1 // Map implementation -*- C++ -*-
2
3 // Copyright (C) 2001-2022 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
_GLIBCXX_VISIBILITY(default)66 namespace std _GLIBCXX_VISIBILITY(default)
67 {
68 _GLIBCXX_BEGIN_NAMESPACE_VERSION
69 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
70
71 template <typename _Key, typename _Tp, typename _Compare, typename _Alloc>
72 class multimap;
73
74 /**
75 * @brief A standard container made up of (key,value) pairs, which can be
76 * retrieved based on a key, in logarithmic time.
77 *
78 * @ingroup associative_containers
79 * @headerfile map
80 * @since C++98
81 *
82 * @tparam _Key Type of key objects.
83 * @tparam _Tp Type of mapped objects.
84 * @tparam _Compare Comparison function object type, defaults to less<_Key>.
85 * @tparam _Alloc Allocator type, defaults to
86 * allocator<pair<const _Key, _Tp>.
87 *
88 * Meets the requirements of a <a href="tables.html#65">container</a>, a
89 * <a href="tables.html#66">reversible container</a>, and an
90 * <a href="tables.html#69">associative container</a> (using unique keys).
91 * For a @c map<Key,T> the key_type is Key, the mapped_type is T, and the
92 * value_type is std::pair<const Key,T>.
93 *
94 * Maps support bidirectional iterators.
95 *
96 * The private tree data is declared exactly the same way for map and
97 * multimap; the distinction is made entirely in how the tree functions are
98 * called (*_unique versus *_equal, same as the standard).
99 */
100 template <typename _Key, typename _Tp, typename _Compare = std::less<_Key>,
101 typename _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
102 class map
103 {
104 public:
105 typedef _Key key_type;
106 typedef _Tp mapped_type;
107 typedef std::pair<const _Key, _Tp> value_type;
108 typedef _Compare key_compare;
109 typedef _Alloc allocator_type;
110
111 private:
112 #ifdef _GLIBCXX_CONCEPT_CHECKS
113 // concept requirements
114 typedef typename _Alloc::value_type _Alloc_value_type;
115 # if __cplusplus < 201103L
116 __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
117 # endif
118 __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
119 _BinaryFunctionConcept)
120 __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept)
121 #endif
122
123 #if __cplusplus >= 201103L
124 #if __cplusplus > 201703L || defined __STRICT_ANSI__
125 static_assert(is_same<typename _Alloc::value_type, value_type>::value,
126 "std::map must have the same value_type as its allocator");
127 #endif
128 #endif
129
130 public:
131 #pragma GCC diagnostic push
132 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
133 class value_compare
134 : public std::binary_function<value_type, value_type, bool>
135 {
136 friend class map<_Key, _Tp, _Compare, _Alloc>;
137 protected:
138 _Compare comp;
139
140 value_compare(_Compare __c)
141 : comp(__c) { }
142
143 public:
144 bool operator()(const value_type& __x, const value_type& __y) const
145 { return comp(__x.first, __y.first); }
146 };
147 #pragma GCC diagnostic pop
148
149 private:
150 /// This turns a red-black tree into a [multi]map.
151 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
152 rebind<value_type>::other _Pair_alloc_type;
153
154 typedef _Rb_tree<key_type, value_type, _Select1st<value_type>,
155 key_compare, _Pair_alloc_type> _Rep_type;
156
157 /// The actual tree structure.
158 _Rep_type _M_t;
159
160 typedef __gnu_cxx::__alloc_traits<_Pair_alloc_type> _Alloc_traits;
161
162 #if __cplusplus >= 201703L
163 template<typename _Up, typename _Vp = remove_reference_t<_Up>>
164 static constexpr bool __usable_key
165 = __or_v<is_same<const _Vp, const _Key>,
166 __and_<is_scalar<_Vp>, is_scalar<_Key>>>;
167 #endif
168
169 public:
170 // many of these are specified differently in ISO, but the following are
171 // "functionally equivalent"
172 typedef typename _Alloc_traits::pointer pointer;
173 typedef typename _Alloc_traits::const_pointer const_pointer;
174 typedef typename _Alloc_traits::reference reference;
175 typedef typename _Alloc_traits::const_reference const_reference;
176 typedef typename _Rep_type::iterator iterator;
177 typedef typename _Rep_type::const_iterator const_iterator;
178 typedef typename _Rep_type::size_type size_type;
179 typedef typename _Rep_type::difference_type difference_type;
180 typedef typename _Rep_type::reverse_iterator reverse_iterator;
181 typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
182
183 #if __cplusplus > 201402L
184 using node_type = typename _Rep_type::node_type;
185 using insert_return_type = typename _Rep_type::insert_return_type;
186 #endif
187
188 // [23.3.1.1] construct/copy/destroy
189 // (get_allocator() is also listed in this section)
190
191 /**
192 * @brief Default constructor creates no elements.
193 */
194 #if __cplusplus < 201103L
195 map() : _M_t() { }
196 #else
197 map() = default;
198 #endif
199
200 /**
201 * @brief Creates a %map with no elements.
202 * @param __comp A comparison object.
203 * @param __a An allocator object.
204 */
205 explicit
206 map(const _Compare& __comp,
207 const allocator_type& __a = allocator_type())
208 : _M_t(__comp, _Pair_alloc_type(__a)) { }
209
210 /**
211 * @brief %Map copy constructor.
212 *
213 * Whether the allocator is copied depends on the allocator traits.
214 */
215 #if __cplusplus < 201103L
216 map(const map& __x)
217 : _M_t(__x._M_t) { }
218 #else
219 map(const map&) = default;
220
221 /**
222 * @brief %Map move constructor.
223 *
224 * The newly-created %map contains the exact contents of the moved
225 * instance. The moved instance is a valid, but unspecified, %map.
226 */
227 map(map&&) = default;
228
229 /**
230 * @brief Builds a %map from an initializer_list.
231 * @param __l An initializer_list.
232 * @param __comp A comparison object.
233 * @param __a An allocator object.
234 *
235 * Create a %map consisting of copies of the elements in the
236 * initializer_list @a __l.
237 * This is linear in N if the range is already sorted, and NlogN
238 * otherwise (where N is @a __l.size()).
239 */
240 map(initializer_list<value_type> __l,
241 const _Compare& __comp = _Compare(),
242 const allocator_type& __a = allocator_type())
243 : _M_t(__comp, _Pair_alloc_type(__a))
244 { _M_t._M_insert_range_unique(__l.begin(), __l.end()); }
245
246 /// Allocator-extended default constructor.
247 explicit
248 map(const allocator_type& __a)
249 : _M_t(_Pair_alloc_type(__a)) { }
250
251 /// Allocator-extended copy constructor.
252 map(const map& __m, const __type_identity_t<allocator_type>& __a)
253 : _M_t(__m._M_t, _Pair_alloc_type(__a)) { }
254
255 /// Allocator-extended move constructor.
256 map(map&& __m, const __type_identity_t<allocator_type>& __a)
257 noexcept(is_nothrow_copy_constructible<_Compare>::value
258 && _Alloc_traits::_S_always_equal())
259 : _M_t(std::move(__m._M_t), _Pair_alloc_type(__a)) { }
260
261 /// Allocator-extended initialier-list constructor.
262 map(initializer_list<value_type> __l, const allocator_type& __a)
263 : _M_t(_Pair_alloc_type(__a))
264 { _M_t._M_insert_range_unique(__l.begin(), __l.end()); }
265
266 /// Allocator-extended range constructor.
267 template<typename _InputIterator>
268 map(_InputIterator __first, _InputIterator __last,
269 const allocator_type& __a)
270 : _M_t(_Pair_alloc_type(__a))
271 { _M_t._M_insert_range_unique(__first, __last); }
272 #endif
273
274 /**
275 * @brief Builds a %map from a range.
276 * @param __first An input iterator.
277 * @param __last An input iterator.
278 *
279 * Create a %map consisting of copies of the elements from
280 * [__first,__last). This is linear in N if the range is
281 * already sorted, and NlogN otherwise (where N is
282 * distance(__first,__last)).
283 */
284 template<typename _InputIterator>
285 map(_InputIterator __first, _InputIterator __last)
286 : _M_t()
287 { _M_t._M_insert_range_unique(__first, __last); }
288
289 /**
290 * @brief Builds a %map from a range.
291 * @param __first An input iterator.
292 * @param __last An input iterator.
293 * @param __comp A comparison functor.
294 * @param __a An allocator object.
295 *
296 * Create a %map consisting of copies of the elements from
297 * [__first,__last). This is linear in N if the range is
298 * already sorted, and NlogN otherwise (where N is
299 * distance(__first,__last)).
300 */
301 template<typename _InputIterator>
302 map(_InputIterator __first, _InputIterator __last,
303 const _Compare& __comp,
304 const allocator_type& __a = allocator_type())
305 : _M_t(__comp, _Pair_alloc_type(__a))
306 { _M_t._M_insert_range_unique(__first, __last); }
307
308 #if __cplusplus >= 201103L
309 /**
310 * The dtor only erases the elements, and note that if the elements
311 * themselves are pointers, the pointed-to memory is not touched in any
312 * way. Managing the pointer is the user's responsibility.
313 */
314 ~map() = default;
315 #endif
316
317 /**
318 * @brief %Map assignment operator.
319 *
320 * Whether the allocator is copied depends on the allocator traits.
321 */
322 #if __cplusplus < 201103L
323 map&
324 operator=(const map& __x)
325 {
326 _M_t = __x._M_t;
327 return *this;
328 }
329 #else
330 map&
331 operator=(const map&) = default;
332
333 /// Move assignment operator.
334 map&
335 operator=(map&&) = default;
336
337 /**
338 * @brief %Map list assignment operator.
339 * @param __l An initializer_list.
340 *
341 * This function fills a %map with copies of the elements in the
342 * initializer list @a __l.
343 *
344 * Note that the assignment completely changes the %map and
345 * that the resulting %map's size is the same as the number
346 * of elements assigned.
347 */
348 map&
349 operator=(initializer_list<value_type> __l)
350 {
351 _M_t._M_assign_unique(__l.begin(), __l.end());
352 return *this;
353 }
354 #endif
355
356 /// Get a copy of the memory allocation object.
357 allocator_type
358 get_allocator() const _GLIBCXX_NOEXCEPT
359 { return allocator_type(_M_t.get_allocator()); }
360
361 // iterators
362 /**
363 * Returns a read/write iterator that points to the first pair in the
364 * %map.
365 * Iteration is done in ascending order according to the keys.
366 */
367 iterator
368 begin() _GLIBCXX_NOEXCEPT
369 { return _M_t.begin(); }
370
371 /**
372 * Returns a read-only (constant) iterator that points to the first pair
373 * in the %map. Iteration is done in ascending order according to the
374 * keys.
375 */
376 const_iterator
377 begin() const _GLIBCXX_NOEXCEPT
378 { return _M_t.begin(); }
379
380 /**
381 * Returns a read/write iterator that points one past the last
382 * pair in the %map. Iteration is done in ascending order
383 * according to the keys.
384 */
385 iterator
386 end() _GLIBCXX_NOEXCEPT
387 { return _M_t.end(); }
388
389 /**
390 * Returns a read-only (constant) iterator that points one past the last
391 * pair in the %map. Iteration is done in ascending order according to
392 * the keys.
393 */
394 const_iterator
395 end() const _GLIBCXX_NOEXCEPT
396 { return _M_t.end(); }
397
398 /**
399 * Returns a read/write reverse iterator that points to the last pair in
400 * the %map. Iteration is done in descending order according to the
401 * keys.
402 */
403 reverse_iterator
404 rbegin() _GLIBCXX_NOEXCEPT
405 { return _M_t.rbegin(); }
406
407 /**
408 * Returns a read-only (constant) reverse iterator that points to the
409 * last pair in the %map. Iteration is done in descending order
410 * according to the keys.
411 */
412 const_reverse_iterator
413 rbegin() const _GLIBCXX_NOEXCEPT
414 { return _M_t.rbegin(); }
415
416 /**
417 * Returns a read/write reverse iterator that points to one before the
418 * first pair in the %map. Iteration is done in descending order
419 * according to the keys.
420 */
421 reverse_iterator
422 rend() _GLIBCXX_NOEXCEPT
423 { return _M_t.rend(); }
424
425 /**
426 * Returns a read-only (constant) reverse iterator that points to one
427 * before the first pair in the %map. Iteration is done in descending
428 * order according to the keys.
429 */
430 const_reverse_iterator
431 rend() const _GLIBCXX_NOEXCEPT
432 { return _M_t.rend(); }
433
434 #if __cplusplus >= 201103L
435 /**
436 * Returns a read-only (constant) iterator that points to the first pair
437 * in the %map. Iteration is done in ascending order according to the
438 * keys.
439 */
440 const_iterator
441 cbegin() const noexcept
442 { return _M_t.begin(); }
443
444 /**
445 * Returns a read-only (constant) iterator that points one past the last
446 * pair in the %map. Iteration is done in ascending order according to
447 * the keys.
448 */
449 const_iterator
450 cend() const noexcept
451 { return _M_t.end(); }
452
453 /**
454 * Returns a read-only (constant) reverse iterator that points to the
455 * last pair in the %map. Iteration is done in descending order
456 * according to the keys.
457 */
458 const_reverse_iterator
459 crbegin() const noexcept
460 { return _M_t.rbegin(); }
461
462 /**
463 * Returns a read-only (constant) reverse iterator that points to one
464 * before the first pair in the %map. Iteration is done in descending
465 * order according to the keys.
466 */
467 const_reverse_iterator
468 crend() const noexcept
469 { return _M_t.rend(); }
470 #endif
471
472 // capacity
473 /** Returns true if the %map is empty. (Thus begin() would equal
474 * end().)
475 */
476 _GLIBCXX_NODISCARD bool
477 empty() const _GLIBCXX_NOEXCEPT
478 { return _M_t.empty(); }
479
480 /** Returns the size of the %map. */
481 size_type
482 size() const _GLIBCXX_NOEXCEPT
483 { return _M_t.size(); }
484
485 /** Returns the maximum size of the %map. */
486 size_type
487 max_size() const _GLIBCXX_NOEXCEPT
488 { return _M_t.max_size(); }
489
490 // [23.3.1.2] element access
491 /**
492 * @brief Subscript ( @c [] ) access to %map data.
493 * @param __k The key for which data should be retrieved.
494 * @return A reference to the data of the (key,data) %pair.
495 *
496 * Allows for easy lookup with the subscript ( @c [] )
497 * operator. Returns data associated with the key specified in
498 * subscript. If the key does not exist, a pair with that key
499 * is created using default values, which is then returned.
500 *
501 * Lookup requires logarithmic time.
502 */
503 mapped_type&
504 operator[](const key_type& __k)
505 {
506 // concept requirements
507 __glibcxx_function_requires(_DefaultConstructibleConcept<mapped_type>)
508
509 iterator __i = lower_bound(__k);
510 // __i->first is greater than or equivalent to __k.
511 if (__i == end() || key_comp()(__k, (*__i).first))
512 #if __cplusplus >= 201103L
513 __i = _M_t._M_emplace_hint_unique(__i, std::piecewise_construct,
514 std::tuple<const key_type&>(__k),
515 std::tuple<>());
516 #else
517 __i = insert(__i, value_type(__k, mapped_type()));
518 #endif
519 return (*__i).second;
520 }
521
522 #if __cplusplus >= 201103L
523 mapped_type&
524 operator[](key_type&& __k)
525 {
526 // concept requirements
527 __glibcxx_function_requires(_DefaultConstructibleConcept<mapped_type>)
528
529 iterator __i = lower_bound(__k);
530 // __i->first is greater than or equivalent to __k.
531 if (__i == end() || key_comp()(__k, (*__i).first))
532 __i = _M_t._M_emplace_hint_unique(__i, std::piecewise_construct,
533 std::forward_as_tuple(std::move(__k)),
534 std::tuple<>());
535 return (*__i).second;
536 }
537 #endif
538
539 // _GLIBCXX_RESOLVE_LIB_DEFECTS
540 // DR 464. Suggestion for new member functions in standard containers.
541 /**
542 * @brief Access to %map data.
543 * @param __k The key for which data should be retrieved.
544 * @return A reference to the data whose key is equivalent to @a __k, if
545 * such a data is present in the %map.
546 * @throw std::out_of_range If no such data is present.
547 */
548 mapped_type&
549 at(const key_type& __k)
550 {
551 iterator __i = lower_bound(__k);
552 if (__i == end() || key_comp()(__k, (*__i).first))
553 __throw_out_of_range(__N("map::at"));
554 return (*__i).second;
555 }
556
557 const mapped_type&
558 at(const key_type& __k) const
559 {
560 const_iterator __i = lower_bound(__k);
561 if (__i == end() || key_comp()(__k, (*__i).first))
562 __throw_out_of_range(__N("map::at"));
563 return (*__i).second;
564 }
565
566 // modifiers
567 #if __cplusplus >= 201103L
568 /**
569 * @brief Attempts to build and insert a std::pair into the %map.
570 *
571 * @param __args Arguments used to generate a new pair instance (see
572 * std::piecewise_contruct for passing arguments to each
573 * part of the pair constructor).
574 *
575 * @return A pair, of which the first element is an iterator that points
576 * to the possibly inserted pair, and the second is a bool that
577 * is true if the pair was actually inserted.
578 *
579 * This function attempts to build and insert a (key, value) %pair into
580 * the %map.
581 * A %map relies on unique keys and thus a %pair is only inserted if its
582 * first element (the key) is not already present in the %map.
583 *
584 * Insertion requires logarithmic time.
585 */
586 template<typename... _Args>
587 std::pair<iterator, bool>
588 emplace(_Args&&... __args)
589 {
590 #if __cplusplus >= 201703L
591 if constexpr (sizeof...(_Args) == 2)
592 if constexpr (is_same_v<allocator_type, allocator<value_type>>)
593 {
594 auto&& [__a, __v] = pair<_Args&...>(__args...);
595 if constexpr (__usable_key<decltype(__a)>)
596 {
597 const key_type& __k = __a;
598 iterator __i = lower_bound(__k);
599 if (__i == end() || key_comp()(__k, (*__i).first))
600 {
601 __i = emplace_hint(__i, std::forward<_Args>(__args)...);
602 return {__i, true};
603 }
604 return {__i, false};
605 }
606 }
607 #endif
608 return _M_t._M_emplace_unique(std::forward<_Args>(__args)...);
609 }
610
611 /**
612 * @brief Attempts to build and insert a std::pair into the %map.
613 *
614 * @param __pos An iterator that serves as a hint as to where the pair
615 * should be inserted.
616 * @param __args Arguments used to generate a new pair instance (see
617 * std::piecewise_contruct for passing arguments to each
618 * part of the pair constructor).
619 * @return An iterator that points to the element with key of the
620 * std::pair built from @a __args (may or may not be that
621 * std::pair).
622 *
623 * This function is not concerned about whether the insertion took place,
624 * and thus does not return a boolean like the single-argument emplace()
625 * does.
626 * Note that the first parameter is only a hint and can potentially
627 * improve the performance of the insertion process. A bad hint would
628 * cause no gains in efficiency.
629 *
630 * See
631 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
632 * for more on @a hinting.
633 *
634 * Insertion requires logarithmic time (if the hint is not taken).
635 */
636 template<typename... _Args>
637 iterator
638 emplace_hint(const_iterator __pos, _Args&&... __args)
639 {
640 return _M_t._M_emplace_hint_unique(__pos,
641 std::forward<_Args>(__args)...);
642 }
643 #endif
644
645 #if __cplusplus > 201402L
646 /// Extract a node.
647 node_type
648 extract(const_iterator __pos)
649 {
650 __glibcxx_assert(__pos != end());
651 return _M_t.extract(__pos);
652 }
653
654 /// Extract a node.
655 node_type
656 extract(const key_type& __x)
657 { return _M_t.extract(__x); }
658
659 /// Re-insert an extracted node.
660 insert_return_type
661 insert(node_type&& __nh)
662 { return _M_t._M_reinsert_node_unique(std::move(__nh)); }
663
664 /// Re-insert an extracted node.
665 iterator
666 insert(const_iterator __hint, node_type&& __nh)
667 { return _M_t._M_reinsert_node_hint_unique(__hint, std::move(__nh)); }
668
669 template<typename, typename>
670 friend struct std::_Rb_tree_merge_helper;
671
672 template<typename _Cmp2>
673 void
674 merge(map<_Key, _Tp, _Cmp2, _Alloc>& __source)
675 {
676 using _Merge_helper = _Rb_tree_merge_helper<map, _Cmp2>;
677 _M_t._M_merge_unique(_Merge_helper::_S_get_tree(__source));
678 }
679
680 template<typename _Cmp2>
681 void
682 merge(map<_Key, _Tp, _Cmp2, _Alloc>&& __source)
683 { merge(__source); }
684
685 template<typename _Cmp2>
686 void
687 merge(multimap<_Key, _Tp, _Cmp2, _Alloc>& __source)
688 {
689 using _Merge_helper = _Rb_tree_merge_helper<map, _Cmp2>;
690 _M_t._M_merge_unique(_Merge_helper::_S_get_tree(__source));
691 }
692
693 template<typename _Cmp2>
694 void
695 merge(multimap<_Key, _Tp, _Cmp2, _Alloc>&& __source)
696 { merge(__source); }
697 #endif // C++17
698
699 #if __cplusplus > 201402L
700 #define __cpp_lib_map_try_emplace 201411L
701 /**
702 * @brief Attempts to build and insert a std::pair into the %map.
703 *
704 * @param __k Key to use for finding a possibly existing pair in
705 * the map.
706 * @param __args Arguments used to generate the .second for a new pair
707 * instance.
708 *
709 * @return A pair, of which the first element is an iterator that points
710 * to the possibly inserted pair, and the second is a bool that
711 * is true if the pair was actually inserted.
712 *
713 * This function attempts to build and insert a (key, value) %pair into
714 * the %map.
715 * A %map relies on unique keys and thus a %pair is only inserted if its
716 * first element (the key) is not already present in the %map.
717 * If a %pair is not inserted, this function has no effect.
718 *
719 * Insertion requires logarithmic time.
720 */
721 template <typename... _Args>
722 pair<iterator, bool>
723 try_emplace(const key_type& __k, _Args&&... __args)
724 {
725 iterator __i = lower_bound(__k);
726 if (__i == end() || key_comp()(__k, (*__i).first))
727 {
728 __i = emplace_hint(__i, std::piecewise_construct,
729 std::forward_as_tuple(__k),
730 std::forward_as_tuple(
731 std::forward<_Args>(__args)...));
732 return {__i, true};
733 }
734 return {__i, false};
735 }
736
737 // move-capable overload
738 template <typename... _Args>
739 pair<iterator, bool>
740 try_emplace(key_type&& __k, _Args&&... __args)
741 {
742 iterator __i = lower_bound(__k);
743 if (__i == end() || key_comp()(__k, (*__i).first))
744 {
745 __i = emplace_hint(__i, std::piecewise_construct,
746 std::forward_as_tuple(std::move(__k)),
747 std::forward_as_tuple(
748 std::forward<_Args>(__args)...));
749 return {__i, true};
750 }
751 return {__i, false};
752 }
753
754 /**
755 * @brief Attempts to build and insert a std::pair into the %map.
756 *
757 * @param __hint An iterator that serves as a hint as to where the
758 * pair should be inserted.
759 * @param __k Key to use for finding a possibly existing pair in
760 * the map.
761 * @param __args Arguments used to generate the .second for a new pair
762 * instance.
763 * @return An iterator that points to the element with key of the
764 * std::pair built from @a __args (may or may not be that
765 * std::pair).
766 *
767 * This function is not concerned about whether the insertion took place,
768 * and thus does not return a boolean like the single-argument
769 * try_emplace() does. However, if insertion did not take place,
770 * this function has no effect.
771 * Note that the first parameter is only a hint and can potentially
772 * improve the performance of the insertion process. A bad hint would
773 * cause no gains in efficiency.
774 *
775 * See
776 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
777 * for more on @a hinting.
778 *
779 * Insertion requires logarithmic time (if the hint is not taken).
780 */
781 template <typename... _Args>
782 iterator
783 try_emplace(const_iterator __hint, const key_type& __k,
784 _Args&&... __args)
785 {
786 iterator __i;
787 auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k);
788 if (__true_hint.second)
789 __i = emplace_hint(iterator(__true_hint.second),
790 std::piecewise_construct,
791 std::forward_as_tuple(__k),
792 std::forward_as_tuple(
793 std::forward<_Args>(__args)...));
794 else
795 __i = iterator(__true_hint.first);
796 return __i;
797 }
798
799 // move-capable overload
800 template <typename... _Args>
801 iterator
802 try_emplace(const_iterator __hint, key_type&& __k, _Args&&... __args)
803 {
804 iterator __i;
805 auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k);
806 if (__true_hint.second)
807 __i = emplace_hint(iterator(__true_hint.second),
808 std::piecewise_construct,
809 std::forward_as_tuple(std::move(__k)),
810 std::forward_as_tuple(
811 std::forward<_Args>(__args)...));
812 else
813 __i = iterator(__true_hint.first);
814 return __i;
815 }
816 #endif
817
818 /**
819 * @brief Attempts to insert a std::pair into the %map.
820 * @param __x Pair to be inserted (see std::make_pair for easy
821 * creation of pairs).
822 *
823 * @return A pair, of which the first element is an iterator that
824 * points to the possibly inserted pair, and the second is
825 * a bool that is true if the pair was actually inserted.
826 *
827 * This function attempts to insert a (key, value) %pair into the %map.
828 * A %map relies on unique keys and thus a %pair is only inserted if its
829 * first element (the key) is not already present in the %map.
830 *
831 * Insertion requires logarithmic time.
832 * @{
833 */
834 std::pair<iterator, bool>
835 insert(const value_type& __x)
836 { return _M_t._M_insert_unique(__x); }
837
838 #if __cplusplus >= 201103L
839 // _GLIBCXX_RESOLVE_LIB_DEFECTS
840 // 2354. Unnecessary copying when inserting into maps with braced-init
841 std::pair<iterator, bool>
842 insert(value_type&& __x)
843 { return _M_t._M_insert_unique(std::move(__x)); }
844
845 template<typename _Pair>
846 __enable_if_t<is_constructible<value_type, _Pair>::value,
847 pair<iterator, bool>>
848 insert(_Pair&& __x)
849 {
850 #if __cplusplus >= 201703L
851 using _P2 = remove_reference_t<_Pair>;
852 if constexpr (__is_pair<_P2>)
853 if constexpr (is_same_v<allocator_type, allocator<value_type>>)
854 if constexpr (__usable_key<typename _P2::first_type>)
855 {
856 const key_type& __k = __x.first;
857 iterator __i = lower_bound(__k);
858 if (__i == end() || key_comp()(__k, (*__i).first))
859 {
860 __i = emplace_hint(__i, std::forward<_Pair>(__x));
861 return {__i, true};
862 }
863 return {__i, false};
864 }
865 #endif
866 return _M_t._M_emplace_unique(std::forward<_Pair>(__x));
867 }
868 #endif
869 /// @}
870
871 #if __cplusplus >= 201103L
872 /**
873 * @brief Attempts to insert a list of std::pairs into the %map.
874 * @param __list A std::initializer_list<value_type> of pairs to be
875 * inserted.
876 *
877 * Complexity similar to that of the range constructor.
878 */
879 void
880 insert(std::initializer_list<value_type> __list)
881 { insert(__list.begin(), __list.end()); }
882 #endif
883
884 /**
885 * @brief Attempts to insert a std::pair into the %map.
886 * @param __position An iterator that serves as a hint as to where the
887 * pair should be inserted.
888 * @param __x Pair to be inserted (see std::make_pair for easy creation
889 * of pairs).
890 * @return An iterator that points to the element with key of
891 * @a __x (may or may not be the %pair passed in).
892 *
893
894 * This function is not concerned about whether the insertion
895 * took place, and thus does not return a boolean like the
896 * single-argument insert() does. Note that the first
897 * parameter is only a hint and can potentially improve the
898 * performance of the insertion process. A bad hint would
899 * cause no gains in efficiency.
900 *
901 * See
902 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
903 * for more on @a hinting.
904 *
905 * Insertion requires logarithmic time (if the hint is not taken).
906 * @{
907 */
908 iterator
909 #if __cplusplus >= 201103L
910 insert(const_iterator __position, const value_type& __x)
911 #else
912 insert(iterator __position, const value_type& __x)
913 #endif
914 { return _M_t._M_insert_unique_(__position, __x); }
915
916 #if __cplusplus >= 201103L
917 // _GLIBCXX_RESOLVE_LIB_DEFECTS
918 // 2354. Unnecessary copying when inserting into maps with braced-init
919 iterator
920 insert(const_iterator __position, value_type&& __x)
921 { return _M_t._M_insert_unique_(__position, std::move(__x)); }
922
923 template<typename _Pair>
924 __enable_if_t<is_constructible<value_type, _Pair>::value, iterator>
925 insert(const_iterator __position, _Pair&& __x)
926 {
927 return _M_t._M_emplace_hint_unique(__position,
928 std::forward<_Pair>(__x));
929 }
930 #endif
931 /// @}
932
933 /**
934 * @brief Template function that attempts to insert a range of elements.
935 * @param __first Iterator pointing to the start of the range to be
936 * inserted.
937 * @param __last Iterator pointing to the end of the range.
938 *
939 * Complexity similar to that of the range constructor.
940 */
941 template<typename _InputIterator>
942 void
943 insert(_InputIterator __first, _InputIterator __last)
944 { _M_t._M_insert_range_unique(__first, __last); }
945
946 #if __cplusplus > 201402L
947 /**
948 * @brief Attempts to insert or assign a std::pair into the %map.
949 * @param __k Key to use for finding a possibly existing pair in
950 * the map.
951 * @param __obj Argument used to generate the .second for a pair
952 * instance.
953 *
954 * @return A pair, of which the first element is an iterator that
955 * points to the possibly inserted pair, and the second is
956 * a bool that is true if the pair was actually inserted.
957 *
958 * This function attempts to insert a (key, value) %pair into the %map.
959 * A %map relies on unique keys and thus a %pair is only inserted if its
960 * first element (the key) is not already present in the %map.
961 * If the %pair was already in the %map, the .second of the %pair
962 * is assigned from __obj.
963 *
964 * Insertion requires logarithmic time.
965 */
966 template <typename _Obj>
967 pair<iterator, bool>
968 insert_or_assign(const key_type& __k, _Obj&& __obj)
969 {
970 iterator __i = lower_bound(__k);
971 if (__i == end() || key_comp()(__k, (*__i).first))
972 {
973 __i = emplace_hint(__i, std::piecewise_construct,
974 std::forward_as_tuple(__k),
975 std::forward_as_tuple(
976 std::forward<_Obj>(__obj)));
977 return {__i, true};
978 }
979 (*__i).second = std::forward<_Obj>(__obj);
980 return {__i, false};
981 }
982
983 // move-capable overload
984 template <typename _Obj>
985 pair<iterator, bool>
986 insert_or_assign(key_type&& __k, _Obj&& __obj)
987 {
988 iterator __i = lower_bound(__k);
989 if (__i == end() || key_comp()(__k, (*__i).first))
990 {
991 __i = emplace_hint(__i, std::piecewise_construct,
992 std::forward_as_tuple(std::move(__k)),
993 std::forward_as_tuple(
994 std::forward<_Obj>(__obj)));
995 return {__i, true};
996 }
997 (*__i).second = std::forward<_Obj>(__obj);
998 return {__i, false};
999 }
1000
1001 /**
1002 * @brief Attempts to insert or assign a std::pair into the %map.
1003 * @param __hint An iterator that serves as a hint as to where the
1004 * pair should be inserted.
1005 * @param __k Key to use for finding a possibly existing pair in
1006 * the map.
1007 * @param __obj Argument used to generate the .second for a pair
1008 * instance.
1009 *
1010 * @return An iterator that points to the element with key of
1011 * @a __x (may or may not be the %pair passed in).
1012 *
1013 * This function attempts to insert a (key, value) %pair into the %map.
1014 * A %map relies on unique keys and thus a %pair is only inserted if its
1015 * first element (the key) is not already present in the %map.
1016 * If the %pair was already in the %map, the .second of the %pair
1017 * is assigned from __obj.
1018 *
1019 * Insertion requires logarithmic time.
1020 */
1021 template <typename _Obj>
1022 iterator
1023 insert_or_assign(const_iterator __hint,
1024 const key_type& __k, _Obj&& __obj)
1025 {
1026 iterator __i;
1027 auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k);
1028 if (__true_hint.second)
1029 {
1030 return emplace_hint(iterator(__true_hint.second),
1031 std::piecewise_construct,
1032 std::forward_as_tuple(__k),
1033 std::forward_as_tuple(
1034 std::forward<_Obj>(__obj)));
1035 }
1036 __i = iterator(__true_hint.first);
1037 (*__i).second = std::forward<_Obj>(__obj);
1038 return __i;
1039 }
1040
1041 // move-capable overload
1042 template <typename _Obj>
1043 iterator
1044 insert_or_assign(const_iterator __hint, key_type&& __k, _Obj&& __obj)
1045 {
1046 iterator __i;
1047 auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k);
1048 if (__true_hint.second)
1049 {
1050 return emplace_hint(iterator(__true_hint.second),
1051 std::piecewise_construct,
1052 std::forward_as_tuple(std::move(__k)),
1053 std::forward_as_tuple(
1054 std::forward<_Obj>(__obj)));
1055 }
1056 __i = iterator(__true_hint.first);
1057 (*__i).second = std::forward<_Obj>(__obj);
1058 return __i;
1059 }
1060 #endif
1061
1062 #if __cplusplus >= 201103L
1063 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1064 // DR 130. Associative erase should return an iterator.
1065 /**
1066 * @brief Erases an element from a %map.
1067 * @param __position An iterator pointing to the element to be erased.
1068 * @return An iterator pointing to the element immediately following
1069 * @a position prior to the element being erased. If no such
1070 * element exists, end() is returned.
1071 *
1072 * This function erases an element, pointed to by the given
1073 * iterator, from a %map. Note that this function only erases
1074 * the element, and that if the element is itself a pointer,
1075 * the pointed-to memory is not touched in any way. Managing
1076 * the pointer is the user's responsibility.
1077 *
1078 * @{
1079 */
1080 iterator
1081 erase(const_iterator __position)
1082 { return _M_t.erase(__position); }
1083
1084 // LWG 2059
1085 _GLIBCXX_ABI_TAG_CXX11
1086 iterator
1087 erase(iterator __position)
1088 { return _M_t.erase(__position); }
1089 /// @}
1090 #else
1091 /**
1092 * @brief Erases an element from a %map.
1093 * @param __position An iterator pointing to the element to be erased.
1094 *
1095 * This function erases an element, pointed to by the given
1096 * iterator, from a %map. Note that this function only erases
1097 * the element, and that if the element is itself a pointer,
1098 * the pointed-to memory is not touched in any way. Managing
1099 * the pointer is the user's responsibility.
1100 */
1101 void
1102 erase(iterator __position)
1103 { _M_t.erase(__position); }
1104 #endif
1105
1106 /**
1107 * @brief Erases elements according to the provided key.
1108 * @param __x Key of element to be erased.
1109 * @return The number of elements erased.
1110 *
1111 * This function erases all the elements located by the given key from
1112 * a %map.
1113 * Note that this function only erases the element, and that if
1114 * the element is itself a pointer, the pointed-to memory is not touched
1115 * in any way. Managing the pointer is the user's responsibility.
1116 */
1117 size_type
1118 erase(const key_type& __x)
1119 { return _M_t.erase(__x); }
1120
1121 #if __cplusplus >= 201103L
1122 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1123 // DR 130. Associative erase should return an iterator.
1124 /**
1125 * @brief Erases a [first,last) range of elements from a %map.
1126 * @param __first Iterator pointing to the start of the range to be
1127 * erased.
1128 * @param __last Iterator pointing to the end of the range to
1129 * be erased.
1130 * @return The iterator @a __last.
1131 *
1132 * This function erases a sequence of elements from a %map.
1133 * Note that this function only erases the element, and that if
1134 * the element is itself a pointer, the pointed-to memory is not touched
1135 * in any way. Managing the pointer is the user's responsibility.
1136 */
1137 iterator
1138 erase(const_iterator __first, const_iterator __last)
1139 { return _M_t.erase(__first, __last); }
1140 #else
1141 /**
1142 * @brief Erases a [__first,__last) range of elements from a %map.
1143 * @param __first Iterator pointing to the start of the range to be
1144 * erased.
1145 * @param __last Iterator pointing to the end of the range to
1146 * be erased.
1147 *
1148 * This function erases a sequence of elements from a %map.
1149 * Note that this function only erases the element, and that if
1150 * the element is itself a pointer, the pointed-to memory is not touched
1151 * in any way. Managing the pointer is the user's responsibility.
1152 */
1153 void
1154 erase(iterator __first, iterator __last)
1155 { _M_t.erase(__first, __last); }
1156 #endif
1157
1158 /**
1159 * @brief Swaps data with another %map.
1160 * @param __x A %map of the same element and allocator types.
1161 *
1162 * This exchanges the elements between two maps in constant
1163 * time. (It is only swapping a pointer, an integer, and an
1164 * instance of the @c Compare type (which itself is often
1165 * stateless and empty), so it should be quite fast.) Note
1166 * that the global std::swap() function is specialized such
1167 * that std::swap(m1,m2) will feed to this function.
1168 *
1169 * Whether the allocators are swapped depends on the allocator traits.
1170 */
1171 void
1172 swap(map& __x)
1173 _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable<_Compare>::value)
1174 { _M_t.swap(__x._M_t); }
1175
1176 /**
1177 * Erases all elements in a %map. Note that this function only
1178 * erases the elements, and that if the elements themselves are
1179 * pointers, the pointed-to memory is not touched in any way.
1180 * Managing the pointer is the user's responsibility.
1181 */
1182 void
1183 clear() _GLIBCXX_NOEXCEPT
1184 { _M_t.clear(); }
1185
1186 // observers
1187 /**
1188 * Returns the key comparison object out of which the %map was
1189 * constructed.
1190 */
1191 key_compare
1192 key_comp() const
1193 { return _M_t.key_comp(); }
1194
1195 /**
1196 * Returns a value comparison object, built from the key comparison
1197 * object out of which the %map was constructed.
1198 */
1199 value_compare
1200 value_comp() const
1201 { return value_compare(_M_t.key_comp()); }
1202
1203 // [23.3.1.3] map operations
1204
1205 ///@{
1206 /**
1207 * @brief Tries to locate an element in a %map.
1208 * @param __x Key of (key, value) %pair to be located.
1209 * @return Iterator pointing to sought-after element, or end() if not
1210 * found.
1211 *
1212 * This function takes a key and tries to locate the element with which
1213 * the key matches. If successful the function returns an iterator
1214 * pointing to the sought after %pair. If unsuccessful it returns the
1215 * past-the-end ( @c end() ) iterator.
1216 */
1217
1218 iterator
1219 find(const key_type& __x)
1220 { return _M_t.find(__x); }
1221
1222 #if __cplusplus > 201103L
1223 template<typename _Kt>
1224 auto
1225 find(const _Kt& __x) -> decltype(_M_t._M_find_tr(__x))
1226 { return _M_t._M_find_tr(__x); }
1227 #endif
1228 ///@}
1229
1230 ///@{
1231 /**
1232 * @brief Tries to locate an element in a %map.
1233 * @param __x Key of (key, value) %pair to be located.
1234 * @return Read-only (constant) iterator pointing to sought-after
1235 * element, or end() if not found.
1236 *
1237 * This function takes a key and tries to locate the element with which
1238 * the key matches. If successful the function returns a constant
1239 * iterator pointing to the sought after %pair. If unsuccessful it
1240 * returns the past-the-end ( @c end() ) iterator.
1241 */
1242
1243 const_iterator
1244 find(const key_type& __x) const
1245 { return _M_t.find(__x); }
1246
1247 #if __cplusplus > 201103L
1248 template<typename _Kt>
1249 auto
1250 find(const _Kt& __x) const -> decltype(_M_t._M_find_tr(__x))
1251 { return _M_t._M_find_tr(__x); }
1252 #endif
1253 ///@}
1254
1255 ///@{
1256 /**
1257 * @brief Finds the number of elements with given key.
1258 * @param __x Key of (key, value) pairs to be located.
1259 * @return Number of elements with specified key.
1260 *
1261 * This function only makes sense for multimaps; for map the result will
1262 * either be 0 (not present) or 1 (present).
1263 */
1264 size_type
1265 count(const key_type& __x) const
1266 { return _M_t.find(__x) == _M_t.end() ? 0 : 1; }
1267
1268 #if __cplusplus > 201103L
1269 template<typename _Kt>
1270 auto
1271 count(const _Kt& __x) const -> decltype(_M_t._M_count_tr(__x))
1272 { return _M_t._M_count_tr(__x); }
1273 #endif
1274 ///@}
1275
1276 #if __cplusplus > 201703L
1277 ///@{
1278 /**
1279 * @brief Finds whether an element with the given key exists.
1280 * @param __x Key of (key, value) pairs to be located.
1281 * @return True if there is an element with the specified key.
1282 */
1283 bool
1284 contains(const key_type& __x) const
1285 { return _M_t.find(__x) != _M_t.end(); }
1286
1287 template<typename _Kt>
1288 auto
1289 contains(const _Kt& __x) const
1290 -> decltype(_M_t._M_find_tr(__x), void(), true)
1291 { return _M_t._M_find_tr(__x) != _M_t.end(); }
1292 ///@}
1293 #endif
1294
1295 ///@{
1296 /**
1297 * @brief Finds the beginning of a subsequence matching given key.
1298 * @param __x Key of (key, value) pair to be located.
1299 * @return Iterator pointing to first element equal to or greater
1300 * than key, or end().
1301 *
1302 * This function returns the first element of a subsequence of elements
1303 * that matches the given key. If unsuccessful it returns an iterator
1304 * pointing to the first element that has a greater value than given key
1305 * or end() if no such element exists.
1306 */
1307 iterator
1308 lower_bound(const key_type& __x)
1309 { return _M_t.lower_bound(__x); }
1310
1311 #if __cplusplus > 201103L
1312 template<typename _Kt>
1313 auto
1314 lower_bound(const _Kt& __x)
1315 -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
1316 { return iterator(_M_t._M_lower_bound_tr(__x)); }
1317 #endif
1318 ///@}
1319
1320 ///@{
1321 /**
1322 * @brief Finds the beginning of a subsequence matching given key.
1323 * @param __x Key of (key, value) pair to be located.
1324 * @return Read-only (constant) iterator pointing to first element
1325 * equal to or greater than key, or end().
1326 *
1327 * This function returns the first element of a subsequence of elements
1328 * that matches the given key. If unsuccessful it returns an iterator
1329 * pointing to the first element that has a greater value than given key
1330 * or end() if no such element exists.
1331 */
1332 const_iterator
1333 lower_bound(const key_type& __x) const
1334 { return _M_t.lower_bound(__x); }
1335
1336 #if __cplusplus > 201103L
1337 template<typename _Kt>
1338 auto
1339 lower_bound(const _Kt& __x) const
1340 -> decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
1341 { return const_iterator(_M_t._M_lower_bound_tr(__x)); }
1342 #endif
1343 ///@}
1344
1345 ///@{
1346 /**
1347 * @brief Finds the end of a subsequence matching given key.
1348 * @param __x Key of (key, value) pair to be located.
1349 * @return Iterator pointing to the first element
1350 * greater than key, or end().
1351 */
1352 iterator
1353 upper_bound(const key_type& __x)
1354 { return _M_t.upper_bound(__x); }
1355
1356 #if __cplusplus > 201103L
1357 template<typename _Kt>
1358 auto
1359 upper_bound(const _Kt& __x)
1360 -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
1361 { return iterator(_M_t._M_upper_bound_tr(__x)); }
1362 #endif
1363 ///@}
1364
1365 ///@{
1366 /**
1367 * @brief Finds the end of a subsequence matching given key.
1368 * @param __x Key of (key, value) pair to be located.
1369 * @return Read-only (constant) iterator pointing to first iterator
1370 * greater than key, or end().
1371 */
1372 const_iterator
1373 upper_bound(const key_type& __x) const
1374 { return _M_t.upper_bound(__x); }
1375
1376 #if __cplusplus > 201103L
1377 template<typename _Kt>
1378 auto
1379 upper_bound(const _Kt& __x) const
1380 -> decltype(const_iterator(_M_t._M_upper_bound_tr(__x)))
1381 { return const_iterator(_M_t._M_upper_bound_tr(__x)); }
1382 #endif
1383 ///@}
1384
1385 ///@{
1386 /**
1387 * @brief Finds a subsequence matching given key.
1388 * @param __x Key of (key, value) pairs to be located.
1389 * @return Pair of iterators that possibly points to the subsequence
1390 * matching given key.
1391 *
1392 * This function is equivalent to
1393 * @code
1394 * std::make_pair(c.lower_bound(val),
1395 * c.upper_bound(val))
1396 * @endcode
1397 * (but is faster than making the calls separately).
1398 *
1399 * This function probably only makes sense for multimaps.
1400 */
1401 std::pair<iterator, iterator>
1402 equal_range(const key_type& __x)
1403 { return _M_t.equal_range(__x); }
1404
1405 #if __cplusplus > 201103L
1406 template<typename _Kt>
1407 auto
1408 equal_range(const _Kt& __x)
1409 -> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
1410 { return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
1411 #endif
1412 ///@}
1413
1414 ///@{
1415 /**
1416 * @brief Finds a subsequence matching given key.
1417 * @param __x Key of (key, value) pairs to be located.
1418 * @return Pair of read-only (constant) iterators that possibly points
1419 * to the subsequence matching given key.
1420 *
1421 * This function is equivalent to
1422 * @code
1423 * std::make_pair(c.lower_bound(val),
1424 * c.upper_bound(val))
1425 * @endcode
1426 * (but is faster than making the calls separately).
1427 *
1428 * This function probably only makes sense for multimaps.
1429 */
1430 std::pair<const_iterator, const_iterator>
1431 equal_range(const key_type& __x) const
1432 { return _M_t.equal_range(__x); }
1433
1434 #if __cplusplus > 201103L
1435 template<typename _Kt>
1436 auto
1437 equal_range(const _Kt& __x) const
1438 -> decltype(pair<const_iterator, const_iterator>(
1439 _M_t._M_equal_range_tr(__x)))
1440 {
1441 return pair<const_iterator, const_iterator>(
1442 _M_t._M_equal_range_tr(__x));
1443 }
1444 #endif
1445 ///@}
1446
1447 template<typename _K1, typename _T1, typename _C1, typename _A1>
1448 friend bool
1449 operator==(const map<_K1, _T1, _C1, _A1>&,
1450 const map<_K1, _T1, _C1, _A1>&);
1451
1452 #if __cpp_lib_three_way_comparison
1453 template<typename _K1, typename _T1, typename _C1, typename _A1>
1454 friend __detail::__synth3way_t<pair<const _K1, _T1>>
1455 operator<=>(const map<_K1, _T1, _C1, _A1>&,
1456 const map<_K1, _T1, _C1, _A1>&);
1457 #else
1458 template<typename _K1, typename _T1, typename _C1, typename _A1>
1459 friend bool
1460 operator<(const map<_K1, _T1, _C1, _A1>&,
1461 const map<_K1, _T1, _C1, _A1>&);
1462 #endif
1463 };
1464
1465
1466 #if __cpp_deduction_guides >= 201606
1467
1468 template<typename _InputIterator,
1469 typename _Compare = less<__iter_key_t<_InputIterator>>,
1470 typename _Allocator = allocator<__iter_to_alloc_t<_InputIterator>>,
1471 typename = _RequireInputIter<_InputIterator>,
1472 typename = _RequireNotAllocator<_Compare>,
1473 typename = _RequireAllocator<_Allocator>>
1474 map(_InputIterator, _InputIterator,
1475 _Compare = _Compare(), _Allocator = _Allocator())
1476 -> map<__iter_key_t<_InputIterator>, __iter_val_t<_InputIterator>,
1477 _Compare, _Allocator>;
1478
1479 template<typename _Key, typename _Tp, typename _Compare = less<_Key>,
1480 typename _Allocator = allocator<pair<const _Key, _Tp>>,
1481 typename = _RequireNotAllocator<_Compare>,
1482 typename = _RequireAllocator<_Allocator>>
1483 map(initializer_list<pair<_Key, _Tp>>,
1484 _Compare = _Compare(), _Allocator = _Allocator())
1485 -> map<_Key, _Tp, _Compare, _Allocator>;
1486
1487 template <typename _InputIterator, typename _Allocator,
1488 typename = _RequireInputIter<_InputIterator>,
1489 typename = _RequireAllocator<_Allocator>>
1490 map(_InputIterator, _InputIterator, _Allocator)
1491 -> map<__iter_key_t<_InputIterator>, __iter_val_t<_InputIterator>,
1492 less<__iter_key_t<_InputIterator>>, _Allocator>;
1493
1494 template<typename _Key, typename _Tp, typename _Allocator,
1495 typename = _RequireAllocator<_Allocator>>
1496 map(initializer_list<pair<_Key, _Tp>>, _Allocator)
1497 -> map<_Key, _Tp, less<_Key>, _Allocator>;
1498
1499 #endif // deduction guides
1500
1501 /**
1502 * @brief Map equality comparison.
1503 * @param __x A %map.
1504 * @param __y A %map of the same type as @a x.
1505 * @return True iff the size and elements of the maps are equal.
1506 *
1507 * This is an equivalence relation. It is linear in the size of the
1508 * maps. Maps are considered equivalent if their sizes are equal,
1509 * and if corresponding elements compare equal.
1510 */
1511 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1512 inline bool
1513 operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1514 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1515 { return __x._M_t == __y._M_t; }
1516
1517 #if __cpp_lib_three_way_comparison
1518 /**
1519 * @brief Map ordering relation.
1520 * @param __x A `map`.
1521 * @param __y A `map` of the same type as `x`.
1522 * @return A value indicating whether `__x` is less than, equal to,
1523 * greater than, or incomparable with `__y`.
1524 *
1525 * This is a total ordering relation. It is linear in the size of the
1526 * maps. The elements must be comparable with @c <.
1527 *
1528 * See `std::lexicographical_compare_three_way()` for how the determination
1529 * is made. This operator is used to synthesize relational operators like
1530 * `<` and `>=` etc.
1531 */
1532 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1533 inline __detail::__synth3way_t<pair<const _Key, _Tp>>
1534 operator<=>(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1535 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1536 { return __x._M_t <=> __y._M_t; }
1537 #else
1538 /**
1539 * @brief Map ordering relation.
1540 * @param __x A %map.
1541 * @param __y A %map of the same type as @a x.
1542 * @return True iff @a x is lexicographically less than @a y.
1543 *
1544 * This is a total ordering relation. It is linear in the size of the
1545 * maps. The elements must be comparable with @c <.
1546 *
1547 * See std::lexicographical_compare() for how the determination is made.
1548 */
1549 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1550 inline bool
1551 operator<(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1552 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1553 { return __x._M_t < __y._M_t; }
1554
1555 /// Based on operator==
1556 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1557 inline bool
1558 operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1559 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1560 { return !(__x == __y); }
1561
1562 /// Based on operator<
1563 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1564 inline bool
1565 operator>(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1566 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1567 { return __y < __x; }
1568
1569 /// Based on operator<
1570 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1571 inline bool
1572 operator<=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1573 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1574 { return !(__y < __x); }
1575
1576 /// Based on operator<
1577 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1578 inline bool
1579 operator>=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1580 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1581 { return !(__x < __y); }
1582 #endif // three-way comparison
1583
1584 /// See std::map::swap().
1585 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1586 inline void
1587 swap(map<_Key, _Tp, _Compare, _Alloc>& __x,
1588 map<_Key, _Tp, _Compare, _Alloc>& __y)
1589 _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
1590 { __x.swap(__y); }
1591
1592 _GLIBCXX_END_NAMESPACE_CONTAINER
1593
1594 #if __cplusplus > 201402L
1595 // Allow std::map access to internals of compatible maps.
1596 template<typename _Key, typename _Val, typename _Cmp1, typename _Alloc,
1597 typename _Cmp2>
1598 struct
1599 _Rb_tree_merge_helper<_GLIBCXX_STD_C::map<_Key, _Val, _Cmp1, _Alloc>,
1600 _Cmp2>
1601 {
1602 private:
1603 friend class _GLIBCXX_STD_C::map<_Key, _Val, _Cmp1, _Alloc>;
1604
1605 static auto&
1606 _S_get_tree(_GLIBCXX_STD_C::map<_Key, _Val, _Cmp2, _Alloc>& __map)
1607 { return __map._M_t; }
1608
1609 static auto&
1610 _S_get_tree(_GLIBCXX_STD_C::multimap<_Key, _Val, _Cmp2, _Alloc>& __map)
1611 { return __map._M_t; }
1612 };
1613 #endif // C++17
1614
1615 _GLIBCXX_END_NAMESPACE_VERSION
1616 } // namespace std
1617
1618 #endif /* _STL_MAP_H */
1619