1// Map implementation -*- C++ -*-
2
3// Copyright (C) 2001-2019 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
66namespace 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 *
80 * @tparam _Key Type of key objects.
81 * @tparam _Tp Type of mapped objects.
82 * @tparam _Compare Comparison function object type, defaults to less<_Key>.
83 * @tparam _Alloc Allocator type, defaults to
84 * allocator<pair<const _Key, _Tp>.
85 *
86 * Meets the requirements of a <a href="tables.html#65">container</a>, a
87 * <a href="tables.html#66">reversible container</a>, and an
88 * <a href="tables.html#69">associative container</a> (using unique keys).
89 * For a @c map<Key,T> the key_type is Key, the mapped_type is T, and the
90 * value_type is std::pair<const Key,T>.
91 *
92 * Maps support bidirectional iterators.
93 *
94 * The private tree data is declared exactly the same way for map and
95 * multimap; the distinction is made entirely in how the tree functions are
96 * called (*_unique versus *_equal, same as the standard).
97 */
98 template <typename _Key, typename _Tp, typename _Compare = std::less<_Key>,
99 typename _Alloc = std::allocator<std::pair<const _Key, _Tp> > >
100 class map
101 {
102 public:
103 typedef _Key key_type;
104 typedef _Tp mapped_type;
105 typedef std::pair<const _Key, _Tp> value_type;
106 typedef _Compare key_compare;
107 typedef _Alloc allocator_type;
108
109 private:
110#ifdef _GLIBCXX_CONCEPT_CHECKS
111 // concept requirements
112 typedef typename _Alloc::value_type _Alloc_value_type;
113# if __cplusplus < 201103L
114 __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
115# endif
116 __glibcxx_class_requires4(_Compare, bool, _Key, _Key,
117 _BinaryFunctionConcept)
118 __glibcxx_class_requires2(value_type, _Alloc_value_type, _SameTypeConcept)
119#endif
120
121#if __cplusplus >= 201103L && defined(__STRICT_ANSI__)
122 static_assert(is_same<typename _Alloc::value_type, value_type>::value,
123 "std::map must have the same value_type as its allocator");
124#endif
125
126 public:
127 class value_compare
128 : public std::binary_function<value_type, value_type, bool>
129 {
130 friend class map<_Key, _Tp, _Compare, _Alloc>;
131 protected:
132 _Compare comp;
133
134 value_compare(_Compare __c)
135 : comp(__c) { }
136
137 public:
138 bool operator()(const value_type& __x, const value_type& __y) const
139 { return comp(__x.first, __y.first); }
140 };
141
142 private:
143 /// This turns a red-black tree into a [multi]map.
144 typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
145 rebind<value_type>::other _Pair_alloc_type;
146
147 typedef _Rb_tree<key_type, value_type, _Select1st<value_type>,
148 key_compare, _Pair_alloc_type> _Rep_type;
149
150 /// The actual tree structure.
151 _Rep_type _M_t;
152
153 typedef __gnu_cxx::__alloc_traits<_Pair_alloc_type> _Alloc_traits;
154
155 public:
156 // many of these are specified differently in ISO, but the following are
157 // "functionally equivalent"
158 typedef typename _Alloc_traits::pointer pointer;
159 typedef typename _Alloc_traits::const_pointer const_pointer;
160 typedef typename _Alloc_traits::reference reference;
161 typedef typename _Alloc_traits::const_reference const_reference;
162 typedef typename _Rep_type::iterator iterator;
163 typedef typename _Rep_type::const_iterator const_iterator;
164 typedef typename _Rep_type::size_type size_type;
165 typedef typename _Rep_type::difference_type difference_type;
166 typedef typename _Rep_type::reverse_iterator reverse_iterator;
167 typedef typename _Rep_type::const_reverse_iterator const_reverse_iterator;
168
169#if __cplusplus > 201402L
170 using node_type = typename _Rep_type::node_type;
171 using insert_return_type = typename _Rep_type::insert_return_type;
172#endif
173
174 // [23.3.1.1] construct/copy/destroy
175 // (get_allocator() is also listed in this section)
176
177 /**
178 * @brief Default constructor creates no elements.
179 */
180#if __cplusplus < 201103L
181 map() : _M_t() { }
182#else
183 map() = default;
184#endif
185
186 /**
187 * @brief Creates a %map with no elements.
188 * @param __comp A comparison object.
189 * @param __a An allocator object.
190 */
191 explicit
192 map(const _Compare& __comp,
193 const allocator_type& __a = allocator_type())
194 : _M_t(__comp, _Pair_alloc_type(__a)) { }
195
196 /**
197 * @brief %Map copy constructor.
198 *
199 * Whether the allocator is copied depends on the allocator traits.
200 */
201#if __cplusplus < 201103L
202 map(const map& __x)
203 : _M_t(__x._M_t) { }
204#else
205 map(const map&) = default;
206
207 /**
208 * @brief %Map move constructor.
209 *
210 * The newly-created %map contains the exact contents of the moved
211 * instance. The moved instance is a valid, but unspecified, %map.
212 */
213 map(map&&) = default;
214
215 /**
216 * @brief Builds a %map from an initializer_list.
217 * @param __l An initializer_list.
218 * @param __comp A comparison object.
219 * @param __a An allocator object.
220 *
221 * Create a %map consisting of copies of the elements in the
222 * initializer_list @a __l.
223 * This is linear in N if the range is already sorted, and NlogN
224 * otherwise (where N is @a __l.size()).
225 */
226 map(initializer_list<value_type> __l,
227 const _Compare& __comp = _Compare(),
228 const allocator_type& __a = allocator_type())
229 : _M_t(__comp, _Pair_alloc_type(__a))
230 { _M_t._M_insert_range_unique(__l.begin(), __l.end()); }
231
232 /// Allocator-extended default constructor.
233 explicit
234 map(const allocator_type& __a)
235 : _M_t(_Pair_alloc_type(__a)) { }
236
237 /// Allocator-extended copy constructor.
238 map(const map& __m, const allocator_type& __a)
239 : _M_t(__m._M_t, _Pair_alloc_type(__a)) { }
240
241 /// Allocator-extended move constructor.
242 map(map&& __m, const allocator_type& __a)
243 noexcept(is_nothrow_copy_constructible<_Compare>::value
244 && _Alloc_traits::_S_always_equal())
245 : _M_t(std::move(__m._M_t), _Pair_alloc_type(__a)) { }
246
247 /// Allocator-extended initialier-list constructor.
248 map(initializer_list<value_type> __l, const allocator_type& __a)
249 : _M_t(_Pair_alloc_type(__a))
250 { _M_t._M_insert_range_unique(__l.begin(), __l.end()); }
251
252 /// Allocator-extended range constructor.
253 template<typename _InputIterator>
254 map(_InputIterator __first, _InputIterator __last,
255 const allocator_type& __a)
256 : _M_t(_Pair_alloc_type(__a))
257 { _M_t._M_insert_range_unique(__first, __last); }
258#endif
259
260 /**
261 * @brief Builds a %map from a range.
262 * @param __first An input iterator.
263 * @param __last An input iterator.
264 *
265 * Create a %map consisting of copies of the elements from
266 * [__first,__last). This is linear in N if the range is
267 * already sorted, and NlogN otherwise (where N is
268 * distance(__first,__last)).
269 */
270 template<typename _InputIterator>
271 map(_InputIterator __first, _InputIterator __last)
272 : _M_t()
273 { _M_t._M_insert_range_unique(__first, __last); }
274
275 /**
276 * @brief Builds a %map from a range.
277 * @param __first An input iterator.
278 * @param __last An input iterator.
279 * @param __comp A comparison functor.
280 * @param __a An allocator object.
281 *
282 * Create a %map consisting of copies of the elements from
283 * [__first,__last). This is linear in N if the range is
284 * already sorted, and NlogN otherwise (where N is
285 * distance(__first,__last)).
286 */
287 template<typename _InputIterator>
288 map(_InputIterator __first, _InputIterator __last,
289 const _Compare& __comp,
290 const allocator_type& __a = allocator_type())
291 : _M_t(__comp, _Pair_alloc_type(__a))
292 { _M_t._M_insert_range_unique(__first, __last); }
293
294#if __cplusplus >= 201103L
295 /**
296 * The dtor only erases the elements, and note that if the elements
297 * themselves are pointers, the pointed-to memory is not touched in any
298 * way. Managing the pointer is the user's responsibility.
299 */
300 ~map() = default;
301#endif
302
303 /**
304 * @brief %Map assignment operator.
305 *
306 * Whether the allocator is copied depends on the allocator traits.
307 */
308#if __cplusplus < 201103L
309 map&
310 operator=(const map& __x)
311 {
312 _M_t = __x._M_t;
313 return *this;
314 }
315#else
316 map&
317 operator=(const map&) = default;
318
319 /// Move assignment operator.
320 map&
321 operator=(map&&) = default;
322
323 /**
324 * @brief %Map list assignment operator.
325 * @param __l An initializer_list.
326 *
327 * This function fills a %map with copies of the elements in the
328 * initializer list @a __l.
329 *
330 * Note that the assignment completely changes the %map and
331 * that the resulting %map's size is the same as the number
332 * of elements assigned.
333 */
334 map&
335 operator=(initializer_list<value_type> __l)
336 {
337 _M_t._M_assign_unique(__l.begin(), __l.end());
338 return *this;
339 }
340#endif
341
342 /// Get a copy of the memory allocation object.
343 allocator_type
344 get_allocator() const _GLIBCXX_NOEXCEPT
345 { return allocator_type(_M_t.get_allocator()); }
346
347 // iterators
348 /**
349 * Returns a read/write iterator that points to the first pair in the
350 * %map.
351 * Iteration is done in ascending order according to the keys.
352 */
353 iterator
354 begin() _GLIBCXX_NOEXCEPT
355 { return _M_t.begin(); }
356
357 /**
358 * Returns a read-only (constant) iterator that points to the first pair
359 * in the %map. Iteration is done in ascending order according to the
360 * keys.
361 */
362 const_iterator
363 begin() const _GLIBCXX_NOEXCEPT
364 { return _M_t.begin(); }
365
366 /**
367 * Returns a read/write iterator that points one past the last
368 * pair in the %map. Iteration is done in ascending order
369 * according to the keys.
370 */
371 iterator
372 end() _GLIBCXX_NOEXCEPT
373 { return _M_t.end(); }
374
375 /**
376 * Returns a read-only (constant) iterator that points one past the last
377 * pair in the %map. Iteration is done in ascending order according to
378 * the keys.
379 */
380 const_iterator
381 end() const _GLIBCXX_NOEXCEPT
382 { return _M_t.end(); }
383
384 /**
385 * Returns a read/write reverse iterator that points to the last pair in
386 * the %map. Iteration is done in descending order according to the
387 * keys.
388 */
389 reverse_iterator
390 rbegin() _GLIBCXX_NOEXCEPT
391 { return _M_t.rbegin(); }
392
393 /**
394 * Returns a read-only (constant) reverse iterator that points to the
395 * last pair in the %map. Iteration is done in descending order
396 * according to the keys.
397 */
398 const_reverse_iterator
399 rbegin() const _GLIBCXX_NOEXCEPT
400 { return _M_t.rbegin(); }
401
402 /**
403 * Returns a read/write reverse iterator that points to one before the
404 * first pair in the %map. Iteration is done in descending order
405 * according to the keys.
406 */
407 reverse_iterator
408 rend() _GLIBCXX_NOEXCEPT
409 { return _M_t.rend(); }
410
411 /**
412 * Returns a read-only (constant) reverse iterator that points to one
413 * before the first pair in the %map. Iteration is done in descending
414 * order according to the keys.
415 */
416 const_reverse_iterator
417 rend() const _GLIBCXX_NOEXCEPT
418 { return _M_t.rend(); }
419
420#if __cplusplus >= 201103L
421 /**
422 * Returns a read-only (constant) iterator that points to the first pair
423 * in the %map. Iteration is done in ascending order according to the
424 * keys.
425 */
426 const_iterator
427 cbegin() const noexcept
428 { return _M_t.begin(); }
429
430 /**
431 * Returns a read-only (constant) iterator that points one past the last
432 * pair in the %map. Iteration is done in ascending order according to
433 * the keys.
434 */
435 const_iterator
436 cend() const noexcept
437 { return _M_t.end(); }
438
439 /**
440 * Returns a read-only (constant) reverse iterator that points to the
441 * last pair in the %map. Iteration is done in descending order
442 * according to the keys.
443 */
444 const_reverse_iterator
445 crbegin() const noexcept
446 { return _M_t.rbegin(); }
447
448 /**
449 * Returns a read-only (constant) reverse iterator that points to one
450 * before the first pair in the %map. Iteration is done in descending
451 * order according to the keys.
452 */
453 const_reverse_iterator
454 crend() const noexcept
455 { return _M_t.rend(); }
456#endif
457
458 // capacity
459 /** Returns true if the %map is empty. (Thus begin() would equal
460 * end().)
461 */
462 _GLIBCXX_NODISCARD bool
463 empty() const _GLIBCXX_NOEXCEPT
464 { return _M_t.empty(); }
465
466 /** Returns the size of the %map. */
467 size_type
468 size() const _GLIBCXX_NOEXCEPT
469 { return _M_t.size(); }
470
471 /** Returns the maximum size of the %map. */
472 size_type
473 max_size() const _GLIBCXX_NOEXCEPT
474 { return _M_t.max_size(); }
475
476 // [23.3.1.2] element access
477 /**
478 * @brief Subscript ( @c [] ) access to %map data.
479 * @param __k The key for which data should be retrieved.
480 * @return A reference to the data of the (key,data) %pair.
481 *
482 * Allows for easy lookup with the subscript ( @c [] )
483 * operator. Returns data associated with the key specified in
484 * subscript. If the key does not exist, a pair with that key
485 * is created using default values, which is then returned.
486 *
487 * Lookup requires logarithmic time.
488 */
489 mapped_type&
490 operator[](const key_type& __k)
491 {
492 // concept requirements
493 __glibcxx_function_requires(_DefaultConstructibleConcept<mapped_type>)
494
495 iterator __i = lower_bound(__k);
496 // __i->first is greater than or equivalent to __k.
497 if (__i == end() || key_comp()(__k, (*__i).first))
498#if __cplusplus >= 201103L
499 __i = _M_t._M_emplace_hint_unique(__i, std::piecewise_construct,
500 std::tuple<const key_type&>(__k),
501 std::tuple<>());
502#else
503 __i = insert(__i, value_type(__k, mapped_type()));
504#endif
505 return (*__i).second;
506 }
507
508#if __cplusplus >= 201103L
509 mapped_type&
510 operator[](key_type&& __k)
511 {
512 // concept requirements
513 __glibcxx_function_requires(_DefaultConstructibleConcept<mapped_type>)
514
515 iterator __i = lower_bound(__k);
516 // __i->first is greater than or equivalent to __k.
517 if (__i == end() || key_comp()(__k, (*__i).first))
518 __i = _M_t._M_emplace_hint_unique(__i, std::piecewise_construct,
519 std::forward_as_tuple(std::move(__k)),
520 std::tuple<>());
521 return (*__i).second;
522 }
523#endif
524
525 // _GLIBCXX_RESOLVE_LIB_DEFECTS
526 // DR 464. Suggestion for new member functions in standard containers.
527 /**
528 * @brief Access to %map data.
529 * @param __k The key for which data should be retrieved.
530 * @return A reference to the data whose key is equivalent to @a __k, if
531 * such a data is present in the %map.
532 * @throw std::out_of_range If no such data is present.
533 */
534 mapped_type&
535 at(const key_type& __k)
536 {
537 iterator __i = lower_bound(__k);
538 if (__i == end() || key_comp()(__k, (*__i).first))
539 __throw_out_of_range(__N("map::at"));
540 return (*__i).second;
541 }
542
543 const mapped_type&
544 at(const key_type& __k) const
545 {
546 const_iterator __i = lower_bound(__k);
547 if (__i == end() || key_comp()(__k, (*__i).first))
548 __throw_out_of_range(__N("map::at"));
549 return (*__i).second;
550 }
551
552 // modifiers
553#if __cplusplus >= 201103L
554 /**
555 * @brief Attempts to build and insert a std::pair into the %map.
556 *
557 * @param __args Arguments used to generate a new pair instance (see
558 * std::piecewise_contruct for passing arguments to each
559 * part of the pair constructor).
560 *
561 * @return A pair, of which the first element is an iterator that points
562 * to the possibly inserted pair, and the second is a bool that
563 * is true if the pair was actually inserted.
564 *
565 * This function attempts to build and insert a (key, value) %pair into
566 * the %map.
567 * A %map relies on unique keys and thus a %pair is only inserted if its
568 * first element (the key) is not already present in the %map.
569 *
570 * Insertion requires logarithmic time.
571 */
572 template<typename... _Args>
573 std::pair<iterator, bool>
574 emplace(_Args&&... __args)
575 { return _M_t._M_emplace_unique(std::forward<_Args>(__args)...); }
576
577 /**
578 * @brief Attempts to build and insert a std::pair into the %map.
579 *
580 * @param __pos An iterator that serves as a hint as to where the pair
581 * should be inserted.
582 * @param __args Arguments used to generate a new pair instance (see
583 * std::piecewise_contruct for passing arguments to each
584 * part of the pair constructor).
585 * @return An iterator that points to the element with key of the
586 * std::pair built from @a __args (may or may not be that
587 * std::pair).
588 *
589 * This function is not concerned about whether the insertion took place,
590 * and thus does not return a boolean like the single-argument emplace()
591 * does.
592 * Note that the first parameter is only a hint and can potentially
593 * improve the performance of the insertion process. A bad hint would
594 * cause no gains in efficiency.
595 *
596 * See
597 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
598 * for more on @a hinting.
599 *
600 * Insertion requires logarithmic time (if the hint is not taken).
601 */
602 template<typename... _Args>
603 iterator
604 emplace_hint(const_iterator __pos, _Args&&... __args)
605 {
606 return _M_t._M_emplace_hint_unique(__pos,
607 std::forward<_Args>(__args)...);
608 }
609#endif
610
611#if __cplusplus > 201402L
612 /// Extract a node.
613 node_type
614 extract(const_iterator __pos)
615 {
616 __glibcxx_assert(__pos != end());
617 return _M_t.extract(__pos);
618 }
619
620 /// Extract a node.
621 node_type
622 extract(const key_type& __x)
623 { return _M_t.extract(__x); }
624
625 /// Re-insert an extracted node.
626 insert_return_type
627 insert(node_type&& __nh)
628 { return _M_t._M_reinsert_node_unique(std::move(__nh)); }
629
630 /// Re-insert an extracted node.
631 iterator
632 insert(const_iterator __hint, node_type&& __nh)
633 { return _M_t._M_reinsert_node_hint_unique(__hint, std::move(__nh)); }
634
635 template<typename, typename>
636 friend class std::_Rb_tree_merge_helper;
637
638 template<typename _C2>
639 void
640 merge(map<_Key, _Tp, _C2, _Alloc>& __source)
641 {
642 using _Merge_helper = _Rb_tree_merge_helper<map, _C2>;
643 _M_t._M_merge_unique(_Merge_helper::_S_get_tree(__source));
644 }
645
646 template<typename _C2>
647 void
648 merge(map<_Key, _Tp, _C2, _Alloc>&& __source)
649 { merge(__source); }
650
651 template<typename _C2>
652 void
653 merge(multimap<_Key, _Tp, _C2, _Alloc>& __source)
654 {
655 using _Merge_helper = _Rb_tree_merge_helper<map, _C2>;
656 _M_t._M_merge_unique(_Merge_helper::_S_get_tree(__source));
657 }
658
659 template<typename _C2>
660 void
661 merge(multimap<_Key, _Tp, _C2, _Alloc>&& __source)
662 { merge(__source); }
663#endif // C++17
664
665#if __cplusplus > 201402L
666#define __cpp_lib_map_try_emplace 201411
667 /**
668 * @brief Attempts to build and insert a std::pair into the %map.
669 *
670 * @param __k Key to use for finding a possibly existing pair in
671 * the map.
672 * @param __args Arguments used to generate the .second for a new pair
673 * instance.
674 *
675 * @return A pair, of which the first element is an iterator that points
676 * to the possibly inserted pair, and the second is a bool that
677 * is true if the pair was actually inserted.
678 *
679 * This function attempts to build and insert a (key, value) %pair into
680 * the %map.
681 * A %map relies on unique keys and thus a %pair is only inserted if its
682 * first element (the key) is not already present in the %map.
683 * If a %pair is not inserted, this function has no effect.
684 *
685 * Insertion requires logarithmic time.
686 */
687 template <typename... _Args>
688 pair<iterator, bool>
689 try_emplace(const key_type& __k, _Args&&... __args)
690 {
691 iterator __i = lower_bound(__k);
692 if (__i == end() || key_comp()(__k, (*__i).first))
693 {
694 __i = emplace_hint(__i, std::piecewise_construct,
695 std::forward_as_tuple(__k),
696 std::forward_as_tuple(
697 std::forward<_Args>(__args)...));
698 return {__i, true};
699 }
700 return {__i, false};
701 }
702
703 // move-capable overload
704 template <typename... _Args>
705 pair<iterator, bool>
706 try_emplace(key_type&& __k, _Args&&... __args)
707 {
708 iterator __i = lower_bound(__k);
709 if (__i == end() || key_comp()(__k, (*__i).first))
710 {
711 __i = emplace_hint(__i, std::piecewise_construct,
712 std::forward_as_tuple(std::move(__k)),
713 std::forward_as_tuple(
714 std::forward<_Args>(__args)...));
715 return {__i, true};
716 }
717 return {__i, false};
718 }
719
720 /**
721 * @brief Attempts to build and insert a std::pair into the %map.
722 *
723 * @param __hint An iterator that serves as a hint as to where the
724 * pair should be inserted.
725 * @param __k Key to use for finding a possibly existing pair in
726 * the map.
727 * @param __args Arguments used to generate the .second for a new pair
728 * instance.
729 * @return An iterator that points to the element with key of the
730 * std::pair built from @a __args (may or may not be that
731 * std::pair).
732 *
733 * This function is not concerned about whether the insertion took place,
734 * and thus does not return a boolean like the single-argument
735 * try_emplace() does. However, if insertion did not take place,
736 * this function has no effect.
737 * Note that the first parameter is only a hint and can potentially
738 * improve the performance of the insertion process. A bad hint would
739 * cause no gains in efficiency.
740 *
741 * See
742 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
743 * for more on @a hinting.
744 *
745 * Insertion requires logarithmic time (if the hint is not taken).
746 */
747 template <typename... _Args>
748 iterator
749 try_emplace(const_iterator __hint, const key_type& __k,
750 _Args&&... __args)
751 {
752 iterator __i;
753 auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k);
754 if (__true_hint.second)
755 __i = emplace_hint(iterator(__true_hint.second),
756 std::piecewise_construct,
757 std::forward_as_tuple(__k),
758 std::forward_as_tuple(
759 std::forward<_Args>(__args)...));
760 else
761 __i = iterator(__true_hint.first);
762 return __i;
763 }
764
765 // move-capable overload
766 template <typename... _Args>
767 iterator
768 try_emplace(const_iterator __hint, key_type&& __k, _Args&&... __args)
769 {
770 iterator __i;
771 auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k);
772 if (__true_hint.second)
773 __i = emplace_hint(iterator(__true_hint.second),
774 std::piecewise_construct,
775 std::forward_as_tuple(std::move(__k)),
776 std::forward_as_tuple(
777 std::forward<_Args>(__args)...));
778 else
779 __i = iterator(__true_hint.first);
780 return __i;
781 }
782#endif
783
784 /**
785 * @brief Attempts to insert a std::pair into the %map.
786 * @param __x Pair to be inserted (see std::make_pair for easy
787 * creation of pairs).
788 *
789 * @return A pair, of which the first element is an iterator that
790 * points to the possibly inserted pair, and the second is
791 * a bool that is true if the pair was actually inserted.
792 *
793 * This function attempts to insert a (key, value) %pair into the %map.
794 * A %map relies on unique keys and thus a %pair is only inserted if its
795 * first element (the key) is not already present in the %map.
796 *
797 * Insertion requires logarithmic time.
798 * @{
799 */
800 std::pair<iterator, bool>
801 insert(const value_type& __x)
802 { return _M_t._M_insert_unique(__x); }
803
804#if __cplusplus >= 201103L
805 // _GLIBCXX_RESOLVE_LIB_DEFECTS
806 // 2354. Unnecessary copying when inserting into maps with braced-init
807 std::pair<iterator, bool>
808 insert(value_type&& __x)
809 { return _M_t._M_insert_unique(std::move(__x)); }
810
811 template<typename _Pair>
812 __enable_if_t<is_constructible<value_type, _Pair>::value,
813 pair<iterator, bool>>
814 insert(_Pair&& __x)
815 { return _M_t._M_emplace_unique(std::forward<_Pair>(__x)); }
816#endif
817 // @}
818
819#if __cplusplus >= 201103L
820 /**
821 * @brief Attempts to insert a list of std::pairs into the %map.
822 * @param __list A std::initializer_list<value_type> of pairs to be
823 * inserted.
824 *
825 * Complexity similar to that of the range constructor.
826 */
827 void
828 insert(std::initializer_list<value_type> __list)
829 { insert(__list.begin(), __list.end()); }
830#endif
831
832 /**
833 * @brief Attempts to insert a std::pair into the %map.
834 * @param __position An iterator that serves as a hint as to where the
835 * pair should be inserted.
836 * @param __x Pair to be inserted (see std::make_pair for easy creation
837 * of pairs).
838 * @return An iterator that points to the element with key of
839 * @a __x (may or may not be the %pair passed in).
840 *
841
842 * This function is not concerned about whether the insertion
843 * took place, and thus does not return a boolean like the
844 * single-argument insert() does. Note that the first
845 * parameter is only a hint and can potentially improve the
846 * performance of the insertion process. A bad hint would
847 * cause no gains in efficiency.
848 *
849 * See
850 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/associative.html#containers.associative.insert_hints
851 * for more on @a hinting.
852 *
853 * Insertion requires logarithmic time (if the hint is not taken).
854 * @{
855 */
856 iterator
857#if __cplusplus >= 201103L
858 insert(const_iterator __position, const value_type& __x)
859#else
860 insert(iterator __position, const value_type& __x)
861#endif
862 { return _M_t._M_insert_unique_(__position, __x); }
863
864#if __cplusplus >= 201103L
865 // _GLIBCXX_RESOLVE_LIB_DEFECTS
866 // 2354. Unnecessary copying when inserting into maps with braced-init
867 iterator
868 insert(const_iterator __position, value_type&& __x)
869 { return _M_t._M_insert_unique_(__position, std::move(__x)); }
870
871 template<typename _Pair>
872 __enable_if_t<is_constructible<value_type, _Pair>::value, iterator>
873 insert(const_iterator __position, _Pair&& __x)
874 {
875 return _M_t._M_emplace_hint_unique(__position,
876 std::forward<_Pair>(__x));
877 }
878#endif
879 // @}
880
881 /**
882 * @brief Template function that attempts to insert a range of elements.
883 * @param __first Iterator pointing to the start of the range to be
884 * inserted.
885 * @param __last Iterator pointing to the end of the range.
886 *
887 * Complexity similar to that of the range constructor.
888 */
889 template<typename _InputIterator>
890 void
891 insert(_InputIterator __first, _InputIterator __last)
892 { _M_t._M_insert_range_unique(__first, __last); }
893
894#if __cplusplus > 201402L
895#define __cpp_lib_map_insertion 201411
896 /**
897 * @brief Attempts to insert or assign a std::pair into the %map.
898 * @param __k Key to use for finding a possibly existing pair in
899 * the map.
900 * @param __obj Argument used to generate the .second for a pair
901 * instance.
902 *
903 * @return A pair, of which the first element is an iterator that
904 * points to the possibly inserted pair, and the second is
905 * a bool that is true if the pair was actually inserted.
906 *
907 * This function attempts to insert a (key, value) %pair into the %map.
908 * A %map relies on unique keys and thus a %pair is only inserted if its
909 * first element (the key) is not already present in the %map.
910 * If the %pair was already in the %map, the .second of the %pair
911 * is assigned from __obj.
912 *
913 * Insertion requires logarithmic time.
914 */
915 template <typename _Obj>
916 pair<iterator, bool>
917 insert_or_assign(const key_type& __k, _Obj&& __obj)
918 {
919 iterator __i = lower_bound(__k);
920 if (__i == end() || key_comp()(__k, (*__i).first))
921 {
922 __i = emplace_hint(__i, std::piecewise_construct,
923 std::forward_as_tuple(__k),
924 std::forward_as_tuple(
925 std::forward<_Obj>(__obj)));
926 return {__i, true};
927 }
928 (*__i).second = std::forward<_Obj>(__obj);
929 return {__i, false};
930 }
931
932 // move-capable overload
933 template <typename _Obj>
934 pair<iterator, bool>
935 insert_or_assign(key_type&& __k, _Obj&& __obj)
936 {
937 iterator __i = lower_bound(__k);
938 if (__i == end() || key_comp()(__k, (*__i).first))
939 {
940 __i = emplace_hint(__i, std::piecewise_construct,
941 std::forward_as_tuple(std::move(__k)),
942 std::forward_as_tuple(
943 std::forward<_Obj>(__obj)));
944 return {__i, true};
945 }
946 (*__i).second = std::forward<_Obj>(__obj);
947 return {__i, false};
948 }
949
950 /**
951 * @brief Attempts to insert or assign a std::pair into the %map.
952 * @param __hint An iterator that serves as a hint as to where the
953 * pair should be inserted.
954 * @param __k Key to use for finding a possibly existing pair in
955 * the map.
956 * @param __obj Argument used to generate the .second for a pair
957 * instance.
958 *
959 * @return An iterator that points to the element with key of
960 * @a __x (may or may not be the %pair passed in).
961 *
962 * This function attempts to insert a (key, value) %pair into the %map.
963 * A %map relies on unique keys and thus a %pair is only inserted if its
964 * first element (the key) is not already present in the %map.
965 * If the %pair was already in the %map, the .second of the %pair
966 * is assigned from __obj.
967 *
968 * Insertion requires logarithmic time.
969 */
970 template <typename _Obj>
971 iterator
972 insert_or_assign(const_iterator __hint,
973 const key_type& __k, _Obj&& __obj)
974 {
975 iterator __i;
976 auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k);
977 if (__true_hint.second)
978 {
979 return emplace_hint(iterator(__true_hint.second),
980 std::piecewise_construct,
981 std::forward_as_tuple(__k),
982 std::forward_as_tuple(
983 std::forward<_Obj>(__obj)));
984 }
985 __i = iterator(__true_hint.first);
986 (*__i).second = std::forward<_Obj>(__obj);
987 return __i;
988 }
989
990 // move-capable overload
991 template <typename _Obj>
992 iterator
993 insert_or_assign(const_iterator __hint, key_type&& __k, _Obj&& __obj)
994 {
995 iterator __i;
996 auto __true_hint = _M_t._M_get_insert_hint_unique_pos(__hint, __k);
997 if (__true_hint.second)
998 {
999 return emplace_hint(iterator(__true_hint.second),
1000 std::piecewise_construct,
1001 std::forward_as_tuple(std::move(__k)),
1002 std::forward_as_tuple(
1003 std::forward<_Obj>(__obj)));
1004 }
1005 __i = iterator(__true_hint.first);
1006 (*__i).second = std::forward<_Obj>(__obj);
1007 return __i;
1008 }
1009#endif
1010
1011#if __cplusplus >= 201103L
1012 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1013 // DR 130. Associative erase should return an iterator.
1014 /**
1015 * @brief Erases an element from a %map.
1016 * @param __position An iterator pointing to the element to be erased.
1017 * @return An iterator pointing to the element immediately following
1018 * @a position prior to the element being erased. If no such
1019 * element exists, end() is returned.
1020 *
1021 * This function erases an element, pointed to by the given
1022 * iterator, from a %map. Note that this function only erases
1023 * the element, and that if the element is itself a pointer,
1024 * the pointed-to memory is not touched in any way. Managing
1025 * the pointer is the user's responsibility.
1026 *
1027 * @{
1028 */
1029 iterator
1030 erase(const_iterator __position)
1031 { return _M_t.erase(__position); }
1032
1033 // LWG 2059
1034 _GLIBCXX_ABI_TAG_CXX11
1035 iterator
1036 erase(iterator __position)
1037 { return _M_t.erase(__position); }
1038 // @}
1039#else
1040 /**
1041 * @brief Erases an element from a %map.
1042 * @param __position An iterator pointing to the element to be erased.
1043 *
1044 * This function erases an element, pointed to by the given
1045 * iterator, from a %map. Note that this function only erases
1046 * the element, and that if the element is itself a pointer,
1047 * the pointed-to memory is not touched in any way. Managing
1048 * the pointer is the user's responsibility.
1049 */
1050 void
1051 erase(iterator __position)
1052 { _M_t.erase(__position); }
1053#endif
1054
1055 /**
1056 * @brief Erases elements according to the provided key.
1057 * @param __x Key of element to be erased.
1058 * @return The number of elements erased.
1059 *
1060 * This function erases all the elements located by the given key from
1061 * a %map.
1062 * Note that this function only erases the element, and that if
1063 * the element is itself a pointer, the pointed-to memory is not touched
1064 * in any way. Managing the pointer is the user's responsibility.
1065 */
1066 size_type
1067 erase(const key_type& __x)
1068 { return _M_t.erase(__x); }
1069
1070#if __cplusplus >= 201103L
1071 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1072 // DR 130. Associative erase should return an iterator.
1073 /**
1074 * @brief Erases a [first,last) range of elements from a %map.
1075 * @param __first Iterator pointing to the start of the range to be
1076 * erased.
1077 * @param __last Iterator pointing to the end of the range to
1078 * be erased.
1079 * @return The iterator @a __last.
1080 *
1081 * This function erases a sequence of elements from a %map.
1082 * Note that this function only erases the element, and that if
1083 * the element is itself a pointer, the pointed-to memory is not touched
1084 * in any way. Managing the pointer is the user's responsibility.
1085 */
1086 iterator
1087 erase(const_iterator __first, const_iterator __last)
1088 { return _M_t.erase(__first, __last); }
1089#else
1090 /**
1091 * @brief Erases a [__first,__last) range of elements from a %map.
1092 * @param __first Iterator pointing to the start of the range to be
1093 * erased.
1094 * @param __last Iterator pointing to the end of the range to
1095 * be erased.
1096 *
1097 * This function erases a sequence of elements from a %map.
1098 * Note that this function only erases the element, and that if
1099 * the element is itself a pointer, the pointed-to memory is not touched
1100 * in any way. Managing the pointer is the user's responsibility.
1101 */
1102 void
1103 erase(iterator __first, iterator __last)
1104 { _M_t.erase(__first, __last); }
1105#endif
1106
1107 /**
1108 * @brief Swaps data with another %map.
1109 * @param __x A %map of the same element and allocator types.
1110 *
1111 * This exchanges the elements between two maps in constant
1112 * time. (It is only swapping a pointer, an integer, and an
1113 * instance of the @c Compare type (which itself is often
1114 * stateless and empty), so it should be quite fast.) Note
1115 * that the global std::swap() function is specialized such
1116 * that std::swap(m1,m2) will feed to this function.
1117 *
1118 * Whether the allocators are swapped depends on the allocator traits.
1119 */
1120 void
1121 swap(map& __x)
1122 _GLIBCXX_NOEXCEPT_IF(__is_nothrow_swappable<_Compare>::value)
1123 { _M_t.swap(__x._M_t); }
1124
1125 /**
1126 * Erases all elements in a %map. Note that this function only
1127 * erases the elements, and that if the elements themselves are
1128 * pointers, the pointed-to memory is not touched in any way.
1129 * Managing the pointer is the user's responsibility.
1130 */
1131 void
1132 clear() _GLIBCXX_NOEXCEPT
1133 { _M_t.clear(); }
1134
1135 // observers
1136 /**
1137 * Returns the key comparison object out of which the %map was
1138 * constructed.
1139 */
1140 key_compare
1141 key_comp() const
1142 { return _M_t.key_comp(); }
1143
1144 /**
1145 * Returns a value comparison object, built from the key comparison
1146 * object out of which the %map was constructed.
1147 */
1148 value_compare
1149 value_comp() const
1150 { return value_compare(_M_t.key_comp()); }
1151
1152 // [23.3.1.3] map operations
1153
1154 //@{
1155 /**
1156 * @brief Tries to locate an element in a %map.
1157 * @param __x Key of (key, value) %pair to be located.
1158 * @return Iterator pointing to sought-after element, or end() if not
1159 * found.
1160 *
1161 * This function takes a key and tries to locate the element with which
1162 * the key matches. If successful the function returns an iterator
1163 * pointing to the sought after %pair. If unsuccessful it returns the
1164 * past-the-end ( @c end() ) iterator.
1165 */
1166
1167 iterator
1168 find(const key_type& __x)
1169 { return _M_t.find(__x); }
1170
1171#if __cplusplus > 201103L
1172 template<typename _Kt>
1173 auto
1174 find(const _Kt& __x) -> decltype(_M_t._M_find_tr(__x))
1175 { return _M_t._M_find_tr(__x); }
1176#endif
1177 //@}
1178
1179 //@{
1180 /**
1181 * @brief Tries to locate an element in a %map.
1182 * @param __x Key of (key, value) %pair to be located.
1183 * @return Read-only (constant) iterator pointing to sought-after
1184 * element, or end() if not found.
1185 *
1186 * This function takes a key and tries to locate the element with which
1187 * the key matches. If successful the function returns a constant
1188 * iterator pointing to the sought after %pair. If unsuccessful it
1189 * returns the past-the-end ( @c end() ) iterator.
1190 */
1191
1192 const_iterator
1193 find(const key_type& __x) const
1194 { return _M_t.find(__x); }
1195
1196#if __cplusplus > 201103L
1197 template<typename _Kt>
1198 auto
1199 find(const _Kt& __x) const -> decltype(_M_t._M_find_tr(__x))
1200 { return _M_t._M_find_tr(__x); }
1201#endif
1202 //@}
1203
1204 //@{
1205 /**
1206 * @brief Finds the number of elements with given key.
1207 * @param __x Key of (key, value) pairs to be located.
1208 * @return Number of elements with specified key.
1209 *
1210 * This function only makes sense for multimaps; for map the result will
1211 * either be 0 (not present) or 1 (present).
1212 */
1213 size_type
1214 count(const key_type& __x) const
1215 { return _M_t.find(__x) == _M_t.end() ? 0 : 1; }
1216
1217#if __cplusplus > 201103L
1218 template<typename _Kt>
1219 auto
1220 count(const _Kt& __x) const -> decltype(_M_t._M_count_tr(__x))
1221 { return _M_t._M_count_tr(__x); }
1222#endif
1223 //@}
1224
1225#if __cplusplus > 201703L
1226 //@{
1227 /**
1228 * @brief Finds whether an element with the given key exists.
1229 * @param __x Key of (key, value) pairs to be located.
1230 * @return True if there is an element with the specified key.
1231 */
1232 bool
1233 contains(const key_type& __x) const
1234 { return _M_t.find(__x) != _M_t.end(); }
1235
1236 template<typename _Kt>
1237 auto
1238 contains(const _Kt& __x) const
1239 -> decltype(_M_t._M_find_tr(__x), void(), true)
1240 { return _M_t._M_find_tr(__x) != _M_t.end(); }
1241 //@}
1242#endif
1243
1244 //@{
1245 /**
1246 * @brief Finds the beginning of a subsequence matching given key.
1247 * @param __x Key of (key, value) pair to be located.
1248 * @return Iterator pointing to first element equal to or greater
1249 * than key, or end().
1250 *
1251 * This function returns the first element of a subsequence of elements
1252 * that matches the given key. If unsuccessful it returns an iterator
1253 * pointing to the first element that has a greater value than given key
1254 * or end() if no such element exists.
1255 */
1256 iterator
1257 lower_bound(const key_type& __x)
1258 { return _M_t.lower_bound(__x); }
1259
1260#if __cplusplus > 201103L
1261 template<typename _Kt>
1262 auto
1263 lower_bound(const _Kt& __x)
1264 -> decltype(iterator(_M_t._M_lower_bound_tr(__x)))
1265 { return iterator(_M_t._M_lower_bound_tr(__x)); }
1266#endif
1267 //@}
1268
1269 //@{
1270 /**
1271 * @brief Finds the beginning of a subsequence matching given key.
1272 * @param __x Key of (key, value) pair to be located.
1273 * @return Read-only (constant) iterator pointing to first element
1274 * equal to or greater than key, or end().
1275 *
1276 * This function returns the first element of a subsequence of elements
1277 * that matches the given key. If unsuccessful it returns an iterator
1278 * pointing to the first element that has a greater value than given key
1279 * or end() if no such element exists.
1280 */
1281 const_iterator
1282 lower_bound(const key_type& __x) const
1283 { return _M_t.lower_bound(__x); }
1284
1285#if __cplusplus > 201103L
1286 template<typename _Kt>
1287 auto
1288 lower_bound(const _Kt& __x) const
1289 -> decltype(const_iterator(_M_t._M_lower_bound_tr(__x)))
1290 { return const_iterator(_M_t._M_lower_bound_tr(__x)); }
1291#endif
1292 //@}
1293
1294 //@{
1295 /**
1296 * @brief Finds the end of a subsequence matching given key.
1297 * @param __x Key of (key, value) pair to be located.
1298 * @return Iterator pointing to the first element
1299 * greater than key, or end().
1300 */
1301 iterator
1302 upper_bound(const key_type& __x)
1303 { return _M_t.upper_bound(__x); }
1304
1305#if __cplusplus > 201103L
1306 template<typename _Kt>
1307 auto
1308 upper_bound(const _Kt& __x)
1309 -> decltype(iterator(_M_t._M_upper_bound_tr(__x)))
1310 { return iterator(_M_t._M_upper_bound_tr(__x)); }
1311#endif
1312 //@}
1313
1314 //@{
1315 /**
1316 * @brief Finds the end of a subsequence matching given key.
1317 * @param __x Key of (key, value) pair to be located.
1318 * @return Read-only (constant) iterator pointing to first iterator
1319 * greater than key, or end().
1320 */
1321 const_iterator
1322 upper_bound(const key_type& __x) const
1323 { return _M_t.upper_bound(__x); }
1324
1325#if __cplusplus > 201103L
1326 template<typename _Kt>
1327 auto
1328 upper_bound(const _Kt& __x) const
1329 -> decltype(const_iterator(_M_t._M_upper_bound_tr(__x)))
1330 { return const_iterator(_M_t._M_upper_bound_tr(__x)); }
1331#endif
1332 //@}
1333
1334 //@{
1335 /**
1336 * @brief Finds a subsequence matching given key.
1337 * @param __x Key of (key, value) pairs to be located.
1338 * @return Pair of iterators that possibly points to the subsequence
1339 * matching given key.
1340 *
1341 * This function is equivalent to
1342 * @code
1343 * std::make_pair(c.lower_bound(val),
1344 * c.upper_bound(val))
1345 * @endcode
1346 * (but is faster than making the calls separately).
1347 *
1348 * This function probably only makes sense for multimaps.
1349 */
1350 std::pair<iterator, iterator>
1351 equal_range(const key_type& __x)
1352 { return _M_t.equal_range(__x); }
1353
1354#if __cplusplus > 201103L
1355 template<typename _Kt>
1356 auto
1357 equal_range(const _Kt& __x)
1358 -> decltype(pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)))
1359 { return pair<iterator, iterator>(_M_t._M_equal_range_tr(__x)); }
1360#endif
1361 //@}
1362
1363 //@{
1364 /**
1365 * @brief Finds a subsequence matching given key.
1366 * @param __x Key of (key, value) pairs to be located.
1367 * @return Pair of read-only (constant) iterators that possibly points
1368 * to the subsequence matching given key.
1369 *
1370 * This function is equivalent to
1371 * @code
1372 * std::make_pair(c.lower_bound(val),
1373 * c.upper_bound(val))
1374 * @endcode
1375 * (but is faster than making the calls separately).
1376 *
1377 * This function probably only makes sense for multimaps.
1378 */
1379 std::pair<const_iterator, const_iterator>
1380 equal_range(const key_type& __x) const
1381 { return _M_t.equal_range(__x); }
1382
1383#if __cplusplus > 201103L
1384 template<typename _Kt>
1385 auto
1386 equal_range(const _Kt& __x) const
1387 -> decltype(pair<const_iterator, const_iterator>(
1388 _M_t._M_equal_range_tr(__x)))
1389 {
1390 return pair<const_iterator, const_iterator>(
1391 _M_t._M_equal_range_tr(__x));
1392 }
1393#endif
1394 //@}
1395
1396 template<typename _K1, typename _T1, typename _C1, typename _A1>
1397 friend bool
1398 operator==(const map<_K1, _T1, _C1, _A1>&,
1399 const map<_K1, _T1, _C1, _A1>&);
1400
1401 template<typename _K1, typename _T1, typename _C1, typename _A1>
1402 friend bool
1403 operator<(const map<_K1, _T1, _C1, _A1>&,
1404 const map<_K1, _T1, _C1, _A1>&);
1405 };
1406
1407
1408#if __cpp_deduction_guides >= 201606
1409
1410 template<typename _InputIterator,
1411 typename _Compare = less<__iter_key_t<_InputIterator>>,
1412 typename _Allocator = allocator<__iter_to_alloc_t<_InputIterator>>,
1413 typename = _RequireInputIter<_InputIterator>,
1414 typename = _RequireNotAllocator<_Compare>,
1415 typename = _RequireAllocator<_Allocator>>
1416 map(_InputIterator, _InputIterator,
1417 _Compare = _Compare(), _Allocator = _Allocator())
1418 -> map<__iter_key_t<_InputIterator>, __iter_val_t<_InputIterator>,
1419 _Compare, _Allocator>;
1420
1421 template<typename _Key, typename _Tp, typename _Compare = less<_Key>,
1422 typename _Allocator = allocator<pair<const _Key, _Tp>>,
1423 typename = _RequireNotAllocator<_Compare>,
1424 typename = _RequireAllocator<_Allocator>>
1425 map(initializer_list<pair<_Key, _Tp>>,
1426 _Compare = _Compare(), _Allocator = _Allocator())
1427 -> map<_Key, _Tp, _Compare, _Allocator>;
1428
1429 template <typename _InputIterator, typename _Allocator,
1430 typename = _RequireInputIter<_InputIterator>,
1431 typename = _RequireAllocator<_Allocator>>
1432 map(_InputIterator, _InputIterator, _Allocator)
1433 -> map<__iter_key_t<_InputIterator>, __iter_val_t<_InputIterator>,
1434 less<__iter_key_t<_InputIterator>>, _Allocator>;
1435
1436 template<typename _Key, typename _Tp, typename _Allocator,
1437 typename = _RequireAllocator<_Allocator>>
1438 map(initializer_list<pair<_Key, _Tp>>, _Allocator)
1439 -> map<_Key, _Tp, less<_Key>, _Allocator>;
1440
1441#endif
1442
1443 /**
1444 * @brief Map equality comparison.
1445 * @param __x A %map.
1446 * @param __y A %map of the same type as @a x.
1447 * @return True iff the size and elements of the maps are equal.
1448 *
1449 * This is an equivalence relation. It is linear in the size of the
1450 * maps. Maps are considered equivalent if their sizes are equal,
1451 * and if corresponding elements compare equal.
1452 */
1453 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1454 inline bool
1455 operator==(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1456 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1457 { return __x._M_t == __y._M_t; }
1458
1459 /**
1460 * @brief Map ordering relation.
1461 * @param __x A %map.
1462 * @param __y A %map of the same type as @a x.
1463 * @return True iff @a x is lexicographically less than @a y.
1464 *
1465 * This is a total ordering relation. It is linear in the size of the
1466 * maps. The elements must be comparable with @c <.
1467 *
1468 * See std::lexicographical_compare() for how the determination is made.
1469 */
1470 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1471 inline bool
1472 operator<(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1473 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1474 { return __x._M_t < __y._M_t; }
1475
1476 /// Based on operator==
1477 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1478 inline bool
1479 operator!=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1480 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1481 { return !(__x == __y); }
1482
1483 /// Based on operator<
1484 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1485 inline bool
1486 operator>(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1487 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1488 { return __y < __x; }
1489
1490 /// Based on operator<
1491 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1492 inline bool
1493 operator<=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1494 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1495 { return !(__y < __x); }
1496
1497 /// Based on operator<
1498 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1499 inline bool
1500 operator>=(const map<_Key, _Tp, _Compare, _Alloc>& __x,
1501 const map<_Key, _Tp, _Compare, _Alloc>& __y)
1502 { return !(__x < __y); }
1503
1504 /// See std::map::swap().
1505 template<typename _Key, typename _Tp, typename _Compare, typename _Alloc>
1506 inline void
1507 swap(map<_Key, _Tp, _Compare, _Alloc>& __x,
1508 map<_Key, _Tp, _Compare, _Alloc>& __y)
1509 _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
1510 { __x.swap(__y); }
1511
1512_GLIBCXX_END_NAMESPACE_CONTAINER
1513
1514#if __cplusplus > 201402L
1515 // Allow std::map access to internals of compatible maps.
1516 template<typename _Key, typename _Val, typename _Cmp1, typename _Alloc,
1517 typename _Cmp2>
1518 struct
1519 _Rb_tree_merge_helper<_GLIBCXX_STD_C::map<_Key, _Val, _Cmp1, _Alloc>,
1520 _Cmp2>
1521 {
1522 private:
1523 friend class _GLIBCXX_STD_C::map<_Key, _Val, _Cmp1, _Alloc>;
1524
1525 static auto&
1526 _S_get_tree(_GLIBCXX_STD_C::map<_Key, _Val, _Cmp2, _Alloc>& __map)
1527 { return __map._M_t; }
1528
1529 static auto&
1530 _S_get_tree(_GLIBCXX_STD_C::multimap<_Key, _Val, _Cmp2, _Alloc>& __map)
1531 { return __map._M_t; }
1532 };
1533#endif // C++17
1534
1535_GLIBCXX_END_NAMESPACE_VERSION
1536} // namespace std
1537
1538#endif /* _STL_MAP_H */
1539