1 // hashtable.h header -*- C++ -*-
3 // Copyright (C) 2007-2015 Free Software Foundation, Inc.
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
25 /** @file bits/hashtable.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{unordered_map, unordered_set}
31 #define _HASHTABLE_H 1
33 #pragma GCC system_header
35 #include <bits/hashtable_policy.h>
37 namespace std
_GLIBCXX_VISIBILITY(default)
39 _GLIBCXX_BEGIN_NAMESPACE_VERSION
41 template<typename _Tp
, typename _Hash
>
43 = __not_
<__and_
<// Do not cache for fast hasher.
44 __is_fast_hash
<_Hash
>,
45 // Mandatory to have erase not throwing.
46 __detail::__is_noexcept_hash
<_Tp
, _Hash
>>>;
49 * Primary class template _Hashtable.
51 * @ingroup hashtable-detail
53 * @tparam _Value CopyConstructible type.
55 * @tparam _Key CopyConstructible type.
57 * @tparam _Alloc An allocator type
58 * ([lib.allocator.requirements]) whose _Alloc::value_type is
59 * _Value. As a conforming extension, we allow for
60 * _Alloc::value_type != _Value.
62 * @tparam _ExtractKey Function object that takes an object of type
63 * _Value and returns a value of type _Key.
65 * @tparam _Equal Function object that takes two objects of type k
66 * and returns a bool-like value that is true if the two objects
67 * are considered equal.
69 * @tparam _H1 The hash function. A unary function object with
70 * argument type _Key and result type size_t. Return values should
71 * be distributed over the entire range [0, numeric_limits<size_t>:::max()].
73 * @tparam _H2 The range-hashing function (in the terminology of
74 * Tavori and Dreizin). A binary function object whose argument
75 * types and result type are all size_t. Given arguments r and N,
76 * the return value is in the range [0, N).
78 * @tparam _Hash The ranged hash function (Tavori and Dreizin). A
79 * binary function whose argument types are _Key and size_t and
80 * whose result type is size_t. Given arguments k and N, the
81 * return value is in the range [0, N). Default: hash(k, N) =
82 * h2(h1(k), N). If _Hash is anything other than the default, _H1
83 * and _H2 are ignored.
85 * @tparam _RehashPolicy Policy class with three members, all of
86 * which govern the bucket count. _M_next_bkt(n) returns a bucket
87 * count no smaller than n. _M_bkt_for_elements(n) returns a
88 * bucket count appropriate for an element count of n.
89 * _M_need_rehash(n_bkt, n_elt, n_ins) determines whether, if the
90 * current bucket count is n_bkt and the current element count is
91 * n_elt, we need to increase the bucket count. If so, returns
92 * make_pair(true, n), where n is the new bucket count. If not,
93 * returns make_pair(false, <anything>)
95 * @tparam _Traits Compile-time class with three boolean
96 * std::integral_constant members: __cache_hash_code, __constant_iterators,
99 * Each _Hashtable data structure has:
101 * - _Bucket[] _M_buckets
102 * - _Hash_node_base _M_before_begin
103 * - size_type _M_bucket_count
104 * - size_type _M_element_count
106 * with _Bucket being _Hash_node* and _Hash_node containing:
108 * - _Hash_node* _M_next
110 * - size_t _M_hash_code if cache_hash_code is true
112 * In terms of Standard containers the hashtable is like the aggregation of:
114 * - std::forward_list<_Node> containing the elements
115 * - std::vector<std::forward_list<_Node>::iterator> representing the buckets
117 * The non-empty buckets contain the node before the first node in the
118 * bucket. This design makes it possible to implement something like a
119 * std::forward_list::insert_after on container insertion and
120 * std::forward_list::erase_after on container erase
121 * calls. _M_before_begin is equivalent to
122 * std::forward_list::before_begin. Empty buckets contain
123 * nullptr. Note that one of the non-empty buckets contains
124 * &_M_before_begin which is not a dereferenceable node so the
125 * node pointer in a bucket shall never be dereferenced, only its
128 * Walking through a bucket's nodes requires a check on the hash code to
129 * see if each node is still in the bucket. Such a design assumes a
130 * quite efficient hash functor and is one of the reasons it is
131 * highly advisable to set __cache_hash_code to true.
133 * The container iterators are simply built from nodes. This way
134 * incrementing the iterator is perfectly efficient independent of
135 * how many empty buckets there are in the container.
137 * On insert we compute the element's hash code and use it to find the
138 * bucket index. If the element must be inserted in an empty bucket
139 * we add it at the beginning of the singly linked list and make the
140 * bucket point to _M_before_begin. The bucket that used to point to
141 * _M_before_begin, if any, is updated to point to its new before
144 * On erase, the simple iterator design requires using the hash
145 * functor to get the index of the bucket to update. For this
146 * reason, when __cache_hash_code is set to false the hash functor must
147 * not throw and this is enforced by a static assertion.
149 * Functionality is implemented by decomposition into base classes,
150 * where the derived _Hashtable class is used in _Map_base,
151 * _Insert, _Rehash_base, and _Equality base classes to access the
152 * "this" pointer. _Hashtable_base is used in the base classes as a
153 * non-recursive, fully-completed-type so that detailed nested type
154 * information, such as iterator type and node type, can be
155 * used. This is similar to the "Curiously Recurring Template
156 * Pattern" (CRTP) technique, but uses a reconstructed, not
157 * explicitly passed, template pattern.
159 * Base class templates are:
160 * - __detail::_Hashtable_base
161 * - __detail::_Map_base
162 * - __detail::_Insert
163 * - __detail::_Rehash_base
164 * - __detail::_Equality
166 template<typename _Key
, typename _Value
, typename _Alloc
,
167 typename _ExtractKey
, typename _Equal
,
168 typename _H1
, typename _H2
, typename _Hash
,
169 typename _RehashPolicy
, typename _Traits
>
171 : public __detail::_Hashtable_base
<_Key
, _Value
, _ExtractKey
, _Equal
,
172 _H1
, _H2
, _Hash
, _Traits
>,
173 public __detail::_Map_base
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
174 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>,
175 public __detail::_Insert
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
176 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>,
177 public __detail::_Rehash_base
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
178 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>,
179 public __detail::_Equality
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
180 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>,
181 private __detail::_Hashtable_alloc
<
182 typename __alloctr_rebind
<_Alloc
,
183 __detail::_Hash_node
<_Value
,
184 _Traits::__hash_cached::value
> >::__type
>
186 using __traits_type
= _Traits
;
187 using __hash_cached
= typename
__traits_type::__hash_cached
;
188 using __node_type
= __detail::_Hash_node
<_Value
, __hash_cached::value
>;
189 using __node_alloc_type
=
190 typename __alloctr_rebind
<_Alloc
, __node_type
>::__type
;
192 using __hashtable_alloc
= __detail::_Hashtable_alloc
<__node_alloc_type
>;
194 using __value_alloc_traits
=
195 typename
__hashtable_alloc::__value_alloc_traits
;
196 using __node_alloc_traits
=
197 typename
__hashtable_alloc::__node_alloc_traits
;
198 using __node_base
= typename
__hashtable_alloc::__node_base
;
199 using __bucket_type
= typename
__hashtable_alloc::__bucket_type
;
202 typedef _Key key_type
;
203 typedef _Value value_type
;
204 typedef _Alloc allocator_type
;
205 typedef _Equal key_equal
;
207 // mapped_type, if present, comes from _Map_base.
208 // hasher, if present, comes from _Hash_code_base/_Hashtable_base.
209 typedef typename
__value_alloc_traits::pointer pointer
;
210 typedef typename
__value_alloc_traits::const_pointer const_pointer
;
211 typedef value_type
& reference
;
212 typedef const value_type
& const_reference
;
215 using __rehash_type
= _RehashPolicy
;
216 using __rehash_state
= typename
__rehash_type::_State
;
218 using __constant_iterators
= typename
__traits_type::__constant_iterators
;
219 using __unique_keys
= typename
__traits_type::__unique_keys
;
221 using __key_extract
= typename
std::conditional
<
222 __constant_iterators::value
,
224 __detail::_Select1st
>::type
;
226 using __hashtable_base
= __detail::
227 _Hashtable_base
<_Key
, _Value
, _ExtractKey
,
228 _Equal
, _H1
, _H2
, _Hash
, _Traits
>;
230 using __hash_code_base
= typename
__hashtable_base::__hash_code_base
;
231 using __hash_code
= typename
__hashtable_base::__hash_code
;
232 using __ireturn_type
= typename
__hashtable_base::__ireturn_type
;
234 using __map_base
= __detail::_Map_base
<_Key
, _Value
, _Alloc
, _ExtractKey
,
235 _Equal
, _H1
, _H2
, _Hash
,
236 _RehashPolicy
, _Traits
>;
238 using __rehash_base
= __detail::_Rehash_base
<_Key
, _Value
, _Alloc
,
241 _RehashPolicy
, _Traits
>;
243 using __eq_base
= __detail::_Equality
<_Key
, _Value
, _Alloc
, _ExtractKey
,
244 _Equal
, _H1
, _H2
, _Hash
,
245 _RehashPolicy
, _Traits
>;
247 using __reuse_or_alloc_node_type
=
248 __detail::_ReuseOrAllocNode
<__node_alloc_type
>;
250 // Metaprogramming for picking apart hash caching.
251 template<typename _Cond
>
252 using __if_hash_cached
= __or_
<__not_
<__hash_cached
>, _Cond
>;
254 template<typename _Cond
>
255 using __if_hash_not_cached
= __or_
<__hash_cached
, _Cond
>;
257 // Compile-time diagnostics.
259 // _Hash_code_base has everything protected, so use this derived type to
261 struct __hash_code_base_access
: __hash_code_base
262 { using __hash_code_base::_M_bucket_index
; };
264 // Getting a bucket index from a node shall not throw because it is used
265 // in methods (erase, swap...) that shall not throw.
266 static_assert(noexcept(declval
<const __hash_code_base_access
&>()
267 ._M_bucket_index((const __node_type
*)nullptr,
269 "Cache the hash code or qualify your functors involved"
270 " in hash code and bucket index computation with noexcept");
272 // Following two static assertions are necessary to guarantee
273 // that local_iterator will be default constructible.
275 // When hash codes are cached local iterator inherits from H2 functor
276 // which must then be default constructible.
277 static_assert(__if_hash_cached
<is_default_constructible
<_H2
>>::value
,
278 "Functor used to map hash code to bucket index"
279 " must be default constructible");
281 template<typename _Keya
, typename _Valuea
, typename _Alloca
,
282 typename _ExtractKeya
, typename _Equala
,
283 typename _H1a
, typename _H2a
, typename _Hasha
,
284 typename _RehashPolicya
, typename _Traitsa
,
286 friend struct __detail::_Map_base
;
288 template<typename _Keya
, typename _Valuea
, typename _Alloca
,
289 typename _ExtractKeya
, typename _Equala
,
290 typename _H1a
, typename _H2a
, typename _Hasha
,
291 typename _RehashPolicya
, typename _Traitsa
>
292 friend struct __detail::_Insert_base
;
294 template<typename _Keya
, typename _Valuea
, typename _Alloca
,
295 typename _ExtractKeya
, typename _Equala
,
296 typename _H1a
, typename _H2a
, typename _Hasha
,
297 typename _RehashPolicya
, typename _Traitsa
,
298 bool _Constant_iteratorsa
, bool _Unique_keysa
>
299 friend struct __detail::_Insert
;
302 using size_type
= typename
__hashtable_base::size_type
;
303 using difference_type
= typename
__hashtable_base::difference_type
;
305 using iterator
= typename
__hashtable_base::iterator
;
306 using const_iterator
= typename
__hashtable_base::const_iterator
;
308 using local_iterator
= typename
__hashtable_base::local_iterator
;
309 using const_local_iterator
= typename
__hashtable_base::
310 const_local_iterator
;
313 __bucket_type
* _M_buckets
= &_M_single_bucket
;
314 size_type _M_bucket_count
= 1;
315 __node_base _M_before_begin
;
316 size_type _M_element_count
= 0;
317 _RehashPolicy _M_rehash_policy
;
319 // A single bucket used when only need for 1 bucket. Especially
320 // interesting in move semantic to leave hashtable with only 1 buckets
321 // which is not allocated so that we can have those operations noexcept
323 // Note that we can't leave hashtable with 0 bucket without adding
324 // numerous checks in the code to avoid 0 modulus.
325 __bucket_type _M_single_bucket
= nullptr;
328 _M_uses_single_bucket(__bucket_type
* __bkts
) const
329 { return __builtin_expect(__bkts
== &_M_single_bucket
, false); }
332 _M_uses_single_bucket() const
333 { return _M_uses_single_bucket(_M_buckets
); }
336 _M_base_alloc() { return *this; }
339 _M_allocate_buckets(size_type __n
)
341 if (__builtin_expect(__n
== 1, false))
343 _M_single_bucket
= nullptr;
344 return &_M_single_bucket
;
347 return __hashtable_alloc::_M_allocate_buckets(__n
);
351 _M_deallocate_buckets(__bucket_type
* __bkts
, size_type __n
)
353 if (_M_uses_single_bucket(__bkts
))
356 __hashtable_alloc::_M_deallocate_buckets(__bkts
, __n
);
360 _M_deallocate_buckets()
361 { _M_deallocate_buckets(_M_buckets
, _M_bucket_count
); }
363 // Gets bucket begin, deals with the fact that non-empty buckets contain
364 // their before begin node.
366 _M_bucket_begin(size_type __bkt
) const;
370 { return static_cast<__node_type
*>(_M_before_begin
._M_nxt
); }
372 template<typename _NodeGenerator
>
374 _M_assign(const _Hashtable
&, const _NodeGenerator
&);
377 _M_move_assign(_Hashtable
&&, std::true_type
);
380 _M_move_assign(_Hashtable
&&, std::false_type
);
385 _Hashtable(const _H1
& __h1
, const _H2
& __h2
, const _Hash
& __h
,
386 const _Equal
& __eq
, const _ExtractKey
& __exk
,
387 const allocator_type
& __a
)
388 : __hashtable_base(__exk
, __h1
, __h2
, __h
, __eq
),
389 __hashtable_alloc(__node_alloc_type(__a
))
393 // Constructor, destructor, assignment, swap
394 _Hashtable() = default;
395 _Hashtable(size_type __bucket_hint
,
396 const _H1
&, const _H2
&, const _Hash
&,
397 const _Equal
&, const _ExtractKey
&,
398 const allocator_type
&);
400 template<typename _InputIterator
>
401 _Hashtable(_InputIterator __first
, _InputIterator __last
,
402 size_type __bucket_hint
,
403 const _H1
&, const _H2
&, const _Hash
&,
404 const _Equal
&, const _ExtractKey
&,
405 const allocator_type
&);
407 _Hashtable(const _Hashtable
&);
409 _Hashtable(_Hashtable
&&) noexcept
;
411 _Hashtable(const _Hashtable
&, const allocator_type
&);
413 _Hashtable(_Hashtable
&&, const allocator_type
&);
415 // Use delegating constructors.
417 _Hashtable(const allocator_type
& __a
)
418 : __hashtable_alloc(__node_alloc_type(__a
))
422 _Hashtable(size_type __n
,
423 const _H1
& __hf
= _H1(),
424 const key_equal
& __eql
= key_equal(),
425 const allocator_type
& __a
= allocator_type())
426 : _Hashtable(__n
, __hf
, _H2(), _Hash(), __eql
,
427 __key_extract(), __a
)
430 template<typename _InputIterator
>
431 _Hashtable(_InputIterator __f
, _InputIterator __l
,
433 const _H1
& __hf
= _H1(),
434 const key_equal
& __eql
= key_equal(),
435 const allocator_type
& __a
= allocator_type())
436 : _Hashtable(__f
, __l
, __n
, __hf
, _H2(), _Hash(), __eql
,
437 __key_extract(), __a
)
440 _Hashtable(initializer_list
<value_type
> __l
,
442 const _H1
& __hf
= _H1(),
443 const key_equal
& __eql
= key_equal(),
444 const allocator_type
& __a
= allocator_type())
445 : _Hashtable(__l
.begin(), __l
.end(), __n
, __hf
, _H2(), _Hash(), __eql
,
446 __key_extract(), __a
)
450 operator=(const _Hashtable
& __ht
);
453 operator=(_Hashtable
&& __ht
)
454 noexcept(__node_alloc_traits::_S_nothrow_move())
456 constexpr bool __move_storage
=
457 __node_alloc_traits::_S_propagate_on_move_assign()
458 || __node_alloc_traits::_S_always_equal();
459 _M_move_assign(std::move(__ht
),
460 integral_constant
<bool, __move_storage
>());
465 operator=(initializer_list
<value_type
> __l
)
467 __reuse_or_alloc_node_type
__roan(_M_begin(), *this);
468 _M_before_begin
._M_nxt
= nullptr;
470 this->_M_insert_range(__l
.begin(), __l
.end(), __roan
);
474 ~_Hashtable() noexcept
;
478 noexcept(__node_alloc_traits::_S_nothrow_swap());
480 // Basic container operations
483 { return iterator(_M_begin()); }
486 begin() const noexcept
487 { return const_iterator(_M_begin()); }
491 { return iterator(nullptr); }
495 { return const_iterator(nullptr); }
498 cbegin() const noexcept
499 { return const_iterator(_M_begin()); }
502 cend() const noexcept
503 { return const_iterator(nullptr); }
506 size() const noexcept
507 { return _M_element_count
; }
510 empty() const noexcept
511 { return size() == 0; }
514 get_allocator() const noexcept
515 { return allocator_type(this->_M_node_allocator()); }
518 max_size() const noexcept
519 { return __node_alloc_traits::max_size(this->_M_node_allocator()); }
524 { return this->_M_eq(); }
526 // hash_function, if present, comes from _Hash_code_base.
530 bucket_count() const noexcept
531 { return _M_bucket_count
; }
534 max_bucket_count() const noexcept
535 { return max_size(); }
538 bucket_size(size_type __n
) const
539 { return std::distance(begin(__n
), end(__n
)); }
542 bucket(const key_type
& __k
) const
543 { return _M_bucket_index(__k
, this->_M_hash_code(__k
)); }
548 return local_iterator(*this, _M_bucket_begin(__n
),
549 __n
, _M_bucket_count
);
554 { return local_iterator(*this, nullptr, __n
, _M_bucket_count
); }
557 begin(size_type __n
) const
559 return const_local_iterator(*this, _M_bucket_begin(__n
),
560 __n
, _M_bucket_count
);
564 end(size_type __n
) const
565 { return const_local_iterator(*this, nullptr, __n
, _M_bucket_count
); }
569 cbegin(size_type __n
) const
571 return const_local_iterator(*this, _M_bucket_begin(__n
),
572 __n
, _M_bucket_count
);
576 cend(size_type __n
) const
577 { return const_local_iterator(*this, nullptr, __n
, _M_bucket_count
); }
580 load_factor() const noexcept
582 return static_cast<float>(size()) / static_cast<float>(bucket_count());
585 // max_load_factor, if present, comes from _Rehash_base.
587 // Generalization of max_load_factor. Extension, not found in
588 // TR1. Only useful if _RehashPolicy is something other than
591 __rehash_policy() const
592 { return _M_rehash_policy
; }
595 __rehash_policy(const _RehashPolicy
&);
599 find(const key_type
& __k
);
602 find(const key_type
& __k
) const;
605 count(const key_type
& __k
) const;
607 std::pair
<iterator
, iterator
>
608 equal_range(const key_type
& __k
);
610 std::pair
<const_iterator
, const_iterator
>
611 equal_range(const key_type
& __k
) const;
614 // Bucket index computation helpers.
616 _M_bucket_index(__node_type
* __n
) const noexcept
617 { return __hash_code_base::_M_bucket_index(__n
, _M_bucket_count
); }
620 _M_bucket_index(const key_type
& __k
, __hash_code __c
) const
621 { return __hash_code_base::_M_bucket_index(__k
, __c
, _M_bucket_count
); }
623 // Find and insert helper functions and types
624 // Find the node before the one matching the criteria.
626 _M_find_before_node(size_type
, const key_type
&, __hash_code
) const;
629 _M_find_node(size_type __bkt
, const key_type
& __key
,
630 __hash_code __c
) const
632 __node_base
* __before_n
= _M_find_before_node(__bkt
, __key
, __c
);
634 return static_cast<__node_type
*>(__before_n
->_M_nxt
);
638 // Insert a node at the beginning of a bucket.
640 _M_insert_bucket_begin(size_type
, __node_type
*);
642 // Remove the bucket first node
644 _M_remove_bucket_begin(size_type __bkt
, __node_type
* __next_n
,
645 size_type __next_bkt
);
647 // Get the node before __n in the bucket __bkt
649 _M_get_previous_node(size_type __bkt
, __node_base
* __n
);
651 // Insert node with hash code __code, in bucket bkt if no rehash (assumes
652 // no element with its key already present). Take ownership of the node,
653 // deallocate it on exception.
655 _M_insert_unique_node(size_type __bkt
, __hash_code __code
,
658 // Insert node with hash code __code. Take ownership of the node,
659 // deallocate it on exception.
661 _M_insert_multi_node(__node_type
* __hint
,
662 __hash_code __code
, __node_type
* __n
);
664 template<typename
... _Args
>
665 std::pair
<iterator
, bool>
666 _M_emplace(std::true_type
, _Args
&&... __args
);
668 template<typename
... _Args
>
670 _M_emplace(std::false_type __uk
, _Args
&&... __args
)
671 { return _M_emplace(cend(), __uk
, std::forward
<_Args
>(__args
)...); }
673 // Emplace with hint, useless when keys are unique.
674 template<typename
... _Args
>
676 _M_emplace(const_iterator
, std::true_type __uk
, _Args
&&... __args
)
677 { return _M_emplace(__uk
, std::forward
<_Args
>(__args
)...).first
; }
679 template<typename
... _Args
>
681 _M_emplace(const_iterator
, std::false_type
, _Args
&&... __args
);
683 template<typename _Arg
, typename _NodeGenerator
>
684 std::pair
<iterator
, bool>
685 _M_insert(_Arg
&&, const _NodeGenerator
&, std::true_type
);
687 template<typename _Arg
, typename _NodeGenerator
>
689 _M_insert(_Arg
&& __arg
, const _NodeGenerator
& __node_gen
,
690 std::false_type __uk
)
692 return _M_insert(cend(), std::forward
<_Arg
>(__arg
), __node_gen
,
696 // Insert with hint, not used when keys are unique.
697 template<typename _Arg
, typename _NodeGenerator
>
699 _M_insert(const_iterator
, _Arg
&& __arg
,
700 const _NodeGenerator
& __node_gen
, std::true_type __uk
)
703 _M_insert(std::forward
<_Arg
>(__arg
), __node_gen
, __uk
).first
;
706 // Insert with hint when keys are not unique.
707 template<typename _Arg
, typename _NodeGenerator
>
709 _M_insert(const_iterator
, _Arg
&&,
710 const _NodeGenerator
&, std::false_type
);
713 _M_erase(std::true_type
, const key_type
&);
716 _M_erase(std::false_type
, const key_type
&);
719 _M_erase(size_type __bkt
, __node_base
* __prev_n
, __node_type
* __n
);
723 template<typename
... _Args
>
725 emplace(_Args
&&... __args
)
726 { return _M_emplace(__unique_keys(), std::forward
<_Args
>(__args
)...); }
728 template<typename
... _Args
>
730 emplace_hint(const_iterator __hint
, _Args
&&... __args
)
732 return _M_emplace(__hint
, __unique_keys(),
733 std::forward
<_Args
>(__args
)...);
736 // Insert member functions via inheritance.
740 erase(const_iterator
);
745 { return erase(const_iterator(__it
)); }
748 erase(const key_type
& __k
)
749 { return _M_erase(__unique_keys(), __k
); }
752 erase(const_iterator
, const_iterator
);
757 // Set number of buckets to be appropriate for container of n element.
758 void rehash(size_type __n
);
761 // reserve, if present, comes from _Rehash_base.
764 // Helper rehash method used when keys are unique.
765 void _M_rehash_aux(size_type __n
, std::true_type
);
767 // Helper rehash method used when keys can be non-unique.
768 void _M_rehash_aux(size_type __n
, std::false_type
);
770 // Unconditionally change size of bucket array to n, restore
771 // hash policy state to __state on exception.
772 void _M_rehash(size_type __n
, const __rehash_state
& __state
);
776 // Definitions of class template _Hashtable's out-of-line member functions.
777 template<typename _Key
, typename _Value
,
778 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
779 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
782 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
783 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
784 _M_bucket_begin(size_type __bkt
) const
787 __node_base
* __n
= _M_buckets
[__bkt
];
788 return __n
? static_cast<__node_type
*>(__n
->_M_nxt
) : nullptr;
791 template<typename _Key
, typename _Value
,
792 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
793 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
795 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
796 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
797 _Hashtable(size_type __bucket_hint
,
798 const _H1
& __h1
, const _H2
& __h2
, const _Hash
& __h
,
799 const _Equal
& __eq
, const _ExtractKey
& __exk
,
800 const allocator_type
& __a
)
801 : _Hashtable(__h1
, __h2
, __h
, __eq
, __exk
, __a
)
803 auto __bkt
= _M_rehash_policy
._M_next_bkt(__bucket_hint
);
804 if (__bkt
> _M_bucket_count
)
806 _M_buckets
= _M_allocate_buckets(__bkt
);
807 _M_bucket_count
= __bkt
;
811 template<typename _Key
, typename _Value
,
812 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
813 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
815 template<typename _InputIterator
>
816 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
817 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
818 _Hashtable(_InputIterator __f
, _InputIterator __l
,
819 size_type __bucket_hint
,
820 const _H1
& __h1
, const _H2
& __h2
, const _Hash
& __h
,
821 const _Equal
& __eq
, const _ExtractKey
& __exk
,
822 const allocator_type
& __a
)
823 : _Hashtable(__h1
, __h2
, __h
, __eq
, __exk
, __a
)
825 auto __nb_elems
= __detail::__distance_fw(__f
, __l
);
827 _M_rehash_policy
._M_next_bkt(
828 std::max(_M_rehash_policy
._M_bkt_for_elements(__nb_elems
),
831 if (__bkt_count
> _M_bucket_count
)
833 _M_buckets
= _M_allocate_buckets(__bkt_count
);
834 _M_bucket_count
= __bkt_count
;
839 for (; __f
!= __l
; ++__f
)
845 _M_deallocate_buckets();
846 __throw_exception_again
;
850 template<typename _Key
, typename _Value
,
851 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
852 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
855 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
856 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
857 operator=(const _Hashtable
& __ht
)
863 if (__node_alloc_traits::_S_propagate_on_copy_assign())
865 auto& __this_alloc
= this->_M_node_allocator();
866 auto& __that_alloc
= __ht
._M_node_allocator();
867 if (!__node_alloc_traits::_S_always_equal()
868 && __this_alloc
!= __that_alloc
)
870 // Replacement allocator cannot free existing storage.
871 this->_M_deallocate_nodes(_M_begin());
872 _M_before_begin
._M_nxt
= nullptr;
873 _M_deallocate_buckets();
874 _M_buckets
= nullptr;
875 std::__alloc_on_copy(__this_alloc
, __that_alloc
);
876 __hashtable_base::operator=(__ht
);
877 _M_bucket_count
= __ht
._M_bucket_count
;
878 _M_element_count
= __ht
._M_element_count
;
879 _M_rehash_policy
= __ht
._M_rehash_policy
;
883 [this](const __node_type
* __n
)
884 { return this->_M_allocate_node(__n
->_M_v()); });
888 // _M_assign took care of deallocating all memory. Now we
889 // must make sure this instance remains in a usable state.
891 __throw_exception_again
;
895 std::__alloc_on_copy(__this_alloc
, __that_alloc
);
898 // Reuse allocated buckets and nodes.
899 __bucket_type
* __former_buckets
= nullptr;
900 std::size_t __former_bucket_count
= _M_bucket_count
;
901 const __rehash_state
& __former_state
= _M_rehash_policy
._M_state();
903 if (_M_bucket_count
!= __ht
._M_bucket_count
)
905 __former_buckets
= _M_buckets
;
906 _M_buckets
= _M_allocate_buckets(__ht
._M_bucket_count
);
907 _M_bucket_count
= __ht
._M_bucket_count
;
910 __builtin_memset(_M_buckets
, 0,
911 _M_bucket_count
* sizeof(__bucket_type
));
915 __hashtable_base::operator=(__ht
);
916 _M_element_count
= __ht
._M_element_count
;
917 _M_rehash_policy
= __ht
._M_rehash_policy
;
918 __reuse_or_alloc_node_type
__roan(_M_begin(), *this);
919 _M_before_begin
._M_nxt
= nullptr;
921 [&__roan
](const __node_type
* __n
)
922 { return __roan(__n
->_M_v()); });
923 if (__former_buckets
)
924 _M_deallocate_buckets(__former_buckets
, __former_bucket_count
);
928 if (__former_buckets
)
930 // Restore previous buckets.
931 _M_deallocate_buckets();
932 _M_rehash_policy
._M_reset(__former_state
);
933 _M_buckets
= __former_buckets
;
934 _M_bucket_count
= __former_bucket_count
;
936 __builtin_memset(_M_buckets
, 0,
937 _M_bucket_count
* sizeof(__bucket_type
));
938 __throw_exception_again
;
943 template<typename _Key
, typename _Value
,
944 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
945 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
947 template<typename _NodeGenerator
>
949 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
950 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
951 _M_assign(const _Hashtable
& __ht
, const _NodeGenerator
& __node_gen
)
953 __bucket_type
* __buckets
= nullptr;
955 _M_buckets
= __buckets
= _M_allocate_buckets(_M_bucket_count
);
959 if (!__ht
._M_before_begin
._M_nxt
)
962 // First deal with the special first node pointed to by
964 __node_type
* __ht_n
= __ht
._M_begin();
965 __node_type
* __this_n
= __node_gen(__ht_n
);
966 this->_M_copy_code(__this_n
, __ht_n
);
967 _M_before_begin
._M_nxt
= __this_n
;
968 _M_buckets
[_M_bucket_index(__this_n
)] = &_M_before_begin
;
970 // Then deal with other nodes.
971 __node_base
* __prev_n
= __this_n
;
972 for (__ht_n
= __ht_n
->_M_next(); __ht_n
; __ht_n
= __ht_n
->_M_next())
974 __this_n
= __node_gen(__ht_n
);
975 __prev_n
->_M_nxt
= __this_n
;
976 this->_M_copy_code(__this_n
, __ht_n
);
977 size_type __bkt
= _M_bucket_index(__this_n
);
978 if (!_M_buckets
[__bkt
])
979 _M_buckets
[__bkt
] = __prev_n
;
987 _M_deallocate_buckets();
988 __throw_exception_again
;
992 template<typename _Key
, typename _Value
,
993 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
994 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
997 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
998 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1001 _M_rehash_policy
._M_reset();
1002 _M_bucket_count
= 1;
1003 _M_single_bucket
= nullptr;
1004 _M_buckets
= &_M_single_bucket
;
1005 _M_before_begin
._M_nxt
= nullptr;
1006 _M_element_count
= 0;
1009 template<typename _Key
, typename _Value
,
1010 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1011 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1014 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1015 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1016 _M_move_assign(_Hashtable
&& __ht
, std::true_type
)
1018 this->_M_deallocate_nodes(_M_begin());
1019 _M_deallocate_buckets();
1020 __hashtable_base::operator=(std::move(__ht
));
1021 _M_rehash_policy
= __ht
._M_rehash_policy
;
1022 if (!__ht
._M_uses_single_bucket())
1023 _M_buckets
= __ht
._M_buckets
;
1026 _M_buckets
= &_M_single_bucket
;
1027 _M_single_bucket
= __ht
._M_single_bucket
;
1029 _M_bucket_count
= __ht
._M_bucket_count
;
1030 _M_before_begin
._M_nxt
= __ht
._M_before_begin
._M_nxt
;
1031 _M_element_count
= __ht
._M_element_count
;
1032 std::__alloc_on_move(this->_M_node_allocator(), __ht
._M_node_allocator());
1034 // Fix buckets containing the _M_before_begin pointers that can't be
1037 _M_buckets
[_M_bucket_index(_M_begin())] = &_M_before_begin
;
1041 template<typename _Key
, typename _Value
,
1042 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1043 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1046 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1047 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1048 _M_move_assign(_Hashtable
&& __ht
, std::false_type
)
1050 if (__ht
._M_node_allocator() == this->_M_node_allocator())
1051 _M_move_assign(std::move(__ht
), std::true_type());
1054 // Can't move memory, move elements then.
1055 __bucket_type
* __former_buckets
= nullptr;
1056 size_type __former_bucket_count
= _M_bucket_count
;
1057 const __rehash_state
& __former_state
= _M_rehash_policy
._M_state();
1059 if (_M_bucket_count
!= __ht
._M_bucket_count
)
1061 __former_buckets
= _M_buckets
;
1062 _M_buckets
= _M_allocate_buckets(__ht
._M_bucket_count
);
1063 _M_bucket_count
= __ht
._M_bucket_count
;
1066 __builtin_memset(_M_buckets
, 0,
1067 _M_bucket_count
* sizeof(__bucket_type
));
1071 __hashtable_base::operator=(std::move(__ht
));
1072 _M_element_count
= __ht
._M_element_count
;
1073 _M_rehash_policy
= __ht
._M_rehash_policy
;
1074 __reuse_or_alloc_node_type
__roan(_M_begin(), *this);
1075 _M_before_begin
._M_nxt
= nullptr;
1077 [&__roan
](__node_type
* __n
)
1078 { return __roan(std::move_if_noexcept(__n
->_M_v())); });
1083 if (__former_buckets
)
1085 _M_deallocate_buckets();
1086 _M_rehash_policy
._M_reset(__former_state
);
1087 _M_buckets
= __former_buckets
;
1088 _M_bucket_count
= __former_bucket_count
;
1090 __builtin_memset(_M_buckets
, 0,
1091 _M_bucket_count
* sizeof(__bucket_type
));
1092 __throw_exception_again
;
1097 template<typename _Key
, typename _Value
,
1098 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1099 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1101 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1102 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1103 _Hashtable(const _Hashtable
& __ht
)
1104 : __hashtable_base(__ht
),
1106 __rehash_base(__ht
),
1108 __node_alloc_traits::_S_select_on_copy(__ht
._M_node_allocator())),
1109 _M_buckets(nullptr),
1110 _M_bucket_count(__ht
._M_bucket_count
),
1111 _M_element_count(__ht
._M_element_count
),
1112 _M_rehash_policy(__ht
._M_rehash_policy
)
1115 [this](const __node_type
* __n
)
1116 { return this->_M_allocate_node(__n
->_M_v()); });
1119 template<typename _Key
, typename _Value
,
1120 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1121 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1123 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1124 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1125 _Hashtable(_Hashtable
&& __ht
) noexcept
1126 : __hashtable_base(__ht
),
1128 __rehash_base(__ht
),
1129 __hashtable_alloc(std::move(__ht
._M_base_alloc())),
1130 _M_buckets(__ht
._M_buckets
),
1131 _M_bucket_count(__ht
._M_bucket_count
),
1132 _M_before_begin(__ht
._M_before_begin
._M_nxt
),
1133 _M_element_count(__ht
._M_element_count
),
1134 _M_rehash_policy(__ht
._M_rehash_policy
)
1136 // Update, if necessary, buckets if __ht is using its single bucket.
1137 if (__ht
._M_uses_single_bucket())
1139 _M_buckets
= &_M_single_bucket
;
1140 _M_single_bucket
= __ht
._M_single_bucket
;
1143 // Update, if necessary, bucket pointing to before begin that hasn't
1146 _M_buckets
[_M_bucket_index(_M_begin())] = &_M_before_begin
;
1151 template<typename _Key
, typename _Value
,
1152 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1153 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1155 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1156 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1157 _Hashtable(const _Hashtable
& __ht
, const allocator_type
& __a
)
1158 : __hashtable_base(__ht
),
1160 __rehash_base(__ht
),
1161 __hashtable_alloc(__node_alloc_type(__a
)),
1163 _M_bucket_count(__ht
._M_bucket_count
),
1164 _M_element_count(__ht
._M_element_count
),
1165 _M_rehash_policy(__ht
._M_rehash_policy
)
1168 [this](const __node_type
* __n
)
1169 { return this->_M_allocate_node(__n
->_M_v()); });
1172 template<typename _Key
, typename _Value
,
1173 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1174 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1176 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1177 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1178 _Hashtable(_Hashtable
&& __ht
, const allocator_type
& __a
)
1179 : __hashtable_base(__ht
),
1181 __rehash_base(__ht
),
1182 __hashtable_alloc(__node_alloc_type(__a
)),
1183 _M_buckets(nullptr),
1184 _M_bucket_count(__ht
._M_bucket_count
),
1185 _M_element_count(__ht
._M_element_count
),
1186 _M_rehash_policy(__ht
._M_rehash_policy
)
1188 if (__ht
._M_node_allocator() == this->_M_node_allocator())
1190 if (__ht
._M_uses_single_bucket())
1192 _M_buckets
= &_M_single_bucket
;
1193 _M_single_bucket
= __ht
._M_single_bucket
;
1196 _M_buckets
= __ht
._M_buckets
;
1198 _M_before_begin
._M_nxt
= __ht
._M_before_begin
._M_nxt
;
1199 // Update, if necessary, bucket pointing to before begin that hasn't
1202 _M_buckets
[_M_bucket_index(_M_begin())] = &_M_before_begin
;
1208 [this](__node_type
* __n
)
1210 return this->_M_allocate_node(
1211 std::move_if_noexcept(__n
->_M_v()));
1217 template<typename _Key
, typename _Value
,
1218 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1219 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1221 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1222 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1223 ~_Hashtable() noexcept
1226 _M_deallocate_buckets();
1229 template<typename _Key
, typename _Value
,
1230 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1231 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1234 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1235 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1236 swap(_Hashtable
& __x
)
1237 noexcept(__node_alloc_traits::_S_nothrow_swap())
1239 // The only base class with member variables is hash_code_base.
1240 // We define _Hash_code_base::_M_swap because different
1241 // specializations have different members.
1244 std::__alloc_on_swap(this->_M_node_allocator(), __x
._M_node_allocator());
1245 std::swap(_M_rehash_policy
, __x
._M_rehash_policy
);
1247 // Deal properly with potentially moved instances.
1248 if (this->_M_uses_single_bucket())
1250 if (!__x
._M_uses_single_bucket())
1252 _M_buckets
= __x
._M_buckets
;
1253 __x
._M_buckets
= &__x
._M_single_bucket
;
1256 else if (__x
._M_uses_single_bucket())
1258 __x
._M_buckets
= _M_buckets
;
1259 _M_buckets
= &_M_single_bucket
;
1262 std::swap(_M_buckets
, __x
._M_buckets
);
1264 std::swap(_M_bucket_count
, __x
._M_bucket_count
);
1265 std::swap(_M_before_begin
._M_nxt
, __x
._M_before_begin
._M_nxt
);
1266 std::swap(_M_element_count
, __x
._M_element_count
);
1267 std::swap(_M_single_bucket
, __x
._M_single_bucket
);
1269 // Fix buckets containing the _M_before_begin pointers that can't be
1272 _M_buckets
[_M_bucket_index(_M_begin())] = &_M_before_begin
;
1275 __x
._M_buckets
[__x
._M_bucket_index(__x
._M_begin())]
1276 = &__x
._M_before_begin
;
1279 template<typename _Key
, typename _Value
,
1280 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1281 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1284 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1285 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1286 __rehash_policy(const _RehashPolicy
& __pol
)
1289 __pol
._M_need_rehash(_M_bucket_count
, _M_element_count
, 0);
1290 if (__do_rehash
.first
)
1291 _M_rehash(__do_rehash
.second
, _M_rehash_policy
._M_state());
1292 _M_rehash_policy
= __pol
;
1295 template<typename _Key
, typename _Value
,
1296 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1297 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1300 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1301 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1302 find(const key_type
& __k
)
1305 __hash_code __code
= this->_M_hash_code(__k
);
1306 std::size_t __n
= _M_bucket_index(__k
, __code
);
1307 __node_type
* __p
= _M_find_node(__n
, __k
, __code
);
1308 return __p
? iterator(__p
) : end();
1311 template<typename _Key
, typename _Value
,
1312 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1313 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1316 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1317 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1318 find(const key_type
& __k
) const
1321 __hash_code __code
= this->_M_hash_code(__k
);
1322 std::size_t __n
= _M_bucket_index(__k
, __code
);
1323 __node_type
* __p
= _M_find_node(__n
, __k
, __code
);
1324 return __p
? const_iterator(__p
) : end();
1327 template<typename _Key
, typename _Value
,
1328 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1329 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1332 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1333 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1334 count(const key_type
& __k
) const
1337 __hash_code __code
= this->_M_hash_code(__k
);
1338 std::size_t __n
= _M_bucket_index(__k
, __code
);
1339 __node_type
* __p
= _M_bucket_begin(__n
);
1343 std::size_t __result
= 0;
1344 for (;; __p
= __p
->_M_next())
1346 if (this->_M_equals(__k
, __code
, __p
))
1349 // All equivalent values are next to each other, if we
1350 // found a non-equivalent value after an equivalent one it
1351 // means that we won't find any new equivalent value.
1353 if (!__p
->_M_nxt
|| _M_bucket_index(__p
->_M_next()) != __n
)
1359 template<typename _Key
, typename _Value
,
1360 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1361 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1364 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1365 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1366 equal_range(const key_type
& __k
)
1367 -> pair
<iterator
, iterator
>
1369 __hash_code __code
= this->_M_hash_code(__k
);
1370 std::size_t __n
= _M_bucket_index(__k
, __code
);
1371 __node_type
* __p
= _M_find_node(__n
, __k
, __code
);
1375 __node_type
* __p1
= __p
->_M_next();
1376 while (__p1
&& _M_bucket_index(__p1
) == __n
1377 && this->_M_equals(__k
, __code
, __p1
))
1378 __p1
= __p1
->_M_next();
1380 return std::make_pair(iterator(__p
), iterator(__p1
));
1383 return std::make_pair(end(), end());
1386 template<typename _Key
, typename _Value
,
1387 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1388 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1391 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1392 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1393 equal_range(const key_type
& __k
) const
1394 -> pair
<const_iterator
, const_iterator
>
1396 __hash_code __code
= this->_M_hash_code(__k
);
1397 std::size_t __n
= _M_bucket_index(__k
, __code
);
1398 __node_type
* __p
= _M_find_node(__n
, __k
, __code
);
1402 __node_type
* __p1
= __p
->_M_next();
1403 while (__p1
&& _M_bucket_index(__p1
) == __n
1404 && this->_M_equals(__k
, __code
, __p1
))
1405 __p1
= __p1
->_M_next();
1407 return std::make_pair(const_iterator(__p
), const_iterator(__p1
));
1410 return std::make_pair(end(), end());
1413 // Find the node whose key compares equal to k in the bucket n.
1414 // Return nullptr if no node is found.
1415 template<typename _Key
, typename _Value
,
1416 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1417 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1420 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1421 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1422 _M_find_before_node(size_type __n
, const key_type
& __k
,
1423 __hash_code __code
) const
1426 __node_base
* __prev_p
= _M_buckets
[__n
];
1430 for (__node_type
* __p
= static_cast<__node_type
*>(__prev_p
->_M_nxt
);;
1431 __p
= __p
->_M_next())
1433 if (this->_M_equals(__k
, __code
, __p
))
1436 if (!__p
->_M_nxt
|| _M_bucket_index(__p
->_M_next()) != __n
)
1443 template<typename _Key
, typename _Value
,
1444 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1445 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1448 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1449 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1450 _M_insert_bucket_begin(size_type __bkt
, __node_type
* __node
)
1452 if (_M_buckets
[__bkt
])
1454 // Bucket is not empty, we just need to insert the new node
1455 // after the bucket before begin.
1456 __node
->_M_nxt
= _M_buckets
[__bkt
]->_M_nxt
;
1457 _M_buckets
[__bkt
]->_M_nxt
= __node
;
1461 // The bucket is empty, the new node is inserted at the
1462 // beginning of the singly-linked list and the bucket will
1463 // contain _M_before_begin pointer.
1464 __node
->_M_nxt
= _M_before_begin
._M_nxt
;
1465 _M_before_begin
._M_nxt
= __node
;
1467 // We must update former begin bucket that is pointing to
1469 _M_buckets
[_M_bucket_index(__node
->_M_next())] = __node
;
1470 _M_buckets
[__bkt
] = &_M_before_begin
;
1474 template<typename _Key
, typename _Value
,
1475 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1476 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1479 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1480 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1481 _M_remove_bucket_begin(size_type __bkt
, __node_type
* __next
,
1482 size_type __next_bkt
)
1484 if (!__next
|| __next_bkt
!= __bkt
)
1486 // Bucket is now empty
1487 // First update next bucket if any
1489 _M_buckets
[__next_bkt
] = _M_buckets
[__bkt
];
1491 // Second update before begin node if necessary
1492 if (&_M_before_begin
== _M_buckets
[__bkt
])
1493 _M_before_begin
._M_nxt
= __next
;
1494 _M_buckets
[__bkt
] = nullptr;
1498 template<typename _Key
, typename _Value
,
1499 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1500 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1503 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1504 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1505 _M_get_previous_node(size_type __bkt
, __node_base
* __n
)
1508 __node_base
* __prev_n
= _M_buckets
[__bkt
];
1509 while (__prev_n
->_M_nxt
!= __n
)
1510 __prev_n
= __prev_n
->_M_nxt
;
1514 template<typename _Key
, typename _Value
,
1515 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1516 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1518 template<typename
... _Args
>
1520 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1521 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1522 _M_emplace(std::true_type
, _Args
&&... __args
)
1523 -> pair
<iterator
, bool>
1525 // First build the node to get access to the hash code
1526 __node_type
* __node
= this->_M_allocate_node(std::forward
<_Args
>(__args
)...);
1527 const key_type
& __k
= this->_M_extract()(__node
->_M_v());
1531 __code
= this->_M_hash_code(__k
);
1535 this->_M_deallocate_node(__node
);
1536 __throw_exception_again
;
1539 size_type __bkt
= _M_bucket_index(__k
, __code
);
1540 if (__node_type
* __p
= _M_find_node(__bkt
, __k
, __code
))
1542 // There is already an equivalent node, no insertion
1543 this->_M_deallocate_node(__node
);
1544 return std::make_pair(iterator(__p
), false);
1548 return std::make_pair(_M_insert_unique_node(__bkt
, __code
, __node
),
1552 template<typename _Key
, typename _Value
,
1553 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1554 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1556 template<typename
... _Args
>
1558 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1559 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1560 _M_emplace(const_iterator __hint
, std::false_type
, _Args
&&... __args
)
1563 // First build the node to get its hash code.
1564 __node_type
* __node
=
1565 this->_M_allocate_node(std::forward
<_Args
>(__args
)...);
1570 __code
= this->_M_hash_code(this->_M_extract()(__node
->_M_v()));
1574 this->_M_deallocate_node(__node
);
1575 __throw_exception_again
;
1578 return _M_insert_multi_node(__hint
._M_cur
, __code
, __node
);
1581 template<typename _Key
, typename _Value
,
1582 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1583 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1586 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1587 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1588 _M_insert_unique_node(size_type __bkt
, __hash_code __code
,
1589 __node_type
* __node
)
1592 const __rehash_state
& __saved_state
= _M_rehash_policy
._M_state();
1593 std::pair
<bool, std::size_t> __do_rehash
1594 = _M_rehash_policy
._M_need_rehash(_M_bucket_count
, _M_element_count
, 1);
1598 if (__do_rehash
.first
)
1600 _M_rehash(__do_rehash
.second
, __saved_state
);
1601 __bkt
= _M_bucket_index(this->_M_extract()(__node
->_M_v()), __code
);
1604 this->_M_store_code(__node
, __code
);
1606 // Always insert at the beginning of the bucket.
1607 _M_insert_bucket_begin(__bkt
, __node
);
1609 return iterator(__node
);
1613 this->_M_deallocate_node(__node
);
1614 __throw_exception_again
;
1618 // Insert node, in bucket bkt if no rehash (assumes no element with its key
1619 // already present). Take ownership of the node, deallocate it on exception.
1620 template<typename _Key
, typename _Value
,
1621 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1622 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1625 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1626 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1627 _M_insert_multi_node(__node_type
* __hint
, __hash_code __code
,
1628 __node_type
* __node
)
1631 const __rehash_state
& __saved_state
= _M_rehash_policy
._M_state();
1632 std::pair
<bool, std::size_t> __do_rehash
1633 = _M_rehash_policy
._M_need_rehash(_M_bucket_count
, _M_element_count
, 1);
1637 if (__do_rehash
.first
)
1638 _M_rehash(__do_rehash
.second
, __saved_state
);
1640 this->_M_store_code(__node
, __code
);
1641 const key_type
& __k
= this->_M_extract()(__node
->_M_v());
1642 size_type __bkt
= _M_bucket_index(__k
, __code
);
1644 // Find the node before an equivalent one or use hint if it exists and
1645 // if it is equivalent.
1647 = __builtin_expect(__hint
!= nullptr, false)
1648 && this->_M_equals(__k
, __code
, __hint
)
1650 : _M_find_before_node(__bkt
, __k
, __code
);
1653 // Insert after the node before the equivalent one.
1654 __node
->_M_nxt
= __prev
->_M_nxt
;
1655 __prev
->_M_nxt
= __node
;
1656 if (__builtin_expect(__prev
== __hint
, false))
1657 // hint might be the last bucket node, in this case we need to
1658 // update next bucket.
1660 && !this->_M_equals(__k
, __code
, __node
->_M_next()))
1662 size_type __next_bkt
= _M_bucket_index(__node
->_M_next());
1663 if (__next_bkt
!= __bkt
)
1664 _M_buckets
[__next_bkt
] = __node
;
1668 // The inserted node has no equivalent in the
1669 // hashtable. We must insert the new node at the
1670 // beginning of the bucket to preserve equivalent
1671 // elements' relative positions.
1672 _M_insert_bucket_begin(__bkt
, __node
);
1674 return iterator(__node
);
1678 this->_M_deallocate_node(__node
);
1679 __throw_exception_again
;
1683 // Insert v if no element with its key is already present.
1684 template<typename _Key
, typename _Value
,
1685 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1686 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1688 template<typename _Arg
, typename _NodeGenerator
>
1690 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1691 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1692 _M_insert(_Arg
&& __v
, const _NodeGenerator
& __node_gen
, std::true_type
)
1693 -> pair
<iterator
, bool>
1695 const key_type
& __k
= this->_M_extract()(__v
);
1696 __hash_code __code
= this->_M_hash_code(__k
);
1697 size_type __bkt
= _M_bucket_index(__k
, __code
);
1699 __node_type
* __n
= _M_find_node(__bkt
, __k
, __code
);
1701 return std::make_pair(iterator(__n
), false);
1703 __n
= __node_gen(std::forward
<_Arg
>(__v
));
1704 return std::make_pair(_M_insert_unique_node(__bkt
, __code
, __n
), true);
1707 // Insert v unconditionally.
1708 template<typename _Key
, typename _Value
,
1709 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1710 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1712 template<typename _Arg
, typename _NodeGenerator
>
1714 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1715 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1716 _M_insert(const_iterator __hint
, _Arg
&& __v
,
1717 const _NodeGenerator
& __node_gen
, std::false_type
)
1720 // First compute the hash code so that we don't do anything if it
1722 __hash_code __code
= this->_M_hash_code(this->_M_extract()(__v
));
1724 // Second allocate new node so that we don't rehash if it throws.
1725 __node_type
* __node
= __node_gen(std::forward
<_Arg
>(__v
));
1727 return _M_insert_multi_node(__hint
._M_cur
, __code
, __node
);
1730 template<typename _Key
, typename _Value
,
1731 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1732 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1735 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1736 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1737 erase(const_iterator __it
)
1740 __node_type
* __n
= __it
._M_cur
;
1741 std::size_t __bkt
= _M_bucket_index(__n
);
1743 // Look for previous node to unlink it from the erased one, this
1744 // is why we need buckets to contain the before begin to make
1745 // this search fast.
1746 __node_base
* __prev_n
= _M_get_previous_node(__bkt
, __n
);
1747 return _M_erase(__bkt
, __prev_n
, __n
);
1750 template<typename _Key
, typename _Value
,
1751 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1752 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1755 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1756 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1757 _M_erase(size_type __bkt
, __node_base
* __prev_n
, __node_type
* __n
)
1760 if (__prev_n
== _M_buckets
[__bkt
])
1761 _M_remove_bucket_begin(__bkt
, __n
->_M_next(),
1762 __n
->_M_nxt
? _M_bucket_index(__n
->_M_next()) : 0);
1763 else if (__n
->_M_nxt
)
1765 size_type __next_bkt
= _M_bucket_index(__n
->_M_next());
1766 if (__next_bkt
!= __bkt
)
1767 _M_buckets
[__next_bkt
] = __prev_n
;
1770 __prev_n
->_M_nxt
= __n
->_M_nxt
;
1771 iterator
__result(__n
->_M_next());
1772 this->_M_deallocate_node(__n
);
1778 template<typename _Key
, typename _Value
,
1779 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1780 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1783 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1784 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1785 _M_erase(std::true_type
, const key_type
& __k
)
1788 __hash_code __code
= this->_M_hash_code(__k
);
1789 std::size_t __bkt
= _M_bucket_index(__k
, __code
);
1791 // Look for the node before the first matching node.
1792 __node_base
* __prev_n
= _M_find_before_node(__bkt
, __k
, __code
);
1796 // We found a matching node, erase it.
1797 __node_type
* __n
= static_cast<__node_type
*>(__prev_n
->_M_nxt
);
1798 _M_erase(__bkt
, __prev_n
, __n
);
1802 template<typename _Key
, typename _Value
,
1803 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1804 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1807 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1808 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1809 _M_erase(std::false_type
, const key_type
& __k
)
1812 __hash_code __code
= this->_M_hash_code(__k
);
1813 std::size_t __bkt
= _M_bucket_index(__k
, __code
);
1815 // Look for the node before the first matching node.
1816 __node_base
* __prev_n
= _M_find_before_node(__bkt
, __k
, __code
);
1820 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1821 // 526. Is it undefined if a function in the standard changes
1823 // We use one loop to find all matching nodes and another to deallocate
1824 // them so that the key stays valid during the first loop. It might be
1825 // invalidated indirectly when destroying nodes.
1826 __node_type
* __n
= static_cast<__node_type
*>(__prev_n
->_M_nxt
);
1827 __node_type
* __n_last
= __n
;
1828 std::size_t __n_last_bkt
= __bkt
;
1831 __n_last
= __n_last
->_M_next();
1834 __n_last_bkt
= _M_bucket_index(__n_last
);
1836 while (__n_last_bkt
== __bkt
&& this->_M_equals(__k
, __code
, __n_last
));
1838 // Deallocate nodes.
1839 size_type __result
= 0;
1842 __node_type
* __p
= __n
->_M_next();
1843 this->_M_deallocate_node(__n
);
1848 while (__n
!= __n_last
);
1850 if (__prev_n
== _M_buckets
[__bkt
])
1851 _M_remove_bucket_begin(__bkt
, __n_last
, __n_last_bkt
);
1852 else if (__n_last
&& __n_last_bkt
!= __bkt
)
1853 _M_buckets
[__n_last_bkt
] = __prev_n
;
1854 __prev_n
->_M_nxt
= __n_last
;
1858 template<typename _Key
, typename _Value
,
1859 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1860 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1863 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1864 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1865 erase(const_iterator __first
, const_iterator __last
)
1868 __node_type
* __n
= __first
._M_cur
;
1869 __node_type
* __last_n
= __last
._M_cur
;
1870 if (__n
== __last_n
)
1871 return iterator(__n
);
1873 std::size_t __bkt
= _M_bucket_index(__n
);
1875 __node_base
* __prev_n
= _M_get_previous_node(__bkt
, __n
);
1876 bool __is_bucket_begin
= __n
== _M_bucket_begin(__bkt
);
1877 std::size_t __n_bkt
= __bkt
;
1882 __node_type
* __tmp
= __n
;
1883 __n
= __n
->_M_next();
1884 this->_M_deallocate_node(__tmp
);
1888 __n_bkt
= _M_bucket_index(__n
);
1890 while (__n
!= __last_n
&& __n_bkt
== __bkt
);
1891 if (__is_bucket_begin
)
1892 _M_remove_bucket_begin(__bkt
, __n
, __n_bkt
);
1893 if (__n
== __last_n
)
1895 __is_bucket_begin
= true;
1899 if (__n
&& (__n_bkt
!= __bkt
|| __is_bucket_begin
))
1900 _M_buckets
[__n_bkt
] = __prev_n
;
1901 __prev_n
->_M_nxt
= __n
;
1902 return iterator(__n
);
1905 template<typename _Key
, typename _Value
,
1906 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1907 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1910 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1911 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1914 this->_M_deallocate_nodes(_M_begin());
1915 __builtin_memset(_M_buckets
, 0, _M_bucket_count
* sizeof(__bucket_type
));
1916 _M_element_count
= 0;
1917 _M_before_begin
._M_nxt
= nullptr;
1920 template<typename _Key
, typename _Value
,
1921 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1922 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1925 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1926 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1927 rehash(size_type __n
)
1929 const __rehash_state
& __saved_state
= _M_rehash_policy
._M_state();
1930 std::size_t __buckets
1931 = std::max(_M_rehash_policy
._M_bkt_for_elements(_M_element_count
+ 1),
1933 __buckets
= _M_rehash_policy
._M_next_bkt(__buckets
);
1935 if (__buckets
!= _M_bucket_count
)
1936 _M_rehash(__buckets
, __saved_state
);
1938 // No rehash, restore previous state to keep a consistent state.
1939 _M_rehash_policy
._M_reset(__saved_state
);
1942 template<typename _Key
, typename _Value
,
1943 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1944 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1947 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1948 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1949 _M_rehash(size_type __n
, const __rehash_state
& __state
)
1953 _M_rehash_aux(__n
, __unique_keys());
1957 // A failure here means that buckets allocation failed. We only
1958 // have to restore hash policy previous state.
1959 _M_rehash_policy
._M_reset(__state
);
1960 __throw_exception_again
;
1964 // Rehash when there is no equivalent elements.
1965 template<typename _Key
, typename _Value
,
1966 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1967 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1970 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1971 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1972 _M_rehash_aux(size_type __n
, std::true_type
)
1974 __bucket_type
* __new_buckets
= _M_allocate_buckets(__n
);
1975 __node_type
* __p
= _M_begin();
1976 _M_before_begin
._M_nxt
= nullptr;
1977 std::size_t __bbegin_bkt
= 0;
1980 __node_type
* __next
= __p
->_M_next();
1981 std::size_t __bkt
= __hash_code_base::_M_bucket_index(__p
, __n
);
1982 if (!__new_buckets
[__bkt
])
1984 __p
->_M_nxt
= _M_before_begin
._M_nxt
;
1985 _M_before_begin
._M_nxt
= __p
;
1986 __new_buckets
[__bkt
] = &_M_before_begin
;
1988 __new_buckets
[__bbegin_bkt
] = __p
;
1989 __bbegin_bkt
= __bkt
;
1993 __p
->_M_nxt
= __new_buckets
[__bkt
]->_M_nxt
;
1994 __new_buckets
[__bkt
]->_M_nxt
= __p
;
1999 _M_deallocate_buckets();
2000 _M_bucket_count
= __n
;
2001 _M_buckets
= __new_buckets
;
2004 // Rehash when there can be equivalent elements, preserve their relative
2006 template<typename _Key
, typename _Value
,
2007 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
2008 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
2011 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
2012 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
2013 _M_rehash_aux(size_type __n
, std::false_type
)
2015 __bucket_type
* __new_buckets
= _M_allocate_buckets(__n
);
2017 __node_type
* __p
= _M_begin();
2018 _M_before_begin
._M_nxt
= nullptr;
2019 std::size_t __bbegin_bkt
= 0;
2020 std::size_t __prev_bkt
= 0;
2021 __node_type
* __prev_p
= nullptr;
2022 bool __check_bucket
= false;
2026 __node_type
* __next
= __p
->_M_next();
2027 std::size_t __bkt
= __hash_code_base::_M_bucket_index(__p
, __n
);
2029 if (__prev_p
&& __prev_bkt
== __bkt
)
2031 // Previous insert was already in this bucket, we insert after
2032 // the previously inserted one to preserve equivalent elements
2034 __p
->_M_nxt
= __prev_p
->_M_nxt
;
2035 __prev_p
->_M_nxt
= __p
;
2037 // Inserting after a node in a bucket require to check that we
2038 // haven't change the bucket last node, in this case next
2039 // bucket containing its before begin node must be updated. We
2040 // schedule a check as soon as we move out of the sequence of
2041 // equivalent nodes to limit the number of checks.
2042 __check_bucket
= true;
2048 // Check if we shall update the next bucket because of
2049 // insertions into __prev_bkt bucket.
2050 if (__prev_p
->_M_nxt
)
2052 std::size_t __next_bkt
2053 = __hash_code_base::_M_bucket_index(__prev_p
->_M_next(),
2055 if (__next_bkt
!= __prev_bkt
)
2056 __new_buckets
[__next_bkt
] = __prev_p
;
2058 __check_bucket
= false;
2061 if (!__new_buckets
[__bkt
])
2063 __p
->_M_nxt
= _M_before_begin
._M_nxt
;
2064 _M_before_begin
._M_nxt
= __p
;
2065 __new_buckets
[__bkt
] = &_M_before_begin
;
2067 __new_buckets
[__bbegin_bkt
] = __p
;
2068 __bbegin_bkt
= __bkt
;
2072 __p
->_M_nxt
= __new_buckets
[__bkt
]->_M_nxt
;
2073 __new_buckets
[__bkt
]->_M_nxt
= __p
;
2081 if (__check_bucket
&& __prev_p
->_M_nxt
)
2083 std::size_t __next_bkt
2084 = __hash_code_base::_M_bucket_index(__prev_p
->_M_next(), __n
);
2085 if (__next_bkt
!= __prev_bkt
)
2086 __new_buckets
[__next_bkt
] = __prev_p
;
2089 _M_deallocate_buckets();
2090 _M_bucket_count
= __n
;
2091 _M_buckets
= __new_buckets
;
2094 _GLIBCXX_END_NAMESPACE_VERSION
2097 #endif // _HASHTABLE_H