xref: /freebsd/contrib/llvm-project/libcxx/include/set (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_SET
11#define _LIBCPP_SET
12
13/*
14
15    set synopsis
16
17namespace std
18{
19
20template <class Key, class Compare = less<Key>,
21          class Allocator = allocator<Key>>
22class set
23{
24public:
25    // types:
26    typedef Key                                      key_type;
27    typedef key_type                                 value_type;
28    typedef Compare                                  key_compare;
29    typedef key_compare                              value_compare;
30    typedef Allocator                                allocator_type;
31    typedef typename allocator_type::reference       reference;
32    typedef typename allocator_type::const_reference const_reference;
33    typedef typename allocator_type::size_type       size_type;
34    typedef typename allocator_type::difference_type difference_type;
35    typedef typename allocator_type::pointer         pointer;
36    typedef typename allocator_type::const_pointer   const_pointer;
37
38    typedef implementation-defined                   iterator;
39    typedef implementation-defined                   const_iterator;
40    typedef std::reverse_iterator<iterator>          reverse_iterator;
41    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;
42    typedef unspecified                              node_type;               // C++17
43    typedef INSERT_RETURN_TYPE<iterator, node_type>  insert_return_type;      // C++17
44
45    // construct/copy/destroy:
46    set()
47        noexcept(
48            is_nothrow_default_constructible<allocator_type>::value &&
49            is_nothrow_default_constructible<key_compare>::value &&
50            is_nothrow_copy_constructible<key_compare>::value);
51    explicit set(const value_compare& comp);
52    set(const value_compare& comp, const allocator_type& a);
53    template <class InputIterator>
54        set(InputIterator first, InputIterator last,
55            const value_compare& comp = value_compare());
56    template <class InputIterator>
57        set(InputIterator first, InputIterator last, const value_compare& comp,
58            const allocator_type& a);
59    template<container-compatible-range<value_type> R>
60      set(from_range_t, R&& rg, const Compare& comp = Compare(), const Allocator& = Allocator()); // C++23
61    set(const set& s);
62    set(set&& s)
63        noexcept(
64            is_nothrow_move_constructible<allocator_type>::value &&
65            is_nothrow_move_constructible<key_compare>::value);
66    explicit set(const allocator_type& a);
67    set(const set& s, const allocator_type& a);
68    set(set&& s, const allocator_type& a);
69    set(initializer_list<value_type> il, const value_compare& comp = value_compare());
70    set(initializer_list<value_type> il, const value_compare& comp,
71        const allocator_type& a);
72    template <class InputIterator>
73        set(InputIterator first, InputIterator last, const allocator_type& a)
74            : set(first, last, Compare(), a) {}  // C++14
75    template<container-compatible-range<value_type> R>
76      set(from_range_t, R&& rg, const Allocator& a))
77        : set(from_range, std::forward<R>(rg), Compare(), a) { } // C++23
78    set(initializer_list<value_type> il, const allocator_type& a)
79        : set(il, Compare(), a) {}  // C++14
80    ~set();
81
82    set& operator=(const set& s);
83    set& operator=(set&& s)
84        noexcept(
85            allocator_type::propagate_on_container_move_assignment::value &&
86            is_nothrow_move_assignable<allocator_type>::value &&
87            is_nothrow_move_assignable<key_compare>::value);
88    set& operator=(initializer_list<value_type> il);
89
90    // iterators:
91          iterator begin() noexcept;
92    const_iterator begin() const noexcept;
93          iterator end() noexcept;
94    const_iterator end()   const noexcept;
95
96          reverse_iterator rbegin() noexcept;
97    const_reverse_iterator rbegin() const noexcept;
98          reverse_iterator rend() noexcept;
99    const_reverse_iterator rend()   const noexcept;
100
101    const_iterator         cbegin()  const noexcept;
102    const_iterator         cend()    const noexcept;
103    const_reverse_iterator crbegin() const noexcept;
104    const_reverse_iterator crend()   const noexcept;
105
106    // capacity:
107    bool      empty()    const noexcept;
108    size_type size()     const noexcept;
109    size_type max_size() const noexcept;
110
111    // modifiers:
112    template <class... Args>
113        pair<iterator, bool> emplace(Args&&... args);
114    template <class... Args>
115        iterator emplace_hint(const_iterator position, Args&&... args);
116    pair<iterator,bool> insert(const value_type& v);
117    pair<iterator,bool> insert(value_type&& v);
118    iterator insert(const_iterator position, const value_type& v);
119    iterator insert(const_iterator position, value_type&& v);
120    template <class InputIterator>
121        void insert(InputIterator first, InputIterator last);
122    template<container-compatible-range<value_type> R>
123      void insert_range(R&& rg);                                                      // C++23
124    void insert(initializer_list<value_type> il);
125
126    node_type extract(const_iterator position);                                       // C++17
127    node_type extract(const key_type& x);                                             // C++17
128    insert_return_type insert(node_type&& nh);                                        // C++17
129    iterator insert(const_iterator hint, node_type&& nh);                             // C++17
130
131    iterator  erase(const_iterator position);
132    iterator  erase(iterator position);  // C++14
133    size_type erase(const key_type& k);
134    iterator  erase(const_iterator first, const_iterator last);
135    void clear() noexcept;
136
137    template<class C2>
138      void merge(set<Key, C2, Allocator>& source);         // C++17
139    template<class C2>
140      void merge(set<Key, C2, Allocator>&& source);        // C++17
141    template<class C2>
142      void merge(multiset<Key, C2, Allocator>& source);    // C++17
143    template<class C2>
144      void merge(multiset<Key, C2, Allocator>&& source);   // C++17
145
146    void swap(set& s)
147        noexcept(
148            __is_nothrow_swappable<key_compare>::value &&
149            (!allocator_type::propagate_on_container_swap::value ||
150             __is_nothrow_swappable<allocator_type>::value));
151
152    // observers:
153    allocator_type get_allocator() const noexcept;
154    key_compare    key_comp()      const;
155    value_compare  value_comp()    const;
156
157    // set operations:
158          iterator find(const key_type& k);
159    const_iterator find(const key_type& k) const;
160    template<typename K>
161        iterator find(const K& x);
162    template<typename K>
163        const_iterator find(const K& x) const;  // C++14
164
165    template<typename K>
166        size_type count(const K& x) const;        // C++14
167    size_type      count(const key_type& k) const;
168
169    bool           contains(const key_type& x) const;  // C++20
170    template<class K> bool contains(const K& x) const; // C++20
171
172          iterator lower_bound(const key_type& k);
173    const_iterator lower_bound(const key_type& k) const;
174    template<typename K>
175        iterator lower_bound(const K& x);              // C++14
176    template<typename K>
177        const_iterator lower_bound(const K& x) const;  // C++14
178
179          iterator upper_bound(const key_type& k);
180    const_iterator upper_bound(const key_type& k) const;
181    template<typename K>
182        iterator upper_bound(const K& x);              // C++14
183    template<typename K>
184        const_iterator upper_bound(const K& x) const;  // C++14
185    pair<iterator,iterator>             equal_range(const key_type& k);
186    pair<const_iterator,const_iterator> equal_range(const key_type& k) const;
187    template<typename K>
188        pair<iterator,iterator>             equal_range(const K& x);        // C++14
189    template<typename K>
190        pair<const_iterator,const_iterator> equal_range(const K& x) const;  // C++14
191};
192
193template <class InputIterator,
194      class Compare = less<typename iterator_traits<InputIterator>::value_type>,
195      class Allocator = allocator<typename iterator_traits<InputIterator>::value_type>>
196set(InputIterator, InputIterator,
197    Compare = Compare(), Allocator = Allocator())
198  -> set<typename iterator_traits<InputIterator>::value_type, Compare, Allocator>; // C++17
199
200template<ranges::input_range R, class Compare = less<ranges::range_value_t<R>>,
201         class Allocator = allocator<ranges::range_value_t<R>>>
202  set(from_range_t, R&&, Compare = Compare(), Allocator = Allocator())
203    -> set<ranges::range_value_t<R>, Compare, Allocator>; // C++23
204
205template<class Key, class Compare = less<Key>, class Allocator = allocator<Key>>
206set(initializer_list<Key>, Compare = Compare(), Allocator = Allocator())
207  -> set<Key, Compare, Allocator>; // C++17
208
209template<class InputIterator, class Allocator>
210set(InputIterator, InputIterator, Allocator)
211  -> set<typename iterator_traits<InputIterator>::value_type,
212          less<typename iterator_traits<InputIterator>::value_type>, Allocator>; // C++17
213
214template<ranges::input_range R, class Allocator>
215  set(from_range_t, R&&, Allocator)
216    -> set<ranges::range_value_t<R>, less<ranges::range_value_t<R>>, Allocator>; // C++23
217
218template<class Key, class Allocator>
219set(initializer_list<Key>, Allocator) -> set<Key, less<Key>, Allocator>; // C++17
220
221template <class Key, class Compare, class Allocator>
222bool
223operator==(const set<Key, Compare, Allocator>& x,
224           const set<Key, Compare, Allocator>& y);
225
226template <class Key, class Compare, class Allocator>
227bool
228operator< (const set<Key, Compare, Allocator>& x,
229           const set<Key, Compare, Allocator>& y);                                // removed in C++20
230
231template <class Key, class Compare, class Allocator>
232bool
233operator!=(const set<Key, Compare, Allocator>& x,
234           const set<Key, Compare, Allocator>& y);                                // removed in C++20
235
236template <class Key, class Compare, class Allocator>
237bool
238operator> (const set<Key, Compare, Allocator>& x,
239           const set<Key, Compare, Allocator>& y);                                // removed in C++20
240
241template <class Key, class Compare, class Allocator>
242bool
243operator>=(const set<Key, Compare, Allocator>& x,
244           const set<Key, Compare, Allocator>& y);                                // removed in C++20
245
246template <class Key, class Compare, class Allocator>
247bool
248operator<=(const set<Key, Compare, Allocator>& x,
249           const set<Key, Compare, Allocator>& y);                                // removed in C++20
250
251template<class Key, class Compare, class Allocator>
252  synth-three-way-result<Key> operator<=>(const set<Key, Compare, Allocator>& x,
253                                          const set<Key, Compare, Allocator>& y); // since C++20
254
255// specialized algorithms:
256template <class Key, class Compare, class Allocator>
257void
258swap(set<Key, Compare, Allocator>& x, set<Key, Compare, Allocator>& y)
259    noexcept(noexcept(x.swap(y)));
260
261template <class Key, class Compare, class Allocator, class Predicate>
262typename set<Key, Compare, Allocator>::size_type
263erase_if(set<Key, Compare, Allocator>& c, Predicate pred);  // C++20
264
265template <class Key, class Compare = less<Key>,
266          class Allocator = allocator<Key>>
267class multiset
268{
269public:
270    // types:
271    typedef Key                                      key_type;
272    typedef key_type                                 value_type;
273    typedef Compare                                  key_compare;
274    typedef key_compare                              value_compare;
275    typedef Allocator                                allocator_type;
276    typedef typename allocator_type::reference       reference;
277    typedef typename allocator_type::const_reference const_reference;
278    typedef typename allocator_type::size_type       size_type;
279    typedef typename allocator_type::difference_type difference_type;
280    typedef typename allocator_type::pointer         pointer;
281    typedef typename allocator_type::const_pointer   const_pointer;
282
283    typedef implementation-defined                   iterator;
284    typedef implementation-defined                   const_iterator;
285    typedef std::reverse_iterator<iterator>          reverse_iterator;
286    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;
287    typedef unspecified                              node_type;               // C++17
288
289    // construct/copy/destroy:
290    multiset()
291        noexcept(
292            is_nothrow_default_constructible<allocator_type>::value &&
293            is_nothrow_default_constructible<key_compare>::value &&
294            is_nothrow_copy_constructible<key_compare>::value);
295    explicit multiset(const value_compare& comp);
296    multiset(const value_compare& comp, const allocator_type& a);
297    template <class InputIterator>
298        multiset(InputIterator first, InputIterator last,
299                 const value_compare& comp = value_compare());
300    template <class InputIterator>
301        multiset(InputIterator first, InputIterator last,
302                 const value_compare& comp, const allocator_type& a);
303    template<container-compatible-range<value_type> R>
304      multiset(from_range_t, R&& rg,
305               const Compare& comp = Compare(), const Allocator& = Allocator()); // C++23
306    multiset(const multiset& s);
307    multiset(multiset&& s)
308        noexcept(
309            is_nothrow_move_constructible<allocator_type>::value &&
310            is_nothrow_move_constructible<key_compare>::value);
311    explicit multiset(const allocator_type& a);
312    multiset(const multiset& s, const allocator_type& a);
313    multiset(multiset&& s, const allocator_type& a);
314    multiset(initializer_list<value_type> il, const value_compare& comp = value_compare());
315    multiset(initializer_list<value_type> il, const value_compare& comp,
316             const allocator_type& a);
317    template <class InputIterator>
318        multiset(InputIterator first, InputIterator last, const allocator_type& a)
319            : set(first, last, Compare(), a) {}  // C++14
320    template<container-compatible-range<value_type> R>
321      multiset(from_range_t, R&& rg, const Allocator& a))
322        : multiset(from_range, std::forward<R>(rg), Compare(), a) { } // C++23
323    multiset(initializer_list<value_type> il, const allocator_type& a)
324        : set(il, Compare(), a) {}  // C++14
325    ~multiset();
326
327    multiset& operator=(const multiset& s);
328    multiset& operator=(multiset&& s)
329        noexcept(
330            allocator_type::propagate_on_container_move_assignment::value &&
331            is_nothrow_move_assignable<allocator_type>::value &&
332            is_nothrow_move_assignable<key_compare>::value);
333    multiset& operator=(initializer_list<value_type> il);
334
335    // iterators:
336          iterator begin() noexcept;
337    const_iterator begin() const noexcept;
338          iterator end() noexcept;
339    const_iterator end()   const noexcept;
340
341          reverse_iterator rbegin() noexcept;
342    const_reverse_iterator rbegin() const noexcept;
343          reverse_iterator rend() noexcept;
344    const_reverse_iterator rend()   const noexcept;
345
346    const_iterator         cbegin()  const noexcept;
347    const_iterator         cend()    const noexcept;
348    const_reverse_iterator crbegin() const noexcept;
349    const_reverse_iterator crend()   const noexcept;
350
351    // capacity:
352    bool      empty()    const noexcept;
353    size_type size()     const noexcept;
354    size_type max_size() const noexcept;
355
356    // modifiers:
357    template <class... Args>
358        iterator emplace(Args&&... args);
359    template <class... Args>
360        iterator emplace_hint(const_iterator position, Args&&... args);
361    iterator insert(const value_type& v);
362    iterator insert(value_type&& v);
363    iterator insert(const_iterator position, const value_type& v);
364    iterator insert(const_iterator position, value_type&& v);
365    template <class InputIterator>
366        void insert(InputIterator first, InputIterator last);
367    template<container-compatible-range<value_type> R>
368      void insert_range(R&& rg);                                                      // C++23
369    void insert(initializer_list<value_type> il);
370
371    node_type extract(const_iterator position);                                       // C++17
372    node_type extract(const key_type& x);                                             // C++17
373    iterator insert(node_type&& nh);                                                  // C++17
374    iterator insert(const_iterator hint, node_type&& nh);                             // C++17
375
376    iterator  erase(const_iterator position);
377    iterator  erase(iterator position);  // C++14
378    size_type erase(const key_type& k);
379    iterator  erase(const_iterator first, const_iterator last);
380    void clear() noexcept;
381
382    template<class C2>
383      void merge(multiset<Key, C2, Allocator>& source);    // C++17
384    template<class C2>
385      void merge(multiset<Key, C2, Allocator>&& source);   // C++17
386    template<class C2>
387      void merge(set<Key, C2, Allocator>& source);         // C++17
388    template<class C2>
389      void merge(set<Key, C2, Allocator>&& source);        // C++17
390
391    void swap(multiset& s)
392        noexcept(
393            __is_nothrow_swappable<key_compare>::value &&
394            (!allocator_type::propagate_on_container_swap::value ||
395             __is_nothrow_swappable<allocator_type>::value));
396
397    // observers:
398    allocator_type get_allocator() const noexcept;
399    key_compare    key_comp()      const;
400    value_compare  value_comp()    const;
401
402    // set operations:
403          iterator find(const key_type& k);
404    const_iterator find(const key_type& k) const;
405    template<typename K>
406        iterator find(const K& x);
407    template<typename K>
408        const_iterator find(const K& x) const;  // C++14
409
410    template<typename K>
411        size_type count(const K& x) const;      // C++14
412    size_type      count(const key_type& k) const;
413
414    bool           contains(const key_type& x) const;  // C++20
415    template<class K> bool contains(const K& x) const; // C++20
416
417          iterator lower_bound(const key_type& k);
418    const_iterator lower_bound(const key_type& k) const;
419    template<typename K>
420        iterator lower_bound(const K& x);              // C++14
421    template<typename K>
422        const_iterator lower_bound(const K& x) const;  // C++14
423
424          iterator upper_bound(const key_type& k);
425    const_iterator upper_bound(const key_type& k) const;
426    template<typename K>
427        iterator upper_bound(const K& x);              // C++14
428    template<typename K>
429        const_iterator upper_bound(const K& x) const;  // C++14
430
431    pair<iterator,iterator>             equal_range(const key_type& k);
432    pair<const_iterator,const_iterator> equal_range(const key_type& k) const;
433    template<typename K>
434        pair<iterator,iterator>             equal_range(const K& x);        // C++14
435    template<typename K>
436        pair<const_iterator,const_iterator> equal_range(const K& x) const;  // C++14
437};
438
439template <class InputIterator,
440      class Compare = less<typename iterator_traits<InputIterator>::value_type>,
441      class Allocator = allocator<typename iterator_traits<InputIterator>::value_type>>
442multiset(InputIterator, InputIterator,
443    Compare = Compare(), Allocator = Allocator())
444  -> multiset<typename iterator_traits<InputIterator>::value_type, Compare, Allocator>; // C++17
445
446template<ranges::input_range R, class Compare = less<ranges::range_value_t<R>>,
447          class Allocator = allocator<ranges::range_value_t<R>>>
448  multiset(from_range_t, R&&, Compare = Compare(), Allocator = Allocator())
449    -> multiset<ranges::range_value_t<R>, Compare, Allocator>;
450
451template<class Key, class Compare = less<Key>, class Allocator = allocator<Key>>
452multiset(initializer_list<Key>, Compare = Compare(), Allocator = Allocator())
453  -> multiset<Key, Compare, Allocator>; // C++17
454
455template<class InputIterator, class Allocator>
456multiset(InputIterator, InputIterator, Allocator)
457  -> multiset<typename iterator_traits<InputIterator>::value_type,
458          less<typename iterator_traits<InputIterator>::value_type>, Allocator>; // C++17
459
460template<ranges::input_range R, class Allocator>
461  multiset(from_range_t, R&&, Allocator)
462    -> multiset<ranges::range_value_t<R>, less<ranges::range_value_t<R>>, Allocator>;
463
464template<class Key, class Allocator>
465multiset(initializer_list<Key>, Allocator) -> multiset<Key, less<Key>, Allocator>; // C++17
466
467template <class Key, class Compare, class Allocator>
468bool
469operator==(const multiset<Key, Compare, Allocator>& x,
470           const multiset<Key, Compare, Allocator>& y);
471
472template <class Key, class Compare, class Allocator>
473bool
474operator< (const multiset<Key, Compare, Allocator>& x,
475           const multiset<Key, Compare, Allocator>& y);                                // removed in C++20
476
477template <class Key, class Compare, class Allocator>
478bool
479operator!=(const multiset<Key, Compare, Allocator>& x,
480           const multiset<Key, Compare, Allocator>& y);                                // removed in C++20
481
482template <class Key, class Compare, class Allocator>
483bool
484operator> (const multiset<Key, Compare, Allocator>& x,
485           const multiset<Key, Compare, Allocator>& y);                                // removed in C++20
486
487template <class Key, class Compare, class Allocator>
488bool
489operator>=(const multiset<Key, Compare, Allocator>& x,
490           const multiset<Key, Compare, Allocator>& y);                                // removed in C++20
491
492template <class Key, class Compare, class Allocator>
493bool
494operator<=(const multiset<Key, Compare, Allocator>& x,
495           const multiset<Key, Compare, Allocator>& y);                                // removed in C++20
496
497template<class Key, class Compare, class Allocator>
498  synth-three-way-result<Key> operator<=>(const multiset<Key, Compare, Allocator>& x,
499                                          const multiset<Key, Compare, Allocator>& y); // since C++20
500
501// specialized algorithms:
502template <class Key, class Compare, class Allocator>
503void
504swap(multiset<Key, Compare, Allocator>& x, multiset<Key, Compare, Allocator>& y)
505    noexcept(noexcept(x.swap(y)));
506
507template <class Key, class Compare, class Allocator, class Predicate>
508typename multiset<Key, Compare, Allocator>::size_type
509erase_if(multiset<Key, Compare, Allocator>& c, Predicate pred);  // C++20
510
511}  // std
512
513*/
514
515#include <__algorithm/equal.h>
516#include <__algorithm/lexicographical_compare.h>
517#include <__algorithm/lexicographical_compare_three_way.h>
518#include <__assert>
519#include <__config>
520#include <__functional/is_transparent.h>
521#include <__functional/operations.h>
522#include <__iterator/erase_if_container.h>
523#include <__iterator/iterator_traits.h>
524#include <__iterator/ranges_iterator_traits.h>
525#include <__iterator/reverse_iterator.h>
526#include <__memory/allocator.h>
527#include <__memory_resource/polymorphic_allocator.h>
528#include <__node_handle>
529#include <__ranges/concepts.h>
530#include <__ranges/container_compatible_range.h>
531#include <__ranges/from_range.h>
532#include <__tree>
533#include <__type_traits/is_allocator.h>
534#include <__utility/forward.h>
535#include <version>
536
537// standard-mandated includes
538
539// [iterator.range]
540#include <__iterator/access.h>
541#include <__iterator/data.h>
542#include <__iterator/empty.h>
543#include <__iterator/reverse_access.h>
544#include <__iterator/size.h>
545
546// [associative.set.syn]
547#include <compare>
548#include <initializer_list>
549
550#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
551#  pragma GCC system_header
552#endif
553
554_LIBCPP_PUSH_MACROS
555#include <__undef_macros>
556
557_LIBCPP_BEGIN_NAMESPACE_STD
558
559template <class _Key, class _Compare, class _Allocator>
560class multiset;
561
562template <class _Key, class _Compare = less<_Key>, class _Allocator = allocator<_Key> >
563class _LIBCPP_TEMPLATE_VIS set {
564public:
565  // types:
566  typedef _Key key_type;
567  typedef key_type value_type;
568  typedef __type_identity_t<_Compare> key_compare;
569  typedef key_compare value_compare;
570  typedef __type_identity_t<_Allocator> allocator_type;
571  typedef value_type& reference;
572  typedef const value_type& const_reference;
573
574  static_assert(is_same<typename allocator_type::value_type, value_type>::value,
575                "Allocator::value_type must be same type as value_type");
576
577private:
578  typedef __tree<value_type, value_compare, allocator_type> __base;
579  typedef allocator_traits<allocator_type> __alloc_traits;
580
581  static_assert(__check_valid_allocator<allocator_type>::value, "");
582
583  __base __tree_;
584
585public:
586  typedef typename __base::pointer pointer;
587  typedef typename __base::const_pointer const_pointer;
588  typedef typename __base::size_type size_type;
589  typedef typename __base::difference_type difference_type;
590  typedef typename __base::const_iterator iterator;
591  typedef typename __base::const_iterator const_iterator;
592  typedef std::reverse_iterator<iterator> reverse_iterator;
593  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
594
595#if _LIBCPP_STD_VER >= 17
596  typedef __set_node_handle<typename __base::__node, allocator_type> node_type;
597  typedef __insert_return_type<iterator, node_type> insert_return_type;
598#endif
599
600  template <class _Key2, class _Compare2, class _Alloc2>
601  friend class _LIBCPP_TEMPLATE_VIS set;
602  template <class _Key2, class _Compare2, class _Alloc2>
603  friend class _LIBCPP_TEMPLATE_VIS multiset;
604
605  _LIBCPP_HIDE_FROM_ABI set() _NOEXCEPT_(
606      is_nothrow_default_constructible<allocator_type>::value&& is_nothrow_default_constructible<key_compare>::value&&
607          is_nothrow_copy_constructible<key_compare>::value)
608      : __tree_(value_compare()) {}
609
610  _LIBCPP_HIDE_FROM_ABI explicit set(const value_compare& __comp) _NOEXCEPT_(
611      is_nothrow_default_constructible<allocator_type>::value&& is_nothrow_copy_constructible<key_compare>::value)
612      : __tree_(__comp) {}
613
614  _LIBCPP_HIDE_FROM_ABI explicit set(const value_compare& __comp, const allocator_type& __a) : __tree_(__comp, __a) {}
615  template <class _InputIterator>
616  _LIBCPP_HIDE_FROM_ABI set(_InputIterator __f, _InputIterator __l, const value_compare& __comp = value_compare())
617      : __tree_(__comp) {
618    insert(__f, __l);
619  }
620
621  template <class _InputIterator>
622  _LIBCPP_HIDE_FROM_ABI
623  set(_InputIterator __f, _InputIterator __l, const value_compare& __comp, const allocator_type& __a)
624      : __tree_(__comp, __a) {
625    insert(__f, __l);
626  }
627
628#if _LIBCPP_STD_VER >= 23
629  template <_ContainerCompatibleRange<value_type> _Range>
630  _LIBCPP_HIDE_FROM_ABI
631  set(from_range_t,
632      _Range&& __range,
633      const key_compare& __comp = key_compare(),
634      const allocator_type& __a = allocator_type())
635      : __tree_(__comp, __a) {
636    insert_range(std::forward<_Range>(__range));
637  }
638#endif
639
640#if _LIBCPP_STD_VER >= 14
641  template <class _InputIterator>
642  _LIBCPP_HIDE_FROM_ABI set(_InputIterator __f, _InputIterator __l, const allocator_type& __a)
643      : set(__f, __l, key_compare(), __a) {}
644#endif
645
646#if _LIBCPP_STD_VER >= 23
647  template <_ContainerCompatibleRange<value_type> _Range>
648  _LIBCPP_HIDE_FROM_ABI set(from_range_t, _Range&& __range, const allocator_type& __a)
649      : set(from_range, std::forward<_Range>(__range), key_compare(), __a) {}
650#endif
651
652  _LIBCPP_HIDE_FROM_ABI set(const set& __s) : __tree_(__s.__tree_) { insert(__s.begin(), __s.end()); }
653
654  _LIBCPP_HIDE_FROM_ABI set& operator=(const set& __s) {
655    __tree_ = __s.__tree_;
656    return *this;
657  }
658
659#ifndef _LIBCPP_CXX03_LANG
660  _LIBCPP_HIDE_FROM_ABI set(set&& __s) noexcept(is_nothrow_move_constructible<__base>::value)
661      : __tree_(std::move(__s.__tree_)) {}
662#endif // _LIBCPP_CXX03_LANG
663
664  _LIBCPP_HIDE_FROM_ABI explicit set(const allocator_type& __a) : __tree_(__a) {}
665
666  _LIBCPP_HIDE_FROM_ABI set(const set& __s, const allocator_type& __a) : __tree_(__s.__tree_.value_comp(), __a) {
667    insert(__s.begin(), __s.end());
668  }
669
670#ifndef _LIBCPP_CXX03_LANG
671  _LIBCPP_HIDE_FROM_ABI set(set&& __s, const allocator_type& __a);
672
673  _LIBCPP_HIDE_FROM_ABI set(initializer_list<value_type> __il, const value_compare& __comp = value_compare())
674      : __tree_(__comp) {
675    insert(__il.begin(), __il.end());
676  }
677
678  _LIBCPP_HIDE_FROM_ABI set(initializer_list<value_type> __il, const value_compare& __comp, const allocator_type& __a)
679      : __tree_(__comp, __a) {
680    insert(__il.begin(), __il.end());
681  }
682
683#  if _LIBCPP_STD_VER >= 14
684  _LIBCPP_HIDE_FROM_ABI set(initializer_list<value_type> __il, const allocator_type& __a)
685      : set(__il, key_compare(), __a) {}
686#  endif
687
688  _LIBCPP_HIDE_FROM_ABI set& operator=(initializer_list<value_type> __il) {
689    __tree_.__assign_unique(__il.begin(), __il.end());
690    return *this;
691  }
692
693  _LIBCPP_HIDE_FROM_ABI set& operator=(set&& __s) noexcept(is_nothrow_move_assignable<__base>::value) {
694    __tree_ = std::move(__s.__tree_);
695    return *this;
696  }
697#endif // _LIBCPP_CXX03_LANG
698
699  _LIBCPP_HIDE_FROM_ABI ~set() { static_assert(sizeof(__diagnose_non_const_comparator<_Key, _Compare>()), ""); }
700
701  _LIBCPP_HIDE_FROM_ABI iterator begin() _NOEXCEPT { return __tree_.begin(); }
702  _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT { return __tree_.begin(); }
703  _LIBCPP_HIDE_FROM_ABI iterator end() _NOEXCEPT { return __tree_.end(); }
704  _LIBCPP_HIDE_FROM_ABI const_iterator end() const _NOEXCEPT { return __tree_.end(); }
705
706  _LIBCPP_HIDE_FROM_ABI reverse_iterator rbegin() _NOEXCEPT { return reverse_iterator(end()); }
707  _LIBCPP_HIDE_FROM_ABI const_reverse_iterator rbegin() const _NOEXCEPT { return const_reverse_iterator(end()); }
708  _LIBCPP_HIDE_FROM_ABI reverse_iterator rend() _NOEXCEPT { return reverse_iterator(begin()); }
709  _LIBCPP_HIDE_FROM_ABI const_reverse_iterator rend() const _NOEXCEPT { return const_reverse_iterator(begin()); }
710
711  _LIBCPP_HIDE_FROM_ABI const_iterator cbegin() const _NOEXCEPT { return begin(); }
712  _LIBCPP_HIDE_FROM_ABI const_iterator cend() const _NOEXCEPT { return end(); }
713  _LIBCPP_HIDE_FROM_ABI const_reverse_iterator crbegin() const _NOEXCEPT { return rbegin(); }
714  _LIBCPP_HIDE_FROM_ABI const_reverse_iterator crend() const _NOEXCEPT { return rend(); }
715
716  _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI bool empty() const _NOEXCEPT { return __tree_.size() == 0; }
717  _LIBCPP_HIDE_FROM_ABI size_type size() const _NOEXCEPT { return __tree_.size(); }
718  _LIBCPP_HIDE_FROM_ABI size_type max_size() const _NOEXCEPT { return __tree_.max_size(); }
719
720  // modifiers:
721#ifndef _LIBCPP_CXX03_LANG
722  template <class... _Args>
723  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> emplace(_Args&&... __args) {
724    return __tree_.__emplace_unique(std::forward<_Args>(__args)...);
725  }
726  template <class... _Args>
727  _LIBCPP_HIDE_FROM_ABI iterator emplace_hint(const_iterator __p, _Args&&... __args) {
728    return __tree_.__emplace_hint_unique(__p, std::forward<_Args>(__args)...);
729  }
730#endif // _LIBCPP_CXX03_LANG
731
732  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert(const value_type& __v) { return __tree_.__insert_unique(__v); }
733  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, const value_type& __v) {
734    return __tree_.__insert_unique(__p, __v);
735  }
736
737  template <class _InputIterator>
738  _LIBCPP_HIDE_FROM_ABI void insert(_InputIterator __f, _InputIterator __l) {
739    for (const_iterator __e = cend(); __f != __l; ++__f)
740      __tree_.__insert_unique(__e, *__f);
741  }
742
743#if _LIBCPP_STD_VER >= 23
744  template <_ContainerCompatibleRange<value_type> _Range>
745  _LIBCPP_HIDE_FROM_ABI void insert_range(_Range&& __range) {
746    const_iterator __end = cend();
747    for (auto&& __element : __range) {
748      __tree_.__insert_unique(__end, std::forward<decltype(__element)>(__element));
749    }
750  }
751#endif
752
753#ifndef _LIBCPP_CXX03_LANG
754  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert(value_type&& __v) {
755    return __tree_.__insert_unique(std::move(__v));
756  }
757
758  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, value_type&& __v) {
759    return __tree_.__insert_unique(__p, std::move(__v));
760  }
761
762  _LIBCPP_HIDE_FROM_ABI void insert(initializer_list<value_type> __il) { insert(__il.begin(), __il.end()); }
763#endif // _LIBCPP_CXX03_LANG
764
765  _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __p) { return __tree_.erase(__p); }
766  _LIBCPP_HIDE_FROM_ABI size_type erase(const key_type& __k) { return __tree_.__erase_unique(__k); }
767  _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __f, const_iterator __l) { return __tree_.erase(__f, __l); }
768  _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT { __tree_.clear(); }
769
770#if _LIBCPP_STD_VER >= 17
771  _LIBCPP_HIDE_FROM_ABI insert_return_type insert(node_type&& __nh) {
772    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(__nh.empty() || __nh.get_allocator() == get_allocator(),
773                                        "node_type with incompatible allocator passed to set::insert()");
774    return __tree_.template __node_handle_insert_unique< node_type, insert_return_type>(std::move(__nh));
775  }
776  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __hint, node_type&& __nh) {
777    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(__nh.empty() || __nh.get_allocator() == get_allocator(),
778                                        "node_type with incompatible allocator passed to set::insert()");
779    return __tree_.template __node_handle_insert_unique<node_type>(__hint, std::move(__nh));
780  }
781  _LIBCPP_HIDE_FROM_ABI node_type extract(key_type const& __key) {
782    return __tree_.template __node_handle_extract<node_type>(__key);
783  }
784  _LIBCPP_HIDE_FROM_ABI node_type extract(const_iterator __it) {
785    return __tree_.template __node_handle_extract<node_type>(__it);
786  }
787  template <class _Compare2>
788  _LIBCPP_HIDE_FROM_ABI void merge(set<key_type, _Compare2, allocator_type>& __source) {
789    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
790        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
791    __tree_.__node_handle_merge_unique(__source.__tree_);
792  }
793  template <class _Compare2>
794  _LIBCPP_HIDE_FROM_ABI void merge(set<key_type, _Compare2, allocator_type>&& __source) {
795    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
796        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
797    __tree_.__node_handle_merge_unique(__source.__tree_);
798  }
799  template <class _Compare2>
800  _LIBCPP_HIDE_FROM_ABI void merge(multiset<key_type, _Compare2, allocator_type>& __source) {
801    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
802        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
803    __tree_.__node_handle_merge_unique(__source.__tree_);
804  }
805  template <class _Compare2>
806  _LIBCPP_HIDE_FROM_ABI void merge(multiset<key_type, _Compare2, allocator_type>&& __source) {
807    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
808        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
809    __tree_.__node_handle_merge_unique(__source.__tree_);
810  }
811#endif
812
813  _LIBCPP_HIDE_FROM_ABI void swap(set& __s) _NOEXCEPT_(__is_nothrow_swappable_v<__base>) { __tree_.swap(__s.__tree_); }
814
815  _LIBCPP_HIDE_FROM_ABI allocator_type get_allocator() const _NOEXCEPT { return __tree_.__alloc(); }
816  _LIBCPP_HIDE_FROM_ABI key_compare key_comp() const { return __tree_.value_comp(); }
817  _LIBCPP_HIDE_FROM_ABI value_compare value_comp() const { return __tree_.value_comp(); }
818
819  // set operations:
820  _LIBCPP_HIDE_FROM_ABI iterator find(const key_type& __k) { return __tree_.find(__k); }
821  _LIBCPP_HIDE_FROM_ABI const_iterator find(const key_type& __k) const { return __tree_.find(__k); }
822#if _LIBCPP_STD_VER >= 14
823  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
824  _LIBCPP_HIDE_FROM_ABI iterator find(const _K2& __k) {
825    return __tree_.find(__k);
826  }
827  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
828  _LIBCPP_HIDE_FROM_ABI const_iterator find(const _K2& __k) const {
829    return __tree_.find(__k);
830  }
831#endif
832
833  _LIBCPP_HIDE_FROM_ABI size_type count(const key_type& __k) const { return __tree_.__count_unique(__k); }
834#if _LIBCPP_STD_VER >= 14
835  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
836  _LIBCPP_HIDE_FROM_ABI size_type count(const _K2& __k) const {
837    return __tree_.__count_multi(__k);
838  }
839#endif
840
841#if _LIBCPP_STD_VER >= 20
842  _LIBCPP_HIDE_FROM_ABI bool contains(const key_type& __k) const { return find(__k) != end(); }
843  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
844  _LIBCPP_HIDE_FROM_ABI bool contains(const _K2& __k) const {
845    return find(__k) != end();
846  }
847#endif // _LIBCPP_STD_VER >= 20
848
849  _LIBCPP_HIDE_FROM_ABI iterator lower_bound(const key_type& __k) { return __tree_.lower_bound(__k); }
850  _LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const key_type& __k) const { return __tree_.lower_bound(__k); }
851#if _LIBCPP_STD_VER >= 14
852  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
853  _LIBCPP_HIDE_FROM_ABI iterator lower_bound(const _K2& __k) {
854    return __tree_.lower_bound(__k);
855  }
856
857  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
858  _LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const _K2& __k) const {
859    return __tree_.lower_bound(__k);
860  }
861#endif
862
863  _LIBCPP_HIDE_FROM_ABI iterator upper_bound(const key_type& __k) { return __tree_.upper_bound(__k); }
864  _LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const key_type& __k) const { return __tree_.upper_bound(__k); }
865#if _LIBCPP_STD_VER >= 14
866  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
867  _LIBCPP_HIDE_FROM_ABI iterator upper_bound(const _K2& __k) {
868    return __tree_.upper_bound(__k);
869  }
870  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
871  _LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const _K2& __k) const {
872    return __tree_.upper_bound(__k);
873  }
874#endif
875
876  _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> equal_range(const key_type& __k) {
877    return __tree_.__equal_range_unique(__k);
878  }
879  _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator> equal_range(const key_type& __k) const {
880    return __tree_.__equal_range_unique(__k);
881  }
882#if _LIBCPP_STD_VER >= 14
883  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
884  _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> equal_range(const _K2& __k) {
885    return __tree_.__equal_range_multi(__k);
886  }
887  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
888  _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator> equal_range(const _K2& __k) const {
889    return __tree_.__equal_range_multi(__k);
890  }
891#endif
892};
893
894#if _LIBCPP_STD_VER >= 17
895template <class _InputIterator,
896          class _Compare   = less<__iter_value_type<_InputIterator>>,
897          class _Allocator = allocator<__iter_value_type<_InputIterator>>,
898          class            = enable_if_t<__has_input_iterator_category<_InputIterator>::value, void>,
899          class            = enable_if_t<__is_allocator<_Allocator>::value, void>,
900          class            = enable_if_t<!__is_allocator<_Compare>::value, void>>
901set(_InputIterator, _InputIterator, _Compare = _Compare(), _Allocator = _Allocator())
902    -> set<__iter_value_type<_InputIterator>, _Compare, _Allocator>;
903
904#  if _LIBCPP_STD_VER >= 23
905template <ranges::input_range _Range,
906          class _Compare   = less<ranges::range_value_t<_Range>>,
907          class _Allocator = allocator<ranges::range_value_t<_Range>>,
908          class            = enable_if_t<__is_allocator<_Allocator>::value, void>,
909          class            = enable_if_t<!__is_allocator<_Compare>::value, void>>
910set(from_range_t, _Range&&, _Compare = _Compare(), _Allocator = _Allocator())
911    -> set<ranges::range_value_t<_Range>, _Compare, _Allocator>;
912#  endif
913
914template <class _Key,
915          class _Compare   = less<_Key>,
916          class _Allocator = allocator<_Key>,
917          class            = enable_if_t<!__is_allocator<_Compare>::value, void>,
918          class            = enable_if_t<__is_allocator<_Allocator>::value, void>>
919set(initializer_list<_Key>, _Compare = _Compare(), _Allocator = _Allocator()) -> set<_Key, _Compare, _Allocator>;
920
921template <class _InputIterator,
922          class _Allocator,
923          class = enable_if_t<__has_input_iterator_category<_InputIterator>::value, void>,
924          class = enable_if_t<__is_allocator<_Allocator>::value, void>>
925set(_InputIterator,
926    _InputIterator,
927    _Allocator) -> set<__iter_value_type<_InputIterator>, less<__iter_value_type<_InputIterator>>, _Allocator>;
928
929#  if _LIBCPP_STD_VER >= 23
930template <ranges::input_range _Range, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value, void>>
931set(from_range_t,
932    _Range&&,
933    _Allocator) -> set<ranges::range_value_t<_Range>, less<ranges::range_value_t<_Range>>, _Allocator>;
934#  endif
935
936template <class _Key, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value, void>>
937set(initializer_list<_Key>, _Allocator) -> set<_Key, less<_Key>, _Allocator>;
938#endif
939
940#ifndef _LIBCPP_CXX03_LANG
941
942template <class _Key, class _Compare, class _Allocator>
943set<_Key, _Compare, _Allocator>::set(set&& __s, const allocator_type& __a) : __tree_(std::move(__s.__tree_), __a) {
944  if (__a != __s.get_allocator()) {
945    const_iterator __e = cend();
946    while (!__s.empty())
947      insert(__e, std::move(__s.__tree_.remove(__s.begin())->__value_));
948  }
949}
950
951#endif // _LIBCPP_CXX03_LANG
952
953template <class _Key, class _Compare, class _Allocator>
954inline _LIBCPP_HIDE_FROM_ABI bool
955operator==(const set<_Key, _Compare, _Allocator>& __x, const set<_Key, _Compare, _Allocator>& __y) {
956  return __x.size() == __y.size() && std::equal(__x.begin(), __x.end(), __y.begin());
957}
958
959#if _LIBCPP_STD_VER <= 17
960
961template <class _Key, class _Compare, class _Allocator>
962inline _LIBCPP_HIDE_FROM_ABI bool
963operator<(const set<_Key, _Compare, _Allocator>& __x, const set<_Key, _Compare, _Allocator>& __y) {
964  return std::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
965}
966
967template <class _Key, class _Compare, class _Allocator>
968inline _LIBCPP_HIDE_FROM_ABI bool
969operator!=(const set<_Key, _Compare, _Allocator>& __x, const set<_Key, _Compare, _Allocator>& __y) {
970  return !(__x == __y);
971}
972
973template <class _Key, class _Compare, class _Allocator>
974inline _LIBCPP_HIDE_FROM_ABI bool
975operator>(const set<_Key, _Compare, _Allocator>& __x, const set<_Key, _Compare, _Allocator>& __y) {
976  return __y < __x;
977}
978
979template <class _Key, class _Compare, class _Allocator>
980inline _LIBCPP_HIDE_FROM_ABI bool
981operator>=(const set<_Key, _Compare, _Allocator>& __x, const set<_Key, _Compare, _Allocator>& __y) {
982  return !(__x < __y);
983}
984
985template <class _Key, class _Compare, class _Allocator>
986inline _LIBCPP_HIDE_FROM_ABI bool
987operator<=(const set<_Key, _Compare, _Allocator>& __x, const set<_Key, _Compare, _Allocator>& __y) {
988  return !(__y < __x);
989}
990
991#else // _LIBCPP_STD_VER <= 17
992
993template <class _Key, class _Allocator>
994_LIBCPP_HIDE_FROM_ABI __synth_three_way_result<_Key>
995operator<=>(const set<_Key, _Allocator>& __x, const set<_Key, _Allocator>& __y) {
996  return std::lexicographical_compare_three_way(__x.begin(), __x.end(), __y.begin(), __y.end(), std::__synth_three_way);
997}
998
999#endif // _LIBCPP_STD_VER <= 17
1000
1001// specialized algorithms:
1002template <class _Key, class _Compare, class _Allocator>
1003inline _LIBCPP_HIDE_FROM_ABI void swap(set<_Key, _Compare, _Allocator>& __x, set<_Key, _Compare, _Allocator>& __y)
1004    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) {
1005  __x.swap(__y);
1006}
1007
1008#if _LIBCPP_STD_VER >= 20
1009template <class _Key, class _Compare, class _Allocator, class _Predicate>
1010inline _LIBCPP_HIDE_FROM_ABI typename set<_Key, _Compare, _Allocator>::size_type
1011erase_if(set<_Key, _Compare, _Allocator>& __c, _Predicate __pred) {
1012  return std::__libcpp_erase_if_container(__c, __pred);
1013}
1014#endif
1015
1016template <class _Key, class _Compare = less<_Key>, class _Allocator = allocator<_Key> >
1017class _LIBCPP_TEMPLATE_VIS multiset {
1018public:
1019  // types:
1020  typedef _Key key_type;
1021  typedef key_type value_type;
1022  typedef __type_identity_t<_Compare> key_compare;
1023  typedef key_compare value_compare;
1024  typedef __type_identity_t<_Allocator> allocator_type;
1025  typedef value_type& reference;
1026  typedef const value_type& const_reference;
1027
1028  static_assert(is_same<typename allocator_type::value_type, value_type>::value,
1029                "Allocator::value_type must be same type as value_type");
1030
1031private:
1032  typedef __tree<value_type, value_compare, allocator_type> __base;
1033  typedef allocator_traits<allocator_type> __alloc_traits;
1034
1035  static_assert(__check_valid_allocator<allocator_type>::value, "");
1036
1037  __base __tree_;
1038
1039public:
1040  typedef typename __base::pointer pointer;
1041  typedef typename __base::const_pointer const_pointer;
1042  typedef typename __base::size_type size_type;
1043  typedef typename __base::difference_type difference_type;
1044  typedef typename __base::const_iterator iterator;
1045  typedef typename __base::const_iterator const_iterator;
1046  typedef std::reverse_iterator<iterator> reverse_iterator;
1047  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
1048
1049#if _LIBCPP_STD_VER >= 17
1050  typedef __set_node_handle<typename __base::__node, allocator_type> node_type;
1051#endif
1052
1053  template <class _Key2, class _Compare2, class _Alloc2>
1054  friend class _LIBCPP_TEMPLATE_VIS set;
1055  template <class _Key2, class _Compare2, class _Alloc2>
1056  friend class _LIBCPP_TEMPLATE_VIS multiset;
1057
1058  // construct/copy/destroy:
1059  _LIBCPP_HIDE_FROM_ABI multiset() _NOEXCEPT_(
1060      is_nothrow_default_constructible<allocator_type>::value&& is_nothrow_default_constructible<key_compare>::value&&
1061          is_nothrow_copy_constructible<key_compare>::value)
1062      : __tree_(value_compare()) {}
1063
1064  _LIBCPP_HIDE_FROM_ABI explicit multiset(const value_compare& __comp) _NOEXCEPT_(
1065      is_nothrow_default_constructible<allocator_type>::value&& is_nothrow_copy_constructible<key_compare>::value)
1066      : __tree_(__comp) {}
1067
1068  _LIBCPP_HIDE_FROM_ABI explicit multiset(const value_compare& __comp, const allocator_type& __a)
1069      : __tree_(__comp, __a) {}
1070  template <class _InputIterator>
1071  _LIBCPP_HIDE_FROM_ABI multiset(_InputIterator __f, _InputIterator __l, const value_compare& __comp = value_compare())
1072      : __tree_(__comp) {
1073    insert(__f, __l);
1074  }
1075
1076#if _LIBCPP_STD_VER >= 14
1077  template <class _InputIterator>
1078  _LIBCPP_HIDE_FROM_ABI multiset(_InputIterator __f, _InputIterator __l, const allocator_type& __a)
1079      : multiset(__f, __l, key_compare(), __a) {}
1080#endif
1081
1082  template <class _InputIterator>
1083  _LIBCPP_HIDE_FROM_ABI
1084  multiset(_InputIterator __f, _InputIterator __l, const value_compare& __comp, const allocator_type& __a)
1085      : __tree_(__comp, __a) {
1086    insert(__f, __l);
1087  }
1088
1089#if _LIBCPP_STD_VER >= 23
1090  template <_ContainerCompatibleRange<value_type> _Range>
1091  _LIBCPP_HIDE_FROM_ABI
1092  multiset(from_range_t,
1093           _Range&& __range,
1094           const key_compare& __comp = key_compare(),
1095           const allocator_type& __a = allocator_type())
1096      : __tree_(__comp, __a) {
1097    insert_range(std::forward<_Range>(__range));
1098  }
1099
1100  template <_ContainerCompatibleRange<value_type> _Range>
1101  _LIBCPP_HIDE_FROM_ABI multiset(from_range_t, _Range&& __range, const allocator_type& __a)
1102      : multiset(from_range, std::forward<_Range>(__range), key_compare(), __a) {}
1103#endif
1104
1105  _LIBCPP_HIDE_FROM_ABI multiset(const multiset& __s)
1106      : __tree_(__s.__tree_.value_comp(),
1107                __alloc_traits::select_on_container_copy_construction(__s.__tree_.__alloc())) {
1108    insert(__s.begin(), __s.end());
1109  }
1110
1111  _LIBCPP_HIDE_FROM_ABI multiset& operator=(const multiset& __s) {
1112    __tree_ = __s.__tree_;
1113    return *this;
1114  }
1115
1116#ifndef _LIBCPP_CXX03_LANG
1117  _LIBCPP_HIDE_FROM_ABI multiset(multiset&& __s) noexcept(is_nothrow_move_constructible<__base>::value)
1118      : __tree_(std::move(__s.__tree_)) {}
1119
1120  _LIBCPP_HIDE_FROM_ABI multiset(multiset&& __s, const allocator_type& __a);
1121#endif // _LIBCPP_CXX03_LANG
1122  _LIBCPP_HIDE_FROM_ABI explicit multiset(const allocator_type& __a) : __tree_(__a) {}
1123  _LIBCPP_HIDE_FROM_ABI multiset(const multiset& __s, const allocator_type& __a)
1124      : __tree_(__s.__tree_.value_comp(), __a) {
1125    insert(__s.begin(), __s.end());
1126  }
1127
1128#ifndef _LIBCPP_CXX03_LANG
1129  _LIBCPP_HIDE_FROM_ABI multiset(initializer_list<value_type> __il, const value_compare& __comp = value_compare())
1130      : __tree_(__comp) {
1131    insert(__il.begin(), __il.end());
1132  }
1133
1134  _LIBCPP_HIDE_FROM_ABI
1135  multiset(initializer_list<value_type> __il, const value_compare& __comp, const allocator_type& __a)
1136      : __tree_(__comp, __a) {
1137    insert(__il.begin(), __il.end());
1138  }
1139
1140#  if _LIBCPP_STD_VER >= 14
1141  _LIBCPP_HIDE_FROM_ABI multiset(initializer_list<value_type> __il, const allocator_type& __a)
1142      : multiset(__il, key_compare(), __a) {}
1143#  endif
1144
1145  _LIBCPP_HIDE_FROM_ABI multiset& operator=(initializer_list<value_type> __il) {
1146    __tree_.__assign_multi(__il.begin(), __il.end());
1147    return *this;
1148  }
1149
1150  _LIBCPP_HIDE_FROM_ABI multiset& operator=(multiset&& __s) _NOEXCEPT_(is_nothrow_move_assignable<__base>::value) {
1151    __tree_ = std::move(__s.__tree_);
1152    return *this;
1153  }
1154#endif // _LIBCPP_CXX03_LANG
1155
1156  _LIBCPP_HIDE_FROM_ABI ~multiset() { static_assert(sizeof(__diagnose_non_const_comparator<_Key, _Compare>()), ""); }
1157
1158  _LIBCPP_HIDE_FROM_ABI iterator begin() _NOEXCEPT { return __tree_.begin(); }
1159  _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT { return __tree_.begin(); }
1160  _LIBCPP_HIDE_FROM_ABI iterator end() _NOEXCEPT { return __tree_.end(); }
1161  _LIBCPP_HIDE_FROM_ABI const_iterator end() const _NOEXCEPT { return __tree_.end(); }
1162
1163  _LIBCPP_HIDE_FROM_ABI reverse_iterator rbegin() _NOEXCEPT { return reverse_iterator(end()); }
1164  _LIBCPP_HIDE_FROM_ABI const_reverse_iterator rbegin() const _NOEXCEPT { return const_reverse_iterator(end()); }
1165  _LIBCPP_HIDE_FROM_ABI reverse_iterator rend() _NOEXCEPT { return reverse_iterator(begin()); }
1166  _LIBCPP_HIDE_FROM_ABI const_reverse_iterator rend() const _NOEXCEPT { return const_reverse_iterator(begin()); }
1167
1168  _LIBCPP_HIDE_FROM_ABI const_iterator cbegin() const _NOEXCEPT { return begin(); }
1169  _LIBCPP_HIDE_FROM_ABI const_iterator cend() const _NOEXCEPT { return end(); }
1170  _LIBCPP_HIDE_FROM_ABI const_reverse_iterator crbegin() const _NOEXCEPT { return rbegin(); }
1171  _LIBCPP_HIDE_FROM_ABI const_reverse_iterator crend() const _NOEXCEPT { return rend(); }
1172
1173  _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI bool empty() const _NOEXCEPT { return __tree_.size() == 0; }
1174  _LIBCPP_HIDE_FROM_ABI size_type size() const _NOEXCEPT { return __tree_.size(); }
1175  _LIBCPP_HIDE_FROM_ABI size_type max_size() const _NOEXCEPT { return __tree_.max_size(); }
1176
1177  // modifiers:
1178#ifndef _LIBCPP_CXX03_LANG
1179  template <class... _Args>
1180  _LIBCPP_HIDE_FROM_ABI iterator emplace(_Args&&... __args) {
1181    return __tree_.__emplace_multi(std::forward<_Args>(__args)...);
1182  }
1183  template <class... _Args>
1184  _LIBCPP_HIDE_FROM_ABI iterator emplace_hint(const_iterator __p, _Args&&... __args) {
1185    return __tree_.__emplace_hint_multi(__p, std::forward<_Args>(__args)...);
1186  }
1187#endif // _LIBCPP_CXX03_LANG
1188
1189  _LIBCPP_HIDE_FROM_ABI iterator insert(const value_type& __v) { return __tree_.__insert_multi(__v); }
1190  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, const value_type& __v) {
1191    return __tree_.__insert_multi(__p, __v);
1192  }
1193
1194  template <class _InputIterator>
1195  _LIBCPP_HIDE_FROM_ABI void insert(_InputIterator __f, _InputIterator __l) {
1196    for (const_iterator __e = cend(); __f != __l; ++__f)
1197      __tree_.__insert_multi(__e, *__f);
1198  }
1199
1200#if _LIBCPP_STD_VER >= 23
1201  template <_ContainerCompatibleRange<value_type> _Range>
1202  _LIBCPP_HIDE_FROM_ABI void insert_range(_Range&& __range) {
1203    const_iterator __end = cend();
1204    for (auto&& __element : __range) {
1205      __tree_.__insert_multi(__end, std::forward<decltype(__element)>(__element));
1206    }
1207  }
1208#endif
1209
1210#ifndef _LIBCPP_CXX03_LANG
1211  _LIBCPP_HIDE_FROM_ABI iterator insert(value_type&& __v) { return __tree_.__insert_multi(std::move(__v)); }
1212
1213  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, value_type&& __v) {
1214    return __tree_.__insert_multi(__p, std::move(__v));
1215  }
1216
1217  _LIBCPP_HIDE_FROM_ABI void insert(initializer_list<value_type> __il) { insert(__il.begin(), __il.end()); }
1218#endif // _LIBCPP_CXX03_LANG
1219
1220  _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __p) { return __tree_.erase(__p); }
1221  _LIBCPP_HIDE_FROM_ABI size_type erase(const key_type& __k) { return __tree_.__erase_multi(__k); }
1222  _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __f, const_iterator __l) { return __tree_.erase(__f, __l); }
1223  _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT { __tree_.clear(); }
1224
1225#if _LIBCPP_STD_VER >= 17
1226  _LIBCPP_HIDE_FROM_ABI iterator insert(node_type&& __nh) {
1227    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(__nh.empty() || __nh.get_allocator() == get_allocator(),
1228                                        "node_type with incompatible allocator passed to multiset::insert()");
1229    return __tree_.template __node_handle_insert_multi<node_type>(std::move(__nh));
1230  }
1231  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __hint, node_type&& __nh) {
1232    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(__nh.empty() || __nh.get_allocator() == get_allocator(),
1233                                        "node_type with incompatible allocator passed to multiset::insert()");
1234    return __tree_.template __node_handle_insert_multi<node_type>(__hint, std::move(__nh));
1235  }
1236  _LIBCPP_HIDE_FROM_ABI node_type extract(key_type const& __key) {
1237    return __tree_.template __node_handle_extract<node_type>(__key);
1238  }
1239  _LIBCPP_HIDE_FROM_ABI node_type extract(const_iterator __it) {
1240    return __tree_.template __node_handle_extract<node_type>(__it);
1241  }
1242  template <class _Compare2>
1243  _LIBCPP_HIDE_FROM_ABI void merge(multiset<key_type, _Compare2, allocator_type>& __source) {
1244    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
1245        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
1246    __tree_.__node_handle_merge_multi(__source.__tree_);
1247  }
1248  template <class _Compare2>
1249  _LIBCPP_HIDE_FROM_ABI void merge(multiset<key_type, _Compare2, allocator_type>&& __source) {
1250    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
1251        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
1252    __tree_.__node_handle_merge_multi(__source.__tree_);
1253  }
1254  template <class _Compare2>
1255  _LIBCPP_HIDE_FROM_ABI void merge(set<key_type, _Compare2, allocator_type>& __source) {
1256    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
1257        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
1258    __tree_.__node_handle_merge_multi(__source.__tree_);
1259  }
1260  template <class _Compare2>
1261  _LIBCPP_HIDE_FROM_ABI void merge(set<key_type, _Compare2, allocator_type>&& __source) {
1262    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
1263        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
1264    __tree_.__node_handle_merge_multi(__source.__tree_);
1265  }
1266#endif
1267
1268  _LIBCPP_HIDE_FROM_ABI void swap(multiset& __s) _NOEXCEPT_(__is_nothrow_swappable_v<__base>) {
1269    __tree_.swap(__s.__tree_);
1270  }
1271
1272  _LIBCPP_HIDE_FROM_ABI allocator_type get_allocator() const _NOEXCEPT { return __tree_.__alloc(); }
1273  _LIBCPP_HIDE_FROM_ABI key_compare key_comp() const { return __tree_.value_comp(); }
1274  _LIBCPP_HIDE_FROM_ABI value_compare value_comp() const { return __tree_.value_comp(); }
1275
1276  // set operations:
1277  _LIBCPP_HIDE_FROM_ABI iterator find(const key_type& __k) { return __tree_.find(__k); }
1278  _LIBCPP_HIDE_FROM_ABI const_iterator find(const key_type& __k) const { return __tree_.find(__k); }
1279#if _LIBCPP_STD_VER >= 14
1280  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
1281  _LIBCPP_HIDE_FROM_ABI iterator find(const _K2& __k) {
1282    return __tree_.find(__k);
1283  }
1284  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
1285  _LIBCPP_HIDE_FROM_ABI const_iterator find(const _K2& __k) const {
1286    return __tree_.find(__k);
1287  }
1288#endif
1289
1290  _LIBCPP_HIDE_FROM_ABI size_type count(const key_type& __k) const { return __tree_.__count_multi(__k); }
1291#if _LIBCPP_STD_VER >= 14
1292  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
1293  _LIBCPP_HIDE_FROM_ABI size_type count(const _K2& __k) const {
1294    return __tree_.__count_multi(__k);
1295  }
1296#endif
1297
1298#if _LIBCPP_STD_VER >= 20
1299  _LIBCPP_HIDE_FROM_ABI bool contains(const key_type& __k) const { return find(__k) != end(); }
1300  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
1301  _LIBCPP_HIDE_FROM_ABI bool contains(const _K2& __k) const {
1302    return find(__k) != end();
1303  }
1304#endif // _LIBCPP_STD_VER >= 20
1305
1306  _LIBCPP_HIDE_FROM_ABI iterator lower_bound(const key_type& __k) { return __tree_.lower_bound(__k); }
1307  _LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const key_type& __k) const { return __tree_.lower_bound(__k); }
1308#if _LIBCPP_STD_VER >= 14
1309  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
1310  _LIBCPP_HIDE_FROM_ABI iterator lower_bound(const _K2& __k) {
1311    return __tree_.lower_bound(__k);
1312  }
1313
1314  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
1315  _LIBCPP_HIDE_FROM_ABI const_iterator lower_bound(const _K2& __k) const {
1316    return __tree_.lower_bound(__k);
1317  }
1318#endif
1319
1320  _LIBCPP_HIDE_FROM_ABI iterator upper_bound(const key_type& __k) { return __tree_.upper_bound(__k); }
1321  _LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const key_type& __k) const { return __tree_.upper_bound(__k); }
1322#if _LIBCPP_STD_VER >= 14
1323  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
1324  _LIBCPP_HIDE_FROM_ABI iterator upper_bound(const _K2& __k) {
1325    return __tree_.upper_bound(__k);
1326  }
1327  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
1328  _LIBCPP_HIDE_FROM_ABI const_iterator upper_bound(const _K2& __k) const {
1329    return __tree_.upper_bound(__k);
1330  }
1331#endif
1332
1333  _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> equal_range(const key_type& __k) {
1334    return __tree_.__equal_range_multi(__k);
1335  }
1336  _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator> equal_range(const key_type& __k) const {
1337    return __tree_.__equal_range_multi(__k);
1338  }
1339#if _LIBCPP_STD_VER >= 14
1340  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
1341  _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> equal_range(const _K2& __k) {
1342    return __tree_.__equal_range_multi(__k);
1343  }
1344  template <typename _K2, enable_if_t<__is_transparent_v<_Compare, _K2>, int> = 0>
1345  _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator> equal_range(const _K2& __k) const {
1346    return __tree_.__equal_range_multi(__k);
1347  }
1348#endif
1349};
1350
1351#if _LIBCPP_STD_VER >= 17
1352template <class _InputIterator,
1353          class _Compare   = less<__iter_value_type<_InputIterator>>,
1354          class _Allocator = allocator<__iter_value_type<_InputIterator>>,
1355          class            = enable_if_t<__has_input_iterator_category<_InputIterator>::value, void>,
1356          class            = enable_if_t<__is_allocator<_Allocator>::value, void>,
1357          class            = enable_if_t<!__is_allocator<_Compare>::value, void>>
1358multiset(_InputIterator, _InputIterator, _Compare = _Compare(), _Allocator = _Allocator())
1359    -> multiset<__iter_value_type<_InputIterator>, _Compare, _Allocator>;
1360
1361#  if _LIBCPP_STD_VER >= 23
1362template <ranges::input_range _Range,
1363          class _Compare   = less<ranges::range_value_t<_Range>>,
1364          class _Allocator = allocator<ranges::range_value_t<_Range>>,
1365          class            = enable_if_t<__is_allocator<_Allocator>::value, void>,
1366          class            = enable_if_t<!__is_allocator<_Compare>::value, void>>
1367multiset(from_range_t, _Range&&, _Compare = _Compare(), _Allocator = _Allocator())
1368    -> multiset<ranges::range_value_t<_Range>, _Compare, _Allocator>;
1369#  endif
1370
1371template <class _Key,
1372          class _Compare   = less<_Key>,
1373          class _Allocator = allocator<_Key>,
1374          class            = enable_if_t<__is_allocator<_Allocator>::value, void>,
1375          class            = enable_if_t<!__is_allocator<_Compare>::value, void>>
1376multiset(initializer_list<_Key>,
1377         _Compare   = _Compare(),
1378         _Allocator = _Allocator()) -> multiset<_Key, _Compare, _Allocator>;
1379
1380template <class _InputIterator,
1381          class _Allocator,
1382          class = enable_if_t<__has_input_iterator_category<_InputIterator>::value, void>,
1383          class = enable_if_t<__is_allocator<_Allocator>::value, void>>
1384multiset(_InputIterator, _InputIterator, _Allocator)
1385    -> multiset<__iter_value_type<_InputIterator>, less<__iter_value_type<_InputIterator>>, _Allocator>;
1386
1387#  if _LIBCPP_STD_VER >= 23
1388template <ranges::input_range _Range, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value, void>>
1389multiset(from_range_t,
1390         _Range&&,
1391         _Allocator) -> multiset<ranges::range_value_t<_Range>, less<ranges::range_value_t<_Range>>, _Allocator>;
1392#  endif
1393
1394template <class _Key, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value, void>>
1395multiset(initializer_list<_Key>, _Allocator) -> multiset<_Key, less<_Key>, _Allocator>;
1396#endif
1397
1398#ifndef _LIBCPP_CXX03_LANG
1399
1400template <class _Key, class _Compare, class _Allocator>
1401multiset<_Key, _Compare, _Allocator>::multiset(multiset&& __s, const allocator_type& __a)
1402    : __tree_(std::move(__s.__tree_), __a) {
1403  if (__a != __s.get_allocator()) {
1404    const_iterator __e = cend();
1405    while (!__s.empty())
1406      insert(__e, std::move(__s.__tree_.remove(__s.begin())->__value_));
1407  }
1408}
1409
1410#endif // _LIBCPP_CXX03_LANG
1411
1412template <class _Key, class _Compare, class _Allocator>
1413inline _LIBCPP_HIDE_FROM_ABI bool
1414operator==(const multiset<_Key, _Compare, _Allocator>& __x, const multiset<_Key, _Compare, _Allocator>& __y) {
1415  return __x.size() == __y.size() && std::equal(__x.begin(), __x.end(), __y.begin());
1416}
1417
1418#if _LIBCPP_STD_VER <= 17
1419
1420template <class _Key, class _Compare, class _Allocator>
1421inline _LIBCPP_HIDE_FROM_ABI bool
1422operator<(const multiset<_Key, _Compare, _Allocator>& __x, const multiset<_Key, _Compare, _Allocator>& __y) {
1423  return std::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
1424}
1425
1426template <class _Key, class _Compare, class _Allocator>
1427inline _LIBCPP_HIDE_FROM_ABI bool
1428operator!=(const multiset<_Key, _Compare, _Allocator>& __x, const multiset<_Key, _Compare, _Allocator>& __y) {
1429  return !(__x == __y);
1430}
1431
1432template <class _Key, class _Compare, class _Allocator>
1433inline _LIBCPP_HIDE_FROM_ABI bool
1434operator>(const multiset<_Key, _Compare, _Allocator>& __x, const multiset<_Key, _Compare, _Allocator>& __y) {
1435  return __y < __x;
1436}
1437
1438template <class _Key, class _Compare, class _Allocator>
1439inline _LIBCPP_HIDE_FROM_ABI bool
1440operator>=(const multiset<_Key, _Compare, _Allocator>& __x, const multiset<_Key, _Compare, _Allocator>& __y) {
1441  return !(__x < __y);
1442}
1443
1444template <class _Key, class _Compare, class _Allocator>
1445inline _LIBCPP_HIDE_FROM_ABI bool
1446operator<=(const multiset<_Key, _Compare, _Allocator>& __x, const multiset<_Key, _Compare, _Allocator>& __y) {
1447  return !(__y < __x);
1448}
1449
1450#else // _LIBCPP_STD_VER <= 17
1451
1452template <class _Key, class _Allocator>
1453_LIBCPP_HIDE_FROM_ABI __synth_three_way_result<_Key>
1454operator<=>(const multiset<_Key, _Allocator>& __x, const multiset<_Key, _Allocator>& __y) {
1455  return std::lexicographical_compare_three_way(
1456      __x.begin(), __x.end(), __y.begin(), __y.end(), __synth_three_way);
1457}
1458
1459#endif // _LIBCPP_STD_VER <= 17
1460
1461template <class _Key, class _Compare, class _Allocator>
1462inline _LIBCPP_HIDE_FROM_ABI void
1463swap(multiset<_Key, _Compare, _Allocator>& __x, multiset<_Key, _Compare, _Allocator>& __y)
1464    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) {
1465  __x.swap(__y);
1466}
1467
1468#if _LIBCPP_STD_VER >= 20
1469template <class _Key, class _Compare, class _Allocator, class _Predicate>
1470inline _LIBCPP_HIDE_FROM_ABI typename multiset<_Key, _Compare, _Allocator>::size_type
1471erase_if(multiset<_Key, _Compare, _Allocator>& __c, _Predicate __pred) {
1472  return std::__libcpp_erase_if_container(__c, __pred);
1473}
1474#endif
1475
1476_LIBCPP_END_NAMESPACE_STD
1477
1478#if _LIBCPP_STD_VER >= 17
1479_LIBCPP_BEGIN_NAMESPACE_STD
1480namespace pmr {
1481template <class _KeyT, class _CompareT = std::less<_KeyT>>
1482using set _LIBCPP_AVAILABILITY_PMR = std::set<_KeyT, _CompareT, polymorphic_allocator<_KeyT>>;
1483
1484template <class _KeyT, class _CompareT = std::less<_KeyT>>
1485using multiset _LIBCPP_AVAILABILITY_PMR = std::multiset<_KeyT, _CompareT, polymorphic_allocator<_KeyT>>;
1486} // namespace pmr
1487_LIBCPP_END_NAMESPACE_STD
1488#endif
1489
1490_LIBCPP_POP_MACROS
1491
1492#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
1493#  include <concepts>
1494#  include <cstdlib>
1495#  include <functional>
1496#  include <iterator>
1497#  include <stdexcept>
1498#  include <type_traits>
1499#endif
1500
1501#endif // _LIBCPP_SET
1502