1 // Map 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_map.h 52 * This is an internal header file, included by other library headers. 53 * Do not attempt to use it directly. @headername{map} 54 */ 55 56 #ifndef _STL_MAP_H 57 #define _STL_MAP_H 1 58 59 #include <bits/functexcept.h> 60 #include <bits/concept_check.h> 61 #if __cplusplus >= 201103L 62 #include <initializer_list> 63 #include <tuple> 64 #endif 65 66 namespace std _GLIBCXX_VISIBILITY(default) 67 { 68 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER 69 70 /** 71 * @brief A standard container made up of (key,value) pairs, which can be 72 * retrieved based on a key, in logarithmic time. 73 * 74 * @ingroup associative_containers 75 * 76 * @tparam _Key Type of key objects. 77 * @tparam _Tp Type of mapped objects. 78 * @tparam _Compare Comparison function object type, defaults to less<_Key>. 79 * @tparam _Alloc Allocator type, defaults to 80 * allocator<pair<const _Key, _Tp>. 81 * 82 * Meets the requirements of a <a href="tables.html#65">container</a>, a 83 * <a href="tables.html#66">reversible container</a>, and an 84 * <a href="tables.html#69">associative container</a> (using unique keys). 85 * For a @c map<Key,T> the key_type is Key, the mapped_type is T, and the 86 * value_type is std::pair<const Key,T>. 87 * 88 * Maps support bidirectional iterators. 89 * 90 * The private tree data is declared exactly the same way for map and 91 * multimap; the distinction is made entirely in how the tree functions are 92 * called (*_unique versus *_equal, same as the standard). 93 */ 94 template <typename _Key, typename _Tp, typename _Compare = std::less<_Key>, 95 typename _Alloc = std::allocator<std::pair<const _Key, _Tp> > > 96 class map 97 { 98 public: 99 typedef _Key key_type; 100 typedef _Tp mapped_type; 101 typedef std::pair<const _Key, _Tp> value_type; 102 typedef _Compare key_compare; 103 typedef _Alloc allocator_type; 104 105 private: 106 // concept requirements 107 typedef typename _Alloc::value_type _Alloc_value_type; 108 __glibcxx_class_requires(_Tp, _SGIAssignableConcept) 109 __glibcxx_class_requires4(_Compare, bool, _Key, _Key, 110 _BinaryFunctionConcept) 111 __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept) 112 113 public: 114 class value_compare 115 : public std::binary_function<value_type, value_type, bool> 116 { 117 friend class map<_Key, _Tp, _Compare, _Alloc>; 118 protected: 119 _Compare comp; 120 121 value_compare(_Compare __c) 122 : comp(__c) { } 123 124 public: 125 bool operator()(const value_type& __x, const value_type& __y) const 126 { return comp(__x.first, __y.first); } 127 }; 128 129 private: 130 /// This turns a red-black tree into a [multi]map. 131 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template 132 rebind<value_type>::other _Pair_alloc_type; 133 134 typedef _Rb_tree<key_type, value_type, _Select1st<value_type>, 135 key_compare, _Pair_alloc_type> _Rep_type; 136 137 /// The actual tree structure. 138 _Rep_type _M_t; 139 140 typedef __gnu_cxx::__alloc_traits<_Pair_alloc_type> _Alloc_traits; 141 142 public: 143 // many of these are specified differently in ISO, but the following are 144 // "functionally equivalent" 145 typedef typename _Alloc_traits::pointer pointer; 146 typedef typename _Alloc_traits::const_pointer const_pointer; 147 typedef typename _Alloc_traits::reference reference; 148 typedef typename _Alloc_traits::const_reference const_reference; 149 typedef typename _Rep_type::iterator iterator; 150 typedef typename _Rep_type::const_iterator const_iterator; 151 typedef typename _Rep_type::size_type size_type; 152 typedef typename _Rep_type::difference_type difference_type; 153 typedef typename _Rep_type::reverse_iterator reverse_iterator; 154 typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator; 155 156 // [23.3.1.1] construct/copy/destroy 157 // (get_allocator() is also listed in this section) 158 159 /** 160 * @brief Default constructor creates no elements. 161 */ 162 map() 163 : _M_t() { } 164 165 /** 166 * @brief Creates a %map with no elements. 167 * @param __comp A comparison object. 168 * @param __a An allocator object. 169 */ 170 explicit 171 map(const _Compare& __comp, 172 const allocator_type& __a = allocator_type()) 173 : _M_t(__comp, _Pair_alloc_type(__a)) { } 174 175 /** 176 * @brief %Map copy constructor. 177 * @param __x A %map of identical element and allocator types. 178 * 179 * The newly-created %map uses a copy of the allocation object 180 * used by @a __x. 181 */ 182 map(const map& __x) 183 : _M_t(__x._M_t) { } 184 185 #if __cplusplus >= 201103L 186 /** 187 * @brief %Map move constructor. 188 * @param __x A %map of identical element and allocator types. 189 * 190 * The newly-created %map contains the exact contents of @a __x. 191 * The contents of @a __x are a valid, but unspecified %map. 192 */ 193 map(map&& __x) 194 noexcept(is_nothrow_copy_constructible<_Compare>::value) 195 : _M_t(std::move(__x._M_t)) { } 196 197 /** 198 * @brief Builds a %map from an initializer_list. 199 * @param __l An initializer_list. 200 * @param __comp A comparison object. 201 * @param __a An allocator object. 202 * 203 * Create a %map consisting of copies of the elements in the 204 * initializer_list @a __l. 205 * This is linear in N if the range is already sorted, and NlogN 206 * otherwise (where N is @a __l.size()). 207 */ 208 map(initializer_list<value_type> __l, 209 const _Compare& __comp = _Compare(), 210 const allocator_type& __a = allocator_type()) 211 : _M_t(__comp, _Pair_alloc_type(__a)) 212 { _M_t._M_insert_unique(__l.begin(), __l.end()); } 213 214 /// Allocator-extended default constructor. 215 explicit 216 map(const allocator_type& __a) 217 : _M_t(_Compare(), _Pair_alloc_type(__a)) { } 218 219 /// Allocator-extended copy constructor. 220 map(const map& __m, const allocator_type& __a) 221 : _M_t(__m._M_t, _Pair_alloc_type(__a)) { } 222 223 /// Allocator-extended move constructor. 224 map(map&& __m, const allocator_type& __a) 225 noexcept(is_nothrow_copy_constructible<_Compare>::value 226 && _Alloc_traits::_S_always_equal()) 227 : _M_t(std::move(__m._M_t), _Pair_alloc_type(__a)) { } 228 229 /// Allocator-extended initialier-list constructor. 230 map(initializer_list<value_type> __l, const allocator_type& __a) 231 : _M_t(_Compare(), _Pair_alloc_type(__a)) 232 { _M_t._M_insert_unique(__l.begin(), __l.end()); } 233 234 /// Allocator-extended range constructor. 235 template<typename _InputIterator> 236 map(_InputIterator __first, _InputIterator __last, 237 const allocator_type& __a) 238 : _M_t(_Compare(), _Pair_alloc_type(__a)) 239 { _M_t._M_insert_unique(__first, __last); } 240 #endif 241 242 /** 243 * @brief Builds a %map from a range. 244 * @param __first An input iterator. 245 * @param __last An input iterator. 246 * 247 * Create a %map consisting of copies of the elements from 248 * [__first,__last). This is linear in N if the range is 249 * already sorted, and NlogN otherwise (where N is 250 * distance(__first,__last)). 251 */ 252 template<typename _InputIterator> 253 map(_InputIterator __first, _InputIterator __last) 254 : _M_t() 255 { _M_t._M_insert_unique(__first, __last); } 256 257 /** 258 * @brief Builds a %map from a range. 259 * @param __first An input iterator. 260 * @param __last An input iterator. 261 * @param __comp A comparison functor. 262 * @param __a An allocator object. 263 * 264 * Create a %map consisting of copies of the elements from 265 * [__first,__last). This is linear in N if the range is 266 * already sorted, and NlogN otherwise (where N is 267 * distance(__first,__last)). 268 */ 269 template<typename _InputIterator> 270 map(_InputIterator __first, _InputIterator __last, 271 const _Compare& __comp, 272 const allocator_type& __a = allocator_type()) 273 : _M_t(__comp, _Pair_alloc_type(__a)) 274 { _M_t._M_insert_unique(__first, __last); } 275 276 // FIXME There is no dtor declared, but we should have something 277 // generated by Doxygen. I don't know what tags to add to this 278 // paragraph to make that happen: 279 /** 280 * The dtor only erases the elements, and note that if the elements 281 * themselves are pointers, the pointed-to memory is not touched in any 282 * way. Managing the pointer is the user's responsibility. 283 */ 284 285 /** 286 * @brief %Map assignment operator. 287 * @param __x A %map of identical element and allocator types. 288 * 289 * All the elements of @a __x are copied, but unlike the copy 290 * constructor, the allocator object is not copied. 291 */ 292 map& 293 operator=(const map& __x) 294 { 295 _M_t = __x._M_t; 296 return *this; 297 } 298 299 #if __cplusplus >= 201103L 300 /** 301 * @brief %Map move assignment operator. 302 * @param __x A %map of identical element and allocator types. 303 * 304 * The contents of @a __x are moved into this map (without copying 305 * if the allocators compare equal or get moved on assignment). 306 * Afterwards @a __x is in a valid, but unspecified state. 307 */ 308 map& 309 operator=(map&& __x) noexcept(_Alloc_traits::_S_nothrow_move()) 310 { 311 if (!_M_t._M_move_assign(__x._M_t)) 312 { 313 // The rvalue's allocator cannot be moved and is not equal, 314 // so we need to individually move each element. 315 clear(); 316 insert(std::__make_move_if_noexcept_iterator(__x.begin()), 317 std::__make_move_if_noexcept_iterator(__x.end())); 318 __x.clear(); 319 } 320 return *this; 321 } 322 323 /** 324 * @brief %Map list assignment operator. 325 * @param __l An initializer_list. 326 * 327 * This function fills a %map with copies of the elements in the 328 * initializer list @a __l. 329 * 330 * Note that the assignment completely changes the %map and 331 * that the resulting %map's size is the same as the number 332 * of elements assigned. Old data may be lost. 333 */ 334 map& 335 operator=(initializer_list<value_type> __l) 336 { 337 this->clear(); 338 this->insert(__l.begin(), __l.end()); 339 return *this; 340 } 341 #endif 342 343 /// Get a copy of the memory allocation object. 344 allocator_type 345 get_allocator() const _GLIBCXX_NOEXCEPT 346 { return allocator_type(_M_t.get_allocator()); } 347 348 // iterators 349 /** 350 * Returns a read/write iterator that points to the first pair in the 351 * %map. 352 * Iteration is done in ascending order according to the keys. 353 */ 354 iterator 355 begin() _GLIBCXX_NOEXCEPT 356 { return _M_t.begin(); } 357 358 /** 359 * Returns a read-only (constant) iterator that points to the first pair 360 * in the %map. Iteration is done in ascending order according to the 361 * keys. 362 */ 363 const_iterator 364 begin() const _GLIBCXX_NOEXCEPT 365 { return _M_t.begin(); } 366 367 /** 368 * Returns a read/write iterator that points one past the last 369 * pair in the %map. Iteration is done in ascending order 370 * according to the keys. 371 */ 372 iterator 373 end() _GLIBCXX_NOEXCEPT 374 { return _M_t.end(); } 375 376 /** 377 * Returns a read-only (constant) iterator that points one past the last 378 * pair in the %map. Iteration is done in ascending order according to 379 * the keys. 380 */ 381 const_iterator 382 end() const _GLIBCXX_NOEXCEPT 383 { return _M_t.end(); } 384 385 /** 386 * Returns a read/write reverse iterator that points to the last pair in 387 * the %map. Iteration is done in descending order according to the 388 * keys. 389 */ 390 reverse_iterator 391 rbegin() _GLIBCXX_NOEXCEPT 392 { return _M_t.rbegin(); } 393 394 /** 395 * Returns a read-only (constant) reverse iterator that points to the 396 * last pair in the %map. Iteration is done in descending order 397 * according to the keys. 398 */ 399 const_reverse_iterator 400 rbegin() const _GLIBCXX_NOEXCEPT 401 { return _M_t.rbegin(); } 402 403 /** 404 * Returns a read/write reverse iterator that points to one before the 405 * first pair in the %map. Iteration is done in descending order 406 * according to the keys. 407 */ 408 reverse_iterator 409 rend() _GLIBCXX_NOEXCEPT 410 { return _M_t.rend(); } 411 412 /** 413 * Returns a read-only (constant) reverse iterator that points to one 414 * before the first pair in the %map. Iteration is done in descending 415 * order according to the keys. 416 */ 417 const_reverse_iterator 418 rend() const _GLIBCXX_NOEXCEPT 419 { return _M_t.rend(); } 420 421 #if __cplusplus >= 201103L 422 /** 423 * Returns a read-only (constant) iterator that points to the first pair 424 * in the %map. Iteration is done in ascending order according to the 425 * keys. 426 */ 427 const_iterator 428 cbegin() const noexcept 429 { return _M_t.begin(); } 430 431 /** 432 * Returns a read-only (constant) iterator that points one past the last 433 * pair in the %map. Iteration is done in ascending order according to 434 * the keys. 435 */ 436 const_iterator 437 cend() const noexcept 438 { return _M_t.end(); } 439 440 /** 441 * Returns a read-only (constant) reverse iterator that points to the 442 * last pair in the %map. Iteration is done in descending order 443 * according to the keys. 444 */ 445 const_reverse_iterator 446 crbegin() const noexcept 447 { return _M_t.rbegin(); } 448 449 /** 450 * Returns a read-only (constant) reverse iterator that points to one 451 * before the first pair in the %map. Iteration is done in descending 452 * order according to the keys. 453 */ 454 const_reverse_iterator 455 crend() const noexcept 456 { return _M_t.rend(); } 457 #endif 458 459 // capacity 460 /** Returns true if the %map is empty. (Thus begin() would equal 461 * end().) 462 */ 463 bool 464 empty() const _GLIBCXX_NOEXCEPT 465 { return _M_t.empty(); } 466 467 /** Returns the size of the %map. */ 468 size_type 469 size() const _GLIBCXX_NOEXCEPT 470 { return _M_t.size(); } 471 472 /** Returns the maximum size of the %map. */ 473 size_type 474 max_size() const _GLIBCXX_NOEXCEPT 475 { return _M_t.max_size(); } 476 477 // [23.3.1.2] element access 478 /** 479 * @brief Subscript ( @c [] ) access to %map data. 480 * @param __k The key for which data should be retrieved. 481 * @return A reference to the data of the (key,data) %pair. 482 * 483 * Allows for easy lookup with the subscript ( @c [] ) 484 * operator. Returns data associated with the key specified in 485 * subscript. If the key does not exist, a pair with that key 486 * is created using default values, which is then returned. 487 * 488 * Lookup requires logarithmic time. 489 */ 490 mapped_type& 491 operator[](const key_type& __k) 492 { 493 // concept requirements 494 __glibcxx_function_requires(_DefaultConstructibleConcept<mapped_type>) 495 496 iterator __i = lower_bound(__k); 497 // __i->first is greater than or equivalent to __k. 498 if (__i == end() || key_comp()(__k, (*__i).first)) 499 #if __cplusplus >= 201103L 500 __i = _M_t._M_emplace_hint_unique(__i, std::piecewise_construct, 501 std::tuple<const key_type&>(__k), 502 std::tuple<>()); 503 #else 504 __i = insert(__i, value_type(__k, mapped_type())); 505 #endif 506 return (*__i).second; 507 } 508 509 #if __cplusplus >= 201103L 510 mapped_type& 511 operator[](key_type&& __k) 512 { 513 // concept requirements 514 __glibcxx_function_requires(_DefaultConstructibleConcept<mapped_type>) 515 516 iterator __i = lower_bound(__k); 517 // __i->first is greater than or equivalent to __k. 518 if (__i == end() || key_comp()(__k, (*__i).first)) 519 __i = _M_t._M_emplace_hint_unique(__i, std::piecewise_construct, 520 std::forward_as_tuple(std::move(__k)), 521 std::tuple<>()); 522 return (*__i).second; 523 } 524 #endif 525 526 // _GLIBCXX_RESOLVE_LIB_DEFECTS 527 // DR 464. Suggestion for new member functions in standard containers. 528 /** 529 * @brief Access to %map data. 530 * @param __k The key for which data should be retrieved. 531 * @return A reference to the data whose key is equivalent to @a __k, if 532 * such a data is present in the %map. 533 * @throw std::out_of_range If no such data is present. 534 */ 535 mapped_type& 536 at(const key_type& __k) 537 { 538 iterator __i = lower_bound(__k); 539 if (__i == end() || key_comp()(__k, (*__i).first)) 540 __throw_out_of_range(__N("map::at")); 541 return (*__i).second; 542 } 543 544 const mapped_type& 545 at(const key_type& __k) const 546 { 547 const_iterator __i = lower_bound(__k); 548 if (__i == end() || key_comp()(__k, (*__i).first)) 549 __throw_out_of_range(__N("map::at")); 550 return (*__i).second; 551 } 552 553 // modifiers 554 #if __cplusplus >= 201103L 555 /** 556 * @brief Attempts to build and insert a std::pair into the %map. 557 * 558 * @param __args Arguments used to generate a new pair instance (see 559 * std::piecewise_contruct for passing arguments to each 560 * part of the pair constructor). 561 * 562 * @return A pair, of which the first element is an iterator that points 563 * to the possibly inserted pair, and the second is a bool that 564 * is true if the pair was actually inserted. 565 * 566 * This function attempts to build and insert a (key, value) %pair into 567 * the %map. 568 * A %map relies on unique keys and thus a %pair is only inserted if its 569 * first element (the key) is not already present in the %map. 570 * 571 * Insertion requires logarithmic time. 572 */ 573 template<typename... _Args> 574 std::pair<iterator, bool> 575 emplace(_Args&&... __args) 576 { return _M_t._M_emplace_unique(std::forward<_Args>(__args)...); } 577 578 /** 579 * @brief Attempts to build and insert a std::pair into the %map. 580 * 581 * @param __pos An iterator that serves as a hint as to where the pair 582 * should be inserted. 583 * @param __args Arguments used to generate a new pair instance (see 584 * std::piecewise_contruct for passing arguments to each 585 * part of the pair constructor). 586 * @return An iterator that points to the element with key of the 587 * std::pair built from @a __args (may or may not be that 588 * std::pair). 589 * 590 * This function is not concerned about whether the insertion took place, 591 * and thus does not return a boolean like the single-argument emplace() 592 * does. 593 * Note that the first parameter is only a hint and can potentially 594 * improve the performance of the insertion process. A bad hint would 595 * cause no gains in efficiency. 596 * 597 * See 598 * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html 599 * for more on @a hinting. 600 * 601 * Insertion requires logarithmic time (if the hint is not taken). 602 */ 603 template<typename... _Args> 604 iterator 605 emplace_hint(const_iterator __pos, _Args&&... __args) 606 { 607 return _M_t._M_emplace_hint_unique(__pos, 608 std::forward<_Args>(__args)...); 609 } 610 #endif 611 612 /** 613 * @brief Attempts to insert a std::pair into the %map. 614 615 * @param __x Pair to be inserted (see std::make_pair for easy 616 * creation of pairs). 617 * 618 * @return A pair, of which the first element is an iterator that 619 * points to the possibly inserted pair, and the second is 620 * a bool that is true if the pair was actually inserted. 621 * 622 * This function attempts to insert a (key, value) %pair into the %map. 623 * A %map relies on unique keys and thus a %pair is only inserted if its 624 * first element (the key) is not already present in the %map. 625 * 626 * Insertion requires logarithmic time. 627 */ 628 std::pair<iterator, bool> 629 insert(const value_type& __x) 630 { return _M_t._M_insert_unique(__x); } 631 632 #if __cplusplus >= 201103L 633 template<typename _Pair, typename = typename 634 std::enable_if<std::is_constructible<value_type, 635 _Pair&&>::value>::type> 636 std::pair<iterator, bool> 637 insert(_Pair&& __x) 638 { return _M_t._M_insert_unique(std::forward<_Pair>(__x)); } 639 #endif 640 641 #if __cplusplus >= 201103L 642 /** 643 * @brief Attempts to insert a list of std::pairs into the %map. 644 * @param __list A std::initializer_list<value_type> of pairs to be 645 * inserted. 646 * 647 * Complexity similar to that of the range constructor. 648 */ 649 void 650 insert(std::initializer_list<value_type> __list) 651 { insert(__list.begin(), __list.end()); } 652 #endif 653 654 /** 655 * @brief Attempts to insert a std::pair into the %map. 656 * @param __position An iterator that serves as a hint as to where the 657 * pair should be inserted. 658 * @param __x Pair to be inserted (see std::make_pair for easy creation 659 * of pairs). 660 * @return An iterator that points to the element with key of 661 * @a __x (may or may not be the %pair passed in). 662 * 663 664 * This function is not concerned about whether the insertion 665 * took place, and thus does not return a boolean like the 666 * single-argument insert() does. Note that the first 667 * parameter is only a hint and can potentially improve the 668 * performance of the insertion process. A bad hint would 669 * cause no gains in efficiency. 670 * 671 * See 672 * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html 673 * for more on @a hinting. 674 * 675 * Insertion requires logarithmic time (if the hint is not taken). 676 */ 677 iterator 678 #if __cplusplus >= 201103L 679 insert(const_iterator __position, const value_type& __x) 680 #else 681 insert(iterator __position, const value_type& __x) 682 #endif 683 { return _M_t._M_insert_unique_(__position, __x); } 684 685 #if __cplusplus >= 201103L 686 template<typename _Pair, typename = typename 687 std::enable_if<std::is_constructible<value_type, 688 _Pair&&>::value>::type> 689 iterator 690 insert(const_iterator __position, _Pair&& __x) 691 { return _M_t._M_insert_unique_(__position, 692 std::forward<_Pair>(__x)); } 693 #endif 694 695 /** 696 * @brief Template function that attempts to insert a range of elements. 697 * @param __first Iterator pointing to the start of the range to be 698 * inserted. 699 * @param __last Iterator pointing to the end of the range. 700 * 701 * Complexity similar to that of the range constructor. 702 */ 703 template<typename _InputIterator> 704 void 705 insert(_InputIterator __first, _InputIterator __last) 706 { _M_t._M_insert_unique(__first, __last); } 707 708 #if __cplusplus >= 201103L 709 // _GLIBCXX_RESOLVE_LIB_DEFECTS 710 // DR 130. Associative erase should return an iterator. 711 /** 712 * @brief Erases an element from a %map. 713 * @param __position An iterator pointing to the element to be erased. 714 * @return An iterator pointing to the element immediately following 715 * @a position prior to the element being erased. If no such 716 * element exists, end() is returned. 717 * 718 * This function erases an element, pointed to by the given 719 * iterator, from a %map. Note that this function only erases 720 * the element, and that if the element is itself a pointer, 721 * the pointed-to memory is not touched in any way. Managing 722 * the pointer is the user's responsibility. 723 */ 724 iterator 725 erase(const_iterator __position) 726 { return _M_t.erase(__position); } 727 728 // LWG 2059 729 _GLIBCXX_ABI_TAG_CXX11 730 iterator 731 erase(iterator __position) 732 { return _M_t.erase(__position); } 733 #else 734 /** 735 * @brief Erases an element from a %map. 736 * @param __position An iterator pointing to the element to be erased. 737 * 738 * This function erases an element, pointed to by the given 739 * iterator, from a %map. Note that this function only erases 740 * the element, and that if the element is itself a pointer, 741 * the pointed-to memory is not touched in any way. Managing 742 * the pointer is the user's responsibility. 743 */ 744 void 745 erase(iterator __position) 746 { _M_t.erase(__position); } 747 #endif 748 749 /** 750 * @brief Erases elements according to the provided key. 751 * @param __x Key of element to be erased. 752 * @return The number of elements erased. 753 * 754 * This function erases all the elements located by the given key from 755 * a %map. 756 * Note that this function only erases the element, and that if 757 * the element is itself a pointer, the pointed-to memory is not touched 758 * in any way. Managing the pointer is the user's responsibility. 759 */ 760 size_type 761 erase(const key_type& __x) 762 { return _M_t.erase(__x); } 763 764 #if __cplusplus >= 201103L 765 // _GLIBCXX_RESOLVE_LIB_DEFECTS 766 // DR 130. Associative erase should return an iterator. 767 /** 768 * @brief Erases a [first,last) range of elements from a %map. 769 * @param __first Iterator pointing to the start of the range to be 770 * erased. 771 * @param __last Iterator pointing to the end of the range to 772 * be erased. 773 * @return The iterator @a __last. 774 * 775 * This function erases a sequence of elements from a %map. 776 * Note that this function only erases the element, and that if 777 * the element is itself a pointer, the pointed-to memory is not touched 778 * in any way. Managing the pointer is the user's responsibility. 779 */ 780 iterator 781 erase(const_iterator __first, const_iterator __last) 782 { return _M_t.erase(__first, __last); } 783 #else 784 /** 785 * @brief Erases a [__first,__last) range of elements from a %map. 786 * @param __first Iterator pointing to the start of the range to be 787 * erased. 788 * @param __last Iterator pointing to the end of the range to 789 * be erased. 790 * 791 * This function erases a sequence of elements from a %map. 792 * Note that this function only erases the element, and that if 793 * the element is itself a pointer, the pointed-to memory is not touched 794 * in any way. Managing the pointer is the user's responsibility. 795 */ 796 void 797 erase(iterator __first, iterator __last) 798 { _M_t.erase(__first, __last); } 799 #endif 800 801 /** 802 * @brief Swaps data with another %map. 803 * @param __x A %map of the same element and allocator types. 804 * 805 * This exchanges the elements between two maps in constant 806 * time. (It is only swapping a pointer, an integer, and an 807 * instance of the @c Compare type (which itself is often 808 * stateless and empty), so it should be quite fast.) Note 809 * that the global std::swap() function is specialized such 810 * that std::swap(m1,m2) will feed to this function. 811 */ 812 void 813 swap(map& __x) 814 #if __cplusplus >= 201103L 815 noexcept(_Alloc_traits::_S_nothrow_swap()) 816 #endif 817 { _M_t.swap(__x._M_t); } 818 819 /** 820 * Erases all elements in a %map. Note that this function only 821 * erases the elements, and that if the elements themselves are 822 * pointers, the pointed-to memory is not touched in any way. 823 * Managing the pointer is the user's responsibility. 824 */ 825 void 826 clear() _GLIBCXX_NOEXCEPT 827 { _M_t.clear(); } 828 829 // observers 830 /** 831 * Returns the key comparison object out of which the %map was 832 * constructed. 833 */ 834 key_compare 835 key_comp() const 836 { return _M_t.key_comp(); } 837 838 /** 839 * Returns a value comparison object, built from the key comparison 840 * object out of which the %map was constructed. 841 */ 842 value_compare 843 value_comp() const 844 { return value_compare(_M_t.key_comp()); } 845 846 // [23.3.1.3] map operations 847 /** 848 * @brief Tries to locate an element in a %map. 849 * @param __x Key of (key, value) %pair to be located. 850 * @return Iterator pointing to sought-after element, or end() if not 851 * found. 852 * 853 * This function takes a key and tries to locate the element with which 854 * the key matches. If successful the function returns an iterator 855 * pointing to the sought after %pair. If unsuccessful it returns the 856 * past-the-end ( @c end() ) iterator. 857 */ 858 iterator 859 find(const key_type& __x) 860 { return _M_t.find(__x); } 861 862 /** 863 * @brief Tries to locate an element in a %map. 864 * @param __x Key of (key, value) %pair to be located. 865 * @return Read-only (constant) iterator pointing to sought-after 866 * element, or end() if not found. 867 * 868 * This function takes a key and tries to locate the element with which 869 * the key matches. If successful the function returns a constant 870 * iterator pointing to the sought after %pair. If unsuccessful it 871 * returns the past-the-end ( @c end() ) iterator. 872 */ 873 const_iterator 874 find(const key_type& __x) const 875 { return _M_t.find(__x); } 876 877 /** 878 * @brief Finds the number of elements with given key. 879 * @param __x Key of (key, value) pairs to be located. 880 * @return Number of elements with specified key. 881 * 882 * This function only makes sense for multimaps; for map the result will 883 * either be 0 (not present) or 1 (present). 884 */ 885 size_type 886 count(const key_type& __x) const 887 { return _M_t.find(__x) == _M_t.end() ? 0 : 1; } 888 889 /** 890 * @brief Finds the beginning of a subsequence matching given key. 891 * @param __x Key of (key, value) pair to be located. 892 * @return Iterator pointing to first element equal to or greater 893 * than key, or end(). 894 * 895 * This function returns the first element of a subsequence of elements 896 * that matches the given key. If unsuccessful it returns an iterator 897 * pointing to the first element that has a greater value than given key 898 * or end() if no such element exists. 899 */ 900 iterator 901 lower_bound(const key_type& __x) 902 { return _M_t.lower_bound(__x); } 903 904 /** 905 * @brief Finds the beginning of a subsequence matching given key. 906 * @param __x Key of (key, value) pair to be located. 907 * @return Read-only (constant) iterator pointing to first element 908 * equal to or greater than key, or end(). 909 * 910 * This function returns the first element of a subsequence of elements 911 * that matches the given key. If unsuccessful it returns an iterator 912 * pointing to the first element that has a greater value than given key 913 * or end() if no such element exists. 914 */ 915 const_iterator 916 lower_bound(const key_type& __x) const 917 { return _M_t.lower_bound(__x); } 918 919 /** 920 * @brief Finds the end of a subsequence matching given key. 921 * @param __x Key of (key, value) pair to be located. 922 * @return Iterator pointing to the first element 923 * greater than key, or end(). 924 */ 925 iterator 926 upper_bound(const key_type& __x) 927 { return _M_t.upper_bound(__x); } 928 929 /** 930 * @brief Finds the end of a subsequence matching given key. 931 * @param __x Key of (key, value) pair to be located. 932 * @return Read-only (constant) iterator pointing to first iterator 933 * greater than key, or end(). 934 */ 935 const_iterator 936 upper_bound(const key_type& __x) const 937 { return _M_t.upper_bound(__x); } 938 939 /** 940 * @brief Finds a subsequence matching given key. 941 * @param __x Key of (key, value) pairs to be located. 942 * @return Pair of iterators that possibly points to the subsequence 943 * matching given key. 944 * 945 * This function is equivalent to 946 * @code 947 * std::make_pair(c.lower_bound(val), 948 * c.upper_bound(val)) 949 * @endcode 950 * (but is faster than making the calls separately). 951 * 952 * This function probably only makes sense for multimaps. 953 */ 954 std::pair<iterator, iterator> 955 equal_range(const key_type& __x) 956 { return _M_t.equal_range(__x); } 957 958 /** 959 * @brief Finds a subsequence matching given key. 960 * @param __x Key of (key, value) pairs to be located. 961 * @return Pair of read-only (constant) iterators that possibly points 962 * to the subsequence matching given key. 963 * 964 * This function is equivalent to 965 * @code 966 * std::make_pair(c.lower_bound(val), 967 * c.upper_bound(val)) 968 * @endcode 969 * (but is faster than making the calls separately). 970 * 971 * This function probably only makes sense for multimaps. 972 */ 973 std::pair<const_iterator, const_iterator> 974 equal_range(const key_type& __x) const 975 { return _M_t.equal_range(__x); } 976 977 template<typename _K1, typename _T1, typename _C1, typename _A1> 978 friend bool 979 operator==(const map<_K1, _T1, _C1, _A1>&, 980 const map<_K1, _T1, _C1, _A1>&); 981 982 template<typename _K1, typename _T1, typename _C1, typename _A1> 983 friend bool 984 operator<(const map<_K1, _T1, _C1, _A1>&, 985 const map<_K1, _T1, _C1, _A1>&); 986 }; 987 988 /** 989 * @brief Map equality comparison. 990 * @param __x A %map. 991 * @param __y A %map of the same type as @a x. 992 * @return True iff the size and elements of the maps are equal. 993 * 994 * This is an equivalence relation. It is linear in the size of the 995 * maps. Maps are considered equivalent if their sizes are equal, 996 * and if corresponding elements compare equal. 997 */ 998 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 999 inline bool 1000 operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x, 1001 const map<_Key, _Tp, _Compare, _Alloc>& __y) 1002 { return __x._M_t == __y._M_t; } 1003 1004 /** 1005 * @brief Map ordering relation. 1006 * @param __x A %map. 1007 * @param __y A %map of the same type as @a x. 1008 * @return True iff @a x is lexicographically less than @a y. 1009 * 1010 * This is a total ordering relation. It is linear in the size of the 1011 * maps. The elements must be comparable with @c <. 1012 * 1013 * See std::lexicographical_compare() for how the determination is made. 1014 */ 1015 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 1016 inline bool 1017 operator<(const map<_Key, _Tp, _Compare, _Alloc>& __x, 1018 const map<_Key, _Tp, _Compare, _Alloc>& __y) 1019 { return __x._M_t < __y._M_t; } 1020 1021 /// Based on operator== 1022 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 1023 inline bool 1024 operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x, 1025 const map<_Key, _Tp, _Compare, _Alloc>& __y) 1026 { return !(__x == __y); } 1027 1028 /// Based on operator< 1029 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 1030 inline bool 1031 operator>(const map<_Key, _Tp, _Compare, _Alloc>& __x, 1032 const map<_Key, _Tp, _Compare, _Alloc>& __y) 1033 { return __y < __x; } 1034 1035 /// Based on operator< 1036 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 1037 inline bool 1038 operator<=(const map<_Key, _Tp, _Compare, _Alloc>& __x, 1039 const map<_Key, _Tp, _Compare, _Alloc>& __y) 1040 { return !(__y < __x); } 1041 1042 /// Based on operator< 1043 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 1044 inline bool 1045 operator>=(const map<_Key, _Tp, _Compare, _Alloc>& __x, 1046 const map<_Key, _Tp, _Compare, _Alloc>& __y) 1047 { return !(__x < __y); } 1048 1049 /// See std::map::swap(). 1050 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 1051 inline void 1052 swap(map<_Key, _Tp, _Compare, _Alloc>& __x, 1053 map<_Key, _Tp, _Compare, _Alloc>& __y) 1054 { __x.swap(__y); } 1055 1056 _GLIBCXX_END_NAMESPACE_CONTAINER 1057 } // namespace std 1058 1059 #endif /* _STL_MAP_H */ 1060
