1// Set implementation -*- C++ -*- 2 3// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 4// Free Software Foundation, Inc. 5// 6// This file is part of the GNU ISO C++ Library. This library is free 7// software; you can redistribute it and/or modify it under the 8// terms of the GNU General Public License as published by the 9// Free Software Foundation; either version 3, or (at your option) 10// any later version. 11 12// This library is distributed in the hope that it will be useful, 13// but WITHOUT ANY WARRANTY; without even the implied warranty of 14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15// GNU General Public License for more details. 16 17// Under Section 7 of GPL version 3, you are granted additional 18// permissions described in the GCC Runtime Library Exception, version 19// 3.1, as published by the Free Software Foundation. 20 21// You should have received a copy of the GNU General Public License and 22// a copy of the GCC Runtime Library Exception along with this program; 23// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24// <http://www.gnu.org/licenses/>. 25 26/* 27 * 28 * Copyright (c) 1994 29 * Hewlett-Packard Company 30 * 31 * Permission to use, copy, modify, distribute and sell this software 32 * and its documentation for any purpose is hereby granted without fee, 33 * provided that the above copyright notice appear in all copies and 34 * that both that copyright notice and this permission notice appear 35 * in supporting documentation. Hewlett-Packard Company makes no 36 * representations about the suitability of this software for any 37 * purpose. It is provided "as is" without express or implied warranty. 38 * 39 * 40 * Copyright (c) 1996,1997 41 * Silicon Graphics Computer Systems, Inc. 42 * 43 * Permission to use, copy, modify, distribute and sell this software 44 * and its documentation for any purpose is hereby granted without fee, 45 * provided that the above copyright notice appear in all copies and 46 * that both that copyright notice and this permission notice appear 47 * in supporting documentation. Silicon Graphics makes no 48 * representations about the suitability of this software for any 49 * purpose. It is provided "as is" without express or implied warranty. 50 */ 51 52/** @file stl_set.h 53 * This is an internal header file, included by other library headers. 54 * You should not attempt to use it directly. 55 */ 56 57#ifndef _STL_SET_H 58#define _STL_SET_H 1 59 60#include <bits/concept_check.h> 61#include <initializer_list> 62 63_GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D) 64 65 /** 66 * @brief A standard container made up of unique keys, which can be 67 * retrieved in logarithmic time. 68 * 69 * @ingroup associative_containers 70 * 71 * Meets the requirements of a <a href="tables.html#65">container</a>, a 72 * <a href="tables.html#66">reversible container</a>, and an 73 * <a href="tables.html#69">associative container</a> (using unique keys). 74 * 75 * Sets support bidirectional iterators. 76 * 77 * @param Key Type of key objects. 78 * @param Compare Comparison function object type, defaults to less<Key>. 79 * @param Alloc Allocator type, defaults to allocator<Key>. 80 * 81 * The private tree data is declared exactly the same way for set and 82 * multiset; the distinction is made entirely in how the tree functions are 83 * called (*_unique versus *_equal, same as the standard). 84 */ 85 template<typename _Key, typename _Compare = std::less<_Key>, 86 typename _Alloc = std::allocator<_Key> > 87 class set 88 { 89 // concept requirements 90 typedef typename _Alloc::value_type _Alloc_value_type; 91 __glibcxx_class_requires(_Key, _SGIAssignableConcept) 92 __glibcxx_class_requires4(_Compare, bool, _Key, _Key, 93 _BinaryFunctionConcept) 94 __glibcxx_class_requires2(_Key, _Alloc_value_type, _SameTypeConcept) 95 96 public: 97 // typedefs: 98 //@{ 99 /// Public typedefs. 100 typedef _Key key_type; 101 typedef _Key value_type; 102 typedef _Compare key_compare; 103 typedef _Compare value_compare; 104 typedef _Alloc allocator_type; 105 //@} 106 107 private: 108 typedef typename _Alloc::template rebind<_Key>::other _Key_alloc_type; 109 110 typedef _Rb_tree<key_type, value_type, _Identity<value_type>, 111 key_compare, _Key_alloc_type> _Rep_type; 112 _Rep_type _M_t; // Red-black tree representing set. 113 114 public: 115 //@{ 116 /// Iterator-related typedefs. 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 //@} 131 132 // allocation/deallocation 133 /** 134 * @brief Default constructor creates no elements. 135 */ 136 set() 137 : _M_t() { } 138 139 /** 140 * @brief Creates a %set with no elements. 141 * @param comp Comparator to use. 142 * @param a An allocator object. 143 */ 144 explicit 145 set(const _Compare& __comp, 146 const allocator_type& __a = allocator_type()) 147 : _M_t(__comp, __a) { } 148 149 /** 150 * @brief Builds a %set from a range. 151 * @param first An input iterator. 152 * @param last An input iterator. 153 * 154 * Create a %set consisting of copies of the elements from [first,last). 155 * This is linear in N if the range is already sorted, and NlogN 156 * otherwise (where N is distance(first,last)). 157 */ 158 template<typename _InputIterator> 159 set(_InputIterator __first, _InputIterator __last) 160 : _M_t() 161 { _M_t._M_insert_unique(__first, __last); } 162 163 /** 164 * @brief Builds a %set from a range. 165 * @param first An input iterator. 166 * @param last An input iterator. 167 * @param comp A comparison functor. 168 * @param a An allocator object. 169 * 170 * Create a %set consisting of copies of the elements from [first,last). 171 * This is linear in N if the range is already sorted, and NlogN 172 * otherwise (where N is distance(first,last)). 173 */ 174 template<typename _InputIterator> 175 set(_InputIterator __first, _InputIterator __last, 176 const _Compare& __comp, 177 const allocator_type& __a = allocator_type()) 178 : _M_t(__comp, __a) 179 { _M_t._M_insert_unique(__first, __last); } 180 181 /** 182 * @brief %Set copy constructor. 183 * @param x A %set of identical element and allocator types. 184 * 185 * The newly-created %set uses a copy of the allocation object used 186 * by @a x. 187 */ 188 set(const set& __x) 189 : _M_t(__x._M_t) { } 190 191#ifdef __GXX_EXPERIMENTAL_CXX0X__ 192 /** 193 * @brief %Set move constructor 194 * @param x A %set of identical element and allocator types. 195 * 196 * The newly-created %set contains the exact contents of @a x. 197 * The contents of @a x are a valid, but unspecified %set. 198 */ 199 set(set&& __x) 200 : _M_t(std::forward<_Rep_type>(__x._M_t)) { } 201 202 /** 203 * @brief Builds a %set from an initializer_list. 204 * @param l An initializer_list. 205 * @param comp A comparison functor. 206 * @param a An allocator object. 207 * 208 * Create a %set consisting of copies of the elements in the list. 209 * This is linear in N if the list is already sorted, and NlogN 210 * otherwise (where N is @a l.size()). 211 */ 212 set(initializer_list<value_type> __l, 213 const _Compare& __comp = _Compare(), 214 const allocator_type& __a = allocator_type()) 215 : _M_t(__comp, __a) 216 { _M_t._M_insert_unique(__l.begin(), __l.end()); } 217#endif 218 219 /** 220 * @brief %Set assignment operator. 221 * @param x A %set of identical element and allocator types. 222 * 223 * All the elements of @a x are copied, but unlike the copy constructor, 224 * the allocator object is not copied. 225 */ 226 set& 227 operator=(const set& __x) 228 { 229 _M_t = __x._M_t; 230 return *this; 231 } 232 233#ifdef __GXX_EXPERIMENTAL_CXX0X__ 234 /** 235 * @brief %Set move assignment operator. 236 * @param x A %set of identical element and allocator types. 237 * 238 * The contents of @a x are moved into this %set (without copying). 239 * @a x is a valid, but unspecified %set. 240 */ 241 set& 242 operator=(set&& __x) 243 { 244 // NB: DR 1204. 245 // NB: DR 675. 246 this->clear(); 247 this->swap(__x); 248 return *this; 249 } 250 251 /** 252 * @brief %Set list assignment operator. 253 * @param l An initializer_list. 254 * 255 * This function fills a %set with copies of the elements in the 256 * initializer list @a l. 257 * 258 * Note that the assignment completely changes the %set and 259 * that the resulting %set's size is the same as the number 260 * of elements assigned. Old data may be lost. 261 */ 262 set& 263 operator=(initializer_list<value_type> __l) 264 { 265 this->clear(); 266 this->insert(__l.begin(), __l.end()); 267 return *this; 268 } 269#endif 270 271 // accessors: 272 273 /// Returns the comparison object with which the %set was constructed. 274 key_compare 275 key_comp() const 276 { return _M_t.key_comp(); } 277 /// Returns the comparison object with which the %set was constructed. 278 value_compare 279 value_comp() const 280 { return _M_t.key_comp(); } 281 /// Returns the allocator object with which the %set was constructed. 282 allocator_type 283 get_allocator() const 284 { return _M_t.get_allocator(); } 285 286 /** 287 * Returns a read-only (constant) iterator that points to the first 288 * element in the %set. Iteration is done in ascending order according 289 * to the keys. 290 */ 291 iterator 292 begin() const 293 { return _M_t.begin(); } 294 295 /** 296 * Returns a read-only (constant) iterator that points one past the last 297 * element in the %set. Iteration is done in ascending order according 298 * to the keys. 299 */ 300 iterator 301 end() const 302 { return _M_t.end(); } 303 304 /** 305 * Returns a read-only (constant) iterator that points to the last 306 * element in the %set. Iteration is done in descending order according 307 * to the keys. 308 */ 309 reverse_iterator 310 rbegin() const 311 { return _M_t.rbegin(); } 312 313 /** 314 * Returns a read-only (constant) reverse iterator that points to the 315 * last pair in the %set. Iteration is done in descending order 316 * according to the keys. 317 */ 318 reverse_iterator 319 rend() const 320 { return _M_t.rend(); } 321 322#ifdef __GXX_EXPERIMENTAL_CXX0X__ 323 /** 324 * Returns a read-only (constant) iterator that points to the first 325 * element in the %set. Iteration is done in ascending order according 326 * to the keys. 327 */ 328 iterator 329 cbegin() const 330 { return _M_t.begin(); } 331 332 /** 333 * Returns a read-only (constant) iterator that points one past the last 334 * element in the %set. Iteration is done in ascending order according 335 * to the keys. 336 */ 337 iterator 338 cend() const 339 { return _M_t.end(); } 340 341 /** 342 * Returns a read-only (constant) iterator that points to the last 343 * element in the %set. Iteration is done in descending order according 344 * to the keys. 345 */ 346 reverse_iterator 347 crbegin() const 348 { return _M_t.rbegin(); } 349 350 /** 351 * Returns a read-only (constant) reverse iterator that points to the 352 * last pair in the %set. Iteration is done in descending order 353 * according to the keys. 354 */ 355 reverse_iterator 356 crend() const 357 { return _M_t.rend(); } 358#endif 359 360 /// Returns true if the %set is empty. 361 bool 362 empty() const 363 { return _M_t.empty(); } 364 365 /// Returns the size of the %set. 366 size_type 367 size() const 368 { return _M_t.size(); } 369 370 /// Returns the maximum size of the %set. 371 size_type 372 max_size() const 373 { return _M_t.max_size(); } 374 375 /** 376 * @brief Swaps data with another %set. 377 * @param x A %set of the same element and allocator types. 378 * 379 * This exchanges the elements between two sets in constant time. 380 * (It is only swapping a pointer, an integer, and an instance of 381 * the @c Compare type (which itself is often stateless and empty), so it 382 * should be quite fast.) 383 * Note that the global std::swap() function is specialized such that 384 * std::swap(s1,s2) will feed to this function. 385 */ 386 void 387 swap(set& __x) 388 { _M_t.swap(__x._M_t); } 389 390 // insert/erase 391 /** 392 * @brief Attempts to insert an element into the %set. 393 * @param x Element to be inserted. 394 * @return A pair, of which the first element is an iterator that points 395 * to the possibly inserted element, and the second is a bool 396 * that is true if the element was actually inserted. 397 * 398 * This function attempts to insert an element into the %set. A %set 399 * relies on unique keys and thus an element is only inserted if it is 400 * not already present in the %set. 401 * 402 * Insertion requires logarithmic time. 403 */ 404 std::pair<iterator, bool> 405 insert(const value_type& __x) 406 { 407 std::pair<typename _Rep_type::iterator, bool> __p = 408 _M_t._M_insert_unique(__x); 409 return std::pair<iterator, bool>(__p.first, __p.second); 410 } 411 412 /** 413 * @brief Attempts to insert an element into the %set. 414 * @param position An iterator that serves as a hint as to where the 415 * element should be inserted. 416 * @param x Element to be inserted. 417 * @return An iterator that points to the element with key of @a x (may 418 * or may not be the element passed in). 419 * 420 * This function is not concerned about whether the insertion took place, 421 * and thus does not return a boolean like the single-argument insert() 422 * does. Note that the first parameter is only a hint and can 423 * potentially improve the performance of the insertion process. A bad 424 * hint would cause no gains in efficiency. 425 * 426 * For more on @a hinting, see: 427 * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html 428 * 429 * Insertion requires logarithmic time (if the hint is not taken). 430 */ 431 iterator 432 insert(iterator __position, const value_type& __x) 433 { return _M_t._M_insert_unique_(__position, __x); } 434 435 /** 436 * @brief A template function that attempts to insert a range 437 * of elements. 438 * @param first Iterator pointing to the start of the range to be 439 * inserted. 440 * @param last Iterator pointing to the end of the range. 441 * 442 * Complexity similar to that of the range constructor. 443 */ 444 template<typename _InputIterator> 445 void 446 insert(_InputIterator __first, _InputIterator __last) 447 { _M_t._M_insert_unique(__first, __last); } 448 449#ifdef __GXX_EXPERIMENTAL_CXX0X__ 450 /** 451 * @brief Attempts to insert a list of elements into the %set. 452 * @param list A std::initializer_list<value_type> of elements 453 * to be inserted. 454 * 455 * Complexity similar to that of the range constructor. 456 */ 457 void 458 insert(initializer_list<value_type> __l) 459 { this->insert(__l.begin(), __l.end()); } 460#endif 461 462#ifdef __GXX_EXPERIMENTAL_CXX0X__ 463 // _GLIBCXX_RESOLVE_LIB_DEFECTS 464 // DR 130. Associative erase should return an iterator. 465 /** 466 * @brief Erases an element from a %set. 467 * @param position An iterator pointing to the element to be erased. 468 * @return An iterator pointing to the element immediately following 469 * @a position prior to the element being erased. If no such 470 * element exists, end() is returned. 471 * 472 * This function erases an element, pointed to by the given iterator, 473 * from a %set. Note that this function only erases the element, and 474 * that if the element is itself a pointer, the pointed-to memory is not 475 * touched in any way. Managing the pointer is the user's responsibility. 476 */ 477 iterator 478 erase(iterator __position) 479 { return _M_t.erase(__position); } 480#else 481 /** 482 * @brief Erases an element from a %set. 483 * @param position An iterator pointing to the element to be erased. 484 * 485 * This function erases an element, pointed to by the given iterator, 486 * from a %set. Note that this function only erases the element, and 487 * that if the element is itself a pointer, the pointed-to memory is not 488 * touched in any way. Managing the pointer is the user's responsibility. 489 */ 490 void 491 erase(iterator __position) 492 { _M_t.erase(__position); } 493#endif 494 495 /** 496 * @brief Erases elements according to the provided key. 497 * @param x Key of element to be erased. 498 * @return The number of elements erased. 499 * 500 * This function erases all the elements located by the given key from 501 * a %set. 502 * Note that this function only erases the element, and that if 503 * the element is itself a pointer, the pointed-to memory is not touched 504 * in any way. Managing the pointer is the user's responsibility. 505 */ 506 size_type 507 erase(const key_type& __x) 508 { return _M_t.erase(__x); } 509 510#ifdef __GXX_EXPERIMENTAL_CXX0X__ 511 // _GLIBCXX_RESOLVE_LIB_DEFECTS 512 // DR 130. Associative erase should return an iterator. 513 /** 514 * @brief Erases a [first,last) range of elements from a %set. 515 * @param first Iterator pointing to the start of the range to be 516 * erased. 517 * @param last Iterator pointing to the end of the range to be erased. 518 * @return The iterator @a last. 519 * 520 * This function erases a sequence of elements from a %set. 521 * Note that this function only erases the element, and that if 522 * the element is itself a pointer, the pointed-to memory is not touched 523 * in any way. Managing the pointer is the user's responsibility. 524 */ 525 iterator 526 erase(iterator __first, iterator __last) 527 { return _M_t.erase(__first, __last); } 528#else 529 /** 530 * @brief Erases a [first,last) range of elements from a %set. 531 * @param first Iterator pointing to the start of the range to be 532 * erased. 533 * @param last Iterator pointing to the end of the range to be erased. 534 * 535 * This function erases a sequence of elements from a %set. 536 * Note that this function only erases the element, and that if 537 * the element is itself a pointer, the pointed-to memory is not touched 538 * in any way. Managing the pointer is the user's responsibility. 539 */ 540 void 541 erase(iterator __first, iterator __last) 542 { _M_t.erase(__first, __last); } 543#endif 544 545 /** 546 * Erases all elements in a %set. Note that this function only erases 547 * the elements, and that if the elements themselves are pointers, the 548 * pointed-to memory is not touched in any way. Managing the pointer is 549 * the user's responsibility. 550 */ 551 void 552 clear() 553 { _M_t.clear(); } 554 555 // set operations: 556 557 /** 558 * @brief Finds the number of elements. 559 * @param x Element to located. 560 * @return Number of elements with specified key. 561 * 562 * This function only makes sense for multisets; for set the result will 563 * either be 0 (not present) or 1 (present). 564 */ 565 size_type 566 count(const key_type& __x) const 567 { return _M_t.find(__x) == _M_t.end() ? 0 : 1; } 568 569 // _GLIBCXX_RESOLVE_LIB_DEFECTS 570 // 214. set::find() missing const overload 571 //@{ 572 /** 573 * @brief Tries to locate an element in a %set. 574 * @param x Element to be located. 575 * @return Iterator pointing to sought-after element, or end() if not 576 * found. 577 * 578 * This function takes a key and tries to locate the element with which 579 * the key matches. If successful the function returns an iterator 580 * pointing to the sought after element. If unsuccessful it returns the 581 * past-the-end ( @c end() ) iterator. 582 */ 583 iterator 584 find(const key_type& __x) 585 { return _M_t.find(__x); } 586 587 const_iterator 588 find(const key_type& __x) const 589 { return _M_t.find(__x); } 590 //@} 591 592 //@{ 593 /** 594 * @brief Finds the beginning of a subsequence matching given key. 595 * @param x Key to be located. 596 * @return Iterator pointing to first element equal to or greater 597 * than key, or end(). 598 * 599 * This function returns the first element of a subsequence of elements 600 * that matches the given key. If unsuccessful it returns an iterator 601 * pointing to the first element that has a greater value than given key 602 * or end() if no such element exists. 603 */ 604 iterator 605 lower_bound(const key_type& __x) 606 { return _M_t.lower_bound(__x); } 607 608 const_iterator 609 lower_bound(const key_type& __x) const 610 { return _M_t.lower_bound(__x); } 611 //@} 612 613 //@{ 614 /** 615 * @brief Finds the end of a subsequence matching given key. 616 * @param x Key to be located. 617 * @return Iterator pointing to the first element 618 * greater than key, or end(). 619 */ 620 iterator 621 upper_bound(const key_type& __x) 622 { return _M_t.upper_bound(__x); } 623 624 const_iterator 625 upper_bound(const key_type& __x) const 626 { return _M_t.upper_bound(__x); } 627 //@} 628 629 //@{ 630 /** 631 * @brief Finds a subsequence matching given key. 632 * @param x Key to be located. 633 * @return Pair of iterators that possibly points to the subsequence 634 * matching given key. 635 * 636 * This function is equivalent to 637 * @code 638 * std::make_pair(c.lower_bound(val), 639 * c.upper_bound(val)) 640 * @endcode 641 * (but is faster than making the calls separately). 642 * 643 * This function probably only makes sense for multisets. 644 */ 645 std::pair<iterator, iterator> 646 equal_range(const key_type& __x) 647 { return _M_t.equal_range(__x); } 648 649 std::pair<const_iterator, const_iterator> 650 equal_range(const key_type& __x) const 651 { return _M_t.equal_range(__x); } 652 //@} 653 654 template<typename _K1, typename _C1, typename _A1> 655 friend bool 656 operator==(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&); 657 658 template<typename _K1, typename _C1, typename _A1> 659 friend bool 660 operator<(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&); 661 }; 662 663 664 /** 665 * @brief Set equality comparison. 666 * @param x A %set. 667 * @param y A %set of the same type as @a x. 668 * @return True iff the size and elements of the sets are equal. 669 * 670 * This is an equivalence relation. It is linear in the size of the sets. 671 * Sets are considered equivalent if their sizes are equal, and if 672 * corresponding elements compare equal. 673 */ 674 template<typename _Key, typename _Compare, typename _Alloc> 675 inline bool 676 operator==(const set<_Key, _Compare, _Alloc>& __x, 677 const set<_Key, _Compare, _Alloc>& __y) 678 { return __x._M_t == __y._M_t; } 679 680 /** 681 * @brief Set ordering relation. 682 * @param x A %set. 683 * @param y A %set of the same type as @a x. 684 * @return True iff @a x is lexicographically less than @a y. 685 * 686 * This is a total ordering relation. It is linear in the size of the 687 * maps. The elements must be comparable with @c <. 688 * 689 * See std::lexicographical_compare() for how the determination is made. 690 */ 691 template<typename _Key, typename _Compare, typename _Alloc> 692 inline bool 693 operator<(const set<_Key, _Compare, _Alloc>& __x, 694 const set<_Key, _Compare, _Alloc>& __y) 695 { return __x._M_t < __y._M_t; } 696 697 /// Returns !(x == y). 698 template<typename _Key, typename _Compare, typename _Alloc> 699 inline bool 700 operator!=(const set<_Key, _Compare, _Alloc>& __x, 701 const set<_Key, _Compare, _Alloc>& __y) 702 { return !(__x == __y); } 703 704 /// Returns y < x. 705 template<typename _Key, typename _Compare, typename _Alloc> 706 inline bool 707 operator>(const set<_Key, _Compare, _Alloc>& __x, 708 const set<_Key, _Compare, _Alloc>& __y) 709 { return __y < __x; } 710 711 /// Returns !(y < x) 712 template<typename _Key, typename _Compare, typename _Alloc> 713 inline bool 714 operator<=(const set<_Key, _Compare, _Alloc>& __x, 715 const set<_Key, _Compare, _Alloc>& __y) 716 { return !(__y < __x); } 717 718 /// Returns !(x < y) 719 template<typename _Key, typename _Compare, typename _Alloc> 720 inline bool 721 operator>=(const set<_Key, _Compare, _Alloc>& __x, 722 const set<_Key, _Compare, _Alloc>& __y) 723 { return !(__x < __y); } 724 725 /// See std::set::swap(). 726 template<typename _Key, typename _Compare, typename _Alloc> 727 inline void 728 swap(set<_Key, _Compare, _Alloc>& __x, set<_Key, _Compare, _Alloc>& __y) 729 { __x.swap(__y); } 730 731_GLIBCXX_END_NESTED_NAMESPACE 732 733#endif /* _STL_SET_H */ 734