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_UNORDERED_SET
11#define _LIBCPP_UNORDERED_SET
12
13/*
14
15    unordered_set synopsis
16
17#include <initializer_list>
18
19namespace std
20{
21
22template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
23          class Alloc = allocator<Value>>
24class unordered_set
25{
26public:
27    // types
28    typedef Value                                                      key_type;
29    typedef key_type                                                   value_type;
30    typedef Hash                                                       hasher;
31    typedef Pred                                                       key_equal;
32    typedef Alloc                                                      allocator_type;
33    typedef value_type&                                                reference;
34    typedef const value_type&                                          const_reference;
35    typedef typename allocator_traits<allocator_type>::pointer         pointer;
36    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
37    typedef typename allocator_traits<allocator_type>::size_type       size_type;
38    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
39
40    typedef /unspecified/ iterator;
41    typedef /unspecified/ const_iterator;
42    typedef /unspecified/ local_iterator;
43    typedef /unspecified/ const_local_iterator;
44
45    typedef unspecified node_type unspecified;                            // C++17
46    typedef INSERT_RETURN_TYPE<iterator, node_type> insert_return_type;   // C++17
47
48    unordered_set()
49        noexcept(
50            is_nothrow_default_constructible<hasher>::value &&
51            is_nothrow_default_constructible<key_equal>::value &&
52            is_nothrow_default_constructible<allocator_type>::value);
53    explicit unordered_set(size_type n, const hasher& hf = hasher(),
54                           const key_equal& eql = key_equal(),
55                           const allocator_type& a = allocator_type());
56    template <class InputIterator>
57        unordered_set(InputIterator f, InputIterator l,
58                      size_type n = 0, const hasher& hf = hasher(),
59                      const key_equal& eql = key_equal(),
60                      const allocator_type& a = allocator_type());
61    explicit unordered_set(const allocator_type&);
62    unordered_set(const unordered_set&);
63    unordered_set(const unordered_set&, const Allocator&);
64    unordered_set(unordered_set&&)
65        noexcept(
66            is_nothrow_move_constructible<hasher>::value &&
67            is_nothrow_move_constructible<key_equal>::value &&
68            is_nothrow_move_constructible<allocator_type>::value);
69    unordered_set(unordered_set&&, const Allocator&);
70    unordered_set(initializer_list<value_type>, size_type n = 0,
71                  const hasher& hf = hasher(), const key_equal& eql = key_equal(),
72                  const allocator_type& a = allocator_type());
73    unordered_set(size_type n, const allocator_type& a); // C++14
74    unordered_set(size_type n, const hasher& hf, const allocator_type& a); // C++14
75    template <class InputIterator>
76      unordered_set(InputIterator f, InputIterator l, size_type n, const allocator_type& a); // C++14
77    template <class InputIterator>
78      unordered_set(InputIterator f, InputIterator l, size_type n,
79                    const hasher& hf,  const allocator_type& a); // C++14
80    unordered_set(initializer_list<value_type> il, size_type n, const allocator_type& a); // C++14
81    unordered_set(initializer_list<value_type> il, size_type n,
82                  const hasher& hf,  const allocator_type& a); // C++14
83    ~unordered_set();
84    unordered_set& operator=(const unordered_set&);
85    unordered_set& operator=(unordered_set&&)
86        noexcept(
87            allocator_type::propagate_on_container_move_assignment::value &&
88            is_nothrow_move_assignable<allocator_type>::value &&
89            is_nothrow_move_assignable<hasher>::value &&
90            is_nothrow_move_assignable<key_equal>::value);
91    unordered_set& operator=(initializer_list<value_type>);
92
93    allocator_type get_allocator() const noexcept;
94
95    bool      empty() const noexcept;
96    size_type size() const noexcept;
97    size_type max_size() const noexcept;
98
99    iterator       begin() noexcept;
100    iterator       end() noexcept;
101    const_iterator begin()  const noexcept;
102    const_iterator end()    const noexcept;
103    const_iterator cbegin() const noexcept;
104    const_iterator cend()   const noexcept;
105
106    template <class... Args>
107        pair<iterator, bool> emplace(Args&&... args);
108    template <class... Args>
109        iterator emplace_hint(const_iterator position, Args&&... args);
110    pair<iterator, bool> insert(const value_type& obj);
111    pair<iterator, bool> insert(value_type&& obj);
112    iterator insert(const_iterator hint, const value_type& obj);
113    iterator insert(const_iterator hint, value_type&& obj);
114    template <class InputIterator>
115        void insert(InputIterator first, InputIterator last);
116    void insert(initializer_list<value_type>);
117
118    node_type extract(const_iterator position);                       // C++17
119    node_type extract(const key_type& x);                             // C++17
120    insert_return_type insert(node_type&& nh);                        // C++17
121    iterator           insert(const_iterator hint, node_type&& nh);   // C++17
122
123    iterator erase(const_iterator position);
124    iterator erase(iterator position);  // C++14
125    size_type erase(const key_type& k);
126    iterator erase(const_iterator first, const_iterator last);
127    void clear() noexcept;
128
129    template<class H2, class P2>
130      void merge(unordered_set<Key, H2, P2, Allocator>& source);         // C++17
131    template<class H2, class P2>
132      void merge(unordered_set<Key, H2, P2, Allocator>&& source);        // C++17
133    template<class H2, class P2>
134      void merge(unordered_multiset<Key, H2, P2, Allocator>& source);    // C++17
135    template<class H2, class P2>
136      void merge(unordered_multiset<Key, H2, P2, Allocator>&& source);   // C++17
137
138    void swap(unordered_set&)
139       noexcept(allocator_traits<Allocator>::is_always_equal::value &&
140                 noexcept(swap(declval<hasher&>(), declval<hasher&>())) &&
141                 noexcept(swap(declval<key_equal&>(), declval<key_equal&>()))); // C++17
142
143    hasher hash_function() const;
144    key_equal key_eq() const;
145
146    iterator       find(const key_type& k);
147    const_iterator find(const key_type& k) const;
148    template<typename K>
149        iterator find(const K& x);              // C++20
150    template<typename K>
151        const_iterator find(const K& x) const;  // C++20
152    size_type count(const key_type& k) const;
153    template<typename K>
154        size_type count(const K& k) const; // C++20
155    bool contains(const key_type& k) const; // C++20
156    template<typename K>
157        bool contains(const K& k) const; // C++20
158    pair<iterator, iterator>             equal_range(const key_type& k);
159    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
160    template<typename K>
161        pair<iterator, iterator>             equal_range(const K& k); // C++20
162    template<typename K>
163        pair<const_iterator, const_iterator> equal_range(const K& k) const; // C++20
164
165    size_type bucket_count() const noexcept;
166    size_type max_bucket_count() const noexcept;
167
168    size_type bucket_size(size_type n) const;
169    size_type bucket(const key_type& k) const;
170
171    local_iterator       begin(size_type n);
172    local_iterator       end(size_type n);
173    const_local_iterator begin(size_type n) const;
174    const_local_iterator end(size_type n) const;
175    const_local_iterator cbegin(size_type n) const;
176    const_local_iterator cend(size_type n) const;
177
178    float load_factor() const noexcept;
179    float max_load_factor() const noexcept;
180    void max_load_factor(float z);
181    void rehash(size_type n);
182    void reserve(size_type n);
183};
184
185template<class InputIterator,
186    class Hash = hash<typename iterator_traits<InputIterator>::value_type>,
187    class Pred = equal_to<typename iterator_traits<InputIterator>::value_type>,
188    class Allocator = allocator<typename iterator_traits<InputIterator>::value_type>>
189unordered_set(InputIterator, InputIterator, typename see below::size_type = see below,
190    Hash = Hash(), Pred = Pred(), Allocator = Allocator())
191  -> unordered_set<typename iterator_traits<InputIterator>::value_type,
192        Hash, Pred, Allocator>; // C++17
193
194template<class T, class Hash = hash<T>,
195          class Pred = equal_to<T>, class Allocator = allocator<T>>
196unordered_set(initializer_list<T>, typename see below::size_type = see below,
197    Hash = Hash(), Pred = Pred(), Allocator = Allocator())
198  -> unordered_set<T, Hash, Pred, Allocator>; // C++17
199
200template<class InputIterator,  class Allocator>
201unordered_set(InputIterator, InputIterator, typename see below::size_type, Allocator)
202  -> unordered_set<typename iterator_traits<InputIterator>::value_type,
203        hash<typename iterator_traits<InputIterator>::value_type>,
204        equal_to<typename iterator_traits<InputIterator>::value_type>,
205        Allocator>; // C++17
206
207template<class InputIterator, class Hash, class Allocator>
208unordered_set(InputIterator, InputIterator, typename see below::size_type,
209    Hash, Allocator)
210  -> unordered_set<typename iterator_traits<InputIterator>::value_type, Hash,
211        equal_to<typename iterator_traits<InputIterator>::value_type>,
212        Allocator>; // C++17
213
214template<class T, class Allocator>
215unordered_set(initializer_list<T>, typename see below::size_type, Allocator)
216  -> unordered_set<T, hash<T>, equal_to<T>, Allocator>; // C++17
217
218template<class T, class Hash, class Allocator>
219unordered_set(initializer_list<T>, typename see below::size_type, Hash, Allocator)
220  -> unordered_set<T, Hash, equal_to<T>, Allocator>; // C++17
221
222template <class Value, class Hash, class Pred, class Alloc>
223    void swap(unordered_set<Value, Hash, Pred, Alloc>& x,
224              unordered_set<Value, Hash, Pred, Alloc>& y)
225              noexcept(noexcept(x.swap(y)));
226
227template <class Value, class Hash, class Pred, class Alloc>
228    bool
229    operator==(const unordered_set<Value, Hash, Pred, Alloc>& x,
230               const unordered_set<Value, Hash, Pred, Alloc>& y);
231
232template <class Value, class Hash, class Pred, class Alloc>
233    bool
234    operator!=(const unordered_set<Value, Hash, Pred, Alloc>& x,
235               const unordered_set<Value, Hash, Pred, Alloc>& y);
236
237template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
238          class Alloc = allocator<Value>>
239class unordered_multiset
240{
241public:
242    // types
243    typedef Value                                                      key_type;
244    typedef key_type                                                   value_type;
245    typedef Hash                                                       hasher;
246    typedef Pred                                                       key_equal;
247    typedef Alloc                                                      allocator_type;
248    typedef value_type&                                                reference;
249    typedef const value_type&                                          const_reference;
250    typedef typename allocator_traits<allocator_type>::pointer         pointer;
251    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
252    typedef typename allocator_traits<allocator_type>::size_type       size_type;
253    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
254
255    typedef /unspecified/ iterator;
256    typedef /unspecified/ const_iterator;
257    typedef /unspecified/ local_iterator;
258    typedef /unspecified/ const_local_iterator;
259
260    typedef unspecified node_type unspecified;   // C++17
261
262    unordered_multiset()
263        noexcept(
264            is_nothrow_default_constructible<hasher>::value &&
265            is_nothrow_default_constructible<key_equal>::value &&
266            is_nothrow_default_constructible<allocator_type>::value);
267    explicit unordered_multiset(size_type n, const hasher& hf = hasher(),
268                           const key_equal& eql = key_equal(),
269                           const allocator_type& a = allocator_type());
270    template <class InputIterator>
271        unordered_multiset(InputIterator f, InputIterator l,
272                      size_type n = 0, const hasher& hf = hasher(),
273                      const key_equal& eql = key_equal(),
274                      const allocator_type& a = allocator_type());
275    explicit unordered_multiset(const allocator_type&);
276    unordered_multiset(const unordered_multiset&);
277    unordered_multiset(const unordered_multiset&, const Allocator&);
278    unordered_multiset(unordered_multiset&&)
279        noexcept(
280            is_nothrow_move_constructible<hasher>::value &&
281            is_nothrow_move_constructible<key_equal>::value &&
282            is_nothrow_move_constructible<allocator_type>::value);
283    unordered_multiset(unordered_multiset&&, const Allocator&);
284    unordered_multiset(initializer_list<value_type>, size_type n = /see below/,
285                  const hasher& hf = hasher(), const key_equal& eql = key_equal(),
286                  const allocator_type& a = allocator_type());
287    unordered_multiset(size_type n, const allocator_type& a); // C++14
288    unordered_multiset(size_type n, const hasher& hf, const allocator_type& a); // C++14
289    template <class InputIterator>
290      unordered_multiset(InputIterator f, InputIterator l, size_type n, const allocator_type& a); // C++14
291    template <class InputIterator>
292      unordered_multiset(InputIterator f, InputIterator l, size_type n,
293                         const hasher& hf, const allocator_type& a); // C++14
294    unordered_multiset(initializer_list<value_type> il, size_type n, const allocator_type& a); // C++14
295    unordered_multiset(initializer_list<value_type> il, size_type n,
296                       const hasher& hf,  const allocator_type& a); // C++14
297    ~unordered_multiset();
298    unordered_multiset& operator=(const unordered_multiset&);
299    unordered_multiset& operator=(unordered_multiset&&)
300        noexcept(
301            allocator_type::propagate_on_container_move_assignment::value &&
302            is_nothrow_move_assignable<allocator_type>::value &&
303            is_nothrow_move_assignable<hasher>::value &&
304            is_nothrow_move_assignable<key_equal>::value);
305    unordered_multiset& operator=(initializer_list<value_type>);
306
307    allocator_type get_allocator() const noexcept;
308
309    bool      empty() const noexcept;
310    size_type size() const noexcept;
311    size_type max_size() const noexcept;
312
313    iterator       begin() noexcept;
314    iterator       end() noexcept;
315    const_iterator begin()  const noexcept;
316    const_iterator end()    const noexcept;
317    const_iterator cbegin() const noexcept;
318    const_iterator cend()   const noexcept;
319
320    template <class... Args>
321        iterator emplace(Args&&... args);
322    template <class... Args>
323        iterator emplace_hint(const_iterator position, Args&&... args);
324    iterator insert(const value_type& obj);
325    iterator insert(value_type&& obj);
326    iterator insert(const_iterator hint, const value_type& obj);
327    iterator insert(const_iterator hint, value_type&& obj);
328    template <class InputIterator>
329        void insert(InputIterator first, InputIterator last);
330    void insert(initializer_list<value_type>);
331
332    node_type extract(const_iterator position);             // C++17
333    node_type extract(const key_type& x);                   // C++17
334    iterator insert(node_type&& nh);                        // C++17
335    iterator insert(const_iterator hint, node_type&& nh);   // C++17
336
337    iterator erase(const_iterator position);
338    iterator erase(iterator position);  // C++14
339    size_type erase(const key_type& k);
340    iterator erase(const_iterator first, const_iterator last);
341    void clear() noexcept;
342
343    template<class H2, class P2>
344      void merge(unordered_multiset<Key, H2, P2, Allocator>& source);    // C++17
345    template<class H2, class P2>
346      void merge(unordered_multiset<Key, H2, P2, Allocator>&& source);   // C++17
347    template<class H2, class P2>
348      void merge(unordered_set<Key, H2, P2, Allocator>& source);         // C++17
349    template<class H2, class P2>
350      void merge(unordered_set<Key, H2, P2, Allocator>&& source);        // C++17
351
352    void swap(unordered_multiset&)
353       noexcept(allocator_traits<Allocator>::is_always_equal::value &&
354                 noexcept(swap(declval<hasher&>(), declval<hasher&>())) &&
355                 noexcept(swap(declval<key_equal&>(), declval<key_equal&>()))); // C++17
356
357    hasher hash_function() const;
358    key_equal key_eq() const;
359
360    iterator       find(const key_type& k);
361    const_iterator find(const key_type& k) const;
362    template<typename K>
363        iterator find(const K& x);              // C++20
364    template<typename K>
365        const_iterator find(const K& x) const;  // C++20
366    size_type count(const key_type& k) const;
367    template<typename K>
368        size_type count(const K& k) const; // C++20
369    bool contains(const key_type& k) const; // C++20
370    template<typename K>
371        bool contains(const K& k) const; // C++20
372    pair<iterator, iterator>             equal_range(const key_type& k);
373    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
374    template<typename K>
375        pair<iterator, iterator>             equal_range(const K& k); // C++20
376    template<typename K>
377        pair<const_iterator, const_iterator> equal_range(const K& k) const; // C++20
378
379    size_type bucket_count() const noexcept;
380    size_type max_bucket_count() const noexcept;
381
382    size_type bucket_size(size_type n) const;
383    size_type bucket(const key_type& k) const;
384
385    local_iterator       begin(size_type n);
386    local_iterator       end(size_type n);
387    const_local_iterator begin(size_type n) const;
388    const_local_iterator end(size_type n) const;
389    const_local_iterator cbegin(size_type n) const;
390    const_local_iterator cend(size_type n) const;
391
392    float load_factor() const noexcept;
393    float max_load_factor() const noexcept;
394    void max_load_factor(float z);
395    void rehash(size_type n);
396    void reserve(size_type n);
397};
398
399template<class InputIterator,
400    class Hash = hash<typename iterator_traits<InputIterator>::value_type>,
401    class Pred = equal_to<typename iterator_traits<InputIterator>::value_type>,
402    class Allocator = allocator<typename iterator_traits<InputIterator>::value_type>>
403unordered_multiset(InputIterator, InputIterator, see below::size_type = see below,
404    Hash = Hash(), Pred = Pred(), Allocator = Allocator())
405  -> unordered_multiset<typename iterator_traits<InputIterator>::value_type,
406        Hash, Pred, Allocator>; // C++17
407
408template<class T, class Hash = hash<T>,
409          class Pred = equal_to<T>, class Allocator = allocator<T>>
410unordered_multiset(initializer_list<T>, typename see below::size_type = see below,
411    Hash = Hash(), Pred = Pred(), Allocator = Allocator())
412  -> unordered_multiset<T, Hash, Pred, Allocator>; // C++17
413
414template<class InputIterator,  class Allocator>
415unordered_multiset(InputIterator, InputIterator, typename see below::size_type, Allocator)
416  -> unordered_multiset<typename iterator_traits<InputIterator>::value_type,
417        hash<typename iterator_traits<InputIterator>::value_type>,
418        equal_to<typename iterator_traits<InputIterator>::value_type>,
419        Allocator>; // C++17
420
421template<class InputIterator,  class Hash, class Allocator>
422unordered_multiset(InputIterator, InputIterator, typename see below::size_type,
423    Hash, Allocator)
424  -> unordered_multiset<typename iterator_traits<InputIterator>::value_type, Hash,
425        equal_to<typename iterator_traits<InputIterator>::value_type>, Allocator>; // C++17
426
427template<class T, class Allocator>
428unordered_multiset(initializer_list<T>, typename see below::size_type, Allocator)
429  -> unordered_multiset<T, hash<T>, equal_to<T>, Allocator>; // C++17
430
431template<class T, class Hash, class Allocator>
432unordered_multiset(initializer_list<T>, typename see below::size_type, Hash, Allocator)
433  -> unordered_multiset<T, Hash, equal_to<T>, Allocator>; // C++17
434
435template <class Value, class Hash, class Pred, class Alloc>
436    void swap(unordered_multiset<Value, Hash, Pred, Alloc>& x,
437              unordered_multiset<Value, Hash, Pred, Alloc>& y)
438              noexcept(noexcept(x.swap(y)));
439
440template <class K, class T, class H, class P, class A, class Predicate>
441    typename unordered_set<K, T, H, P, A>::size_type
442    erase_if(unordered_set<K, T, H, P, A>& c, Predicate pred);       // C++20
443
444template <class K, class T, class H, class P, class A, class Predicate>
445    typename unordered_multiset<K, T, H, P, A>::size_type
446    erase_if(unordered_multiset<K, T, H, P, A>& c, Predicate pred);  // C++20
447
448
449template <class Value, class Hash, class Pred, class Alloc>
450    bool
451    operator==(const unordered_multiset<Value, Hash, Pred, Alloc>& x,
452               const unordered_multiset<Value, Hash, Pred, Alloc>& y);
453
454template <class Value, class Hash, class Pred, class Alloc>
455    bool
456    operator!=(const unordered_multiset<Value, Hash, Pred, Alloc>& x,
457               const unordered_multiset<Value, Hash, Pred, Alloc>& y);
458}  // std
459
460*/
461
462#include <__algorithm/is_permutation.h>
463#include <__assert>
464#include <__config>
465#include <__debug>
466#include <__functional/is_transparent.h>
467#include <__hash_table>
468#include <__memory/addressof.h>
469#include <__node_handle>
470#include <__utility/forward.h>
471#include <compare>
472#include <functional>
473#include <iterator> // __libcpp_erase_if_container
474#include <version>
475
476#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
477#  pragma GCC system_header
478#endif
479
480_LIBCPP_BEGIN_NAMESPACE_STD
481
482template <class _Value, class _Hash, class _Pred, class _Alloc>
483class unordered_multiset;
484
485template <class _Value, class _Hash = hash<_Value>, class _Pred = equal_to<_Value>,
486          class _Alloc = allocator<_Value> >
487class _LIBCPP_TEMPLATE_VIS unordered_set
488{
489public:
490    // types
491    typedef _Value                                                     key_type;
492    typedef key_type                                                   value_type;
493    typedef __identity_t<_Hash>                                        hasher;
494    typedef __identity_t<_Pred>                                        key_equal;
495    typedef __identity_t<_Alloc>                                       allocator_type;
496    typedef value_type&                                                reference;
497    typedef const value_type&                                          const_reference;
498    static_assert((is_same<value_type, typename allocator_type::value_type>::value),
499                  "Invalid allocator::value_type");
500
501private:
502    typedef __hash_table<value_type, hasher, key_equal, allocator_type> __table;
503
504    __table __table_;
505
506public:
507    typedef typename __table::pointer         pointer;
508    typedef typename __table::const_pointer   const_pointer;
509    typedef typename __table::size_type       size_type;
510    typedef typename __table::difference_type difference_type;
511
512    typedef typename __table::const_iterator       iterator;
513    typedef typename __table::const_iterator       const_iterator;
514    typedef typename __table::const_local_iterator local_iterator;
515    typedef typename __table::const_local_iterator const_local_iterator;
516
517#if _LIBCPP_STD_VER > 14
518    typedef __set_node_handle<typename __table::__node, allocator_type> node_type;
519    typedef __insert_return_type<iterator, node_type> insert_return_type;
520#endif
521
522    template <class _Value2, class _Hash2, class _Pred2, class _Alloc2>
523        friend class _LIBCPP_TEMPLATE_VIS unordered_set;
524    template <class _Value2, class _Hash2, class _Pred2, class _Alloc2>
525        friend class _LIBCPP_TEMPLATE_VIS unordered_multiset;
526
527    _LIBCPP_INLINE_VISIBILITY
528    unordered_set()
529        _NOEXCEPT_(is_nothrow_default_constructible<__table>::value)
530    {
531        _VSTD::__debug_db_insert_c(this);
532    }
533    explicit unordered_set(size_type __n, const hasher& __hf = hasher(),
534                           const key_equal& __eql = key_equal());
535#if _LIBCPP_STD_VER > 11
536    inline _LIBCPP_INLINE_VISIBILITY
537    unordered_set(size_type __n, const allocator_type& __a)
538        : unordered_set(__n, hasher(), key_equal(), __a) {}
539    inline _LIBCPP_INLINE_VISIBILITY
540    unordered_set(size_type __n, const hasher& __hf, const allocator_type& __a)
541        : unordered_set(__n, __hf, key_equal(), __a) {}
542#endif
543    unordered_set(size_type __n, const hasher& __hf, const key_equal& __eql,
544                  const allocator_type& __a);
545    template <class _InputIterator>
546        unordered_set(_InputIterator __first, _InputIterator __last);
547    template <class _InputIterator>
548        unordered_set(_InputIterator __first, _InputIterator __last,
549                      size_type __n, const hasher& __hf = hasher(),
550                      const key_equal& __eql = key_equal());
551    template <class _InputIterator>
552        unordered_set(_InputIterator __first, _InputIterator __last,
553                      size_type __n, const hasher& __hf, const key_equal& __eql,
554                      const allocator_type& __a);
555#if _LIBCPP_STD_VER > 11
556    template <class _InputIterator>
557    inline _LIBCPP_INLINE_VISIBILITY
558        unordered_set(_InputIterator __first, _InputIterator __last,
559                    size_type __n, const allocator_type& __a)
560            : unordered_set(__first, __last, __n, hasher(), key_equal(), __a) {}
561    template <class _InputIterator>
562        unordered_set(_InputIterator __first, _InputIterator __last,
563                      size_type __n, const hasher& __hf, const allocator_type& __a)
564            : unordered_set(__first, __last, __n, __hf, key_equal(), __a) {}
565#endif
566    _LIBCPP_INLINE_VISIBILITY
567    explicit unordered_set(const allocator_type& __a);
568    unordered_set(const unordered_set& __u);
569    unordered_set(const unordered_set& __u, const allocator_type& __a);
570#ifndef _LIBCPP_CXX03_LANG
571    _LIBCPP_INLINE_VISIBILITY
572    unordered_set(unordered_set&& __u)
573        _NOEXCEPT_(is_nothrow_move_constructible<__table>::value);
574    unordered_set(unordered_set&& __u, const allocator_type& __a);
575    unordered_set(initializer_list<value_type> __il);
576    unordered_set(initializer_list<value_type> __il, size_type __n,
577                  const hasher& __hf = hasher(),
578                  const key_equal& __eql = key_equal());
579    unordered_set(initializer_list<value_type> __il, size_type __n,
580                  const hasher& __hf, const key_equal& __eql,
581                  const allocator_type& __a);
582#if _LIBCPP_STD_VER > 11
583    inline _LIBCPP_INLINE_VISIBILITY
584    unordered_set(initializer_list<value_type> __il, size_type __n,
585                                                      const allocator_type& __a)
586        : unordered_set(__il, __n, hasher(), key_equal(), __a) {}
587    inline _LIBCPP_INLINE_VISIBILITY
588    unordered_set(initializer_list<value_type> __il, size_type __n,
589                                  const hasher& __hf, const allocator_type& __a)
590        : unordered_set(__il, __n, __hf, key_equal(), __a) {}
591#endif
592#endif // _LIBCPP_CXX03_LANG
593    _LIBCPP_INLINE_VISIBILITY
594    ~unordered_set() {
595        static_assert(sizeof(__diagnose_unordered_container_requirements<_Value, _Hash, _Pred>(0)), "");
596    }
597
598    _LIBCPP_INLINE_VISIBILITY
599    unordered_set& operator=(const unordered_set& __u)
600    {
601        __table_ = __u.__table_;
602        return *this;
603    }
604#ifndef _LIBCPP_CXX03_LANG
605    _LIBCPP_INLINE_VISIBILITY
606    unordered_set& operator=(unordered_set&& __u)
607        _NOEXCEPT_(is_nothrow_move_assignable<__table>::value);
608    _LIBCPP_INLINE_VISIBILITY
609    unordered_set& operator=(initializer_list<value_type> __il);
610#endif // _LIBCPP_CXX03_LANG
611
612    _LIBCPP_INLINE_VISIBILITY
613    allocator_type get_allocator() const _NOEXCEPT
614        {return allocator_type(__table_.__node_alloc());}
615
616    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
617    bool      empty() const _NOEXCEPT {return __table_.size() == 0;}
618    _LIBCPP_INLINE_VISIBILITY
619    size_type size() const _NOEXCEPT  {return __table_.size();}
620    _LIBCPP_INLINE_VISIBILITY
621    size_type max_size() const _NOEXCEPT {return __table_.max_size();}
622
623    _LIBCPP_INLINE_VISIBILITY
624    iterator       begin() _NOEXCEPT        {return __table_.begin();}
625    _LIBCPP_INLINE_VISIBILITY
626    iterator       end() _NOEXCEPT          {return __table_.end();}
627    _LIBCPP_INLINE_VISIBILITY
628    const_iterator begin()  const _NOEXCEPT {return __table_.begin();}
629    _LIBCPP_INLINE_VISIBILITY
630    const_iterator end()    const _NOEXCEPT {return __table_.end();}
631    _LIBCPP_INLINE_VISIBILITY
632    const_iterator cbegin() const _NOEXCEPT {return __table_.begin();}
633    _LIBCPP_INLINE_VISIBILITY
634    const_iterator cend()   const _NOEXCEPT {return __table_.end();}
635
636#ifndef _LIBCPP_CXX03_LANG
637    template <class... _Args>
638        _LIBCPP_INLINE_VISIBILITY
639        pair<iterator, bool> emplace(_Args&&... __args)
640            {return __table_.__emplace_unique(_VSTD::forward<_Args>(__args)...);}
641    template <class... _Args>
642        _LIBCPP_INLINE_VISIBILITY
643#if _LIBCPP_DEBUG_LEVEL == 2
644        iterator emplace_hint(const_iterator __p, _Args&&... __args)
645        {
646            _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(_VSTD::addressof(__p)) == this,
647                "unordered_set::emplace_hint(const_iterator, args...) called with an iterator not"
648                " referring to this unordered_set");
649            return __table_.__emplace_unique(_VSTD::forward<_Args>(__args)...).first;
650        }
651#else
652        iterator emplace_hint(const_iterator, _Args&&... __args)
653            {return __table_.__emplace_unique(_VSTD::forward<_Args>(__args)...).first;}
654#endif
655
656    _LIBCPP_INLINE_VISIBILITY
657    pair<iterator, bool> insert(value_type&& __x)
658        {return __table_.__insert_unique(_VSTD::move(__x));}
659    _LIBCPP_INLINE_VISIBILITY
660#if _LIBCPP_DEBUG_LEVEL == 2
661    iterator insert(const_iterator __p, value_type&& __x)
662        {
663            _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(_VSTD::addressof(__p)) == this,
664                "unordered_set::insert(const_iterator, value_type&&) called with an iterator not"
665                " referring to this unordered_set");
666            return insert(_VSTD::move(__x)).first;
667        }
668#else
669    iterator insert(const_iterator, value_type&& __x)
670        {return insert(_VSTD::move(__x)).first;}
671#endif
672    _LIBCPP_INLINE_VISIBILITY
673    void insert(initializer_list<value_type> __il)
674        {insert(__il.begin(), __il.end());}
675#endif // _LIBCPP_CXX03_LANG
676    _LIBCPP_INLINE_VISIBILITY
677    pair<iterator, bool> insert(const value_type& __x)
678        {return __table_.__insert_unique(__x);}
679
680    _LIBCPP_INLINE_VISIBILITY
681#if _LIBCPP_DEBUG_LEVEL == 2
682    iterator insert(const_iterator __p, const value_type& __x)
683        {
684            _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(_VSTD::addressof(__p)) == this,
685                "unordered_set::insert(const_iterator, const value_type&) called with an iterator not"
686                " referring to this unordered_set");
687            return insert(__x).first;
688        }
689#else
690    iterator insert(const_iterator, const value_type& __x)
691        {return insert(__x).first;}
692#endif
693    template <class _InputIterator>
694        _LIBCPP_INLINE_VISIBILITY
695        void insert(_InputIterator __first, _InputIterator __last);
696
697    _LIBCPP_INLINE_VISIBILITY
698    iterator erase(const_iterator __p) {return __table_.erase(__p);}
699    _LIBCPP_INLINE_VISIBILITY
700    size_type erase(const key_type& __k) {return __table_.__erase_unique(__k);}
701    _LIBCPP_INLINE_VISIBILITY
702    iterator erase(const_iterator __first, const_iterator __last)
703        {return __table_.erase(__first, __last);}
704    _LIBCPP_INLINE_VISIBILITY
705    void clear() _NOEXCEPT {__table_.clear();}
706
707#if _LIBCPP_STD_VER > 14
708    _LIBCPP_INLINE_VISIBILITY
709    insert_return_type insert(node_type&& __nh)
710    {
711        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
712            "node_type with incompatible allocator passed to unordered_set::insert()");
713        return __table_.template __node_handle_insert_unique<
714            node_type, insert_return_type>(_VSTD::move(__nh));
715    }
716    _LIBCPP_INLINE_VISIBILITY
717    iterator insert(const_iterator __h, node_type&& __nh)
718    {
719        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
720            "node_type with incompatible allocator passed to unordered_set::insert()");
721        return __table_.template __node_handle_insert_unique<node_type>(
722            __h, _VSTD::move(__nh));
723    }
724    _LIBCPP_INLINE_VISIBILITY
725    node_type extract(key_type const& __key)
726    {
727        return __table_.template __node_handle_extract<node_type>(__key);
728    }
729    _LIBCPP_INLINE_VISIBILITY
730    node_type extract(const_iterator __it)
731    {
732        return __table_.template __node_handle_extract<node_type>(__it);
733    }
734
735    template<class _H2, class _P2>
736    _LIBCPP_INLINE_VISIBILITY
737    void merge(unordered_set<key_type, _H2, _P2, allocator_type>& __source)
738    {
739        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
740                       "merging container with incompatible allocator");
741        __table_.__node_handle_merge_unique(__source.__table_);
742    }
743    template<class _H2, class _P2>
744    _LIBCPP_INLINE_VISIBILITY
745    void merge(unordered_set<key_type, _H2, _P2, allocator_type>&& __source)
746    {
747        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
748                       "merging container with incompatible allocator");
749        __table_.__node_handle_merge_unique(__source.__table_);
750    }
751    template<class _H2, class _P2>
752    _LIBCPP_INLINE_VISIBILITY
753    void merge(unordered_multiset<key_type, _H2, _P2, allocator_type>& __source)
754    {
755        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
756                       "merging container with incompatible allocator");
757        __table_.__node_handle_merge_unique(__source.__table_);
758    }
759    template<class _H2, class _P2>
760    _LIBCPP_INLINE_VISIBILITY
761    void merge(unordered_multiset<key_type, _H2, _P2, allocator_type>&& __source)
762    {
763        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
764                       "merging container with incompatible allocator");
765        __table_.__node_handle_merge_unique(__source.__table_);
766    }
767#endif
768
769    _LIBCPP_INLINE_VISIBILITY
770    void swap(unordered_set& __u)
771        _NOEXCEPT_(__is_nothrow_swappable<__table>::value)
772        {__table_.swap(__u.__table_);}
773
774    _LIBCPP_INLINE_VISIBILITY
775    hasher hash_function() const {return __table_.hash_function();}
776    _LIBCPP_INLINE_VISIBILITY
777    key_equal key_eq() const {return __table_.key_eq();}
778
779    _LIBCPP_INLINE_VISIBILITY
780    iterator       find(const key_type& __k)       {return __table_.find(__k);}
781    _LIBCPP_INLINE_VISIBILITY
782    const_iterator find(const key_type& __k) const {return __table_.find(__k);}
783#if _LIBCPP_STD_VER > 17
784    template <class _K2, enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
785    _LIBCPP_INLINE_VISIBILITY
786    iterator       find(const _K2& __k)            {return __table_.find(__k);}
787    template <class _K2, enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
788    _LIBCPP_INLINE_VISIBILITY
789    const_iterator find(const _K2& __k) const      {return __table_.find(__k);}
790#endif // _LIBCPP_STD_VER > 17
791
792    _LIBCPP_INLINE_VISIBILITY
793    size_type count(const key_type& __k) const {return __table_.__count_unique(__k);}
794#if _LIBCPP_STD_VER > 17
795    template <class _K2, enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
796    _LIBCPP_INLINE_VISIBILITY
797    size_type count(const _K2& __k) const      {return __table_.__count_unique(__k);}
798#endif // _LIBCPP_STD_VER > 17
799
800#if _LIBCPP_STD_VER > 17
801    _LIBCPP_INLINE_VISIBILITY
802    bool contains(const key_type& __k) const {return find(__k) != end();}
803
804    template <class _K2, enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
805    _LIBCPP_INLINE_VISIBILITY
806    bool contains(const _K2& __k) const      {return find(__k) != end();}
807#endif // _LIBCPP_STD_VER > 17
808
809    _LIBCPP_INLINE_VISIBILITY
810    pair<iterator, iterator>             equal_range(const key_type& __k)
811        {return __table_.__equal_range_unique(__k);}
812    _LIBCPP_INLINE_VISIBILITY
813    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
814        {return __table_.__equal_range_unique(__k);}
815#if _LIBCPP_STD_VER > 17
816    template <class _K2, enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
817    _LIBCPP_INLINE_VISIBILITY
818    pair<iterator, iterator>             equal_range(const _K2& __k)
819        {return __table_.__equal_range_unique(__k);}
820    template <class _K2, enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
821    _LIBCPP_INLINE_VISIBILITY
822    pair<const_iterator, const_iterator> equal_range(const _K2& __k) const
823        {return __table_.__equal_range_unique(__k);}
824#endif // _LIBCPP_STD_VER > 17
825
826    _LIBCPP_INLINE_VISIBILITY
827    size_type bucket_count() const _NOEXCEPT {return __table_.bucket_count();}
828    _LIBCPP_INLINE_VISIBILITY
829    size_type max_bucket_count() const _NOEXCEPT {return __table_.max_bucket_count();}
830
831    _LIBCPP_INLINE_VISIBILITY
832    size_type bucket_size(size_type __n) const {return __table_.bucket_size(__n);}
833    _LIBCPP_INLINE_VISIBILITY
834    size_type bucket(const key_type& __k) const {return __table_.bucket(__k);}
835
836    _LIBCPP_INLINE_VISIBILITY
837    local_iterator       begin(size_type __n)        {return __table_.begin(__n);}
838    _LIBCPP_INLINE_VISIBILITY
839    local_iterator       end(size_type __n)          {return __table_.end(__n);}
840    _LIBCPP_INLINE_VISIBILITY
841    const_local_iterator begin(size_type __n) const  {return __table_.cbegin(__n);}
842    _LIBCPP_INLINE_VISIBILITY
843    const_local_iterator end(size_type __n) const    {return __table_.cend(__n);}
844    _LIBCPP_INLINE_VISIBILITY
845    const_local_iterator cbegin(size_type __n) const {return __table_.cbegin(__n);}
846    _LIBCPP_INLINE_VISIBILITY
847    const_local_iterator cend(size_type __n) const   {return __table_.cend(__n);}
848
849    _LIBCPP_INLINE_VISIBILITY
850    float load_factor() const _NOEXCEPT {return __table_.load_factor();}
851    _LIBCPP_INLINE_VISIBILITY
852    float max_load_factor() const _NOEXCEPT {return __table_.max_load_factor();}
853    _LIBCPP_INLINE_VISIBILITY
854    void max_load_factor(float __mlf) {__table_.max_load_factor(__mlf);}
855    _LIBCPP_INLINE_VISIBILITY
856    void rehash(size_type __n) {__table_.rehash(__n);}
857    _LIBCPP_INLINE_VISIBILITY
858    void reserve(size_type __n) {__table_.reserve(__n);}
859
860#if _LIBCPP_DEBUG_LEVEL == 2
861
862    bool __dereferenceable(const const_iterator* __i) const
863        {return __table_.__dereferenceable(__i);}
864    bool __decrementable(const const_iterator* __i) const
865        {return __table_.__decrementable(__i);}
866    bool __addable(const const_iterator* __i, ptrdiff_t __n) const
867        {return __table_.__addable(__i, __n);}
868    bool __subscriptable(const const_iterator* __i, ptrdiff_t __n) const
869        {return __table_.__addable(__i, __n);}
870
871#endif // _LIBCPP_DEBUG_LEVEL == 2
872
873};
874
875#if _LIBCPP_STD_VER >= 17
876template<class _InputIterator,
877         class _Hash = hash<__iter_value_type<_InputIterator>>,
878         class _Pred = equal_to<__iter_value_type<_InputIterator>>,
879         class _Allocator = allocator<__iter_value_type<_InputIterator>>,
880         class = enable_if_t<__is_cpp17_input_iterator<_InputIterator>::value>,
881         class = enable_if_t<!__is_allocator<_Hash>::value>,
882         class = enable_if_t<!is_integral<_Hash>::value>,
883         class = enable_if_t<!__is_allocator<_Pred>::value>,
884         class = enable_if_t<__is_allocator<_Allocator>::value>>
885unordered_set(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type = 0,
886              _Hash = _Hash(), _Pred = _Pred(), _Allocator = _Allocator())
887  -> unordered_set<__iter_value_type<_InputIterator>, _Hash, _Pred, _Allocator>;
888
889template<class _Tp, class _Hash = hash<_Tp>,
890         class _Pred = equal_to<_Tp>,
891         class _Allocator = allocator<_Tp>,
892         class = enable_if_t<!__is_allocator<_Hash>::value>,
893         class = enable_if_t<!is_integral<_Hash>::value>,
894         class = enable_if_t<!__is_allocator<_Pred>::value>,
895         class = enable_if_t<__is_allocator<_Allocator>::value>>
896unordered_set(initializer_list<_Tp>, typename allocator_traits<_Allocator>::size_type = 0,
897              _Hash = _Hash(), _Pred = _Pred(), _Allocator = _Allocator())
898  -> unordered_set<_Tp, _Hash, _Pred, _Allocator>;
899
900template<class _InputIterator, class _Allocator,
901         class = enable_if_t<__is_cpp17_input_iterator<_InputIterator>::value>,
902         class = enable_if_t<__is_allocator<_Allocator>::value>>
903unordered_set(_InputIterator, _InputIterator,
904              typename allocator_traits<_Allocator>::size_type, _Allocator)
905  -> unordered_set<__iter_value_type<_InputIterator>,
906                   hash<__iter_value_type<_InputIterator>>,
907                   equal_to<__iter_value_type<_InputIterator>>,
908                   _Allocator>;
909
910template<class _InputIterator, class _Hash, class _Allocator,
911         class = enable_if_t<__is_cpp17_input_iterator<_InputIterator>::value>,
912         class = enable_if_t<!__is_allocator<_Hash>::value>,
913         class = enable_if_t<!is_integral<_Hash>::value>,
914         class = enable_if_t<__is_allocator<_Allocator>::value>>
915unordered_set(_InputIterator, _InputIterator,
916              typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
917  -> unordered_set<__iter_value_type<_InputIterator>, _Hash,
918                   equal_to<__iter_value_type<_InputIterator>>,
919                   _Allocator>;
920
921template<class _Tp, class _Allocator,
922         class = enable_if_t<__is_allocator<_Allocator>::value>>
923unordered_set(initializer_list<_Tp>, typename allocator_traits<_Allocator>::size_type, _Allocator)
924  -> unordered_set<_Tp, hash<_Tp>, equal_to<_Tp>, _Allocator>;
925
926template<class _Tp, class _Hash, class _Allocator,
927         class = enable_if_t<!__is_allocator<_Hash>::value>,
928         class = enable_if_t<!is_integral<_Hash>::value>,
929         class = enable_if_t<__is_allocator<_Allocator>::value>>
930unordered_set(initializer_list<_Tp>, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
931  -> unordered_set<_Tp, _Hash, equal_to<_Tp>, _Allocator>;
932#endif
933
934template <class _Value, class _Hash, class _Pred, class _Alloc>
935unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(size_type __n,
936        const hasher& __hf, const key_equal& __eql)
937    : __table_(__hf, __eql)
938{
939    _VSTD::__debug_db_insert_c(this);
940    __table_.rehash(__n);
941}
942
943template <class _Value, class _Hash, class _Pred, class _Alloc>
944unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(size_type __n,
945        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
946    : __table_(__hf, __eql, __a)
947{
948    _VSTD::__debug_db_insert_c(this);
949    __table_.rehash(__n);
950}
951
952template <class _Value, class _Hash, class _Pred, class _Alloc>
953template <class _InputIterator>
954unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
955        _InputIterator __first, _InputIterator __last)
956{
957    _VSTD::__debug_db_insert_c(this);
958    insert(__first, __last);
959}
960
961template <class _Value, class _Hash, class _Pred, class _Alloc>
962template <class _InputIterator>
963unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
964        _InputIterator __first, _InputIterator __last, size_type __n,
965        const hasher& __hf, const key_equal& __eql)
966    : __table_(__hf, __eql)
967{
968    _VSTD::__debug_db_insert_c(this);
969    __table_.rehash(__n);
970    insert(__first, __last);
971}
972
973template <class _Value, class _Hash, class _Pred, class _Alloc>
974template <class _InputIterator>
975unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
976        _InputIterator __first, _InputIterator __last, size_type __n,
977        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
978    : __table_(__hf, __eql, __a)
979{
980    _VSTD::__debug_db_insert_c(this);
981    __table_.rehash(__n);
982    insert(__first, __last);
983}
984
985template <class _Value, class _Hash, class _Pred, class _Alloc>
986inline
987unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
988        const allocator_type& __a)
989    : __table_(__a)
990{
991    _VSTD::__debug_db_insert_c(this);
992}
993
994template <class _Value, class _Hash, class _Pred, class _Alloc>
995unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
996        const unordered_set& __u)
997    : __table_(__u.__table_)
998{
999    _VSTD::__debug_db_insert_c(this);
1000    __table_.rehash(__u.bucket_count());
1001    insert(__u.begin(), __u.end());
1002}
1003
1004template <class _Value, class _Hash, class _Pred, class _Alloc>
1005unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
1006        const unordered_set& __u, const allocator_type& __a)
1007    : __table_(__u.__table_, __a)
1008{
1009    _VSTD::__debug_db_insert_c(this);
1010    __table_.rehash(__u.bucket_count());
1011    insert(__u.begin(), __u.end());
1012}
1013
1014#ifndef _LIBCPP_CXX03_LANG
1015
1016template <class _Value, class _Hash, class _Pred, class _Alloc>
1017inline
1018unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
1019        unordered_set&& __u)
1020    _NOEXCEPT_(is_nothrow_move_constructible<__table>::value)
1021    : __table_(_VSTD::move(__u.__table_))
1022{
1023    _VSTD::__debug_db_insert_c(this);
1024#if _LIBCPP_DEBUG_LEVEL == 2
1025    __get_db()->swap(this, _VSTD::addressof(__u));
1026#endif
1027}
1028
1029template <class _Value, class _Hash, class _Pred, class _Alloc>
1030unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
1031        unordered_set&& __u, const allocator_type& __a)
1032    : __table_(_VSTD::move(__u.__table_), __a)
1033{
1034    _VSTD::__debug_db_insert_c(this);
1035    if (__a != __u.get_allocator())
1036    {
1037        iterator __i = __u.begin();
1038        while (__u.size() != 0)
1039            __table_.__insert_unique(_VSTD::move(__u.__table_.remove(__i++)->__value_));
1040    }
1041#if _LIBCPP_DEBUG_LEVEL == 2
1042    else
1043        __get_db()->swap(this, _VSTD::addressof(__u));
1044#endif
1045}
1046
1047template <class _Value, class _Hash, class _Pred, class _Alloc>
1048unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
1049        initializer_list<value_type> __il)
1050{
1051    _VSTD::__debug_db_insert_c(this);
1052    insert(__il.begin(), __il.end());
1053}
1054
1055template <class _Value, class _Hash, class _Pred, class _Alloc>
1056unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
1057        initializer_list<value_type> __il, size_type __n, const hasher& __hf,
1058        const key_equal& __eql)
1059    : __table_(__hf, __eql)
1060{
1061    _VSTD::__debug_db_insert_c(this);
1062    __table_.rehash(__n);
1063    insert(__il.begin(), __il.end());
1064}
1065
1066template <class _Value, class _Hash, class _Pred, class _Alloc>
1067unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
1068        initializer_list<value_type> __il, size_type __n, const hasher& __hf,
1069        const key_equal& __eql, const allocator_type& __a)
1070    : __table_(__hf, __eql, __a)
1071{
1072    _VSTD::__debug_db_insert_c(this);
1073    __table_.rehash(__n);
1074    insert(__il.begin(), __il.end());
1075}
1076
1077template <class _Value, class _Hash, class _Pred, class _Alloc>
1078inline
1079unordered_set<_Value, _Hash, _Pred, _Alloc>&
1080unordered_set<_Value, _Hash, _Pred, _Alloc>::operator=(unordered_set&& __u)
1081    _NOEXCEPT_(is_nothrow_move_assignable<__table>::value)
1082{
1083    __table_ = _VSTD::move(__u.__table_);
1084    return *this;
1085}
1086
1087template <class _Value, class _Hash, class _Pred, class _Alloc>
1088inline
1089unordered_set<_Value, _Hash, _Pred, _Alloc>&
1090unordered_set<_Value, _Hash, _Pred, _Alloc>::operator=(
1091        initializer_list<value_type> __il)
1092{
1093    __table_.__assign_unique(__il.begin(), __il.end());
1094    return *this;
1095}
1096
1097#endif // _LIBCPP_CXX03_LANG
1098
1099template <class _Value, class _Hash, class _Pred, class _Alloc>
1100template <class _InputIterator>
1101inline
1102void
1103unordered_set<_Value, _Hash, _Pred, _Alloc>::insert(_InputIterator __first,
1104                                                    _InputIterator __last)
1105{
1106    for (; __first != __last; ++__first)
1107        __table_.__insert_unique(*__first);
1108}
1109
1110template <class _Value, class _Hash, class _Pred, class _Alloc>
1111inline _LIBCPP_INLINE_VISIBILITY
1112void
1113swap(unordered_set<_Value, _Hash, _Pred, _Alloc>& __x,
1114     unordered_set<_Value, _Hash, _Pred, _Alloc>& __y)
1115    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
1116{
1117    __x.swap(__y);
1118}
1119
1120#if _LIBCPP_STD_VER > 17
1121template <class _Value, class _Hash, class _Pred, class _Alloc,
1122          class _Predicate>
1123inline _LIBCPP_INLINE_VISIBILITY
1124    typename unordered_set<_Value, _Hash, _Pred, _Alloc>::size_type
1125    erase_if(unordered_set<_Value, _Hash, _Pred, _Alloc>& __c,
1126             _Predicate __pred) {
1127  return _VSTD::__libcpp_erase_if_container(__c, __pred);
1128}
1129#endif
1130
1131template <class _Value, class _Hash, class _Pred, class _Alloc>
1132bool
1133operator==(const unordered_set<_Value, _Hash, _Pred, _Alloc>& __x,
1134           const unordered_set<_Value, _Hash, _Pred, _Alloc>& __y)
1135{
1136    if (__x.size() != __y.size())
1137        return false;
1138    typedef typename unordered_set<_Value, _Hash, _Pred, _Alloc>::const_iterator
1139                                                                 const_iterator;
1140    for (const_iterator __i = __x.begin(), __ex = __x.end(), __ey = __y.end();
1141            __i != __ex; ++__i)
1142    {
1143        const_iterator __j = __y.find(*__i);
1144        if (__j == __ey || !(*__i == *__j))
1145            return false;
1146    }
1147    return true;
1148}
1149
1150template <class _Value, class _Hash, class _Pred, class _Alloc>
1151inline _LIBCPP_INLINE_VISIBILITY
1152bool
1153operator!=(const unordered_set<_Value, _Hash, _Pred, _Alloc>& __x,
1154           const unordered_set<_Value, _Hash, _Pred, _Alloc>& __y)
1155{
1156    return !(__x == __y);
1157}
1158
1159template <class _Value, class _Hash = hash<_Value>, class _Pred = equal_to<_Value>,
1160          class _Alloc = allocator<_Value> >
1161class _LIBCPP_TEMPLATE_VIS unordered_multiset
1162{
1163public:
1164    // types
1165    typedef _Value                                                     key_type;
1166    typedef key_type                                                   value_type;
1167    typedef __identity_t<_Hash>                                        hasher;
1168    typedef __identity_t<_Pred>                                        key_equal;
1169    typedef __identity_t<_Alloc>                                       allocator_type;
1170    typedef value_type&                                                reference;
1171    typedef const value_type&                                          const_reference;
1172    static_assert((is_same<value_type, typename allocator_type::value_type>::value),
1173                  "Invalid allocator::value_type");
1174
1175private:
1176    typedef __hash_table<value_type, hasher, key_equal, allocator_type> __table;
1177
1178    __table __table_;
1179
1180public:
1181    typedef typename __table::pointer         pointer;
1182    typedef typename __table::const_pointer   const_pointer;
1183    typedef typename __table::size_type       size_type;
1184    typedef typename __table::difference_type difference_type;
1185
1186    typedef typename __table::const_iterator       iterator;
1187    typedef typename __table::const_iterator       const_iterator;
1188    typedef typename __table::const_local_iterator local_iterator;
1189    typedef typename __table::const_local_iterator const_local_iterator;
1190
1191#if _LIBCPP_STD_VER > 14
1192    typedef __set_node_handle<typename __table::__node, allocator_type> node_type;
1193#endif
1194
1195    template <class _Value2, class _Hash2, class _Pred2, class _Alloc2>
1196        friend class _LIBCPP_TEMPLATE_VIS unordered_set;
1197    template <class _Value2, class _Hash2, class _Pred2, class _Alloc2>
1198        friend class _LIBCPP_TEMPLATE_VIS unordered_multiset;
1199
1200    _LIBCPP_INLINE_VISIBILITY
1201    unordered_multiset()
1202        _NOEXCEPT_(is_nothrow_default_constructible<__table>::value)
1203    {
1204        _VSTD::__debug_db_insert_c(this);
1205    }
1206    explicit unordered_multiset(size_type __n, const hasher& __hf = hasher(),
1207                                const key_equal& __eql = key_equal());
1208    unordered_multiset(size_type __n, const hasher& __hf,
1209                       const key_equal& __eql, const allocator_type& __a);
1210#if _LIBCPP_STD_VER > 11
1211    inline _LIBCPP_INLINE_VISIBILITY
1212    unordered_multiset(size_type __n, const allocator_type& __a)
1213        : unordered_multiset(__n, hasher(), key_equal(), __a) {}
1214    inline _LIBCPP_INLINE_VISIBILITY
1215    unordered_multiset(size_type __n, const hasher& __hf, const allocator_type& __a)
1216        : unordered_multiset(__n, __hf, key_equal(), __a) {}
1217#endif
1218    template <class _InputIterator>
1219        unordered_multiset(_InputIterator __first, _InputIterator __last);
1220    template <class _InputIterator>
1221        unordered_multiset(_InputIterator __first, _InputIterator __last,
1222                      size_type __n, const hasher& __hf = hasher(),
1223                      const key_equal& __eql = key_equal());
1224    template <class _InputIterator>
1225        unordered_multiset(_InputIterator __first, _InputIterator __last,
1226                      size_type __n , const hasher& __hf,
1227                      const key_equal& __eql, const allocator_type& __a);
1228#if _LIBCPP_STD_VER > 11
1229    template <class _InputIterator>
1230    inline _LIBCPP_INLINE_VISIBILITY
1231    unordered_multiset(_InputIterator __first, _InputIterator __last,
1232                       size_type __n, const allocator_type& __a)
1233        : unordered_multiset(__first, __last, __n, hasher(), key_equal(), __a) {}
1234    template <class _InputIterator>
1235    inline _LIBCPP_INLINE_VISIBILITY
1236    unordered_multiset(_InputIterator __first, _InputIterator __last,
1237                       size_type __n, const hasher& __hf, const allocator_type& __a)
1238        : unordered_multiset(__first, __last, __n, __hf, key_equal(), __a) {}
1239#endif
1240    _LIBCPP_INLINE_VISIBILITY
1241    explicit unordered_multiset(const allocator_type& __a);
1242    unordered_multiset(const unordered_multiset& __u);
1243    unordered_multiset(const unordered_multiset& __u, const allocator_type& __a);
1244#ifndef _LIBCPP_CXX03_LANG
1245    _LIBCPP_INLINE_VISIBILITY
1246    unordered_multiset(unordered_multiset&& __u)
1247        _NOEXCEPT_(is_nothrow_move_constructible<__table>::value);
1248    unordered_multiset(unordered_multiset&& __u, const allocator_type& __a);
1249    unordered_multiset(initializer_list<value_type> __il);
1250    unordered_multiset(initializer_list<value_type> __il, size_type __n,
1251                       const hasher& __hf = hasher(),
1252                       const key_equal& __eql = key_equal());
1253    unordered_multiset(initializer_list<value_type> __il, size_type __n,
1254                       const hasher& __hf, const key_equal& __eql,
1255                       const allocator_type& __a);
1256#if _LIBCPP_STD_VER > 11
1257    inline _LIBCPP_INLINE_VISIBILITY
1258    unordered_multiset(initializer_list<value_type> __il, size_type __n, const allocator_type& __a)
1259      : unordered_multiset(__il, __n, hasher(), key_equal(), __a) {}
1260    inline _LIBCPP_INLINE_VISIBILITY
1261    unordered_multiset(initializer_list<value_type> __il, size_type __n, const hasher& __hf, const allocator_type& __a)
1262      : unordered_multiset(__il, __n, __hf, key_equal(), __a) {}
1263#endif
1264#endif // _LIBCPP_CXX03_LANG
1265    _LIBCPP_INLINE_VISIBILITY
1266    ~unordered_multiset() {
1267        static_assert(sizeof(__diagnose_unordered_container_requirements<_Value, _Hash, _Pred>(0)), "");
1268    }
1269
1270    _LIBCPP_INLINE_VISIBILITY
1271    unordered_multiset& operator=(const unordered_multiset& __u)
1272    {
1273        __table_ = __u.__table_;
1274        return *this;
1275    }
1276#ifndef _LIBCPP_CXX03_LANG
1277    _LIBCPP_INLINE_VISIBILITY
1278    unordered_multiset& operator=(unordered_multiset&& __u)
1279        _NOEXCEPT_(is_nothrow_move_assignable<__table>::value);
1280    unordered_multiset& operator=(initializer_list<value_type> __il);
1281#endif // _LIBCPP_CXX03_LANG
1282
1283    _LIBCPP_INLINE_VISIBILITY
1284    allocator_type get_allocator() const _NOEXCEPT
1285        {return allocator_type(__table_.__node_alloc());}
1286
1287    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1288    bool      empty() const _NOEXCEPT {return __table_.size() == 0;}
1289    _LIBCPP_INLINE_VISIBILITY
1290    size_type size() const _NOEXCEPT  {return __table_.size();}
1291    _LIBCPP_INLINE_VISIBILITY
1292    size_type max_size() const _NOEXCEPT {return __table_.max_size();}
1293
1294    _LIBCPP_INLINE_VISIBILITY
1295    iterator       begin() _NOEXCEPT        {return __table_.begin();}
1296    _LIBCPP_INLINE_VISIBILITY
1297    iterator       end() _NOEXCEPT          {return __table_.end();}
1298    _LIBCPP_INLINE_VISIBILITY
1299    const_iterator begin()  const _NOEXCEPT {return __table_.begin();}
1300    _LIBCPP_INLINE_VISIBILITY
1301    const_iterator end()    const _NOEXCEPT {return __table_.end();}
1302    _LIBCPP_INLINE_VISIBILITY
1303    const_iterator cbegin() const _NOEXCEPT {return __table_.begin();}
1304    _LIBCPP_INLINE_VISIBILITY
1305    const_iterator cend()   const _NOEXCEPT {return __table_.end();}
1306
1307#ifndef _LIBCPP_CXX03_LANG
1308    template <class... _Args>
1309        _LIBCPP_INLINE_VISIBILITY
1310        iterator emplace(_Args&&... __args)
1311            {return __table_.__emplace_multi(_VSTD::forward<_Args>(__args)...);}
1312    template <class... _Args>
1313        _LIBCPP_INLINE_VISIBILITY
1314        iterator emplace_hint(const_iterator __p, _Args&&... __args)
1315            {return __table_.__emplace_hint_multi(__p, _VSTD::forward<_Args>(__args)...);}
1316
1317    _LIBCPP_INLINE_VISIBILITY
1318    iterator insert(value_type&& __x) {return __table_.__insert_multi(_VSTD::move(__x));}
1319    _LIBCPP_INLINE_VISIBILITY
1320    iterator insert(const_iterator __p, value_type&& __x)
1321        {return __table_.__insert_multi(__p, _VSTD::move(__x));}
1322    _LIBCPP_INLINE_VISIBILITY
1323    void insert(initializer_list<value_type> __il)
1324        {insert(__il.begin(), __il.end());}
1325#endif // _LIBCPP_CXX03_LANG
1326
1327    _LIBCPP_INLINE_VISIBILITY
1328    iterator insert(const value_type& __x) {return __table_.__insert_multi(__x);}
1329
1330    _LIBCPP_INLINE_VISIBILITY
1331    iterator insert(const_iterator __p, const value_type& __x)
1332        {return __table_.__insert_multi(__p, __x);}
1333
1334    template <class _InputIterator>
1335        _LIBCPP_INLINE_VISIBILITY
1336        void insert(_InputIterator __first, _InputIterator __last);
1337
1338#if _LIBCPP_STD_VER > 14
1339    _LIBCPP_INLINE_VISIBILITY
1340    iterator insert(node_type&& __nh)
1341    {
1342        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
1343            "node_type with incompatible allocator passed to unordered_multiset::insert()");
1344        return __table_.template __node_handle_insert_multi<node_type>(
1345            _VSTD::move(__nh));
1346    }
1347    _LIBCPP_INLINE_VISIBILITY
1348    iterator insert(const_iterator __hint, node_type&& __nh)
1349    {
1350        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
1351            "node_type with incompatible allocator passed to unordered_multiset::insert()");
1352        return __table_.template __node_handle_insert_multi<node_type>(
1353            __hint, _VSTD::move(__nh));
1354    }
1355    _LIBCPP_INLINE_VISIBILITY
1356    node_type extract(const_iterator __position)
1357    {
1358        return __table_.template __node_handle_extract<node_type>(
1359            __position);
1360    }
1361    _LIBCPP_INLINE_VISIBILITY
1362    node_type extract(key_type const& __key)
1363    {
1364        return __table_.template __node_handle_extract<node_type>(__key);
1365    }
1366
1367    template <class _H2, class _P2>
1368    _LIBCPP_INLINE_VISIBILITY
1369    void merge(unordered_multiset<key_type, _H2, _P2, allocator_type>& __source)
1370    {
1371        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
1372                       "merging container with incompatible allocator");
1373        return __table_.__node_handle_merge_multi(__source.__table_);
1374    }
1375    template <class _H2, class _P2>
1376    _LIBCPP_INLINE_VISIBILITY
1377    void merge(unordered_multiset<key_type, _H2, _P2, allocator_type>&& __source)
1378    {
1379        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
1380                       "merging container with incompatible allocator");
1381        return __table_.__node_handle_merge_multi(__source.__table_);
1382    }
1383    template <class _H2, class _P2>
1384    _LIBCPP_INLINE_VISIBILITY
1385    void merge(unordered_set<key_type, _H2, _P2, allocator_type>& __source)
1386    {
1387        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
1388                       "merging container with incompatible allocator");
1389        return __table_.__node_handle_merge_multi(__source.__table_);
1390    }
1391    template <class _H2, class _P2>
1392    _LIBCPP_INLINE_VISIBILITY
1393    void merge(unordered_set<key_type, _H2, _P2, allocator_type>&& __source)
1394    {
1395        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
1396                       "merging container with incompatible allocator");
1397        return __table_.__node_handle_merge_multi(__source.__table_);
1398    }
1399#endif
1400
1401    _LIBCPP_INLINE_VISIBILITY
1402    iterator erase(const_iterator __p) {return __table_.erase(__p);}
1403    _LIBCPP_INLINE_VISIBILITY
1404    size_type erase(const key_type& __k) {return __table_.__erase_multi(__k);}
1405    _LIBCPP_INLINE_VISIBILITY
1406    iterator erase(const_iterator __first, const_iterator __last)
1407        {return __table_.erase(__first, __last);}
1408    _LIBCPP_INLINE_VISIBILITY
1409    void clear() _NOEXCEPT {__table_.clear();}
1410
1411    _LIBCPP_INLINE_VISIBILITY
1412    void swap(unordered_multiset& __u)
1413        _NOEXCEPT_(__is_nothrow_swappable<__table>::value)
1414        {__table_.swap(__u.__table_);}
1415
1416    _LIBCPP_INLINE_VISIBILITY
1417    hasher hash_function() const {return __table_.hash_function();}
1418    _LIBCPP_INLINE_VISIBILITY
1419    key_equal key_eq() const {return __table_.key_eq();}
1420
1421    _LIBCPP_INLINE_VISIBILITY
1422    iterator       find(const key_type& __k)       {return __table_.find(__k);}
1423    _LIBCPP_INLINE_VISIBILITY
1424    const_iterator find(const key_type& __k) const {return __table_.find(__k);}
1425#if _LIBCPP_STD_VER > 17
1426    template<class _K2, enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1427    _LIBCPP_INLINE_VISIBILITY
1428    iterator       find(const _K2& __k)            {return __table_.find(__k);}
1429    template<class _K2, enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1430    _LIBCPP_INLINE_VISIBILITY
1431    const_iterator find(const _K2& __k) const      {return __table_.find(__k);}
1432#endif // _LIBCPP_STD_VER > 17
1433
1434    _LIBCPP_INLINE_VISIBILITY
1435    size_type count(const key_type& __k) const {return __table_.__count_multi(__k);}
1436#if _LIBCPP_STD_VER > 17
1437    template<class _K2, enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1438    _LIBCPP_INLINE_VISIBILITY
1439    size_type count(const _K2& __k) const      {return __table_.__count_multi(__k);}
1440#endif // _LIBCPP_STD_VER > 17
1441
1442#if _LIBCPP_STD_VER > 17
1443    _LIBCPP_INLINE_VISIBILITY
1444    bool contains(const key_type& __k) const {return find(__k) != end();}
1445
1446    template<class _K2, enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1447    _LIBCPP_INLINE_VISIBILITY
1448    bool contains(const _K2& __k) const      {return find(__k) != end();}
1449#endif // _LIBCPP_STD_VER > 17
1450
1451    _LIBCPP_INLINE_VISIBILITY
1452    pair<iterator, iterator>             equal_range(const key_type& __k)
1453        {return __table_.__equal_range_multi(__k);}
1454    _LIBCPP_INLINE_VISIBILITY
1455    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
1456        {return __table_.__equal_range_multi(__k);}
1457#if _LIBCPP_STD_VER > 17
1458    template<class _K2, enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1459    _LIBCPP_INLINE_VISIBILITY
1460    pair<iterator, iterator>             equal_range(const _K2& __k)
1461        {return __table_.__equal_range_multi(__k);}
1462    template<class _K2, enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1463    _LIBCPP_INLINE_VISIBILITY
1464    pair<const_iterator, const_iterator> equal_range(const _K2& __k) const
1465        {return __table_.__equal_range_multi(__k);}
1466#endif // _LIBCPP_STD_VER > 17
1467
1468    _LIBCPP_INLINE_VISIBILITY
1469    size_type bucket_count() const _NOEXCEPT {return __table_.bucket_count();}
1470    _LIBCPP_INLINE_VISIBILITY
1471    size_type max_bucket_count() const _NOEXCEPT {return __table_.max_bucket_count();}
1472
1473    _LIBCPP_INLINE_VISIBILITY
1474    size_type bucket_size(size_type __n) const {return __table_.bucket_size(__n);}
1475    _LIBCPP_INLINE_VISIBILITY
1476    size_type bucket(const key_type& __k) const {return __table_.bucket(__k);}
1477
1478    _LIBCPP_INLINE_VISIBILITY
1479    local_iterator       begin(size_type __n)        {return __table_.begin(__n);}
1480    _LIBCPP_INLINE_VISIBILITY
1481    local_iterator       end(size_type __n)          {return __table_.end(__n);}
1482    _LIBCPP_INLINE_VISIBILITY
1483    const_local_iterator begin(size_type __n) const  {return __table_.cbegin(__n);}
1484    _LIBCPP_INLINE_VISIBILITY
1485    const_local_iterator end(size_type __n) const    {return __table_.cend(__n);}
1486    _LIBCPP_INLINE_VISIBILITY
1487    const_local_iterator cbegin(size_type __n) const {return __table_.cbegin(__n);}
1488    _LIBCPP_INLINE_VISIBILITY
1489    const_local_iterator cend(size_type __n) const   {return __table_.cend(__n);}
1490
1491    _LIBCPP_INLINE_VISIBILITY
1492    float load_factor() const _NOEXCEPT {return __table_.load_factor();}
1493    _LIBCPP_INLINE_VISIBILITY
1494    float max_load_factor() const _NOEXCEPT {return __table_.max_load_factor();}
1495    _LIBCPP_INLINE_VISIBILITY
1496    void max_load_factor(float __mlf) {__table_.max_load_factor(__mlf);}
1497    _LIBCPP_INLINE_VISIBILITY
1498    void rehash(size_type __n) {__table_.rehash(__n);}
1499    _LIBCPP_INLINE_VISIBILITY
1500    void reserve(size_type __n) {__table_.reserve(__n);}
1501
1502#if _LIBCPP_DEBUG_LEVEL == 2
1503
1504    bool __dereferenceable(const const_iterator* __i) const
1505        {return __table_.__dereferenceable(__i);}
1506    bool __decrementable(const const_iterator* __i) const
1507        {return __table_.__decrementable(__i);}
1508    bool __addable(const const_iterator* __i, ptrdiff_t __n) const
1509        {return __table_.__addable(__i, __n);}
1510    bool __subscriptable(const const_iterator* __i, ptrdiff_t __n) const
1511        {return __table_.__addable(__i, __n);}
1512
1513#endif // _LIBCPP_DEBUG_LEVEL == 2
1514
1515};
1516
1517#if _LIBCPP_STD_VER >= 17
1518template<class _InputIterator,
1519         class _Hash = hash<__iter_value_type<_InputIterator>>,
1520         class _Pred = equal_to<__iter_value_type<_InputIterator>>,
1521         class _Allocator = allocator<__iter_value_type<_InputIterator>>,
1522         class = enable_if_t<__is_cpp17_input_iterator<_InputIterator>::value>,
1523         class = enable_if_t<!__is_allocator<_Hash>::value>,
1524         class = enable_if_t<!is_integral<_Hash>::value>,
1525         class = enable_if_t<!__is_allocator<_Pred>::value>,
1526         class = enable_if_t<__is_allocator<_Allocator>::value>>
1527unordered_multiset(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type = 0,
1528              _Hash = _Hash(), _Pred = _Pred(), _Allocator = _Allocator())
1529  -> unordered_multiset<__iter_value_type<_InputIterator>, _Hash, _Pred, _Allocator>;
1530
1531template<class _Tp, class _Hash = hash<_Tp>,
1532         class _Pred = equal_to<_Tp>, class _Allocator = allocator<_Tp>,
1533         class = enable_if_t<!__is_allocator<_Hash>::value>,
1534         class = enable_if_t<!is_integral<_Hash>::value>,
1535         class = enable_if_t<!__is_allocator<_Pred>::value>,
1536         class = enable_if_t<__is_allocator<_Allocator>::value>>
1537unordered_multiset(initializer_list<_Tp>, typename allocator_traits<_Allocator>::size_type = 0,
1538              _Hash = _Hash(), _Pred = _Pred(), _Allocator = _Allocator())
1539  -> unordered_multiset<_Tp, _Hash, _Pred, _Allocator>;
1540
1541template<class _InputIterator, class _Allocator,
1542         class = enable_if_t<__is_cpp17_input_iterator<_InputIterator>::value>,
1543         class = enable_if_t<__is_allocator<_Allocator>::value>>
1544unordered_multiset(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type, _Allocator)
1545  -> unordered_multiset<__iter_value_type<_InputIterator>,
1546                   hash<__iter_value_type<_InputIterator>>,
1547                   equal_to<__iter_value_type<_InputIterator>>,
1548                   _Allocator>;
1549
1550template<class _InputIterator, class _Hash, class _Allocator,
1551         class = enable_if_t<__is_cpp17_input_iterator<_InputIterator>::value>,
1552         class = enable_if_t<!__is_allocator<_Hash>::value>,
1553         class = enable_if_t<!is_integral<_Hash>::value>,
1554         class = enable_if_t<__is_allocator<_Allocator>::value>>
1555unordered_multiset(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type,
1556              _Hash, _Allocator)
1557  -> unordered_multiset<__iter_value_type<_InputIterator>, _Hash,
1558                   equal_to<__iter_value_type<_InputIterator>>,
1559                   _Allocator>;
1560
1561template<class _Tp, class _Allocator,
1562         class = enable_if_t<__is_allocator<_Allocator>::value>>
1563unordered_multiset(initializer_list<_Tp>, typename allocator_traits<_Allocator>::size_type, _Allocator)
1564  -> unordered_multiset<_Tp, hash<_Tp>, equal_to<_Tp>, _Allocator>;
1565
1566template<class _Tp, class _Hash, class _Allocator,
1567         class = enable_if_t<!__is_allocator<_Hash>::value>,
1568         class = enable_if_t<!is_integral<_Hash>::value>,
1569         class = enable_if_t<__is_allocator<_Allocator>::value>>
1570unordered_multiset(initializer_list<_Tp>, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
1571  -> unordered_multiset<_Tp, _Hash, equal_to<_Tp>, _Allocator>;
1572#endif
1573
1574template <class _Value, class _Hash, class _Pred, class _Alloc>
1575unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
1576        size_type __n, const hasher& __hf, const key_equal& __eql)
1577    : __table_(__hf, __eql)
1578{
1579    _VSTD::__debug_db_insert_c(this);
1580    __table_.rehash(__n);
1581}
1582
1583template <class _Value, class _Hash, class _Pred, class _Alloc>
1584unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
1585        size_type __n, const hasher& __hf, const key_equal& __eql,
1586        const allocator_type& __a)
1587    : __table_(__hf, __eql, __a)
1588{
1589    _VSTD::__debug_db_insert_c(this);
1590    __table_.rehash(__n);
1591}
1592
1593template <class _Value, class _Hash, class _Pred, class _Alloc>
1594template <class _InputIterator>
1595unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
1596        _InputIterator __first, _InputIterator __last)
1597{
1598    _VSTD::__debug_db_insert_c(this);
1599    insert(__first, __last);
1600}
1601
1602template <class _Value, class _Hash, class _Pred, class _Alloc>
1603template <class _InputIterator>
1604unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
1605        _InputIterator __first, _InputIterator __last, size_type __n,
1606        const hasher& __hf, const key_equal& __eql)
1607    : __table_(__hf, __eql)
1608{
1609    _VSTD::__debug_db_insert_c(this);
1610    __table_.rehash(__n);
1611    insert(__first, __last);
1612}
1613
1614template <class _Value, class _Hash, class _Pred, class _Alloc>
1615template <class _InputIterator>
1616unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
1617        _InputIterator __first, _InputIterator __last, size_type __n,
1618        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
1619    : __table_(__hf, __eql, __a)
1620{
1621    _VSTD::__debug_db_insert_c(this);
1622    __table_.rehash(__n);
1623    insert(__first, __last);
1624}
1625
1626template <class _Value, class _Hash, class _Pred, class _Alloc>
1627inline
1628unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
1629        const allocator_type& __a)
1630    : __table_(__a)
1631{
1632    _VSTD::__debug_db_insert_c(this);
1633}
1634
1635template <class _Value, class _Hash, class _Pred, class _Alloc>
1636unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
1637        const unordered_multiset& __u)
1638    : __table_(__u.__table_)
1639{
1640    _VSTD::__debug_db_insert_c(this);
1641    __table_.rehash(__u.bucket_count());
1642    insert(__u.begin(), __u.end());
1643}
1644
1645template <class _Value, class _Hash, class _Pred, class _Alloc>
1646unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
1647        const unordered_multiset& __u, const allocator_type& __a)
1648    : __table_(__u.__table_, __a)
1649{
1650    _VSTD::__debug_db_insert_c(this);
1651    __table_.rehash(__u.bucket_count());
1652    insert(__u.begin(), __u.end());
1653}
1654
1655#ifndef _LIBCPP_CXX03_LANG
1656
1657template <class _Value, class _Hash, class _Pred, class _Alloc>
1658inline
1659unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
1660        unordered_multiset&& __u)
1661    _NOEXCEPT_(is_nothrow_move_constructible<__table>::value)
1662    : __table_(_VSTD::move(__u.__table_))
1663{
1664    _VSTD::__debug_db_insert_c(this);
1665#if _LIBCPP_DEBUG_LEVEL == 2
1666    __get_db()->swap(this, _VSTD::addressof(__u));
1667#endif
1668}
1669
1670template <class _Value, class _Hash, class _Pred, class _Alloc>
1671unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
1672        unordered_multiset&& __u, const allocator_type& __a)
1673    : __table_(_VSTD::move(__u.__table_), __a)
1674{
1675    _VSTD::__debug_db_insert_c(this);
1676    if (__a != __u.get_allocator())
1677    {
1678        iterator __i = __u.begin();
1679        while (__u.size() != 0)
1680            __table_.__insert_multi(_VSTD::move(__u.__table_.remove(__i++)->__value_));
1681    }
1682#if _LIBCPP_DEBUG_LEVEL == 2
1683    else
1684        __get_db()->swap(this, _VSTD::addressof(__u));
1685#endif
1686}
1687
1688template <class _Value, class _Hash, class _Pred, class _Alloc>
1689unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
1690        initializer_list<value_type> __il)
1691{
1692    _VSTD::__debug_db_insert_c(this);
1693    insert(__il.begin(), __il.end());
1694}
1695
1696template <class _Value, class _Hash, class _Pred, class _Alloc>
1697unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
1698        initializer_list<value_type> __il, size_type __n, const hasher& __hf,
1699        const key_equal& __eql)
1700    : __table_(__hf, __eql)
1701{
1702    _VSTD::__debug_db_insert_c(this);
1703    __table_.rehash(__n);
1704    insert(__il.begin(), __il.end());
1705}
1706
1707template <class _Value, class _Hash, class _Pred, class _Alloc>
1708unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
1709        initializer_list<value_type> __il, size_type __n, const hasher& __hf,
1710        const key_equal& __eql, const allocator_type& __a)
1711    : __table_(__hf, __eql, __a)
1712{
1713    _VSTD::__debug_db_insert_c(this);
1714    __table_.rehash(__n);
1715    insert(__il.begin(), __il.end());
1716}
1717
1718template <class _Value, class _Hash, class _Pred, class _Alloc>
1719inline
1720unordered_multiset<_Value, _Hash, _Pred, _Alloc>&
1721unordered_multiset<_Value, _Hash, _Pred, _Alloc>::operator=(
1722        unordered_multiset&& __u)
1723    _NOEXCEPT_(is_nothrow_move_assignable<__table>::value)
1724{
1725    __table_ = _VSTD::move(__u.__table_);
1726    return *this;
1727}
1728
1729template <class _Value, class _Hash, class _Pred, class _Alloc>
1730inline
1731unordered_multiset<_Value, _Hash, _Pred, _Alloc>&
1732unordered_multiset<_Value, _Hash, _Pred, _Alloc>::operator=(
1733        initializer_list<value_type> __il)
1734{
1735    __table_.__assign_multi(__il.begin(), __il.end());
1736    return *this;
1737}
1738
1739#endif // _LIBCPP_CXX03_LANG
1740
1741template <class _Value, class _Hash, class _Pred, class _Alloc>
1742template <class _InputIterator>
1743inline
1744void
1745unordered_multiset<_Value, _Hash, _Pred, _Alloc>::insert(_InputIterator __first,
1746                                                         _InputIterator __last)
1747{
1748    for (; __first != __last; ++__first)
1749        __table_.__insert_multi(*__first);
1750}
1751
1752template <class _Value, class _Hash, class _Pred, class _Alloc>
1753inline _LIBCPP_INLINE_VISIBILITY
1754void
1755swap(unordered_multiset<_Value, _Hash, _Pred, _Alloc>& __x,
1756     unordered_multiset<_Value, _Hash, _Pred, _Alloc>& __y)
1757    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
1758{
1759    __x.swap(__y);
1760}
1761
1762#if _LIBCPP_STD_VER > 17
1763template <class _Value, class _Hash, class _Pred, class _Alloc,
1764          class _Predicate>
1765inline _LIBCPP_INLINE_VISIBILITY
1766    typename unordered_multiset<_Value, _Hash, _Pred, _Alloc>::size_type
1767    erase_if(unordered_multiset<_Value, _Hash, _Pred, _Alloc>& __c,
1768             _Predicate __pred) {
1769  return _VSTD::__libcpp_erase_if_container(__c, __pred);
1770}
1771#endif
1772
1773template <class _Value, class _Hash, class _Pred, class _Alloc>
1774bool
1775operator==(const unordered_multiset<_Value, _Hash, _Pred, _Alloc>& __x,
1776           const unordered_multiset<_Value, _Hash, _Pred, _Alloc>& __y)
1777{
1778    if (__x.size() != __y.size())
1779        return false;
1780    typedef typename unordered_multiset<_Value, _Hash, _Pred, _Alloc>::const_iterator
1781                                                                 const_iterator;
1782    typedef pair<const_iterator, const_iterator> _EqRng;
1783    for (const_iterator __i = __x.begin(), __ex = __x.end(); __i != __ex;)
1784    {
1785        _EqRng __xeq = __x.equal_range(*__i);
1786        _EqRng __yeq = __y.equal_range(*__i);
1787        if (_VSTD::distance(__xeq.first, __xeq.second) !=
1788            _VSTD::distance(__yeq.first, __yeq.second) ||
1789                  !_VSTD::is_permutation(__xeq.first, __xeq.second, __yeq.first))
1790            return false;
1791        __i = __xeq.second;
1792    }
1793    return true;
1794}
1795
1796template <class _Value, class _Hash, class _Pred, class _Alloc>
1797inline _LIBCPP_INLINE_VISIBILITY
1798bool
1799operator!=(const unordered_multiset<_Value, _Hash, _Pred, _Alloc>& __x,
1800           const unordered_multiset<_Value, _Hash, _Pred, _Alloc>& __y)
1801{
1802    return !(__x == __y);
1803}
1804
1805_LIBCPP_END_NAMESPACE_STD
1806
1807#endif // _LIBCPP_UNORDERED_SET
1808