xref: /freebsd/contrib/llvm-project/libcxx/include/unordered_map (revision a0ca4af9455b844c5e094fc1b09b1390ffa979fc)
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_MAP
11#define _LIBCPP_UNORDERED_MAP
12
13/*
14
15    unordered_map synopsis
16
17#include <initializer_list>
18
19namespace std
20{
21
22template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
23          class Alloc = allocator<pair<const Key, T>>>
24class unordered_map
25{
26public:
27    // types
28    typedef Key                                                        key_type;
29    typedef T                                                          mapped_type;
30    typedef Hash                                                       hasher;
31    typedef Pred                                                       key_equal;
32    typedef Alloc                                                      allocator_type;
33    typedef pair<const key_type, mapped_type>                          value_type;
34    typedef value_type&                                                reference;
35    typedef const value_type&                                          const_reference;
36    typedef typename allocator_traits<allocator_type>::pointer         pointer;
37    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
38    typedef typename allocator_traits<allocator_type>::size_type       size_type;
39    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
40
41    typedef /unspecified/ iterator;
42    typedef /unspecified/ const_iterator;
43    typedef /unspecified/ local_iterator;
44    typedef /unspecified/ const_local_iterator;
45
46    typedef unspecified                             node_type;            // C++17
47    typedef INSERT_RETURN_TYPE<iterator, node_type> insert_return_type;   // C++17
48
49    unordered_map()
50        noexcept(
51            is_nothrow_default_constructible<hasher>::value &&
52            is_nothrow_default_constructible<key_equal>::value &&
53            is_nothrow_default_constructible<allocator_type>::value);
54    explicit unordered_map(size_type n, const hasher& hf = hasher(),
55                           const key_equal& eql = key_equal(),
56                           const allocator_type& a = allocator_type());
57    template <class InputIterator>
58        unordered_map(InputIterator f, InputIterator l,
59                      size_type n = 0, const hasher& hf = hasher(),
60                      const key_equal& eql = key_equal(),
61                      const allocator_type& a = allocator_type());
62    template<container-compatible-range<value_type> R>
63      unordered_map(from_range_t, R&& rg, size_type n = see below,
64        const hasher& hf = hasher(), const key_equal& eql = key_equal(),
65        const allocator_type& a = allocator_type()); // C++23
66
67    explicit unordered_map(const allocator_type&);
68    unordered_map(const unordered_map&);
69    unordered_map(const unordered_map&, const Allocator&);
70    unordered_map(unordered_map&&)
71        noexcept(
72            is_nothrow_move_constructible<hasher>::value &&
73            is_nothrow_move_constructible<key_equal>::value &&
74            is_nothrow_move_constructible<allocator_type>::value);
75    unordered_map(unordered_map&&, const Allocator&);
76    unordered_map(initializer_list<value_type>, size_type n = 0,
77                  const hasher& hf = hasher(), const key_equal& eql = key_equal(),
78                  const allocator_type& a = allocator_type());
79    unordered_map(size_type n, const allocator_type& a)
80      : unordered_map(n, hasher(), key_equal(), a) {}  // C++14
81    unordered_map(size_type n, const hasher& hf, const allocator_type& a)
82      : unordered_map(n, hf, key_equal(), a) {}  // C++14
83    template <class InputIterator>
84      unordered_map(InputIterator f, InputIterator l, size_type n, const allocator_type& a)
85      : unordered_map(f, l, n, hasher(), key_equal(), a) {}  // C++14
86    template <class InputIterator>
87      unordered_map(InputIterator f, InputIterator l, size_type n, const hasher& hf,
88        const allocator_type& a)
89      : unordered_map(f, l, n, hf, key_equal(), a) {}  // C++14
90    template<container-compatible-range<value_type> R>
91      unordered_map(from_range_t, R&& rg, size_type n, const allocator_type& a)
92        : unordered_map(from_range, std::forward<R>(rg), n, hasher(), key_equal(), a) { } // C++23
93    template<container-compatible-range<value_type> R>
94      unordered_map(from_range_t, R&& rg, size_type n, const hasher& hf, const allocator_type& a)
95        : unordered_map(from_range, std::forward<R>(rg), n, hf, key_equal(), a) { }       // C++23
96    unordered_map(initializer_list<value_type> il, size_type n, const allocator_type& a)
97      : unordered_map(il, n, hasher(), key_equal(), a) {}  // C++14
98    unordered_map(initializer_list<value_type> il, size_type n, const hasher& hf,
99      const allocator_type& a)
100      : unordered_map(il, n, hf, key_equal(), a) {}  // C++14
101    ~unordered_map();
102    unordered_map& operator=(const unordered_map&);
103    unordered_map& operator=(unordered_map&&)
104        noexcept(
105            allocator_type::propagate_on_container_move_assignment::value &&
106            is_nothrow_move_assignable<allocator_type>::value &&
107            is_nothrow_move_assignable<hasher>::value &&
108            is_nothrow_move_assignable<key_equal>::value);
109    unordered_map& operator=(initializer_list<value_type>);
110
111    allocator_type get_allocator() const noexcept;
112
113    bool      empty() const noexcept;
114    size_type size() const noexcept;
115    size_type max_size() const noexcept;
116
117    iterator       begin() noexcept;
118    iterator       end() noexcept;
119    const_iterator begin()  const noexcept;
120    const_iterator end()    const noexcept;
121    const_iterator cbegin() const noexcept;
122    const_iterator cend()   const noexcept;
123
124    template <class... Args>
125        pair<iterator, bool> emplace(Args&&... args);
126    template <class... Args>
127        iterator emplace_hint(const_iterator position, Args&&... args);
128    pair<iterator, bool> insert(const value_type& obj);
129    template <class P>
130        pair<iterator, bool> insert(P&& obj);
131    iterator insert(const_iterator hint, const value_type& obj);
132    template <class P>
133        iterator insert(const_iterator hint, P&& obj);
134    template <class InputIterator>
135        void insert(InputIterator first, InputIterator last);
136    template<container-compatible-range<value_type> R>
137      void insert_range(R&& rg);                                                      // C++23
138    void insert(initializer_list<value_type>);
139
140    node_type extract(const_iterator position);                                       // C++17
141    node_type extract(const key_type& x);                                             // C++17
142    insert_return_type insert(node_type&& nh);                                        // C++17
143    iterator           insert(const_iterator hint, node_type&& nh);                   // C++17
144
145    template <class... Args>
146        pair<iterator, bool> try_emplace(const key_type& k, Args&&... args);          // C++17
147    template <class... Args>
148        pair<iterator, bool> try_emplace(key_type&& k, Args&&... args);               // C++17
149    template <class... Args>
150        iterator try_emplace(const_iterator hint, const key_type& k, Args&&... args); // C++17
151    template <class... Args>
152        iterator try_emplace(const_iterator hint, key_type&& k, Args&&... args);      // C++17
153    template <class M>
154        pair<iterator, bool> insert_or_assign(const key_type& k, M&& obj);            // C++17
155    template <class M>
156        pair<iterator, bool> insert_or_assign(key_type&& k, M&& obj);                 // C++17
157    template <class M>
158        iterator insert_or_assign(const_iterator hint, const key_type& k, M&& obj);   // C++17
159    template <class M>
160        iterator insert_or_assign(const_iterator hint, key_type&& k, M&& obj);        // C++17
161
162    iterator erase(const_iterator position);
163    iterator erase(iterator position);  // C++14
164    size_type erase(const key_type& k);
165    iterator erase(const_iterator first, const_iterator last);
166    void clear() noexcept;
167
168    template<class H2, class P2>
169      void merge(unordered_map<Key, T, H2, P2, Allocator>& source);         // C++17
170    template<class H2, class P2>
171      void merge(unordered_map<Key, T, H2, P2, Allocator>&& source);        // C++17
172    template<class H2, class P2>
173      void merge(unordered_multimap<Key, T, H2, P2, Allocator>& source);    // C++17
174    template<class H2, class P2>
175      void merge(unordered_multimap<Key, T, H2, P2, Allocator>&& source);   // C++17
176
177    void swap(unordered_map&)
178        noexcept(
179            (!allocator_type::propagate_on_container_swap::value ||
180             __is_nothrow_swappable<allocator_type>::value) &&
181            __is_nothrow_swappable<hasher>::value &&
182            __is_nothrow_swappable<key_equal>::value);
183
184    hasher hash_function() const;
185    key_equal key_eq() const;
186
187    iterator       find(const key_type& k);
188    const_iterator find(const key_type& k) const;
189    template<typename K>
190        iterator find(const K& x);              // C++20
191    template<typename K>
192        const_iterator find(const K& x) const;  // C++20
193    size_type count(const key_type& k) const;
194    template<typename K>
195        size_type count(const K& k) const; // C++20
196    bool contains(const key_type& k) const; // C++20
197    template<typename K>
198        bool contains(const K& k) const; // C++20
199    pair<iterator, iterator>             equal_range(const key_type& k);
200    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
201    template<typename K>
202        pair<iterator, iterator>             equal_range(const K& k); // C++20
203    template<typename K>
204        pair<const_iterator, const_iterator> equal_range(const K& k) const; // C++20
205
206    mapped_type& operator[](const key_type& k);
207    mapped_type& operator[](key_type&& k);
208
209    mapped_type&       at(const key_type& k);
210    const mapped_type& at(const key_type& k) const;
211
212    size_type bucket_count() const noexcept;
213    size_type max_bucket_count() const noexcept;
214
215    size_type bucket_size(size_type n) const;
216    size_type bucket(const key_type& k) const;
217
218    local_iterator       begin(size_type n);
219    local_iterator       end(size_type n);
220    const_local_iterator begin(size_type n) const;
221    const_local_iterator end(size_type n) const;
222    const_local_iterator cbegin(size_type n) const;
223    const_local_iterator cend(size_type n) const;
224
225    float load_factor() const noexcept;
226    float max_load_factor() const noexcept;
227    void max_load_factor(float z);
228    void rehash(size_type n);
229    void reserve(size_type n);
230};
231
232template<class InputIterator,
233    class Hash = hash<iter_key_t<InputIterator>>, class Pred = equal_to<iter_key_t<InputIterator>>,
234    class Allocator = allocator<iter_to_alloc_t<InputIterator>>>
235unordered_map(InputIterator, InputIterator, typename see below::size_type = see below,
236    Hash = Hash(), Pred = Pred(), Allocator = Allocator())
237  -> unordered_map<iter_key_t<InputIterator>, iter_value_t<InputIterator>, Hash, Pred,
238    Allocator>; // C++17
239
240template<ranges::input_range R, class Hash = hash<range-key-type<R>>,
241         class Pred = equal_to<range-key-type<R>>,
242         class Allocator = allocator<range-to-alloc-type<R>>>
243  unordered_map(from_range_t, R&&, typename see below::size_type = see below,
244                Hash = Hash(), Pred = Pred(), Allocator = Allocator())
245    -> unordered_map<range-key-type<R>, range-mapped-type<R>, Hash, Pred, Allocator>; // C++23
246
247template<class Key, class T, class Hash = hash<Key>,
248    class Pred = equal_to<Key>, class Allocator = allocator<pair<const Key, T>>>
249unordered_map(initializer_list<pair<const Key, T>>, typename see below::size_type = see below,
250    Hash = Hash(), Pred = Pred(), Allocator = Allocator())
251  -> unordered_map<Key, T, Hash, Pred, Allocator>; // C++17
252
253template<class InputIterator, class Allocator>
254unordered_map(InputIterator, InputIterator, typename see below::size_type, Allocator)
255  -> unordered_map<iter_key_t<InputIterator>, iter_val_t<InputIterator>,
256        hash<iter_key_t<InputIterator>>, equal_to<iter_key_t<InputIterator>>, Allocator>; // C++17
257
258template<class InputIterator, class Allocator>
259unordered_map(InputIterator, InputIterator, Allocator)
260  -> unordered_map<iter_key_t<InputIterator>, iter_val_t<InputIterator>,
261        hash<iter_key_t<InputIterator>>, equal_to<iter_key_t<InputIterator>>, Allocator>; // C++17
262
263template<class InputIterator, class Hash, class Allocator>
264unordered_map(InputIterator, InputIterator, typename see below::size_type, Hash, Allocator)
265  -> unordered_map<iter_key_t<InputIterator>, iter_val_t<InputIterator>, Hash,
266          equal_to<iter_key_t<InputIterator>>, Allocator>; // C++17
267
268template<ranges::input_range R, class Allocator>
269  unordered_map(from_range_t, R&&, typename see below::size_type, Allocator)
270    -> unordered_map<range-key-type<R>, range-mapped-type<R>, hash<range-key-type<R>>,
271                      equal_to<range-key-type<R>>, Allocator>;   // C++23
272
273template<ranges::input_range R, class Allocator>
274  unordered_map(from_range_t, R&&, Allocator)
275    -> unordered_map<range-key-type<R>, range-mapped-type<R>, hash<range-key-type<R>>,
276                      equal_to<range-key-type<R>>, Allocator>;   // C++23
277
278template<ranges::input_range R, class Hash, class Allocator>
279  unordered_map(from_range_t, R&&, typename see below::size_type, Hash, Allocator)
280    -> unordered_map<range-key-type<R>, range-mapped-type<R>, Hash,
281                      equal_to<range-key-type<R>>, Allocator>;   // C++23
282
283template<class Key, class T, typename Allocator>
284unordered_map(initializer_list<pair<const Key, T>>, typename see below::size_type, Allocator)
285  -> unordered_map<Key, T, hash<Key>, equal_to<Key>, Allocator>; // C++17
286
287template<class Key, class T, typename Allocator>
288unordered_map(initializer_list<pair<const Key, T>>, Allocator)
289  -> unordered_map<Key, T, hash<Key>, equal_to<Key>, Allocator>; // C++17
290
291template<class Key, class T, class Hash, class Allocator>
292unordered_map(initializer_list<pair<const Key, T>>, typename see below::size_type, Hash, Allocator)
293  -> unordered_map<Key, T, Hash, equal_to<Key>, Allocator>; // C++17
294
295template <class Key, class T, class Hash, class Pred, class Alloc>
296    void swap(unordered_map<Key, T, Hash, Pred, Alloc>& x,
297              unordered_map<Key, T, Hash, Pred, Alloc>& y)
298              noexcept(noexcept(x.swap(y)));
299
300template <class Key, class T, class Hash, class Pred, class Alloc>
301    bool
302    operator==(const unordered_map<Key, T, Hash, Pred, Alloc>& x,
303               const unordered_map<Key, T, Hash, Pred, Alloc>& y);
304
305template <class Key, class T, class Hash, class Pred, class Alloc>
306    bool
307    operator!=(const unordered_map<Key, T, Hash, Pred, Alloc>& x,
308               const unordered_map<Key, T, Hash, Pred, Alloc>& y); // Removed in C++20
309
310template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
311          class Alloc = allocator<pair<const Key, T>>>
312class unordered_multimap
313{
314public:
315    // types
316    typedef Key                                                        key_type;
317    typedef T                                                          mapped_type;
318    typedef Hash                                                       hasher;
319    typedef Pred                                                       key_equal;
320    typedef Alloc                                                      allocator_type;
321    typedef pair<const key_type, mapped_type>                          value_type;
322    typedef value_type&                                                reference;
323    typedef const value_type&                                          const_reference;
324    typedef typename allocator_traits<allocator_type>::pointer         pointer;
325    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
326    typedef typename allocator_traits<allocator_type>::size_type       size_type;
327    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
328
329    typedef /unspecified/ iterator;
330    typedef /unspecified/ const_iterator;
331    typedef /unspecified/ local_iterator;
332    typedef /unspecified/ const_local_iterator;
333
334    typedef unspecified node_type;    // C++17
335
336    unordered_multimap()
337        noexcept(
338            is_nothrow_default_constructible<hasher>::value &&
339            is_nothrow_default_constructible<key_equal>::value &&
340            is_nothrow_default_constructible<allocator_type>::value);
341    explicit unordered_multimap(size_type n, const hasher& hf = hasher(),
342                           const key_equal& eql = key_equal(),
343                           const allocator_type& a = allocator_type());
344    template <class InputIterator>
345        unordered_multimap(InputIterator f, InputIterator l,
346                      size_type n = 0, const hasher& hf = hasher(),
347                      const key_equal& eql = key_equal(),
348                      const allocator_type& a = allocator_type());
349    template<container-compatible-range<value_type> R>
350      unordered_multimap(from_range_t, R&& rg, size_type n = see below,
351        const hasher& hf = hasher(), const key_equal& eql = key_equal(),
352        const allocator_type& a = allocator_type()); // C++23
353    explicit unordered_multimap(const allocator_type&);
354    unordered_multimap(const unordered_multimap&);
355    unordered_multimap(const unordered_multimap&, const Allocator&);
356    unordered_multimap(unordered_multimap&&)
357        noexcept(
358            is_nothrow_move_constructible<hasher>::value &&
359            is_nothrow_move_constructible<key_equal>::value &&
360            is_nothrow_move_constructible<allocator_type>::value);
361    unordered_multimap(unordered_multimap&&, const Allocator&);
362    unordered_multimap(initializer_list<value_type>, size_type n = 0,
363                  const hasher& hf = hasher(), const key_equal& eql = key_equal(),
364                  const allocator_type& a = allocator_type());
365    unordered_multimap(size_type n, const allocator_type& a)
366      : unordered_multimap(n, hasher(), key_equal(), a) {}  // C++14
367    unordered_multimap(size_type n, const hasher& hf, const allocator_type& a)
368      : unordered_multimap(n, hf, key_equal(), a) {}  // C++14
369    template <class InputIterator>
370      unordered_multimap(InputIterator f, InputIterator l, size_type n, const allocator_type& a)
371      : unordered_multimap(f, l, n, hasher(), key_equal(), a) {}  // C++14
372    template <class InputIterator>
373      unordered_multimap(InputIterator f, InputIterator l, size_type n, const hasher& hf,
374        const allocator_type& a)
375      : unordered_multimap(f, l, n, hf, key_equal(), a) {}  // C++14
376    template<container-compatible-range<value_type> R>
377      unordered_multimap(from_range_t, R&& rg, size_type n, const allocator_type& a)
378        : unordered_multimap(from_range, std::forward<R>(rg), n, hasher(), key_equal(), a) { } // C++23
379    template<container-compatible-range<value_type> R>
380      unordered_multimap(from_range_t, R&& rg, size_type n, const hasher& hf, const allocator_type& a)
381        : unordered_multimap(from_range, std::forward<R>(rg), n, hf, key_equal(), a) { }       // C++23
382    unordered_multimap(initializer_list<value_type> il, size_type n, const allocator_type& a)
383      : unordered_multimap(il, n, hasher(), key_equal(), a) {}  // C++14
384    unordered_multimap(initializer_list<value_type> il, size_type n, const hasher& hf,
385      const allocator_type& a)
386      : unordered_multimap(il, n, hf, key_equal(), a) {}  // C++14
387    ~unordered_multimap();
388    unordered_multimap& operator=(const unordered_multimap&);
389    unordered_multimap& operator=(unordered_multimap&&)
390        noexcept(
391            allocator_type::propagate_on_container_move_assignment::value &&
392            is_nothrow_move_assignable<allocator_type>::value &&
393            is_nothrow_move_assignable<hasher>::value &&
394            is_nothrow_move_assignable<key_equal>::value);
395    unordered_multimap& operator=(initializer_list<value_type>);
396
397    allocator_type get_allocator() const noexcept;
398
399    bool      empty() const noexcept;
400    size_type size() const noexcept;
401    size_type max_size() const noexcept;
402
403    iterator       begin() noexcept;
404    iterator       end() noexcept;
405    const_iterator begin()  const noexcept;
406    const_iterator end()    const noexcept;
407    const_iterator cbegin() const noexcept;
408    const_iterator cend()   const noexcept;
409
410    template <class... Args>
411        iterator emplace(Args&&... args);
412    template <class... Args>
413        iterator emplace_hint(const_iterator position, Args&&... args);
414    iterator insert(const value_type& obj);
415    template <class P>
416        iterator insert(P&& obj);
417    iterator insert(const_iterator hint, const value_type& obj);
418    template <class P>
419        iterator insert(const_iterator hint, P&& obj);
420    template <class InputIterator>
421        void insert(InputIterator first, InputIterator last);
422    template<container-compatible-range<value_type> R>
423      void insert_range(R&& rg);                               // C++23
424    void insert(initializer_list<value_type>);
425
426    node_type extract(const_iterator position);                // C++17
427    node_type extract(const key_type& x);                      // C++17
428    iterator insert(node_type&& nh);                           // C++17
429    iterator insert(const_iterator hint, node_type&& nh);      // C++17
430
431    iterator erase(const_iterator position);
432    iterator erase(iterator position);  // C++14
433    size_type erase(const key_type& k);
434    iterator erase(const_iterator first, const_iterator last);
435    void clear() noexcept;
436
437    template<class H2, class P2>
438      void merge(unordered_multimap<Key, T, H2, P2, Allocator>& source);    // C++17
439    template<class H2, class P2>
440      void merge(unordered_multimap<Key, T, H2, P2, Allocator>&& source);   // C++17
441    template<class H2, class P2>
442      void merge(unordered_map<Key, T, H2, P2, Allocator>& source);         // C++17
443    template<class H2, class P2>
444      void merge(unordered_map<Key, T, H2, P2, Allocator>&& source);        // C++17
445
446    void swap(unordered_multimap&)
447        noexcept(
448            (!allocator_type::propagate_on_container_swap::value ||
449             __is_nothrow_swappable<allocator_type>::value) &&
450            __is_nothrow_swappable<hasher>::value &&
451            __is_nothrow_swappable<key_equal>::value);
452
453    hasher hash_function() const;
454    key_equal key_eq() const;
455
456    iterator       find(const key_type& k);
457    const_iterator find(const key_type& k) const;
458    template<typename K>
459        iterator find(const K& x);              // C++20
460    template<typename K>
461        const_iterator find(const K& x) const;  // C++20
462    size_type count(const key_type& k) const;
463    template<typename K>
464        size_type count(const K& k) const; // C++20
465    bool contains(const key_type& k) const; // C++20
466    template<typename K>
467        bool contains(const K& k) const; // C++20
468    pair<iterator, iterator>             equal_range(const key_type& k);
469    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
470    template<typename K>
471        pair<iterator, iterator>             equal_range(const K& k); // C++20
472    template<typename K>
473        pair<const_iterator, const_iterator> equal_range(const K& k) const; // C++20
474
475    size_type bucket_count() const noexcept;
476    size_type max_bucket_count() const noexcept;
477
478    size_type bucket_size(size_type n) const;
479    size_type bucket(const key_type& k) const;
480
481    local_iterator       begin(size_type n);
482    local_iterator       end(size_type n);
483    const_local_iterator begin(size_type n) const;
484    const_local_iterator end(size_type n) const;
485    const_local_iterator cbegin(size_type n) const;
486    const_local_iterator cend(size_type n) const;
487
488    float load_factor() const noexcept;
489    float max_load_factor() const noexcept;
490    void max_load_factor(float z);
491    void rehash(size_type n);
492    void reserve(size_type n);
493};
494
495template<class InputIterator,
496    class Hash = hash<iter_key_t<InputIterator>>, class Pred = equal_to<iter_key_t<InputIterator>>,
497    class Allocator = allocator<iter_to_alloc_t<InputIterator>>>
498unordered_multimap(InputIterator, InputIterator, typename see below::size_type = see below,
499    Hash = Hash(), Pred = Pred(), Allocator = Allocator())
500  -> unordered_multimap<iter_key_t<InputIterator>, iter_value_t<InputIterator>, Hash, Pred,
501    Allocator>; // C++17
502
503template<ranges::input_range R, class Hash = hash<range-key-type<R>>,
504         class Pred = equal_to<range-key-type<R>>,
505         class Allocator = allocator<range-to-alloc-type<R>>>
506  unordered_multimap(from_range_t, R&&, typename see below::size_type = see below,
507                Hash = Hash(), Pred = Pred(), Allocator = Allocator())
508    -> unordered_multimap<range-key-type<R>, range-mapped-type<R>, Hash, Pred, Allocator>; // C++23
509
510template<class Key, class T, class Hash = hash<Key>,
511    class Pred = equal_to<Key>, class Allocator = allocator<pair<const Key, T>>>
512unordered_multimap(initializer_list<pair<const Key, T>>, typename see below::size_type = see below,
513    Hash = Hash(), Pred = Pred(), Allocator = Allocator())
514  -> unordered_multimap<Key, T, Hash, Pred, Allocator>; // C++17
515
516template<class InputIterator, class Allocator>
517unordered_multimap(InputIterator, InputIterator, typename see below::size_type, Allocator)
518  -> unordered_multimap<iter_key_t<InputIterator>, iter_val_t<InputIterator>,
519        hash<iter_key_t<InputIterator>>, equal_to<iter_key_t<InputIterator>>, Allocator>; // C++17
520
521template<class InputIterator, class Allocator>
522unordered_multimap(InputIterator, InputIterator, Allocator)
523  -> unordered_multimap<iter_key_t<InputIterator>, iter_val_t<InputIterator>,
524        hash<iter_key_t<InputIterator>>, equal_to<iter_key_t<InputIterator>>, Allocator>; // C++17
525
526template<class InputIterator, class Hash, class Allocator>
527unordered_multimap(InputIterator, InputIterator, typename see below::size_type, Hash, Allocator)
528  -> unordered_multimap<iter_key_t<InputIterator>, iter_val_t<InputIterator>, Hash,
529          equal_to<iter_key_t<InputIterator>>, Allocator>; // C++17
530
531template<ranges::input_range R, class Allocator>
532  unordered_multimap(from_range_t, R&&, typename see below::size_type, Allocator)
533    -> unordered_multimap<range-key-type<R>, range-mapped-type<R>, hash<range-key-type<R>>,
534                      equal_to<range-key-type<R>>, Allocator>;   // C++23
535
536template<ranges::input_range R, class Allocator>
537  unordered_multimap(from_range_t, R&&, Allocator)
538    -> unordered_multimap<range-key-type<R>, range-mapped-type<R>, hash<range-key-type<R>>,
539                      equal_to<range-key-type<R>>, Allocator>;   // C++23
540
541template<ranges::input_range R, class Hash, class Allocator>
542  unordered_multimap(from_range_t, R&&, typename see below::size_type, Hash, Allocator)
543    -> unordered_multimap<range-key-type<R>, range-mapped-type<R>, Hash,
544                      equal_to<range-key-type<R>>, Allocator>;   // C++23
545
546template<class Key, class T, typename Allocator>
547unordered_multimap(initializer_list<pair<const Key, T>>, typename see below::size_type, Allocator)
548  -> unordered_multimap<Key, T, hash<Key>, equal_to<Key>, Allocator>; // C++17
549
550template<class Key, class T, typename Allocator>
551unordered_multimap(initializer_list<pair<const Key, T>>, Allocator)
552  -> unordered_multimap<Key, T, hash<Key>, equal_to<Key>, Allocator>; // C++17
553
554template<class Key, class T, class Hash, class Allocator>
555unordered_multimap(initializer_list<pair<const Key, T>>, typename see below::size_type, Hash,
556    Allocator)
557  -> unordered_multimap<Key, T, Hash, equal_to<Key>, Allocator>; // C++17
558
559template <class Key, class T, class Hash, class Pred, class Alloc>
560    void swap(unordered_multimap<Key, T, Hash, Pred, Alloc>& x,
561              unordered_multimap<Key, T, Hash, Pred, Alloc>& y)
562              noexcept(noexcept(x.swap(y)));
563
564template <class K, class T, class H, class P, class A, class Predicate>
565    typename unordered_map<K, T, H, P, A>::size_type
566    erase_if(unordered_map<K, T, H, P, A>& c, Predicate pred);       // C++20
567
568template <class K, class T, class H, class P, class A, class Predicate>
569    typename unordered_multimap<K, T, H, P, A>::size_type
570    erase_if(unordered_multimap<K, T, H, P, A>& c, Predicate pred);  // C++20
571
572template <class Key, class T, class Hash, class Pred, class Alloc>
573    bool
574    operator==(const unordered_multimap<Key, T, Hash, Pred, Alloc>& x,
575               const unordered_multimap<Key, T, Hash, Pred, Alloc>& y);
576
577template <class Key, class T, class Hash, class Pred, class Alloc>
578    bool
579    operator!=(const unordered_multimap<Key, T, Hash, Pred, Alloc>& x,
580               const unordered_multimap<Key, T, Hash, Pred, Alloc>& y); // Removed in C++20
581
582}  // std
583
584*/
585
586#include <__algorithm/is_permutation.h>
587#include <__assert> // all public C++ headers provide the assertion handler
588#include <__availability>
589#include <__config>
590#include <__functional/is_transparent.h>
591#include <__functional/operations.h>
592#include <__hash_table>
593#include <__iterator/distance.h>
594#include <__iterator/erase_if_container.h>
595#include <__iterator/iterator_traits.h>
596#include <__iterator/ranges_iterator_traits.h>
597#include <__memory/addressof.h>
598#include <__memory/allocator.h>
599#include <__memory_resource/polymorphic_allocator.h>
600#include <__node_handle>
601#include <__ranges/concepts.h>
602#include <__ranges/container_compatible_range.h>
603#include <__ranges/from_range.h>
604#include <__type_traits/is_allocator.h>
605#include <__type_traits/type_identity.h>
606#include <__utility/forward.h>
607#include <stdexcept>
608#include <tuple>
609#include <version>
610
611// standard-mandated includes
612
613// [iterator.range]
614#include <__iterator/access.h>
615#include <__iterator/data.h>
616#include <__iterator/empty.h>
617#include <__iterator/reverse_access.h>
618#include <__iterator/size.h>
619
620// [unord.map.syn]
621#include <compare>
622#include <initializer_list>
623
624#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
625#  pragma GCC system_header
626#endif
627
628_LIBCPP_PUSH_MACROS
629#include <__undef_macros>
630
631_LIBCPP_BEGIN_NAMESPACE_STD
632
633template <class _Key,
634          class _Cp,
635          class _Hash,
636          class _Pred,
637          bool = is_empty<_Hash>::value && !__libcpp_is_final<_Hash>::value>
638class __unordered_map_hasher : private _Hash {
639public:
640  _LIBCPP_HIDE_FROM_ABI __unordered_map_hasher() _NOEXCEPT_(is_nothrow_default_constructible<_Hash>::value) : _Hash() {}
641  _LIBCPP_HIDE_FROM_ABI __unordered_map_hasher(const _Hash& __h) _NOEXCEPT_(is_nothrow_copy_constructible<_Hash>::value)
642      : _Hash(__h) {}
643  _LIBCPP_HIDE_FROM_ABI const _Hash& hash_function() const _NOEXCEPT { return *this; }
644  _LIBCPP_HIDE_FROM_ABI size_t operator()(const _Cp& __x) const {
645    return static_cast<const _Hash&>(*this)(__x.__get_value().first);
646  }
647  _LIBCPP_HIDE_FROM_ABI size_t operator()(const _Key& __x) const { return static_cast<const _Hash&>(*this)(__x); }
648#if _LIBCPP_STD_VER >= 20
649  template <typename _K2>
650  _LIBCPP_HIDE_FROM_ABI size_t operator()(const _K2& __x) const {
651    return static_cast<const _Hash&>(*this)(__x);
652  }
653#endif
654  _LIBCPP_HIDE_FROM_ABI void swap(__unordered_map_hasher& __y) _NOEXCEPT_(__is_nothrow_swappable<_Hash>::value) {
655    using std::swap;
656    swap(static_cast<_Hash&>(*this), static_cast<_Hash&>(__y));
657  }
658};
659
660template <class _Key, class _Cp, class _Hash, class _Pred>
661class __unordered_map_hasher<_Key, _Cp, _Hash, _Pred, false> {
662  _Hash __hash_;
663
664public:
665  _LIBCPP_HIDE_FROM_ABI __unordered_map_hasher() _NOEXCEPT_(is_nothrow_default_constructible<_Hash>::value)
666      : __hash_() {}
667  _LIBCPP_HIDE_FROM_ABI __unordered_map_hasher(const _Hash& __h) _NOEXCEPT_(is_nothrow_copy_constructible<_Hash>::value)
668      : __hash_(__h) {}
669  _LIBCPP_HIDE_FROM_ABI const _Hash& hash_function() const _NOEXCEPT { return __hash_; }
670  _LIBCPP_HIDE_FROM_ABI size_t operator()(const _Cp& __x) const { return __hash_(__x.__get_value().first); }
671  _LIBCPP_HIDE_FROM_ABI size_t operator()(const _Key& __x) const { return __hash_(__x); }
672#if _LIBCPP_STD_VER >= 20
673  template <typename _K2>
674  _LIBCPP_HIDE_FROM_ABI size_t operator()(const _K2& __x) const {
675    return __hash_(__x);
676  }
677#endif
678  _LIBCPP_HIDE_FROM_ABI void swap(__unordered_map_hasher& __y) _NOEXCEPT_(__is_nothrow_swappable<_Hash>::value) {
679    using std::swap;
680    swap(__hash_, __y.__hash_);
681  }
682};
683
684template <class _Key, class _Cp, class _Hash, class _Pred, bool __b>
685inline _LIBCPP_HIDE_FROM_ABI void
686swap(__unordered_map_hasher<_Key, _Cp, _Hash, _Pred, __b>& __x,
687     __unordered_map_hasher<_Key, _Cp, _Hash, _Pred, __b>& __y) _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) {
688  __x.swap(__y);
689}
690
691template <class _Key,
692          class _Cp,
693          class _Pred,
694          class _Hash,
695          bool = is_empty<_Pred>::value && !__libcpp_is_final<_Pred>::value>
696class __unordered_map_equal : private _Pred {
697public:
698  _LIBCPP_HIDE_FROM_ABI __unordered_map_equal() _NOEXCEPT_(is_nothrow_default_constructible<_Pred>::value) : _Pred() {}
699  _LIBCPP_HIDE_FROM_ABI __unordered_map_equal(const _Pred& __p) _NOEXCEPT_(is_nothrow_copy_constructible<_Pred>::value)
700      : _Pred(__p) {}
701  _LIBCPP_HIDE_FROM_ABI const _Pred& key_eq() const _NOEXCEPT { return *this; }
702  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Cp& __x, const _Cp& __y) const {
703    return static_cast<const _Pred&>(*this)(__x.__get_value().first, __y.__get_value().first);
704  }
705  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Cp& __x, const _Key& __y) const {
706    return static_cast<const _Pred&>(*this)(__x.__get_value().first, __y);
707  }
708  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Key& __x, const _Cp& __y) const {
709    return static_cast<const _Pred&>(*this)(__x, __y.__get_value().first);
710  }
711#if _LIBCPP_STD_VER >= 20
712  template <typename _K2>
713  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Cp& __x, const _K2& __y) const {
714    return static_cast<const _Pred&>(*this)(__x.__get_value().first, __y);
715  }
716  template <typename _K2>
717  _LIBCPP_HIDE_FROM_ABI bool operator()(const _K2& __x, const _Cp& __y) const {
718    return static_cast<const _Pred&>(*this)(__x, __y.__get_value().first);
719  }
720  template <typename _K2>
721  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Key& __x, const _K2& __y) const {
722    return static_cast<const _Pred&>(*this)(__x, __y);
723  }
724  template <typename _K2>
725  _LIBCPP_HIDE_FROM_ABI bool operator()(const _K2& __x, const _Key& __y) const {
726    return static_cast<const _Pred&>(*this)(__x, __y);
727  }
728#endif
729  _LIBCPP_HIDE_FROM_ABI void swap(__unordered_map_equal& __y) _NOEXCEPT_(__is_nothrow_swappable<_Pred>::value) {
730    using std::swap;
731    swap(static_cast<_Pred&>(*this), static_cast<_Pred&>(__y));
732  }
733};
734
735template <class _Key, class _Cp, class _Pred, class _Hash>
736class __unordered_map_equal<_Key, _Cp, _Pred, _Hash, false> {
737  _Pred __pred_;
738
739public:
740  _LIBCPP_HIDE_FROM_ABI __unordered_map_equal() _NOEXCEPT_(is_nothrow_default_constructible<_Pred>::value)
741      : __pred_() {}
742  _LIBCPP_HIDE_FROM_ABI __unordered_map_equal(const _Pred& __p) _NOEXCEPT_(is_nothrow_copy_constructible<_Pred>::value)
743      : __pred_(__p) {}
744  _LIBCPP_HIDE_FROM_ABI const _Pred& key_eq() const _NOEXCEPT { return __pred_; }
745  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Cp& __x, const _Cp& __y) const {
746    return __pred_(__x.__get_value().first, __y.__get_value().first);
747  }
748  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Cp& __x, const _Key& __y) const {
749    return __pred_(__x.__get_value().first, __y);
750  }
751  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Key& __x, const _Cp& __y) const {
752    return __pred_(__x, __y.__get_value().first);
753  }
754#if _LIBCPP_STD_VER >= 20
755  template <typename _K2>
756  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Cp& __x, const _K2& __y) const {
757    return __pred_(__x.__get_value().first, __y);
758  }
759  template <typename _K2>
760  _LIBCPP_HIDE_FROM_ABI bool operator()(const _K2& __x, const _Cp& __y) const {
761    return __pred_(__x, __y.__get_value().first);
762  }
763  template <typename _K2>
764  _LIBCPP_HIDE_FROM_ABI bool operator()(const _Key& __x, const _K2& __y) const {
765    return __pred_(__x, __y);
766  }
767  template <typename _K2>
768  _LIBCPP_HIDE_FROM_ABI bool operator()(const _K2& __x, const _Key& __y) const {
769    return __pred_(__x, __y);
770  }
771#endif
772  _LIBCPP_HIDE_FROM_ABI void swap(__unordered_map_equal& __y) _NOEXCEPT_(__is_nothrow_swappable<_Pred>::value) {
773    using std::swap;
774    swap(__pred_, __y.__pred_);
775  }
776};
777
778template <class _Key, class _Cp, class _Pred, class _Hash, bool __b>
779inline _LIBCPP_HIDE_FROM_ABI void
780swap(__unordered_map_equal<_Key, _Cp, _Pred, _Hash, __b>& __x, __unordered_map_equal<_Key, _Cp, _Pred, _Hash, __b>& __y)
781    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) {
782  __x.swap(__y);
783}
784
785template <class _Alloc>
786class __hash_map_node_destructor {
787  typedef _Alloc allocator_type;
788  typedef allocator_traits<allocator_type> __alloc_traits;
789
790public:
791  typedef typename __alloc_traits::pointer pointer;
792
793private:
794  allocator_type& __na_;
795
796  __hash_map_node_destructor& operator=(const __hash_map_node_destructor&);
797
798public:
799  bool __first_constructed;
800  bool __second_constructed;
801
802  _LIBCPP_HIDE_FROM_ABI explicit __hash_map_node_destructor(allocator_type& __na) _NOEXCEPT
803      : __na_(__na),
804        __first_constructed(false),
805        __second_constructed(false) {}
806
807#ifndef _LIBCPP_CXX03_LANG
808  _LIBCPP_HIDE_FROM_ABI __hash_map_node_destructor(__hash_node_destructor<allocator_type>&& __x) _NOEXCEPT
809      : __na_(__x.__na_),
810        __first_constructed(__x.__value_constructed),
811        __second_constructed(__x.__value_constructed) {
812    __x.__value_constructed = false;
813  }
814#else  // _LIBCPP_CXX03_LANG
815  _LIBCPP_HIDE_FROM_ABI __hash_map_node_destructor(const __hash_node_destructor<allocator_type>& __x)
816      : __na_(__x.__na_), __first_constructed(__x.__value_constructed), __second_constructed(__x.__value_constructed) {
817    const_cast<bool&>(__x.__value_constructed) = false;
818  }
819#endif // _LIBCPP_CXX03_LANG
820
821  _LIBCPP_HIDE_FROM_ABI void operator()(pointer __p) _NOEXCEPT {
822    if (__second_constructed)
823      __alloc_traits::destroy(__na_, std::addressof(__p->__get_value().__get_value().second));
824    if (__first_constructed)
825      __alloc_traits::destroy(__na_, std::addressof(__p->__get_value().__get_value().first));
826    if (__p)
827      __alloc_traits::deallocate(__na_, __p, 1);
828  }
829};
830
831#ifndef _LIBCPP_CXX03_LANG
832template <class _Key, class _Tp>
833struct _LIBCPP_STANDALONE_DEBUG __hash_value_type {
834  typedef _Key key_type;
835  typedef _Tp mapped_type;
836  typedef pair<const key_type, mapped_type> value_type;
837  typedef pair<key_type&, mapped_type&> __nc_ref_pair_type;
838  typedef pair<key_type&&, mapped_type&&> __nc_rref_pair_type;
839
840private:
841  value_type __cc_;
842
843public:
844  _LIBCPP_HIDE_FROM_ABI value_type& __get_value() {
845#  if _LIBCPP_STD_VER >= 17
846    return *std::launder(std::addressof(__cc_));
847#  else
848    return __cc_;
849#  endif
850  }
851
852  _LIBCPP_HIDE_FROM_ABI const value_type& __get_value() const {
853#  if _LIBCPP_STD_VER >= 17
854    return *std::launder(std::addressof(__cc_));
855#  else
856    return __cc_;
857#  endif
858  }
859
860  _LIBCPP_HIDE_FROM_ABI __nc_ref_pair_type __ref() {
861    value_type& __v = __get_value();
862    return __nc_ref_pair_type(const_cast<key_type&>(__v.first), __v.second);
863  }
864
865  _LIBCPP_HIDE_FROM_ABI __nc_rref_pair_type __move() {
866    value_type& __v = __get_value();
867    return __nc_rref_pair_type(std::move(const_cast<key_type&>(__v.first)), std::move(__v.second));
868  }
869
870  _LIBCPP_HIDE_FROM_ABI __hash_value_type& operator=(const __hash_value_type& __v) {
871    __ref() = __v.__get_value();
872    return *this;
873  }
874
875  _LIBCPP_HIDE_FROM_ABI __hash_value_type& operator=(__hash_value_type&& __v) {
876    __ref() = __v.__move();
877    return *this;
878  }
879
880  template <class _ValueTp, class = __enable_if_t<__is_same_uncvref<_ValueTp, value_type>::value> >
881  _LIBCPP_HIDE_FROM_ABI __hash_value_type& operator=(_ValueTp&& __v) {
882    __ref() = std::forward<_ValueTp>(__v);
883    return *this;
884  }
885
886private:
887  __hash_value_type(const __hash_value_type& __v) = delete;
888  __hash_value_type(__hash_value_type&& __v)      = delete;
889  template <class... _Args>
890  explicit __hash_value_type(_Args&&... __args) = delete;
891
892  ~__hash_value_type() = delete;
893};
894
895#else
896
897template <class _Key, class _Tp>
898struct __hash_value_type {
899  typedef _Key key_type;
900  typedef _Tp mapped_type;
901  typedef pair<const key_type, mapped_type> value_type;
902
903private:
904  value_type __cc_;
905
906public:
907  _LIBCPP_HIDE_FROM_ABI value_type& __get_value() { return __cc_; }
908  _LIBCPP_HIDE_FROM_ABI const value_type& __get_value() const { return __cc_; }
909
910private:
911  ~__hash_value_type();
912};
913
914#endif
915
916template <class _HashIterator>
917class _LIBCPP_TEMPLATE_VIS __hash_map_iterator {
918  _HashIterator __i_;
919
920  typedef __hash_node_types_from_iterator<_HashIterator> _NodeTypes;
921
922public:
923  typedef forward_iterator_tag iterator_category;
924  typedef typename _NodeTypes::__map_value_type value_type;
925  typedef typename _NodeTypes::difference_type difference_type;
926  typedef value_type& reference;
927  typedef typename _NodeTypes::__map_value_type_pointer pointer;
928
929  _LIBCPP_HIDE_FROM_ABI __hash_map_iterator() _NOEXCEPT {}
930
931  _LIBCPP_HIDE_FROM_ABI __hash_map_iterator(_HashIterator __i) _NOEXCEPT : __i_(__i) {}
932
933  _LIBCPP_HIDE_FROM_ABI reference operator*() const { return __i_->__get_value(); }
934  _LIBCPP_HIDE_FROM_ABI pointer operator->() const { return pointer_traits<pointer>::pointer_to(__i_->__get_value()); }
935
936  _LIBCPP_HIDE_FROM_ABI __hash_map_iterator& operator++() {
937    ++__i_;
938    return *this;
939  }
940  _LIBCPP_HIDE_FROM_ABI __hash_map_iterator operator++(int) {
941    __hash_map_iterator __t(*this);
942    ++(*this);
943    return __t;
944  }
945
946  friend _LIBCPP_HIDE_FROM_ABI bool operator==(const __hash_map_iterator& __x, const __hash_map_iterator& __y) {
947    return __x.__i_ == __y.__i_;
948  }
949#if _LIBCPP_STD_VER <= 17
950  friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const __hash_map_iterator& __x, const __hash_map_iterator& __y) {
951    return __x.__i_ != __y.__i_;
952  }
953#endif
954
955  template <class, class, class, class, class>
956  friend class _LIBCPP_TEMPLATE_VIS unordered_map;
957  template <class, class, class, class, class>
958  friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
959  template <class>
960  friend class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
961  template <class>
962  friend class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
963  template <class>
964  friend class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
965};
966
967template <class _HashIterator>
968class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator {
969  _HashIterator __i_;
970
971  typedef __hash_node_types_from_iterator<_HashIterator> _NodeTypes;
972
973public:
974  typedef forward_iterator_tag iterator_category;
975  typedef typename _NodeTypes::__map_value_type value_type;
976  typedef typename _NodeTypes::difference_type difference_type;
977  typedef const value_type& reference;
978  typedef typename _NodeTypes::__const_map_value_type_pointer pointer;
979
980  _LIBCPP_HIDE_FROM_ABI __hash_map_const_iterator() _NOEXCEPT {}
981
982  _LIBCPP_HIDE_FROM_ABI __hash_map_const_iterator(_HashIterator __i) _NOEXCEPT : __i_(__i) {}
983  _LIBCPP_HIDE_FROM_ABI
984  __hash_map_const_iterator(__hash_map_iterator<typename _HashIterator::__non_const_iterator> __i) _NOEXCEPT
985      : __i_(__i.__i_) {}
986
987  _LIBCPP_HIDE_FROM_ABI reference operator*() const { return __i_->__get_value(); }
988  _LIBCPP_HIDE_FROM_ABI pointer operator->() const { return pointer_traits<pointer>::pointer_to(__i_->__get_value()); }
989
990  _LIBCPP_HIDE_FROM_ABI __hash_map_const_iterator& operator++() {
991    ++__i_;
992    return *this;
993  }
994  _LIBCPP_HIDE_FROM_ABI __hash_map_const_iterator operator++(int) {
995    __hash_map_const_iterator __t(*this);
996    ++(*this);
997    return __t;
998  }
999
1000  friend _LIBCPP_HIDE_FROM_ABI bool
1001  operator==(const __hash_map_const_iterator& __x, const __hash_map_const_iterator& __y) {
1002    return __x.__i_ == __y.__i_;
1003  }
1004#if _LIBCPP_STD_VER <= 17
1005  friend _LIBCPP_HIDE_FROM_ABI bool
1006  operator!=(const __hash_map_const_iterator& __x, const __hash_map_const_iterator& __y) {
1007    return __x.__i_ != __y.__i_;
1008  }
1009#endif
1010
1011  template <class, class, class, class, class>
1012  friend class _LIBCPP_TEMPLATE_VIS unordered_map;
1013  template <class, class, class, class, class>
1014  friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
1015  template <class>
1016  friend class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
1017  template <class>
1018  friend class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
1019};
1020
1021template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1022class unordered_multimap;
1023
1024template <class _Key,
1025          class _Tp,
1026          class _Hash  = hash<_Key>,
1027          class _Pred  = equal_to<_Key>,
1028          class _Alloc = allocator<pair<const _Key, _Tp> > >
1029class _LIBCPP_TEMPLATE_VIS unordered_map {
1030public:
1031  // types
1032  typedef _Key key_type;
1033  typedef _Tp mapped_type;
1034  typedef __type_identity_t<_Hash> hasher;
1035  typedef __type_identity_t<_Pred> key_equal;
1036  typedef __type_identity_t<_Alloc> allocator_type;
1037  typedef pair<const key_type, mapped_type> value_type;
1038  typedef value_type& reference;
1039  typedef const value_type& const_reference;
1040  static_assert((is_same<value_type, typename allocator_type::value_type>::value),
1041                "Allocator::value_type must be same type as value_type");
1042
1043private:
1044  typedef __hash_value_type<key_type, mapped_type> __value_type;
1045  typedef __unordered_map_hasher<key_type, __value_type, hasher, key_equal> __hasher;
1046  typedef __unordered_map_equal<key_type, __value_type, key_equal, hasher> __key_equal;
1047  typedef __rebind_alloc<allocator_traits<allocator_type>, __value_type> __allocator_type;
1048
1049  typedef __hash_table<__value_type, __hasher, __key_equal, __allocator_type> __table;
1050
1051  __table __table_;
1052
1053  typedef typename __table::_NodeTypes _NodeTypes;
1054  typedef typename __table::__node_pointer __node_pointer;
1055  typedef typename __table::__node_const_pointer __node_const_pointer;
1056  typedef typename __table::__node_traits __node_traits;
1057  typedef typename __table::__node_allocator __node_allocator;
1058  typedef typename __table::__node __node;
1059  typedef __hash_map_node_destructor<__node_allocator> _Dp;
1060  typedef unique_ptr<__node, _Dp> __node_holder;
1061  typedef allocator_traits<allocator_type> __alloc_traits;
1062
1063  static_assert(is_same<allocator_type, __rebind_alloc<__alloc_traits, value_type> >::value,
1064                "[allocator.requirements] states that rebinding an allocator to the same type should result in the "
1065                "original allocator");
1066
1067  static_assert((is_same<typename __table::__container_value_type, value_type>::value), "");
1068  static_assert((is_same<typename __table::__node_value_type, __value_type>::value), "");
1069
1070public:
1071  typedef typename __alloc_traits::pointer pointer;
1072  typedef typename __alloc_traits::const_pointer const_pointer;
1073  typedef typename __table::size_type size_type;
1074  typedef typename __table::difference_type difference_type;
1075
1076  typedef __hash_map_iterator<typename __table::iterator> iterator;
1077  typedef __hash_map_const_iterator<typename __table::const_iterator> const_iterator;
1078  typedef __hash_map_iterator<typename __table::local_iterator> local_iterator;
1079  typedef __hash_map_const_iterator<typename __table::const_local_iterator> const_local_iterator;
1080
1081#if _LIBCPP_STD_VER >= 17
1082  typedef __map_node_handle<__node, allocator_type> node_type;
1083  typedef __insert_return_type<iterator, node_type> insert_return_type;
1084#endif
1085
1086  template <class _Key2, class _Tp2, class _Hash2, class _Pred2, class _Alloc2>
1087  friend class _LIBCPP_TEMPLATE_VIS unordered_map;
1088  template <class _Key2, class _Tp2, class _Hash2, class _Pred2, class _Alloc2>
1089  friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
1090
1091  _LIBCPP_HIDE_FROM_ABI unordered_map() _NOEXCEPT_(is_nothrow_default_constructible<__table>::value) {}
1092  explicit _LIBCPP_HIDE_FROM_ABI
1093  unordered_map(size_type __n, const hasher& __hf = hasher(), const key_equal& __eql = key_equal());
1094  _LIBCPP_HIDE_FROM_ABI
1095  unordered_map(size_type __n, const hasher& __hf, const key_equal& __eql, const allocator_type& __a);
1096  template <class _InputIterator>
1097  _LIBCPP_HIDE_FROM_ABI unordered_map(_InputIterator __first, _InputIterator __last);
1098  template <class _InputIterator>
1099  _LIBCPP_HIDE_FROM_ABI
1100  unordered_map(_InputIterator __first,
1101                _InputIterator __last,
1102                size_type __n,
1103                const hasher& __hf     = hasher(),
1104                const key_equal& __eql = key_equal());
1105  template <class _InputIterator>
1106  _LIBCPP_HIDE_FROM_ABI unordered_map(
1107      _InputIterator __first,
1108      _InputIterator __last,
1109      size_type __n,
1110      const hasher& __hf,
1111      const key_equal& __eql,
1112      const allocator_type& __a);
1113
1114#if _LIBCPP_STD_VER >= 23
1115  template <_ContainerCompatibleRange<value_type> _Range>
1116  _LIBCPP_HIDE_FROM_ABI unordered_map(
1117      from_range_t,
1118      _Range&& __range,
1119      size_type __n             = /*implementation-defined*/ 0,
1120      const hasher& __hf        = hasher(),
1121      const key_equal& __eql    = key_equal(),
1122      const allocator_type& __a = allocator_type())
1123      : __table_(__hf, __eql, typename __table::allocator_type(__a)) {
1124    if (__n > 0) {
1125      __table_.__rehash_unique(__n);
1126    }
1127    insert_range(std::forward<_Range>(__range));
1128  }
1129#endif
1130
1131  _LIBCPP_HIDE_FROM_ABI explicit unordered_map(const allocator_type& __a);
1132  _LIBCPP_HIDE_FROM_ABI unordered_map(const unordered_map& __u);
1133  _LIBCPP_HIDE_FROM_ABI unordered_map(const unordered_map& __u, const allocator_type& __a);
1134#ifndef _LIBCPP_CXX03_LANG
1135  _LIBCPP_HIDE_FROM_ABI unordered_map(unordered_map&& __u) _NOEXCEPT_(is_nothrow_move_constructible<__table>::value);
1136  _LIBCPP_HIDE_FROM_ABI unordered_map(unordered_map&& __u, const allocator_type& __a);
1137  _LIBCPP_HIDE_FROM_ABI unordered_map(initializer_list<value_type> __il);
1138  _LIBCPP_HIDE_FROM_ABI
1139  unordered_map(initializer_list<value_type> __il,
1140                size_type __n,
1141                const hasher& __hf     = hasher(),
1142                const key_equal& __eql = key_equal());
1143  _LIBCPP_HIDE_FROM_ABI unordered_map(
1144      initializer_list<value_type> __il,
1145      size_type __n,
1146      const hasher& __hf,
1147      const key_equal& __eql,
1148      const allocator_type& __a);
1149#endif // _LIBCPP_CXX03_LANG
1150#if _LIBCPP_STD_VER >= 14
1151  _LIBCPP_HIDE_FROM_ABI unordered_map(size_type __n, const allocator_type& __a)
1152      : unordered_map(__n, hasher(), key_equal(), __a) {}
1153  _LIBCPP_HIDE_FROM_ABI unordered_map(size_type __n, const hasher& __hf, const allocator_type& __a)
1154      : unordered_map(__n, __hf, key_equal(), __a) {}
1155  template <class _InputIterator>
1156  _LIBCPP_HIDE_FROM_ABI
1157  unordered_map(_InputIterator __first, _InputIterator __last, size_type __n, const allocator_type& __a)
1158      : unordered_map(__first, __last, __n, hasher(), key_equal(), __a) {}
1159  template <class _InputIterator>
1160  _LIBCPP_HIDE_FROM_ABI unordered_map(
1161      _InputIterator __first, _InputIterator __last, size_type __n, const hasher& __hf, const allocator_type& __a)
1162      : unordered_map(__first, __last, __n, __hf, key_equal(), __a) {}
1163
1164#  if _LIBCPP_STD_VER >= 23
1165  template <_ContainerCompatibleRange<value_type> _Range>
1166  _LIBCPP_HIDE_FROM_ABI unordered_map(from_range_t, _Range&& __range, size_type __n, const allocator_type& __a)
1167      : unordered_map(from_range, std::forward<_Range>(__range), __n, hasher(), key_equal(), __a) {}
1168
1169  template <_ContainerCompatibleRange<value_type> _Range>
1170  _LIBCPP_HIDE_FROM_ABI
1171  unordered_map(from_range_t, _Range&& __range, size_type __n, const hasher& __hf, const allocator_type& __a)
1172      : unordered_map(from_range, std::forward<_Range>(__range), __n, __hf, key_equal(), __a) {}
1173#  endif
1174
1175  _LIBCPP_HIDE_FROM_ABI unordered_map(initializer_list<value_type> __il, size_type __n, const allocator_type& __a)
1176      : unordered_map(__il, __n, hasher(), key_equal(), __a) {}
1177  _LIBCPP_HIDE_FROM_ABI
1178  unordered_map(initializer_list<value_type> __il, size_type __n, const hasher& __hf, const allocator_type& __a)
1179      : unordered_map(__il, __n, __hf, key_equal(), __a) {}
1180#endif
1181  _LIBCPP_HIDE_FROM_ABI ~unordered_map() {
1182    static_assert(sizeof(std::__diagnose_unordered_container_requirements<_Key, _Hash, _Pred>(0)), "");
1183  }
1184
1185  _LIBCPP_HIDE_FROM_ABI unordered_map& operator=(const unordered_map& __u) {
1186#ifndef _LIBCPP_CXX03_LANG
1187    __table_ = __u.__table_;
1188#else
1189    if (this != std::addressof(__u)) {
1190      __table_.clear();
1191      __table_.hash_function()   = __u.__table_.hash_function();
1192      __table_.key_eq()          = __u.__table_.key_eq();
1193      __table_.max_load_factor() = __u.__table_.max_load_factor();
1194      __table_.__copy_assign_alloc(__u.__table_);
1195      insert(__u.begin(), __u.end());
1196    }
1197#endif
1198    return *this;
1199  }
1200#ifndef _LIBCPP_CXX03_LANG
1201  _LIBCPP_HIDE_FROM_ABI unordered_map& operator=(unordered_map&& __u)
1202      _NOEXCEPT_(is_nothrow_move_assignable<__table>::value);
1203  _LIBCPP_HIDE_FROM_ABI unordered_map& operator=(initializer_list<value_type> __il);
1204#endif // _LIBCPP_CXX03_LANG
1205
1206  _LIBCPP_HIDE_FROM_ABI allocator_type get_allocator() const _NOEXCEPT {
1207    return allocator_type(__table_.__node_alloc());
1208  }
1209
1210  _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI bool empty() const _NOEXCEPT { return __table_.size() == 0; }
1211  _LIBCPP_HIDE_FROM_ABI size_type size() const _NOEXCEPT { return __table_.size(); }
1212  _LIBCPP_HIDE_FROM_ABI size_type max_size() const _NOEXCEPT { return __table_.max_size(); }
1213
1214  _LIBCPP_HIDE_FROM_ABI iterator begin() _NOEXCEPT { return __table_.begin(); }
1215  _LIBCPP_HIDE_FROM_ABI iterator end() _NOEXCEPT { return __table_.end(); }
1216  _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT { return __table_.begin(); }
1217  _LIBCPP_HIDE_FROM_ABI const_iterator end() const _NOEXCEPT { return __table_.end(); }
1218  _LIBCPP_HIDE_FROM_ABI const_iterator cbegin() const _NOEXCEPT { return __table_.begin(); }
1219  _LIBCPP_HIDE_FROM_ABI const_iterator cend() const _NOEXCEPT { return __table_.end(); }
1220
1221  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert(const value_type& __x) { return __table_.__insert_unique(__x); }
1222
1223  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator, const value_type& __x) { return insert(__x).first; }
1224
1225  template <class _InputIterator>
1226  _LIBCPP_HIDE_FROM_ABI void insert(_InputIterator __first, _InputIterator __last);
1227
1228#if _LIBCPP_STD_VER >= 23
1229  template <_ContainerCompatibleRange<value_type> _Range>
1230  _LIBCPP_HIDE_FROM_ABI void insert_range(_Range&& __range) {
1231    for (auto&& __element : __range) {
1232      __table_.__insert_unique(std::forward<decltype(__element)>(__element));
1233    }
1234  }
1235#endif
1236
1237#ifndef _LIBCPP_CXX03_LANG
1238  _LIBCPP_HIDE_FROM_ABI void insert(initializer_list<value_type> __il) { insert(__il.begin(), __il.end()); }
1239
1240  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert(value_type&& __x) {
1241    return __table_.__insert_unique(std::move(__x));
1242  }
1243
1244  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator, value_type&& __x) {
1245    return __table_.__insert_unique(std::move(__x)).first;
1246  }
1247
1248  template <class _Pp, class = __enable_if_t<is_constructible<value_type, _Pp>::value> >
1249  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert(_Pp&& __x) {
1250    return __table_.__insert_unique(std::forward<_Pp>(__x));
1251  }
1252
1253  template <class _Pp, class = __enable_if_t<is_constructible<value_type, _Pp>::value> >
1254  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator, _Pp&& __x) {
1255    return insert(std::forward<_Pp>(__x)).first;
1256  }
1257
1258  template <class... _Args>
1259  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> emplace(_Args&&... __args) {
1260    return __table_.__emplace_unique(std::forward<_Args>(__args)...);
1261  }
1262
1263  template <class... _Args>
1264  _LIBCPP_HIDE_FROM_ABI iterator emplace_hint(const_iterator, _Args&&... __args) {
1265    return __table_.__emplace_unique(std::forward<_Args>(__args)...).first;
1266  }
1267
1268#endif // _LIBCPP_CXX03_LANG
1269
1270#if _LIBCPP_STD_VER >= 17
1271  template <class... _Args>
1272  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> try_emplace(const key_type& __k, _Args&&... __args) {
1273    return __table_.__emplace_unique_key_args(
1274        __k, piecewise_construct, std::forward_as_tuple(__k), std::forward_as_tuple(std::forward<_Args>(__args)...));
1275  }
1276
1277  template <class... _Args>
1278  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> try_emplace(key_type&& __k, _Args&&... __args) {
1279    return __table_.__emplace_unique_key_args(
1280        __k,
1281        piecewise_construct,
1282        std::forward_as_tuple(std::move(__k)),
1283        std::forward_as_tuple(std::forward<_Args>(__args)...));
1284  }
1285
1286  template <class... _Args>
1287  _LIBCPP_HIDE_FROM_ABI iterator try_emplace(const_iterator, const key_type& __k, _Args&&... __args) {
1288    return try_emplace(__k, std::forward<_Args>(__args)...).first;
1289  }
1290
1291  template <class... _Args>
1292  _LIBCPP_HIDE_FROM_ABI iterator try_emplace(const_iterator, key_type&& __k, _Args&&... __args) {
1293    return try_emplace(std::move(__k), std::forward<_Args>(__args)...).first;
1294  }
1295
1296  template <class _Vp>
1297  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert_or_assign(const key_type& __k, _Vp&& __v) {
1298    pair<iterator, bool> __res = __table_.__emplace_unique_key_args(__k, __k, std::forward<_Vp>(__v));
1299    if (!__res.second) {
1300      __res.first->second = std::forward<_Vp>(__v);
1301    }
1302    return __res;
1303  }
1304
1305  template <class _Vp>
1306  _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> insert_or_assign(key_type&& __k, _Vp&& __v) {
1307    pair<iterator, bool> __res = __table_.__emplace_unique_key_args(__k, std::move(__k), std::forward<_Vp>(__v));
1308    if (!__res.second) {
1309      __res.first->second = std::forward<_Vp>(__v);
1310    }
1311    return __res;
1312  }
1313
1314  template <class _Vp>
1315  _LIBCPP_HIDE_FROM_ABI iterator insert_or_assign(const_iterator, const key_type& __k, _Vp&& __v) {
1316    return insert_or_assign(__k, std::forward<_Vp>(__v)).first;
1317  }
1318
1319  template <class _Vp>
1320  _LIBCPP_HIDE_FROM_ABI iterator insert_or_assign(const_iterator, key_type&& __k, _Vp&& __v) {
1321    return insert_or_assign(std::move(__k), std::forward<_Vp>(__v)).first;
1322  }
1323#endif // _LIBCPP_STD_VER >= 17
1324
1325  _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __p) { return __table_.erase(__p.__i_); }
1326  _LIBCPP_HIDE_FROM_ABI iterator erase(iterator __p) { return __table_.erase(__p.__i_); }
1327  _LIBCPP_HIDE_FROM_ABI size_type erase(const key_type& __k) { return __table_.__erase_unique(__k); }
1328  _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __first, const_iterator __last) {
1329    return __table_.erase(__first.__i_, __last.__i_);
1330  }
1331  _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT { __table_.clear(); }
1332
1333#if _LIBCPP_STD_VER >= 17
1334  _LIBCPP_HIDE_FROM_ABI insert_return_type insert(node_type&& __nh) {
1335    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(__nh.empty() || __nh.get_allocator() == get_allocator(),
1336                                        "node_type with incompatible allocator passed to unordered_map::insert()");
1337    return __table_.template __node_handle_insert_unique< node_type, insert_return_type>(std::move(__nh));
1338  }
1339  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __hint, node_type&& __nh) {
1340    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(__nh.empty() || __nh.get_allocator() == get_allocator(),
1341                                        "node_type with incompatible allocator passed to unordered_map::insert()");
1342    return __table_.template __node_handle_insert_unique<node_type>(__hint.__i_, std::move(__nh));
1343  }
1344  _LIBCPP_HIDE_FROM_ABI node_type extract(key_type const& __key) {
1345    return __table_.template __node_handle_extract<node_type>(__key);
1346  }
1347  _LIBCPP_HIDE_FROM_ABI node_type extract(const_iterator __it) {
1348    return __table_.template __node_handle_extract<node_type>(__it.__i_);
1349  }
1350
1351  template <class _H2, class _P2>
1352  _LIBCPP_HIDE_FROM_ABI void merge(unordered_map<key_type, mapped_type, _H2, _P2, allocator_type>& __source) {
1353    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
1354        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
1355    return __table_.__node_handle_merge_unique(__source.__table_);
1356  }
1357  template <class _H2, class _P2>
1358  _LIBCPP_HIDE_FROM_ABI void merge(unordered_map<key_type, mapped_type, _H2, _P2, allocator_type>&& __source) {
1359    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
1360        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
1361    return __table_.__node_handle_merge_unique(__source.__table_);
1362  }
1363  template <class _H2, class _P2>
1364  _LIBCPP_HIDE_FROM_ABI void merge(unordered_multimap<key_type, mapped_type, _H2, _P2, allocator_type>& __source) {
1365    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
1366        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
1367    return __table_.__node_handle_merge_unique(__source.__table_);
1368  }
1369  template <class _H2, class _P2>
1370  _LIBCPP_HIDE_FROM_ABI void merge(unordered_multimap<key_type, mapped_type, _H2, _P2, allocator_type>&& __source) {
1371    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
1372        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
1373    return __table_.__node_handle_merge_unique(__source.__table_);
1374  }
1375#endif
1376
1377  _LIBCPP_HIDE_FROM_ABI void swap(unordered_map& __u) _NOEXCEPT_(__is_nothrow_swappable<__table>::value) {
1378    __table_.swap(__u.__table_);
1379  }
1380
1381  _LIBCPP_HIDE_FROM_ABI hasher hash_function() const { return __table_.hash_function().hash_function(); }
1382  _LIBCPP_HIDE_FROM_ABI key_equal key_eq() const { return __table_.key_eq().key_eq(); }
1383
1384  _LIBCPP_HIDE_FROM_ABI iterator find(const key_type& __k) { return __table_.find(__k); }
1385  _LIBCPP_HIDE_FROM_ABI const_iterator find(const key_type& __k) const { return __table_.find(__k); }
1386#if _LIBCPP_STD_VER >= 20
1387  template <class _K2,
1388            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1389  _LIBCPP_HIDE_FROM_ABI iterator find(const _K2& __k) {
1390    return __table_.find(__k);
1391  }
1392  template <class _K2,
1393            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1394  _LIBCPP_HIDE_FROM_ABI const_iterator find(const _K2& __k) const {
1395    return __table_.find(__k);
1396  }
1397#endif // _LIBCPP_STD_VER >= 20
1398
1399  _LIBCPP_HIDE_FROM_ABI size_type count(const key_type& __k) const { return __table_.__count_unique(__k); }
1400#if _LIBCPP_STD_VER >= 20
1401  template <class _K2,
1402            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1403  _LIBCPP_HIDE_FROM_ABI size_type count(const _K2& __k) const {
1404    return __table_.__count_unique(__k);
1405  }
1406#endif // _LIBCPP_STD_VER >= 20
1407
1408#if _LIBCPP_STD_VER >= 20
1409  _LIBCPP_HIDE_FROM_ABI bool contains(const key_type& __k) const { return find(__k) != end(); }
1410
1411  template <class _K2,
1412            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1413  _LIBCPP_HIDE_FROM_ABI bool contains(const _K2& __k) const {
1414    return find(__k) != end();
1415  }
1416#endif // _LIBCPP_STD_VER >= 20
1417
1418  _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> equal_range(const key_type& __k) {
1419    return __table_.__equal_range_unique(__k);
1420  }
1421  _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator> equal_range(const key_type& __k) const {
1422    return __table_.__equal_range_unique(__k);
1423  }
1424#if _LIBCPP_STD_VER >= 20
1425  template <class _K2,
1426            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1427  _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> equal_range(const _K2& __k) {
1428    return __table_.__equal_range_unique(__k);
1429  }
1430  template <class _K2,
1431            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
1432  _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator> equal_range(const _K2& __k) const {
1433    return __table_.__equal_range_unique(__k);
1434  }
1435#endif // _LIBCPP_STD_VER >= 20
1436
1437  _LIBCPP_HIDE_FROM_ABI mapped_type& operator[](const key_type& __k);
1438#ifndef _LIBCPP_CXX03_LANG
1439  _LIBCPP_HIDE_FROM_ABI mapped_type& operator[](key_type&& __k);
1440#endif
1441
1442  _LIBCPP_HIDE_FROM_ABI mapped_type& at(const key_type& __k);
1443  _LIBCPP_HIDE_FROM_ABI const mapped_type& at(const key_type& __k) const;
1444
1445  _LIBCPP_HIDE_FROM_ABI size_type bucket_count() const _NOEXCEPT { return __table_.bucket_count(); }
1446  _LIBCPP_HIDE_FROM_ABI size_type max_bucket_count() const _NOEXCEPT { return __table_.max_bucket_count(); }
1447
1448  _LIBCPP_HIDE_FROM_ABI size_type bucket_size(size_type __n) const { return __table_.bucket_size(__n); }
1449  _LIBCPP_HIDE_FROM_ABI size_type bucket(const key_type& __k) const { return __table_.bucket(__k); }
1450
1451  _LIBCPP_HIDE_FROM_ABI local_iterator begin(size_type __n) { return __table_.begin(__n); }
1452  _LIBCPP_HIDE_FROM_ABI local_iterator end(size_type __n) { return __table_.end(__n); }
1453  _LIBCPP_HIDE_FROM_ABI const_local_iterator begin(size_type __n) const { return __table_.cbegin(__n); }
1454  _LIBCPP_HIDE_FROM_ABI const_local_iterator end(size_type __n) const { return __table_.cend(__n); }
1455  _LIBCPP_HIDE_FROM_ABI const_local_iterator cbegin(size_type __n) const { return __table_.cbegin(__n); }
1456  _LIBCPP_HIDE_FROM_ABI const_local_iterator cend(size_type __n) const { return __table_.cend(__n); }
1457
1458  _LIBCPP_HIDE_FROM_ABI float load_factor() const _NOEXCEPT { return __table_.load_factor(); }
1459  _LIBCPP_HIDE_FROM_ABI float max_load_factor() const _NOEXCEPT { return __table_.max_load_factor(); }
1460  _LIBCPP_HIDE_FROM_ABI void max_load_factor(float __mlf) { __table_.max_load_factor(__mlf); }
1461  _LIBCPP_HIDE_FROM_ABI void rehash(size_type __n) { __table_.__rehash_unique(__n); }
1462  _LIBCPP_HIDE_FROM_ABI void reserve(size_type __n) { __table_.__reserve_unique(__n); }
1463
1464private:
1465#ifdef _LIBCPP_CXX03_LANG
1466  _LIBCPP_HIDE_FROM_ABI __node_holder __construct_node_with_key(const key_type& __k);
1467#endif
1468};
1469
1470#if _LIBCPP_STD_VER >= 17
1471template <class _InputIterator,
1472          class _Hash      = hash<__iter_key_type<_InputIterator>>,
1473          class _Pred      = equal_to<__iter_key_type<_InputIterator>>,
1474          class _Allocator = allocator<__iter_to_alloc_type<_InputIterator>>,
1475          class            = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
1476          class            = enable_if_t<!__is_allocator<_Hash>::value>,
1477          class            = enable_if_t<!is_integral<_Hash>::value>,
1478          class            = enable_if_t<!__is_allocator<_Pred>::value>,
1479          class            = enable_if_t<__is_allocator<_Allocator>::value>>
1480unordered_map(_InputIterator,
1481              _InputIterator,
1482              typename allocator_traits<_Allocator>::size_type = 0,
1483              _Hash                                            = _Hash(),
1484              _Pred                                            = _Pred(),
1485              _Allocator                                       = _Allocator())
1486    -> unordered_map<__iter_key_type<_InputIterator>, __iter_mapped_type<_InputIterator>, _Hash, _Pred, _Allocator>;
1487
1488#  if _LIBCPP_STD_VER >= 23
1489template <ranges::input_range _Range,
1490          class _Hash      = hash<__range_key_type<_Range>>,
1491          class _Pred      = equal_to<__range_key_type<_Range>>,
1492          class _Allocator = allocator<__range_to_alloc_type<_Range>>,
1493          class            = enable_if_t<!__is_allocator<_Hash>::value>,
1494          class            = enable_if_t<!is_integral<_Hash>::value>,
1495          class            = enable_if_t<!__is_allocator<_Pred>::value>,
1496          class            = enable_if_t<__is_allocator<_Allocator>::value>>
1497unordered_map(from_range_t,
1498              _Range&&,
1499              typename allocator_traits<_Allocator>::size_type = 0,
1500              _Hash                                            = _Hash(),
1501              _Pred                                            = _Pred(),
1502              _Allocator                                       = _Allocator())
1503    -> unordered_map<__range_key_type<_Range>, __range_mapped_type<_Range>, _Hash, _Pred, _Allocator>; // C++23
1504#  endif
1505
1506template <class _Key,
1507          class _Tp,
1508          class _Hash      = hash<remove_const_t<_Key>>,
1509          class _Pred      = equal_to<remove_const_t<_Key>>,
1510          class _Allocator = allocator<pair<const _Key, _Tp>>,
1511          class            = enable_if_t<!__is_allocator<_Hash>::value>,
1512          class            = enable_if_t<!is_integral<_Hash>::value>,
1513          class            = enable_if_t<!__is_allocator<_Pred>::value>,
1514          class            = enable_if_t<__is_allocator<_Allocator>::value>>
1515unordered_map(initializer_list<pair<_Key, _Tp>>,
1516              typename allocator_traits<_Allocator>::size_type = 0,
1517              _Hash                                            = _Hash(),
1518              _Pred                                            = _Pred(),
1519              _Allocator = _Allocator()) -> unordered_map<remove_const_t<_Key>, _Tp, _Hash, _Pred, _Allocator>;
1520
1521template <class _InputIterator,
1522          class _Allocator,
1523          class = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
1524          class = enable_if_t<__is_allocator<_Allocator>::value>>
1525unordered_map(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type, _Allocator)
1526    -> unordered_map<__iter_key_type<_InputIterator>,
1527                     __iter_mapped_type<_InputIterator>,
1528                     hash<__iter_key_type<_InputIterator>>,
1529                     equal_to<__iter_key_type<_InputIterator>>,
1530                     _Allocator>;
1531
1532template <class _InputIterator,
1533          class _Allocator,
1534          class = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
1535          class = enable_if_t<__is_allocator<_Allocator>::value>>
1536unordered_map(_InputIterator, _InputIterator, _Allocator)
1537    -> unordered_map<__iter_key_type<_InputIterator>,
1538                     __iter_mapped_type<_InputIterator>,
1539                     hash<__iter_key_type<_InputIterator>>,
1540                     equal_to<__iter_key_type<_InputIterator>>,
1541                     _Allocator>;
1542
1543template <class _InputIterator,
1544          class _Hash,
1545          class _Allocator,
1546          class = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
1547          class = enable_if_t<!__is_allocator<_Hash>::value>,
1548          class = enable_if_t<!is_integral<_Hash>::value>,
1549          class = enable_if_t<__is_allocator<_Allocator>::value>>
1550unordered_map(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
1551    -> unordered_map<__iter_key_type<_InputIterator>,
1552                     __iter_mapped_type<_InputIterator>,
1553                     _Hash,
1554                     equal_to<__iter_key_type<_InputIterator>>,
1555                     _Allocator>;
1556
1557#  if _LIBCPP_STD_VER >= 23
1558
1559template <ranges::input_range _Range, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value>>
1560unordered_map(from_range_t, _Range&&, typename allocator_traits<_Allocator>::size_type, _Allocator)
1561    -> unordered_map<__range_key_type<_Range>,
1562                     __range_mapped_type<_Range>,
1563                     hash<__range_key_type<_Range>>,
1564                     equal_to<__range_key_type<_Range>>,
1565                     _Allocator>;
1566
1567template <ranges::input_range _Range, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value>>
1568unordered_map(from_range_t, _Range&&, _Allocator)
1569    -> unordered_map<__range_key_type<_Range>,
1570                     __range_mapped_type<_Range>,
1571                     hash<__range_key_type<_Range>>,
1572                     equal_to<__range_key_type<_Range>>,
1573                     _Allocator>;
1574
1575template <ranges::input_range _Range,
1576          class _Hash,
1577          class _Allocator,
1578          class = enable_if_t<!__is_allocator<_Hash>::value>,
1579          class = enable_if_t<!is_integral<_Hash>::value>,
1580          class = enable_if_t<__is_allocator<_Allocator>::value>>
1581unordered_map(from_range_t, _Range&&, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
1582    -> unordered_map<__range_key_type<_Range>,
1583                     __range_mapped_type<_Range>,
1584                     _Hash,
1585                     equal_to<__range_key_type<_Range>>,
1586                     _Allocator>;
1587
1588#  endif
1589
1590template <class _Key, class _Tp, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value>>
1591unordered_map(initializer_list<pair<_Key, _Tp>>, typename allocator_traits<_Allocator>::size_type, _Allocator)
1592    -> unordered_map<remove_const_t<_Key>, _Tp, hash<remove_const_t<_Key>>, equal_to<remove_const_t<_Key>>, _Allocator>;
1593
1594template <class _Key, class _Tp, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value>>
1595unordered_map(initializer_list<pair<_Key, _Tp>>, _Allocator)
1596    -> unordered_map<remove_const_t<_Key>, _Tp, hash<remove_const_t<_Key>>, equal_to<remove_const_t<_Key>>, _Allocator>;
1597
1598template <class _Key,
1599          class _Tp,
1600          class _Hash,
1601          class _Allocator,
1602          class = enable_if_t<!__is_allocator<_Hash>::value>,
1603          class = enable_if_t<!is_integral<_Hash>::value>,
1604          class = enable_if_t<__is_allocator<_Allocator>::value>>
1605unordered_map(initializer_list<pair<_Key, _Tp>>, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
1606    -> unordered_map<remove_const_t<_Key>, _Tp, _Hash, equal_to<remove_const_t<_Key>>, _Allocator>;
1607#endif
1608
1609template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1610unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(size_type __n, const hasher& __hf, const key_equal& __eql)
1611    : __table_(__hf, __eql) {
1612  __table_.__rehash_unique(__n);
1613}
1614
1615template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1616unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
1617    size_type __n, const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
1618    : __table_(__hf, __eql, typename __table::allocator_type(__a)) {
1619  __table_.__rehash_unique(__n);
1620}
1621
1622template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1623inline unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(const allocator_type& __a)
1624    : __table_(typename __table::allocator_type(__a)) {}
1625
1626template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1627template <class _InputIterator>
1628unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(_InputIterator __first, _InputIterator __last) {
1629  insert(__first, __last);
1630}
1631
1632template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1633template <class _InputIterator>
1634unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
1635    _InputIterator __first, _InputIterator __last, size_type __n, const hasher& __hf, const key_equal& __eql)
1636    : __table_(__hf, __eql) {
1637  __table_.__rehash_unique(__n);
1638  insert(__first, __last);
1639}
1640
1641template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1642template <class _InputIterator>
1643unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
1644    _InputIterator __first,
1645    _InputIterator __last,
1646    size_type __n,
1647    const hasher& __hf,
1648    const key_equal& __eql,
1649    const allocator_type& __a)
1650    : __table_(__hf, __eql, typename __table::allocator_type(__a)) {
1651  __table_.__rehash_unique(__n);
1652  insert(__first, __last);
1653}
1654
1655template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1656unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(const unordered_map& __u) : __table_(__u.__table_) {
1657  __table_.__rehash_unique(__u.bucket_count());
1658  insert(__u.begin(), __u.end());
1659}
1660
1661template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1662unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(const unordered_map& __u, const allocator_type& __a)
1663    : __table_(__u.__table_, typename __table::allocator_type(__a)) {
1664  __table_.__rehash_unique(__u.bucket_count());
1665  insert(__u.begin(), __u.end());
1666}
1667
1668#ifndef _LIBCPP_CXX03_LANG
1669
1670template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1671inline unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(unordered_map&& __u)
1672    _NOEXCEPT_(is_nothrow_move_constructible<__table>::value)
1673    : __table_(std::move(__u.__table_)) {}
1674
1675template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1676unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(unordered_map&& __u, const allocator_type& __a)
1677    : __table_(std::move(__u.__table_), typename __table::allocator_type(__a)) {
1678  if (__a != __u.get_allocator()) {
1679    iterator __i = __u.begin();
1680    while (__u.size() != 0) {
1681      __table_.__emplace_unique(__u.__table_.remove((__i++).__i_)->__get_value().__move());
1682    }
1683  }
1684}
1685
1686template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1687unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(initializer_list<value_type> __il) {
1688  insert(__il.begin(), __il.end());
1689}
1690
1691template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1692unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
1693    initializer_list<value_type> __il, size_type __n, const hasher& __hf, const key_equal& __eql)
1694    : __table_(__hf, __eql) {
1695  __table_.__rehash_unique(__n);
1696  insert(__il.begin(), __il.end());
1697}
1698
1699template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1700unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
1701    initializer_list<value_type> __il,
1702    size_type __n,
1703    const hasher& __hf,
1704    const key_equal& __eql,
1705    const allocator_type& __a)
1706    : __table_(__hf, __eql, typename __table::allocator_type(__a)) {
1707  __table_.__rehash_unique(__n);
1708  insert(__il.begin(), __il.end());
1709}
1710
1711template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1712inline unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>&
1713unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(unordered_map&& __u)
1714    _NOEXCEPT_(is_nothrow_move_assignable<__table>::value) {
1715  __table_ = std::move(__u.__table_);
1716  return *this;
1717}
1718
1719template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1720inline unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>&
1721unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(initializer_list<value_type> __il) {
1722  __table_.__assign_unique(__il.begin(), __il.end());
1723  return *this;
1724}
1725
1726#endif // _LIBCPP_CXX03_LANG
1727
1728template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1729template <class _InputIterator>
1730inline void unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::insert(_InputIterator __first, _InputIterator __last) {
1731  for (; __first != __last; ++__first)
1732    __table_.__insert_unique(*__first);
1733}
1734
1735#ifndef _LIBCPP_CXX03_LANG
1736
1737template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1738_Tp& unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator[](const key_type& __k) {
1739  return __table_
1740      .__emplace_unique_key_args(__k, piecewise_construct, std::forward_as_tuple(__k), std::forward_as_tuple())
1741      .first->__get_value()
1742      .second;
1743}
1744
1745template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1746_Tp& unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator[](key_type&& __k) {
1747  return __table_
1748      .__emplace_unique_key_args(
1749          __k, piecewise_construct, std::forward_as_tuple(std::move(__k)), std::forward_as_tuple())
1750      .first->__get_value()
1751      .second;
1752}
1753#else // _LIBCPP_CXX03_LANG
1754
1755template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1756typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder
1757unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node_with_key(const key_type& __k) {
1758  __node_allocator& __na = __table_.__node_alloc();
1759  __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
1760  __node_traits::construct(__na, std::addressof(__h->__get_value().__get_value().first), __k);
1761  __h.get_deleter().__first_constructed = true;
1762  __node_traits::construct(__na, std::addressof(__h->__get_value().__get_value().second));
1763  __h.get_deleter().__second_constructed = true;
1764  return __h;
1765}
1766
1767template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1768_Tp& unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator[](const key_type& __k) {
1769  iterator __i = find(__k);
1770  if (__i != end())
1771    return __i->second;
1772  __node_holder __h        = __construct_node_with_key(__k);
1773  pair<iterator, bool> __r = __table_.__node_insert_unique(__h.get());
1774  __h.release();
1775  return __r.first->second;
1776}
1777
1778#endif // _LIBCPP_CXX03_LANG
1779
1780template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1781_Tp& unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::at(const key_type& __k) {
1782  iterator __i = find(__k);
1783  if (__i == end())
1784    __throw_out_of_range("unordered_map::at: key not found");
1785  return __i->second;
1786}
1787
1788template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1789const _Tp& unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::at(const key_type& __k) const {
1790  const_iterator __i = find(__k);
1791  if (__i == end())
1792    __throw_out_of_range("unordered_map::at: key not found");
1793  return __i->second;
1794}
1795
1796template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1797inline _LIBCPP_HIDE_FROM_ABI void
1798swap(unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x, unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
1799    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) {
1800  __x.swap(__y);
1801}
1802
1803#if _LIBCPP_STD_VER >= 20
1804template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc, class _Predicate>
1805inline _LIBCPP_HIDE_FROM_ABI typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::size_type
1806erase_if(unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __c, _Predicate __pred) {
1807  return std::__libcpp_erase_if_container(__c, __pred);
1808}
1809#endif
1810
1811template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1812_LIBCPP_HIDE_FROM_ABI bool operator==(const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
1813                                      const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) {
1814  if (__x.size() != __y.size())
1815    return false;
1816  typedef typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::const_iterator const_iterator;
1817  for (const_iterator __i = __x.begin(), __ex = __x.end(), __ey = __y.end(); __i != __ex; ++__i) {
1818    const_iterator __j = __y.find(__i->first);
1819    if (__j == __ey || !(*__i == *__j))
1820      return false;
1821  }
1822  return true;
1823}
1824
1825#if _LIBCPP_STD_VER <= 17
1826
1827template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
1828inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
1829                                             const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) {
1830  return !(__x == __y);
1831}
1832
1833#endif
1834
1835template <class _Key,
1836          class _Tp,
1837          class _Hash  = hash<_Key>,
1838          class _Pred  = equal_to<_Key>,
1839          class _Alloc = allocator<pair<const _Key, _Tp> > >
1840class _LIBCPP_TEMPLATE_VIS unordered_multimap {
1841public:
1842  // types
1843  typedef _Key key_type;
1844  typedef _Tp mapped_type;
1845  typedef __type_identity_t<_Hash> hasher;
1846  typedef __type_identity_t<_Pred> key_equal;
1847  typedef __type_identity_t<_Alloc> allocator_type;
1848  typedef pair<const key_type, mapped_type> value_type;
1849  typedef value_type& reference;
1850  typedef const value_type& const_reference;
1851  static_assert((is_same<value_type, typename allocator_type::value_type>::value),
1852                "Allocator::value_type must be same type as value_type");
1853
1854private:
1855  typedef __hash_value_type<key_type, mapped_type> __value_type;
1856  typedef __unordered_map_hasher<key_type, __value_type, hasher, key_equal> __hasher;
1857  typedef __unordered_map_equal<key_type, __value_type, key_equal, hasher> __key_equal;
1858  typedef __rebind_alloc<allocator_traits<allocator_type>, __value_type> __allocator_type;
1859
1860  typedef __hash_table<__value_type, __hasher, __key_equal, __allocator_type> __table;
1861
1862  __table __table_;
1863
1864  typedef typename __table::_NodeTypes _NodeTypes;
1865  typedef typename __table::__node_traits __node_traits;
1866  typedef typename __table::__node_allocator __node_allocator;
1867  typedef typename __table::__node __node;
1868  typedef __hash_map_node_destructor<__node_allocator> _Dp;
1869  typedef unique_ptr<__node, _Dp> __node_holder;
1870  typedef allocator_traits<allocator_type> __alloc_traits;
1871  static_assert((is_same<typename __node_traits::size_type, typename __alloc_traits::size_type>::value),
1872                "Allocator uses different size_type for different types");
1873
1874  static_assert(is_same<allocator_type, __rebind_alloc<__alloc_traits, value_type> >::value,
1875                "[allocator.requirements] states that rebinding an allocator to the same type should result in the "
1876                "original allocator");
1877
1878public:
1879  typedef typename __alloc_traits::pointer pointer;
1880  typedef typename __alloc_traits::const_pointer const_pointer;
1881  typedef typename __table::size_type size_type;
1882  typedef typename __table::difference_type difference_type;
1883
1884  typedef __hash_map_iterator<typename __table::iterator> iterator;
1885  typedef __hash_map_const_iterator<typename __table::const_iterator> const_iterator;
1886  typedef __hash_map_iterator<typename __table::local_iterator> local_iterator;
1887  typedef __hash_map_const_iterator<typename __table::const_local_iterator> const_local_iterator;
1888
1889#if _LIBCPP_STD_VER >= 17
1890  typedef __map_node_handle<__node, allocator_type> node_type;
1891#endif
1892
1893  template <class _Key2, class _Tp2, class _Hash2, class _Pred2, class _Alloc2>
1894  friend class _LIBCPP_TEMPLATE_VIS unordered_map;
1895  template <class _Key2, class _Tp2, class _Hash2, class _Pred2, class _Alloc2>
1896  friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
1897
1898  _LIBCPP_HIDE_FROM_ABI unordered_multimap() _NOEXCEPT_(is_nothrow_default_constructible<__table>::value) {}
1899  explicit _LIBCPP_HIDE_FROM_ABI
1900  unordered_multimap(size_type __n, const hasher& __hf = hasher(), const key_equal& __eql = key_equal());
1901  _LIBCPP_HIDE_FROM_ABI
1902  unordered_multimap(size_type __n, const hasher& __hf, const key_equal& __eql, const allocator_type& __a);
1903  template <class _InputIterator>
1904  _LIBCPP_HIDE_FROM_ABI unordered_multimap(_InputIterator __first, _InputIterator __last);
1905  template <class _InputIterator>
1906  _LIBCPP_HIDE_FROM_ABI unordered_multimap(
1907      _InputIterator __first,
1908      _InputIterator __last,
1909      size_type __n,
1910      const hasher& __hf     = hasher(),
1911      const key_equal& __eql = key_equal());
1912  template <class _InputIterator>
1913  _LIBCPP_HIDE_FROM_ABI unordered_multimap(
1914      _InputIterator __first,
1915      _InputIterator __last,
1916      size_type __n,
1917      const hasher& __hf,
1918      const key_equal& __eql,
1919      const allocator_type& __a);
1920
1921#if _LIBCPP_STD_VER >= 23
1922  template <_ContainerCompatibleRange<value_type> _Range>
1923  _LIBCPP_HIDE_FROM_ABI unordered_multimap(
1924      from_range_t,
1925      _Range&& __range,
1926      size_type __n             = /*implementation-defined*/ 0,
1927      const hasher& __hf        = hasher(),
1928      const key_equal& __eql    = key_equal(),
1929      const allocator_type& __a = allocator_type())
1930      : __table_(__hf, __eql, typename __table::allocator_type(__a)) {
1931    if (__n > 0) {
1932      __table_.__rehash_multi(__n);
1933    }
1934    insert_range(std::forward<_Range>(__range));
1935  }
1936#endif
1937
1938  _LIBCPP_HIDE_FROM_ABI explicit unordered_multimap(const allocator_type& __a);
1939  _LIBCPP_HIDE_FROM_ABI unordered_multimap(const unordered_multimap& __u);
1940  _LIBCPP_HIDE_FROM_ABI unordered_multimap(const unordered_multimap& __u, const allocator_type& __a);
1941#ifndef _LIBCPP_CXX03_LANG
1942  _LIBCPP_HIDE_FROM_ABI unordered_multimap(unordered_multimap&& __u)
1943      _NOEXCEPT_(is_nothrow_move_constructible<__table>::value);
1944  _LIBCPP_HIDE_FROM_ABI unordered_multimap(unordered_multimap&& __u, const allocator_type& __a);
1945  _LIBCPP_HIDE_FROM_ABI unordered_multimap(initializer_list<value_type> __il);
1946  _LIBCPP_HIDE_FROM_ABI unordered_multimap(
1947      initializer_list<value_type> __il,
1948      size_type __n,
1949      const hasher& __hf     = hasher(),
1950      const key_equal& __eql = key_equal());
1951  _LIBCPP_HIDE_FROM_ABI unordered_multimap(
1952      initializer_list<value_type> __il,
1953      size_type __n,
1954      const hasher& __hf,
1955      const key_equal& __eql,
1956      const allocator_type& __a);
1957#endif // _LIBCPP_CXX03_LANG
1958#if _LIBCPP_STD_VER >= 14
1959  _LIBCPP_HIDE_FROM_ABI unordered_multimap(size_type __n, const allocator_type& __a)
1960      : unordered_multimap(__n, hasher(), key_equal(), __a) {}
1961  _LIBCPP_HIDE_FROM_ABI unordered_multimap(size_type __n, const hasher& __hf, const allocator_type& __a)
1962      : unordered_multimap(__n, __hf, key_equal(), __a) {}
1963  template <class _InputIterator>
1964  _LIBCPP_HIDE_FROM_ABI
1965  unordered_multimap(_InputIterator __first, _InputIterator __last, size_type __n, const allocator_type& __a)
1966      : unordered_multimap(__first, __last, __n, hasher(), key_equal(), __a) {}
1967  template <class _InputIterator>
1968  _LIBCPP_HIDE_FROM_ABI unordered_multimap(
1969      _InputIterator __first, _InputIterator __last, size_type __n, const hasher& __hf, const allocator_type& __a)
1970      : unordered_multimap(__first, __last, __n, __hf, key_equal(), __a) {}
1971
1972#  if _LIBCPP_STD_VER >= 23
1973  template <_ContainerCompatibleRange<value_type> _Range>
1974  _LIBCPP_HIDE_FROM_ABI unordered_multimap(from_range_t, _Range&& __range, size_type __n, const allocator_type& __a)
1975      : unordered_multimap(from_range, std::forward<_Range>(__range), __n, hasher(), key_equal(), __a) {}
1976
1977  template <_ContainerCompatibleRange<value_type> _Range>
1978  _LIBCPP_HIDE_FROM_ABI
1979  unordered_multimap(from_range_t, _Range&& __range, size_type __n, const hasher& __hf, const allocator_type& __a)
1980      : unordered_multimap(from_range, std::forward<_Range>(__range), __n, __hf, key_equal(), __a) {}
1981#  endif
1982
1983  _LIBCPP_HIDE_FROM_ABI unordered_multimap(initializer_list<value_type> __il, size_type __n, const allocator_type& __a)
1984      : unordered_multimap(__il, __n, hasher(), key_equal(), __a) {}
1985  _LIBCPP_HIDE_FROM_ABI
1986  unordered_multimap(initializer_list<value_type> __il, size_type __n, const hasher& __hf, const allocator_type& __a)
1987      : unordered_multimap(__il, __n, __hf, key_equal(), __a) {}
1988#endif
1989  _LIBCPP_HIDE_FROM_ABI ~unordered_multimap() {
1990    static_assert(sizeof(std::__diagnose_unordered_container_requirements<_Key, _Hash, _Pred>(0)), "");
1991  }
1992
1993  _LIBCPP_HIDE_FROM_ABI unordered_multimap& operator=(const unordered_multimap& __u) {
1994#ifndef _LIBCPP_CXX03_LANG
1995    __table_ = __u.__table_;
1996#else
1997    if (this != std::addressof(__u)) {
1998      __table_.clear();
1999      __table_.hash_function()   = __u.__table_.hash_function();
2000      __table_.key_eq()          = __u.__table_.key_eq();
2001      __table_.max_load_factor() = __u.__table_.max_load_factor();
2002      __table_.__copy_assign_alloc(__u.__table_);
2003      insert(__u.begin(), __u.end());
2004    }
2005#endif
2006    return *this;
2007  }
2008#ifndef _LIBCPP_CXX03_LANG
2009  _LIBCPP_HIDE_FROM_ABI unordered_multimap& operator=(unordered_multimap&& __u)
2010      _NOEXCEPT_(is_nothrow_move_assignable<__table>::value);
2011  _LIBCPP_HIDE_FROM_ABI unordered_multimap& operator=(initializer_list<value_type> __il);
2012#endif // _LIBCPP_CXX03_LANG
2013
2014  _LIBCPP_HIDE_FROM_ABI allocator_type get_allocator() const _NOEXCEPT {
2015    return allocator_type(__table_.__node_alloc());
2016  }
2017
2018  _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI bool empty() const _NOEXCEPT { return __table_.size() == 0; }
2019  _LIBCPP_HIDE_FROM_ABI size_type size() const _NOEXCEPT { return __table_.size(); }
2020  _LIBCPP_HIDE_FROM_ABI size_type max_size() const _NOEXCEPT { return __table_.max_size(); }
2021
2022  _LIBCPP_HIDE_FROM_ABI iterator begin() _NOEXCEPT { return __table_.begin(); }
2023  _LIBCPP_HIDE_FROM_ABI iterator end() _NOEXCEPT { return __table_.end(); }
2024  _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT { return __table_.begin(); }
2025  _LIBCPP_HIDE_FROM_ABI const_iterator end() const _NOEXCEPT { return __table_.end(); }
2026  _LIBCPP_HIDE_FROM_ABI const_iterator cbegin() const _NOEXCEPT { return __table_.begin(); }
2027  _LIBCPP_HIDE_FROM_ABI const_iterator cend() const _NOEXCEPT { return __table_.end(); }
2028
2029  _LIBCPP_HIDE_FROM_ABI iterator insert(const value_type& __x) { return __table_.__insert_multi(__x); }
2030
2031  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, const value_type& __x) {
2032    return __table_.__insert_multi(__p.__i_, __x);
2033  }
2034
2035  template <class _InputIterator>
2036  _LIBCPP_HIDE_FROM_ABI void insert(_InputIterator __first, _InputIterator __last);
2037
2038#if _LIBCPP_STD_VER >= 23
2039  template <_ContainerCompatibleRange<value_type> _Range>
2040  _LIBCPP_HIDE_FROM_ABI void insert_range(_Range&& __range) {
2041    for (auto&& __element : __range) {
2042      __table_.__insert_multi(std::forward<decltype(__element)>(__element));
2043    }
2044  }
2045#endif
2046
2047#ifndef _LIBCPP_CXX03_LANG
2048  _LIBCPP_HIDE_FROM_ABI void insert(initializer_list<value_type> __il) { insert(__il.begin(), __il.end()); }
2049  _LIBCPP_HIDE_FROM_ABI iterator insert(value_type&& __x) { return __table_.__insert_multi(std::move(__x)); }
2050
2051  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, value_type&& __x) {
2052    return __table_.__insert_multi(__p.__i_, std::move(__x));
2053  }
2054
2055  template <class _Pp, class = __enable_if_t<is_constructible<value_type, _Pp>::value> >
2056  _LIBCPP_HIDE_FROM_ABI iterator insert(_Pp&& __x) {
2057    return __table_.__insert_multi(std::forward<_Pp>(__x));
2058  }
2059
2060  template <class _Pp, class = __enable_if_t<is_constructible<value_type, _Pp>::value> >
2061  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, _Pp&& __x) {
2062    return __table_.__insert_multi(__p.__i_, std::forward<_Pp>(__x));
2063  }
2064
2065  template <class... _Args>
2066  _LIBCPP_HIDE_FROM_ABI iterator emplace(_Args&&... __args) {
2067    return __table_.__emplace_multi(std::forward<_Args>(__args)...);
2068  }
2069
2070  template <class... _Args>
2071  _LIBCPP_HIDE_FROM_ABI iterator emplace_hint(const_iterator __p, _Args&&... __args) {
2072    return __table_.__emplace_hint_multi(__p.__i_, std::forward<_Args>(__args)...);
2073  }
2074#endif // _LIBCPP_CXX03_LANG
2075
2076  _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __p) { return __table_.erase(__p.__i_); }
2077  _LIBCPP_HIDE_FROM_ABI iterator erase(iterator __p) { return __table_.erase(__p.__i_); }
2078  _LIBCPP_HIDE_FROM_ABI size_type erase(const key_type& __k) { return __table_.__erase_multi(__k); }
2079  _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __first, const_iterator __last) {
2080    return __table_.erase(__first.__i_, __last.__i_);
2081  }
2082  _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT { __table_.clear(); }
2083
2084#if _LIBCPP_STD_VER >= 17
2085  _LIBCPP_HIDE_FROM_ABI iterator insert(node_type&& __nh) {
2086    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(__nh.empty() || __nh.get_allocator() == get_allocator(),
2087                                        "node_type with incompatible allocator passed to unordered_multimap::insert()");
2088    return __table_.template __node_handle_insert_multi<node_type>(std::move(__nh));
2089  }
2090  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __hint, node_type&& __nh) {
2091    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(__nh.empty() || __nh.get_allocator() == get_allocator(),
2092                                        "node_type with incompatible allocator passed to unordered_multimap::insert()");
2093    return __table_.template __node_handle_insert_multi<node_type>(__hint.__i_, std::move(__nh));
2094  }
2095  _LIBCPP_HIDE_FROM_ABI node_type extract(key_type const& __key) {
2096    return __table_.template __node_handle_extract<node_type>(__key);
2097  }
2098  _LIBCPP_HIDE_FROM_ABI node_type extract(const_iterator __it) {
2099    return __table_.template __node_handle_extract<node_type>(__it.__i_);
2100  }
2101
2102  template <class _H2, class _P2>
2103  _LIBCPP_HIDE_FROM_ABI void merge(unordered_multimap<key_type, mapped_type, _H2, _P2, allocator_type>& __source) {
2104    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
2105        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
2106    return __table_.__node_handle_merge_multi(__source.__table_);
2107  }
2108  template <class _H2, class _P2>
2109  _LIBCPP_HIDE_FROM_ABI void merge(unordered_multimap<key_type, mapped_type, _H2, _P2, allocator_type>&& __source) {
2110    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
2111        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
2112    return __table_.__node_handle_merge_multi(__source.__table_);
2113  }
2114  template <class _H2, class _P2>
2115  _LIBCPP_HIDE_FROM_ABI void merge(unordered_map<key_type, mapped_type, _H2, _P2, allocator_type>& __source) {
2116    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
2117        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
2118    return __table_.__node_handle_merge_multi(__source.__table_);
2119  }
2120  template <class _H2, class _P2>
2121  _LIBCPP_HIDE_FROM_ABI void merge(unordered_map<key_type, mapped_type, _H2, _P2, allocator_type>&& __source) {
2122    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(
2123        __source.get_allocator() == get_allocator(), "merging container with incompatible allocator");
2124    return __table_.__node_handle_merge_multi(__source.__table_);
2125  }
2126#endif
2127
2128  _LIBCPP_HIDE_FROM_ABI void swap(unordered_multimap& __u) _NOEXCEPT_(__is_nothrow_swappable<__table>::value) {
2129    __table_.swap(__u.__table_);
2130  }
2131
2132  _LIBCPP_HIDE_FROM_ABI hasher hash_function() const { return __table_.hash_function().hash_function(); }
2133  _LIBCPP_HIDE_FROM_ABI key_equal key_eq() const { return __table_.key_eq().key_eq(); }
2134
2135  _LIBCPP_HIDE_FROM_ABI iterator find(const key_type& __k) { return __table_.find(__k); }
2136  _LIBCPP_HIDE_FROM_ABI const_iterator find(const key_type& __k) const { return __table_.find(__k); }
2137#if _LIBCPP_STD_VER >= 20
2138  template <class _K2,
2139            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
2140  _LIBCPP_HIDE_FROM_ABI iterator find(const _K2& __k) {
2141    return __table_.find(__k);
2142  }
2143  template <class _K2,
2144            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
2145  _LIBCPP_HIDE_FROM_ABI const_iterator find(const _K2& __k) const {
2146    return __table_.find(__k);
2147  }
2148#endif // _LIBCPP_STD_VER >= 20
2149
2150  _LIBCPP_HIDE_FROM_ABI size_type count(const key_type& __k) const { return __table_.__count_multi(__k); }
2151#if _LIBCPP_STD_VER >= 20
2152  template <class _K2,
2153            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
2154  _LIBCPP_HIDE_FROM_ABI size_type count(const _K2& __k) const {
2155    return __table_.__count_multi(__k);
2156  }
2157#endif // _LIBCPP_STD_VER >= 20
2158
2159#if _LIBCPP_STD_VER >= 20
2160  _LIBCPP_HIDE_FROM_ABI bool contains(const key_type& __k) const { return find(__k) != end(); }
2161
2162  template <class _K2,
2163            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
2164  _LIBCPP_HIDE_FROM_ABI bool contains(const _K2& __k) const {
2165    return find(__k) != end();
2166  }
2167#endif // _LIBCPP_STD_VER >= 20
2168
2169  _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> equal_range(const key_type& __k) {
2170    return __table_.__equal_range_multi(__k);
2171  }
2172  _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator> equal_range(const key_type& __k) const {
2173    return __table_.__equal_range_multi(__k);
2174  }
2175#if _LIBCPP_STD_VER >= 20
2176  template <class _K2,
2177            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
2178  _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator> equal_range(const _K2& __k) {
2179    return __table_.__equal_range_multi(__k);
2180  }
2181  template <class _K2,
2182            enable_if_t<__is_transparent<hasher, _K2>::value && __is_transparent<key_equal, _K2>::value>* = nullptr>
2183  _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator> equal_range(const _K2& __k) const {
2184    return __table_.__equal_range_multi(__k);
2185  }
2186#endif // _LIBCPP_STD_VER >= 20
2187
2188  _LIBCPP_HIDE_FROM_ABI size_type bucket_count() const _NOEXCEPT { return __table_.bucket_count(); }
2189  _LIBCPP_HIDE_FROM_ABI size_type max_bucket_count() const _NOEXCEPT { return __table_.max_bucket_count(); }
2190
2191  _LIBCPP_HIDE_FROM_ABI size_type bucket_size(size_type __n) const { return __table_.bucket_size(__n); }
2192  _LIBCPP_HIDE_FROM_ABI size_type bucket(const key_type& __k) const { return __table_.bucket(__k); }
2193
2194  _LIBCPP_HIDE_FROM_ABI local_iterator begin(size_type __n) { return __table_.begin(__n); }
2195  _LIBCPP_HIDE_FROM_ABI local_iterator end(size_type __n) { return __table_.end(__n); }
2196  _LIBCPP_HIDE_FROM_ABI const_local_iterator begin(size_type __n) const { return __table_.cbegin(__n); }
2197  _LIBCPP_HIDE_FROM_ABI const_local_iterator end(size_type __n) const { return __table_.cend(__n); }
2198  _LIBCPP_HIDE_FROM_ABI const_local_iterator cbegin(size_type __n) const { return __table_.cbegin(__n); }
2199  _LIBCPP_HIDE_FROM_ABI const_local_iterator cend(size_type __n) const { return __table_.cend(__n); }
2200
2201  _LIBCPP_HIDE_FROM_ABI float load_factor() const _NOEXCEPT { return __table_.load_factor(); }
2202  _LIBCPP_HIDE_FROM_ABI float max_load_factor() const _NOEXCEPT { return __table_.max_load_factor(); }
2203  _LIBCPP_HIDE_FROM_ABI void max_load_factor(float __mlf) { __table_.max_load_factor(__mlf); }
2204  _LIBCPP_HIDE_FROM_ABI void rehash(size_type __n) { __table_.__rehash_multi(__n); }
2205  _LIBCPP_HIDE_FROM_ABI void reserve(size_type __n) { __table_.__reserve_multi(__n); }
2206};
2207
2208#if _LIBCPP_STD_VER >= 17
2209template <class _InputIterator,
2210          class _Hash      = hash<__iter_key_type<_InputIterator>>,
2211          class _Pred      = equal_to<__iter_key_type<_InputIterator>>,
2212          class _Allocator = allocator<__iter_to_alloc_type<_InputIterator>>,
2213          class            = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
2214          class            = enable_if_t<!__is_allocator<_Hash>::value>,
2215          class            = enable_if_t<!is_integral<_Hash>::value>,
2216          class            = enable_if_t<!__is_allocator<_Pred>::value>,
2217          class            = enable_if_t<__is_allocator<_Allocator>::value>>
2218unordered_multimap(_InputIterator,
2219                   _InputIterator,
2220                   typename allocator_traits<_Allocator>::size_type = 0,
2221                   _Hash                                            = _Hash(),
2222                   _Pred                                            = _Pred(),
2223                   _Allocator                                       = _Allocator())
2224    -> unordered_multimap<__iter_key_type<_InputIterator>,
2225                          __iter_mapped_type<_InputIterator>,
2226                          _Hash,
2227                          _Pred,
2228                          _Allocator>;
2229
2230#  if _LIBCPP_STD_VER >= 23
2231template <ranges::input_range _Range,
2232          class _Hash      = hash<__range_key_type<_Range>>,
2233          class _Pred      = equal_to<__range_key_type<_Range>>,
2234          class _Allocator = allocator<__range_to_alloc_type<_Range>>,
2235          class            = enable_if_t<!__is_allocator<_Hash>::value>,
2236          class            = enable_if_t<!is_integral<_Hash>::value>,
2237          class            = enable_if_t<!__is_allocator<_Pred>::value>,
2238          class            = enable_if_t<__is_allocator<_Allocator>::value>>
2239unordered_multimap(from_range_t,
2240                   _Range&&,
2241                   typename allocator_traits<_Allocator>::size_type = 0,
2242                   _Hash                                            = _Hash(),
2243                   _Pred                                            = _Pred(),
2244                   _Allocator                                       = _Allocator())
2245    -> unordered_multimap<__range_key_type<_Range>, __range_mapped_type<_Range>, _Hash, _Pred, _Allocator>;
2246#  endif
2247
2248template <class _Key,
2249          class _Tp,
2250          class _Hash      = hash<remove_const_t<_Key>>,
2251          class _Pred      = equal_to<remove_const_t<_Key>>,
2252          class _Allocator = allocator<pair<const _Key, _Tp>>,
2253          class            = enable_if_t<!__is_allocator<_Hash>::value>,
2254          class            = enable_if_t<!is_integral<_Hash>::value>,
2255          class            = enable_if_t<!__is_allocator<_Pred>::value>,
2256          class            = enable_if_t<__is_allocator<_Allocator>::value>>
2257unordered_multimap(initializer_list<pair<_Key, _Tp>>,
2258                   typename allocator_traits<_Allocator>::size_type = 0,
2259                   _Hash                                            = _Hash(),
2260                   _Pred                                            = _Pred(),
2261                   _Allocator                                       = _Allocator())
2262    -> unordered_multimap<remove_const_t<_Key>, _Tp, _Hash, _Pred, _Allocator>;
2263
2264template <class _InputIterator,
2265          class _Allocator,
2266          class = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
2267          class = enable_if_t<__is_allocator<_Allocator>::value>>
2268unordered_multimap(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type, _Allocator)
2269    -> unordered_multimap<__iter_key_type<_InputIterator>,
2270                          __iter_mapped_type<_InputIterator>,
2271                          hash<__iter_key_type<_InputIterator>>,
2272                          equal_to<__iter_key_type<_InputIterator>>,
2273                          _Allocator>;
2274
2275template <class _InputIterator,
2276          class _Allocator,
2277          class = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
2278          class = enable_if_t<__is_allocator<_Allocator>::value>>
2279unordered_multimap(_InputIterator, _InputIterator, _Allocator)
2280    -> unordered_multimap<__iter_key_type<_InputIterator>,
2281                          __iter_mapped_type<_InputIterator>,
2282                          hash<__iter_key_type<_InputIterator>>,
2283                          equal_to<__iter_key_type<_InputIterator>>,
2284                          _Allocator>;
2285
2286template <class _InputIterator,
2287          class _Hash,
2288          class _Allocator,
2289          class = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
2290          class = enable_if_t<!__is_allocator<_Hash>::value>,
2291          class = enable_if_t<!is_integral<_Hash>::value>,
2292          class = enable_if_t<__is_allocator<_Allocator>::value>>
2293unordered_multimap(_InputIterator, _InputIterator, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
2294    -> unordered_multimap<__iter_key_type<_InputIterator>,
2295                          __iter_mapped_type<_InputIterator>,
2296                          _Hash,
2297                          equal_to<__iter_key_type<_InputIterator>>,
2298                          _Allocator>;
2299
2300#  if _LIBCPP_STD_VER >= 23
2301
2302template <ranges::input_range _Range, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value>>
2303unordered_multimap(from_range_t, _Range&&, typename allocator_traits<_Allocator>::size_type, _Allocator)
2304    -> unordered_multimap<__range_key_type<_Range>,
2305                          __range_mapped_type<_Range>,
2306                          hash<__range_key_type<_Range>>,
2307                          equal_to<__range_key_type<_Range>>,
2308                          _Allocator>;
2309
2310template <ranges::input_range _Range, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value>>
2311unordered_multimap(from_range_t, _Range&&, _Allocator)
2312    -> unordered_multimap<__range_key_type<_Range>,
2313                          __range_mapped_type<_Range>,
2314                          hash<__range_key_type<_Range>>,
2315                          equal_to<__range_key_type<_Range>>,
2316                          _Allocator>;
2317
2318template <ranges::input_range _Range,
2319          class _Hash,
2320          class _Allocator,
2321          class = enable_if_t<!__is_allocator<_Hash>::value>,
2322          class = enable_if_t<!is_integral<_Hash>::value>,
2323          class = enable_if_t<__is_allocator<_Allocator>::value>>
2324unordered_multimap(from_range_t, _Range&&, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
2325    -> unordered_multimap<__range_key_type<_Range>,
2326                          __range_mapped_type<_Range>,
2327                          _Hash,
2328                          equal_to<__range_key_type<_Range>>,
2329                          _Allocator>;
2330
2331#  endif
2332
2333template <class _Key, class _Tp, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value>>
2334unordered_multimap(initializer_list<pair<_Key, _Tp>>, typename allocator_traits<_Allocator>::size_type, _Allocator)
2335    -> unordered_multimap<remove_const_t<_Key>,
2336                          _Tp,
2337                          hash<remove_const_t<_Key>>,
2338                          equal_to<remove_const_t<_Key>>,
2339                          _Allocator>;
2340
2341template <class _Key, class _Tp, class _Allocator, class = enable_if_t<__is_allocator<_Allocator>::value>>
2342unordered_multimap(initializer_list<pair<_Key, _Tp>>, _Allocator)
2343    -> unordered_multimap<remove_const_t<_Key>,
2344                          _Tp,
2345                          hash<remove_const_t<_Key>>,
2346                          equal_to<remove_const_t<_Key>>,
2347                          _Allocator>;
2348
2349template <class _Key,
2350          class _Tp,
2351          class _Hash,
2352          class _Allocator,
2353          class = enable_if_t<!__is_allocator<_Hash>::value>,
2354          class = enable_if_t<!is_integral<_Hash>::value>,
2355          class = enable_if_t<__is_allocator<_Allocator>::value>>
2356unordered_multimap(
2357    initializer_list<pair<_Key, _Tp>>, typename allocator_traits<_Allocator>::size_type, _Hash, _Allocator)
2358    -> unordered_multimap<remove_const_t<_Key>, _Tp, _Hash, equal_to<remove_const_t<_Key>>, _Allocator>;
2359#endif
2360
2361template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2362unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
2363    size_type __n, const hasher& __hf, const key_equal& __eql)
2364    : __table_(__hf, __eql) {
2365  __table_.__rehash_multi(__n);
2366}
2367
2368template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2369unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
2370    size_type __n, const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
2371    : __table_(__hf, __eql, typename __table::allocator_type(__a)) {
2372  __table_.__rehash_multi(__n);
2373}
2374
2375template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2376template <class _InputIterator>
2377unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(_InputIterator __first, _InputIterator __last) {
2378  insert(__first, __last);
2379}
2380
2381template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2382template <class _InputIterator>
2383unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
2384    _InputIterator __first, _InputIterator __last, size_type __n, const hasher& __hf, const key_equal& __eql)
2385    : __table_(__hf, __eql) {
2386  __table_.__rehash_multi(__n);
2387  insert(__first, __last);
2388}
2389
2390template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2391template <class _InputIterator>
2392unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
2393    _InputIterator __first,
2394    _InputIterator __last,
2395    size_type __n,
2396    const hasher& __hf,
2397    const key_equal& __eql,
2398    const allocator_type& __a)
2399    : __table_(__hf, __eql, typename __table::allocator_type(__a)) {
2400  __table_.__rehash_multi(__n);
2401  insert(__first, __last);
2402}
2403
2404template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2405inline unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(const allocator_type& __a)
2406    : __table_(typename __table::allocator_type(__a)) {}
2407
2408template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2409unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(const unordered_multimap& __u)
2410    : __table_(__u.__table_) {
2411  __table_.__rehash_multi(__u.bucket_count());
2412  insert(__u.begin(), __u.end());
2413}
2414
2415template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2416unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
2417    const unordered_multimap& __u, const allocator_type& __a)
2418    : __table_(__u.__table_, typename __table::allocator_type(__a)) {
2419  __table_.__rehash_multi(__u.bucket_count());
2420  insert(__u.begin(), __u.end());
2421}
2422
2423#ifndef _LIBCPP_CXX03_LANG
2424
2425template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2426inline unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(unordered_multimap&& __u)
2427    _NOEXCEPT_(is_nothrow_move_constructible<__table>::value)
2428    : __table_(std::move(__u.__table_)) {}
2429
2430template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2431unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
2432    unordered_multimap&& __u, const allocator_type& __a)
2433    : __table_(std::move(__u.__table_), typename __table::allocator_type(__a)) {
2434  if (__a != __u.get_allocator()) {
2435    iterator __i = __u.begin();
2436    while (__u.size() != 0) {
2437      __table_.__insert_multi(__u.__table_.remove((__i++).__i_)->__get_value().__move());
2438    }
2439  }
2440}
2441
2442template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2443unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(initializer_list<value_type> __il) {
2444  insert(__il.begin(), __il.end());
2445}
2446
2447template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2448unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
2449    initializer_list<value_type> __il, size_type __n, const hasher& __hf, const key_equal& __eql)
2450    : __table_(__hf, __eql) {
2451  __table_.__rehash_multi(__n);
2452  insert(__il.begin(), __il.end());
2453}
2454
2455template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2456unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
2457    initializer_list<value_type> __il,
2458    size_type __n,
2459    const hasher& __hf,
2460    const key_equal& __eql,
2461    const allocator_type& __a)
2462    : __table_(__hf, __eql, typename __table::allocator_type(__a)) {
2463  __table_.__rehash_multi(__n);
2464  insert(__il.begin(), __il.end());
2465}
2466
2467template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2468inline unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>&
2469unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(unordered_multimap&& __u)
2470    _NOEXCEPT_(is_nothrow_move_assignable<__table>::value) {
2471  __table_ = std::move(__u.__table_);
2472  return *this;
2473}
2474
2475template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2476inline unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>&
2477unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(initializer_list<value_type> __il) {
2478  __table_.__assign_multi(__il.begin(), __il.end());
2479  return *this;
2480}
2481
2482#endif // _LIBCPP_CXX03_LANG
2483
2484template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2485template <class _InputIterator>
2486inline void unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::insert(_InputIterator __first, _InputIterator __last) {
2487  for (; __first != __last; ++__first)
2488    __table_.__insert_multi(*__first);
2489}
2490
2491template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2492inline _LIBCPP_HIDE_FROM_ABI void
2493swap(unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x, unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
2494    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) {
2495  __x.swap(__y);
2496}
2497
2498#if _LIBCPP_STD_VER >= 20
2499template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc, class _Predicate>
2500inline _LIBCPP_HIDE_FROM_ABI typename unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::size_type
2501erase_if(unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __c, _Predicate __pred) {
2502  return std::__libcpp_erase_if_container(__c, __pred);
2503}
2504#endif
2505
2506template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2507_LIBCPP_HIDE_FROM_ABI bool operator==(const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
2508                                      const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) {
2509  if (__x.size() != __y.size())
2510    return false;
2511  typedef typename unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::const_iterator const_iterator;
2512  typedef pair<const_iterator, const_iterator> _EqRng;
2513  for (const_iterator __i = __x.begin(), __ex = __x.end(); __i != __ex;) {
2514    _EqRng __xeq = __x.equal_range(__i->first);
2515    _EqRng __yeq = __y.equal_range(__i->first);
2516    if (std::distance(__xeq.first, __xeq.second) != std::distance(__yeq.first, __yeq.second) ||
2517        !std::is_permutation(__xeq.first, __xeq.second, __yeq.first))
2518      return false;
2519    __i = __xeq.second;
2520  }
2521  return true;
2522}
2523
2524#if _LIBCPP_STD_VER <= 17
2525
2526template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
2527inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
2528                                             const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) {
2529  return !(__x == __y);
2530}
2531
2532#endif
2533
2534_LIBCPP_END_NAMESPACE_STD
2535
2536#if _LIBCPP_STD_VER >= 17
2537_LIBCPP_BEGIN_NAMESPACE_STD
2538namespace pmr {
2539template <class _KeyT, class _ValueT, class _HashT = std::hash<_KeyT>, class _PredT = std::equal_to<_KeyT>>
2540using unordered_map _LIBCPP_AVAILABILITY_PMR =
2541    std::unordered_map<_KeyT, _ValueT, _HashT, _PredT, polymorphic_allocator<std::pair<const _KeyT, _ValueT>>>;
2542
2543template <class _KeyT, class _ValueT, class _HashT = std::hash<_KeyT>, class _PredT = std::equal_to<_KeyT>>
2544using unordered_multimap _LIBCPP_AVAILABILITY_PMR =
2545    std::unordered_multimap<_KeyT, _ValueT, _HashT, _PredT, polymorphic_allocator<std::pair<const _KeyT, _ValueT>>>;
2546} // namespace pmr
2547_LIBCPP_END_NAMESPACE_STD
2548#endif
2549
2550_LIBCPP_POP_MACROS
2551
2552#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
2553#  include <algorithm>
2554#  include <bit>
2555#  include <concepts>
2556#  include <cstdlib>
2557#  include <iterator>
2558#  include <type_traits>
2559#endif
2560
2561#endif // _LIBCPP_UNORDERED_MAP
2562