1 // Map implementation -*- C++ -*- 2 3 // Copyright (C) 2001-2016 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 _GLIBCXX_NOEXCEPT_IF( 164 is_nothrow_default_constructible<allocator_type>::value 165 && is_nothrow_default_constructible<key_compare>::value) 166 : _M_t() { } 167 168 /** 169 * @brief Creates a %map with no elements. 170 * @param __comp A comparison object. 171 * @param __a An allocator object. 172 */ 173 explicit 174 map(const _Compare& __comp, 175 const allocator_type& __a = allocator_type()) 176 : _M_t(__comp, _Pair_alloc_type(__a)) { } 177 178 /** 179 * @brief %Map copy constructor. 180 * @param __x A %map of identical element and allocator types. 181 * 182 * The newly-created %map uses a copy of the allocation object 183 * used by @a __x. 184 */ 185 map(const map& __x) 186 : _M_t(__x._M_t) { } 187 188 #if __cplusplus >= 201103L 189 /** 190 * @brief %Map move constructor. 191 * @param __x A %map of identical element and allocator types. 192 * 193 * The newly-created %map contains the exact contents of @a __x. 194 * The contents of @a __x are a valid, but unspecified %map. 195 */ 196 map(map&& __x) 197 noexcept(is_nothrow_copy_constructible<_Compare>::value) 198 : _M_t(std::move(__x._M_t)) { } 199 200 /** 201 * @brief Builds a %map from an initializer_list. 202 * @param __l An initializer_list. 203 * @param __comp A comparison object. 204 * @param __a An allocator object. 205 * 206 * Create a %map consisting of copies of the elements in the 207 * initializer_list @a __l. 208 * This is linear in N if the range is already sorted, and NlogN 209 * otherwise (where N is @a __l.size()). 210 */ 211 map(initializer_list<value_type> __l, 212 const _Compare& __comp = _Compare(), 213 const allocator_type& __a = allocator_type()) 214 : _M_t(__comp, _Pair_alloc_type(__a)) 215 { _M_t._M_insert_unique(__l.begin(), __l.end()); } 216 217 /// Allocator-extended default constructor. 218 explicit 219 map(const allocator_type& __a) 220 : _M_t(_Compare(), _Pair_alloc_type(__a)) { } 221 222 /// Allocator-extended copy constructor. 223 map(const map& __m, const allocator_type& __a) 224 : _M_t(__m._M_t, _Pair_alloc_type(__a)) { } 225 226 /// Allocator-extended move constructor. 227 map(map&& __m, const allocator_type& __a) 228 noexcept(is_nothrow_copy_constructible<_Compare>::value 229 && _Alloc_traits::_S_always_equal()) 230 : _M_t(std::move(__m._M_t), _Pair_alloc_type(__a)) { } 231 232 /// Allocator-extended initialier-list constructor. 233 map(initializer_list<value_type> __l, const allocator_type& __a) 234 : _M_t(_Compare(), _Pair_alloc_type(__a)) 235 { _M_t._M_insert_unique(__l.begin(), __l.end()); } 236 237 /// Allocator-extended range constructor. 238 template<typename _InputIterator> 239 map(_InputIterator __first, _InputIterator __last, 240 const allocator_type& __a) 241 : _M_t(_Compare(), _Pair_alloc_type(__a)) 242 { _M_t._M_insert_unique(__first, __last); } 243 #endif 244 245 /** 246 * @brief Builds a %map from a range. 247 * @param __first An input iterator. 248 * @param __last An input iterator. 249 * 250 * Create a %map consisting of copies of the elements from 251 * [__first,__last). This is linear in N if the range is 252 * already sorted, and NlogN otherwise (where N is 253 * distance(__first,__last)). 254 */ 255 template<typename _InputIterator> 256 map(_InputIterator __first, _InputIterator __last) 257 : _M_t() 258 { _M_t._M_insert_unique(__first, __last); } 259 260 /** 261 * @brief Builds a %map from a range. 262 * @param __first An input iterator. 263 * @param __last An input iterator. 264 * @param __comp A comparison functor. 265 * @param __a An allocator object. 266 * 267 * Create a %map consisting of copies of the elements from 268 * [__first,__last). This is linear in N if the range is 269 * already sorted, and NlogN otherwise (where N is 270 * distance(__first,__last)). 271 */ 272 template<typename _InputIterator> 273 map(_InputIterator __first, _InputIterator __last, 274 const _Compare& __comp, 275 const allocator_type& __a = allocator_type()) 276 : _M_t(__comp, _Pair_alloc_type(__a)) 277 { _M_t._M_insert_unique(__first, __last); } 278 279 // FIXME There is no dtor declared, but we should have something 280 // generated by Doxygen. I don't know what tags to add to this 281 // paragraph to make that happen: 282 /** 283 * The dtor only erases the elements, and note that if the elements 284 * themselves are pointers, the pointed-to memory is not touched in any 285 * way. Managing the pointer is the user's responsibility. 286 */ 287 288 /** 289 * @brief %Map assignment operator. 290 * @param __x A %map of identical element and allocator types. 291 * 292 * All the elements of @a __x are copied, but unlike the copy 293 * constructor, the allocator object is not copied. 294 */ 295 map& 296 operator=(const map& __x) 297 { 298 _M_t = __x._M_t; 299 return *this; 300 } 301 302 #if __cplusplus >= 201103L 303 /// Move assignment operator. 304 map& 305 operator=(map&&) = default; 306 307 /** 308 * @brief %Map list assignment operator. 309 * @param __l An initializer_list. 310 * 311 * This function fills a %map with copies of the elements in the 312 * initializer list @a __l. 313 * 314 * Note that the assignment completely changes the %map and 315 * that the resulting %map's size is the same as the number 316 * of elements assigned. Old data may be lost. 317 */ 318 map& 319 operator=(initializer_list<value_type> __l) 320 { 321 _M_t._M_assign_unique(__l.begin(), __l.end()); 322 return *this; 323 } 324 #endif 325 326 /// Get a copy of the memory allocation object. 327 allocator_type 328 get_allocator() const _GLIBCXX_NOEXCEPT 329 { return allocator_type(_M_t.get_allocator()); } 330 331 // iterators 332 /** 333 * Returns a read/write iterator that points to the first pair in the 334 * %map. 335 * Iteration is done in ascending order according to the keys. 336 */ 337 iterator 338 begin() _GLIBCXX_NOEXCEPT 339 { return _M_t.begin(); } 340 341 /** 342 * Returns a read-only (constant) iterator that points to the first pair 343 * in the %map. Iteration is done in ascending order according to the 344 * keys. 345 */ 346 const_iterator 347 begin() const _GLIBCXX_NOEXCEPT 348 { return _M_t.begin(); } 349 350 /** 351 * Returns a read/write iterator that points one past the last 352 * pair in the %map. Iteration is done in ascending order 353 * according to the keys. 354 */ 355 iterator 356 end() _GLIBCXX_NOEXCEPT 357 { return _M_t.end(); } 358 359 /** 360 * Returns a read-only (constant) iterator that points one past the last 361 * pair in the %map. Iteration is done in ascending order according to 362 * the keys. 363 */ 364 const_iterator 365 end() const _GLIBCXX_NOEXCEPT 366 { return _M_t.end(); } 367 368 /** 369 * Returns a read/write reverse iterator that points to the last pair in 370 * the %map. Iteration is done in descending order according to the 371 * keys. 372 */ 373 reverse_iterator 374 rbegin() _GLIBCXX_NOEXCEPT 375 { return _M_t.rbegin(); } 376 377 /** 378 * Returns a read-only (constant) reverse iterator that points to the 379 * last pair in the %map. Iteration is done in descending order 380 * according to the keys. 381 */ 382 const_reverse_iterator 383 rbegin() const _GLIBCXX_NOEXCEPT 384 { return _M_t.rbegin(); } 385 386 /** 387 * Returns a read/write reverse iterator that points to one before the 388 * first pair in the %map. Iteration is done in descending order 389 * according to the keys. 390 */ 391 reverse_iterator 392 rend() _GLIBCXX_NOEXCEPT 393 { return _M_t.rend(); } 394 395 /** 396 * Returns a read-only (constant) reverse iterator that points to one 397 * before the first pair in the %map. Iteration is done in descending 398 * order according to the keys. 399 */ 400 const_reverse_iterator 401 rend() const _GLIBCXX_NOEXCEPT 402 { return _M_t.rend(); } 403 404 #if __cplusplus >= 201103L 405 /** 406 * Returns a read-only (constant) iterator that points to the first pair 407 * in the %map. Iteration is done in ascending order according to the 408 * keys. 409 */ 410 const_iterator 411 cbegin() const noexcept 412 { return _M_t.begin(); } 413 414 /** 415 * Returns a read-only (constant) iterator that points one past the last 416 * pair in the %map. Iteration is done in ascending order according to 417 * the keys. 418 */ 419 const_iterator 420 cend() const noexcept 421 { return _M_t.end(); } 422 423 /** 424 * Returns a read-only (constant) reverse iterator that points to the 425 * last pair in the %map. Iteration is done in descending order 426 * according to the keys. 427 */ 428 const_reverse_iterator 429 crbegin() const noexcept 430 { return _M_t.rbegin(); } 431 432 /** 433 * Returns a read-only (constant) reverse iterator that points to one 434 * before the first pair in the %map. Iteration is done in descending 435 * order according to the keys. 436 */ 437 const_reverse_iterator 438 crend() const noexcept 439 { return _M_t.rend(); } 440 #endif 441 442 // capacity 443 /** Returns true if the %map is empty. (Thus begin() would equal 444 * end().) 445 */ 446 bool 447 empty() const _GLIBCXX_NOEXCEPT 448 { return _M_t.empty(); } 449 450 /** Returns the size of the %map. */ 451 size_type 452 size() const _GLIBCXX_NOEXCEPT 453 { return _M_t.size(); } 454 455 /** Returns the maximum size of the %map. */ 456 size_type 457 max_size() const _GLIBCXX_NOEXCEPT 458 { return _M_t.max_size(); } 459 460 // [23.3.1.2] element access 461 /** 462 * @brief Subscript ( @c [] ) access to %map data. 463 * @param __k The key for which data should be retrieved. 464 * @return A reference to the data of the (key,data) %pair. 465 * 466 * Allows for easy lookup with the subscript ( @c [] ) 467 * operator. Returns data associated with the key specified in 468 * subscript. If the key does not exist, a pair with that key 469 * is created using default values, which is then returned. 470 * 471 * Lookup requires logarithmic time. 472 */ 473 mapped_type& 474 operator[](const key_type& __k) 475 { 476 // concept requirements 477 __glibcxx_function_requires(_DefaultConstructibleConcept<mapped_type>) 478 479 iterator __i = lower_bound(__k); 480 // __i->first is greater than or equivalent to __k. 481 if (__i == end() || key_comp()(__k, (*__i).first)) 482 #if __cplusplus >= 201103L 483 __i = _M_t._M_emplace_hint_unique(__i, std::piecewise_construct, 484 std::tuple<const key_type&>(__k), 485 std::tuple<>()); 486 #else 487 __i = insert(__i, value_type(__k, mapped_type())); 488 #endif 489 return (*__i).second; 490 } 491 492 #if __cplusplus >= 201103L 493 mapped_type& 494 operator[](key_type&& __k) 495 { 496 // concept requirements 497 __glibcxx_function_requires(_DefaultConstructibleConcept<mapped_type>) 498 499 iterator __i = lower_bound(__k); 500 // __i->first is greater than or equivalent to __k. 501 if (__i == end() || key_comp()(__k, (*__i).first)) 502 __i = _M_t._M_emplace_hint_unique(__i, std::piecewise_construct, 503 std::forward_as_tuple(std::move(__k)), 504 std::tuple<>()); 505 return (*__i).second; 506 } 507 #endif 508 509 // _GLIBCXX_RESOLVE_LIB_DEFECTS 510 // DR 464. Suggestion for new member functions in standard containers. 511 /** 512 * @brief Access to %map data. 513 * @param __k The key for which data should be retrieved. 514 * @return A reference to the data whose key is equivalent to @a __k, if 515 * such a data is present in the %map. 516 * @throw std::out_of_range If no such data is present. 517 */ 518 mapped_type& 519 at(const key_type& __k) 520 { 521 iterator __i = lower_bound(__k); 522 if (__i == end() || key_comp()(__k, (*__i).first)) 523 __throw_out_of_range(__N("map::at")); 524 return (*__i).second; 525 } 526 527 const mapped_type& 528 at(const key_type& __k) const 529 { 530 const_iterator __i = lower_bound(__k); 531 if (__i == end() || key_comp()(__k, (*__i).first)) 532 __throw_out_of_range(__N("map::at")); 533 return (*__i).second; 534 } 535 536 // modifiers 537 #if __cplusplus >= 201103L 538 /** 539 * @brief Attempts to build and insert a std::pair into the %map. 540 * 541 * @param __args Arguments used to generate a new pair instance (see 542 * std::piecewise_contruct for passing arguments to each 543 * part of the pair constructor). 544 * 545 * @return A pair, of which the first element is an iterator that points 546 * to the possibly inserted pair, and the second is a bool that 547 * is true if the pair was actually inserted. 548 * 549 * This function attempts to build and insert a (key, value) %pair into 550 * the %map. 551 * A %map relies on unique keys and thus a %pair is only inserted if its 552 * first element (the key) is not already present in the %map. 553 * 554 * Insertion requires logarithmic time. 555 */ 556 template<typename... _Args> 557 std::pair<iterator, bool> 558 emplace(_Args&&... __args) 559 { return _M_t._M_emplace_unique(std::forward<_Args>(__args)...); } 560 561 /** 562 * @brief Attempts to build and insert a std::pair into the %map. 563 * 564 * @param __pos An iterator that serves as a hint as to where the pair 565 * should be inserted. 566 * @param __args Arguments used to generate a new pair instance (see 567 * std::piecewise_contruct for passing arguments to each 568 * part of the pair constructor). 569 * @return An iterator that points to the element with key of the 570 * std::pair built from @a __args (may or may not be that 571 * std::pair). 572 * 573 * This function is not concerned about whether the insertion took place, 574 * and thus does not return a boolean like the single-argument emplace() 575 * does. 576 * Note that the first parameter is only a hint and can potentially 577 * improve the performance of the insertion process. A bad hint would 578 * cause no gains in efficiency. 579 * 580 * See 581 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints 582 * for more on @a hinting. 583 * 584 * Insertion requires logarithmic time (if the hint is not taken). 585 */ 586 template<typename... _Args> 587 iterator 588 emplace_hint(const_iterator __pos, _Args&&... __args) 589 { 590 return _M_t._M_emplace_hint_unique(__pos, 591 std::forward<_Args>(__args)...); 592 } 593 #endif 594 595 #if __cplusplus > 201402L 596 #define __cpp_lib_map_try_emplace 201411 597 /** 598 * @brief Attempts to build and insert a std::pair into the %map. 599 * 600 * @param __k Key to use for finding a possibly existing pair in 601 * the map. 602 * @param __args Arguments used to generate the .second for a new pair 603 * instance. 604 * 605 * @return A pair, of which the first element is an iterator that points 606 * to the possibly inserted pair, and the second is a bool that 607 * is true if the pair was actually inserted. 608 * 609 * This function attempts to build and insert a (key, value) %pair into 610 * the %map. 611 * A %map relies on unique keys and thus a %pair is only inserted if its 612 * first element (the key) is not already present in the %map. 613 * If a %pair is not inserted, this function has no effect. 614 * 615 * Insertion requires logarithmic time. 616 */ 617 template <typename... _Args> 618 pair<iterator, bool> 619 try_emplace(const key_type& __k, _Args&&... __args) 620 { 621 iterator __i = lower_bound(__k); 622 if (__i == end() || key_comp()(__k, (*__i).first)) 623 { 624 __i = emplace_hint(__i, std::piecewise_construct, 625 std::forward_as_tuple(__k), 626 std::forward_as_tuple( 627 std::forward<_Args>(__args)...)); 628 return {__i, true}; 629 } 630 return {__i, false}; 631 } 632 633 // move-capable overload 634 template <typename... _Args> 635 pair<iterator, bool> 636 try_emplace(key_type&& __k, _Args&&... __args) 637 { 638 iterator __i = lower_bound(__k); 639 if (__i == end() || key_comp()(__k, (*__i).first)) 640 { 641 __i = emplace_hint(__i, std::piecewise_construct, 642 std::forward_as_tuple(std::move(__k)), 643 std::forward_as_tuple( 644 std::forward<_Args>(__args)...)); 645 return {__i, true}; 646 } 647 return {__i, false}; 648 } 649 650 /** 651 * @brief Attempts to build and insert a std::pair into the %map. 652 * 653 * @param __hint An iterator that serves as a hint as to where the 654 * pair should be inserted. 655 * @param __k Key to use for finding a possibly existing pair in 656 * the map. 657 * @param __args Arguments used to generate the .second for a new pair 658 * instance. 659 * @return An iterator that points to the element with key of the 660 * std::pair built from @a __args (may or may not be that 661 * std::pair). 662 * 663 * This function is not concerned about whether the insertion took place, 664 * and thus does not return a boolean like the single-argument 665 * try_emplace() does. However, if insertion did not take place, 666 * this function has no effect. 667 * Note that the first parameter is only a hint and can potentially 668 * improve the performance of the insertion process. A bad hint would 669 * cause no gains in efficiency. 670 * 671 * See 672 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints 673 * for more on @a hinting. 674 * 675 * Insertion requires logarithmic time (if the hint is not taken). 676 */ 677 template <typename... _Args> 678 iterator 679 try_emplace(const_iterator __hint, const key_type& __k, 680 _Args&&... __args) 681 { 682 iterator __i; 683 auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k); 684 if (__true_hint.second) 685 __i = emplace_hint(iterator(__true_hint.second), 686 std::piecewise_construct, 687 std::forward_as_tuple(__k), 688 std::forward_as_tuple( 689 std::forward<_Args>(__args)...)); 690 else 691 __i = iterator(__true_hint.first); 692 return __i; 693 } 694 695 // move-capable overload 696 template <typename... _Args> 697 iterator 698 try_emplace(const_iterator __hint, key_type&& __k, _Args&&... __args) 699 { 700 iterator __i; 701 auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k); 702 if (__true_hint.second) 703 __i = emplace_hint(iterator(__true_hint.second), 704 std::piecewise_construct, 705 std::forward_as_tuple(std::move(__k)), 706 std::forward_as_tuple( 707 std::forward<_Args>(__args)...)); 708 else 709 __i = iterator(__true_hint.first); 710 return __i; 711 } 712 #endif 713 714 /** 715 * @brief Attempts to insert a std::pair into the %map. 716 717 * @param __x Pair to be inserted (see std::make_pair for easy 718 * creation of pairs). 719 * 720 * @return A pair, of which the first element is an iterator that 721 * points to the possibly inserted pair, and the second is 722 * a bool that is true if the pair was actually inserted. 723 * 724 * This function attempts to insert a (key, value) %pair into the %map. 725 * A %map relies on unique keys and thus a %pair is only inserted if its 726 * first element (the key) is not already present in the %map. 727 * 728 * Insertion requires logarithmic time. 729 */ 730 std::pair<iterator, bool> 731 insert(const value_type& __x) 732 { return _M_t._M_insert_unique(__x); } 733 734 #if __cplusplus >= 201103L 735 template<typename _Pair, typename = typename 736 std::enable_if<std::is_constructible<value_type, 737 _Pair&&>::value>::type> 738 std::pair<iterator, bool> 739 insert(_Pair&& __x) 740 { return _M_t._M_insert_unique(std::forward<_Pair>(__x)); } 741 #endif 742 743 #if __cplusplus >= 201103L 744 /** 745 * @brief Attempts to insert a list of std::pairs into the %map. 746 * @param __list A std::initializer_list<value_type> of pairs to be 747 * inserted. 748 * 749 * Complexity similar to that of the range constructor. 750 */ 751 void 752 insert(std::initializer_list<value_type> __list) 753 { insert(__list.begin(), __list.end()); } 754 #endif 755 756 /** 757 * @brief Attempts to insert a std::pair into the %map. 758 * @param __position An iterator that serves as a hint as to where the 759 * pair should be inserted. 760 * @param __x Pair to be inserted (see std::make_pair for easy creation 761 * of pairs). 762 * @return An iterator that points to the element with key of 763 * @a __x (may or may not be the %pair passed in). 764 * 765 766 * This function is not concerned about whether the insertion 767 * took place, and thus does not return a boolean like the 768 * single-argument insert() does. Note that the first 769 * parameter is only a hint and can potentially improve the 770 * performance of the insertion process. A bad hint would 771 * cause no gains in efficiency. 772 * 773 * See 774 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints 775 * for more on @a hinting. 776 * 777 * Insertion requires logarithmic time (if the hint is not taken). 778 */ 779 iterator 780 #if __cplusplus >= 201103L 781 insert(const_iterator __position, const value_type& __x) 782 #else 783 insert(iterator __position, const value_type& __x) 784 #endif 785 { return _M_t._M_insert_unique_(__position, __x); } 786 787 #if __cplusplus >= 201103L 788 template<typename _Pair, typename = typename 789 std::enable_if<std::is_constructible<value_type, 790 _Pair&&>::value>::type> 791 iterator 792 insert(const_iterator __position, _Pair&& __x) 793 { return _M_t._M_insert_unique_(__position, 794 std::forward<_Pair>(__x)); } 795 #endif 796 797 /** 798 * @brief Template function that attempts to insert a range of elements. 799 * @param __first Iterator pointing to the start of the range to be 800 * inserted. 801 * @param __last Iterator pointing to the end of the range. 802 * 803 * Complexity similar to that of the range constructor. 804 */ 805 template<typename _InputIterator> 806 void 807 insert(_InputIterator __first, _InputIterator __last) 808 { _M_t._M_insert_unique(__first, __last); } 809 810 #if __cplusplus > 201402L 811 #define __cpp_lib_map_insertion 201411 812 /** 813 * @brief Attempts to insert or assign a std::pair into the %map. 814 * @param __k Key to use for finding a possibly existing pair in 815 * the map. 816 * @param __obj Argument used to generate the .second for a pair 817 * instance. 818 * 819 * @return A pair, of which the first element is an iterator that 820 * points to the possibly inserted pair, and the second is 821 * a bool that is true if the pair was actually inserted. 822 * 823 * This function attempts to insert a (key, value) %pair into the %map. 824 * A %map relies on unique keys and thus a %pair is only inserted if its 825 * first element (the key) is not already present in the %map. 826 * If the %pair was already in the %map, the .second of the %pair 827 * is assigned from __obj. 828 * 829 * Insertion requires logarithmic time. 830 */ 831 template <typename _Obj> 832 pair<iterator, bool> 833 insert_or_assign(const key_type& __k, _Obj&& __obj) 834 { 835 iterator __i = lower_bound(__k); 836 if (__i == end() || key_comp()(__k, (*__i).first)) 837 { 838 __i = emplace_hint(__i, std::piecewise_construct, 839 std::forward_as_tuple(__k), 840 std::forward_as_tuple( 841 std::forward<_Obj>(__obj))); 842 return {__i, true}; 843 } 844 (*__i).second = std::forward<_Obj>(__obj); 845 return {__i, false}; 846 } 847 848 // move-capable overload 849 template <typename _Obj> 850 pair<iterator, bool> 851 insert_or_assign(key_type&& __k, _Obj&& __obj) 852 { 853 iterator __i = lower_bound(__k); 854 if (__i == end() || key_comp()(__k, (*__i).first)) 855 { 856 __i = emplace_hint(__i, std::piecewise_construct, 857 std::forward_as_tuple(std::move(__k)), 858 std::forward_as_tuple( 859 std::forward<_Obj>(__obj))); 860 return {__i, true}; 861 } 862 (*__i).second = std::forward<_Obj>(__obj); 863 return {__i, false}; 864 } 865 866 /** 867 * @brief Attempts to insert or assign a std::pair into the %map. 868 * @param __hint An iterator that serves as a hint as to where the 869 * pair should be inserted. 870 * @param __k Key to use for finding a possibly existing pair in 871 * the map. 872 * @param __obj Argument used to generate the .second for a pair 873 * instance. 874 * 875 * @return An iterator that points to the element with key of 876 * @a __x (may or may not be the %pair passed in). 877 * 878 * This function attempts to insert a (key, value) %pair into the %map. 879 * A %map relies on unique keys and thus a %pair is only inserted if its 880 * first element (the key) is not already present in the %map. 881 * If the %pair was already in the %map, the .second of the %pair 882 * is assigned from __obj. 883 * 884 * Insertion requires logarithmic time. 885 */ 886 template <typename _Obj> 887 iterator 888 insert_or_assign(const_iterator __hint, 889 const key_type& __k, _Obj&& __obj) 890 { 891 iterator __i; 892 auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k); 893 if (__true_hint.second) 894 { 895 return emplace_hint(iterator(__true_hint.second), 896 std::piecewise_construct, 897 std::forward_as_tuple(__k), 898 std::forward_as_tuple( 899 std::forward<_Obj>(__obj))); 900 } 901 __i = iterator(__true_hint.first); 902 (*__i).second = std::forward<_Obj>(__obj); 903 return __i; 904 } 905 906 // move-capable overload 907 template <typename _Obj> 908 iterator 909 insert_or_assign(const_iterator __hint, key_type&& __k, _Obj&& __obj) 910 { 911 iterator __i; 912 auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k); 913 if (__true_hint.second) 914 { 915 return emplace_hint(iterator(__true_hint.second), 916 std::piecewise_construct, 917 std::forward_as_tuple(std::move(__k)), 918 std::forward_as_tuple( 919 std::forward<_Obj>(__obj))); 920 } 921 __i = iterator(__true_hint.first); 922 (*__i).second = std::forward<_Obj>(__obj); 923 return __i; 924 } 925 #endif 926 927 #if __cplusplus >= 201103L 928 // _GLIBCXX_RESOLVE_LIB_DEFECTS 929 // DR 130. Associative erase should return an iterator. 930 /** 931 * @brief Erases an element from a %map. 932 * @param __position An iterator pointing to the element to be erased. 933 * @return An iterator pointing to the element immediately following 934 * @a position prior to the element being erased. If no such 935 * element exists, end() is returned. 936 * 937 * This function erases an element, pointed to by the given 938 * iterator, from a %map. Note that this function only erases 939 * the element, and that if the element is itself a pointer, 940 * the pointed-to memory is not touched in any way. Managing 941 * the pointer is the user's responsibility. 942 */ 943 iterator 944 erase(const_iterator __position) 945 { return _M_t.erase(__position); } 946 947 // LWG 2059 948 _GLIBCXX_ABI_TAG_CXX11 949 iterator 950 erase(iterator __position) 951 { return _M_t.erase(__position); } 952 #else 953 /** 954 * @brief Erases an element from a %map. 955 * @param __position An iterator pointing to the element to be erased. 956 * 957 * This function erases an element, pointed to by the given 958 * iterator, from a %map. Note that this function only erases 959 * the element, and that if the element is itself a pointer, 960 * the pointed-to memory is not touched in any way. Managing 961 * the pointer is the user's responsibility. 962 */ 963 void 964 erase(iterator __position) 965 { _M_t.erase(__position); } 966 #endif 967 968 /** 969 * @brief Erases elements according to the provided key. 970 * @param __x Key of element to be erased. 971 * @return The number of elements erased. 972 * 973 * This function erases all the elements located by the given key from 974 * a %map. 975 * Note that this function only erases the element, and that if 976 * the element is itself a pointer, the pointed-to memory is not touched 977 * in any way. Managing the pointer is the user's responsibility. 978 */ 979 size_type 980 erase(const key_type& __x) 981 { return _M_t.erase(__x); } 982 983 #if __cplusplus >= 201103L 984 // _GLIBCXX_RESOLVE_LIB_DEFECTS 985 // DR 130. Associative erase should return an iterator. 986 /** 987 * @brief Erases a [first,last) range of elements from a %map. 988 * @param __first Iterator pointing to the start of the range to be 989 * erased. 990 * @param __last Iterator pointing to the end of the range to 991 * be erased. 992 * @return The iterator @a __last. 993 * 994 * This function erases a sequence of elements from a %map. 995 * Note that this function only erases the element, and that if 996 * the element is itself a pointer, the pointed-to memory is not touched 997 * in any way. Managing the pointer is the user's responsibility. 998 */ 999 iterator 1000 erase(const_iterator __first, const_iterator __last) 1001 { return _M_t.erase(__first, __last); } 1002 #else 1003 /** 1004 * @brief Erases a [__first,__last) range of elements from a %map. 1005 * @param __first Iterator pointing to the start of the range to be 1006 * erased. 1007 * @param __last Iterator pointing to the end of the range to 1008 * be erased. 1009 * 1010 * This function erases a sequence of elements from a %map. 1011 * Note that this function only erases the element, and that if 1012 * the element is itself a pointer, the pointed-to memory is not touched 1013 * in any way. Managing the pointer is the user's responsibility. 1014 */ 1015 void 1016 erase(iterator __first, iterator __last) 1017 { _M_t.erase(__first, __last); } 1018 #endif 1019 1020 /** 1021 * @brief Swaps data with another %map. 1022 * @param __x A %map of the same element and allocator types. 1023 * 1024 * This exchanges the elements between two maps in constant 1025 * time. (It is only swapping a pointer, an integer, and an 1026 * instance of the @c Compare type (which itself is often 1027 * stateless and empty), so it should be quite fast.) Note 1028 * that the global std::swap() function is specialized such 1029 * that std::swap(m1,m2) will feed to this function. 1030 */ 1031 void 1032 swap(map& __x) 1033 _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable<_Compare>::value) 1034 { _M_t.swap(__x._M_t); } 1035 1036 /** 1037 * Erases all elements in a %map. Note that this function only 1038 * erases the elements, and that if the elements themselves are 1039 * pointers, the pointed-to memory is not touched in any way. 1040 * Managing the pointer is the user's responsibility. 1041 */ 1042 void 1043 clear() _GLIBCXX_NOEXCEPT 1044 { _M_t.clear(); } 1045 1046 // observers 1047 /** 1048 * Returns the key comparison object out of which the %map was 1049 * constructed. 1050 */ 1051 key_compare 1052 key_comp() const 1053 { return _M_t.key_comp(); } 1054 1055 /** 1056 * Returns a value comparison object, built from the key comparison 1057 * object out of which the %map was constructed. 1058 */ 1059 value_compare 1060 value_comp() const 1061 { return value_compare(_M_t.key_comp()); } 1062 1063 // [23.3.1.3] map operations 1064 1065 //@{ 1066 /** 1067 * @brief Tries to locate an element in a %map. 1068 * @param __x Key of (key, value) %pair to be located. 1069 * @return Iterator pointing to sought-after element, or end() if not 1070 * found. 1071 * 1072 * This function takes a key and tries to locate the element with which 1073 * the key matches. If successful the function returns an iterator 1074 * pointing to the sought after %pair. If unsuccessful it returns the 1075 * past-the-end ( @c end() ) iterator. 1076 */ 1077 1078 iterator 1079 find(const key_type& __x) 1080 { return _M_t.find(__x); } 1081 1082 #if __cplusplus > 201103L 1083 template<typename _Kt> 1084 auto 1085 find(const _Kt& __x) -> decltype(_M_t._M_find_tr(__x)) 1086 { return _M_t._M_find_tr(__x); } 1087 #endif 1088 //@} 1089 1090 //@{ 1091 /** 1092 * @brief Tries to locate an element in a %map. 1093 * @param __x Key of (key, value) %pair to be located. 1094 * @return Read-only (constant) iterator pointing to sought-after 1095 * element, or end() if not found. 1096 * 1097 * This function takes a key and tries to locate the element with which 1098 * the key matches. If successful the function returns a constant 1099 * iterator pointing to the sought after %pair. If unsuccessful it 1100 * returns the past-the-end ( @c end() ) iterator. 1101 */ 1102 1103 const_iterator 1104 find(const key_type& __x) const 1105 { return _M_t.find(__x); } 1106 1107 #if __cplusplus > 201103L 1108 template<typename _Kt> 1109 auto 1110 find(const _Kt& __x) const -> decltype(_M_t._M_find_tr(__x)) 1111 { return _M_t._M_find_tr(__x); } 1112 #endif 1113 //@} 1114 1115 //@{ 1116 /** 1117 * @brief Finds the number of elements with given key. 1118 * @param __x Key of (key, value) pairs to be located. 1119 * @return Number of elements with specified key. 1120 * 1121 * This function only makes sense for multimaps; for map the result will 1122 * either be 0 (not present) or 1 (present). 1123 */ 1124 size_type 1125 count(const key_type& __x) const 1126 { return _M_t.find(__x) == _M_t.end() ? 0 : 1; } 1127 1128 #if __cplusplus > 201103L 1129 template<typename _Kt> 1130 auto 1131 count(const _Kt& __x) const -> decltype(_M_t._M_count_tr(__x)) 1132 { return _M_t._M_count_tr(__x); } 1133 #endif 1134 //@} 1135 1136 //@{ 1137 /** 1138 * @brief Finds the beginning of a subsequence matching given key. 1139 * @param __x Key of (key, value) pair to be located. 1140 * @return Iterator pointing to first element equal to or greater 1141 * than key, or end(). 1142 * 1143 * This function returns the first element of a subsequence of elements 1144 * that matches the given key. If unsuccessful it returns an iterator 1145 * pointing to the first element that has a greater value than given key 1146 * or end() if no such element exists. 1147 */ 1148 iterator 1149 lower_bound(const key_type& __x) 1150 { return _M_t.lower_bound(__x); } 1151 1152 #if __cplusplus > 201103L 1153 template<typename _Kt> 1154 auto 1155 lower_bound(const _Kt& __x) 1156 -> decltype(iterator(_M_t._M_lower_bound_tr(__x))) 1157 { return iterator(_M_t._M_lower_bound_tr(__x)); } 1158 #endif 1159 //@} 1160 1161 //@{ 1162 /** 1163 * @brief Finds the beginning of a subsequence matching given key. 1164 * @param __x Key of (key, value) pair to be located. 1165 * @return Read-only (constant) iterator pointing to first element 1166 * equal to or greater than key, or end(). 1167 * 1168 * This function returns the first element of a subsequence of elements 1169 * that matches the given key. If unsuccessful it returns an iterator 1170 * pointing to the first element that has a greater value than given key 1171 * or end() if no such element exists. 1172 */ 1173 const_iterator 1174 lower_bound(const key_type& __x) const 1175 { return _M_t.lower_bound(__x); } 1176 1177 #if __cplusplus > 201103L 1178 template<typename _Kt> 1179 auto 1180 lower_bound(const _Kt& __x) const 1181 -> decltype(const_iterator(_M_t._M_lower_bound_tr(__x))) 1182 { return const_iterator(_M_t._M_lower_bound_tr(__x)); } 1183 #endif 1184 //@} 1185 1186 //@{ 1187 /** 1188 * @brief Finds the end of a subsequence matching given key. 1189 * @param __x Key of (key, value) pair to be located. 1190 * @return Iterator pointing to the first element 1191 * greater than key, or end(). 1192 */ 1193 iterator 1194 upper_bound(const key_type& __x) 1195 { return _M_t.upper_bound(__x); } 1196 1197 #if __cplusplus > 201103L 1198 template<typename _Kt> 1199 auto 1200 upper_bound(const _Kt& __x) 1201 -> decltype(iterator(_M_t._M_upper_bound_tr(__x))) 1202 { return iterator(_M_t._M_upper_bound_tr(__x)); } 1203 #endif 1204 //@} 1205 1206 //@{ 1207 /** 1208 * @brief Finds the end of a subsequence matching given key. 1209 * @param __x Key of (key, value) pair to be located. 1210 * @return Read-only (constant) iterator pointing to first iterator 1211 * greater than key, or end(). 1212 */ 1213 const_iterator 1214 upper_bound(const key_type& __x) const 1215 { return _M_t.upper_bound(__x); } 1216 1217 #if __cplusplus > 201103L 1218 template<typename _Kt> 1219 auto 1220 upper_bound(const _Kt& __x) const 1221 -> decltype(const_iterator(_M_t._M_upper_bound_tr(__x))) 1222 { return const_iterator(_M_t._M_upper_bound_tr(__x)); } 1223 #endif 1224 //@} 1225 1226 //@{ 1227 /** 1228 * @brief Finds a subsequence matching given key. 1229 * @param __x Key of (key, value) pairs to be located. 1230 * @return Pair of iterators that possibly points to the subsequence 1231 * matching given key. 1232 * 1233 * This function is equivalent to 1234 * @code 1235 * std::make_pair(c.lower_bound(val), 1236 * c.upper_bound(val)) 1237 * @endcode 1238 * (but is faster than making the calls separately). 1239 * 1240 * This function probably only makes sense for multimaps. 1241 */ 1242 std::pair<iterator, iterator> 1243 equal_range(const key_type& __x) 1244 { return _M_t.equal_range(__x); } 1245 1246 #if __cplusplus > 201103L 1247 template<typename _Kt> 1248 auto 1249 equal_range(const _Kt& __x) 1250 -> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x))) 1251 { return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); } 1252 #endif 1253 //@} 1254 1255 //@{ 1256 /** 1257 * @brief Finds a subsequence matching given key. 1258 * @param __x Key of (key, value) pairs to be located. 1259 * @return Pair of read-only (constant) iterators that possibly points 1260 * to the subsequence matching given key. 1261 * 1262 * This function is equivalent to 1263 * @code 1264 * std::make_pair(c.lower_bound(val), 1265 * c.upper_bound(val)) 1266 * @endcode 1267 * (but is faster than making the calls separately). 1268 * 1269 * This function probably only makes sense for multimaps. 1270 */ 1271 std::pair<const_iterator, const_iterator> 1272 equal_range(const key_type& __x) const 1273 { return _M_t.equal_range(__x); } 1274 1275 #if __cplusplus > 201103L 1276 template<typename _Kt> 1277 auto 1278 equal_range(const _Kt& __x) const 1279 -> decltype(pair<const_iterator, const_iterator>( 1280 _M_t._M_equal_range_tr(__x))) 1281 { 1282 return pair<const_iterator, const_iterator>( 1283 _M_t._M_equal_range_tr(__x)); 1284 } 1285 #endif 1286 //@} 1287 1288 template<typename _K1, typename _T1, typename _C1, typename _A1> 1289 friend bool 1290 operator==(const map<_K1, _T1, _C1, _A1>&, 1291 const map<_K1, _T1, _C1, _A1>&); 1292 1293 template<typename _K1, typename _T1, typename _C1, typename _A1> 1294 friend bool 1295 operator<(const map<_K1, _T1, _C1, _A1>&, 1296 const map<_K1, _T1, _C1, _A1>&); 1297 }; 1298 1299 /** 1300 * @brief Map equality comparison. 1301 * @param __x A %map. 1302 * @param __y A %map of the same type as @a x. 1303 * @return True iff the size and elements of the maps are equal. 1304 * 1305 * This is an equivalence relation. It is linear in the size of the 1306 * maps. Maps are considered equivalent if their sizes are equal, 1307 * and if corresponding elements compare equal. 1308 */ 1309 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 1310 inline bool 1311 operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x, 1312 const map<_Key, _Tp, _Compare, _Alloc>& __y) 1313 { return __x._M_t == __y._M_t; } 1314 1315 /** 1316 * @brief Map ordering relation. 1317 * @param __x A %map. 1318 * @param __y A %map of the same type as @a x. 1319 * @return True iff @a x is lexicographically less than @a y. 1320 * 1321 * This is a total ordering relation. It is linear in the size of the 1322 * maps. The elements must be comparable with @c <. 1323 * 1324 * See std::lexicographical_compare() for how the determination is made. 1325 */ 1326 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 1327 inline bool 1328 operator<(const map<_Key, _Tp, _Compare, _Alloc>& __x, 1329 const map<_Key, _Tp, _Compare, _Alloc>& __y) 1330 { return __x._M_t < __y._M_t; } 1331 1332 /// Based on operator== 1333 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 1334 inline bool 1335 operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x, 1336 const map<_Key, _Tp, _Compare, _Alloc>& __y) 1337 { return !(__x == __y); } 1338 1339 /// Based on operator< 1340 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 1341 inline bool 1342 operator>(const map<_Key, _Tp, _Compare, _Alloc>& __x, 1343 const map<_Key, _Tp, _Compare, _Alloc>& __y) 1344 { return __y < __x; } 1345 1346 /// Based on operator< 1347 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 1348 inline bool 1349 operator<=(const map<_Key, _Tp, _Compare, _Alloc>& __x, 1350 const map<_Key, _Tp, _Compare, _Alloc>& __y) 1351 { return !(__y < __x); } 1352 1353 /// Based on operator< 1354 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 1355 inline bool 1356 operator>=(const map<_Key, _Tp, _Compare, _Alloc>& __x, 1357 const map<_Key, _Tp, _Compare, _Alloc>& __y) 1358 { return !(__x < __y); } 1359 1360 /// See std::map::swap(). 1361 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc> 1362 inline void 1363 swap(map<_Key, _Tp, _Compare, _Alloc>& __x, 1364 map<_Key, _Tp, _Compare, _Alloc>& __y) 1365 _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y))) 1366 { __x.swap(__y); } 1367 1368 _GLIBCXX_END_NAMESPACE_CONTAINER 1369 } // namespace std 1370 1371 #endif /* _STL_MAP_H */ 1372