matching given key. 477 * @param x Key to be located. 478 * @return Pair of iterators that possibly points to the subsequence 479 * matching given key. 480 * 481 * This function is equivalent to 482 * @code 483 * std::make_pair(c.lower_bound(val), 484 * c.upper_bound(val)) 485 * @endcode 486 * (but is faster than making the calls separately). 487 * 488 * This function probably only makes sense for multisets. 489 */ 490 std::pair<iterator, iterator> 491 equal_range(const key_type& __x) 492 { return _M_t.equal_range(__x); } 493 494 std::pair<const_iterator, const_iterator> 495 equal_range(const key_type& __x) const 496 { return _M_t.equal_range(__x); } 497 //@} 498 499 template<class _K1, class _C1, class _A1> 500 friend bool 501 operator== (const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&); 502 503 template<class _K1, class _C1, class _A1> 504 friend bool 505 operator< (const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&); 506 }; 507 508 509 /** 510 * @brief Set equality comparison. 511 * @param x A %set. 512 * @param y A %set of the same type as @a x. 513 * @return True iff the size and elements of the sets are equal. 514 * 515 * This is an equivalence relation. It is linear in the size of the sets. 516 * Sets are considered equivalent if their sizes are equal, and if 517 * corresponding elements compare equal. 518 */ 519 template<class _Key, class _Compare, class _Alloc> 520 inline bool 521 operator==(const set<_Key, _Compare, _Alloc>& __x, 522 const set<_Key, _Compare, _Alloc>& __y) 523 { return __x._M_t == __y._M_t; } 524 525 /** 526 * @brief Set ordering relation. 527 * @param x A %set. 528 * @param y A %set of the same type as @a x. 529 * @return True iff @a x is lexicographically less than @a y. 530 * 531 * This is a total ordering relation. It is linear in the size of the 532 * maps. The elements must be comparable with @c <. 533 * 534 * See std::lexicographical_compare() for how the determination is made. 535 */ 536 template<class _Key, class _Compare, class _Alloc> 537 inline bool 538 operator<(const set<_Key, _Compare, _Alloc>& __x, 539 const set<_Key, _Compare, _Alloc>& __y) 540 { return __x._M_t < __y._M_t; } 541 542 /// Returns !(x == y). 543 template<class _Key, class _Compare, class _Alloc> 544 inline bool 545 operator!=(const set<_Key, _Compare, _Alloc>& __x, 546 const set<_Key, _Compare, _Alloc>& __y) 547 { return !(__x == __y); } 548 549 /// Returns y < x. 550 template<class _Key, class _Compare, class _Alloc> 551 inline bool 552 operator>(const set<_Key, _Compare, _Alloc>& __x, 553 const set<_Key, _Compare, _Alloc>& __y) 554 { return __y < __x; } 555 556 /// Returns !(y < x) 557 template<class _Key, class _Compare, class _Alloc> 558 inline bool 559 operator<=(const set<_Key, _Compare, _Alloc>& __x, 560 const set<_Key, _Compare, _Alloc>& __y) 561 { return !(__y < __x); } 562 563 /// Returns !(x < y) 564 template<class _Key, class _Compare, class _Alloc> 565 inline bool 566 operator>=(const set<_Key, _Compare, _Alloc>& __x, 567 const set<_Key, _Compare, _Alloc>& __y) 568 { return !(__x < __y); } 569 570 /// See std::set::swap(). 571 template<class _Key, class _Compare, class _Alloc> 572 inline void 573 swap(set<_Key, _Compare, _Alloc>& __x, set<_Key, _Compare, _Alloc>& __y) 574 { __x.swap(__y); } 575 576_GLIBCXX_END_NESTED_NAMESPACE 577 578#endif /* _SET_H */ 579