1// Internal policy header for unordered_set and unordered_map -*- C++ -*-
2
3// Copyright (C) 2010-2018 Free Software Foundation, Inc.
4//
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)
9// any later version.
10
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.
15
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.
19
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/>.
24
25/** @file bits/hashtable_policy.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly.
28 * @headername{unordered_map,unordered_set}
29 */
30
31#ifndef _HASHTABLE_POLICY_H
32#define _HASHTABLE_POLICY_H 1
33
34#include <tuple> // for std::tuple, std::forward_as_tuple
35#include <cstdint> // for std::uint_fast64_t
36#include <bits/stl_algobase.h> // for std::min.
37
38namespace std _GLIBCXX_VISIBILITY(default)
39{
40_GLIBCXX_BEGIN_NAMESPACE_VERSION
41
42 template<typename _Key, typename _Value, typename _Alloc,
43 typename _ExtractKey, typename _Equal,
44 typename _H1, typename _H2, typename _Hash,
45 typename _RehashPolicy, typename _Traits>
46 class _Hashtable;
47
48namespace __detail
49{
50 /**
51 * @defgroup hashtable-detail Base and Implementation Classes
52 * @ingroup unordered_associative_containers
53 * @{
54 */
55 template<typename _Key, typename _Value,
56 typename _ExtractKey, typename _Equal,
57 typename _H1, typename _H2, typename _Hash, typename _Traits>
58 struct _Hashtable_base;
59
60 // Helper function: return distance(first, last) for forward
61 // iterators, or 0/1 for input iterators.
62 template<class _Iterator>
63 inline typename std::iterator_traits<_Iterator>::difference_type
64 __distance_fw(_Iterator __first, _Iterator __last,
65 std::input_iterator_tag)
66 { return __first != __last ? 1 : 0; }
67
68 template<class _Iterator>
69 inline typename std::iterator_traits<_Iterator>::difference_type
70 __distance_fw(_Iterator __first, _Iterator __last,
71 std::forward_iterator_tag)
72 { return std::distance(__first, __last); }
73
74 template<class _Iterator>
75 inline typename std::iterator_traits<_Iterator>::difference_type
76 __distance_fw(_Iterator __first, _Iterator __last)
77 { return __distance_fw(__first, __last,
78 std::__iterator_category(__first)); }
79
80 struct _Identity
81 {
82 template<typename _Tp>
83 _Tp&&
84 operator()(_Tp&& __x) const
85 { return std::forward<_Tp>(__x); }
86 };
87
88 struct _Select1st
89 {
90 template<typename _Tp>
91 auto
92 operator()(_Tp&& __x) const
93 -> decltype(std::get<0>(std::forward<_Tp>(__x)))
94 { return std::get<0>(std::forward<_Tp>(__x)); }
95 };
96
97 template<typename _NodeAlloc>
98 struct _Hashtable_alloc;
99
100 // Functor recycling a pool of nodes and using allocation once the pool is
101 // empty.
102 template<typename _NodeAlloc>
103 struct _ReuseOrAllocNode
104 {
105 private:
106 using __node_alloc_type = _NodeAlloc;
107 using __hashtable_alloc = _Hashtable_alloc<__node_alloc_type>;
108 using __node_alloc_traits =
109 typename __hashtable_alloc::__node_alloc_traits;
110 using __node_type = typename __hashtable_alloc::__node_type;
111
112 public:
113 _ReuseOrAllocNode(__node_type* __nodes, __hashtable_alloc& __h)
114 : _M_nodes(__nodes), _M_h(__h) { }
115 _ReuseOrAllocNode(const _ReuseOrAllocNode&) = delete;
116
117 ~_ReuseOrAllocNode()
118 { _M_h._M_deallocate_nodes(_M_nodes); }
119
120 template<typename _Arg>
121 __node_type*
122 operator()(_Arg&& __arg) const
123 {
124 if (_M_nodes)
125 {
126 __node_type* __node = _M_nodes;
127 _M_nodes = _M_nodes->_M_next();
128 __node->_M_nxt = nullptr;
129 auto& __a = _M_h._M_node_allocator();
130 __node_alloc_traits::destroy(__a, __node->_M_valptr());
131 __try
132 {
133 __node_alloc_traits::construct(__a, __node->_M_valptr(),
134 std::forward<_Arg>(__arg));
135 }
136 __catch(...)
137 {
138 __node->~__node_type();
139 __node_alloc_traits::deallocate(__a, __node, 1);
140 __throw_exception_again;
141 }
142 return __node;
143 }
144 return _M_h._M_allocate_node(std::forward<_Arg>(__arg));
145 }
146
147 private:
148 mutable __node_type* _M_nodes;
149 __hashtable_alloc& _M_h;
150 };
151
152 // Functor similar to the previous one but without any pool of nodes to
153 // recycle.
154 template<typename _NodeAlloc>
155 struct _AllocNode
156 {
157 private:
158 using __hashtable_alloc = _Hashtable_alloc<_NodeAlloc>;
159 using __node_type = typename __hashtable_alloc::__node_type;
160
161 public:
162 _AllocNode(__hashtable_alloc& __h)
163 : _M_h(__h) { }
164
165 template<typename _Arg>
166 __node_type*
167 operator()(_Arg&& __arg) const
168 { return _M_h._M_allocate_node(std::forward<_Arg>(__arg)); }
169
170 private:
171 __hashtable_alloc& _M_h;
172 };
173
174 // Auxiliary types used for all instantiations of _Hashtable nodes
175 // and iterators.
176
177 /**
178 * struct _Hashtable_traits
179 *
180 * Important traits for hash tables.
181 *
182 * @tparam _Cache_hash_code Boolean value. True if the value of
183 * the hash function is stored along with the value. This is a
184 * time-space tradeoff. Storing it may improve lookup speed by
185 * reducing the number of times we need to call the _Equal
186 * function.
187 *
188 * @tparam _Constant_iterators Boolean value. True if iterator and
189 * const_iterator are both constant iterator types. This is true
190 * for unordered_set and unordered_multiset, false for
191 * unordered_map and unordered_multimap.
192 *
193 * @tparam _Unique_keys Boolean value. True if the return value
194 * of _Hashtable::count(k) is always at most one, false if it may
195 * be an arbitrary number. This is true for unordered_set and
196 * unordered_map, false for unordered_multiset and
197 * unordered_multimap.
198 */
199 template<bool _Cache_hash_code, bool _Constant_iterators, bool _Unique_keys>
200 struct _Hashtable_traits
201 {
202 using __hash_cached = __bool_constant<_Cache_hash_code>;
203 using __constant_iterators = __bool_constant<_Constant_iterators>;
204 using __unique_keys = __bool_constant<_Unique_keys>;
205 };
206
207 /**
208 * struct _Hash_node_base
209 *
210 * Nodes, used to wrap elements stored in the hash table. A policy
211 * template parameter of class template _Hashtable controls whether
212 * nodes also store a hash code. In some cases (e.g. strings) this
213 * may be a performance win.
214 */
215 struct _Hash_node_base
216 {
217 _Hash_node_base* _M_nxt;
218
219 _Hash_node_base() noexcept : _M_nxt() { }
220
221 _Hash_node_base(_Hash_node_base* __next) noexcept : _M_nxt(__next) { }
222 };
223
224 /**
225 * struct _Hash_node_value_base
226 *
227 * Node type with the value to store.
228 */
229 template<typename _Value>
230 struct _Hash_node_value_base : _Hash_node_base
231 {
232 typedef _Value value_type;
233
234 __gnu_cxx::__aligned_buffer<_Value> _M_storage;
235
236 _Value*
237 _M_valptr() noexcept
238 { return _M_storage._M_ptr(); }
239
240 const _Value*
241 _M_valptr() const noexcept
242 { return _M_storage._M_ptr(); }
243
244 _Value&
245 _M_v() noexcept
246 { return *_M_valptr(); }
247
248 const _Value&
249 _M_v() const noexcept
250 { return *_M_valptr(); }
251 };
252
253 /**
254 * Primary template struct _Hash_node.
255 */
256 template<typename _Value, bool _Cache_hash_code>
257 struct _Hash_node;
258
259 /**
260 * Specialization for nodes with caches, struct _Hash_node.
261 *
262 * Base class is __detail::_Hash_node_value_base.
263 */
264 template<typename _Value>
265 struct _Hash_node<_Value, true> : _Hash_node_value_base<_Value>
266 {
267 std::size_t _M_hash_code;
268
269 _Hash_node*
270 _M_next() const noexcept
271 { return static_cast<_Hash_node*>(this->_M_nxt); }
272 };
273
274 /**
275 * Specialization for nodes without caches, struct _Hash_node.
276 *
277 * Base class is __detail::_Hash_node_value_base.
278 */
279 template<typename _Value>
280 struct _Hash_node<_Value, false> : _Hash_node_value_base<_Value>
281 {
282 _Hash_node*
283 _M_next() const noexcept
284 { return static_cast<_Hash_node*>(this->_M_nxt); }
285 };
286
287 /// Base class for node iterators.
288 template<typename _Value, bool _Cache_hash_code>
289 struct _Node_iterator_base
290 {
291 using __node_type = _Hash_node<_Value, _Cache_hash_code>;
292
293 __node_type* _M_cur;
294
295 _Node_iterator_base(__node_type* __p) noexcept
296 : _M_cur(__p) { }
297
298 void
299 _M_incr() noexcept
300 { _M_cur = _M_cur->_M_next(); }
301 };
302
303 template<typename _Value, bool _Cache_hash_code>
304 inline bool
305 operator==(const _Node_iterator_base<_Value, _Cache_hash_code>& __x,
306 const _Node_iterator_base<_Value, _Cache_hash_code >& __y)
307 noexcept
308 { return __x._M_cur == __y._M_cur; }
309
310 template<typename _Value, bool _Cache_hash_code>
311 inline bool
312 operator!=(const _Node_iterator_base<_Value, _Cache_hash_code>& __x,
313 const _Node_iterator_base<_Value, _Cache_hash_code>& __y)
314 noexcept
315 { return __x._M_cur != __y._M_cur; }
316
317 /// Node iterators, used to iterate through all the hashtable.
318 template<typename _Value, bool __constant_iterators, bool __cache>
319 struct _Node_iterator
320 : public _Node_iterator_base<_Value, __cache>
321 {
322 private:
323 using __base_type = _Node_iterator_base<_Value, __cache>;
324 using __node_type = typename __base_type::__node_type;
325
326 public:
327 typedef _Value value_type;
328 typedef std::ptrdiff_t difference_type;
329 typedef std::forward_iterator_tag iterator_category;
330
331 using pointer = typename std::conditional<__constant_iterators,
332 const _Value*, _Value*>::type;
333
334 using reference = typename std::conditional<__constant_iterators,
335 const _Value&, _Value&>::type;
336
337 _Node_iterator() noexcept
338 : __base_type(0) { }
339
340 explicit
341 _Node_iterator(__node_type* __p) noexcept
342 : __base_type(__p) { }
343
344 reference
345 operator*() const noexcept
346 { return this->_M_cur->_M_v(); }
347
348 pointer
349 operator->() const noexcept
350 { return this->_M_cur->_M_valptr(); }
351
352 _Node_iterator&
353 operator++() noexcept
354 {
355 this->_M_incr();
356 return *this;
357 }
358
359 _Node_iterator
360 operator++(int) noexcept
361 {
362 _Node_iterator __tmp(*this);
363 this->_M_incr();
364 return __tmp;
365 }
366 };
367
368 /// Node const_iterators, used to iterate through all the hashtable.
369 template<typename _Value, bool __constant_iterators, bool __cache>
370 struct _Node_const_iterator
371 : public _Node_iterator_base<_Value, __cache>
372 {
373 private:
374 using __base_type = _Node_iterator_base<_Value, __cache>;
375 using __node_type = typename __base_type::__node_type;
376
377 public:
378 typedef _Value value_type;
379 typedef std::ptrdiff_t difference_type;
380 typedef std::forward_iterator_tag iterator_category;
381
382 typedef const _Value* pointer;
383 typedef const _Value& reference;
384
385 _Node_const_iterator() noexcept
386 : __base_type(0) { }
387
388 explicit
389 _Node_const_iterator(__node_type* __p) noexcept
390 : __base_type(__p) { }
391
392 _Node_const_iterator(const _Node_iterator<_Value, __constant_iterators,
393 __cache>& __x) noexcept
394 : __base_type(__x._M_cur) { }
395
396 reference
397 operator*() const noexcept
398 { return this->_M_cur->_M_v(); }
399
400 pointer
401 operator->() const noexcept
402 { return this->_M_cur->_M_valptr(); }
403
404 _Node_const_iterator&
405 operator++() noexcept
406 {
407 this->_M_incr();
408 return *this;
409 }
410
411 _Node_const_iterator
412 operator++(int) noexcept
413 {
414 _Node_const_iterator __tmp(*this);
415 this->_M_incr();
416 return __tmp;
417 }
418 };
419
420 // Many of class template _Hashtable's template parameters are policy
421 // classes. These are defaults for the policies.
422
423 /// Default range hashing function: use division to fold a large number
424 /// into the range [0, N).
425 struct _Mod_range_hashing
426 {
427 typedef std::size_t first_argument_type;
428 typedef std::size_t second_argument_type;
429 typedef std::size_t result_type;
430
431 result_type
432 operator()(first_argument_type __num,
433 second_argument_type __den) const noexcept
434 { return __num % __den; }
435 };
436
437 /// Default ranged hash function H. In principle it should be a
438 /// function object composed from objects of type H1 and H2 such that
439 /// h(k, N) = h2(h1(k), N), but that would mean making extra copies of
440 /// h1 and h2. So instead we'll just use a tag to tell class template
441 /// hashtable to do that composition.
442 struct _Default_ranged_hash { };
443
444 /// Default value for rehash policy. Bucket size is (usually) the
445 /// smallest prime that keeps the load factor small enough.
446 struct _Prime_rehash_policy
447 {
448 using __has_load_factor = std::true_type;
449
450 _Prime_rehash_policy(float __z = 1.0) noexcept
451 : _M_max_load_factor(__z), _M_next_resize(0) { }
452
453 float
454 max_load_factor() const noexcept
455 { return _M_max_load_factor; }
456
457 // Return a bucket size no smaller than n.
458 std::size_t
459 _M_next_bkt(std::size_t __n) const;
460
461 // Return a bucket count appropriate for n elements
462 std::size_t
463 _M_bkt_for_elements(std::size_t __n) const
464 { return __builtin_ceil(__n / (long double)_M_max_load_factor); }
465
466 // __n_bkt is current bucket count, __n_elt is current element count,
467 // and __n_ins is number of elements to be inserted. Do we need to
468 // increase bucket count? If so, return make_pair(true, n), where n
469 // is the new bucket count. If not, return make_pair(false, 0).
470 std::pair<bool, std::size_t>
471 _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt,
472 std::size_t __n_ins) const;
473
474 typedef std::size_t _State;
475
476 _State
477 _M_state() const
478 { return _M_next_resize; }
479
480 void
481 _M_reset() noexcept
482 { _M_next_resize = 0; }
483
484 void
485 _M_reset(_State __state)
486 { _M_next_resize = __state; }
487
488 static const std::size_t _S_growth_factor = 2;
489
490 float _M_max_load_factor;
491 mutable std::size_t _M_next_resize;
492 };
493
494 /// Range hashing function assuming that second arg is a power of 2.
495 struct _Mask_range_hashing
496 {
497 typedef std::size_t first_argument_type;
498 typedef std::size_t second_argument_type;
499 typedef std::size_t result_type;
500
501 result_type
502 operator()(first_argument_type __num,
503 second_argument_type __den) const noexcept
504 { return __num & (__den - 1); }
505 };
506
507 /// Compute closest power of 2.
508 _GLIBCXX14_CONSTEXPR
509 inline std::size_t
510 __clp2(std::size_t __n) noexcept
511 {
512#if __SIZEOF_SIZE_T__ >= 8
513 std::uint_fast64_t __x = __n;
514#else
515 std::uint_fast32_t __x = __n;
516#endif
517 // Algorithm from Hacker's Delight, Figure 3-3.
518 __x = __x - 1;
519 __x = __x | (__x >> 1);
520 __x = __x | (__x >> 2);
521 __x = __x | (__x >> 4);
522 __x = __x | (__x >> 8);
523 __x = __x | (__x >>16);
524#if __SIZEOF_SIZE_T__ >= 8
525 __x = __x | (__x >>32);
526#endif
527 return __x + 1;
528 }
529
530 /// Rehash policy providing power of 2 bucket numbers. Avoids modulo
531 /// operations.
532 struct _Power2_rehash_policy
533 {
534 using __has_load_factor = std::true_type;
535
536 _Power2_rehash_policy(float __z = 1.0) noexcept
537 : _M_max_load_factor(__z), _M_next_resize(0) { }
538
539 float
540 max_load_factor() const noexcept
541 { return _M_max_load_factor; }
542
543 // Return a bucket size no smaller than n (as long as n is not above the
544 // highest power of 2).
545 std::size_t
546 _M_next_bkt(std::size_t __n) noexcept
547 {
548 const auto __max_width = std::min<size_t>(sizeof(size_t), 8);
549 const auto __max_bkt = size_t(1) << (__max_width * __CHAR_BIT__ - 1);
550 std::size_t __res = __clp2(__n);
551
552 if (__res == __n)
553 __res <<= 1;
554
555 if (__res == 0)
556 __res = __max_bkt;
557
558 if (__res == __max_bkt)
559 // Set next resize to the max value so that we never try to rehash again
560 // as we already reach the biggest possible bucket number.
561 // Note that it might result in max_load_factor not being respected.
562 _M_next_resize = std::size_t(-1);
563 else
564 _M_next_resize
565 = __builtin_ceil(__res * (long double)_M_max_load_factor);
566
567 return __res;
568 }
569
570 // Return a bucket count appropriate for n elements
571 std::size_t
572 _M_bkt_for_elements(std::size_t __n) const noexcept
573 { return __builtin_ceil(__n / (long double)_M_max_load_factor); }
574
575 // __n_bkt is current bucket count, __n_elt is current element count,
576 // and __n_ins is number of elements to be inserted. Do we need to
577 // increase bucket count? If so, return make_pair(true, n), where n
578 // is the new bucket count. If not, return make_pair(false, 0).
579 std::pair<bool, std::size_t>
580 _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt,
581 std::size_t __n_ins) noexcept
582 {
583 if (__n_elt + __n_ins >= _M_next_resize)
584 {
585 long double __min_bkts = (__n_elt + __n_ins)
586 / (long double)_M_max_load_factor;
587 if (__min_bkts >= __n_bkt)
588 return std::make_pair(true,
589 _M_next_bkt(std::max<std::size_t>(__builtin_floor(__min_bkts) + 1,
590 __n_bkt * _S_growth_factor)));
591
592 _M_next_resize
593 = __builtin_floor(__n_bkt * (long double)_M_max_load_factor);
594 return std::make_pair(false, 0);
595 }
596 else
597 return std::make_pair(false, 0);
598 }
599
600 typedef std::size_t _State;
601
602 _State
603 _M_state() const noexcept
604 { return _M_next_resize; }
605
606 void
607 _M_reset() noexcept
608 { _M_next_resize = 0; }
609
610 void
611 _M_reset(_State __state) noexcept
612 { _M_next_resize = __state; }
613
614 static const std::size_t _S_growth_factor = 2;
615
616 float _M_max_load_factor;
617 std::size_t _M_next_resize;
618 };
619
620 // Base classes for std::_Hashtable. We define these base classes
621 // because in some cases we want to do different things depending on
622 // the value of a policy class. In some cases the policy class
623 // affects which member functions and nested typedefs are defined;
624 // we handle that by specializing base class templates. Several of
625 // the base class templates need to access other members of class
626 // template _Hashtable, so we use a variant of the "Curiously
627 // Recurring Template Pattern" (CRTP) technique.
628
629 /**
630 * Primary class template _Map_base.
631 *
632 * If the hashtable has a value type of the form pair<T1, T2> and a
633 * key extraction policy (_ExtractKey) that returns the first part
634 * of the pair, the hashtable gets a mapped_type typedef. If it
635 * satisfies those criteria and also has unique keys, then it also
636 * gets an operator[].
637 */
638 template<typename _Key, typename _Value, typename _Alloc,
639 typename _ExtractKey, typename _Equal,
640 typename _H1, typename _H2, typename _Hash,
641 typename _RehashPolicy, typename _Traits,
642 bool _Unique_keys = _Traits::__unique_keys::value>
643 struct _Map_base { };
644
645 /// Partial specialization, __unique_keys set to false.
646 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
647 typename _H1, typename _H2, typename _Hash,
648 typename _RehashPolicy, typename _Traits>
649 struct _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
650 _H1, _H2, _Hash, _RehashPolicy, _Traits, false>
651 {
652 using mapped_type = typename std::tuple_element<1, _Pair>::type;
653 };
654
655 /// Partial specialization, __unique_keys set to true.
656 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
657 typename _H1, typename _H2, typename _Hash,
658 typename _RehashPolicy, typename _Traits>
659 struct _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
660 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>
661 {
662 private:
663 using __hashtable_base = __detail::_Hashtable_base<_Key, _Pair,
664 _Select1st,
665 _Equal, _H1, _H2, _Hash,
666 _Traits>;
667
668 using __hashtable = _Hashtable<_Key, _Pair, _Alloc,
669 _Select1st, _Equal,
670 _H1, _H2, _Hash, _RehashPolicy, _Traits>;
671
672 using __hash_code = typename __hashtable_base::__hash_code;
673 using __node_type = typename __hashtable_base::__node_type;
674
675 public:
676 using key_type = typename __hashtable_base::key_type;
677 using iterator = typename __hashtable_base::iterator;
678 using mapped_type = typename std::tuple_element<1, _Pair>::type;
679
680 mapped_type&
681 operator[](const key_type& __k);
682
683 mapped_type&
684 operator[](key_type&& __k);
685
686 // _GLIBCXX_RESOLVE_LIB_DEFECTS
687 // DR 761. unordered_map needs an at() member function.
688 mapped_type&
689 at(const key_type& __k);
690
691 const mapped_type&
692 at(const key_type& __k) const;
693 };
694
695 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
696 typename _H1, typename _H2, typename _Hash,
697 typename _RehashPolicy, typename _Traits>
698 auto
699 _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
700 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
701 operator[](const key_type& __k)
702 -> mapped_type&
703 {
704 __hashtable* __h = static_cast<__hashtable*>(this);
705 __hash_code __code = __h->_M_hash_code(__k);
706 std::size_t __n = __h->_M_bucket_index(__k, __code);
707 __node_type* __p = __h->_M_find_node(__n, __k, __code);
708
709 if (!__p)
710 {
711 __p = __h->_M_allocate_node(std::piecewise_construct,
712 std::tuple<const key_type&>(__k),
713 std::tuple<>());
714 return __h->_M_insert_unique_node(__n, __code, __p)->second;
715 }
716
717 return __p->_M_v().second;
718 }
719
720 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
721 typename _H1, typename _H2, typename _Hash,
722 typename _RehashPolicy, typename _Traits>
723 auto
724 _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
725 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
726 operator[](key_type&& __k)
727 -> mapped_type&
728 {
729 __hashtable* __h = static_cast<__hashtable*>(this);
730 __hash_code __code = __h->_M_hash_code(__k);
731 std::size_t __n = __h->_M_bucket_index(__k, __code);
732 __node_type* __p = __h->_M_find_node(__n, __k, __code);
733
734 if (!__p)
735 {
736 __p = __h->_M_allocate_node(std::piecewise_construct,
737 std::forward_as_tuple(std::move(__k)),
738 std::tuple<>());
739 return __h->_M_insert_unique_node(__n, __code, __p)->second;
740 }
741
742 return __p->_M_v().second;
743 }
744
745 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
746 typename _H1, typename _H2, typename _Hash,
747 typename _RehashPolicy, typename _Traits>
748 auto
749 _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
750 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
751 at(const key_type& __k)
752 -> mapped_type&
753 {
754 __hashtable* __h = static_cast<__hashtable*>(this);
755 __hash_code __code = __h->_M_hash_code(__k);
756 std::size_t __n = __h->_M_bucket_index(__k, __code);
757 __node_type* __p = __h->_M_find_node(__n, __k, __code);
758
759 if (!__p)
760 __throw_out_of_range(__N("_Map_base::at"));
761 return __p->_M_v().second;
762 }
763
764 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
765 typename _H1, typename _H2, typename _Hash,
766 typename _RehashPolicy, typename _Traits>
767 auto
768 _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
769 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
770 at(const key_type& __k) const
771 -> const mapped_type&
772 {
773 const __hashtable* __h = static_cast<const __hashtable*>(this);
774 __hash_code __code = __h->_M_hash_code(__k);
775 std::size_t __n = __h->_M_bucket_index(__k, __code);
776 __node_type* __p = __h->_M_find_node(__n, __k, __code);
777
778 if (!__p)
779 __throw_out_of_range(__N("_Map_base::at"));
780 return __p->_M_v().second;
781 }
782
783 /**
784 * Primary class template _Insert_base.
785 *
786 * Defines @c insert member functions appropriate to all _Hashtables.
787 */
788 template<typename _Key, typename _Value, typename _Alloc,
789 typename _ExtractKey, typename _Equal,
790 typename _H1, typename _H2, typename _Hash,
791 typename _RehashPolicy, typename _Traits>
792 struct _Insert_base
793 {
794 protected:
795 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey,
796 _Equal, _H1, _H2, _Hash,
797 _RehashPolicy, _Traits>;
798
799 using __hashtable_base = _Hashtable_base<_Key, _Value, _ExtractKey,
800 _Equal, _H1, _H2, _Hash,
801 _Traits>;
802
803 using value_type = typename __hashtable_base::value_type;
804 using iterator = typename __hashtable_base::iterator;
805 using const_iterator = typename __hashtable_base::const_iterator;
806 using size_type = typename __hashtable_base::size_type;
807
808 using __unique_keys = typename __hashtable_base::__unique_keys;
809 using __ireturn_type = typename __hashtable_base::__ireturn_type;
810 using __node_type = _Hash_node<_Value, _Traits::__hash_cached::value>;
811 using __node_alloc_type = __alloc_rebind<_Alloc, __node_type>;
812 using __node_gen_type = _AllocNode<__node_alloc_type>;
813
814 __hashtable&
815 _M_conjure_hashtable()
816 { return *(static_cast<__hashtable*>(this)); }
817
818 template<typename _InputIterator, typename _NodeGetter>
819 void
820 _M_insert_range(_InputIterator __first, _InputIterator __last,
821 const _NodeGetter&, true_type);
822
823 template<typename _InputIterator, typename _NodeGetter>
824 void
825 _M_insert_range(_InputIterator __first, _InputIterator __last,
826 const _NodeGetter&, false_type);
827
828 public:
829 __ireturn_type
830 insert(const value_type& __v)
831 {
832 __hashtable& __h = _M_conjure_hashtable();
833 __node_gen_type __node_gen(__h);
834 return __h._M_insert(__v, __node_gen, __unique_keys());
835 }
836
837 iterator
838 insert(const_iterator __hint, const value_type& __v)
839 {
840 __hashtable& __h = _M_conjure_hashtable();
841 __node_gen_type __node_gen(__h);
842 return __h._M_insert(__hint, __v, __node_gen, __unique_keys());
843 }
844
845 void
846 insert(initializer_list<value_type> __l)
847 { this->insert(__l.begin(), __l.end()); }
848
849 template<typename _InputIterator>
850 void
851 insert(_InputIterator __first, _InputIterator __last)
852 {
853 __hashtable& __h = _M_conjure_hashtable();
854 __node_gen_type __node_gen(__h);
855 return _M_insert_range(__first, __last, __node_gen, __unique_keys());
856 }
857 };
858
859 template<typename _Key, typename _Value, typename _Alloc,
860 typename _ExtractKey, typename _Equal,
861 typename _H1, typename _H2, typename _Hash,
862 typename _RehashPolicy, typename _Traits>
863 template<typename _InputIterator, typename _NodeGetter>
864 void
865 _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
866 _RehashPolicy, _Traits>::
867 _M_insert_range(_InputIterator __first, _InputIterator __last,
868 const _NodeGetter& __node_gen, true_type)
869 {
870 size_type __n_elt = __detail::__distance_fw(__first, __last);
871 if (__n_elt == 0)
872 return;
873
874 __hashtable& __h = _M_conjure_hashtable();
875 for (; __first != __last; ++__first)
876 {
877 if (__h._M_insert(*__first, __node_gen, __unique_keys(),
878 __n_elt).second)
879 __n_elt = 1;
880 else if (__n_elt != 1)
881 --__n_elt;
882 }
883 }
884
885 template<typename _Key, typename _Value, typename _Alloc,
886 typename _ExtractKey, typename _Equal,
887 typename _H1, typename _H2, typename _Hash,
888 typename _RehashPolicy, typename _Traits>
889 template<typename _InputIterator, typename _NodeGetter>
890 void
891 _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
892 _RehashPolicy, _Traits>::
893 _M_insert_range(_InputIterator __first, _InputIterator __last,
894 const _NodeGetter& __node_gen, false_type)
895 {
896 using __rehash_type = typename __hashtable::__rehash_type;
897 using __rehash_state = typename __hashtable::__rehash_state;
898 using pair_type = std::pair<bool, std::size_t>;
899
900 size_type __n_elt = __detail::__distance_fw(__first, __last);
901 if (__n_elt == 0)
902 return;
903
904 __hashtable& __h = _M_conjure_hashtable();
905 __rehash_type& __rehash = __h._M_rehash_policy;
906 const __rehash_state& __saved_state = __rehash._M_state();
907 pair_type __do_rehash = __rehash._M_need_rehash(__h._M_bucket_count,
908 __h._M_element_count,
909 __n_elt);
910
911 if (__do_rehash.first)
912 __h._M_rehash(__do_rehash.second, __saved_state);
913
914 for (; __first != __last; ++__first)
915 __h._M_insert(*__first, __node_gen, __unique_keys());
916 }
917
918 /**
919 * Primary class template _Insert.
920 *
921 * Defines @c insert member functions that depend on _Hashtable policies,
922 * via partial specializations.
923 */
924 template<typename _Key, typename _Value, typename _Alloc,
925 typename _ExtractKey, typename _Equal,
926 typename _H1, typename _H2, typename _Hash,
927 typename _RehashPolicy, typename _Traits,
928 bool _Constant_iterators = _Traits::__constant_iterators::value>
929 struct _Insert;
930
931 /// Specialization.
932 template<typename _Key, typename _Value, typename _Alloc,
933 typename _ExtractKey, typename _Equal,
934 typename _H1, typename _H2, typename _Hash,
935 typename _RehashPolicy, typename _Traits>
936 struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
937 _RehashPolicy, _Traits, true>
938 : public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
939 _H1, _H2, _Hash, _RehashPolicy, _Traits>
940 {
941 using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey,
942 _Equal, _H1, _H2, _Hash,
943 _RehashPolicy, _Traits>;
944
945 using __hashtable_base = _Hashtable_base<_Key, _Value, _ExtractKey,
946 _Equal, _H1, _H2, _Hash,
947 _Traits>;
948
949 using value_type = typename __base_type::value_type;
950 using iterator = typename __base_type::iterator;
951 using const_iterator = typename __base_type::const_iterator;
952
953 using __unique_keys = typename __base_type::__unique_keys;
954 using __ireturn_type = typename __hashtable_base::__ireturn_type;
955 using __hashtable = typename __base_type::__hashtable;
956 using __node_gen_type = typename __base_type::__node_gen_type;
957
958 using __base_type::insert;
959
960 __ireturn_type
961 insert(value_type&& __v)
962 {
963 __hashtable& __h = this->_M_conjure_hashtable();
964 __node_gen_type __node_gen(__h);
965 return __h._M_insert(std::move(__v), __node_gen, __unique_keys());
966 }
967
968 iterator
969 insert(const_iterator __hint, value_type&& __v)
970 {
971 __hashtable& __h = this->_M_conjure_hashtable();
972 __node_gen_type __node_gen(__h);
973 return __h._M_insert(__hint, std::move(__v), __node_gen,
974 __unique_keys());
975 }
976 };
977
978 /// Specialization.
979 template<typename _Key, typename _Value, typename _Alloc,
980 typename _ExtractKey, typename _Equal,
981 typename _H1, typename _H2, typename _Hash,
982 typename _RehashPolicy, typename _Traits>
983 struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
984 _RehashPolicy, _Traits, false>
985 : public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
986 _H1, _H2, _Hash, _RehashPolicy, _Traits>
987 {
988 using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey,
989 _Equal, _H1, _H2, _Hash,
990 _RehashPolicy, _Traits>;
991 using value_type = typename __base_type::value_type;
992 using iterator = typename __base_type::iterator;
993 using const_iterator = typename __base_type::const_iterator;
994
995 using __unique_keys = typename __base_type::__unique_keys;
996 using __hashtable = typename __base_type::__hashtable;
997 using __ireturn_type = typename __base_type::__ireturn_type;
998
999 using __base_type::insert;
1000
1001 template<typename _Pair>
1002 using __is_cons = std::is_constructible<value_type, _Pair&&>;
1003
1004 template<typename _Pair>
1005 using _IFcons = std::enable_if<__is_cons<_Pair>::value>;
1006
1007 template<typename _Pair>
1008 using _IFconsp = typename _IFcons<_Pair>::type;
1009
1010 template<typename _Pair, typename = _IFconsp<_Pair>>
1011 __ireturn_type
1012 insert(_Pair&& __v)
1013 {
1014 __hashtable& __h = this->_M_conjure_hashtable();
1015 return __h._M_emplace(__unique_keys(), std::forward<_Pair>(__v));
1016 }
1017
1018 template<typename _Pair, typename = _IFconsp<_Pair>>
1019 iterator
1020 insert(const_iterator __hint, _Pair&& __v)
1021 {
1022 __hashtable& __h = this->_M_conjure_hashtable();
1023 return __h._M_emplace(__hint, __unique_keys(),
1024 std::forward<_Pair>(__v));
1025 }
1026 };
1027
1028 template<typename _Policy>
1029 using __has_load_factor = typename _Policy::__has_load_factor;
1030
1031 /**
1032 * Primary class template _Rehash_base.
1033 *
1034 * Give hashtable the max_load_factor functions and reserve iff the
1035 * rehash policy supports it.
1036 */
1037 template<typename _Key, typename _Value, typename _Alloc,
1038 typename _ExtractKey, typename _Equal,
1039 typename _H1, typename _H2, typename _Hash,
1040 typename _RehashPolicy, typename _Traits,
1041 typename =
1042 __detected_or_t<std::false_type, __has_load_factor, _RehashPolicy>>
1043 struct _Rehash_base;
1044
1045 /// Specialization when rehash policy doesn't provide load factor management.
1046 template<typename _Key, typename _Value, typename _Alloc,
1047 typename _ExtractKey, typename _Equal,
1048 typename _H1, typename _H2, typename _Hash,
1049 typename _RehashPolicy, typename _Traits>
1050 struct _Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1051 _H1, _H2, _Hash, _RehashPolicy, _Traits,
1052 std::false_type>
1053 {
1054 };
1055
1056 /// Specialization when rehash policy provide load factor management.
1057 template<typename _Key, typename _Value, typename _Alloc,
1058 typename _ExtractKey, typename _Equal,
1059 typename _H1, typename _H2, typename _Hash,
1060 typename _RehashPolicy, typename _Traits>
1061 struct _Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1062 _H1, _H2, _Hash, _RehashPolicy, _Traits,
1063 std::true_type>
1064 {
1065 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey,
1066 _Equal, _H1, _H2, _Hash,
1067 _RehashPolicy, _Traits>;
1068
1069 float
1070 max_load_factor() const noexcept
1071 {
1072 const __hashtable* __this = static_cast<const __hashtable*>(this);
1073 return __this->__rehash_policy().max_load_factor();
1074 }
1075
1076 void
1077 max_load_factor(float __z)
1078 {
1079 __hashtable* __this = static_cast<__hashtable*>(this);
1080 __this->__rehash_policy(_RehashPolicy(__z));
1081 }
1082
1083 void
1084 reserve(std::size_t __n)
1085 {
1086 __hashtable* __this = static_cast<__hashtable*>(this);
1087 __this->rehash(__builtin_ceil(__n / max_load_factor()));
1088 }
1089 };
1090
1091 /**
1092 * Primary class template _Hashtable_ebo_helper.
1093 *
1094 * Helper class using EBO when it is not forbidden (the type is not
1095 * final) and when it is worth it (the type is empty.)
1096 */
1097 template<int _Nm, typename _Tp,
1098 bool __use_ebo = !__is_final(_Tp) && __is_empty(_Tp)>
1099 struct _Hashtable_ebo_helper;
1100
1101 /// Specialization using EBO.
1102 template<int _Nm, typename _Tp>
1103 struct _Hashtable_ebo_helper<_Nm, _Tp, true>
1104 : private _Tp
1105 {
1106 _Hashtable_ebo_helper() = default;
1107
1108 template<typename _OtherTp>
1109 _Hashtable_ebo_helper(_OtherTp&& __tp)
1110 : _Tp(std::forward<_OtherTp>(__tp))
1111 { }
1112
1113 static const _Tp&
1114 _S_cget(const _Hashtable_ebo_helper& __eboh)
1115 { return static_cast<const _Tp&>(__eboh); }
1116
1117 static _Tp&
1118 _S_get(_Hashtable_ebo_helper& __eboh)
1119 { return static_cast<_Tp&>(__eboh); }
1120 };
1121
1122 /// Specialization not using EBO.
1123 template<int _Nm, typename _Tp>
1124 struct _Hashtable_ebo_helper<_Nm, _Tp, false>
1125 {
1126 _Hashtable_ebo_helper() = default;
1127
1128 template<typename _OtherTp>
1129 _Hashtable_ebo_helper(_OtherTp&& __tp)
1130 : _M_tp(std::forward<_OtherTp>(__tp))
1131 { }
1132
1133 static const _Tp&
1134 _S_cget(const _Hashtable_ebo_helper& __eboh)
1135 { return __eboh._M_tp; }
1136
1137 static _Tp&
1138 _S_get(_Hashtable_ebo_helper& __eboh)
1139 { return __eboh._M_tp; }
1140
1141 private:
1142 _Tp _M_tp;
1143 };
1144
1145 /**
1146 * Primary class template _Local_iterator_base.
1147 *
1148 * Base class for local iterators, used to iterate within a bucket
1149 * but not between buckets.
1150 */
1151 template<typename _Key, typename _Value, typename _ExtractKey,
1152 typename _H1, typename _H2, typename _Hash,
1153 bool __cache_hash_code>
1154 struct _Local_iterator_base;
1155
1156 /**
1157 * Primary class template _Hash_code_base.
1158 *
1159 * Encapsulates two policy issues that aren't quite orthogonal.
1160 * (1) the difference between using a ranged hash function and using
1161 * the combination of a hash function and a range-hashing function.
1162 * In the former case we don't have such things as hash codes, so
1163 * we have a dummy type as placeholder.
1164 * (2) Whether or not we cache hash codes. Caching hash codes is
1165 * meaningless if we have a ranged hash function.
1166 *
1167 * We also put the key extraction objects here, for convenience.
1168 * Each specialization derives from one or more of the template
1169 * parameters to benefit from Ebo. This is important as this type
1170 * is inherited in some cases by the _Local_iterator_base type used
1171 * to implement local_iterator and const_local_iterator. As with
1172 * any iterator type we prefer to make it as small as possible.
1173 *
1174 * Primary template is unused except as a hook for specializations.
1175 */
1176 template<typename _Key, typename _Value, typename _ExtractKey,
1177 typename _H1, typename _H2, typename _Hash,
1178 bool __cache_hash_code>
1179 struct _Hash_code_base;
1180
1181 /// Specialization: ranged hash function, no caching hash codes. H1
1182 /// and H2 are provided but ignored. We define a dummy hash code type.
1183 template<typename _Key, typename _Value, typename _ExtractKey,
1184 typename _H1, typename _H2, typename _Hash>
1185 struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>
1186 : private _Hashtable_ebo_helper<0, _ExtractKey>,
1187 private _Hashtable_ebo_helper<1, _Hash>
1188 {
1189 private:
1190 using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>;
1191 using __ebo_hash = _Hashtable_ebo_helper<1, _Hash>;
1192
1193 protected:
1194 typedef void* __hash_code;
1195 typedef _Hash_node<_Value, false> __node_type;
1196
1197 // We need the default constructor for the local iterators and _Hashtable
1198 // default constructor.
1199 _Hash_code_base() = default;
1200
1201 _Hash_code_base(const _ExtractKey& __ex, const _H1&, const _H2&,
1202 const _Hash& __h)
1203 : __ebo_extract_key(__ex), __ebo_hash(__h) { }
1204
1205 __hash_code
1206 _M_hash_code(const _Key& __key) const
1207 { return 0; }
1208
1209 std::size_t
1210 _M_bucket_index(const _Key& __k, __hash_code, std::size_t __n) const
1211 { return _M_ranged_hash()(__k, __n); }
1212
1213 std::size_t
1214 _M_bucket_index(const __node_type* __p, std::size_t __n) const
1215 noexcept( noexcept(declval<const _Hash&>()(declval<const _Key&>(),
1216 (std::size_t)0)) )
1217 { return _M_ranged_hash()(_M_extract()(__p->_M_v()), __n); }
1218
1219 void
1220 _M_store_code(__node_type*, __hash_code) const
1221 { }
1222
1223 void
1224 _M_copy_code(__node_type*, const __node_type*) const
1225 { }
1226
1227 void
1228 _M_swap(_Hash_code_base& __x)
1229 {
1230 std::swap(_M_extract(), __x._M_extract());
1231 std::swap(_M_ranged_hash(), __x._M_ranged_hash());
1232 }
1233
1234 const _ExtractKey&
1235 _M_extract() const { return __ebo_extract_key::_S_cget(*this); }
1236
1237 _ExtractKey&
1238 _M_extract() { return __ebo_extract_key::_S_get(*this); }
1239
1240 const _Hash&
1241 _M_ranged_hash() const { return __ebo_hash::_S_cget(*this); }
1242
1243 _Hash&
1244 _M_ranged_hash() { return __ebo_hash::_S_get(*this); }
1245 };
1246
1247 // No specialization for ranged hash function while caching hash codes.
1248 // That combination is meaningless, and trying to do it is an error.
1249
1250 /// Specialization: ranged hash function, cache hash codes. This
1251 /// combination is meaningless, so we provide only a declaration
1252 /// and no definition.
1253 template<typename _Key, typename _Value, typename _ExtractKey,
1254 typename _H1, typename _H2, typename _Hash>
1255 struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, true>;
1256
1257 /// Specialization: hash function and range-hashing function, no
1258 /// caching of hash codes.
1259 /// Provides typedef and accessor required by C++ 11.
1260 template<typename _Key, typename _Value, typename _ExtractKey,
1261 typename _H1, typename _H2>
1262 struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2,
1263 _Default_ranged_hash, false>
1264 : private _Hashtable_ebo_helper<0, _ExtractKey>,
1265 private _Hashtable_ebo_helper<1, _H1>,
1266 private _Hashtable_ebo_helper<2, _H2>
1267 {
1268 private:
1269 using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>;
1270 using __ebo_h1 = _Hashtable_ebo_helper<1, _H1>;
1271 using __ebo_h2 = _Hashtable_ebo_helper<2, _H2>;
1272
1273 // Gives the local iterator implementation access to _M_bucket_index().
1274 friend struct _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2,
1275 _Default_ranged_hash, false>;
1276
1277 public:
1278 typedef _H1 hasher;
1279
1280 hasher
1281 hash_function() const
1282 { return _M_h1(); }
1283
1284 protected:
1285 typedef std::size_t __hash_code;
1286 typedef _Hash_node<_Value, false> __node_type;
1287
1288 // We need the default constructor for the local iterators and _Hashtable
1289 // default constructor.
1290 _Hash_code_base() = default;
1291
1292 _Hash_code_base(const _ExtractKey& __ex,
1293 const _H1& __h1, const _H2& __h2,
1294 const _Default_ranged_hash&)
1295 : __ebo_extract_key(__ex), __ebo_h1(__h1), __ebo_h2(__h2) { }
1296
1297 __hash_code
1298 _M_hash_code(const _Key& __k) const
1299 { return _M_h1()(__k); }
1300
1301 std::size_t
1302 _M_bucket_index(const _Key&, __hash_code __c, std::size_t __n) const
1303 { return _M_h2()(__c, __n); }
1304
1305 std::size_t
1306 _M_bucket_index(const __node_type* __p, std::size_t __n) const
1307 noexcept( noexcept(declval<const _H1&>()(declval<const _Key&>()))
1308 && noexcept(declval<const _H2&>()((__hash_code)0,
1309 (std::size_t)0)) )
1310 { return _M_h2()(_M_h1()(_M_extract()(__p->_M_v())), __n); }
1311
1312 void
1313 _M_store_code(__node_type*, __hash_code) const
1314 { }
1315
1316 void
1317 _M_copy_code(__node_type*, const __node_type*) const
1318 { }
1319
1320 void
1321 _M_swap(_Hash_code_base& __x)
1322 {
1323 std::swap(_M_extract(), __x._M_extract());
1324 std::swap(_M_h1(), __x._M_h1());
1325 std::swap(_M_h2(), __x._M_h2());
1326 }
1327
1328 const _ExtractKey&
1329 _M_extract() const { return __ebo_extract_key::_S_cget(*this); }
1330
1331 _ExtractKey&
1332 _M_extract() { return __ebo_extract_key::_S_get(*this); }
1333
1334 const _H1&
1335 _M_h1() const { return __ebo_h1::_S_cget(*this); }
1336
1337 _H1&
1338 _M_h1() { return __ebo_h1::_S_get(*this); }
1339
1340 const _H2&
1341 _M_h2() const { return __ebo_h2::_S_cget(*this); }
1342
1343 _H2&
1344 _M_h2() { return __ebo_h2::_S_get(*this); }
1345 };
1346
1347 /// Specialization: hash function and range-hashing function,
1348 /// caching hash codes. H is provided but ignored. Provides
1349 /// typedef and accessor required by C++ 11.
1350 template<typename _Key, typename _Value, typename _ExtractKey,
1351 typename _H1, typename _H2>
1352 struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2,
1353 _Default_ranged_hash, true>
1354 : private _Hashtable_ebo_helper<0, _ExtractKey>,
1355 private _Hashtable_ebo_helper<1, _H1>,
1356 private _Hashtable_ebo_helper<2, _H2>
1357 {
1358 private:
1359 // Gives the local iterator implementation access to _M_h2().
1360 friend struct _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2,
1361 _Default_ranged_hash, true>;
1362
1363 using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>;
1364 using __ebo_h1 = _Hashtable_ebo_helper<1, _H1>;
1365 using __ebo_h2 = _Hashtable_ebo_helper<2, _H2>;
1366
1367 public:
1368 typedef _H1 hasher;
1369
1370 hasher
1371 hash_function() const
1372 { return _M_h1(); }
1373
1374 protected:
1375 typedef std::size_t __hash_code;
1376 typedef _Hash_node<_Value, true> __node_type;
1377
1378 // We need the default constructor for _Hashtable default constructor.
1379 _Hash_code_base() = default;
1380 _Hash_code_base(const _ExtractKey& __ex,
1381 const _H1& __h1, const _H2& __h2,
1382 const _Default_ranged_hash&)
1383 : __ebo_extract_key(__ex), __ebo_h1(__h1), __ebo_h2(__h2) { }
1384
1385 __hash_code
1386 _M_hash_code(const _Key& __k) const
1387 { return _M_h1()(__k); }
1388
1389 std::size_t
1390 _M_bucket_index(const _Key&, __hash_code __c,
1391 std::size_t __n) const
1392 { return _M_h2()(__c, __n); }
1393
1394 std::size_t
1395 _M_bucket_index(const __node_type* __p, std::size_t __n) const
1396 noexcept( noexcept(declval<const _H2&>()((__hash_code)0,
1397 (std::size_t)0)) )
1398 { return _M_h2()(__p->_M_hash_code, __n); }
1399
1400 void
1401 _M_store_code(__node_type* __n, __hash_code __c) const
1402 { __n->_M_hash_code = __c; }
1403
1404 void
1405 _M_copy_code(__node_type* __to, const __node_type* __from) const
1406 { __to->_M_hash_code = __from->_M_hash_code; }
1407
1408 void
1409 _M_swap(_Hash_code_base& __x)
1410 {
1411 std::swap(_M_extract(), __x._M_extract());
1412 std::swap(_M_h1(), __x._M_h1());
1413 std::swap(_M_h2(), __x._M_h2());
1414 }
1415
1416 const _ExtractKey&
1417 _M_extract() const { return __ebo_extract_key::_S_cget(*this); }
1418
1419 _ExtractKey&
1420 _M_extract() { return __ebo_extract_key::_S_get(*this); }
1421
1422 const _H1&
1423 _M_h1() const { return __ebo_h1::_S_cget(*this); }
1424
1425 _H1&
1426 _M_h1() { return __ebo_h1::_S_get(*this); }
1427
1428 const _H2&
1429 _M_h2() const { return __ebo_h2::_S_cget(*this); }
1430
1431 _H2&
1432 _M_h2() { return __ebo_h2::_S_get(*this); }
1433 };
1434
1435 /**
1436 * Primary class template _Equal_helper.
1437 *
1438 */
1439 template <typename _Key, typename _Value, typename _ExtractKey,
1440 typename _Equal, typename _HashCodeType,
1441 bool __cache_hash_code>
1442 struct _Equal_helper;
1443
1444 /// Specialization.
1445 template<typename _Key, typename _Value, typename _ExtractKey,
1446 typename _Equal, typename _HashCodeType>
1447 struct _Equal_helper<_Key, _Value, _ExtractKey, _Equal, _HashCodeType, true>
1448 {
1449 static bool
1450 _S_equals(const _Equal& __eq, const _ExtractKey& __extract,
1451 const _Key& __k, _HashCodeType __c, _Hash_node<_Value, true>* __n)
1452 { return __c == __n->_M_hash_code && __eq(__k, __extract(__n->_M_v())); }
1453 };
1454
1455 /// Specialization.
1456 template<typename _Key, typename _Value, typename _ExtractKey,
1457 typename _Equal, typename _HashCodeType>
1458 struct _Equal_helper<_Key, _Value, _ExtractKey, _Equal, _HashCodeType, false>
1459 {
1460 static bool
1461 _S_equals(const _Equal& __eq, const _ExtractKey& __extract,
1462 const _Key& __k, _HashCodeType, _Hash_node<_Value, false>* __n)
1463 { return __eq(__k, __extract(__n->_M_v())); }
1464 };
1465
1466
1467 /// Partial specialization used when nodes contain a cached hash code.
1468 template<typename _Key, typename _Value, typename _ExtractKey,
1469 typename _H1, typename _H2, typename _Hash>
1470 struct _Local_iterator_base<_Key, _Value, _ExtractKey,
1471 _H1, _H2, _Hash, true>
1472 : private _Hashtable_ebo_helper<0, _H2>
1473 {
1474 protected:
1475 using __base_type = _Hashtable_ebo_helper<0, _H2>;
1476 using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey,
1477 _H1, _H2, _Hash, true>;
1478
1479 _Local_iterator_base() = default;
1480 _Local_iterator_base(const __hash_code_base& __base,
1481 _Hash_node<_Value, true>* __p,
1482 std::size_t __bkt, std::size_t __bkt_count)
1483 : __base_type(__base._M_h2()),
1484 _M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count) { }
1485
1486 void
1487 _M_incr()
1488 {
1489 _M_cur = _M_cur->_M_next();
1490 if (_M_cur)
1491 {
1492 std::size_t __bkt
1493 = __base_type::_S_get(*this)(_M_cur->_M_hash_code,
1494 _M_bucket_count);
1495 if (__bkt != _M_bucket)
1496 _M_cur = nullptr;
1497 }
1498 }
1499
1500 _Hash_node<_Value, true>* _M_cur;
1501 std::size_t _M_bucket;
1502 std::size_t _M_bucket_count;
1503
1504 public:
1505 const void*
1506 _M_curr() const { return _M_cur; } // for equality ops
1507
1508 std::size_t
1509 _M_get_bucket() const { return _M_bucket; } // for debug mode
1510 };
1511
1512 // Uninitialized storage for a _Hash_code_base.
1513 // This type is DefaultConstructible and Assignable even if the
1514 // _Hash_code_base type isn't, so that _Local_iterator_base<..., false>
1515 // can be DefaultConstructible and Assignable.
1516 template<typename _Tp, bool _IsEmpty = std::is_empty<_Tp>::value>
1517 struct _Hash_code_storage
1518 {
1519 __gnu_cxx::__aligned_buffer<_Tp> _M_storage;
1520
1521 _Tp*
1522 _M_h() { return _M_storage._M_ptr(); }
1523
1524 const _Tp*
1525 _M_h() const { return _M_storage._M_ptr(); }
1526 };
1527
1528 // Empty partial specialization for empty _Hash_code_base types.
1529 template<typename _Tp>
1530 struct _Hash_code_storage<_Tp, true>
1531 {
1532 static_assert( std::is_empty<_Tp>::value, "Type must be empty" );
1533
1534 // As _Tp is an empty type there will be no bytes written/read through
1535 // the cast pointer, so no strict-aliasing violation.
1536 _Tp*
1537 _M_h() { return reinterpret_cast<_Tp*>(this); }
1538
1539 const _Tp*
1540 _M_h() const { return reinterpret_cast<const _Tp*>(this); }
1541 };
1542
1543 template<typename _Key, typename _Value, typename _ExtractKey,
1544 typename _H1, typename _H2, typename _Hash>
1545 using __hash_code_for_local_iter
1546 = _Hash_code_storage<_Hash_code_base<_Key, _Value, _ExtractKey,
1547 _H1, _H2, _Hash, false>>;
1548
1549 // Partial specialization used when hash codes are not cached
1550 template<typename _Key, typename _Value, typename _ExtractKey,
1551 typename _H1, typename _H2, typename _Hash>
1552 struct _Local_iterator_base<_Key, _Value, _ExtractKey,
1553 _H1, _H2, _Hash, false>
1554 : __hash_code_for_local_iter<_Key, _Value, _ExtractKey, _H1, _H2, _Hash>
1555 {
1556 protected:
1557 using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey,
1558 _H1, _H2, _Hash, false>;
1559
1560 _Local_iterator_base() : _M_bucket_count(-1) { }
1561
1562 _Local_iterator_base(const __hash_code_base& __base,
1563 _Hash_node<_Value, false>* __p,
1564 std::size_t __bkt, std::size_t __bkt_count)
1565 : _M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count)
1566 { _M_init(__base); }
1567
1568 ~_Local_iterator_base()
1569 {
1570 if (_M_bucket_count != -1)
1571 _M_destroy();
1572 }
1573
1574 _Local_iterator_base(const _Local_iterator_base& __iter)
1575 : _M_cur(__iter._M_cur), _M_bucket(__iter._M_bucket),
1576 _M_bucket_count(__iter._M_bucket_count)
1577 {
1578 if (_M_bucket_count != -1)
1579 _M_init(*__iter._M_h());
1580 }
1581
1582 _Local_iterator_base&
1583 operator=(const _Local_iterator_base& __iter)
1584 {
1585 if (_M_bucket_count != -1)
1586 _M_destroy();
1587 _M_cur = __iter._M_cur;
1588 _M_bucket = __iter._M_bucket;
1589 _M_bucket_count = __iter._M_bucket_count;
1590 if (_M_bucket_count != -1)
1591 _M_init(*__iter._M_h());
1592 return *this;
1593 }
1594
1595 void
1596 _M_incr()
1597 {
1598 _M_cur = _M_cur->_M_next();
1599 if (_M_cur)
1600 {
1601 std::size_t __bkt = this->_M_h()->_M_bucket_index(_M_cur,
1602 _M_bucket_count);
1603 if (__bkt != _M_bucket)
1604 _M_cur = nullptr;
1605 }
1606 }
1607
1608 _Hash_node<_Value, false>* _M_cur;
1609 std::size_t _M_bucket;
1610 std::size_t _M_bucket_count;
1611
1612 void
1613 _M_init(const __hash_code_base& __base)
1614 { ::new(this->_M_h()) __hash_code_base(__base); }
1615
1616 void
1617 _M_destroy() { this->_M_h()->~__hash_code_base(); }
1618
1619 public:
1620 const void*
1621 _M_curr() const { return _M_cur; } // for equality ops and debug mode
1622
1623 std::size_t
1624 _M_get_bucket() const { return _M_bucket; } // for debug mode
1625 };
1626
1627 template<typename _Key, typename _Value, typename _ExtractKey,
1628 typename _H1, typename _H2, typename _Hash, bool __cache>
1629 inline bool
1630 operator==(const _Local_iterator_base<_Key, _Value, _ExtractKey,
1631 _H1, _H2, _Hash, __cache>& __x,
1632 const _Local_iterator_base<_Key, _Value, _ExtractKey,
1633 _H1, _H2, _Hash, __cache>& __y)
1634 { return __x._M_curr() == __y._M_curr(); }
1635
1636 template<typename _Key, typename _Value, typename _ExtractKey,
1637 typename _H1, typename _H2, typename _Hash, bool __cache>
1638 inline bool
1639 operator!=(const _Local_iterator_base<_Key, _Value, _ExtractKey,
1640 _H1, _H2, _Hash, __cache>& __x,
1641 const _Local_iterator_base<_Key, _Value, _ExtractKey,
1642 _H1, _H2, _Hash, __cache>& __y)
1643 { return __x._M_curr() != __y._M_curr(); }
1644
1645 /// local iterators
1646 template<typename _Key, typename _Value, typename _ExtractKey,
1647 typename _H1, typename _H2, typename _Hash,
1648 bool __constant_iterators, bool __cache>
1649 struct _Local_iterator
1650 : public _Local_iterator_base<_Key, _Value, _ExtractKey,
1651 _H1, _H2, _Hash, __cache>
1652 {
1653 private:
1654 using __base_type = _Local_iterator_base<_Key, _Value, _ExtractKey,
1655 _H1, _H2, _Hash, __cache>;
1656 using __hash_code_base = typename __base_type::__hash_code_base;
1657 public:
1658 typedef _Value value_type;
1659 typedef typename std::conditional<__constant_iterators,
1660 const _Value*, _Value*>::type
1661 pointer;
1662 typedef typename std::conditional<__constant_iterators,
1663 const _Value&, _Value&>::type
1664 reference;
1665 typedef std::ptrdiff_t difference_type;
1666 typedef std::forward_iterator_tag iterator_category;
1667
1668 _Local_iterator() = default;
1669
1670 _Local_iterator(const __hash_code_base& __base,
1671 _Hash_node<_Value, __cache>* __p,
1672 std::size_t __bkt, std::size_t __bkt_count)
1673 : __base_type(__base, __p, __bkt, __bkt_count)
1674 { }
1675
1676 reference
1677 operator*() const
1678 { return this->_M_cur->_M_v(); }
1679
1680 pointer
1681 operator->() const
1682 { return this->_M_cur->_M_valptr(); }
1683
1684 _Local_iterator&
1685 operator++()
1686 {
1687 this->_M_incr();
1688 return *this;
1689 }
1690
1691 _Local_iterator
1692 operator++(int)
1693 {
1694 _Local_iterator __tmp(*this);
1695 this->_M_incr();
1696 return __tmp;
1697 }
1698 };
1699
1700 /// local const_iterators
1701 template<typename _Key, typename _Value, typename _ExtractKey,
1702 typename _H1, typename _H2, typename _Hash,
1703 bool __constant_iterators, bool __cache>
1704 struct _Local_const_iterator
1705 : public _Local_iterator_base<_Key, _Value, _ExtractKey,
1706 _H1, _H2, _Hash, __cache>
1707 {
1708 private:
1709 using __base_type = _Local_iterator_base<_Key, _Value, _ExtractKey,
1710 _H1, _H2, _Hash, __cache>;
1711 using __hash_code_base = typename __base_type::__hash_code_base;
1712
1713 public:
1714 typedef _Value value_type;
1715 typedef const _Value* pointer;
1716 typedef const _Value& reference;
1717 typedef std::ptrdiff_t difference_type;
1718 typedef std::forward_iterator_tag iterator_category;
1719
1720 _Local_const_iterator() = default;
1721
1722 _Local_const_iterator(const __hash_code_base& __base,
1723 _Hash_node<_Value, __cache>* __p,
1724 std::size_t __bkt, std::size_t __bkt_count)
1725 : __base_type(__base, __p, __bkt, __bkt_count)
1726 { }
1727
1728 _Local_const_iterator(const _Local_iterator<_Key, _Value, _ExtractKey,
1729 _H1, _H2, _Hash,
1730 __constant_iterators,
1731 __cache>& __x)
1732 : __base_type(__x)
1733 { }
1734
1735 reference
1736 operator*() const
1737 { return this->_M_cur->_M_v(); }
1738
1739 pointer
1740 operator->() const
1741 { return this->_M_cur->_M_valptr(); }
1742
1743 _Local_const_iterator&
1744 operator++()
1745 {
1746 this->_M_incr();
1747 return *this;
1748 }
1749
1750 _Local_const_iterator
1751 operator++(int)
1752 {
1753 _Local_const_iterator __tmp(*this);
1754 this->_M_incr();
1755 return __tmp;
1756 }
1757 };
1758
1759 /**
1760 * Primary class template _Hashtable_base.
1761 *
1762 * Helper class adding management of _Equal functor to
1763 * _Hash_code_base type.
1764 *
1765 * Base class templates are:
1766 * - __detail::_Hash_code_base
1767 * - __detail::_Hashtable_ebo_helper
1768 */
1769 template<typename _Key, typename _Value,
1770 typename _ExtractKey, typename _Equal,
1771 typename _H1, typename _H2, typename _Hash, typename _Traits>
1772 struct _Hashtable_base
1773 : public _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash,
1774 _Traits::__hash_cached::value>,
1775 private _Hashtable_ebo_helper<0, _Equal>
1776 {
1777 public:
1778 typedef _Key key_type;
1779 typedef _Value value_type;
1780 typedef _Equal key_equal;
1781 typedef std::size_t size_type;
1782 typedef std::ptrdiff_t difference_type;
1783
1784 using __traits_type = _Traits;
1785 using __hash_cached = typename __traits_type::__hash_cached;
1786 using __constant_iterators = typename __traits_type::__constant_iterators;
1787 using __unique_keys = typename __traits_type::__unique_keys;
1788
1789 using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey,
1790 _H1, _H2, _Hash,
1791 __hash_cached::value>;
1792
1793 using __hash_code = typename __hash_code_base::__hash_code;
1794 using __node_type = typename __hash_code_base::__node_type;
1795
1796 using iterator = __detail::_Node_iterator<value_type,
1797 __constant_iterators::value,
1798 __hash_cached::value>;
1799
1800 using const_iterator = __detail::_Node_const_iterator<value_type,
1801 __constant_iterators::value,
1802 __hash_cached::value>;
1803
1804 using local_iterator = __detail::_Local_iterator<key_type, value_type,
1805 _ExtractKey, _H1, _H2, _Hash,
1806 __constant_iterators::value,
1807 __hash_cached::value>;
1808
1809 using const_local_iterator = __detail::_Local_const_iterator<key_type,
1810 value_type,
1811 _ExtractKey, _H1, _H2, _Hash,
1812 __constant_iterators::value,
1813 __hash_cached::value>;
1814
1815 using __ireturn_type = typename std::conditional<__unique_keys::value,
1816 std::pair<iterator, bool>,
1817 iterator>::type;
1818 private:
1819 using _EqualEBO = _Hashtable_ebo_helper<0, _Equal>;
1820 using _EqualHelper = _Equal_helper<_Key, _Value, _ExtractKey, _Equal,
1821 __hash_code, __hash_cached::value>;
1822
1823 protected:
1824 _Hashtable_base() = default;
1825 _Hashtable_base(const _ExtractKey& __ex, const _H1& __h1, const _H2& __h2,
1826 const _Hash& __hash, const _Equal& __eq)
1827 : __hash_code_base(__ex, __h1, __h2, __hash), _EqualEBO(__eq)
1828 { }
1829
1830 bool
1831 _M_equals(const _Key& __k, __hash_code __c, __node_type* __n) const
1832 {
1833 return _EqualHelper::_S_equals(_M_eq(), this->_M_extract(),
1834 __k, __c, __n);
1835 }
1836
1837 void
1838 _M_swap(_Hashtable_base& __x)
1839 {
1840 __hash_code_base::_M_swap(__x);
1841 std::swap(_M_eq(), __x._M_eq());
1842 }
1843
1844 const _Equal&
1845 _M_eq() const { return _EqualEBO::_S_cget(*this); }
1846
1847 _Equal&
1848 _M_eq() { return _EqualEBO::_S_get(*this); }
1849 };
1850
1851 /**
1852 * struct _Equality_base.
1853 *
1854 * Common types and functions for class _Equality.
1855 */
1856 struct _Equality_base
1857 {
1858 protected:
1859 template<typename _Uiterator>
1860 static bool
1861 _S_is_permutation(_Uiterator, _Uiterator, _Uiterator);
1862 };
1863
1864 // See std::is_permutation in N3068.
1865 template<typename _Uiterator>
1866 bool
1867 _Equality_base::
1868 _S_is_permutation(_Uiterator __first1, _Uiterator __last1,
1869 _Uiterator __first2)
1870 {
1871 for (; __first1 != __last1; ++__first1, ++__first2)
1872 if (!(*__first1 == *__first2))
1873 break;
1874
1875 if (__first1 == __last1)
1876 return true;
1877
1878 _Uiterator __last2 = __first2;
1879 std::advance(__last2, std::distance(__first1, __last1));
1880
1881 for (_Uiterator __it1 = __first1; __it1 != __last1; ++__it1)
1882 {
1883 _Uiterator __tmp = __first1;
1884 while (__tmp != __it1 && !bool(*__tmp == *__it1))
1885 ++__tmp;
1886
1887 // We've seen this one before.
1888 if (__tmp != __it1)
1889 continue;
1890
1891 std::ptrdiff_t __n2 = 0;
1892 for (__tmp = __first2; __tmp != __last2; ++__tmp)
1893 if (*__tmp == *__it1)
1894 ++__n2;
1895
1896 if (!__n2)
1897 return false;
1898
1899 std::ptrdiff_t __n1 = 0;
1900 for (__tmp = __it1; __tmp != __last1; ++__tmp)
1901 if (*__tmp == *__it1)
1902 ++__n1;
1903
1904 if (__n1 != __n2)
1905 return false;
1906 }
1907 return true;
1908 }
1909
1910 /**
1911 * Primary class template _Equality.
1912 *
1913 * This is for implementing equality comparison for unordered
1914 * containers, per N3068, by John Lakos and Pablo Halpern.
1915 * Algorithmically, we follow closely the reference implementations
1916 * therein.
1917 */
1918 template<typename _Key, typename _Value, typename _Alloc,
1919 typename _ExtractKey, typename _Equal,
1920 typename _H1, typename _H2, typename _Hash,
1921 typename _RehashPolicy, typename _Traits,
1922 bool _Unique_keys = _Traits::__unique_keys::value>
1923 struct _Equality;
1924
1925 /// Specialization.
1926 template<typename _Key, typename _Value, typename _Alloc,
1927 typename _ExtractKey, typename _Equal,
1928 typename _H1, typename _H2, typename _Hash,
1929 typename _RehashPolicy, typename _Traits>
1930 struct _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1931 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>
1932 {
1933 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1934 _H1, _H2, _Hash, _RehashPolicy, _Traits>;
1935
1936 bool
1937 _M_equal(const __hashtable&) const;
1938 };
1939
1940 template<typename _Key, typename _Value, typename _Alloc,
1941 typename _ExtractKey, typename _Equal,
1942 typename _H1, typename _H2, typename _Hash,
1943 typename _RehashPolicy, typename _Traits>
1944 bool
1945 _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1946 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
1947 _M_equal(const __hashtable& __other) const
1948 {
1949 const __hashtable* __this = static_cast<const __hashtable*>(this);
1950
1951 if (__this->size() != __other.size())
1952 return false;
1953
1954 for (auto __itx = __this->begin(); __itx != __this->end(); ++__itx)
1955 {
1956 const auto __ity = __other.find(_ExtractKey()(*__itx));
1957 if (__ity == __other.end() || !bool(*__ity == *__itx))
1958 return false;
1959 }
1960 return true;
1961 }
1962
1963 /// Specialization.
1964 template<typename _Key, typename _Value, typename _Alloc,
1965 typename _ExtractKey, typename _Equal,
1966 typename _H1, typename _H2, typename _Hash,
1967 typename _RehashPolicy, typename _Traits>
1968 struct _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1969 _H1, _H2, _Hash, _RehashPolicy, _Traits, false>
1970 : public _Equality_base
1971 {
1972 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1973 _H1, _H2, _Hash, _RehashPolicy, _Traits>;
1974
1975 bool
1976 _M_equal(const __hashtable&) const;
1977 };
1978
1979 template<typename _Key, typename _Value, typename _Alloc,
1980 typename _ExtractKey, typename _Equal,
1981 typename _H1, typename _H2, typename _Hash,
1982 typename _RehashPolicy, typename _Traits>
1983 bool
1984 _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1985 _H1, _H2, _Hash, _RehashPolicy, _Traits, false>::
1986 _M_equal(const __hashtable& __other) const
1987 {
1988 const __hashtable* __this = static_cast<const __hashtable*>(this);
1989
1990 if (__this->size() != __other.size())
1991 return false;
1992
1993 for (auto __itx = __this->begin(); __itx != __this->end();)
1994 {
1995 const auto __xrange = __this->equal_range(_ExtractKey()(*__itx));
1996 const auto __yrange = __other.equal_range(_ExtractKey()(*__itx));
1997
1998 if (std::distance(__xrange.first, __xrange.second)
1999 != std::distance(__yrange.first, __yrange.second))
2000 return false;
2001
2002 if (!_S_is_permutation(__xrange.first, __xrange.second,
2003 __yrange.first))
2004 return false;
2005
2006 __itx = __xrange.second;
2007 }
2008 return true;
2009 }
2010
2011 /**
2012 * This type deals with all allocation and keeps an allocator instance through
2013 * inheritance to benefit from EBO when possible.
2014 */
2015 template<typename _NodeAlloc>
2016 struct _Hashtable_alloc : private _Hashtable_ebo_helper<0, _NodeAlloc>
2017 {
2018 private:
2019 using __ebo_node_alloc = _Hashtable_ebo_helper<0, _NodeAlloc>;
2020 public:
2021 using __node_type = typename _NodeAlloc::value_type;
2022 using __node_alloc_type = _NodeAlloc;
2023 // Use __gnu_cxx to benefit from _S_always_equal and al.
2024 using __node_alloc_traits = __gnu_cxx::__alloc_traits<__node_alloc_type>;
2025
2026 using __value_alloc_traits = typename __node_alloc_traits::template
2027 rebind_traits<typename __node_type::value_type>;
2028
2029 using __node_base = __detail::_Hash_node_base;
2030 using __bucket_type = __node_base*;
2031 using __bucket_alloc_type =
2032 __alloc_rebind<__node_alloc_type, __bucket_type>;
2033 using __bucket_alloc_traits = std::allocator_traits<__bucket_alloc_type>;
2034
2035 _Hashtable_alloc() = default;
2036 _Hashtable_alloc(const _Hashtable_alloc&) = default;
2037 _Hashtable_alloc(_Hashtable_alloc&&) = default;
2038
2039 template<typename _Alloc>
2040 _Hashtable_alloc(_Alloc&& __a)
2041 : __ebo_node_alloc(std::forward<_Alloc>(__a))
2042 { }
2043
2044 __node_alloc_type&
2045 _M_node_allocator()
2046 { return __ebo_node_alloc::_S_get(*this); }
2047
2048 const __node_alloc_type&
2049 _M_node_allocator() const
2050 { return __ebo_node_alloc::_S_cget(*this); }
2051
2052 template<typename... _Args>
2053 __node_type*
2054 _M_allocate_node(_Args&&... __args);
2055
2056 void
2057 _M_deallocate_node(__node_type* __n);
2058
2059 // Deallocate the linked list of nodes pointed to by __n
2060 void
2061 _M_deallocate_nodes(__node_type* __n);
2062
2063 __bucket_type*
2064 _M_allocate_buckets(std::size_t __n);
2065
2066 void
2067 _M_deallocate_buckets(__bucket_type*, std::size_t __n);
2068 };
2069
2070 // Definitions of class template _Hashtable_alloc's out-of-line member
2071 // functions.
2072 template<typename _NodeAlloc>
2073 template<typename... _Args>
2074 typename _Hashtable_alloc<_NodeAlloc>::__node_type*
2075 _Hashtable_alloc<_NodeAlloc>::_M_allocate_node(_Args&&... __args)
2076 {
2077 auto __nptr = __node_alloc_traits::allocate(_M_node_allocator(), 1);
2078 __node_type* __n = std::__to_address(__nptr);
2079 __try
2080 {
2081 ::new ((void*)__n) __node_type;
2082 __node_alloc_traits::construct(_M_node_allocator(),
2083 __n->_M_valptr(),
2084 std::forward<_Args>(__args)...);
2085 return __n;
2086 }
2087 __catch(...)
2088 {
2089 __node_alloc_traits::deallocate(_M_node_allocator(), __nptr, 1);
2090 __throw_exception_again;
2091 }
2092 }
2093
2094 template<typename _NodeAlloc>
2095 void
2096 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_node(__node_type* __n)
2097 {
2098 typedef typename __node_alloc_traits::pointer _Ptr;
2099 auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__n);
2100 __node_alloc_traits::destroy(_M_node_allocator(), __n->_M_valptr());
2101 __n->~__node_type();
2102 __node_alloc_traits::deallocate(_M_node_allocator(), __ptr, 1);
2103 }
2104
2105 template<typename _NodeAlloc>
2106 void
2107 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_nodes(__node_type* __n)
2108 {
2109 while (__n)
2110 {
2111 __node_type* __tmp = __n;
2112 __n = __n->_M_next();
2113 _M_deallocate_node(__tmp);
2114 }
2115 }
2116
2117 template<typename _NodeAlloc>
2118 typename _Hashtable_alloc<_NodeAlloc>::__bucket_type*
2119 _Hashtable_alloc<_NodeAlloc>::_M_allocate_buckets(std::size_t __n)
2120 {
2121 __bucket_alloc_type __alloc(_M_node_allocator());
2122
2123 auto __ptr = __bucket_alloc_traits::allocate(__alloc, __n);
2124 __bucket_type* __p = std::__to_address(__ptr);
2125 __builtin_memset(__p, 0, __n * sizeof(__bucket_type));
2126 return __p;
2127 }
2128
2129 template<typename _NodeAlloc>
2130 void
2131 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_buckets(__bucket_type* __bkts,
2132 std::size_t __n)
2133 {
2134 typedef typename __bucket_alloc_traits::pointer _Ptr;
2135 auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__bkts);
2136 __bucket_alloc_type __alloc(_M_node_allocator());
2137 __bucket_alloc_traits::deallocate(__alloc, __ptr, __n);
2138 }
2139
2140 //@} hashtable-detail
2141} // namespace __detail
2142_GLIBCXX_END_NAMESPACE_VERSION
2143} // namespace std
2144
2145#endif // _HASHTABLE_POLICY_H
2146