1 // Set implementation -*- C++ -*- 2 3 // Copyright (C) 2001-2014 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 3, 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 // Under Section 7 of GPL version 3, you are granted additional 17 // permissions described in the GCC Runtime Library Exception, version 18 // 3.1, as published by the Free Software Foundation. 19 20 // You should have received a copy of the GNU General Public License and 21 // a copy of the GCC Runtime Library Exception along with this program; 22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23 // <http://www.gnu.org/licenses/>. 24 25 /* 26 * 27 * Copyright (c) 1994 28 * Hewlett-Packard Company 29 * 30 * Permission to use, copy, modify, distribute and sell this software 31 * and its documentation for any purpose is hereby granted without fee, 32 * provided that the above copyright notice appear in all copies and 33 * that both that copyright notice and this permission notice appear 34 * in supporting documentation. Hewlett-Packard Company makes no 35 * representations about the suitability of this software for any 36 * purpose. It is provided "as is" without express or implied warranty. 37 * 38 * 39 * Copyright (c) 1996,1997 40 * Silicon Graphics Computer Systems, Inc. 41 * 42 * Permission to use, copy, modify, distribute and sell this software 43 * and its documentation for any purpose is hereby granted without fee, 44 * provided that the above copyright notice appear in all copies and 45 * that both that copyright notice and this permission notice appear 46 * in supporting documentation. Silicon Graphics makes no 47 * representations about the suitability of this software for any 48 * purpose. It is provided "as is" without express or implied warranty. 49 */ 50 51 /** @file bits/stl_set.h 52 * This is an internal header file, included by other library headers. 53 * Do not attempt to use it directly. @headername{set} 54 */ 55 56 #ifndef _STL_SET_H 57 #define _STL_SET_H 1 58 59 #include <bits/concept_check.h> 60 #if __cplusplus >= 201103L 61 #include <initializer_list> 62 #endif 63 64 namespace std _GLIBCXX_VISIBILITY(default) 65 { 66 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER 67 68 /** 69 * @brief A standard container made up of unique keys, which can be 70 * retrieved in logarithmic time. 71 * 72 * @ingroup associative_containers 73 * 74 * @tparam _Key Type of key objects. 75 * @tparam _Compare Comparison function object type, defaults to less<_Key>. 76 * @tparam _Alloc Allocator type, defaults to allocator<_Key>. 77 * 78 * Meets the requirements of a <a href="tables.html#65">container</a>, a 79 * <a href="tables.html#66">reversible container</a>, and an 80 * <a href="tables.html#69">associative container</a> (using unique keys). 81 * 82 * Sets support bidirectional iterators. 83 * 84 * The private tree data is declared exactly the same way for set and 85 * multiset; the distinction is made entirely in how the tree functions are 86 * called (*_unique versus *_equal, same as the standard). 87 */ 88 template<typename _Key, typename _Compare = std::less<_Key>, 89 typename _Alloc = std::allocator<_Key> > 90 class set 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 //@{ 102 /// Public typedefs. 103 typedef _Key key_type; 104 typedef _Key value_type; 105 typedef _Compare key_compare; 106 typedef _Compare value_compare; 107 typedef _Alloc allocator_type; 108 //@} 109 110 private: 111 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template 112 rebind<_Key>::other _Key_alloc_type; 113 114 typedef _Rb_tree<key_type, value_type, _Identity<value_type>, 115 key_compare, _Key_alloc_type> _Rep_type; 116 _Rep_type _M_t; // Red-black tree representing set. 117 118 typedef __gnu_cxx::__alloc_traits<_Key_alloc_type> _Alloc_traits; 119 120 public: 121 //@{ 122 /// Iterator-related typedefs. 123 typedef typename _Alloc_traits::pointer pointer; 124 typedef typename _Alloc_traits::const_pointer const_pointer; 125 typedef typename _Alloc_traits::reference reference; 126 typedef typename _Alloc_traits::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 /** 140 * @brief Default constructor creates no elements. 141 */ 142 set() 143 : _M_t() { } 144 145 /** 146 * @brief Creates a %set with no elements. 147 * @param __comp Comparator to use. 148 * @param __a An allocator object. 149 */ 150 explicit 151 set(const _Compare& __comp, 152 const allocator_type& __a = allocator_type()) 153 : _M_t(__comp, _Key_alloc_type(__a)) { } 154 155 /** 156 * @brief Builds a %set from a range. 157 * @param __first An input iterator. 158 * @param __last An input iterator. 159 * 160 * Create a %set consisting of copies of the elements from 161 * [__first,__last). This is linear in N if the range is 162 * already sorted, and NlogN otherwise (where N is 163 * distance(__first,__last)). 164 */ 165 template<typename _InputIterator> 166 set(_InputIterator __first, _InputIterator __last) 167 : _M_t() 168 { _M_t._M_insert_unique(__first, __last); } 169 170 /** 171 * @brief Builds a %set from a range. 172 * @param __first An input iterator. 173 * @param __last An input iterator. 174 * @param __comp A comparison functor. 175 * @param __a An allocator object. 176 * 177 * Create a %set consisting of copies of the elements from 178 * [__first,__last). This is linear in N if the range is 179 * already sorted, and NlogN otherwise (where N is 180 * distance(__first,__last)). 181 */ 182 template<typename _InputIterator> 183 set(_InputIterator __first, _InputIterator __last, 184 const _Compare& __comp, 185 const allocator_type& __a = allocator_type()) 186 : _M_t(__comp, _Key_alloc_type(__a)) 187 { _M_t._M_insert_unique(__first, __last); } 188 189 /** 190 * @brief %Set copy constructor. 191 * @param __x A %set of identical element and allocator types. 192 * 193 * The newly-created %set uses a copy of the allocation object used 194 * by @a __x. 195 */ 196 set(const set& __x) 197 : _M_t(__x._M_t) { } 198 199 #if __cplusplus >= 201103L 200 /** 201 * @brief %Set move constructor 202 * @param __x A %set of identical element and allocator types. 203 * 204 * The newly-created %set contains the exact contents of @a x. 205 * The contents of @a x are a valid, but unspecified %set. 206 */ 207 set(set&& __x) 208 noexcept(is_nothrow_copy_constructible<_Compare>::value) 209 : _M_t(std::move(__x._M_t)) { } 210 211 /** 212 * @brief Builds a %set from an initializer_list. 213 * @param __l An initializer_list. 214 * @param __comp A comparison functor. 215 * @param __a An allocator object. 216 * 217 * Create a %set consisting of copies of the elements in the list. 218 * This is linear in N if the list is already sorted, and NlogN 219 * otherwise (where N is @a __l.size()). 220 */ 221 set(initializer_list<value_type> __l, 222 const _Compare& __comp = _Compare(), 223 const allocator_type& __a = allocator_type()) 224 : _M_t(__comp, _Key_alloc_type(__a)) 225 { _M_t._M_insert_unique(__l.begin(), __l.end()); } 226 227 /// Allocator-extended default constructor. 228 explicit 229 set(const allocator_type& __a) 230 : _M_t(_Compare(), _Key_alloc_type(__a)) { } 231 232 /// Allocator-extended copy constructor. 233 set(const set& __x, const allocator_type& __a) 234 : _M_t(__x._M_t, _Key_alloc_type(__a)) { } 235 236 /// Allocator-extended move constructor. 237 set(set&& __x, const allocator_type& __a) 238 noexcept(is_nothrow_copy_constructible<_Compare>::value 239 && _Alloc_traits::_S_always_equal()) 240 : _M_t(std::move(__x._M_t), _Key_alloc_type(__a)) { } 241 242 /// Allocator-extended initialier-list constructor. 243 set(initializer_list<value_type> __l, const allocator_type& __a) 244 : _M_t(_Compare(), _Key_alloc_type(__a)) 245 { _M_t._M_insert_unique(__l.begin(), __l.end()); } 246 247 /// Allocator-extended range constructor. 248 template<typename _InputIterator> 249 set(_InputIterator __first, _InputIterator __last, 250 const allocator_type& __a) 251 : _M_t(_Compare(), _Key_alloc_type(__a)) 252 { _M_t._M_insert_unique(__first, __last); } 253 #endif 254 255 /** 256 * @brief %Set assignment operator. 257 * @param __x A %set of identical element and allocator types. 258 * 259 * All the elements of @a __x are copied, but unlike the copy 260 * constructor, the allocator object is not copied. 261 */ 262 set& 263 operator=(const set& __x) 264 { 265 _M_t = __x._M_t; 266 return *this; 267 } 268 269 #if __cplusplus >= 201103L 270 /** 271 * @brief %Set move assignment operator. 272 * @param __x A %set of identical element and allocator types. 273 * 274 * The contents of @a __x are moved into this %set (without copying 275 * if the allocators compare equal or get moved on assignment). 276 * Afterwards @a __x is in a valid, but unspecified state. 277 */ 278 set& 279 operator=(set&& __x) noexcept(_Alloc_traits::_S_nothrow_move()) 280 { 281 if (!_M_t._M_move_assign(__x._M_t)) 282 { 283 // The rvalue's allocator cannot be moved and is not equal, 284 // so we need to individually move each element. 285 clear(); 286 insert(std::__make_move_if_noexcept_iterator(__x._M_t.begin()), 287 std::__make_move_if_noexcept_iterator(__x._M_t.end())); 288 __x.clear(); 289 } 290 return *this; 291 } 292 293 /** 294 * @brief %Set list assignment operator. 295 * @param __l An initializer_list. 296 * 297 * This function fills a %set with copies of the elements in the 298 * initializer list @a __l. 299 * 300 * Note that the assignment completely changes the %set and 301 * that the resulting %set's size is the same as the number 302 * of elements assigned. Old data may be lost. 303 */ 304 set& 305 operator=(initializer_list<value_type> __l) 306 { 307 this->clear(); 308 this->insert(__l.begin(), __l.end()); 309 return *this; 310 } 311 #endif 312 313 // accessors: 314 315 /// Returns the comparison object with which the %set was constructed. 316 key_compare 317 key_comp() const 318 { return _M_t.key_comp(); } 319 /// Returns the comparison object with which the %set was constructed. 320 value_compare 321 value_comp() const 322 { return _M_t.key_comp(); } 323 /// Returns the allocator object with which the %set was constructed. 324 allocator_type 325 get_allocator() const _GLIBCXX_NOEXCEPT 326 { return allocator_type(_M_t.get_allocator()); } 327 328 /** 329 * Returns a read-only (constant) iterator that points to the first 330 * element in the %set. Iteration is done in ascending order according 331 * to the keys. 332 */ 333 iterator 334 begin() const _GLIBCXX_NOEXCEPT 335 { return _M_t.begin(); } 336 337 /** 338 * Returns a read-only (constant) iterator that points one past the last 339 * element in the %set. Iteration is done in ascending order according 340 * to the keys. 341 */ 342 iterator 343 end() const _GLIBCXX_NOEXCEPT 344 { return _M_t.end(); } 345 346 /** 347 * Returns a read-only (constant) iterator that points to the last 348 * element in the %set. Iteration is done in descending order according 349 * to the keys. 350 */ 351 reverse_iterator 352 rbegin() const _GLIBCXX_NOEXCEPT 353 { return _M_t.rbegin(); } 354 355 /** 356 * Returns a read-only (constant) reverse iterator that points to the 357 * last pair in the %set. Iteration is done in descending order 358 * according to the keys. 359 */ 360 reverse_iterator 361 rend() const _GLIBCXX_NOEXCEPT 362 { return _M_t.rend(); } 363 364 #if __cplusplus >= 201103L 365 /** 366 * Returns a read-only (constant) iterator that points to the first 367 * element in the %set. Iteration is done in ascending order according 368 * to the keys. 369 */ 370 iterator 371 cbegin() const noexcept 372 { return _M_t.begin(); } 373 374 /** 375 * Returns a read-only (constant) iterator that points one past the last 376 * element in the %set. Iteration is done in ascending order according 377 * to the keys. 378 */ 379 iterator 380 cend() const noexcept 381 { return _M_t.end(); } 382 383 /** 384 * Returns a read-only (constant) iterator that points to the last 385 * element in the %set. Iteration is done in descending order according 386 * to the keys. 387 */ 388 reverse_iterator 389 crbegin() const noexcept 390 { return _M_t.rbegin(); } 391 392 /** 393 * Returns a read-only (constant) reverse iterator that points to the 394 * last pair in the %set. Iteration is done in descending order 395 * according to the keys. 396 */ 397 reverse_iterator 398 crend() const noexcept 399 { return _M_t.rend(); } 400 #endif 401 402 /// Returns true if the %set is empty. 403 bool 404 empty() const _GLIBCXX_NOEXCEPT 405 { return _M_t.empty(); } 406 407 /// Returns the size of the %set. 408 size_type 409 size() const _GLIBCXX_NOEXCEPT 410 { return _M_t.size(); } 411 412 /// Returns the maximum size of the %set. 413 size_type 414 max_size() const _GLIBCXX_NOEXCEPT 415 { return _M_t.max_size(); } 416 417 /** 418 * @brief Swaps data with another %set. 419 * @param __x A %set of the same element and allocator types. 420 * 421 * This exchanges the elements between two sets in constant 422 * time. (It is only swapping a pointer, an integer, and an 423 * instance of the @c Compare type (which itself is often 424 * stateless and empty), so it should be quite fast.) Note 425 * that the global std::swap() function is specialized such 426 * that std::swap(s1,s2) will feed to this function. 427 */ 428 void 429 swap(set& __x) 430 #if __cplusplus >= 201103L 431 noexcept(_Alloc_traits::_S_nothrow_swap()) 432 #endif 433 { _M_t.swap(__x._M_t); } 434 435 // insert/erase 436 #if __cplusplus >= 201103L 437 /** 438 * @brief Attempts to build and insert an element into the %set. 439 * @param __args Arguments used to generate an element. 440 * @return A pair, of which the first element is an iterator that points 441 * to the possibly inserted element, and the second is a bool 442 * that is true if the element was actually inserted. 443 * 444 * This function attempts to build and insert an element into the %set. 445 * A %set relies on unique keys and thus an element is only inserted if 446 * it is not already present in the %set. 447 * 448 * Insertion requires logarithmic time. 449 */ 450 template<typename... _Args> 451 std::pair<iterator, bool> 452 emplace(_Args&&... __args) 453 { return _M_t._M_emplace_unique(std::forward<_Args>(__args)...); } 454 455 /** 456 * @brief Attempts to insert an element into the %set. 457 * @param __pos An iterator that serves as a hint as to where the 458 * element should be inserted. 459 * @param __args Arguments used to generate the element to be 460 * inserted. 461 * @return An iterator that points to the element with key equivalent to 462 * the one generated from @a __args (may or may not be the 463 * element itself). 464 * 465 * This function is not concerned about whether the insertion took place, 466 * and thus does not return a boolean like the single-argument emplace() 467 * does. Note that the first parameter is only a hint and can 468 * potentially improve the performance of the insertion process. A bad 469 * hint would cause no gains in efficiency. 470 * 471 * For more on @a hinting, see: 472 * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html 473 * 474 * Insertion requires logarithmic time (if the hint is not taken). 475 */ 476 template<typename... _Args> 477 iterator 478 emplace_hint(const_iterator __pos, _Args&&... __args) 479 { 480 return _M_t._M_emplace_hint_unique(__pos, 481 std::forward<_Args>(__args)...); 482 } 483 #endif 484 485 /** 486 * @brief Attempts to insert an element into the %set. 487 * @param __x Element to be inserted. 488 * @return A pair, of which the first element is an iterator that points 489 * to the possibly inserted element, and the second is a bool 490 * that is true if the element was actually inserted. 491 * 492 * This function attempts to insert an element into the %set. A %set 493 * relies on unique keys and thus an element is only inserted if it is 494 * not already present in the %set. 495 * 496 * Insertion requires logarithmic time. 497 */ 498 std::pair<iterator, bool> 499 insert(const value_type& __x) 500 { 501 std::pair<typename _Rep_type::iterator, bool> __p = 502 _M_t._M_insert_unique(__x); 503 return std::pair<iterator, bool>(__p.first, __p.second); 504 } 505 506 #if __cplusplus >= 201103L 507 std::pair<iterator, bool> 508 insert(value_type&& __x) 509 { 510 std::pair<typename _Rep_type::iterator, bool> __p = 511 _M_t._M_insert_unique(std::move(__x)); 512 return std::pair<iterator, bool>(__p.first, __p.second); 513 } 514 #endif 515 516 /** 517 * @brief Attempts to insert an element into the %set. 518 * @param __position An iterator that serves as a hint as to where the 519 * element should be inserted. 520 * @param __x Element to be inserted. 521 * @return An iterator that points to the element with key of 522 * @a __x (may or may not be the element passed in). 523 * 524 * This function is not concerned about whether the insertion took place, 525 * and thus does not return a boolean like the single-argument insert() 526 * does. Note that the first parameter is only a hint and can 527 * potentially improve the performance of the insertion process. A bad 528 * hint would cause no gains in efficiency. 529 * 530 * For more on @a hinting, see: 531 * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html 532 * 533 * Insertion requires logarithmic time (if the hint is not taken). 534 */ 535 iterator 536 insert(const_iterator __position, const value_type& __x) 537 { return _M_t._M_insert_unique_(__position, __x); } 538 539 #if __cplusplus >= 201103L 540 iterator 541 insert(const_iterator __position, value_type&& __x) 542 { return _M_t._M_insert_unique_(__position, std::move(__x)); } 543 #endif 544 545 /** 546 * @brief A template function that attempts to insert a range 547 * of elements. 548 * @param __first Iterator pointing to the start of the range to be 549 * inserted. 550 * @param __last Iterator pointing to the end of the range. 551 * 552 * Complexity similar to that of the range constructor. 553 */ 554 template<typename _InputIterator> 555 void 556 insert(_InputIterator __first, _InputIterator __last) 557 { _M_t._M_insert_unique(__first, __last); } 558 559 #if __cplusplus >= 201103L 560 /** 561 * @brief Attempts to insert a list of elements into the %set. 562 * @param __l A std::initializer_list<value_type> of elements 563 * to be inserted. 564 * 565 * Complexity similar to that of the range constructor. 566 */ 567 void 568 insert(initializer_list<value_type> __l) 569 { this->insert(__l.begin(), __l.end()); } 570 #endif 571 572 #if __cplusplus >= 201103L 573 // _GLIBCXX_RESOLVE_LIB_DEFECTS 574 // DR 130. Associative erase should return an iterator. 575 /** 576 * @brief Erases an element from a %set. 577 * @param __position An iterator pointing to the element to be erased. 578 * @return An iterator pointing to the element immediately following 579 * @a __position prior to the element being erased. If no such 580 * element exists, end() is returned. 581 * 582 * This function erases an element, pointed to by the given iterator, 583 * from a %set. Note that this function only erases the element, and 584 * that if the element is itself a pointer, the pointed-to memory is not 585 * touched in any way. Managing the pointer is the user's 586 * responsibility. 587 */ 588 _GLIBCXX_ABI_TAG_CXX11 589 iterator 590 erase(const_iterator __position) 591 { return _M_t.erase(__position); } 592 #else 593 /** 594 * @brief Erases an element from a %set. 595 * @param position An iterator pointing to the element to be erased. 596 * 597 * This function erases an element, pointed to by the given iterator, 598 * from a %set. Note that this function only erases the element, and 599 * that if the element is itself a pointer, the pointed-to memory is not 600 * touched in any way. Managing the pointer is the user's 601 * responsibility. 602 */ 603 void 604 erase(iterator __position) 605 { _M_t.erase(__position); } 606 #endif 607 608 /** 609 * @brief Erases elements according to the provided key. 610 * @param __x Key of element to be erased. 611 * @return The number of elements erased. 612 * 613 * This function erases all the elements located by the given key from 614 * a %set. 615 * Note that this function only erases the element, and that if 616 * the element is itself a pointer, the pointed-to memory is not touched 617 * in any way. Managing the pointer is the user's responsibility. 618 */ 619 size_type 620 erase(const key_type& __x) 621 { return _M_t.erase(__x); } 622 623 #if __cplusplus >= 201103L 624 // _GLIBCXX_RESOLVE_LIB_DEFECTS 625 // DR 130. Associative erase should return an iterator. 626 /** 627 * @brief Erases a [__first,__last) range of elements from a %set. 628 * @param __first Iterator pointing to the start of the range to be 629 * erased. 630 631 * @param __last Iterator pointing to the end of the range to 632 * be erased. 633 * @return The iterator @a __last. 634 * 635 * This function erases a sequence of elements from a %set. 636 * Note that this function only erases the element, and that if 637 * the element is itself a pointer, the pointed-to memory is not touched 638 * in any way. Managing the pointer is the user's responsibility. 639 */ 640 _GLIBCXX_ABI_TAG_CXX11 641 iterator 642 erase(const_iterator __first, const_iterator __last) 643 { return _M_t.erase(__first, __last); } 644 #else 645 /** 646 * @brief Erases a [first,last) range of elements from a %set. 647 * @param __first Iterator pointing to the start of the range to be 648 * erased. 649 * @param __last Iterator pointing to the end of the range to 650 * be erased. 651 * 652 * This function erases a sequence of elements from a %set. 653 * Note that this function only erases the element, and that if 654 * the element is itself a pointer, the pointed-to memory is not touched 655 * in any way. Managing the pointer is the user's responsibility. 656 */ 657 void 658 erase(iterator __first, iterator __last) 659 { _M_t.erase(__first, __last); } 660 #endif 661 662 /** 663 * Erases all elements in a %set. Note that this function only erases 664 * the elements, and that if the elements themselves are pointers, the 665 * pointed-to memory is not touched in any way. Managing the pointer is 666 * the user's responsibility. 667 */ 668 void 669 clear() _GLIBCXX_NOEXCEPT 670 { _M_t.clear(); } 671 672 // set operations: 673 674 /** 675 * @brief Finds the number of elements. 676 * @param __x Element to located. 677 * @return Number of elements with specified key. 678 * 679 * This function only makes sense for multisets; for set the result will 680 * either be 0 (not present) or 1 (present). 681 */ 682 size_type 683 count(const key_type& __x) const 684 { return _M_t.find(__x) == _M_t.end() ? 0 : 1; } 685 686 // _GLIBCXX_RESOLVE_LIB_DEFECTS 687 // 214. set::find() missing const overload 688 //@{ 689 /** 690 * @brief Tries to locate an element in a %set. 691 * @param __x Element to be located. 692 * @return Iterator pointing to sought-after element, or end() if not 693 * found. 694 * 695 * This function takes a key and tries to locate the element with which 696 * the key matches. If successful the function returns an iterator 697 * pointing to the sought after element. If unsuccessful it returns the 698 * past-the-end ( @c end() ) iterator. 699 */ 700 iterator 701 find(const key_type& __x) 702 { return _M_t.find(__x); } 703 704 const_iterator 705 find(const key_type& __x) const 706 { return _M_t.find(__x); } 707 //@} 708 709 //@{ 710 /** 711 * @brief Finds the beginning of a subsequence matching given key. 712 * @param __x Key to be located. 713 * @return Iterator pointing to first element equal to or greater 714 * than key, or end(). 715 * 716 * This function returns the first element of a subsequence of elements 717 * that matches the given key. If unsuccessful it returns an iterator 718 * pointing to the first element that has a greater value than given key 719 * or end() if no such element exists. 720 */ 721 iterator 722 lower_bound(const key_type& __x) 723 { return _M_t.lower_bound(__x); } 724 725 const_iterator 726 lower_bound(const key_type& __x) const 727 { return _M_t.lower_bound(__x); } 728 //@} 729 730 //@{ 731 /** 732 * @brief Finds the end of a subsequence matching given key. 733 * @param __x Key to be located. 734 * @return Iterator pointing to the first element 735 * greater than key, or end(). 736 */ 737 iterator 738 upper_bound(const key_type& __x) 739 { return _M_t.upper_bound(__x); } 740 741 const_iterator 742 upper_bound(const key_type& __x) const 743 { return _M_t.upper_bound(__x); } 744 //@} 745 746 //@{ 747 /** 748 * @brief Finds a subsequence matching given key. 749 * @param __x Key to be located. 750 * @return Pair of iterators that possibly points to the subsequence 751 * matching given key. 752 * 753 * This function is equivalent to 754 * @code 755 * std::make_pair(c.lower_bound(val), 756 * c.upper_bound(val)) 757 * @endcode 758 * (but is faster than making the calls separately). 759 * 760 * This function probably only makes sense for multisets. 761 */ 762 std::pair<iterator, iterator> 763 equal_range(const key_type& __x) 764 { return _M_t.equal_range(__x); } 765 766 std::pair<const_iterator, const_iterator> 767 equal_range(const key_type& __x) const 768 { return _M_t.equal_range(__x); } 769 //@} 770 771 template<typename _K1, typename _C1, typename _A1> 772 friend bool 773 operator==(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&); 774 775 template<typename _K1, typename _C1, typename _A1> 776 friend bool 777 operator<(const set<_K1, _C1, _A1>&, const set<_K1, _C1, _A1>&); 778 }; 779 780 781 /** 782 * @brief Set equality comparison. 783 * @param __x A %set. 784 * @param __y A %set of the same type as @a x. 785 * @return True iff the size and elements of the sets are equal. 786 * 787 * This is an equivalence relation. It is linear in the size of the sets. 788 * Sets are considered equivalent if their sizes are equal, and if 789 * corresponding elements compare equal. 790 */ 791 template<typename _Key, typename _Compare, typename _Alloc> 792 inline bool 793 operator==(const set<_Key, _Compare, _Alloc>& __x, 794 const set<_Key, _Compare, _Alloc>& __y) 795 { return __x._M_t == __y._M_t; } 796 797 /** 798 * @brief Set ordering relation. 799 * @param __x A %set. 800 * @param __y A %set of the same type as @a x. 801 * @return True iff @a __x is lexicographically less than @a __y. 802 * 803 * This is a total ordering relation. It is linear in the size of the 804 * sets. The elements must be comparable with @c <. 805 * 806 * See std::lexicographical_compare() for how the determination is made. 807 */ 808 template<typename _Key, typename _Compare, typename _Alloc> 809 inline bool 810 operator<(const set<_Key, _Compare, _Alloc>& __x, 811 const set<_Key, _Compare, _Alloc>& __y) 812 { return __x._M_t < __y._M_t; } 813 814 /// Returns !(x == y). 815 template<typename _Key, typename _Compare, typename _Alloc> 816 inline bool 817 operator!=(const set<_Key, _Compare, _Alloc>& __x, 818 const set<_Key, _Compare, _Alloc>& __y) 819 { return !(__x == __y); } 820 821 /// Returns y < x. 822 template<typename _Key, typename _Compare, typename _Alloc> 823 inline bool 824 operator>(const set<_Key, _Compare, _Alloc>& __x, 825 const set<_Key, _Compare, _Alloc>& __y) 826 { return __y < __x; } 827 828 /// Returns !(y < x) 829 template<typename _Key, typename _Compare, typename _Alloc> 830 inline bool 831 operator<=(const set<_Key, _Compare, _Alloc>& __x, 832 const set<_Key, _Compare, _Alloc>& __y) 833 { return !(__y < __x); } 834 835 /// Returns !(x < y) 836 template<typename _Key, typename _Compare, typename _Alloc> 837 inline bool 838 operator>=(const set<_Key, _Compare, _Alloc>& __x, 839 const set<_Key, _Compare, _Alloc>& __y) 840 { return !(__x < __y); } 841 842 /// See std::set::swap(). 843 template<typename _Key, typename _Compare, typename _Alloc> 844 inline void 845 swap(set<_Key, _Compare, _Alloc>& __x, set<_Key, _Compare, _Alloc>& __y) 846 { __x.swap(__y); } 847 848 _GLIBCXX_END_NAMESPACE_CONTAINER 849 } //namespace std 850 #endif /* _STL_SET_H */ 851