xref: /freebsd/contrib/llvm-project/libcxx/include/__hash_table (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
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___HASH_TABLE
11#define _LIBCPP___HASH_TABLE
12
13#include <__algorithm/max.h>
14#include <__algorithm/min.h>
15#include <__assert>
16#include <__bit/countl.h>
17#include <__config>
18#include <__functional/hash.h>
19#include <__functional/invoke.h>
20#include <__iterator/iterator_traits.h>
21#include <__memory/addressof.h>
22#include <__memory/allocator_traits.h>
23#include <__memory/compressed_pair.h>
24#include <__memory/pointer_traits.h>
25#include <__memory/swap_allocator.h>
26#include <__memory/unique_ptr.h>
27#include <__type_traits/can_extract_key.h>
28#include <__type_traits/conditional.h>
29#include <__type_traits/is_const.h>
30#include <__type_traits/is_copy_constructible.h>
31#include <__type_traits/is_nothrow_constructible.h>
32#include <__type_traits/is_nothrow_copy_constructible.h>
33#include <__type_traits/is_nothrow_default_constructible.h>
34#include <__type_traits/is_nothrow_move_assignable.h>
35#include <__type_traits/is_nothrow_move_constructible.h>
36#include <__type_traits/is_pointer.h>
37#include <__type_traits/is_reference.h>
38#include <__type_traits/is_swappable.h>
39#include <__type_traits/remove_const.h>
40#include <__type_traits/remove_cvref.h>
41#include <__utility/forward.h>
42#include <__utility/move.h>
43#include <__utility/pair.h>
44#include <__utility/swap.h>
45#include <cmath>
46#include <cstring>
47#include <initializer_list>
48
49#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
50#  pragma GCC system_header
51#endif
52
53_LIBCPP_PUSH_MACROS
54#include <__undef_macros>
55
56
57_LIBCPP_BEGIN_NAMESPACE_STD
58
59template <class _Key, class _Tp>
60struct __hash_value_type;
61
62template <class _Tp>
63struct __is_hash_value_type_imp : false_type {};
64
65template <class _Key, class _Value>
66struct __is_hash_value_type_imp<__hash_value_type<_Key, _Value> > : true_type {};
67
68template <class ..._Args>
69struct __is_hash_value_type : false_type {};
70
71template <class _One>
72struct __is_hash_value_type<_One> : __is_hash_value_type_imp<__remove_cvref_t<_One> > {};
73
74_LIBCPP_EXPORTED_FROM_ABI size_t __next_prime(size_t __n);
75
76template <class _NodePtr>
77struct __hash_node_base
78{
79    typedef typename pointer_traits<_NodePtr>::element_type __node_type;
80    typedef __hash_node_base __first_node;
81    typedef __rebind_pointer_t<_NodePtr, __first_node> __node_base_pointer;
82    typedef _NodePtr __node_pointer;
83
84#if defined(_LIBCPP_ABI_FIX_UNORDERED_NODE_POINTER_UB)
85  typedef __node_base_pointer __next_pointer;
86#else
87    typedef __conditional_t<is_pointer<__node_pointer>::value, __node_base_pointer, __node_pointer> __next_pointer;
88#endif
89
90    __next_pointer    __next_;
91
92    _LIBCPP_INLINE_VISIBILITY
93    __next_pointer __ptr() _NOEXCEPT {
94        return static_cast<__next_pointer>(
95            pointer_traits<__node_base_pointer>::pointer_to(*this));
96    }
97
98    _LIBCPP_INLINE_VISIBILITY
99    __node_pointer __upcast() _NOEXCEPT {
100        return static_cast<__node_pointer>(
101            pointer_traits<__node_base_pointer>::pointer_to(*this));
102    }
103
104    _LIBCPP_INLINE_VISIBILITY
105    size_t __hash() const _NOEXCEPT {
106        return static_cast<__node_type const&>(*this).__hash_;
107    }
108
109    _LIBCPP_INLINE_VISIBILITY __hash_node_base() _NOEXCEPT : __next_(nullptr) {}
110};
111
112template <class _Tp, class _VoidPtr>
113struct _LIBCPP_STANDALONE_DEBUG __hash_node
114    : public __hash_node_base
115             <
116                 __rebind_pointer_t<_VoidPtr, __hash_node<_Tp, _VoidPtr> >
117             >
118{
119    typedef _Tp __node_value_type;
120
121    size_t            __hash_;
122    __node_value_type __value_;
123};
124
125inline _LIBCPP_INLINE_VISIBILITY
126bool
127__is_hash_power2(size_t __bc)
128{
129    return __bc > 2 && !(__bc & (__bc - 1));
130}
131
132inline _LIBCPP_INLINE_VISIBILITY
133size_t
134__constrain_hash(size_t __h, size_t __bc)
135{
136    return !(__bc & (__bc - 1)) ? __h & (__bc - 1) :
137        (__h < __bc ? __h : __h % __bc);
138}
139
140inline _LIBCPP_INLINE_VISIBILITY
141size_t
142__next_hash_pow2(size_t __n)
143{
144    return __n < 2 ? __n : (size_t(1) << (numeric_limits<size_t>::digits - __libcpp_clz(__n-1)));
145}
146
147
148template <class _Tp, class _Hash, class _Equal, class _Alloc> class __hash_table;
149
150template <class _NodePtr>      class _LIBCPP_TEMPLATE_VIS __hash_iterator;
151template <class _ConstNodePtr> class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
152template <class _NodePtr>      class _LIBCPP_TEMPLATE_VIS __hash_local_iterator;
153template <class _ConstNodePtr> class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
154template <class _HashIterator> class _LIBCPP_TEMPLATE_VIS __hash_map_iterator;
155template <class _HashIterator> class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
156
157template <class _Tp>
158struct __hash_key_value_types {
159  static_assert(!is_reference<_Tp>::value && !is_const<_Tp>::value, "");
160  typedef _Tp key_type;
161  typedef _Tp __node_value_type;
162  typedef _Tp __container_value_type;
163  static const bool __is_map = false;
164
165  _LIBCPP_INLINE_VISIBILITY
166  static key_type const& __get_key(_Tp const& __v) {
167    return __v;
168  }
169  _LIBCPP_INLINE_VISIBILITY
170  static __container_value_type const& __get_value(__node_value_type const& __v) {
171    return __v;
172  }
173  _LIBCPP_INLINE_VISIBILITY
174  static __container_value_type* __get_ptr(__node_value_type& __n) {
175    return _VSTD::addressof(__n);
176  }
177  _LIBCPP_INLINE_VISIBILITY
178  static __container_value_type&& __move(__node_value_type& __v) {
179    return _VSTD::move(__v);
180  }
181};
182
183template <class _Key, class _Tp>
184struct __hash_key_value_types<__hash_value_type<_Key, _Tp> > {
185  typedef _Key                                         key_type;
186  typedef _Tp                                          mapped_type;
187  typedef __hash_value_type<_Key, _Tp>                 __node_value_type;
188  typedef pair<const _Key, _Tp>                        __container_value_type;
189  typedef __container_value_type                       __map_value_type;
190  static const bool __is_map = true;
191
192  _LIBCPP_INLINE_VISIBILITY
193  static key_type const& __get_key(__container_value_type const& __v) {
194    return __v.first;
195  }
196
197  template <class _Up>
198  _LIBCPP_INLINE_VISIBILITY
199  static __enable_if_t<__is_same_uncvref<_Up, __node_value_type>::value, __container_value_type const&>
200  __get_value(_Up& __t) {
201    return __t.__get_value();
202  }
203
204  template <class _Up>
205  _LIBCPP_INLINE_VISIBILITY
206  static __enable_if_t<__is_same_uncvref<_Up, __container_value_type>::value, __container_value_type const&>
207  __get_value(_Up& __t) {
208    return __t;
209  }
210
211  _LIBCPP_INLINE_VISIBILITY
212  static __container_value_type* __get_ptr(__node_value_type& __n) {
213    return _VSTD::addressof(__n.__get_value());
214  }
215  _LIBCPP_INLINE_VISIBILITY
216  static pair<key_type&&, mapped_type&&> __move(__node_value_type& __v) {
217    return __v.__move();
218  }
219};
220
221template <class _Tp, class _AllocPtr, class _KVTypes = __hash_key_value_types<_Tp>,
222          bool = _KVTypes::__is_map>
223struct __hash_map_pointer_types {};
224
225template <class _Tp, class _AllocPtr, class _KVTypes>
226struct __hash_map_pointer_types<_Tp, _AllocPtr, _KVTypes, true> {
227  typedef typename _KVTypes::__map_value_type   _Mv;
228  typedef __rebind_pointer_t<_AllocPtr, _Mv>
229                                                       __map_value_type_pointer;
230  typedef __rebind_pointer_t<_AllocPtr, const _Mv>
231                                                 __const_map_value_type_pointer;
232};
233
234template <class _NodePtr, class _NodeT = typename pointer_traits<_NodePtr>::element_type>
235struct __hash_node_types;
236
237template <class _NodePtr, class _Tp, class _VoidPtr>
238struct __hash_node_types<_NodePtr, __hash_node<_Tp, _VoidPtr> >
239    : public __hash_key_value_types<_Tp>, __hash_map_pointer_types<_Tp, _VoidPtr>
240
241{
242  typedef __hash_key_value_types<_Tp>           __base;
243
244public:
245  typedef ptrdiff_t difference_type;
246  typedef size_t size_type;
247
248  typedef __rebind_pointer_t<_NodePtr, void>       __void_pointer;
249
250  typedef typename pointer_traits<_NodePtr>::element_type       __node_type;
251  typedef _NodePtr                                              __node_pointer;
252
253  typedef __hash_node_base<__node_pointer>                      __node_base_type;
254  typedef __rebind_pointer_t<_NodePtr, __node_base_type>
255                                                             __node_base_pointer;
256
257  typedef typename __node_base_type::__next_pointer          __next_pointer;
258
259  typedef _Tp                                                 __node_value_type;
260  typedef __rebind_pointer_t<_VoidPtr, __node_value_type>
261                                                      __node_value_type_pointer;
262  typedef __rebind_pointer_t<_VoidPtr, const __node_value_type>
263                                                __const_node_value_type_pointer;
264
265private:
266    static_assert(!is_const<__node_type>::value,
267                "_NodePtr should never be a pointer to const");
268    static_assert((is_same<typename pointer_traits<_VoidPtr>::element_type, void>::value),
269                  "_VoidPtr does not point to unqualified void type");
270    static_assert((is_same<__rebind_pointer_t<_VoidPtr, __node_type>,
271                          _NodePtr>::value), "_VoidPtr does not rebind to _NodePtr.");
272};
273
274template <class _HashIterator>
275struct __hash_node_types_from_iterator;
276template <class _NodePtr>
277struct __hash_node_types_from_iterator<__hash_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
278template <class _NodePtr>
279struct __hash_node_types_from_iterator<__hash_const_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
280template <class _NodePtr>
281struct __hash_node_types_from_iterator<__hash_local_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
282template <class _NodePtr>
283struct __hash_node_types_from_iterator<__hash_const_local_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
284
285
286template <class _NodeValueTp, class _VoidPtr>
287struct __make_hash_node_types {
288  typedef __hash_node<_NodeValueTp, _VoidPtr> _NodeTp;
289  typedef __rebind_pointer_t<_VoidPtr, _NodeTp> _NodePtr;
290  typedef __hash_node_types<_NodePtr> type;
291};
292
293template <class _NodePtr>
294class _LIBCPP_TEMPLATE_VIS __hash_iterator
295{
296    typedef __hash_node_types<_NodePtr> _NodeTypes;
297    typedef _NodePtr                            __node_pointer;
298    typedef typename _NodeTypes::__next_pointer __next_pointer;
299
300    __next_pointer            __node_;
301
302public:
303    typedef forward_iterator_tag                           iterator_category;
304    typedef typename _NodeTypes::__node_value_type         value_type;
305    typedef typename _NodeTypes::difference_type           difference_type;
306    typedef value_type&                                    reference;
307    typedef typename _NodeTypes::__node_value_type_pointer pointer;
308
309    _LIBCPP_INLINE_VISIBILITY __hash_iterator() _NOEXCEPT : __node_(nullptr) {
310    }
311
312    _LIBCPP_INLINE_VISIBILITY
313    reference operator*() const {
314        return __node_->__upcast()->__value_;
315    }
316
317    _LIBCPP_INLINE_VISIBILITY
318    pointer operator->() const {
319        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
320    }
321
322    _LIBCPP_INLINE_VISIBILITY
323    __hash_iterator& operator++() {
324        __node_ = __node_->__next_;
325        return *this;
326    }
327
328    _LIBCPP_INLINE_VISIBILITY
329    __hash_iterator operator++(int)
330    {
331        __hash_iterator __t(*this);
332        ++(*this);
333        return __t;
334    }
335
336    friend _LIBCPP_INLINE_VISIBILITY
337    bool operator==(const __hash_iterator& __x, const __hash_iterator& __y)
338    {
339        return __x.__node_ == __y.__node_;
340    }
341    friend _LIBCPP_INLINE_VISIBILITY
342    bool operator!=(const __hash_iterator& __x, const __hash_iterator& __y)
343        {return !(__x == __y);}
344
345private:
346    _LIBCPP_INLINE_VISIBILITY
347    explicit __hash_iterator(__next_pointer __node) _NOEXCEPT
348        : __node_(__node)
349        {
350        }
351
352    template <class, class, class, class> friend class __hash_table;
353    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
354    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_iterator;
355    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
356    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
357};
358
359template <class _NodePtr>
360class _LIBCPP_TEMPLATE_VIS __hash_const_iterator
361{
362    static_assert(!is_const<typename pointer_traits<_NodePtr>::element_type>::value, "");
363    typedef __hash_node_types<_NodePtr> _NodeTypes;
364    typedef _NodePtr                            __node_pointer;
365    typedef typename _NodeTypes::__next_pointer __next_pointer;
366
367    __next_pointer __node_;
368
369public:
370    typedef __hash_iterator<_NodePtr> __non_const_iterator;
371
372    typedef forward_iterator_tag                                 iterator_category;
373    typedef typename _NodeTypes::__node_value_type               value_type;
374    typedef typename _NodeTypes::difference_type                 difference_type;
375    typedef const value_type&                                    reference;
376    typedef typename _NodeTypes::__const_node_value_type_pointer pointer;
377
378
379    _LIBCPP_INLINE_VISIBILITY __hash_const_iterator() _NOEXCEPT : __node_(nullptr) {
380    }
381
382    _LIBCPP_INLINE_VISIBILITY
383    __hash_const_iterator(const __non_const_iterator& __x) _NOEXCEPT
384        : __node_(__x.__node_)
385    {
386    }
387
388    _LIBCPP_INLINE_VISIBILITY
389    reference operator*() const {
390        return __node_->__upcast()->__value_;
391    }
392    _LIBCPP_INLINE_VISIBILITY
393    pointer operator->() const {
394        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
395    }
396
397    _LIBCPP_INLINE_VISIBILITY
398    __hash_const_iterator& operator++() {
399        __node_ = __node_->__next_;
400        return *this;
401    }
402
403    _LIBCPP_INLINE_VISIBILITY
404    __hash_const_iterator operator++(int)
405    {
406        __hash_const_iterator __t(*this);
407        ++(*this);
408        return __t;
409    }
410
411    friend _LIBCPP_INLINE_VISIBILITY
412    bool operator==(const __hash_const_iterator& __x, const __hash_const_iterator& __y)
413    {
414        return __x.__node_ == __y.__node_;
415    }
416    friend _LIBCPP_INLINE_VISIBILITY
417    bool operator!=(const __hash_const_iterator& __x, const __hash_const_iterator& __y)
418        {return !(__x == __y);}
419
420private:
421    _LIBCPP_INLINE_VISIBILITY
422    explicit __hash_const_iterator(__next_pointer __node) _NOEXCEPT
423        : __node_(__node)
424        {
425        }
426
427    template <class, class, class, class> friend class __hash_table;
428    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
429    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
430    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
431};
432
433template <class _NodePtr>
434class _LIBCPP_TEMPLATE_VIS __hash_local_iterator
435{
436    typedef __hash_node_types<_NodePtr> _NodeTypes;
437    typedef _NodePtr                            __node_pointer;
438    typedef typename _NodeTypes::__next_pointer __next_pointer;
439
440    __next_pointer         __node_;
441    size_t                 __bucket_;
442    size_t                 __bucket_count_;
443
444public:
445    typedef forward_iterator_tag                                iterator_category;
446    typedef typename _NodeTypes::__node_value_type              value_type;
447    typedef typename _NodeTypes::difference_type                difference_type;
448    typedef value_type&                                         reference;
449    typedef typename _NodeTypes::__node_value_type_pointer      pointer;
450
451    _LIBCPP_INLINE_VISIBILITY __hash_local_iterator() _NOEXCEPT : __node_(nullptr) {
452    }
453
454    _LIBCPP_INLINE_VISIBILITY
455    reference operator*() const {
456        return __node_->__upcast()->__value_;
457    }
458
459    _LIBCPP_INLINE_VISIBILITY
460    pointer operator->() const {
461        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
462    }
463
464    _LIBCPP_INLINE_VISIBILITY
465    __hash_local_iterator& operator++() {
466        __node_ = __node_->__next_;
467        if (__node_ != nullptr && std::__constrain_hash(__node_->__hash(), __bucket_count_) != __bucket_)
468            __node_ = nullptr;
469        return *this;
470    }
471
472    _LIBCPP_INLINE_VISIBILITY
473    __hash_local_iterator operator++(int)
474    {
475        __hash_local_iterator __t(*this);
476        ++(*this);
477        return __t;
478    }
479
480    friend _LIBCPP_INLINE_VISIBILITY
481    bool operator==(const __hash_local_iterator& __x, const __hash_local_iterator& __y)
482    {
483        return __x.__node_ == __y.__node_;
484    }
485    friend _LIBCPP_INLINE_VISIBILITY
486    bool operator!=(const __hash_local_iterator& __x, const __hash_local_iterator& __y)
487        {return !(__x == __y);}
488
489private:
490    _LIBCPP_INLINE_VISIBILITY
491    explicit __hash_local_iterator(__next_pointer __node, size_t __bucket,
492                                   size_t __bucket_count) _NOEXCEPT
493        : __node_(__node),
494          __bucket_(__bucket),
495          __bucket_count_(__bucket_count)
496        {
497            if (__node_ != nullptr)
498                __node_ = __node_->__next_;
499        }
500
501    template <class, class, class, class> friend class __hash_table;
502    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
503    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_iterator;
504};
505
506template <class _ConstNodePtr>
507class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator
508{
509    typedef __hash_node_types<_ConstNodePtr> _NodeTypes;
510    typedef _ConstNodePtr                       __node_pointer;
511    typedef typename _NodeTypes::__next_pointer __next_pointer;
512
513    __next_pointer         __node_;
514    size_t                 __bucket_;
515    size_t                 __bucket_count_;
516
517    typedef pointer_traits<__node_pointer>          __pointer_traits;
518    typedef typename __pointer_traits::element_type __node;
519    typedef __remove_const_t<__node>                  __non_const_node;
520    typedef __rebind_pointer_t<__node_pointer, __non_const_node>
521        __non_const_node_pointer;
522public:
523    typedef __hash_local_iterator<__non_const_node_pointer>
524                                                    __non_const_iterator;
525
526    typedef forward_iterator_tag                                 iterator_category;
527    typedef typename _NodeTypes::__node_value_type               value_type;
528    typedef typename _NodeTypes::difference_type                 difference_type;
529    typedef const value_type&                                    reference;
530    typedef typename _NodeTypes::__const_node_value_type_pointer pointer;
531
532
533    _LIBCPP_INLINE_VISIBILITY __hash_const_local_iterator() _NOEXCEPT : __node_(nullptr) {
534    }
535
536    _LIBCPP_INLINE_VISIBILITY
537    __hash_const_local_iterator(const __non_const_iterator& __x) _NOEXCEPT
538        : __node_(__x.__node_),
539          __bucket_(__x.__bucket_),
540          __bucket_count_(__x.__bucket_count_)
541    {
542    }
543
544    _LIBCPP_INLINE_VISIBILITY
545    reference operator*() const {
546        return __node_->__upcast()->__value_;
547    }
548
549    _LIBCPP_INLINE_VISIBILITY
550    pointer operator->() const {
551        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
552    }
553
554    _LIBCPP_INLINE_VISIBILITY
555    __hash_const_local_iterator& operator++() {
556        __node_ = __node_->__next_;
557        if (__node_ != nullptr && std::__constrain_hash(__node_->__hash(), __bucket_count_) != __bucket_)
558            __node_ = nullptr;
559        return *this;
560    }
561
562    _LIBCPP_INLINE_VISIBILITY
563    __hash_const_local_iterator operator++(int)
564    {
565        __hash_const_local_iterator __t(*this);
566        ++(*this);
567        return __t;
568    }
569
570    friend _LIBCPP_INLINE_VISIBILITY
571    bool operator==(const __hash_const_local_iterator& __x, const __hash_const_local_iterator& __y)
572    {
573        return __x.__node_ == __y.__node_;
574    }
575    friend _LIBCPP_INLINE_VISIBILITY
576    bool operator!=(const __hash_const_local_iterator& __x, const __hash_const_local_iterator& __y)
577        {return !(__x == __y);}
578
579private:
580    _LIBCPP_INLINE_VISIBILITY
581    explicit __hash_const_local_iterator(__next_pointer __node_ptr, size_t __bucket,
582                                         size_t __bucket_count) _NOEXCEPT
583        : __node_(__node_ptr),
584          __bucket_(__bucket),
585          __bucket_count_(__bucket_count)
586        {
587            if (__node_ != nullptr)
588                __node_ = __node_->__next_;
589        }
590
591    template <class, class, class, class> friend class __hash_table;
592    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
593};
594
595template <class _Alloc>
596class __bucket_list_deallocator
597{
598    typedef _Alloc                                          allocator_type;
599    typedef allocator_traits<allocator_type>                __alloc_traits;
600    typedef typename __alloc_traits::size_type              size_type;
601
602    __compressed_pair<size_type, allocator_type> __data_;
603public:
604    typedef typename __alloc_traits::pointer pointer;
605
606    _LIBCPP_INLINE_VISIBILITY
607    __bucket_list_deallocator()
608        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
609        : __data_(0, __default_init_tag()) {}
610
611    _LIBCPP_INLINE_VISIBILITY
612    __bucket_list_deallocator(const allocator_type& __a, size_type __size)
613        _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)
614        : __data_(__size, __a) {}
615
616    _LIBCPP_INLINE_VISIBILITY
617    __bucket_list_deallocator(__bucket_list_deallocator&& __x)
618        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
619        : __data_(_VSTD::move(__x.__data_))
620    {
621        __x.size() = 0;
622    }
623
624    _LIBCPP_INLINE_VISIBILITY
625    size_type& size() _NOEXCEPT {return __data_.first();}
626    _LIBCPP_INLINE_VISIBILITY
627    size_type  size() const _NOEXCEPT {return __data_.first();}
628
629    _LIBCPP_INLINE_VISIBILITY
630    allocator_type& __alloc() _NOEXCEPT {return __data_.second();}
631    _LIBCPP_INLINE_VISIBILITY
632    const allocator_type& __alloc() const _NOEXCEPT {return __data_.second();}
633
634    _LIBCPP_INLINE_VISIBILITY
635    void operator()(pointer __p) _NOEXCEPT
636    {
637        __alloc_traits::deallocate(__alloc(), __p, size());
638    }
639};
640
641template <class _Alloc> class __hash_map_node_destructor;
642
643template <class _Alloc>
644class __hash_node_destructor
645{
646    typedef _Alloc                                          allocator_type;
647    typedef allocator_traits<allocator_type>                __alloc_traits;
648
649public:
650    typedef typename __alloc_traits::pointer                pointer;
651private:
652    typedef __hash_node_types<pointer> _NodeTypes;
653
654    allocator_type& __na_;
655
656public:
657    bool __value_constructed;
658
659    _LIBCPP_HIDE_FROM_ABI __hash_node_destructor(__hash_node_destructor const&) = default;
660    _LIBCPP_HIDE_FROM_ABI __hash_node_destructor& operator=(const __hash_node_destructor&) = delete;
661
662
663    _LIBCPP_INLINE_VISIBILITY
664    explicit __hash_node_destructor(allocator_type& __na,
665                                    bool __constructed = false) _NOEXCEPT
666        : __na_(__na),
667          __value_constructed(__constructed)
668        {}
669
670    _LIBCPP_INLINE_VISIBILITY
671    void operator()(pointer __p) _NOEXCEPT
672    {
673        if (__value_constructed)
674            __alloc_traits::destroy(__na_, _NodeTypes::__get_ptr(__p->__value_));
675        if (__p)
676            __alloc_traits::deallocate(__na_, __p, 1);
677    }
678
679    template <class> friend class __hash_map_node_destructor;
680};
681
682#if _LIBCPP_STD_VER >= 17
683template <class _NodeType, class _Alloc>
684struct __generic_container_node_destructor;
685
686template <class _Tp, class _VoidPtr, class _Alloc>
687struct __generic_container_node_destructor<__hash_node<_Tp, _VoidPtr>, _Alloc>
688    : __hash_node_destructor<_Alloc>
689{
690    using __hash_node_destructor<_Alloc>::__hash_node_destructor;
691};
692#endif
693
694template <class _Key, class _Hash, class _Equal>
695struct __enforce_unordered_container_requirements {
696#ifndef _LIBCPP_CXX03_LANG
697    static_assert(__check_hash_requirements<_Key, _Hash>::value,
698    "the specified hash does not meet the Hash requirements");
699    static_assert(is_copy_constructible<_Equal>::value,
700    "the specified comparator is required to be copy constructible");
701#endif
702    typedef int type;
703};
704
705template <class _Key, class _Hash, class _Equal>
706#ifndef _LIBCPP_CXX03_LANG
707    _LIBCPP_DIAGNOSE_WARNING(!__invokable<_Equal const&, _Key const&, _Key const&>::value,
708    "the specified comparator type does not provide a viable const call operator")
709    _LIBCPP_DIAGNOSE_WARNING(!__invokable<_Hash const&, _Key const&>::value,
710    "the specified hash functor does not provide a viable const call operator")
711#endif
712typename __enforce_unordered_container_requirements<_Key, _Hash, _Equal>::type
713__diagnose_unordered_container_requirements(int);
714
715// This dummy overload is used so that the compiler won't emit a spurious
716// "no matching function for call to __diagnose_unordered_xxx" diagnostic
717// when the overload above causes a hard error.
718template <class _Key, class _Hash, class _Equal>
719int __diagnose_unordered_container_requirements(void*);
720
721template <class _Tp, class _Hash, class _Equal, class _Alloc>
722class __hash_table
723{
724public:
725    typedef _Tp    value_type;
726    typedef _Hash  hasher;
727    typedef _Equal key_equal;
728    typedef _Alloc allocator_type;
729
730private:
731    typedef allocator_traits<allocator_type> __alloc_traits;
732    typedef typename
733      __make_hash_node_types<value_type, typename __alloc_traits::void_pointer>::type
734                                                                     _NodeTypes;
735public:
736
737    typedef typename _NodeTypes::__node_value_type           __node_value_type;
738    typedef typename _NodeTypes::__container_value_type      __container_value_type;
739    typedef typename _NodeTypes::key_type                    key_type;
740    typedef value_type&                              reference;
741    typedef const value_type&                        const_reference;
742    typedef typename __alloc_traits::pointer         pointer;
743    typedef typename __alloc_traits::const_pointer   const_pointer;
744#ifndef _LIBCPP_ABI_FIX_UNORDERED_CONTAINER_SIZE_TYPE
745    typedef typename __alloc_traits::size_type       size_type;
746#else
747    typedef typename _NodeTypes::size_type           size_type;
748#endif
749    typedef typename _NodeTypes::difference_type     difference_type;
750public:
751    // Create __node
752
753    typedef typename _NodeTypes::__node_type __node;
754    typedef __rebind_alloc<__alloc_traits, __node>   __node_allocator;
755    typedef allocator_traits<__node_allocator>       __node_traits;
756    typedef typename _NodeTypes::__void_pointer      __void_pointer;
757    typedef typename _NodeTypes::__node_pointer      __node_pointer;
758    typedef typename _NodeTypes::__node_pointer      __node_const_pointer;
759    typedef typename _NodeTypes::__node_base_type    __first_node;
760    typedef typename _NodeTypes::__node_base_pointer __node_base_pointer;
761    typedef typename _NodeTypes::__next_pointer      __next_pointer;
762
763private:
764    // check for sane allocator pointer rebinding semantics. Rebinding the
765    // allocator for a new pointer type should be exactly the same as rebinding
766    // the pointer using 'pointer_traits'.
767    static_assert((is_same<__node_pointer, typename __node_traits::pointer>::value),
768                  "Allocator does not rebind pointers in a sane manner.");
769    typedef __rebind_alloc<__node_traits, __first_node> __node_base_allocator;
770    typedef allocator_traits<__node_base_allocator> __node_base_traits;
771    static_assert((is_same<__node_base_pointer, typename __node_base_traits::pointer>::value),
772                 "Allocator does not rebind pointers in a sane manner.");
773
774private:
775
776    typedef __rebind_alloc<__node_traits, __next_pointer>  __pointer_allocator;
777    typedef __bucket_list_deallocator<__pointer_allocator> __bucket_list_deleter;
778    typedef unique_ptr<__next_pointer[], __bucket_list_deleter> __bucket_list;
779    typedef allocator_traits<__pointer_allocator>          __pointer_alloc_traits;
780    typedef typename __bucket_list_deleter::pointer       __node_pointer_pointer;
781
782    // --- Member data begin ---
783    __bucket_list                                         __bucket_list_;
784    __compressed_pair<__first_node, __node_allocator>     __p1_;
785    __compressed_pair<size_type, hasher>                  __p2_;
786    __compressed_pair<float, key_equal>                   __p3_;
787    // --- Member data end ---
788
789    _LIBCPP_INLINE_VISIBILITY
790    size_type& size() _NOEXCEPT {return __p2_.first();}
791public:
792    _LIBCPP_INLINE_VISIBILITY
793    size_type  size() const _NOEXCEPT {return __p2_.first();}
794
795    _LIBCPP_INLINE_VISIBILITY
796    hasher& hash_function() _NOEXCEPT {return __p2_.second();}
797    _LIBCPP_INLINE_VISIBILITY
798    const hasher& hash_function() const _NOEXCEPT {return __p2_.second();}
799
800    _LIBCPP_INLINE_VISIBILITY
801    float& max_load_factor() _NOEXCEPT {return __p3_.first();}
802    _LIBCPP_INLINE_VISIBILITY
803    float  max_load_factor() const _NOEXCEPT {return __p3_.first();}
804
805    _LIBCPP_INLINE_VISIBILITY
806    key_equal& key_eq() _NOEXCEPT {return __p3_.second();}
807    _LIBCPP_INLINE_VISIBILITY
808    const key_equal& key_eq() const _NOEXCEPT {return __p3_.second();}
809
810    _LIBCPP_INLINE_VISIBILITY
811    __node_allocator& __node_alloc() _NOEXCEPT {return __p1_.second();}
812    _LIBCPP_INLINE_VISIBILITY
813    const __node_allocator& __node_alloc() const _NOEXCEPT
814        {return __p1_.second();}
815
816public:
817    typedef __hash_iterator<__node_pointer>                   iterator;
818    typedef __hash_const_iterator<__node_pointer>             const_iterator;
819    typedef __hash_local_iterator<__node_pointer>             local_iterator;
820    typedef __hash_const_local_iterator<__node_pointer>       const_local_iterator;
821
822    _LIBCPP_INLINE_VISIBILITY
823    __hash_table()
824        _NOEXCEPT_(
825            is_nothrow_default_constructible<__bucket_list>::value &&
826            is_nothrow_default_constructible<__first_node>::value &&
827            is_nothrow_default_constructible<__node_allocator>::value &&
828            is_nothrow_default_constructible<hasher>::value &&
829            is_nothrow_default_constructible<key_equal>::value);
830    _LIBCPP_INLINE_VISIBILITY
831    __hash_table(const hasher& __hf, const key_equal& __eql);
832    _LIBCPP_HIDE_FROM_ABI __hash_table(const hasher& __hf, const key_equal& __eql,
833                 const allocator_type& __a);
834    _LIBCPP_HIDE_FROM_ABI explicit __hash_table(const allocator_type& __a);
835    _LIBCPP_HIDE_FROM_ABI __hash_table(const __hash_table& __u);
836    _LIBCPP_HIDE_FROM_ABI __hash_table(const __hash_table& __u, const allocator_type& __a);
837    _LIBCPP_HIDE_FROM_ABI __hash_table(__hash_table&& __u)
838        _NOEXCEPT_(
839            is_nothrow_move_constructible<__bucket_list>::value &&
840            is_nothrow_move_constructible<__first_node>::value &&
841            is_nothrow_move_constructible<__node_allocator>::value &&
842            is_nothrow_move_constructible<hasher>::value &&
843            is_nothrow_move_constructible<key_equal>::value);
844    _LIBCPP_HIDE_FROM_ABI __hash_table(__hash_table&& __u, const allocator_type& __a);
845    _LIBCPP_HIDE_FROM_ABI ~__hash_table();
846
847    _LIBCPP_HIDE_FROM_ABI __hash_table& operator=(const __hash_table& __u);
848    _LIBCPP_INLINE_VISIBILITY
849    __hash_table& operator=(__hash_table&& __u)
850        _NOEXCEPT_(
851            __node_traits::propagate_on_container_move_assignment::value &&
852            is_nothrow_move_assignable<__node_allocator>::value &&
853            is_nothrow_move_assignable<hasher>::value &&
854            is_nothrow_move_assignable<key_equal>::value);
855    template <class _InputIterator>
856    _LIBCPP_HIDE_FROM_ABI void __assign_unique(_InputIterator __first, _InputIterator __last);
857    template <class _InputIterator>
858    _LIBCPP_HIDE_FROM_ABI void __assign_multi(_InputIterator __first, _InputIterator __last);
859
860    _LIBCPP_INLINE_VISIBILITY
861    size_type max_size() const _NOEXCEPT
862    {
863        return _VSTD::min<size_type>(
864            __node_traits::max_size(__node_alloc()),
865            numeric_limits<difference_type >::max()
866        );
867    }
868
869private:
870    _LIBCPP_INLINE_VISIBILITY
871    __next_pointer __node_insert_multi_prepare(size_t __cp_hash,
872                                               value_type& __cp_val);
873    _LIBCPP_INLINE_VISIBILITY
874    void __node_insert_multi_perform(__node_pointer __cp,
875                                     __next_pointer __pn) _NOEXCEPT;
876
877    _LIBCPP_INLINE_VISIBILITY
878    __next_pointer __node_insert_unique_prepare(size_t __nd_hash,
879                                                value_type& __nd_val);
880    _LIBCPP_INLINE_VISIBILITY
881    void __node_insert_unique_perform(__node_pointer __ptr) _NOEXCEPT;
882
883public:
884    _LIBCPP_INLINE_VISIBILITY
885    pair<iterator, bool> __node_insert_unique(__node_pointer __nd);
886    _LIBCPP_INLINE_VISIBILITY
887    iterator             __node_insert_multi(__node_pointer __nd);
888    _LIBCPP_INLINE_VISIBILITY
889    iterator             __node_insert_multi(const_iterator __p,
890                                             __node_pointer __nd);
891
892    template <class _Key, class ..._Args>
893    _LIBCPP_INLINE_VISIBILITY
894    pair<iterator, bool> __emplace_unique_key_args(_Key const& __k, _Args&&... __args);
895
896    template <class... _Args>
897    _LIBCPP_INLINE_VISIBILITY
898    pair<iterator, bool> __emplace_unique_impl(_Args&&... __args);
899
900    template <class _Pp>
901    _LIBCPP_INLINE_VISIBILITY
902    pair<iterator, bool> __emplace_unique(_Pp&& __x) {
903      return __emplace_unique_extract_key(_VSTD::forward<_Pp>(__x),
904                                          __can_extract_key<_Pp, key_type>());
905    }
906
907    template <class _First, class _Second>
908    _LIBCPP_INLINE_VISIBILITY
909    __enable_if_t<__can_extract_map_key<_First, key_type, __container_value_type>::value, pair<iterator, bool> >
910    __emplace_unique(_First&& __f, _Second&& __s) {
911        return __emplace_unique_key_args(__f, _VSTD::forward<_First>(__f),
912                                              _VSTD::forward<_Second>(__s));
913    }
914
915    template <class... _Args>
916    _LIBCPP_INLINE_VISIBILITY
917    pair<iterator, bool> __emplace_unique(_Args&&... __args) {
918      return __emplace_unique_impl(_VSTD::forward<_Args>(__args)...);
919    }
920
921    template <class _Pp>
922    _LIBCPP_INLINE_VISIBILITY
923    pair<iterator, bool>
924    __emplace_unique_extract_key(_Pp&& __x, __extract_key_fail_tag) {
925      return __emplace_unique_impl(_VSTD::forward<_Pp>(__x));
926    }
927    template <class _Pp>
928    _LIBCPP_INLINE_VISIBILITY
929    pair<iterator, bool>
930    __emplace_unique_extract_key(_Pp&& __x, __extract_key_self_tag) {
931      return __emplace_unique_key_args(__x, _VSTD::forward<_Pp>(__x));
932    }
933    template <class _Pp>
934    _LIBCPP_INLINE_VISIBILITY
935    pair<iterator, bool>
936    __emplace_unique_extract_key(_Pp&& __x, __extract_key_first_tag) {
937      return __emplace_unique_key_args(__x.first, _VSTD::forward<_Pp>(__x));
938    }
939
940    template <class... _Args>
941    _LIBCPP_INLINE_VISIBILITY
942    iterator __emplace_multi(_Args&&... __args);
943    template <class... _Args>
944    _LIBCPP_INLINE_VISIBILITY
945    iterator __emplace_hint_multi(const_iterator __p, _Args&&... __args);
946
947
948    _LIBCPP_INLINE_VISIBILITY
949    pair<iterator, bool>
950    __insert_unique(__container_value_type&& __x) {
951      return __emplace_unique_key_args(_NodeTypes::__get_key(__x), _VSTD::move(__x));
952    }
953
954    template <class _Pp, class = __enable_if_t<!__is_same_uncvref<_Pp, __container_value_type>::value> >
955    _LIBCPP_INLINE_VISIBILITY
956    pair<iterator, bool> __insert_unique(_Pp&& __x) {
957      return __emplace_unique(_VSTD::forward<_Pp>(__x));
958    }
959
960    template <class _Pp>
961    _LIBCPP_INLINE_VISIBILITY
962    iterator __insert_multi(_Pp&& __x) {
963      return __emplace_multi(_VSTD::forward<_Pp>(__x));
964    }
965
966    template <class _Pp>
967    _LIBCPP_INLINE_VISIBILITY
968    iterator __insert_multi(const_iterator __p, _Pp&& __x) {
969        return __emplace_hint_multi(__p, _VSTD::forward<_Pp>(__x));
970    }
971
972    _LIBCPP_INLINE_VISIBILITY
973    pair<iterator, bool> __insert_unique(const __container_value_type& __x) {
974        return __emplace_unique_key_args(_NodeTypes::__get_key(__x), __x);
975    }
976
977#if _LIBCPP_STD_VER >= 17
978    template <class _NodeHandle, class _InsertReturnType>
979    _LIBCPP_INLINE_VISIBILITY
980    _InsertReturnType __node_handle_insert_unique(_NodeHandle&& __nh);
981    template <class _NodeHandle>
982    _LIBCPP_INLINE_VISIBILITY
983    iterator __node_handle_insert_unique(const_iterator __hint,
984                                         _NodeHandle&& __nh);
985    template <class _Table>
986    _LIBCPP_INLINE_VISIBILITY
987    void __node_handle_merge_unique(_Table& __source);
988
989    template <class _NodeHandle>
990    _LIBCPP_INLINE_VISIBILITY
991    iterator __node_handle_insert_multi(_NodeHandle&& __nh);
992    template <class _NodeHandle>
993    _LIBCPP_INLINE_VISIBILITY
994    iterator __node_handle_insert_multi(const_iterator __hint, _NodeHandle&& __nh);
995    template <class _Table>
996    _LIBCPP_INLINE_VISIBILITY
997    void __node_handle_merge_multi(_Table& __source);
998
999    template <class _NodeHandle>
1000    _LIBCPP_INLINE_VISIBILITY
1001    _NodeHandle __node_handle_extract(key_type const& __key);
1002    template <class _NodeHandle>
1003    _LIBCPP_INLINE_VISIBILITY
1004    _NodeHandle __node_handle_extract(const_iterator __it);
1005#endif
1006
1007    _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT;
1008    _LIBCPP_INLINE_VISIBILITY void __rehash_unique(size_type __n) { __rehash<true>(__n); }
1009    _LIBCPP_INLINE_VISIBILITY void __rehash_multi(size_type __n) { __rehash<false>(__n); }
1010    _LIBCPP_INLINE_VISIBILITY void __reserve_unique(size_type __n)
1011    {
1012        __rehash_unique(static_cast<size_type>(std::ceil(__n / max_load_factor())));
1013    }
1014    _LIBCPP_INLINE_VISIBILITY void __reserve_multi(size_type __n)
1015    {
1016        __rehash_multi(static_cast<size_type>(std::ceil(__n / max_load_factor())));
1017    }
1018
1019    _LIBCPP_INLINE_VISIBILITY
1020    size_type bucket_count() const _NOEXCEPT
1021    {
1022        return __bucket_list_.get_deleter().size();
1023    }
1024
1025    _LIBCPP_INLINE_VISIBILITY
1026    iterator       begin() _NOEXCEPT;
1027    _LIBCPP_INLINE_VISIBILITY
1028    iterator       end() _NOEXCEPT;
1029    _LIBCPP_INLINE_VISIBILITY
1030    const_iterator begin() const _NOEXCEPT;
1031    _LIBCPP_INLINE_VISIBILITY
1032    const_iterator end() const _NOEXCEPT;
1033
1034    template <class _Key>
1035        _LIBCPP_INLINE_VISIBILITY
1036        size_type bucket(const _Key& __k) const
1037        {
1038            _LIBCPP_ASSERT_UNCATEGORIZED(bucket_count() > 0,
1039                "unordered container::bucket(key) called when bucket_count() == 0");
1040            return std::__constrain_hash(hash_function()(__k), bucket_count());
1041        }
1042
1043    template <class _Key>
1044    _LIBCPP_HIDE_FROM_ABI iterator       find(const _Key& __x);
1045    template <class _Key>
1046    _LIBCPP_HIDE_FROM_ABI const_iterator find(const _Key& __x) const;
1047
1048    typedef __hash_node_destructor<__node_allocator> _Dp;
1049    typedef unique_ptr<__node, _Dp> __node_holder;
1050
1051    _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __p);
1052    _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __first, const_iterator __last);
1053    template <class _Key>
1054    _LIBCPP_HIDE_FROM_ABI size_type __erase_unique(const _Key& __k);
1055    template <class _Key>
1056    _LIBCPP_HIDE_FROM_ABI size_type __erase_multi(const _Key& __k);
1057    _LIBCPP_HIDE_FROM_ABI __node_holder remove(const_iterator __p) _NOEXCEPT;
1058
1059    template <class _Key>
1060        _LIBCPP_INLINE_VISIBILITY
1061        size_type __count_unique(const _Key& __k) const;
1062    template <class _Key>
1063    _LIBCPP_HIDE_FROM_ABI size_type __count_multi(const _Key& __k) const;
1064
1065    template <class _Key>
1066    _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator>
1067        __equal_range_unique(const _Key& __k);
1068    template <class _Key>
1069    _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator>
1070        __equal_range_unique(const _Key& __k) const;
1071
1072    template <class _Key>
1073    _LIBCPP_HIDE_FROM_ABI pair<iterator, iterator>
1074        __equal_range_multi(const _Key& __k);
1075    template <class _Key>
1076    _LIBCPP_HIDE_FROM_ABI pair<const_iterator, const_iterator>
1077        __equal_range_multi(const _Key& __k) const;
1078
1079    _LIBCPP_HIDE_FROM_ABI void swap(__hash_table& __u)
1080#if _LIBCPP_STD_VER <= 11
1081        _NOEXCEPT_(
1082            __is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value
1083            && (!allocator_traits<__pointer_allocator>::propagate_on_container_swap::value
1084                  || __is_nothrow_swappable<__pointer_allocator>::value)
1085            && (!__node_traits::propagate_on_container_swap::value
1086                  || __is_nothrow_swappable<__node_allocator>::value)
1087            );
1088#else
1089     _NOEXCEPT_(__is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value);
1090#endif
1091
1092    _LIBCPP_INLINE_VISIBILITY
1093    size_type max_bucket_count() const _NOEXCEPT
1094        {return max_size(); }
1095    _LIBCPP_HIDE_FROM_ABI size_type bucket_size(size_type __n) const;
1096    _LIBCPP_INLINE_VISIBILITY float load_factor() const _NOEXCEPT
1097    {
1098        size_type __bc = bucket_count();
1099        return __bc != 0 ? (float)size() / __bc : 0.f;
1100    }
1101    _LIBCPP_INLINE_VISIBILITY void max_load_factor(float __mlf) _NOEXCEPT
1102    {
1103        _LIBCPP_ASSERT_UNCATEGORIZED(__mlf > 0,
1104            "unordered container::max_load_factor(lf) called with lf <= 0");
1105        max_load_factor() = _VSTD::max(__mlf, load_factor());
1106    }
1107
1108    _LIBCPP_INLINE_VISIBILITY
1109    local_iterator
1110    begin(size_type __n)
1111    {
1112        _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__n < bucket_count(),
1113            "unordered container::begin(n) called with n >= bucket_count()");
1114        return local_iterator(__bucket_list_[__n], __n, bucket_count());
1115    }
1116
1117    _LIBCPP_INLINE_VISIBILITY
1118    local_iterator
1119    end(size_type __n)
1120    {
1121        _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__n < bucket_count(),
1122            "unordered container::end(n) called with n >= bucket_count()");
1123        return local_iterator(nullptr, __n, bucket_count());
1124    }
1125
1126    _LIBCPP_INLINE_VISIBILITY
1127    const_local_iterator
1128    cbegin(size_type __n) const
1129    {
1130        _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__n < bucket_count(),
1131            "unordered container::cbegin(n) called with n >= bucket_count()");
1132        return const_local_iterator(__bucket_list_[__n], __n, bucket_count());
1133    }
1134
1135    _LIBCPP_INLINE_VISIBILITY
1136    const_local_iterator
1137    cend(size_type __n) const
1138    {
1139        _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__n < bucket_count(),
1140            "unordered container::cend(n) called with n >= bucket_count()");
1141        return const_local_iterator(nullptr, __n, bucket_count());
1142    }
1143
1144private:
1145    template <bool _UniqueKeys>
1146    _LIBCPP_HIDE_FROM_ABI void __rehash(size_type __n);
1147    template <bool _UniqueKeys>
1148    _LIBCPP_HIDE_FROM_ABI void __do_rehash(size_type __n);
1149
1150    template <class ..._Args>
1151    _LIBCPP_HIDE_FROM_ABI __node_holder __construct_node(_Args&& ...__args);
1152
1153    template <class _First, class ..._Rest>
1154    _LIBCPP_HIDE_FROM_ABI __node_holder __construct_node_hash(size_t __hash, _First&& __f, _Rest&&... __rest);
1155
1156
1157    _LIBCPP_INLINE_VISIBILITY
1158    void __copy_assign_alloc(const __hash_table& __u)
1159        {__copy_assign_alloc(__u, integral_constant<bool,
1160             __node_traits::propagate_on_container_copy_assignment::value>());}
1161    _LIBCPP_HIDE_FROM_ABI void __copy_assign_alloc(const __hash_table& __u, true_type);
1162    _LIBCPP_INLINE_VISIBILITY
1163        void __copy_assign_alloc(const __hash_table&, false_type) {}
1164
1165    _LIBCPP_HIDE_FROM_ABI void __move_assign(__hash_table& __u, false_type);
1166    _LIBCPP_HIDE_FROM_ABI void __move_assign(__hash_table& __u, true_type)
1167        _NOEXCEPT_(
1168            is_nothrow_move_assignable<__node_allocator>::value &&
1169            is_nothrow_move_assignable<hasher>::value &&
1170            is_nothrow_move_assignable<key_equal>::value);
1171    _LIBCPP_INLINE_VISIBILITY
1172    void __move_assign_alloc(__hash_table& __u)
1173        _NOEXCEPT_(
1174            !__node_traits::propagate_on_container_move_assignment::value ||
1175            (is_nothrow_move_assignable<__pointer_allocator>::value &&
1176             is_nothrow_move_assignable<__node_allocator>::value))
1177        {__move_assign_alloc(__u, integral_constant<bool,
1178             __node_traits::propagate_on_container_move_assignment::value>());}
1179    _LIBCPP_INLINE_VISIBILITY
1180    void __move_assign_alloc(__hash_table& __u, true_type)
1181        _NOEXCEPT_(
1182            is_nothrow_move_assignable<__pointer_allocator>::value &&
1183            is_nothrow_move_assignable<__node_allocator>::value)
1184    {
1185        __bucket_list_.get_deleter().__alloc() =
1186                _VSTD::move(__u.__bucket_list_.get_deleter().__alloc());
1187        __node_alloc() = _VSTD::move(__u.__node_alloc());
1188    }
1189    _LIBCPP_INLINE_VISIBILITY
1190        void __move_assign_alloc(__hash_table&, false_type) _NOEXCEPT {}
1191
1192    _LIBCPP_HIDE_FROM_ABI void __deallocate_node(__next_pointer __np) _NOEXCEPT;
1193    _LIBCPP_HIDE_FROM_ABI __next_pointer __detach() _NOEXCEPT;
1194
1195    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
1196    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
1197};
1198
1199template <class _Tp, class _Hash, class _Equal, class _Alloc>
1200inline
1201__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table()
1202    _NOEXCEPT_(
1203        is_nothrow_default_constructible<__bucket_list>::value &&
1204        is_nothrow_default_constructible<__first_node>::value &&
1205        is_nothrow_default_constructible<__node_allocator>::value &&
1206        is_nothrow_default_constructible<hasher>::value &&
1207        is_nothrow_default_constructible<key_equal>::value)
1208    : __p2_(0, __default_init_tag()),
1209      __p3_(1.0f, __default_init_tag())
1210{
1211}
1212
1213template <class _Tp, class _Hash, class _Equal, class _Alloc>
1214inline
1215__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const hasher& __hf,
1216                                                       const key_equal& __eql)
1217    : __bucket_list_(nullptr, __bucket_list_deleter()),
1218      __p1_(),
1219      __p2_(0, __hf),
1220      __p3_(1.0f, __eql)
1221{
1222}
1223
1224template <class _Tp, class _Hash, class _Equal, class _Alloc>
1225__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const hasher& __hf,
1226                                                       const key_equal& __eql,
1227                                                       const allocator_type& __a)
1228    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
1229      __p1_(__default_init_tag(), __node_allocator(__a)),
1230      __p2_(0, __hf),
1231      __p3_(1.0f, __eql)
1232{
1233}
1234
1235template <class _Tp, class _Hash, class _Equal, class _Alloc>
1236__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const allocator_type& __a)
1237    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
1238      __p1_(__default_init_tag(), __node_allocator(__a)),
1239      __p2_(0, __default_init_tag()),
1240      __p3_(1.0f, __default_init_tag())
1241{
1242}
1243
1244template <class _Tp, class _Hash, class _Equal, class _Alloc>
1245__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const __hash_table& __u)
1246    : __bucket_list_(nullptr,
1247          __bucket_list_deleter(allocator_traits<__pointer_allocator>::
1248              select_on_container_copy_construction(
1249                  __u.__bucket_list_.get_deleter().__alloc()), 0)),
1250      __p1_(__default_init_tag(), allocator_traits<__node_allocator>::
1251          select_on_container_copy_construction(__u.__node_alloc())),
1252      __p2_(0, __u.hash_function()),
1253      __p3_(__u.__p3_)
1254{
1255}
1256
1257template <class _Tp, class _Hash, class _Equal, class _Alloc>
1258__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const __hash_table& __u,
1259                                                       const allocator_type& __a)
1260    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
1261      __p1_(__default_init_tag(), __node_allocator(__a)),
1262      __p2_(0, __u.hash_function()),
1263      __p3_(__u.__p3_)
1264{
1265}
1266
1267template <class _Tp, class _Hash, class _Equal, class _Alloc>
1268__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(__hash_table&& __u)
1269        _NOEXCEPT_(
1270            is_nothrow_move_constructible<__bucket_list>::value &&
1271            is_nothrow_move_constructible<__first_node>::value &&
1272            is_nothrow_move_constructible<__node_allocator>::value &&
1273            is_nothrow_move_constructible<hasher>::value &&
1274            is_nothrow_move_constructible<key_equal>::value)
1275    : __bucket_list_(_VSTD::move(__u.__bucket_list_)),
1276      __p1_(_VSTD::move(__u.__p1_)),
1277      __p2_(_VSTD::move(__u.__p2_)),
1278      __p3_(_VSTD::move(__u.__p3_))
1279{
1280    if (size() > 0)
1281    {
1282        __bucket_list_[std::__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
1283            __p1_.first().__ptr();
1284        __u.__p1_.first().__next_ = nullptr;
1285        __u.size() = 0;
1286    }
1287}
1288
1289template <class _Tp, class _Hash, class _Equal, class _Alloc>
1290__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(__hash_table&& __u,
1291                                                       const allocator_type& __a)
1292    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
1293      __p1_(__default_init_tag(), __node_allocator(__a)),
1294      __p2_(0, _VSTD::move(__u.hash_function())),
1295      __p3_(_VSTD::move(__u.__p3_))
1296{
1297    if (__a == allocator_type(__u.__node_alloc()))
1298    {
1299        __bucket_list_.reset(__u.__bucket_list_.release());
1300        __bucket_list_.get_deleter().size() = __u.__bucket_list_.get_deleter().size();
1301        __u.__bucket_list_.get_deleter().size() = 0;
1302        if (__u.size() > 0)
1303        {
1304            __p1_.first().__next_ = __u.__p1_.first().__next_;
1305            __u.__p1_.first().__next_ = nullptr;
1306            __bucket_list_[std::__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
1307                __p1_.first().__ptr();
1308            size() = __u.size();
1309            __u.size() = 0;
1310        }
1311    }
1312}
1313
1314template <class _Tp, class _Hash, class _Equal, class _Alloc>
1315__hash_table<_Tp, _Hash, _Equal, _Alloc>::~__hash_table()
1316{
1317#if defined(_LIBCPP_CXX03_LANG)
1318    static_assert((is_copy_constructible<key_equal>::value),
1319                 "Predicate must be copy-constructible.");
1320    static_assert((is_copy_constructible<hasher>::value),
1321                 "Hasher must be copy-constructible.");
1322#endif
1323
1324    __deallocate_node(__p1_.first().__next_);
1325}
1326
1327template <class _Tp, class _Hash, class _Equal, class _Alloc>
1328void
1329__hash_table<_Tp, _Hash, _Equal, _Alloc>::__copy_assign_alloc(
1330        const __hash_table& __u, true_type)
1331{
1332    if (__node_alloc() != __u.__node_alloc())
1333    {
1334        clear();
1335        __bucket_list_.reset();
1336        __bucket_list_.get_deleter().size() = 0;
1337    }
1338    __bucket_list_.get_deleter().__alloc() = __u.__bucket_list_.get_deleter().__alloc();
1339    __node_alloc() = __u.__node_alloc();
1340}
1341
1342template <class _Tp, class _Hash, class _Equal, class _Alloc>
1343__hash_table<_Tp, _Hash, _Equal, _Alloc>&
1344__hash_table<_Tp, _Hash, _Equal, _Alloc>::operator=(const __hash_table& __u)
1345{
1346    if (this != _VSTD::addressof(__u))
1347    {
1348        __copy_assign_alloc(__u);
1349        hash_function() = __u.hash_function();
1350        key_eq() = __u.key_eq();
1351        max_load_factor() = __u.max_load_factor();
1352        __assign_multi(__u.begin(), __u.end());
1353    }
1354    return *this;
1355}
1356
1357template <class _Tp, class _Hash, class _Equal, class _Alloc>
1358void
1359__hash_table<_Tp, _Hash, _Equal, _Alloc>::__deallocate_node(__next_pointer __np)
1360    _NOEXCEPT
1361{
1362    __node_allocator& __na = __node_alloc();
1363    while (__np != nullptr)
1364    {
1365        __next_pointer __next = __np->__next_;
1366        __node_pointer __real_np = __np->__upcast();
1367        __node_traits::destroy(__na, _NodeTypes::__get_ptr(__real_np->__value_));
1368        __node_traits::deallocate(__na, __real_np, 1);
1369        __np = __next;
1370    }
1371}
1372
1373template <class _Tp, class _Hash, class _Equal, class _Alloc>
1374typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__next_pointer
1375__hash_table<_Tp, _Hash, _Equal, _Alloc>::__detach() _NOEXCEPT
1376{
1377    size_type __bc = bucket_count();
1378    for (size_type __i = 0; __i < __bc; ++__i)
1379        __bucket_list_[__i] = nullptr;
1380    size() = 0;
1381    __next_pointer __cache = __p1_.first().__next_;
1382    __p1_.first().__next_ = nullptr;
1383    return __cache;
1384}
1385
1386template <class _Tp, class _Hash, class _Equal, class _Alloc>
1387void
1388__hash_table<_Tp, _Hash, _Equal, _Alloc>::__move_assign(
1389        __hash_table& __u, true_type)
1390    _NOEXCEPT_(
1391        is_nothrow_move_assignable<__node_allocator>::value &&
1392        is_nothrow_move_assignable<hasher>::value &&
1393        is_nothrow_move_assignable<key_equal>::value)
1394{
1395    clear();
1396    __bucket_list_.reset(__u.__bucket_list_.release());
1397    __bucket_list_.get_deleter().size() = __u.__bucket_list_.get_deleter().size();
1398    __u.__bucket_list_.get_deleter().size() = 0;
1399    __move_assign_alloc(__u);
1400    size() = __u.size();
1401    hash_function() = _VSTD::move(__u.hash_function());
1402    max_load_factor() = __u.max_load_factor();
1403    key_eq() = _VSTD::move(__u.key_eq());
1404    __p1_.first().__next_ = __u.__p1_.first().__next_;
1405    if (size() > 0)
1406    {
1407        __bucket_list_[std::__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
1408            __p1_.first().__ptr();
1409        __u.__p1_.first().__next_ = nullptr;
1410        __u.size() = 0;
1411    }
1412}
1413
1414template <class _Tp, class _Hash, class _Equal, class _Alloc>
1415void
1416__hash_table<_Tp, _Hash, _Equal, _Alloc>::__move_assign(
1417        __hash_table& __u, false_type)
1418{
1419    if (__node_alloc() == __u.__node_alloc())
1420        __move_assign(__u, true_type());
1421    else
1422    {
1423        hash_function() = _VSTD::move(__u.hash_function());
1424        key_eq() = _VSTD::move(__u.key_eq());
1425        max_load_factor() = __u.max_load_factor();
1426        if (bucket_count() != 0)
1427        {
1428            __next_pointer __cache = __detach();
1429#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1430            try
1431            {
1432#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1433                const_iterator __i = __u.begin();
1434                while (__cache != nullptr && __u.size() != 0)
1435                {
1436                    __cache->__upcast()->__value_ =
1437                        _VSTD::move(__u.remove(__i++)->__value_);
1438                    __next_pointer __next = __cache->__next_;
1439                    __node_insert_multi(__cache->__upcast());
1440                    __cache = __next;
1441                }
1442#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1443            }
1444            catch (...)
1445            {
1446                __deallocate_node(__cache);
1447                throw;
1448            }
1449#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1450            __deallocate_node(__cache);
1451        }
1452        const_iterator __i = __u.begin();
1453        while (__u.size() != 0)
1454        {
1455            __node_holder __h = __construct_node(_NodeTypes::__move(__u.remove(__i++)->__value_));
1456            __node_insert_multi(__h.get());
1457            __h.release();
1458        }
1459    }
1460}
1461
1462template <class _Tp, class _Hash, class _Equal, class _Alloc>
1463inline
1464__hash_table<_Tp, _Hash, _Equal, _Alloc>&
1465__hash_table<_Tp, _Hash, _Equal, _Alloc>::operator=(__hash_table&& __u)
1466    _NOEXCEPT_(
1467        __node_traits::propagate_on_container_move_assignment::value &&
1468        is_nothrow_move_assignable<__node_allocator>::value &&
1469        is_nothrow_move_assignable<hasher>::value &&
1470        is_nothrow_move_assignable<key_equal>::value)
1471{
1472    __move_assign(__u, integral_constant<bool,
1473                  __node_traits::propagate_on_container_move_assignment::value>());
1474    return *this;
1475}
1476
1477template <class _Tp, class _Hash, class _Equal, class _Alloc>
1478template <class _InputIterator>
1479void
1480__hash_table<_Tp, _Hash, _Equal, _Alloc>::__assign_unique(_InputIterator __first,
1481                                                          _InputIterator __last)
1482{
1483    typedef iterator_traits<_InputIterator> _ITraits;
1484    typedef typename _ITraits::value_type _ItValueType;
1485    static_assert((is_same<_ItValueType, __container_value_type>::value),
1486                  "__assign_unique may only be called with the containers value type");
1487
1488    if (bucket_count() != 0)
1489    {
1490        __next_pointer __cache = __detach();
1491#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1492        try
1493        {
1494#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1495            for (; __cache != nullptr && __first != __last; ++__first)
1496            {
1497                __cache->__upcast()->__value_ = *__first;
1498                __next_pointer __next = __cache->__next_;
1499                __node_insert_unique(__cache->__upcast());
1500                __cache = __next;
1501            }
1502#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1503        }
1504        catch (...)
1505        {
1506            __deallocate_node(__cache);
1507            throw;
1508        }
1509#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1510        __deallocate_node(__cache);
1511    }
1512    for (; __first != __last; ++__first)
1513        __insert_unique(*__first);
1514}
1515
1516template <class _Tp, class _Hash, class _Equal, class _Alloc>
1517template <class _InputIterator>
1518void
1519__hash_table<_Tp, _Hash, _Equal, _Alloc>::__assign_multi(_InputIterator __first,
1520                                                         _InputIterator __last)
1521{
1522    typedef iterator_traits<_InputIterator> _ITraits;
1523    typedef typename _ITraits::value_type _ItValueType;
1524    static_assert((is_same<_ItValueType, __container_value_type>::value ||
1525                  is_same<_ItValueType, __node_value_type>::value),
1526                  "__assign_multi may only be called with the containers value type"
1527                  " or the nodes value type");
1528    if (bucket_count() != 0)
1529    {
1530        __next_pointer __cache = __detach();
1531#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1532        try
1533        {
1534#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1535            for (; __cache != nullptr && __first != __last; ++__first)
1536            {
1537                __cache->__upcast()->__value_ = *__first;
1538                __next_pointer __next = __cache->__next_;
1539                __node_insert_multi(__cache->__upcast());
1540                __cache = __next;
1541            }
1542#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
1543        }
1544        catch (...)
1545        {
1546            __deallocate_node(__cache);
1547            throw;
1548        }
1549#endif // _LIBCPP_HAS_NO_EXCEPTIONS
1550        __deallocate_node(__cache);
1551    }
1552    for (; __first != __last; ++__first)
1553        __insert_multi(_NodeTypes::__get_value(*__first));
1554}
1555
1556template <class _Tp, class _Hash, class _Equal, class _Alloc>
1557inline
1558typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
1559__hash_table<_Tp, _Hash, _Equal, _Alloc>::begin() _NOEXCEPT
1560{
1561    return iterator(__p1_.first().__next_);
1562}
1563
1564template <class _Tp, class _Hash, class _Equal, class _Alloc>
1565inline
1566typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
1567__hash_table<_Tp, _Hash, _Equal, _Alloc>::end() _NOEXCEPT
1568{
1569    return iterator(nullptr);
1570}
1571
1572template <class _Tp, class _Hash, class _Equal, class _Alloc>
1573inline
1574typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
1575__hash_table<_Tp, _Hash, _Equal, _Alloc>::begin() const _NOEXCEPT
1576{
1577    return const_iterator(__p1_.first().__next_);
1578}
1579
1580template <class _Tp, class _Hash, class _Equal, class _Alloc>
1581inline
1582typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
1583__hash_table<_Tp, _Hash, _Equal, _Alloc>::end() const _NOEXCEPT
1584{
1585    return const_iterator(nullptr);
1586}
1587
1588template <class _Tp, class _Hash, class _Equal, class _Alloc>
1589void
1590__hash_table<_Tp, _Hash, _Equal, _Alloc>::clear() _NOEXCEPT
1591{
1592    if (size() > 0)
1593    {
1594        __deallocate_node(__p1_.first().__next_);
1595        __p1_.first().__next_ = nullptr;
1596        size_type __bc = bucket_count();
1597        for (size_type __i = 0; __i < __bc; ++__i)
1598            __bucket_list_[__i] = nullptr;
1599        size() = 0;
1600    }
1601}
1602
1603
1604// Prepare the container for an insertion of the value __value with the hash
1605// __hash. This does a lookup into the container to see if __value is already
1606// present, and performs a rehash if necessary. Returns a pointer to the
1607// existing element if it exists, otherwise nullptr.
1608//
1609// Note that this function does forward exceptions if key_eq() throws, and never
1610// mutates __value or actually inserts into the map.
1611template <class _Tp, class _Hash, class _Equal, class _Alloc>
1612_LIBCPP_INLINE_VISIBILITY
1613typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__next_pointer
1614__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_unique_prepare(
1615    size_t __hash, value_type& __value)
1616{
1617    size_type __bc = bucket_count();
1618
1619    if (__bc != 0)
1620    {
1621        size_t __chash = std::__constrain_hash(__hash, __bc);
1622        __next_pointer __ndptr = __bucket_list_[__chash];
1623        if (__ndptr != nullptr)
1624        {
1625            for (__ndptr = __ndptr->__next_; __ndptr != nullptr &&
1626                    (__ndptr->__hash() == __hash ||
1627                     std::__constrain_hash(__ndptr->__hash(), __bc) == __chash);
1628                                                     __ndptr = __ndptr->__next_)
1629            {
1630                if ((__ndptr->__hash() == __hash) &&
1631                    key_eq()(__ndptr->__upcast()->__value_, __value))
1632                    return __ndptr;
1633            }
1634        }
1635    }
1636    if (size()+1 > __bc * max_load_factor() || __bc == 0)
1637    {
1638        __rehash_unique(_VSTD::max<size_type>(2 * __bc + !std::__is_hash_power2(__bc),
1639                                     size_type(std::ceil(float(size() + 1) / max_load_factor()))));
1640    }
1641    return nullptr;
1642}
1643
1644// Insert the node __nd into the container by pushing it into the right bucket,
1645// and updating size(). Assumes that __nd->__hash is up-to-date, and that
1646// rehashing has already occurred and that no element with the same key exists
1647// in the map.
1648template <class _Tp, class _Hash, class _Equal, class _Alloc>
1649_LIBCPP_INLINE_VISIBILITY
1650void
1651__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_unique_perform(
1652    __node_pointer __nd) _NOEXCEPT
1653{
1654    size_type __bc = bucket_count();
1655    size_t __chash = std::__constrain_hash(__nd->__hash(), __bc);
1656    // insert_after __bucket_list_[__chash], or __first_node if bucket is null
1657    __next_pointer __pn = __bucket_list_[__chash];
1658    if (__pn == nullptr)
1659    {
1660        __pn =__p1_.first().__ptr();
1661        __nd->__next_ = __pn->__next_;
1662        __pn->__next_ = __nd->__ptr();
1663        // fix up __bucket_list_
1664        __bucket_list_[__chash] = __pn;
1665        if (__nd->__next_ != nullptr)
1666            __bucket_list_[std::__constrain_hash(__nd->__next_->__hash(), __bc)] = __nd->__ptr();
1667    }
1668    else
1669    {
1670        __nd->__next_ = __pn->__next_;
1671        __pn->__next_ = __nd->__ptr();
1672    }
1673    ++size();
1674}
1675
1676template <class _Tp, class _Hash, class _Equal, class _Alloc>
1677pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
1678__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_unique(__node_pointer __nd)
1679{
1680    __nd->__hash_ = hash_function()(__nd->__value_);
1681    __next_pointer __existing_node =
1682        __node_insert_unique_prepare(__nd->__hash(), __nd->__value_);
1683
1684    // Insert the node, unless it already exists in the container.
1685    bool __inserted = false;
1686    if (__existing_node == nullptr)
1687    {
1688        __node_insert_unique_perform(__nd);
1689        __existing_node = __nd->__ptr();
1690        __inserted = true;
1691    }
1692    return pair<iterator, bool>(iterator(__existing_node), __inserted);
1693}
1694
1695// Prepare the container for an insertion of the value __cp_val with the hash
1696// __cp_hash. This does a lookup into the container to see if __cp_value is
1697// already present, and performs a rehash if necessary. Returns a pointer to the
1698// last occurrence of __cp_val in the map.
1699//
1700// Note that this function does forward exceptions if key_eq() throws, and never
1701// mutates __value or actually inserts into the map.
1702template <class _Tp, class _Hash, class _Equal, class _Alloc>
1703typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__next_pointer
1704__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi_prepare(
1705    size_t __cp_hash, value_type& __cp_val)
1706{
1707    size_type __bc = bucket_count();
1708    if (size()+1 > __bc * max_load_factor() || __bc == 0)
1709    {
1710        __rehash_multi(_VSTD::max<size_type>(2 * __bc + !std::__is_hash_power2(__bc),
1711                       size_type(std::ceil(float(size() + 1) / max_load_factor()))));
1712        __bc = bucket_count();
1713    }
1714    size_t __chash = std::__constrain_hash(__cp_hash, __bc);
1715    __next_pointer __pn = __bucket_list_[__chash];
1716    if (__pn != nullptr)
1717    {
1718        for (bool __found = false; __pn->__next_ != nullptr &&
1719                                   std::__constrain_hash(__pn->__next_->__hash(), __bc) == __chash;
1720                                                           __pn = __pn->__next_)
1721        {
1722            //      __found    key_eq()     action
1723            //      false       false       loop
1724            //      true        true        loop
1725            //      false       true        set __found to true
1726            //      true        false       break
1727            if (__found != (__pn->__next_->__hash() == __cp_hash &&
1728                            key_eq()(__pn->__next_->__upcast()->__value_, __cp_val)))
1729            {
1730                if (!__found)
1731                    __found = true;
1732                else
1733                    break;
1734            }
1735        }
1736    }
1737    return __pn;
1738}
1739
1740// Insert the node __cp into the container after __pn (which is the last node in
1741// the bucket that compares equal to __cp). Rehashing, and checking for
1742// uniqueness has already been performed (in __node_insert_multi_prepare), so
1743// all we need to do is update the bucket and size(). Assumes that __cp->__hash
1744// is up-to-date.
1745template <class _Tp, class _Hash, class _Equal, class _Alloc>
1746void
1747__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi_perform(
1748    __node_pointer __cp, __next_pointer __pn) _NOEXCEPT
1749{
1750    size_type __bc = bucket_count();
1751    size_t __chash = std::__constrain_hash(__cp->__hash_, __bc);
1752    if (__pn == nullptr)
1753    {
1754        __pn =__p1_.first().__ptr();
1755        __cp->__next_ = __pn->__next_;
1756        __pn->__next_ = __cp->__ptr();
1757        // fix up __bucket_list_
1758        __bucket_list_[__chash] = __pn;
1759        if (__cp->__next_ != nullptr)
1760            __bucket_list_[std::__constrain_hash(__cp->__next_->__hash(), __bc)]
1761                = __cp->__ptr();
1762    }
1763    else
1764    {
1765        __cp->__next_ = __pn->__next_;
1766        __pn->__next_ = __cp->__ptr();
1767        if (__cp->__next_ != nullptr)
1768        {
1769            size_t __nhash = std::__constrain_hash(__cp->__next_->__hash(), __bc);
1770            if (__nhash != __chash)
1771                __bucket_list_[__nhash] = __cp->__ptr();
1772        }
1773    }
1774    ++size();
1775}
1776
1777
1778template <class _Tp, class _Hash, class _Equal, class _Alloc>
1779typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
1780__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi(__node_pointer __cp)
1781{
1782    __cp->__hash_ = hash_function()(__cp->__value_);
1783    __next_pointer __pn = __node_insert_multi_prepare(__cp->__hash(), __cp->__value_);
1784    __node_insert_multi_perform(__cp, __pn);
1785
1786    return iterator(__cp->__ptr());
1787}
1788
1789template <class _Tp, class _Hash, class _Equal, class _Alloc>
1790typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
1791__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi(
1792        const_iterator __p, __node_pointer __cp)
1793{
1794    if (__p != end() && key_eq()(*__p, __cp->__value_))
1795    {
1796        __next_pointer __np = __p.__node_;
1797        __cp->__hash_ = __np->__hash();
1798        size_type __bc = bucket_count();
1799        if (size()+1 > __bc * max_load_factor() || __bc == 0)
1800        {
1801            __rehash_multi(_VSTD::max<size_type>(2 * __bc + !std::__is_hash_power2(__bc),
1802                           size_type(std::ceil(float(size() + 1) / max_load_factor()))));
1803            __bc = bucket_count();
1804        }
1805        size_t __chash = std::__constrain_hash(__cp->__hash_, __bc);
1806        __next_pointer __pp = __bucket_list_[__chash];
1807        while (__pp->__next_ != __np)
1808            __pp = __pp->__next_;
1809        __cp->__next_ = __np;
1810        __pp->__next_ = static_cast<__next_pointer>(__cp);
1811        ++size();
1812        return iterator(static_cast<__next_pointer>(__cp));
1813    }
1814    return __node_insert_multi(__cp);
1815}
1816
1817
1818
1819template <class _Tp, class _Hash, class _Equal, class _Alloc>
1820template <class _Key, class ..._Args>
1821pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
1822__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_unique_key_args(_Key const& __k, _Args&&... __args)
1823{
1824
1825    size_t __hash = hash_function()(__k);
1826    size_type __bc = bucket_count();
1827    bool __inserted = false;
1828    __next_pointer __nd;
1829    size_t __chash;
1830    if (__bc != 0)
1831    {
1832        __chash = std::__constrain_hash(__hash, __bc);
1833        __nd = __bucket_list_[__chash];
1834        if (__nd != nullptr)
1835        {
1836            for (__nd = __nd->__next_; __nd != nullptr &&
1837                (__nd->__hash() == __hash || std::__constrain_hash(__nd->__hash(), __bc) == __chash);
1838                                                           __nd = __nd->__next_)
1839            {
1840                if ((__nd->__hash() == __hash) &&
1841                    key_eq()(__nd->__upcast()->__value_, __k))
1842                    goto __done;
1843            }
1844        }
1845    }
1846    {
1847        __node_holder __h = __construct_node_hash(__hash, _VSTD::forward<_Args>(__args)...);
1848        if (size()+1 > __bc * max_load_factor() || __bc == 0)
1849        {
1850            __rehash_unique(_VSTD::max<size_type>(2 * __bc + !std::__is_hash_power2(__bc),
1851                           size_type(std::ceil(float(size() + 1) / max_load_factor()))));
1852            __bc = bucket_count();
1853            __chash = std::__constrain_hash(__hash, __bc);
1854        }
1855        // insert_after __bucket_list_[__chash], or __first_node if bucket is null
1856        __next_pointer __pn = __bucket_list_[__chash];
1857        if (__pn == nullptr)
1858        {
1859            __pn = __p1_.first().__ptr();
1860            __h->__next_ = __pn->__next_;
1861            __pn->__next_ = __h.get()->__ptr();
1862            // fix up __bucket_list_
1863            __bucket_list_[__chash] = __pn;
1864            if (__h->__next_ != nullptr)
1865                __bucket_list_[std::__constrain_hash(__h->__next_->__hash(), __bc)]
1866                    = __h.get()->__ptr();
1867        }
1868        else
1869        {
1870            __h->__next_ = __pn->__next_;
1871            __pn->__next_ = static_cast<__next_pointer>(__h.get());
1872        }
1873        __nd = static_cast<__next_pointer>(__h.release());
1874        // increment size
1875        ++size();
1876        __inserted = true;
1877    }
1878__done:
1879    return pair<iterator, bool>(iterator(__nd), __inserted);
1880}
1881
1882template <class _Tp, class _Hash, class _Equal, class _Alloc>
1883template <class... _Args>
1884pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
1885__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_unique_impl(_Args&&... __args)
1886{
1887    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
1888    pair<iterator, bool> __r = __node_insert_unique(__h.get());
1889    if (__r.second)
1890        __h.release();
1891    return __r;
1892}
1893
1894template <class _Tp, class _Hash, class _Equal, class _Alloc>
1895template <class... _Args>
1896typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
1897__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_multi(_Args&&... __args)
1898{
1899    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
1900    iterator __r = __node_insert_multi(__h.get());
1901    __h.release();
1902    return __r;
1903}
1904
1905template <class _Tp, class _Hash, class _Equal, class _Alloc>
1906template <class... _Args>
1907typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
1908__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_hint_multi(
1909        const_iterator __p, _Args&&... __args)
1910{
1911    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
1912    iterator __r = __node_insert_multi(__p, __h.get());
1913    __h.release();
1914    return __r;
1915}
1916
1917#if _LIBCPP_STD_VER >= 17
1918template <class _Tp, class _Hash, class _Equal, class _Alloc>
1919template <class _NodeHandle, class _InsertReturnType>
1920_LIBCPP_INLINE_VISIBILITY
1921_InsertReturnType
1922__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_unique(
1923    _NodeHandle&& __nh)
1924{
1925    if (__nh.empty())
1926        return _InsertReturnType{end(), false, _NodeHandle()};
1927    pair<iterator, bool> __result = __node_insert_unique(__nh.__ptr_);
1928    if (__result.second)
1929        __nh.__release_ptr();
1930    return _InsertReturnType{__result.first, __result.second, _VSTD::move(__nh)};
1931}
1932
1933template <class _Tp, class _Hash, class _Equal, class _Alloc>
1934template <class _NodeHandle>
1935_LIBCPP_INLINE_VISIBILITY
1936typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
1937__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_unique(
1938    const_iterator, _NodeHandle&& __nh)
1939{
1940    if (__nh.empty())
1941        return end();
1942    pair<iterator, bool> __result = __node_insert_unique(__nh.__ptr_);
1943    if (__result.second)
1944        __nh.__release_ptr();
1945    return __result.first;
1946}
1947
1948template <class _Tp, class _Hash, class _Equal, class _Alloc>
1949template <class _NodeHandle>
1950_LIBCPP_INLINE_VISIBILITY
1951_NodeHandle
1952__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_extract(
1953    key_type const& __key)
1954{
1955    iterator __i = find(__key);
1956    if (__i == end())
1957        return _NodeHandle();
1958    return __node_handle_extract<_NodeHandle>(__i);
1959}
1960
1961template <class _Tp, class _Hash, class _Equal, class _Alloc>
1962template <class _NodeHandle>
1963_LIBCPP_INLINE_VISIBILITY
1964_NodeHandle
1965__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_extract(
1966    const_iterator __p)
1967{
1968    allocator_type __alloc(__node_alloc());
1969    return _NodeHandle(remove(__p).release(), __alloc);
1970}
1971
1972template <class _Tp, class _Hash, class _Equal, class _Alloc>
1973template <class _Table>
1974_LIBCPP_INLINE_VISIBILITY
1975void
1976__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_merge_unique(
1977    _Table& __source)
1978{
1979    static_assert(is_same<__node, typename _Table::__node>::value, "");
1980
1981    for (typename _Table::iterator __it = __source.begin();
1982         __it != __source.end();)
1983    {
1984        __node_pointer __src_ptr = __it.__node_->__upcast();
1985        size_t __hash = hash_function()(__src_ptr->__value_);
1986        __next_pointer __existing_node =
1987            __node_insert_unique_prepare(__hash, __src_ptr->__value_);
1988        auto __prev_iter = __it++;
1989        if (__existing_node == nullptr)
1990        {
1991            (void)__source.remove(__prev_iter).release();
1992            __src_ptr->__hash_ = __hash;
1993            __node_insert_unique_perform(__src_ptr);
1994        }
1995    }
1996}
1997
1998template <class _Tp, class _Hash, class _Equal, class _Alloc>
1999template <class _NodeHandle>
2000_LIBCPP_INLINE_VISIBILITY
2001typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2002__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_multi(
2003    _NodeHandle&& __nh)
2004{
2005    if (__nh.empty())
2006        return end();
2007    iterator __result = __node_insert_multi(__nh.__ptr_);
2008    __nh.__release_ptr();
2009    return __result;
2010}
2011
2012template <class _Tp, class _Hash, class _Equal, class _Alloc>
2013template <class _NodeHandle>
2014_LIBCPP_INLINE_VISIBILITY
2015typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2016__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_multi(
2017    const_iterator __hint, _NodeHandle&& __nh)
2018{
2019    if (__nh.empty())
2020        return end();
2021    iterator __result = __node_insert_multi(__hint, __nh.__ptr_);
2022    __nh.__release_ptr();
2023    return __result;
2024}
2025
2026template <class _Tp, class _Hash, class _Equal, class _Alloc>
2027template <class _Table>
2028_LIBCPP_INLINE_VISIBILITY
2029void
2030__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_merge_multi(
2031    _Table& __source)
2032{
2033    static_assert(is_same<typename _Table::__node, __node>::value, "");
2034
2035    for (typename _Table::iterator __it = __source.begin();
2036         __it != __source.end();)
2037    {
2038        __node_pointer __src_ptr = __it.__node_->__upcast();
2039        size_t __src_hash = hash_function()(__src_ptr->__value_);
2040        __next_pointer __pn =
2041            __node_insert_multi_prepare(__src_hash, __src_ptr->__value_);
2042        (void)__source.remove(__it++).release();
2043        __src_ptr->__hash_ = __src_hash;
2044        __node_insert_multi_perform(__src_ptr, __pn);
2045    }
2046}
2047#endif // _LIBCPP_STD_VER >= 17
2048
2049template <class _Tp, class _Hash, class _Equal, class _Alloc>
2050template <bool _UniqueKeys>
2051void
2052__hash_table<_Tp, _Hash, _Equal, _Alloc>::__rehash(size_type __n)
2053_LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
2054{
2055    if (__n == 1)
2056        __n = 2;
2057    else if (__n & (__n - 1))
2058        __n = std::__next_prime(__n);
2059    size_type __bc = bucket_count();
2060    if (__n > __bc)
2061        __do_rehash<_UniqueKeys>(__n);
2062    else if (__n < __bc)
2063    {
2064        __n = _VSTD::max<size_type>
2065              (
2066                  __n,
2067                  std::__is_hash_power2(__bc) ? std::__next_hash_pow2(size_t(std::ceil(float(size()) / max_load_factor()))) :
2068                                           std::__next_prime(size_t(std::ceil(float(size()) / max_load_factor())))
2069              );
2070        if (__n < __bc)
2071            __do_rehash<_UniqueKeys>(__n);
2072    }
2073}
2074
2075template <class _Tp, class _Hash, class _Equal, class _Alloc>
2076template <bool _UniqueKeys>
2077void
2078__hash_table<_Tp, _Hash, _Equal, _Alloc>::__do_rehash(size_type __nbc)
2079{
2080    __pointer_allocator& __npa = __bucket_list_.get_deleter().__alloc();
2081    __bucket_list_.reset(__nbc > 0 ?
2082                      __pointer_alloc_traits::allocate(__npa, __nbc) : nullptr);
2083    __bucket_list_.get_deleter().size() = __nbc;
2084    if (__nbc > 0)
2085    {
2086        for (size_type __i = 0; __i < __nbc; ++__i)
2087            __bucket_list_[__i] = nullptr;
2088        __next_pointer __pp = __p1_.first().__ptr();
2089        __next_pointer __cp = __pp->__next_;
2090        if (__cp != nullptr)
2091        {
2092            size_type __chash = std::__constrain_hash(__cp->__hash(), __nbc);
2093            __bucket_list_[__chash] = __pp;
2094            size_type __phash = __chash;
2095            for (__pp = __cp, void(), __cp = __cp->__next_; __cp != nullptr;
2096                                                           __cp = __pp->__next_)
2097            {
2098                __chash = std::__constrain_hash(__cp->__hash(), __nbc);
2099                if (__chash == __phash)
2100                    __pp = __cp;
2101                else
2102                {
2103                    if (__bucket_list_[__chash] == nullptr)
2104                    {
2105                        __bucket_list_[__chash] = __pp;
2106                        __pp = __cp;
2107                        __phash = __chash;
2108                    }
2109                    else
2110                    {
2111                        __next_pointer __np = __cp;
2112                        if _LIBCPP_CONSTEXPR_SINCE_CXX17 (!_UniqueKeys)
2113                        {
2114                            for (; __np->__next_ != nullptr &&
2115                                   key_eq()(__cp->__upcast()->__value_,
2116                                            __np->__next_->__upcast()->__value_);
2117                                                               __np = __np->__next_)
2118                                ;
2119                        }
2120                        __pp->__next_ = __np->__next_;
2121                        __np->__next_ = __bucket_list_[__chash]->__next_;
2122                        __bucket_list_[__chash]->__next_ = __cp;
2123
2124                    }
2125                }
2126            }
2127        }
2128    }
2129}
2130
2131template <class _Tp, class _Hash, class _Equal, class _Alloc>
2132template <class _Key>
2133typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2134__hash_table<_Tp, _Hash, _Equal, _Alloc>::find(const _Key& __k)
2135{
2136    size_t __hash = hash_function()(__k);
2137    size_type __bc = bucket_count();
2138    if (__bc != 0)
2139    {
2140        size_t __chash = std::__constrain_hash(__hash, __bc);
2141        __next_pointer __nd = __bucket_list_[__chash];
2142        if (__nd != nullptr)
2143        {
2144            for (__nd = __nd->__next_; __nd != nullptr &&
2145                (__nd->__hash() == __hash
2146                  || std::__constrain_hash(__nd->__hash(), __bc) == __chash);
2147                                                           __nd = __nd->__next_)
2148            {
2149                if ((__nd->__hash() == __hash)
2150                    && key_eq()(__nd->__upcast()->__value_, __k))
2151                    return iterator(__nd);
2152            }
2153        }
2154    }
2155    return end();
2156}
2157
2158template <class _Tp, class _Hash, class _Equal, class _Alloc>
2159template <class _Key>
2160typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
2161__hash_table<_Tp, _Hash, _Equal, _Alloc>::find(const _Key& __k) const
2162{
2163    size_t __hash = hash_function()(__k);
2164    size_type __bc = bucket_count();
2165    if (__bc != 0)
2166    {
2167        size_t __chash = std::__constrain_hash(__hash, __bc);
2168        __next_pointer __nd = __bucket_list_[__chash];
2169        if (__nd != nullptr)
2170        {
2171            for (__nd = __nd->__next_; __nd != nullptr &&
2172                (__hash == __nd->__hash()
2173                    || std::__constrain_hash(__nd->__hash(), __bc) == __chash);
2174                                                           __nd = __nd->__next_)
2175            {
2176                if ((__nd->__hash() == __hash)
2177                    && key_eq()(__nd->__upcast()->__value_, __k))
2178                    return const_iterator(__nd);
2179            }
2180        }
2181
2182    }
2183    return end();
2184}
2185
2186template <class _Tp, class _Hash, class _Equal, class _Alloc>
2187template <class ..._Args>
2188typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
2189__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node(_Args&& ...__args)
2190{
2191    static_assert(!__is_hash_value_type<_Args...>::value,
2192                  "Construct cannot be called with a hash value type");
2193    __node_allocator& __na = __node_alloc();
2194    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
2195    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), _VSTD::forward<_Args>(__args)...);
2196    __h.get_deleter().__value_constructed = true;
2197    __h->__hash_ = hash_function()(__h->__value_);
2198    __h->__next_ = nullptr;
2199    return __h;
2200}
2201
2202template <class _Tp, class _Hash, class _Equal, class _Alloc>
2203template <class _First, class ..._Rest>
2204typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
2205__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node_hash(
2206    size_t __hash, _First&& __f, _Rest&& ...__rest)
2207{
2208    static_assert(!__is_hash_value_type<_First, _Rest...>::value,
2209                  "Construct cannot be called with a hash value type");
2210    __node_allocator& __na = __node_alloc();
2211    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
2212    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_),
2213                             _VSTD::forward<_First>(__f),
2214                             _VSTD::forward<_Rest>(__rest)...);
2215    __h.get_deleter().__value_constructed = true;
2216    __h->__hash_ = __hash;
2217    __h->__next_ = nullptr;
2218    return __h;
2219}
2220
2221template <class _Tp, class _Hash, class _Equal, class _Alloc>
2222typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2223__hash_table<_Tp, _Hash, _Equal, _Alloc>::erase(const_iterator __p)
2224{
2225    __next_pointer __np = __p.__node_;
2226    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__p != end(),
2227        "unordered container::erase(iterator) called with a non-dereferenceable iterator");
2228    iterator __r(__np);
2229    ++__r;
2230    remove(__p);
2231    return __r;
2232}
2233
2234template <class _Tp, class _Hash, class _Equal, class _Alloc>
2235typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2236__hash_table<_Tp, _Hash, _Equal, _Alloc>::erase(const_iterator __first,
2237                                                const_iterator __last)
2238{
2239    for (const_iterator __p = __first; __first != __last; __p = __first)
2240    {
2241        ++__first;
2242        erase(__p);
2243    }
2244    __next_pointer __np = __last.__node_;
2245    return iterator (__np);
2246}
2247
2248template <class _Tp, class _Hash, class _Equal, class _Alloc>
2249template <class _Key>
2250typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
2251__hash_table<_Tp, _Hash, _Equal, _Alloc>::__erase_unique(const _Key& __k)
2252{
2253    iterator __i = find(__k);
2254    if (__i == end())
2255        return 0;
2256    erase(__i);
2257    return 1;
2258}
2259
2260template <class _Tp, class _Hash, class _Equal, class _Alloc>
2261template <class _Key>
2262typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
2263__hash_table<_Tp, _Hash, _Equal, _Alloc>::__erase_multi(const _Key& __k)
2264{
2265    size_type __r = 0;
2266    iterator __i = find(__k);
2267    if (__i != end())
2268    {
2269        iterator __e = end();
2270        do
2271        {
2272            erase(__i++);
2273            ++__r;
2274        } while (__i != __e && key_eq()(*__i, __k));
2275    }
2276    return __r;
2277}
2278
2279template <class _Tp, class _Hash, class _Equal, class _Alloc>
2280typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
2281__hash_table<_Tp, _Hash, _Equal, _Alloc>::remove(const_iterator __p) _NOEXCEPT
2282{
2283    // current node
2284    __next_pointer __cn = __p.__node_;
2285    size_type __bc = bucket_count();
2286    size_t __chash = std::__constrain_hash(__cn->__hash(), __bc);
2287    // find previous node
2288    __next_pointer __pn = __bucket_list_[__chash];
2289    for (; __pn->__next_ != __cn; __pn = __pn->__next_)
2290        ;
2291    // Fix up __bucket_list_
2292        // if __pn is not in same bucket (before begin is not in same bucket) &&
2293        //    if __cn->__next_ is not in same bucket (nullptr is not in same bucket)
2294    if (__pn == __p1_.first().__ptr()
2295            || std::__constrain_hash(__pn->__hash(), __bc) != __chash)
2296    {
2297        if (__cn->__next_ == nullptr
2298            || std::__constrain_hash(__cn->__next_->__hash(), __bc) != __chash)
2299            __bucket_list_[__chash] = nullptr;
2300    }
2301        // if __cn->__next_ is not in same bucket (nullptr is in same bucket)
2302    if (__cn->__next_ != nullptr)
2303    {
2304        size_t __nhash = std::__constrain_hash(__cn->__next_->__hash(), __bc);
2305        if (__nhash != __chash)
2306            __bucket_list_[__nhash] = __pn;
2307    }
2308    // remove __cn
2309    __pn->__next_ = __cn->__next_;
2310    __cn->__next_ = nullptr;
2311    --size();
2312    return __node_holder(__cn->__upcast(), _Dp(__node_alloc(), true));
2313}
2314
2315template <class _Tp, class _Hash, class _Equal, class _Alloc>
2316template <class _Key>
2317inline
2318typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
2319__hash_table<_Tp, _Hash, _Equal, _Alloc>::__count_unique(const _Key& __k) const
2320{
2321    return static_cast<size_type>(find(__k) != end());
2322}
2323
2324template <class _Tp, class _Hash, class _Equal, class _Alloc>
2325template <class _Key>
2326typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
2327__hash_table<_Tp, _Hash, _Equal, _Alloc>::__count_multi(const _Key& __k) const
2328{
2329    size_type __r = 0;
2330    const_iterator __i = find(__k);
2331    if (__i != end())
2332    {
2333        const_iterator __e = end();
2334        do
2335        {
2336            ++__i;
2337            ++__r;
2338        } while (__i != __e && key_eq()(*__i, __k));
2339    }
2340    return __r;
2341}
2342
2343template <class _Tp, class _Hash, class _Equal, class _Alloc>
2344template <class _Key>
2345pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator,
2346     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator>
2347__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_unique(
2348        const _Key& __k)
2349{
2350    iterator __i = find(__k);
2351    iterator __j = __i;
2352    if (__i != end())
2353        ++__j;
2354    return pair<iterator, iterator>(__i, __j);
2355}
2356
2357template <class _Tp, class _Hash, class _Equal, class _Alloc>
2358template <class _Key>
2359pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator,
2360     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator>
2361__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_unique(
2362        const _Key& __k) const
2363{
2364    const_iterator __i = find(__k);
2365    const_iterator __j = __i;
2366    if (__i != end())
2367        ++__j;
2368    return pair<const_iterator, const_iterator>(__i, __j);
2369}
2370
2371template <class _Tp, class _Hash, class _Equal, class _Alloc>
2372template <class _Key>
2373pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator,
2374     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator>
2375__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_multi(
2376        const _Key& __k)
2377{
2378    iterator __i = find(__k);
2379    iterator __j = __i;
2380    if (__i != end())
2381    {
2382        iterator __e = end();
2383        do
2384        {
2385            ++__j;
2386        } while (__j != __e && key_eq()(*__j, __k));
2387    }
2388    return pair<iterator, iterator>(__i, __j);
2389}
2390
2391template <class _Tp, class _Hash, class _Equal, class _Alloc>
2392template <class _Key>
2393pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator,
2394     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator>
2395__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_multi(
2396        const _Key& __k) const
2397{
2398    const_iterator __i = find(__k);
2399    const_iterator __j = __i;
2400    if (__i != end())
2401    {
2402        const_iterator __e = end();
2403        do
2404        {
2405            ++__j;
2406        } while (__j != __e && key_eq()(*__j, __k));
2407    }
2408    return pair<const_iterator, const_iterator>(__i, __j);
2409}
2410
2411template <class _Tp, class _Hash, class _Equal, class _Alloc>
2412void
2413__hash_table<_Tp, _Hash, _Equal, _Alloc>::swap(__hash_table& __u)
2414#if _LIBCPP_STD_VER <= 11
2415    _NOEXCEPT_(
2416        __is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value
2417        && (!allocator_traits<__pointer_allocator>::propagate_on_container_swap::value
2418              || __is_nothrow_swappable<__pointer_allocator>::value)
2419        && (!__node_traits::propagate_on_container_swap::value
2420              || __is_nothrow_swappable<__node_allocator>::value)
2421            )
2422#else
2423  _NOEXCEPT_(__is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value)
2424#endif
2425{
2426    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(__node_traits::propagate_on_container_swap::value ||
2427                                        this->__node_alloc() == __u.__node_alloc(),
2428                                        "unordered container::swap: Either propagate_on_container_swap "
2429                                        "must be true or the allocators must compare equal");
2430    {
2431    __node_pointer_pointer __npp = __bucket_list_.release();
2432    __bucket_list_.reset(__u.__bucket_list_.release());
2433    __u.__bucket_list_.reset(__npp);
2434    }
2435    _VSTD::swap(__bucket_list_.get_deleter().size(), __u.__bucket_list_.get_deleter().size());
2436    _VSTD::__swap_allocator(__bucket_list_.get_deleter().__alloc(),
2437             __u.__bucket_list_.get_deleter().__alloc());
2438    _VSTD::__swap_allocator(__node_alloc(), __u.__node_alloc());
2439    _VSTD::swap(__p1_.first().__next_, __u.__p1_.first().__next_);
2440    __p2_.swap(__u.__p2_);
2441    __p3_.swap(__u.__p3_);
2442    if (size() > 0)
2443        __bucket_list_[std::__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
2444            __p1_.first().__ptr();
2445    if (__u.size() > 0)
2446        __u.__bucket_list_[std::__constrain_hash(__u.__p1_.first().__next_->__hash(), __u.bucket_count())] =
2447            __u.__p1_.first().__ptr();
2448}
2449
2450template <class _Tp, class _Hash, class _Equal, class _Alloc>
2451typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
2452__hash_table<_Tp, _Hash, _Equal, _Alloc>::bucket_size(size_type __n) const
2453{
2454    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__n < bucket_count(),
2455        "unordered container::bucket_size(n) called with n >= bucket_count()");
2456    __next_pointer __np = __bucket_list_[__n];
2457    size_type __bc = bucket_count();
2458    size_type __r = 0;
2459    if (__np != nullptr)
2460    {
2461        for (__np = __np->__next_; __np != nullptr &&
2462                                   std::__constrain_hash(__np->__hash(), __bc) == __n;
2463                                                         __np = __np->__next_, (void) ++__r)
2464            ;
2465    }
2466    return __r;
2467}
2468
2469template <class _Tp, class _Hash, class _Equal, class _Alloc>
2470inline _LIBCPP_INLINE_VISIBILITY
2471void
2472swap(__hash_table<_Tp, _Hash, _Equal, _Alloc>& __x,
2473     __hash_table<_Tp, _Hash, _Equal, _Alloc>& __y)
2474    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
2475{
2476    __x.swap(__y);
2477}
2478
2479_LIBCPP_END_NAMESPACE_STD
2480
2481_LIBCPP_POP_MACROS
2482
2483#endif // _LIBCPP___HASH_TABLE
2484