libstdc++
hashtable_policy.h
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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 
38 namespace 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 
48 namespace __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>
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,
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,
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>
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>
201  {
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  */
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>
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>
290  {
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,
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>
320  : public _Node_iterator_base<_Value, __cache>
321  {
322  private:
324  using __node_type = typename __base_type::__node_type;
325 
326  public:
327  typedef _Value value_type;
328  typedef std::ptrdiff_t difference_type;
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 
353  operator++() noexcept
354  {
355  this->_M_incr();
356  return *this;
357  }
358 
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>
371  : public _Node_iterator_base<_Value, __cache>
372  {
373  private:
375  using __node_type = typename __base_type::__node_type;
376 
377  public:
378  typedef _Value value_type;
379  typedef std::ptrdiff_t difference_type;
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 
405  operator++() noexcept
406  {
407  this->_M_incr();
408  return *this;
409  }
410 
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).
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.
443 
444  /// Default value for rehash policy. Bucket size is (usually) the
445  /// smallest prime that keeps the load factor small enough.
447  {
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).
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.
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.
533  {
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).
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,
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>
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;
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>
1003 
1004  template<typename _Pair>
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>>
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)>
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>
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>
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:
1192 
1193  protected:
1194  typedef void* __hash_code;
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:
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;
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 
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;
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>
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:
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,
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>
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;
1667 
1668  _Local_iterator() = default;
1669 
1670  _Local_iterator(const __hash_code_base& __base,
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 
1685  operator++()
1686  {
1687  this->_M_incr();
1688  return *this;
1689  }
1690 
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>
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;
1719 
1720  _Local_const_iterator() = default;
1721 
1722  _Local_const_iterator(const __hash_code_base& __base,
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 
1744  operator++()
1745  {
1746  this->_M_incr();
1747  return *this;
1748  }
1749 
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,
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  */
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
Default value for rehash policy. Bucket size is (usually) the smallest prime that keeps the load fact...
Primary class template, tuple.
Definition: tuple:53
tuple_element
Definition: array:359
_GLIBCXX14_CONSTEXPR std::size_t __clp2(std::size_t __n) noexcept
Compute closest power of 2.
Define a member typedef type only if a boolean constant is true.
Definition: type_traits:1987
Define a member typedef type to one of two argument types.
Definition: type_traits:104
integral_constant< bool, false > false_type
The type used as a compile-time boolean with false value.
Definition: type_traits:90
constexpr pair< typename __decay_and_strip< _T1 >::__type, typename __decay_and_strip< _T2 >::__type > make_pair(_T1 &&__x, _T2 &&__y)
A convenience wrapper for creating a pair from two objects.
Definition: stl_pair.h:519
Uniform interface to all allocator types.
constexpr _Tp && forward(typename std::remove_reference< _Tp >::type &__t) noexcept
Forward an lvalue.
Definition: move.h:74
Node const_iterators, used to iterate through all the hashtable.
integral_constant< bool, true > true_type
The type used as a compile-time boolean with true value.
Definition: type_traits:87
_GLIBCXX17_INLINE constexpr piecewise_construct_t piecewise_construct
piecewise_construct
Definition: stl_pair.h:79
ISO C++ entities toplevel namespace is std.
Uniform interface to C++98 and C++11 allocators.
is_constructible
Definition: type_traits:932
Rehash policy providing power of 2 bucket numbers. Avoids modulo operations.
_GLIBCXX17_CONSTEXPR iterator_traits< _InputIterator >::difference_type distance(_InputIterator __first, _InputIterator __last)
A generalization of pointer arithmetic.
Default ranged hash function H. In principle it should be a function object composed from objects of ...
Marking input iterators.
integral_constant
Definition: type_traits:69
Node iterators, used to iterate through all the hashtable.
initializer_list
_GLIBCXX17_CONSTEXPR void advance(_InputIterator &__i, _Distance __n)
A generalization of pointer arithmetic.
Common iterator class.
Struct holding two objects of arbitrary type.
Definition: stl_pair.h:198
Forward iterators support a superset of input iterator operations.
Range hashing function assuming that second arg is a power of 2.
constexpr iterator_traits< _Iter >::iterator_category __iterator_category(const _Iter &)
Default range hashing function: use division to fold a large number into the range [0...
Uniform interface to all pointer-like types.
Definition: ptr_traits.h:78
Base class for node iterators.
is_empty
Definition: type_traits:704
complex< _Tp > operator*(const complex< _Tp > &__x, const complex< _Tp > &__y)
Return new complex value x times y.
Definition: complex:386