1 // hashtable.h header -*- C++ -*-
3 // Copyright (C) 2007-2016 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>
36 #if __cplusplus > 201402L
37 # include <bits/node_handle.h>
40 namespace std
_GLIBCXX_VISIBILITY(default)
42 _GLIBCXX_BEGIN_NAMESPACE_VERSION
44 template<typename _Tp
, typename _Hash
>
46 = __not_
<__and_
<// Do not cache for fast hasher.
47 __is_fast_hash
<_Hash
>,
48 // Mandatory to have erase not throwing.
49 __detail::__is_noexcept_hash
<_Tp
, _Hash
>>>;
52 * Primary class template _Hashtable.
54 * @ingroup hashtable-detail
56 * @tparam _Value CopyConstructible type.
58 * @tparam _Key CopyConstructible type.
60 * @tparam _Alloc An allocator type
61 * ([lib.allocator.requirements]) whose _Alloc::value_type is
62 * _Value. As a conforming extension, we allow for
63 * _Alloc::value_type != _Value.
65 * @tparam _ExtractKey Function object that takes an object of type
66 * _Value and returns a value of type _Key.
68 * @tparam _Equal Function object that takes two objects of type k
69 * and returns a bool-like value that is true if the two objects
70 * are considered equal.
72 * @tparam _H1 The hash function. A unary function object with
73 * argument type _Key and result type size_t. Return values should
74 * be distributed over the entire range [0, numeric_limits<size_t>:::max()].
76 * @tparam _H2 The range-hashing function (in the terminology of
77 * Tavori and Dreizin). A binary function object whose argument
78 * types and result type are all size_t. Given arguments r and N,
79 * the return value is in the range [0, N).
81 * @tparam _Hash The ranged hash function (Tavori and Dreizin). A
82 * binary function whose argument types are _Key and size_t and
83 * whose result type is size_t. Given arguments k and N, the
84 * return value is in the range [0, N). Default: hash(k, N) =
85 * h2(h1(k), N). If _Hash is anything other than the default, _H1
86 * and _H2 are ignored.
88 * @tparam _RehashPolicy Policy class with three members, all of
89 * which govern the bucket count. _M_next_bkt(n) returns a bucket
90 * count no smaller than n. _M_bkt_for_elements(n) returns a
91 * bucket count appropriate for an element count of n.
92 * _M_need_rehash(n_bkt, n_elt, n_ins) determines whether, if the
93 * current bucket count is n_bkt and the current element count is
94 * n_elt, we need to increase the bucket count. If so, returns
95 * make_pair(true, n), where n is the new bucket count. If not,
96 * returns make_pair(false, <anything>)
98 * @tparam _Traits Compile-time class with three boolean
99 * std::integral_constant members: __cache_hash_code, __constant_iterators,
102 * Each _Hashtable data structure has:
104 * - _Bucket[] _M_buckets
105 * - _Hash_node_base _M_before_begin
106 * - size_type _M_bucket_count
107 * - size_type _M_element_count
109 * with _Bucket being _Hash_node* and _Hash_node containing:
111 * - _Hash_node* _M_next
113 * - size_t _M_hash_code if cache_hash_code is true
115 * In terms of Standard containers the hashtable is like the aggregation of:
117 * - std::forward_list<_Node> containing the elements
118 * - std::vector<std::forward_list<_Node>::iterator> representing the buckets
120 * The non-empty buckets contain the node before the first node in the
121 * bucket. This design makes it possible to implement something like a
122 * std::forward_list::insert_after on container insertion and
123 * std::forward_list::erase_after on container erase
124 * calls. _M_before_begin is equivalent to
125 * std::forward_list::before_begin. Empty buckets contain
126 * nullptr. Note that one of the non-empty buckets contains
127 * &_M_before_begin which is not a dereferenceable node so the
128 * node pointer in a bucket shall never be dereferenced, only its
131 * Walking through a bucket's nodes requires a check on the hash code to
132 * see if each node is still in the bucket. Such a design assumes a
133 * quite efficient hash functor and is one of the reasons it is
134 * highly advisable to set __cache_hash_code to true.
136 * The container iterators are simply built from nodes. This way
137 * incrementing the iterator is perfectly efficient independent of
138 * how many empty buckets there are in the container.
140 * On insert we compute the element's hash code and use it to find the
141 * bucket index. If the element must be inserted in an empty bucket
142 * we add it at the beginning of the singly linked list and make the
143 * bucket point to _M_before_begin. The bucket that used to point to
144 * _M_before_begin, if any, is updated to point to its new before
147 * On erase, the simple iterator design requires using the hash
148 * functor to get the index of the bucket to update. For this
149 * reason, when __cache_hash_code is set to false the hash functor must
150 * not throw and this is enforced by a static assertion.
152 * Functionality is implemented by decomposition into base classes,
153 * where the derived _Hashtable class is used in _Map_base,
154 * _Insert, _Rehash_base, and _Equality base classes to access the
155 * "this" pointer. _Hashtable_base is used in the base classes as a
156 * non-recursive, fully-completed-type so that detailed nested type
157 * information, such as iterator type and node type, can be
158 * used. This is similar to the "Curiously Recurring Template
159 * Pattern" (CRTP) technique, but uses a reconstructed, not
160 * explicitly passed, template pattern.
162 * Base class templates are:
163 * - __detail::_Hashtable_base
164 * - __detail::_Map_base
165 * - __detail::_Insert
166 * - __detail::_Rehash_base
167 * - __detail::_Equality
169 template<typename _Key
, typename _Value
, typename _Alloc
,
170 typename _ExtractKey
, typename _Equal
,
171 typename _H1
, typename _H2
, typename _Hash
,
172 typename _RehashPolicy
, typename _Traits
>
174 : public __detail::_Hashtable_base
<_Key
, _Value
, _ExtractKey
, _Equal
,
175 _H1
, _H2
, _Hash
, _Traits
>,
176 public __detail::_Map_base
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
177 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>,
178 public __detail::_Insert
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
179 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>,
180 public __detail::_Rehash_base
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
181 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>,
182 public __detail::_Equality
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
183 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>,
184 private __detail::_Hashtable_alloc
<
185 __alloc_rebind
<_Alloc
,
186 __detail::_Hash_node
<_Value
,
187 _Traits::__hash_cached::value
>>>
189 using __traits_type
= _Traits
;
190 using __hash_cached
= typename
__traits_type::__hash_cached
;
191 using __node_type
= __detail::_Hash_node
<_Value
, __hash_cached::value
>;
192 using __node_alloc_type
= __alloc_rebind
<_Alloc
, __node_type
>;
194 using __hashtable_alloc
= __detail::_Hashtable_alloc
<__node_alloc_type
>;
196 using __value_alloc_traits
=
197 typename
__hashtable_alloc::__value_alloc_traits
;
198 using __node_alloc_traits
=
199 typename
__hashtable_alloc::__node_alloc_traits
;
200 using __node_base
= typename
__hashtable_alloc::__node_base
;
201 using __bucket_type
= typename
__hashtable_alloc::__bucket_type
;
204 typedef _Key key_type
;
205 typedef _Value value_type
;
206 typedef _Alloc allocator_type
;
207 typedef _Equal key_equal
;
209 // mapped_type, if present, comes from _Map_base.
210 // hasher, if present, comes from _Hash_code_base/_Hashtable_base.
211 typedef typename
__value_alloc_traits::pointer pointer
;
212 typedef typename
__value_alloc_traits::const_pointer const_pointer
;
213 typedef value_type
& reference
;
214 typedef const value_type
& const_reference
;
217 using __rehash_type
= _RehashPolicy
;
218 using __rehash_state
= typename
__rehash_type::_State
;
220 using __constant_iterators
= typename
__traits_type::__constant_iterators
;
221 using __unique_keys
= typename
__traits_type::__unique_keys
;
223 using __key_extract
= typename
std::conditional
<
224 __constant_iterators::value
,
226 __detail::_Select1st
>::type
;
228 using __hashtable_base
= __detail::
229 _Hashtable_base
<_Key
, _Value
, _ExtractKey
,
230 _Equal
, _H1
, _H2
, _Hash
, _Traits
>;
232 using __hash_code_base
= typename
__hashtable_base::__hash_code_base
;
233 using __hash_code
= typename
__hashtable_base::__hash_code
;
234 using __ireturn_type
= typename
__hashtable_base::__ireturn_type
;
236 using __map_base
= __detail::_Map_base
<_Key
, _Value
, _Alloc
, _ExtractKey
,
237 _Equal
, _H1
, _H2
, _Hash
,
238 _RehashPolicy
, _Traits
>;
240 using __rehash_base
= __detail::_Rehash_base
<_Key
, _Value
, _Alloc
,
243 _RehashPolicy
, _Traits
>;
245 using __eq_base
= __detail::_Equality
<_Key
, _Value
, _Alloc
, _ExtractKey
,
246 _Equal
, _H1
, _H2
, _Hash
,
247 _RehashPolicy
, _Traits
>;
249 using __reuse_or_alloc_node_type
=
250 __detail::_ReuseOrAllocNode
<__node_alloc_type
>;
252 // Metaprogramming for picking apart hash caching.
253 template<typename _Cond
>
254 using __if_hash_cached
= __or_
<__not_
<__hash_cached
>, _Cond
>;
256 template<typename _Cond
>
257 using __if_hash_not_cached
= __or_
<__hash_cached
, _Cond
>;
259 // Compile-time diagnostics.
261 // _Hash_code_base has everything protected, so use this derived type to
263 struct __hash_code_base_access
: __hash_code_base
264 { using __hash_code_base::_M_bucket_index
; };
266 // Getting a bucket index from a node shall not throw because it is used
267 // in methods (erase, swap...) that shall not throw.
268 static_assert(noexcept(declval
<const __hash_code_base_access
&>()
269 ._M_bucket_index((const __node_type
*)nullptr,
271 "Cache the hash code or qualify your functors involved"
272 " in hash code and bucket index computation with noexcept");
274 // Following two static assertions are necessary to guarantee
275 // that local_iterator will be default constructible.
277 // When hash codes are cached local iterator inherits from H2 functor
278 // which must then be default constructible.
279 static_assert(__if_hash_cached
<is_default_constructible
<_H2
>>::value
,
280 "Functor used to map hash code to bucket index"
281 " must be default constructible");
283 template<typename _Keya
, typename _Valuea
, typename _Alloca
,
284 typename _ExtractKeya
, typename _Equala
,
285 typename _H1a
, typename _H2a
, typename _Hasha
,
286 typename _RehashPolicya
, typename _Traitsa
,
288 friend struct __detail::_Map_base
;
290 template<typename _Keya
, typename _Valuea
, typename _Alloca
,
291 typename _ExtractKeya
, typename _Equala
,
292 typename _H1a
, typename _H2a
, typename _Hasha
,
293 typename _RehashPolicya
, typename _Traitsa
>
294 friend struct __detail::_Insert_base
;
296 template<typename _Keya
, typename _Valuea
, typename _Alloca
,
297 typename _ExtractKeya
, typename _Equala
,
298 typename _H1a
, typename _H2a
, typename _Hasha
,
299 typename _RehashPolicya
, typename _Traitsa
,
300 bool _Constant_iteratorsa
>
301 friend struct __detail::_Insert
;
304 using size_type
= typename
__hashtable_base::size_type
;
305 using difference_type
= typename
__hashtable_base::difference_type
;
307 using iterator
= typename
__hashtable_base::iterator
;
308 using const_iterator
= typename
__hashtable_base::const_iterator
;
310 using local_iterator
= typename
__hashtable_base::local_iterator
;
311 using const_local_iterator
= typename
__hashtable_base::
312 const_local_iterator
;
314 #if __cplusplus > 201402L
315 using node_type
= _Node_handle
<_Key
, _Value
, __node_alloc_type
>;
316 using insert_return_type
= _Node_insert_return
<iterator
, node_type
>;
320 __bucket_type
* _M_buckets
= &_M_single_bucket
;
321 size_type _M_bucket_count
= 1;
322 __node_base _M_before_begin
;
323 size_type _M_element_count
= 0;
324 _RehashPolicy _M_rehash_policy
;
326 // A single bucket used when only need for 1 bucket. Especially
327 // interesting in move semantic to leave hashtable with only 1 buckets
328 // which is not allocated so that we can have those operations noexcept
330 // Note that we can't leave hashtable with 0 bucket without adding
331 // numerous checks in the code to avoid 0 modulus.
332 __bucket_type _M_single_bucket
= nullptr;
335 _M_uses_single_bucket(__bucket_type
* __bkts
) const
336 { return __builtin_expect(__bkts
== &_M_single_bucket
, false); }
339 _M_uses_single_bucket() const
340 { return _M_uses_single_bucket(_M_buckets
); }
343 _M_base_alloc() { return *this; }
346 _M_allocate_buckets(size_type __n
)
348 if (__builtin_expect(__n
== 1, false))
350 _M_single_bucket
= nullptr;
351 return &_M_single_bucket
;
354 return __hashtable_alloc::_M_allocate_buckets(__n
);
358 _M_deallocate_buckets(__bucket_type
* __bkts
, size_type __n
)
360 if (_M_uses_single_bucket(__bkts
))
363 __hashtable_alloc::_M_deallocate_buckets(__bkts
, __n
);
367 _M_deallocate_buckets()
368 { _M_deallocate_buckets(_M_buckets
, _M_bucket_count
); }
370 // Gets bucket begin, deals with the fact that non-empty buckets contain
371 // their before begin node.
373 _M_bucket_begin(size_type __bkt
) const;
377 { return static_cast<__node_type
*>(_M_before_begin
._M_nxt
); }
379 template<typename _NodeGenerator
>
381 _M_assign(const _Hashtable
&, const _NodeGenerator
&);
384 _M_move_assign(_Hashtable
&&, std::true_type
);
387 _M_move_assign(_Hashtable
&&, std::false_type
);
392 _Hashtable(const _H1
& __h1
, const _H2
& __h2
, const _Hash
& __h
,
393 const _Equal
& __eq
, const _ExtractKey
& __exk
,
394 const allocator_type
& __a
)
395 : __hashtable_base(__exk
, __h1
, __h2
, __h
, __eq
),
396 __hashtable_alloc(__node_alloc_type(__a
))
400 // Constructor, destructor, assignment, swap
401 _Hashtable() = default;
402 _Hashtable(size_type __bucket_hint
,
403 const _H1
&, const _H2
&, const _Hash
&,
404 const _Equal
&, const _ExtractKey
&,
405 const allocator_type
&);
407 template<typename _InputIterator
>
408 _Hashtable(_InputIterator __first
, _InputIterator __last
,
409 size_type __bucket_hint
,
410 const _H1
&, const _H2
&, const _Hash
&,
411 const _Equal
&, const _ExtractKey
&,
412 const allocator_type
&);
414 _Hashtable(const _Hashtable
&);
416 _Hashtable(_Hashtable
&&) noexcept
;
418 _Hashtable(const _Hashtable
&, const allocator_type
&);
420 _Hashtable(_Hashtable
&&, const allocator_type
&);
422 // Use delegating constructors.
424 _Hashtable(const allocator_type
& __a
)
425 : __hashtable_alloc(__node_alloc_type(__a
))
429 _Hashtable(size_type __n
,
430 const _H1
& __hf
= _H1(),
431 const key_equal
& __eql
= key_equal(),
432 const allocator_type
& __a
= allocator_type())
433 : _Hashtable(__n
, __hf
, _H2(), _Hash(), __eql
,
434 __key_extract(), __a
)
437 template<typename _InputIterator
>
438 _Hashtable(_InputIterator __f
, _InputIterator __l
,
440 const _H1
& __hf
= _H1(),
441 const key_equal
& __eql
= key_equal(),
442 const allocator_type
& __a
= allocator_type())
443 : _Hashtable(__f
, __l
, __n
, __hf
, _H2(), _Hash(), __eql
,
444 __key_extract(), __a
)
447 _Hashtable(initializer_list
<value_type
> __l
,
449 const _H1
& __hf
= _H1(),
450 const key_equal
& __eql
= key_equal(),
451 const allocator_type
& __a
= allocator_type())
452 : _Hashtable(__l
.begin(), __l
.end(), __n
, __hf
, _H2(), _Hash(), __eql
,
453 __key_extract(), __a
)
457 operator=(const _Hashtable
& __ht
);
460 operator=(_Hashtable
&& __ht
)
461 noexcept(__node_alloc_traits::_S_nothrow_move()
462 && is_nothrow_move_assignable
<_H1
>::value
463 && is_nothrow_move_assignable
<_Equal
>::value
)
465 constexpr bool __move_storage
=
466 __node_alloc_traits::_S_propagate_on_move_assign()
467 || __node_alloc_traits::_S_always_equal();
468 _M_move_assign(std::move(__ht
), __bool_constant
<__move_storage
>());
473 operator=(initializer_list
<value_type
> __l
)
475 __reuse_or_alloc_node_type
__roan(_M_begin(), *this);
476 _M_before_begin
._M_nxt
= nullptr;
478 this->_M_insert_range(__l
.begin(), __l
.end(), __roan
);
482 ~_Hashtable() noexcept
;
486 noexcept(__and_
<__is_nothrow_swappable
<_H1
>,
487 __is_nothrow_swappable
<_Equal
>>::value
);
489 // Basic container operations
492 { return iterator(_M_begin()); }
495 begin() const noexcept
496 { return const_iterator(_M_begin()); }
500 { return iterator(nullptr); }
504 { return const_iterator(nullptr); }
507 cbegin() const noexcept
508 { return const_iterator(_M_begin()); }
511 cend() const noexcept
512 { return const_iterator(nullptr); }
515 size() const noexcept
516 { return _M_element_count
; }
519 empty() const noexcept
520 { return size() == 0; }
523 get_allocator() const noexcept
524 { return allocator_type(this->_M_node_allocator()); }
527 max_size() const noexcept
528 { return __node_alloc_traits::max_size(this->_M_node_allocator()); }
533 { return this->_M_eq(); }
535 // hash_function, if present, comes from _Hash_code_base.
539 bucket_count() const noexcept
540 { return _M_bucket_count
; }
543 max_bucket_count() const noexcept
544 { return max_size(); }
547 bucket_size(size_type __n
) const
548 { return std::distance(begin(__n
), end(__n
)); }
551 bucket(const key_type
& __k
) const
552 { return _M_bucket_index(__k
, this->_M_hash_code(__k
)); }
557 return local_iterator(*this, _M_bucket_begin(__n
),
558 __n
, _M_bucket_count
);
563 { return local_iterator(*this, nullptr, __n
, _M_bucket_count
); }
566 begin(size_type __n
) const
568 return const_local_iterator(*this, _M_bucket_begin(__n
),
569 __n
, _M_bucket_count
);
573 end(size_type __n
) const
574 { return const_local_iterator(*this, nullptr, __n
, _M_bucket_count
); }
578 cbegin(size_type __n
) const
580 return const_local_iterator(*this, _M_bucket_begin(__n
),
581 __n
, _M_bucket_count
);
585 cend(size_type __n
) const
586 { return const_local_iterator(*this, nullptr, __n
, _M_bucket_count
); }
589 load_factor() const noexcept
591 return static_cast<float>(size()) / static_cast<float>(bucket_count());
594 // max_load_factor, if present, comes from _Rehash_base.
596 // Generalization of max_load_factor. Extension, not found in
597 // TR1. Only useful if _RehashPolicy is something other than
600 __rehash_policy() const
601 { return _M_rehash_policy
; }
604 __rehash_policy(const _RehashPolicy
& __pol
)
605 { _M_rehash_policy
= __pol
; }
609 find(const key_type
& __k
);
612 find(const key_type
& __k
) const;
615 count(const key_type
& __k
) const;
617 std::pair
<iterator
, iterator
>
618 equal_range(const key_type
& __k
);
620 std::pair
<const_iterator
, const_iterator
>
621 equal_range(const key_type
& __k
) const;
624 // Bucket index computation helpers.
626 _M_bucket_index(__node_type
* __n
) const noexcept
627 { return __hash_code_base::_M_bucket_index(__n
, _M_bucket_count
); }
630 _M_bucket_index(const key_type
& __k
, __hash_code __c
) const
631 { return __hash_code_base::_M_bucket_index(__k
, __c
, _M_bucket_count
); }
633 // Find and insert helper functions and types
634 // Find the node before the one matching the criteria.
636 _M_find_before_node(size_type
, const key_type
&, __hash_code
) const;
639 _M_find_node(size_type __bkt
, const key_type
& __key
,
640 __hash_code __c
) const
642 __node_base
* __before_n
= _M_find_before_node(__bkt
, __key
, __c
);
644 return static_cast<__node_type
*>(__before_n
->_M_nxt
);
648 // Insert a node at the beginning of a bucket.
650 _M_insert_bucket_begin(size_type
, __node_type
*);
652 // Remove the bucket first node
654 _M_remove_bucket_begin(size_type __bkt
, __node_type
* __next_n
,
655 size_type __next_bkt
);
657 // Get the node before __n in the bucket __bkt
659 _M_get_previous_node(size_type __bkt
, __node_base
* __n
);
661 // Insert node with hash code __code, in bucket bkt if no rehash (assumes
662 // no element with its key already present). Take ownership of the node,
663 // deallocate it on exception.
665 _M_insert_unique_node(size_type __bkt
, __hash_code __code
,
668 // Insert node with hash code __code. Take ownership of the node,
669 // deallocate it on exception.
671 _M_insert_multi_node(__node_type
* __hint
,
672 __hash_code __code
, __node_type
* __n
);
674 template<typename
... _Args
>
675 std::pair
<iterator
, bool>
676 _M_emplace(std::true_type
, _Args
&&... __args
);
678 template<typename
... _Args
>
680 _M_emplace(std::false_type __uk
, _Args
&&... __args
)
681 { return _M_emplace(cend(), __uk
, std::forward
<_Args
>(__args
)...); }
683 // Emplace with hint, useless when keys are unique.
684 template<typename
... _Args
>
686 _M_emplace(const_iterator
, std::true_type __uk
, _Args
&&... __args
)
687 { return _M_emplace(__uk
, std::forward
<_Args
>(__args
)...).first
; }
689 template<typename
... _Args
>
691 _M_emplace(const_iterator
, std::false_type
, _Args
&&... __args
);
693 template<typename _Arg
, typename _NodeGenerator
>
694 std::pair
<iterator
, bool>
695 _M_insert(_Arg
&&, const _NodeGenerator
&, std::true_type
);
697 template<typename _Arg
, typename _NodeGenerator
>
699 _M_insert(_Arg
&& __arg
, const _NodeGenerator
& __node_gen
,
700 std::false_type __uk
)
702 return _M_insert(cend(), std::forward
<_Arg
>(__arg
), __node_gen
,
706 // Insert with hint, not used when keys are unique.
707 template<typename _Arg
, typename _NodeGenerator
>
709 _M_insert(const_iterator
, _Arg
&& __arg
,
710 const _NodeGenerator
& __node_gen
, std::true_type __uk
)
713 _M_insert(std::forward
<_Arg
>(__arg
), __node_gen
, __uk
).first
;
716 // Insert with hint when keys are not unique.
717 template<typename _Arg
, typename _NodeGenerator
>
719 _M_insert(const_iterator
, _Arg
&&,
720 const _NodeGenerator
&, std::false_type
);
723 _M_erase(std::true_type
, const key_type
&);
726 _M_erase(std::false_type
, const key_type
&);
729 _M_erase(size_type __bkt
, __node_base
* __prev_n
, __node_type
* __n
);
733 template<typename
... _Args
>
735 emplace(_Args
&&... __args
)
736 { return _M_emplace(__unique_keys(), std::forward
<_Args
>(__args
)...); }
738 template<typename
... _Args
>
740 emplace_hint(const_iterator __hint
, _Args
&&... __args
)
742 return _M_emplace(__hint
, __unique_keys(),
743 std::forward
<_Args
>(__args
)...);
746 // Insert member functions via inheritance.
750 erase(const_iterator
);
755 { return erase(const_iterator(__it
)); }
758 erase(const key_type
& __k
)
759 { return _M_erase(__unique_keys(), __k
); }
762 erase(const_iterator
, const_iterator
);
767 // Set number of buckets to be appropriate for container of n element.
768 void rehash(size_type __n
);
771 // reserve, if present, comes from _Rehash_base.
773 #if __cplusplus > 201402L
774 /// Re-insert an extracted node into a container with unique keys.
776 _M_reinsert_node(node_type
&& __nh
)
778 insert_return_type __ret
;
780 __ret
.position
= end();
783 __glibcxx_assert(get_allocator() == __nh
.get_allocator());
785 const key_type
& __k
= __nh
._M_key();
786 __hash_code __code
= this->_M_hash_code(__k
);
787 size_type __bkt
= _M_bucket_index(__k
, __code
);
788 if (__node_type
* __n
= _M_find_node(__bkt
, __k
, __code
))
790 __ret
.node
= std::move(__nh
);
791 __ret
.position
= iterator(__n
);
792 __ret
.inserted
= false;
797 = _M_insert_unique_node(__bkt
, __code
, __nh
._M_ptr
);
798 __nh
._M_ptr
= nullptr;
799 __ret
.inserted
= true;
805 /// Re-insert an extracted node into a container with equivalent keys.
807 _M_reinsert_node_multi(const_iterator __hint
, node_type
&& __nh
)
814 __glibcxx_assert(get_allocator() == __nh
.get_allocator());
816 auto __code
= this->_M_hash_code(__nh
._M_key());
817 auto __node
= std::exchange(__nh
._M_ptr
, nullptr);
818 // FIXME: this deallocates the node on exception.
819 __ret
= _M_insert_multi_node(__hint
._M_cur
, __code
, __node
);
826 extract(const_iterator __pos
)
828 __node_type
* __n
= __pos
._M_cur
;
829 size_t __bkt
= _M_bucket_index(__n
);
831 // Look for previous node to unlink it from the erased one, this
832 // is why we need buckets to contain the before begin to make
834 __node_base
* __prev_n
= _M_get_previous_node(__bkt
, __n
);
836 if (__prev_n
== _M_buckets
[__bkt
])
837 _M_remove_bucket_begin(__bkt
, __n
->_M_next(),
838 __n
->_M_nxt
? _M_bucket_index(__n
->_M_next()) : 0);
839 else if (__n
->_M_nxt
)
841 size_type __next_bkt
= _M_bucket_index(__n
->_M_next());
842 if (__next_bkt
!= __bkt
)
843 _M_buckets
[__next_bkt
] = __prev_n
;
846 __prev_n
->_M_nxt
= __n
->_M_nxt
;
847 __n
->_M_nxt
= nullptr;
849 return { __n
, this->_M_node_allocator() };
854 extract(const _Key
& __k
)
857 auto __pos
= find(__k
);
859 __nh
= extract(const_iterator(__pos
));
863 /// Merge from a compatible container into one with unique keys.
864 template<typename _Compatible_Hashtable
>
866 _M_merge_unique(_Compatible_Hashtable
& __src
) noexcept
868 static_assert(is_same_v
<typename
_Compatible_Hashtable::node_type
,
869 node_type
>, "Node types are compatible");
870 __glibcxx_assert(get_allocator() == __src
.get_allocator());
872 for (auto __i
= __src
.begin(), __end
= __src
.end(); __i
!= __end
;)
875 const key_type
& __k
= this->_M_extract()(__pos
._M_cur
->_M_v());
876 __hash_code __code
= this->_M_hash_code(__k
);
877 size_type __bkt
= _M_bucket_index(__k
, __code
);
878 if (_M_find_node(__bkt
, __k
, __code
) == nullptr)
880 auto __nh
= __src
.extract(__pos
);
881 _M_insert_unique_node(__bkt
, __code
, __nh
._M_ptr
);
882 __nh
._M_ptr
= nullptr;
887 /// Merge from a compatible container into one with equivalent keys.
888 template<typename _Compatible_Hashtable
>
890 _M_merge_multi(_Compatible_Hashtable
& __src
) noexcept
892 static_assert(is_same_v
<typename
_Compatible_Hashtable::node_type
,
893 node_type
>, "Node types are compatible");
894 __glibcxx_assert(get_allocator() == __src
.get_allocator());
896 this->reserve(size() + __src
.size());
897 for (auto __i
= __src
.begin(), __end
= __src
.end(); __i
!= __end
;)
898 _M_reinsert_node_multi(cend(), __src
.extract(__i
++));
903 // Helper rehash method used when keys are unique.
904 void _M_rehash_aux(size_type __n
, std::true_type
);
906 // Helper rehash method used when keys can be non-unique.
907 void _M_rehash_aux(size_type __n
, std::false_type
);
909 // Unconditionally change size of bucket array to n, restore
910 // hash policy state to __state on exception.
911 void _M_rehash(size_type __n
, const __rehash_state
& __state
);
915 // Definitions of class template _Hashtable's out-of-line member functions.
916 template<typename _Key
, typename _Value
,
917 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
918 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
921 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
922 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
923 _M_bucket_begin(size_type __bkt
) const
926 __node_base
* __n
= _M_buckets
[__bkt
];
927 return __n
? static_cast<__node_type
*>(__n
->_M_nxt
) : nullptr;
930 template<typename _Key
, typename _Value
,
931 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
932 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
934 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
935 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
936 _Hashtable(size_type __bucket_hint
,
937 const _H1
& __h1
, const _H2
& __h2
, const _Hash
& __h
,
938 const _Equal
& __eq
, const _ExtractKey
& __exk
,
939 const allocator_type
& __a
)
940 : _Hashtable(__h1
, __h2
, __h
, __eq
, __exk
, __a
)
942 auto __bkt
= _M_rehash_policy
._M_next_bkt(__bucket_hint
);
943 if (__bkt
> _M_bucket_count
)
945 _M_buckets
= _M_allocate_buckets(__bkt
);
946 _M_bucket_count
= __bkt
;
950 template<typename _Key
, typename _Value
,
951 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
952 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
954 template<typename _InputIterator
>
955 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
956 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
957 _Hashtable(_InputIterator __f
, _InputIterator __l
,
958 size_type __bucket_hint
,
959 const _H1
& __h1
, const _H2
& __h2
, const _Hash
& __h
,
960 const _Equal
& __eq
, const _ExtractKey
& __exk
,
961 const allocator_type
& __a
)
962 : _Hashtable(__h1
, __h2
, __h
, __eq
, __exk
, __a
)
964 auto __nb_elems
= __detail::__distance_fw(__f
, __l
);
966 _M_rehash_policy
._M_next_bkt(
967 std::max(_M_rehash_policy
._M_bkt_for_elements(__nb_elems
),
970 if (__bkt_count
> _M_bucket_count
)
972 _M_buckets
= _M_allocate_buckets(__bkt_count
);
973 _M_bucket_count
= __bkt_count
;
978 for (; __f
!= __l
; ++__f
)
984 _M_deallocate_buckets();
985 __throw_exception_again
;
989 template<typename _Key
, typename _Value
,
990 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
991 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
994 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
995 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
996 operator=(const _Hashtable
& __ht
)
1002 if (__node_alloc_traits::_S_propagate_on_copy_assign())
1004 auto& __this_alloc
= this->_M_node_allocator();
1005 auto& __that_alloc
= __ht
._M_node_allocator();
1006 if (!__node_alloc_traits::_S_always_equal()
1007 && __this_alloc
!= __that_alloc
)
1009 // Replacement allocator cannot free existing storage.
1010 this->_M_deallocate_nodes(_M_begin());
1011 _M_before_begin
._M_nxt
= nullptr;
1012 _M_deallocate_buckets();
1013 _M_buckets
= nullptr;
1014 std::__alloc_on_copy(__this_alloc
, __that_alloc
);
1015 __hashtable_base::operator=(__ht
);
1016 _M_bucket_count
= __ht
._M_bucket_count
;
1017 _M_element_count
= __ht
._M_element_count
;
1018 _M_rehash_policy
= __ht
._M_rehash_policy
;
1022 [this](const __node_type
* __n
)
1023 { return this->_M_allocate_node(__n
->_M_v()); });
1027 // _M_assign took care of deallocating all memory. Now we
1028 // must make sure this instance remains in a usable state.
1030 __throw_exception_again
;
1034 std::__alloc_on_copy(__this_alloc
, __that_alloc
);
1037 // Reuse allocated buckets and nodes.
1038 __bucket_type
* __former_buckets
= nullptr;
1039 std::size_t __former_bucket_count
= _M_bucket_count
;
1040 const __rehash_state
& __former_state
= _M_rehash_policy
._M_state();
1042 if (_M_bucket_count
!= __ht
._M_bucket_count
)
1044 __former_buckets
= _M_buckets
;
1045 _M_buckets
= _M_allocate_buckets(__ht
._M_bucket_count
);
1046 _M_bucket_count
= __ht
._M_bucket_count
;
1049 __builtin_memset(_M_buckets
, 0,
1050 _M_bucket_count
* sizeof(__bucket_type
));
1054 __hashtable_base::operator=(__ht
);
1055 _M_element_count
= __ht
._M_element_count
;
1056 _M_rehash_policy
= __ht
._M_rehash_policy
;
1057 __reuse_or_alloc_node_type
__roan(_M_begin(), *this);
1058 _M_before_begin
._M_nxt
= nullptr;
1060 [&__roan
](const __node_type
* __n
)
1061 { return __roan(__n
->_M_v()); });
1062 if (__former_buckets
)
1063 _M_deallocate_buckets(__former_buckets
, __former_bucket_count
);
1067 if (__former_buckets
)
1069 // Restore previous buckets.
1070 _M_deallocate_buckets();
1071 _M_rehash_policy
._M_reset(__former_state
);
1072 _M_buckets
= __former_buckets
;
1073 _M_bucket_count
= __former_bucket_count
;
1075 __builtin_memset(_M_buckets
, 0,
1076 _M_bucket_count
* sizeof(__bucket_type
));
1077 __throw_exception_again
;
1082 template<typename _Key
, typename _Value
,
1083 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1084 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1086 template<typename _NodeGenerator
>
1088 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1089 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1090 _M_assign(const _Hashtable
& __ht
, const _NodeGenerator
& __node_gen
)
1092 __bucket_type
* __buckets
= nullptr;
1094 _M_buckets
= __buckets
= _M_allocate_buckets(_M_bucket_count
);
1098 if (!__ht
._M_before_begin
._M_nxt
)
1101 // First deal with the special first node pointed to by
1103 __node_type
* __ht_n
= __ht
._M_begin();
1104 __node_type
* __this_n
= __node_gen(__ht_n
);
1105 this->_M_copy_code(__this_n
, __ht_n
);
1106 _M_before_begin
._M_nxt
= __this_n
;
1107 _M_buckets
[_M_bucket_index(__this_n
)] = &_M_before_begin
;
1109 // Then deal with other nodes.
1110 __node_base
* __prev_n
= __this_n
;
1111 for (__ht_n
= __ht_n
->_M_next(); __ht_n
; __ht_n
= __ht_n
->_M_next())
1113 __this_n
= __node_gen(__ht_n
);
1114 __prev_n
->_M_nxt
= __this_n
;
1115 this->_M_copy_code(__this_n
, __ht_n
);
1116 size_type __bkt
= _M_bucket_index(__this_n
);
1117 if (!_M_buckets
[__bkt
])
1118 _M_buckets
[__bkt
] = __prev_n
;
1119 __prev_n
= __this_n
;
1126 _M_deallocate_buckets();
1127 __throw_exception_again
;
1131 template<typename _Key
, typename _Value
,
1132 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1133 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1136 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1137 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1140 _M_rehash_policy
._M_reset();
1141 _M_bucket_count
= 1;
1142 _M_single_bucket
= nullptr;
1143 _M_buckets
= &_M_single_bucket
;
1144 _M_before_begin
._M_nxt
= nullptr;
1145 _M_element_count
= 0;
1148 template<typename _Key
, typename _Value
,
1149 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1150 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1153 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1154 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1155 _M_move_assign(_Hashtable
&& __ht
, std::true_type
)
1157 this->_M_deallocate_nodes(_M_begin());
1158 _M_deallocate_buckets();
1159 __hashtable_base::operator=(std::move(__ht
));
1160 _M_rehash_policy
= __ht
._M_rehash_policy
;
1161 if (!__ht
._M_uses_single_bucket())
1162 _M_buckets
= __ht
._M_buckets
;
1165 _M_buckets
= &_M_single_bucket
;
1166 _M_single_bucket
= __ht
._M_single_bucket
;
1168 _M_bucket_count
= __ht
._M_bucket_count
;
1169 _M_before_begin
._M_nxt
= __ht
._M_before_begin
._M_nxt
;
1170 _M_element_count
= __ht
._M_element_count
;
1171 std::__alloc_on_move(this->_M_node_allocator(), __ht
._M_node_allocator());
1173 // Fix buckets containing the _M_before_begin pointers that can't be
1176 _M_buckets
[_M_bucket_index(_M_begin())] = &_M_before_begin
;
1180 template<typename _Key
, typename _Value
,
1181 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1182 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1185 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1186 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1187 _M_move_assign(_Hashtable
&& __ht
, std::false_type
)
1189 if (__ht
._M_node_allocator() == this->_M_node_allocator())
1190 _M_move_assign(std::move(__ht
), std::true_type());
1193 // Can't move memory, move elements then.
1194 __bucket_type
* __former_buckets
= nullptr;
1195 size_type __former_bucket_count
= _M_bucket_count
;
1196 const __rehash_state
& __former_state
= _M_rehash_policy
._M_state();
1198 if (_M_bucket_count
!= __ht
._M_bucket_count
)
1200 __former_buckets
= _M_buckets
;
1201 _M_buckets
= _M_allocate_buckets(__ht
._M_bucket_count
);
1202 _M_bucket_count
= __ht
._M_bucket_count
;
1205 __builtin_memset(_M_buckets
, 0,
1206 _M_bucket_count
* sizeof(__bucket_type
));
1210 __hashtable_base::operator=(std::move(__ht
));
1211 _M_element_count
= __ht
._M_element_count
;
1212 _M_rehash_policy
= __ht
._M_rehash_policy
;
1213 __reuse_or_alloc_node_type
__roan(_M_begin(), *this);
1214 _M_before_begin
._M_nxt
= nullptr;
1216 [&__roan
](__node_type
* __n
)
1217 { return __roan(std::move_if_noexcept(__n
->_M_v())); });
1222 if (__former_buckets
)
1224 _M_deallocate_buckets();
1225 _M_rehash_policy
._M_reset(__former_state
);
1226 _M_buckets
= __former_buckets
;
1227 _M_bucket_count
= __former_bucket_count
;
1229 __builtin_memset(_M_buckets
, 0,
1230 _M_bucket_count
* sizeof(__bucket_type
));
1231 __throw_exception_again
;
1236 template<typename _Key
, typename _Value
,
1237 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1238 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1240 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1241 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1242 _Hashtable(const _Hashtable
& __ht
)
1243 : __hashtable_base(__ht
),
1245 __rehash_base(__ht
),
1247 __node_alloc_traits::_S_select_on_copy(__ht
._M_node_allocator())),
1248 _M_buckets(nullptr),
1249 _M_bucket_count(__ht
._M_bucket_count
),
1250 _M_element_count(__ht
._M_element_count
),
1251 _M_rehash_policy(__ht
._M_rehash_policy
)
1254 [this](const __node_type
* __n
)
1255 { return this->_M_allocate_node(__n
->_M_v()); });
1258 template<typename _Key
, typename _Value
,
1259 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1260 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1262 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1263 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1264 _Hashtable(_Hashtable
&& __ht
) noexcept
1265 : __hashtable_base(__ht
),
1267 __rehash_base(__ht
),
1268 __hashtable_alloc(std::move(__ht
._M_base_alloc())),
1269 _M_buckets(__ht
._M_buckets
),
1270 _M_bucket_count(__ht
._M_bucket_count
),
1271 _M_before_begin(__ht
._M_before_begin
._M_nxt
),
1272 _M_element_count(__ht
._M_element_count
),
1273 _M_rehash_policy(__ht
._M_rehash_policy
)
1275 // Update, if necessary, buckets if __ht is using its single bucket.
1276 if (__ht
._M_uses_single_bucket())
1278 _M_buckets
= &_M_single_bucket
;
1279 _M_single_bucket
= __ht
._M_single_bucket
;
1282 // Update, if necessary, bucket pointing to before begin that hasn't
1285 _M_buckets
[_M_bucket_index(_M_begin())] = &_M_before_begin
;
1290 template<typename _Key
, typename _Value
,
1291 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1292 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1294 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1295 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1296 _Hashtable(const _Hashtable
& __ht
, const allocator_type
& __a
)
1297 : __hashtable_base(__ht
),
1299 __rehash_base(__ht
),
1300 __hashtable_alloc(__node_alloc_type(__a
)),
1302 _M_bucket_count(__ht
._M_bucket_count
),
1303 _M_element_count(__ht
._M_element_count
),
1304 _M_rehash_policy(__ht
._M_rehash_policy
)
1307 [this](const __node_type
* __n
)
1308 { return this->_M_allocate_node(__n
->_M_v()); });
1311 template<typename _Key
, typename _Value
,
1312 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1313 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1315 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1316 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1317 _Hashtable(_Hashtable
&& __ht
, const allocator_type
& __a
)
1318 : __hashtable_base(__ht
),
1320 __rehash_base(__ht
),
1321 __hashtable_alloc(__node_alloc_type(__a
)),
1322 _M_buckets(nullptr),
1323 _M_bucket_count(__ht
._M_bucket_count
),
1324 _M_element_count(__ht
._M_element_count
),
1325 _M_rehash_policy(__ht
._M_rehash_policy
)
1327 if (__ht
._M_node_allocator() == this->_M_node_allocator())
1329 if (__ht
._M_uses_single_bucket())
1331 _M_buckets
= &_M_single_bucket
;
1332 _M_single_bucket
= __ht
._M_single_bucket
;
1335 _M_buckets
= __ht
._M_buckets
;
1337 _M_before_begin
._M_nxt
= __ht
._M_before_begin
._M_nxt
;
1338 // Update, if necessary, bucket pointing to before begin that hasn't
1341 _M_buckets
[_M_bucket_index(_M_begin())] = &_M_before_begin
;
1347 [this](__node_type
* __n
)
1349 return this->_M_allocate_node(
1350 std::move_if_noexcept(__n
->_M_v()));
1356 template<typename _Key
, typename _Value
,
1357 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1358 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1360 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1361 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1362 ~_Hashtable() noexcept
1365 _M_deallocate_buckets();
1368 template<typename _Key
, typename _Value
,
1369 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1370 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1373 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1374 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1375 swap(_Hashtable
& __x
)
1376 noexcept(__and_
<__is_nothrow_swappable
<_H1
>,
1377 __is_nothrow_swappable
<_Equal
>>::value
)
1379 // The only base class with member variables is hash_code_base.
1380 // We define _Hash_code_base::_M_swap because different
1381 // specializations have different members.
1384 std::__alloc_on_swap(this->_M_node_allocator(), __x
._M_node_allocator());
1385 std::swap(_M_rehash_policy
, __x
._M_rehash_policy
);
1387 // Deal properly with potentially moved instances.
1388 if (this->_M_uses_single_bucket())
1390 if (!__x
._M_uses_single_bucket())
1392 _M_buckets
= __x
._M_buckets
;
1393 __x
._M_buckets
= &__x
._M_single_bucket
;
1396 else if (__x
._M_uses_single_bucket())
1398 __x
._M_buckets
= _M_buckets
;
1399 _M_buckets
= &_M_single_bucket
;
1402 std::swap(_M_buckets
, __x
._M_buckets
);
1404 std::swap(_M_bucket_count
, __x
._M_bucket_count
);
1405 std::swap(_M_before_begin
._M_nxt
, __x
._M_before_begin
._M_nxt
);
1406 std::swap(_M_element_count
, __x
._M_element_count
);
1407 std::swap(_M_single_bucket
, __x
._M_single_bucket
);
1409 // Fix buckets containing the _M_before_begin pointers that can't be
1412 _M_buckets
[_M_bucket_index(_M_begin())] = &_M_before_begin
;
1415 __x
._M_buckets
[__x
._M_bucket_index(__x
._M_begin())]
1416 = &__x
._M_before_begin
;
1419 template<typename _Key
, typename _Value
,
1420 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1421 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1424 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1425 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1426 find(const key_type
& __k
)
1429 __hash_code __code
= this->_M_hash_code(__k
);
1430 std::size_t __n
= _M_bucket_index(__k
, __code
);
1431 __node_type
* __p
= _M_find_node(__n
, __k
, __code
);
1432 return __p
? iterator(__p
) : end();
1435 template<typename _Key
, typename _Value
,
1436 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1437 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1440 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1441 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1442 find(const key_type
& __k
) const
1445 __hash_code __code
= this->_M_hash_code(__k
);
1446 std::size_t __n
= _M_bucket_index(__k
, __code
);
1447 __node_type
* __p
= _M_find_node(__n
, __k
, __code
);
1448 return __p
? const_iterator(__p
) : end();
1451 template<typename _Key
, typename _Value
,
1452 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1453 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1456 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1457 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1458 count(const key_type
& __k
) const
1461 __hash_code __code
= this->_M_hash_code(__k
);
1462 std::size_t __n
= _M_bucket_index(__k
, __code
);
1463 __node_type
* __p
= _M_bucket_begin(__n
);
1467 std::size_t __result
= 0;
1468 for (;; __p
= __p
->_M_next())
1470 if (this->_M_equals(__k
, __code
, __p
))
1473 // All equivalent values are next to each other, if we
1474 // found a non-equivalent value after an equivalent one it
1475 // means that we won't find any new equivalent value.
1477 if (!__p
->_M_nxt
|| _M_bucket_index(__p
->_M_next()) != __n
)
1483 template<typename _Key
, typename _Value
,
1484 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1485 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1488 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1489 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1490 equal_range(const key_type
& __k
)
1491 -> pair
<iterator
, iterator
>
1493 __hash_code __code
= this->_M_hash_code(__k
);
1494 std::size_t __n
= _M_bucket_index(__k
, __code
);
1495 __node_type
* __p
= _M_find_node(__n
, __k
, __code
);
1499 __node_type
* __p1
= __p
->_M_next();
1500 while (__p1
&& _M_bucket_index(__p1
) == __n
1501 && this->_M_equals(__k
, __code
, __p1
))
1502 __p1
= __p1
->_M_next();
1504 return std::make_pair(iterator(__p
), iterator(__p1
));
1507 return std::make_pair(end(), end());
1510 template<typename _Key
, typename _Value
,
1511 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1512 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1515 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1516 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1517 equal_range(const key_type
& __k
) const
1518 -> pair
<const_iterator
, const_iterator
>
1520 __hash_code __code
= this->_M_hash_code(__k
);
1521 std::size_t __n
= _M_bucket_index(__k
, __code
);
1522 __node_type
* __p
= _M_find_node(__n
, __k
, __code
);
1526 __node_type
* __p1
= __p
->_M_next();
1527 while (__p1
&& _M_bucket_index(__p1
) == __n
1528 && this->_M_equals(__k
, __code
, __p1
))
1529 __p1
= __p1
->_M_next();
1531 return std::make_pair(const_iterator(__p
), const_iterator(__p1
));
1534 return std::make_pair(end(), end());
1537 // Find the node whose key compares equal to k in the bucket n.
1538 // Return nullptr if no node is found.
1539 template<typename _Key
, typename _Value
,
1540 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1541 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1544 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1545 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1546 _M_find_before_node(size_type __n
, const key_type
& __k
,
1547 __hash_code __code
) const
1550 __node_base
* __prev_p
= _M_buckets
[__n
];
1554 for (__node_type
* __p
= static_cast<__node_type
*>(__prev_p
->_M_nxt
);;
1555 __p
= __p
->_M_next())
1557 if (this->_M_equals(__k
, __code
, __p
))
1560 if (!__p
->_M_nxt
|| _M_bucket_index(__p
->_M_next()) != __n
)
1567 template<typename _Key
, typename _Value
,
1568 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1569 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1572 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1573 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1574 _M_insert_bucket_begin(size_type __bkt
, __node_type
* __node
)
1576 if (_M_buckets
[__bkt
])
1578 // Bucket is not empty, we just need to insert the new node
1579 // after the bucket before begin.
1580 __node
->_M_nxt
= _M_buckets
[__bkt
]->_M_nxt
;
1581 _M_buckets
[__bkt
]->_M_nxt
= __node
;
1585 // The bucket is empty, the new node is inserted at the
1586 // beginning of the singly-linked list and the bucket will
1587 // contain _M_before_begin pointer.
1588 __node
->_M_nxt
= _M_before_begin
._M_nxt
;
1589 _M_before_begin
._M_nxt
= __node
;
1591 // We must update former begin bucket that is pointing to
1593 _M_buckets
[_M_bucket_index(__node
->_M_next())] = __node
;
1594 _M_buckets
[__bkt
] = &_M_before_begin
;
1598 template<typename _Key
, typename _Value
,
1599 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1600 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1603 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1604 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1605 _M_remove_bucket_begin(size_type __bkt
, __node_type
* __next
,
1606 size_type __next_bkt
)
1608 if (!__next
|| __next_bkt
!= __bkt
)
1610 // Bucket is now empty
1611 // First update next bucket if any
1613 _M_buckets
[__next_bkt
] = _M_buckets
[__bkt
];
1615 // Second update before begin node if necessary
1616 if (&_M_before_begin
== _M_buckets
[__bkt
])
1617 _M_before_begin
._M_nxt
= __next
;
1618 _M_buckets
[__bkt
] = nullptr;
1622 template<typename _Key
, typename _Value
,
1623 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1624 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1627 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1628 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1629 _M_get_previous_node(size_type __bkt
, __node_base
* __n
)
1632 __node_base
* __prev_n
= _M_buckets
[__bkt
];
1633 while (__prev_n
->_M_nxt
!= __n
)
1634 __prev_n
= __prev_n
->_M_nxt
;
1638 template<typename _Key
, typename _Value
,
1639 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1640 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1642 template<typename
... _Args
>
1644 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1645 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1646 _M_emplace(std::true_type
, _Args
&&... __args
)
1647 -> pair
<iterator
, bool>
1649 // First build the node to get access to the hash code
1650 __node_type
* __node
= this->_M_allocate_node(std::forward
<_Args
>(__args
)...);
1651 const key_type
& __k
= this->_M_extract()(__node
->_M_v());
1655 __code
= this->_M_hash_code(__k
);
1659 this->_M_deallocate_node(__node
);
1660 __throw_exception_again
;
1663 size_type __bkt
= _M_bucket_index(__k
, __code
);
1664 if (__node_type
* __p
= _M_find_node(__bkt
, __k
, __code
))
1666 // There is already an equivalent node, no insertion
1667 this->_M_deallocate_node(__node
);
1668 return std::make_pair(iterator(__p
), false);
1672 return std::make_pair(_M_insert_unique_node(__bkt
, __code
, __node
),
1676 template<typename _Key
, typename _Value
,
1677 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1678 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1680 template<typename
... _Args
>
1682 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1683 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1684 _M_emplace(const_iterator __hint
, std::false_type
, _Args
&&... __args
)
1687 // First build the node to get its hash code.
1688 __node_type
* __node
=
1689 this->_M_allocate_node(std::forward
<_Args
>(__args
)...);
1694 __code
= this->_M_hash_code(this->_M_extract()(__node
->_M_v()));
1698 this->_M_deallocate_node(__node
);
1699 __throw_exception_again
;
1702 return _M_insert_multi_node(__hint
._M_cur
, __code
, __node
);
1705 template<typename _Key
, typename _Value
,
1706 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1707 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1710 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1711 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1712 _M_insert_unique_node(size_type __bkt
, __hash_code __code
,
1713 __node_type
* __node
)
1716 const __rehash_state
& __saved_state
= _M_rehash_policy
._M_state();
1717 std::pair
<bool, std::size_t> __do_rehash
1718 = _M_rehash_policy
._M_need_rehash(_M_bucket_count
, _M_element_count
, 1);
1722 if (__do_rehash
.first
)
1724 _M_rehash(__do_rehash
.second
, __saved_state
);
1725 __bkt
= _M_bucket_index(this->_M_extract()(__node
->_M_v()), __code
);
1728 this->_M_store_code(__node
, __code
);
1730 // Always insert at the beginning of the bucket.
1731 _M_insert_bucket_begin(__bkt
, __node
);
1733 return iterator(__node
);
1737 this->_M_deallocate_node(__node
);
1738 __throw_exception_again
;
1742 // Insert node, in bucket bkt if no rehash (assumes no element with its key
1743 // already present). Take ownership of the node, deallocate it on exception.
1744 template<typename _Key
, typename _Value
,
1745 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1746 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1749 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1750 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1751 _M_insert_multi_node(__node_type
* __hint
, __hash_code __code
,
1752 __node_type
* __node
)
1755 const __rehash_state
& __saved_state
= _M_rehash_policy
._M_state();
1756 std::pair
<bool, std::size_t> __do_rehash
1757 = _M_rehash_policy
._M_need_rehash(_M_bucket_count
, _M_element_count
, 1);
1761 if (__do_rehash
.first
)
1762 _M_rehash(__do_rehash
.second
, __saved_state
);
1764 this->_M_store_code(__node
, __code
);
1765 const key_type
& __k
= this->_M_extract()(__node
->_M_v());
1766 size_type __bkt
= _M_bucket_index(__k
, __code
);
1768 // Find the node before an equivalent one or use hint if it exists and
1769 // if it is equivalent.
1771 = __builtin_expect(__hint
!= nullptr, false)
1772 && this->_M_equals(__k
, __code
, __hint
)
1774 : _M_find_before_node(__bkt
, __k
, __code
);
1777 // Insert after the node before the equivalent one.
1778 __node
->_M_nxt
= __prev
->_M_nxt
;
1779 __prev
->_M_nxt
= __node
;
1780 if (__builtin_expect(__prev
== __hint
, false))
1781 // hint might be the last bucket node, in this case we need to
1782 // update next bucket.
1784 && !this->_M_equals(__k
, __code
, __node
->_M_next()))
1786 size_type __next_bkt
= _M_bucket_index(__node
->_M_next());
1787 if (__next_bkt
!= __bkt
)
1788 _M_buckets
[__next_bkt
] = __node
;
1792 // The inserted node has no equivalent in the
1793 // hashtable. We must insert the new node at the
1794 // beginning of the bucket to preserve equivalent
1795 // elements' relative positions.
1796 _M_insert_bucket_begin(__bkt
, __node
);
1798 return iterator(__node
);
1802 this->_M_deallocate_node(__node
);
1803 __throw_exception_again
;
1807 // Insert v if no element with its key is already present.
1808 template<typename _Key
, typename _Value
,
1809 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1810 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1812 template<typename _Arg
, typename _NodeGenerator
>
1814 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1815 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1816 _M_insert(_Arg
&& __v
, const _NodeGenerator
& __node_gen
, std::true_type
)
1817 -> pair
<iterator
, bool>
1819 const key_type
& __k
= this->_M_extract()(__v
);
1820 __hash_code __code
= this->_M_hash_code(__k
);
1821 size_type __bkt
= _M_bucket_index(__k
, __code
);
1823 __node_type
* __n
= _M_find_node(__bkt
, __k
, __code
);
1825 return std::make_pair(iterator(__n
), false);
1827 __n
= __node_gen(std::forward
<_Arg
>(__v
));
1828 return std::make_pair(_M_insert_unique_node(__bkt
, __code
, __n
), true);
1831 // Insert v unconditionally.
1832 template<typename _Key
, typename _Value
,
1833 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1834 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1836 template<typename _Arg
, typename _NodeGenerator
>
1838 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1839 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1840 _M_insert(const_iterator __hint
, _Arg
&& __v
,
1841 const _NodeGenerator
& __node_gen
, std::false_type
)
1844 // First compute the hash code so that we don't do anything if it
1846 __hash_code __code
= this->_M_hash_code(this->_M_extract()(__v
));
1848 // Second allocate new node so that we don't rehash if it throws.
1849 __node_type
* __node
= __node_gen(std::forward
<_Arg
>(__v
));
1851 return _M_insert_multi_node(__hint
._M_cur
, __code
, __node
);
1854 template<typename _Key
, typename _Value
,
1855 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1856 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1859 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1860 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1861 erase(const_iterator __it
)
1864 __node_type
* __n
= __it
._M_cur
;
1865 std::size_t __bkt
= _M_bucket_index(__n
);
1867 // Look for previous node to unlink it from the erased one, this
1868 // is why we need buckets to contain the before begin to make
1869 // this search fast.
1870 __node_base
* __prev_n
= _M_get_previous_node(__bkt
, __n
);
1871 return _M_erase(__bkt
, __prev_n
, __n
);
1874 template<typename _Key
, typename _Value
,
1875 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1876 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1879 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1880 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1881 _M_erase(size_type __bkt
, __node_base
* __prev_n
, __node_type
* __n
)
1884 if (__prev_n
== _M_buckets
[__bkt
])
1885 _M_remove_bucket_begin(__bkt
, __n
->_M_next(),
1886 __n
->_M_nxt
? _M_bucket_index(__n
->_M_next()) : 0);
1887 else if (__n
->_M_nxt
)
1889 size_type __next_bkt
= _M_bucket_index(__n
->_M_next());
1890 if (__next_bkt
!= __bkt
)
1891 _M_buckets
[__next_bkt
] = __prev_n
;
1894 __prev_n
->_M_nxt
= __n
->_M_nxt
;
1895 iterator
__result(__n
->_M_next());
1896 this->_M_deallocate_node(__n
);
1902 template<typename _Key
, typename _Value
,
1903 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1904 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1907 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1908 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1909 _M_erase(std::true_type
, const key_type
& __k
)
1912 __hash_code __code
= this->_M_hash_code(__k
);
1913 std::size_t __bkt
= _M_bucket_index(__k
, __code
);
1915 // Look for the node before the first matching node.
1916 __node_base
* __prev_n
= _M_find_before_node(__bkt
, __k
, __code
);
1920 // We found a matching node, erase it.
1921 __node_type
* __n
= static_cast<__node_type
*>(__prev_n
->_M_nxt
);
1922 _M_erase(__bkt
, __prev_n
, __n
);
1926 template<typename _Key
, typename _Value
,
1927 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1928 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1931 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1932 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1933 _M_erase(std::false_type
, const key_type
& __k
)
1936 __hash_code __code
= this->_M_hash_code(__k
);
1937 std::size_t __bkt
= _M_bucket_index(__k
, __code
);
1939 // Look for the node before the first matching node.
1940 __node_base
* __prev_n
= _M_find_before_node(__bkt
, __k
, __code
);
1944 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1945 // 526. Is it undefined if a function in the standard changes
1947 // We use one loop to find all matching nodes and another to deallocate
1948 // them so that the key stays valid during the first loop. It might be
1949 // invalidated indirectly when destroying nodes.
1950 __node_type
* __n
= static_cast<__node_type
*>(__prev_n
->_M_nxt
);
1951 __node_type
* __n_last
= __n
;
1952 std::size_t __n_last_bkt
= __bkt
;
1955 __n_last
= __n_last
->_M_next();
1958 __n_last_bkt
= _M_bucket_index(__n_last
);
1960 while (__n_last_bkt
== __bkt
&& this->_M_equals(__k
, __code
, __n_last
));
1962 // Deallocate nodes.
1963 size_type __result
= 0;
1966 __node_type
* __p
= __n
->_M_next();
1967 this->_M_deallocate_node(__n
);
1972 while (__n
!= __n_last
);
1974 if (__prev_n
== _M_buckets
[__bkt
])
1975 _M_remove_bucket_begin(__bkt
, __n_last
, __n_last_bkt
);
1976 else if (__n_last
&& __n_last_bkt
!= __bkt
)
1977 _M_buckets
[__n_last_bkt
] = __prev_n
;
1978 __prev_n
->_M_nxt
= __n_last
;
1982 template<typename _Key
, typename _Value
,
1983 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
1984 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
1987 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
1988 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
1989 erase(const_iterator __first
, const_iterator __last
)
1992 __node_type
* __n
= __first
._M_cur
;
1993 __node_type
* __last_n
= __last
._M_cur
;
1994 if (__n
== __last_n
)
1995 return iterator(__n
);
1997 std::size_t __bkt
= _M_bucket_index(__n
);
1999 __node_base
* __prev_n
= _M_get_previous_node(__bkt
, __n
);
2000 bool __is_bucket_begin
= __n
== _M_bucket_begin(__bkt
);
2001 std::size_t __n_bkt
= __bkt
;
2006 __node_type
* __tmp
= __n
;
2007 __n
= __n
->_M_next();
2008 this->_M_deallocate_node(__tmp
);
2012 __n_bkt
= _M_bucket_index(__n
);
2014 while (__n
!= __last_n
&& __n_bkt
== __bkt
);
2015 if (__is_bucket_begin
)
2016 _M_remove_bucket_begin(__bkt
, __n
, __n_bkt
);
2017 if (__n
== __last_n
)
2019 __is_bucket_begin
= true;
2023 if (__n
&& (__n_bkt
!= __bkt
|| __is_bucket_begin
))
2024 _M_buckets
[__n_bkt
] = __prev_n
;
2025 __prev_n
->_M_nxt
= __n
;
2026 return iterator(__n
);
2029 template<typename _Key
, typename _Value
,
2030 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
2031 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
2034 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
2035 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
2038 this->_M_deallocate_nodes(_M_begin());
2039 __builtin_memset(_M_buckets
, 0, _M_bucket_count
* sizeof(__bucket_type
));
2040 _M_element_count
= 0;
2041 _M_before_begin
._M_nxt
= nullptr;
2044 template<typename _Key
, typename _Value
,
2045 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
2046 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
2049 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
2050 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
2051 rehash(size_type __n
)
2053 const __rehash_state
& __saved_state
= _M_rehash_policy
._M_state();
2054 std::size_t __buckets
2055 = std::max(_M_rehash_policy
._M_bkt_for_elements(_M_element_count
+ 1),
2057 __buckets
= _M_rehash_policy
._M_next_bkt(__buckets
);
2059 if (__buckets
!= _M_bucket_count
)
2060 _M_rehash(__buckets
, __saved_state
);
2062 // No rehash, restore previous state to keep a consistent state.
2063 _M_rehash_policy
._M_reset(__saved_state
);
2066 template<typename _Key
, typename _Value
,
2067 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
2068 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
2071 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
2072 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
2073 _M_rehash(size_type __n
, const __rehash_state
& __state
)
2077 _M_rehash_aux(__n
, __unique_keys());
2081 // A failure here means that buckets allocation failed. We only
2082 // have to restore hash policy previous state.
2083 _M_rehash_policy
._M_reset(__state
);
2084 __throw_exception_again
;
2088 // Rehash when there is no equivalent elements.
2089 template<typename _Key
, typename _Value
,
2090 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
2091 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
2094 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
2095 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
2096 _M_rehash_aux(size_type __n
, std::true_type
)
2098 __bucket_type
* __new_buckets
= _M_allocate_buckets(__n
);
2099 __node_type
* __p
= _M_begin();
2100 _M_before_begin
._M_nxt
= nullptr;
2101 std::size_t __bbegin_bkt
= 0;
2104 __node_type
* __next
= __p
->_M_next();
2105 std::size_t __bkt
= __hash_code_base::_M_bucket_index(__p
, __n
);
2106 if (!__new_buckets
[__bkt
])
2108 __p
->_M_nxt
= _M_before_begin
._M_nxt
;
2109 _M_before_begin
._M_nxt
= __p
;
2110 __new_buckets
[__bkt
] = &_M_before_begin
;
2112 __new_buckets
[__bbegin_bkt
] = __p
;
2113 __bbegin_bkt
= __bkt
;
2117 __p
->_M_nxt
= __new_buckets
[__bkt
]->_M_nxt
;
2118 __new_buckets
[__bkt
]->_M_nxt
= __p
;
2123 _M_deallocate_buckets();
2124 _M_bucket_count
= __n
;
2125 _M_buckets
= __new_buckets
;
2128 // Rehash when there can be equivalent elements, preserve their relative
2130 template<typename _Key
, typename _Value
,
2131 typename _Alloc
, typename _ExtractKey
, typename _Equal
,
2132 typename _H1
, typename _H2
, typename _Hash
, typename _RehashPolicy
,
2135 _Hashtable
<_Key
, _Value
, _Alloc
, _ExtractKey
, _Equal
,
2136 _H1
, _H2
, _Hash
, _RehashPolicy
, _Traits
>::
2137 _M_rehash_aux(size_type __n
, std::false_type
)
2139 __bucket_type
* __new_buckets
= _M_allocate_buckets(__n
);
2141 __node_type
* __p
= _M_begin();
2142 _M_before_begin
._M_nxt
= nullptr;
2143 std::size_t __bbegin_bkt
= 0;
2144 std::size_t __prev_bkt
= 0;
2145 __node_type
* __prev_p
= nullptr;
2146 bool __check_bucket
= false;
2150 __node_type
* __next
= __p
->_M_next();
2151 std::size_t __bkt
= __hash_code_base::_M_bucket_index(__p
, __n
);
2153 if (__prev_p
&& __prev_bkt
== __bkt
)
2155 // Previous insert was already in this bucket, we insert after
2156 // the previously inserted one to preserve equivalent elements
2158 __p
->_M_nxt
= __prev_p
->_M_nxt
;
2159 __prev_p
->_M_nxt
= __p
;
2161 // Inserting after a node in a bucket require to check that we
2162 // haven't change the bucket last node, in this case next
2163 // bucket containing its before begin node must be updated. We
2164 // schedule a check as soon as we move out of the sequence of
2165 // equivalent nodes to limit the number of checks.
2166 __check_bucket
= true;
2172 // Check if we shall update the next bucket because of
2173 // insertions into __prev_bkt bucket.
2174 if (__prev_p
->_M_nxt
)
2176 std::size_t __next_bkt
2177 = __hash_code_base::_M_bucket_index(__prev_p
->_M_next(),
2179 if (__next_bkt
!= __prev_bkt
)
2180 __new_buckets
[__next_bkt
] = __prev_p
;
2182 __check_bucket
= false;
2185 if (!__new_buckets
[__bkt
])
2187 __p
->_M_nxt
= _M_before_begin
._M_nxt
;
2188 _M_before_begin
._M_nxt
= __p
;
2189 __new_buckets
[__bkt
] = &_M_before_begin
;
2191 __new_buckets
[__bbegin_bkt
] = __p
;
2192 __bbegin_bkt
= __bkt
;
2196 __p
->_M_nxt
= __new_buckets
[__bkt
]->_M_nxt
;
2197 __new_buckets
[__bkt
]->_M_nxt
= __p
;
2205 if (__check_bucket
&& __prev_p
->_M_nxt
)
2207 std::size_t __next_bkt
2208 = __hash_code_base::_M_bucket_index(__prev_p
->_M_next(), __n
);
2209 if (__next_bkt
!= __prev_bkt
)
2210 __new_buckets
[__next_bkt
] = __prev_p
;
2213 _M_deallocate_buckets();
2214 _M_bucket_count
= __n
;
2215 _M_buckets
= __new_buckets
;
2218 #if __cplusplus > 201402L
2219 template<typename
, typename
, typename
> class _Hash_merge_helper
{ };
2222 _GLIBCXX_END_NAMESPACE_VERSION
2225 #endif // _HASHTABLE_H