1 // TR1 hashtable.h header -*- C++ -*-
2 
3 // Copyright (C) 2007-2018 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 tr1/hashtable.h
26  *  This is an internal header file, included by other library headers.
27  *  Do not attempt to use it directly.
28  *  @headername{tr1/unordered_set, tr1/unordered_map}
29  */
30 
31 #ifndef _GLIBCXX_TR1_HASHTABLE_H
32 #define _GLIBCXX_TR1_HASHTABLE_H 1
33 
34 #pragma GCC system_header
35 
36 #include <tr1/hashtable_policy.h>
37 
38 namespace std _GLIBCXX_VISIBILITY(default)
39 {
40 _GLIBCXX_BEGIN_NAMESPACE_VERSION
41 
42 namespace tr1
43 {
44   // Class template _Hashtable, class definition.
45 
46   // Meaning of class template _Hashtable's template parameters
47 
48   // _Key and _Value: arbitrary CopyConstructible types.
49 
50   // _Allocator: an allocator type ([lib.allocator.requirements]) whose
51   // value type is Value.  As a conforming extension, we allow for
52   // value type != Value.
53 
54   // _ExtractKey: function object that takes a object of type Value
55   // and returns a value of type _Key.
56 
57   // _Equal: function object that takes two objects of type k and returns
58   // a bool-like value that is true if the two objects are considered equal.
59 
60   // _H1: the hash function.  A unary function object with argument type
61   // Key and result type size_t.  Return values should be distributed
62   // over the entire range [0, numeric_limits<size_t>:::max()].
63 
64   // _H2: the range-hashing function (in the terminology of Tavori and
65   // Dreizin).  A binary function object whose argument types and result
66   // type are all size_t.  Given arguments r and N, the return value is
67   // in the range [0, N).
68 
69   // _Hash: the ranged hash function (Tavori and Dreizin). A binary function
70   // whose argument types are _Key and size_t and whose result type is
71   // size_t.  Given arguments k and N, the return value is in the range
72   // [0, N).  Default: hash(k, N) = h2(h1(k), N).  If _Hash is anything other
73   // than the default, _H1 and _H2 are ignored.
74 
75   // _RehashPolicy: Policy class with three members, all of which govern
76   // the bucket count. _M_next_bkt(n) returns a bucket count no smaller
77   // than n.  _M_bkt_for_elements(n) returns a bucket count appropriate
78   // for an element count of n.  _M_need_rehash(n_bkt, n_elt, n_ins)
79   // determines whether, if the current bucket count is n_bkt and the
80   // current element count is n_elt, we need to increase the bucket
81   // count.  If so, returns make_pair(true, n), where n is the new
82   // bucket count.  If not, returns make_pair(false, <anything>).
83 
84   // ??? Right now it is hard-wired that the number of buckets never
85   // shrinks.  Should we allow _RehashPolicy to change that?
86 
87   // __cache_hash_code: bool.  true if we store the value of the hash
88   // function along with the value.  This is a time-space tradeoff.
89   // Storing it may improve lookup speed by reducing the number of times
90   // we need to call the Equal function.
91 
92   // __constant_iterators: bool.  true if iterator and const_iterator are
93   // both constant iterator types.  This is true for unordered_set and
94   // unordered_multiset, false for unordered_map and unordered_multimap.
95 
96   // __unique_keys: bool.  true if the return value of _Hashtable::count(k)
97   // is always at most one, false if it may be an arbitrary number.  This
98   // true for unordered_set and unordered_map, false for unordered_multiset
99   // and unordered_multimap.
100 
101   template<typename _Key, typename _Value, typename _Allocator,
102 	   typename _ExtractKey, typename _Equal,
103 	   typename _H1, typename _H2, typename _Hash,
104 	   typename _RehashPolicy,
105 	   bool __cache_hash_code,
106 	   bool __constant_iterators,
107 	   bool __unique_keys>
108     class _Hashtable
109     : public __detail::_Rehash_base<_RehashPolicy,
110 				    _Hashtable<_Key, _Value, _Allocator,
111 					       _ExtractKey,
112 					       _Equal, _H1, _H2, _Hash,
113 					       _RehashPolicy,
114 					       __cache_hash_code,
115 					       __constant_iterators,
116 					       __unique_keys> >,
117       public __detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Equal,
118 				       _H1, _H2, _Hash, __cache_hash_code>,
119       public __detail::_Map_base<_Key, _Value, _ExtractKey, __unique_keys,
120 				 _Hashtable<_Key, _Value, _Allocator,
121 					    _ExtractKey,
122 					    _Equal, _H1, _H2, _Hash,
123 					    _RehashPolicy,
124 					    __cache_hash_code,
125 					    __constant_iterators,
126 					    __unique_keys> >
127     {
128     public:
129       typedef _Allocator                                  allocator_type;
130       typedef _Value                                      value_type;
131       typedef _Key                                        key_type;
132       typedef _Equal                                      key_equal;
133       // mapped_type, if present, comes from _Map_base.
134       // hasher, if present, comes from _Hash_code_base.
135       typedef typename _Allocator::difference_type        difference_type;
136       typedef typename _Allocator::size_type              size_type;
137       typedef typename _Allocator::pointer                pointer;
138       typedef typename _Allocator::const_pointer          const_pointer;
139       typedef typename _Allocator::reference              reference;
140       typedef typename _Allocator::const_reference        const_reference;
141 
142       typedef __detail::_Node_iterator<value_type, __constant_iterators,
143 				       __cache_hash_code>
144 							  local_iterator;
145       typedef __detail::_Node_const_iterator<value_type,
146 					     __constant_iterators,
147 					     __cache_hash_code>
148 							  const_local_iterator;
149 
150       typedef __detail::_Hashtable_iterator<value_type, __constant_iterators,
151 					    __cache_hash_code>
152 							  iterator;
153       typedef __detail::_Hashtable_const_iterator<value_type,
154 						  __constant_iterators,
155 						  __cache_hash_code>
156 							  const_iterator;
157 
158       template<typename _Key2, typename _Value2, typename _Ex2, bool __unique2,
159 	       typename _Hashtable2>
160 	friend struct __detail::_Map_base;
161 
162     private:
163       typedef __detail::_Hash_node<_Value, __cache_hash_code> _Node;
164       typedef typename _Allocator::template rebind<_Node>::other
165 							_Node_allocator_type;
166       typedef typename _Allocator::template rebind<_Node*>::other
167 							_Bucket_allocator_type;
168 
169       typedef typename _Allocator::template rebind<_Value>::other
170 							_Value_allocator_type;
171 
172       _Node_allocator_type   _M_node_allocator;
173       _Node**                _M_buckets;
174       size_type              _M_bucket_count;
175       size_type              _M_element_count;
176       _RehashPolicy          _M_rehash_policy;
177 
178       _Node*
179       _M_allocate_node(const value_type& __v);
180 
181       void
182       _M_deallocate_node(_Node* __n);
183 
184       void
185       _M_deallocate_nodes(_Node**, size_type);
186 
187       _Node**
188       _M_allocate_buckets(size_type __n);
189 
190       void
191       _M_deallocate_buckets(_Node**, size_type __n);
192 
193     public:
194       // Constructor, destructor, assignment, swap
195       _Hashtable(size_type __bucket_hint,
196 		 const _H1&, const _H2&, const _Hash&,
197 		 const _Equal&, const _ExtractKey&,
198 		 const allocator_type&);
199 
200       template<typename _InputIterator>
201 	_Hashtable(_InputIterator __first, _InputIterator __last,
202 		   size_type __bucket_hint,
203 		   const _H1&, const _H2&, const _Hash&,
204 		   const _Equal&, const _ExtractKey&,
205 		   const allocator_type&);
206 
207       _Hashtable(const _Hashtable&);
208 
209       _Hashtable&
210       operator=(const _Hashtable&);
211 
212       ~_Hashtable();
213 
214       void swap(_Hashtable&);
215 
216       // Basic container operations
217       iterator
218       begin()
219       {
220 	iterator __i(_M_buckets);
221 	if (!__i._M_cur_node)
222 	  __i._M_incr_bucket();
223 	return __i;
224       }
225 
226       const_iterator
227       begin() const
228       {
229 	const_iterator __i(_M_buckets);
230 	if (!__i._M_cur_node)
231 	  __i._M_incr_bucket();
232 	return __i;
233       }
234 
235       iterator
236       end()
237       { return iterator(_M_buckets + _M_bucket_count); }
238 
239       const_iterator
240       end() const
241       { return const_iterator(_M_buckets + _M_bucket_count); }
242 
243       size_type
244       size() const
245       { return _M_element_count; }
246 
247       bool
248       empty() const
249       { return size() == 0; }
250 
251       allocator_type
252       get_allocator() const
253       { return allocator_type(_M_node_allocator); }
254 
255       _Value_allocator_type
256       _M_get_Value_allocator() const
257       { return _Value_allocator_type(_M_node_allocator); }
258 
259       size_type
260       max_size() const
261       { return _M_node_allocator.max_size(); }
262 
263       // Observers
264       key_equal
265       key_eq() const
266       { return this->_M_eq; }
267 
268       // hash_function, if present, comes from _Hash_code_base.
269 
270       // Bucket operations
271       size_type
272       bucket_count() const
273       { return _M_bucket_count; }
274 
275       size_type
276       max_bucket_count() const
277       { return max_size(); }
278 
279       size_type
280       bucket_size(size_type __n) const
281       { return std::distance(begin(__n), end(__n)); }
282 
283       size_type
284       bucket(const key_type& __k) const
285       {
286 	return this->_M_bucket_index(__k, this->_M_hash_code(__k),
287 				     bucket_count());
288       }
289 
290       local_iterator
291       begin(size_type __n)
292       { return local_iterator(_M_buckets[__n]); }
293 
294       local_iterator
295       end(size_type)
296       { return local_iterator(0); }
297 
298       const_local_iterator
299       begin(size_type __n) const
300       { return const_local_iterator(_M_buckets[__n]); }
301 
302       const_local_iterator
303       end(size_type) const
304       { return const_local_iterator(0); }
305 
306       float
307       load_factor() const
308       {
309 	return static_cast<float>(size()) / static_cast<float>(bucket_count());
310       }
311 
312       // max_load_factor, if present, comes from _Rehash_base.
313 
314       // Generalization of max_load_factor.  Extension, not found in TR1.  Only
315       // useful if _RehashPolicy is something other than the default.
316       const _RehashPolicy&
317       __rehash_policy() const
318       { return _M_rehash_policy; }
319 
320       void
321       __rehash_policy(const _RehashPolicy&);
322 
323       // Lookup.
324       iterator
325       find(const key_type& __k);
326 
327       const_iterator
328       find(const key_type& __k) const;
329 
330       size_type
331       count(const key_type& __k) const;
332 
333       std::pair<iterator, iterator>
334       equal_range(const key_type& __k);
335 
336       std::pair<const_iterator, const_iterator>
337       equal_range(const key_type& __k) const;
338 
339     private:			// Find, insert and erase helper functions
340       // ??? This dispatching is a workaround for the fact that we don't
341       // have partial specialization of member templates; it would be
342       // better to just specialize insert on __unique_keys.  There may be a
343       // cleaner workaround.
344       typedef typename __gnu_cxx::__conditional_type<__unique_keys,
345 		       	    std::pair<iterator, bool>, iterator>::__type
346 	_Insert_Return_Type;
347 
348       typedef typename __gnu_cxx::__conditional_type<__unique_keys,
349 					  std::_Select1st<_Insert_Return_Type>,
350 				  	  std::_Identity<_Insert_Return_Type>
351 				   >::__type
352 	_Insert_Conv_Type;
353 
354       _Node*
355       _M_find_node(_Node*, const key_type&,
356 		   typename _Hashtable::_Hash_code_type) const;
357 
358       iterator
359       _M_insert_bucket(const value_type&, size_type,
360 		       typename _Hashtable::_Hash_code_type);
361 
362       std::pair<iterator, bool>
363       _M_insert(const value_type&, std::tr1::true_type);
364 
365       iterator
366       _M_insert(const value_type&, std::tr1::false_type);
367 
368       void
369       _M_erase_node(_Node*, _Node**);
370 
371     public:
372       // Insert and erase
373       _Insert_Return_Type
374       insert(const value_type& __v)
375       { return _M_insert(__v, std::tr1::integral_constant<bool,
376 			 __unique_keys>()); }
377 
378       iterator
379       insert(iterator, const value_type& __v)
380       { return iterator(_Insert_Conv_Type()(this->insert(__v))); }
381 
382       const_iterator
383       insert(const_iterator, const value_type& __v)
384       { return const_iterator(_Insert_Conv_Type()(this->insert(__v))); }
385 
386       template<typename _InputIterator>
387 	void
388 	insert(_InputIterator __first, _InputIterator __last);
389 
390       iterator
391       erase(iterator);
392 
393       const_iterator
394       erase(const_iterator);
395 
396       size_type
397       erase(const key_type&);
398 
399       iterator
400       erase(iterator, iterator);
401 
402       const_iterator
403       erase(const_iterator, const_iterator);
404 
405       void
406       clear();
407 
408       // Set number of buckets to be appropriate for container of n element.
409       void rehash(size_type __n);
410 
411     private:
412       // Unconditionally change size of bucket array to n.
413       void _M_rehash(size_type __n);
414     };
415 
416 
417   // Definitions of class template _Hashtable's out-of-line member functions.
418   template<typename _Key, typename _Value,
419 	   typename _Allocator, typename _ExtractKey, typename _Equal,
420 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
421 	   bool __chc, bool __cit, bool __uk>
422     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
423 			_H1, _H2, _Hash, _RehashPolicy,
424 			__chc, __cit, __uk>::_Node*
425     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
426 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
427     _M_allocate_node(const value_type& __v)
428     {
429       _Node* __n = _M_node_allocator.allocate(1);
430       __try
431 	{
432 	  _M_get_Value_allocator().construct(&__n->_M_v, __v);
433 	  __n->_M_next = 0;
434 	  return __n;
435 	}
436       __catch(...)
437 	{
438 	  _M_node_allocator.deallocate(__n, 1);
439 	  __throw_exception_again;
440 	}
441     }
442 
443   template<typename _Key, typename _Value,
444 	   typename _Allocator, typename _ExtractKey, typename _Equal,
445 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
446 	   bool __chc, bool __cit, bool __uk>
447     void
448     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
449 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
450     _M_deallocate_node(_Node* __n)
451     {
452       _M_get_Value_allocator().destroy(&__n->_M_v);
453       _M_node_allocator.deallocate(__n, 1);
454     }
455 
456   template<typename _Key, typename _Value,
457 	   typename _Allocator, typename _ExtractKey, typename _Equal,
458 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
459 	   bool __chc, bool __cit, bool __uk>
460     void
461     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
462 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
463     _M_deallocate_nodes(_Node** __array, size_type __n)
464     {
465       for (size_type __i = 0; __i < __n; ++__i)
466 	{
467 	  _Node* __p = __array[__i];
468 	  while (__p)
469 	    {
470 	      _Node* __tmp = __p;
471 	      __p = __p->_M_next;
472 	      _M_deallocate_node(__tmp);
473 	    }
474 	  __array[__i] = 0;
475 	}
476     }
477 
478   template<typename _Key, typename _Value,
479 	   typename _Allocator, typename _ExtractKey, typename _Equal,
480 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
481 	   bool __chc, bool __cit, bool __uk>
482     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
483 			_H1, _H2, _Hash, _RehashPolicy,
484 			__chc, __cit, __uk>::_Node**
485     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
486 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
487     _M_allocate_buckets(size_type __n)
488     {
489       _Bucket_allocator_type __alloc(_M_node_allocator);
490 
491       // We allocate one extra bucket to hold a sentinel, an arbitrary
492       // non-null pointer.  Iterator increment relies on this.
493       _Node** __p = __alloc.allocate(__n + 1);
494       std::fill(__p, __p + __n, (_Node*) 0);
495       __p[__n] = reinterpret_cast<_Node*>(0x1000);
496       return __p;
497     }
498 
499   template<typename _Key, typename _Value,
500 	   typename _Allocator, typename _ExtractKey, typename _Equal,
501 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
502 	   bool __chc, bool __cit, bool __uk>
503     void
504     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
505 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
506     _M_deallocate_buckets(_Node** __p, size_type __n)
507     {
508       _Bucket_allocator_type __alloc(_M_node_allocator);
509       __alloc.deallocate(__p, __n + 1);
510     }
511 
512   template<typename _Key, typename _Value,
513 	   typename _Allocator, typename _ExtractKey, typename _Equal,
514 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
515 	   bool __chc, bool __cit, bool __uk>
516     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
517 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
518     _Hashtable(size_type __bucket_hint,
519 	       const _H1& __h1, const _H2& __h2, const _Hash& __h,
520 	       const _Equal& __eq, const _ExtractKey& __exk,
521 	       const allocator_type& __a)
522     : __detail::_Rehash_base<_RehashPolicy, _Hashtable>(),
523       __detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Equal,
524 				_H1, _H2, _Hash, __chc>(__exk, __eq,
525 							__h1, __h2, __h),
526       __detail::_Map_base<_Key, _Value, _ExtractKey, __uk, _Hashtable>(),
527       _M_node_allocator(__a),
528       _M_bucket_count(0),
529       _M_element_count(0),
530       _M_rehash_policy()
531     {
532       _M_bucket_count = _M_rehash_policy._M_next_bkt(__bucket_hint);
533       _M_buckets = _M_allocate_buckets(_M_bucket_count);
534     }
535 
536   template<typename _Key, typename _Value,
537 	   typename _Allocator, typename _ExtractKey, typename _Equal,
538 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
539 	   bool __chc, bool __cit, bool __uk>
540     template<typename _InputIterator>
541       _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
542 		 _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
543       _Hashtable(_InputIterator __f, _InputIterator __l,
544 		 size_type __bucket_hint,
545 		 const _H1& __h1, const _H2& __h2, const _Hash& __h,
546 		 const _Equal& __eq, const _ExtractKey& __exk,
547 		 const allocator_type& __a)
548       : __detail::_Rehash_base<_RehashPolicy, _Hashtable>(),
549 	__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Equal,
550 				  _H1, _H2, _Hash, __chc>(__exk, __eq,
551 							  __h1, __h2, __h),
552 	__detail::_Map_base<_Key, _Value, _ExtractKey, __uk, _Hashtable>(),
553 	_M_node_allocator(__a),
554 	_M_bucket_count(0),
555 	_M_element_count(0),
556 	_M_rehash_policy()
557       {
558 	_M_bucket_count = std::max(_M_rehash_policy._M_next_bkt(__bucket_hint),
559 				   _M_rehash_policy.
560 				   _M_bkt_for_elements(__detail::
561 						       __distance_fw(__f,
562 								     __l)));
563 	_M_buckets = _M_allocate_buckets(_M_bucket_count);
564 	__try
565 	  {
566 	    for (; __f != __l; ++__f)
567 	      this->insert(*__f);
568 	  }
569 	__catch(...)
570 	  {
571 	    clear();
572 	    _M_deallocate_buckets(_M_buckets, _M_bucket_count);
573 	    __throw_exception_again;
574 	  }
575       }
576 
577   template<typename _Key, typename _Value,
578 	   typename _Allocator, typename _ExtractKey, typename _Equal,
579 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
580 	   bool __chc, bool __cit, bool __uk>
581     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
582 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
583     _Hashtable(const _Hashtable& __ht)
584     : __detail::_Rehash_base<_RehashPolicy, _Hashtable>(__ht),
585       __detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Equal,
586 				_H1, _H2, _Hash, __chc>(__ht),
587       __detail::_Map_base<_Key, _Value, _ExtractKey, __uk, _Hashtable>(__ht),
588       _M_node_allocator(__ht._M_node_allocator),
589       _M_bucket_count(__ht._M_bucket_count),
590       _M_element_count(__ht._M_element_count),
591       _M_rehash_policy(__ht._M_rehash_policy)
592     {
593       _M_buckets = _M_allocate_buckets(_M_bucket_count);
594       __try
595 	{
596 	  for (size_type __i = 0; __i < __ht._M_bucket_count; ++__i)
597 	    {
598 	      _Node* __n = __ht._M_buckets[__i];
599 	      _Node** __tail = _M_buckets + __i;
600 	      while (__n)
601 		{
602 		  *__tail = _M_allocate_node(__n->_M_v);
603 		  this->_M_copy_code(*__tail, __n);
604 		  __tail = &((*__tail)->_M_next);
605 		  __n = __n->_M_next;
606 		}
607 	    }
608 	}
609       __catch(...)
610 	{
611 	  clear();
612 	  _M_deallocate_buckets(_M_buckets, _M_bucket_count);
613 	  __throw_exception_again;
614 	}
615     }
616 
617   template<typename _Key, typename _Value,
618 	   typename _Allocator, typename _ExtractKey, typename _Equal,
619 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
620 	   bool __chc, bool __cit, bool __uk>
621     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
622 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>&
623     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
624 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
625     operator=(const _Hashtable& __ht)
626     {
627       _Hashtable __tmp(__ht);
628       this->swap(__tmp);
629       return *this;
630     }
631 
632   template<typename _Key, typename _Value,
633 	   typename _Allocator, typename _ExtractKey, typename _Equal,
634 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
635 	   bool __chc, bool __cit, bool __uk>
636     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
637 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
638     ~_Hashtable()
639     {
640       clear();
641       _M_deallocate_buckets(_M_buckets, _M_bucket_count);
642     }
643 
644   template<typename _Key, typename _Value,
645 	   typename _Allocator, typename _ExtractKey, typename _Equal,
646 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
647 	   bool __chc, bool __cit, bool __uk>
648     void
649     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
650 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
651     swap(_Hashtable& __x)
652     {
653       // The only base class with member variables is hash_code_base.  We
654       // define _Hash_code_base::_M_swap because different specializations
655       // have different members.
656       __detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Equal,
657 	_H1, _H2, _Hash, __chc>::_M_swap(__x);
658 
659       // _GLIBCXX_RESOLVE_LIB_DEFECTS
660       // 431. Swapping containers with unequal allocators.
661       std::__alloc_swap<_Node_allocator_type>::_S_do_it(_M_node_allocator,
662 							__x._M_node_allocator);
663 
664       std::swap(_M_rehash_policy, __x._M_rehash_policy);
665       std::swap(_M_buckets, __x._M_buckets);
666       std::swap(_M_bucket_count, __x._M_bucket_count);
667       std::swap(_M_element_count, __x._M_element_count);
668     }
669 
670   template<typename _Key, typename _Value,
671 	   typename _Allocator, typename _ExtractKey, typename _Equal,
672 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
673 	   bool __chc, bool __cit, bool __uk>
674     void
675     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
676 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
677     __rehash_policy(const _RehashPolicy& __pol)
678     {
679       _M_rehash_policy = __pol;
680       size_type __n_bkt = __pol._M_bkt_for_elements(_M_element_count);
681       if (__n_bkt > _M_bucket_count)
682 	_M_rehash(__n_bkt);
683     }
684 
685   template<typename _Key, typename _Value,
686 	   typename _Allocator, typename _ExtractKey, typename _Equal,
687 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
688 	   bool __chc, bool __cit, bool __uk>
689     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
690 			_H1, _H2, _Hash, _RehashPolicy,
691 			__chc, __cit, __uk>::iterator
692     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
693 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
694     find(const key_type& __k)
695     {
696       typename _Hashtable::_Hash_code_type __code = this->_M_hash_code(__k);
697       std::size_t __n = this->_M_bucket_index(__k, __code, _M_bucket_count);
698       _Node* __p = _M_find_node(_M_buckets[__n], __k, __code);
699       return __p ? iterator(__p, _M_buckets + __n) : this->end();
700     }
701 
702   template<typename _Key, typename _Value,
703 	   typename _Allocator, typename _ExtractKey, typename _Equal,
704 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
705 	   bool __chc, bool __cit, bool __uk>
706     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
707 			_H1, _H2, _Hash, _RehashPolicy,
708 			__chc, __cit, __uk>::const_iterator
709     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
710 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
711     find(const key_type& __k) const
712     {
713       typename _Hashtable::_Hash_code_type __code = this->_M_hash_code(__k);
714       std::size_t __n = this->_M_bucket_index(__k, __code, _M_bucket_count);
715       _Node* __p = _M_find_node(_M_buckets[__n], __k, __code);
716       return __p ? const_iterator(__p, _M_buckets + __n) : this->end();
717     }
718 
719   template<typename _Key, typename _Value,
720 	   typename _Allocator, typename _ExtractKey, typename _Equal,
721 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
722 	   bool __chc, bool __cit, bool __uk>
723     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
724 			_H1, _H2, _Hash, _RehashPolicy,
725 			__chc, __cit, __uk>::size_type
726     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
727 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
728     count(const key_type& __k) const
729     {
730       typename _Hashtable::_Hash_code_type __code = this->_M_hash_code(__k);
731       std::size_t __n = this->_M_bucket_index(__k, __code, _M_bucket_count);
732       std::size_t __result = 0;
733       for (_Node* __p = _M_buckets[__n]; __p; __p = __p->_M_next)
734 	if (this->_M_compare(__k, __code, __p))
735 	  ++__result;
736       return __result;
737     }
738 
739   template<typename _Key, typename _Value,
740 	   typename _Allocator, typename _ExtractKey, typename _Equal,
741 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
742 	   bool __chc, bool __cit, bool __uk>
743     std::pair<typename _Hashtable<_Key, _Value, _Allocator,
744 				  _ExtractKey, _Equal, _H1,
745 				  _H2, _Hash, _RehashPolicy,
746 				  __chc, __cit, __uk>::iterator,
747 	      typename _Hashtable<_Key, _Value, _Allocator,
748 				  _ExtractKey, _Equal, _H1,
749 				  _H2, _Hash, _RehashPolicy,
750 				  __chc, __cit, __uk>::iterator>
751     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
752 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
753     equal_range(const key_type& __k)
754     {
755       typename _Hashtable::_Hash_code_type __code = this->_M_hash_code(__k);
756       std::size_t __n = this->_M_bucket_index(__k, __code, _M_bucket_count);
757       _Node** __head = _M_buckets + __n;
758       _Node* __p = _M_find_node(*__head, __k, __code);
759 
760       if (__p)
761 	{
762 	  _Node* __p1 = __p->_M_next;
763 	  for (; __p1; __p1 = __p1->_M_next)
764 	    if (!this->_M_compare(__k, __code, __p1))
765 	      break;
766 
767 	  iterator __first(__p, __head);
768 	  iterator __last(__p1, __head);
769 	  if (!__p1)
770 	    __last._M_incr_bucket();
771 	  return std::make_pair(__first, __last);
772 	}
773       else
774 	return std::make_pair(this->end(), this->end());
775     }
776 
777   template<typename _Key, typename _Value,
778 	   typename _Allocator, typename _ExtractKey, typename _Equal,
779 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
780 	   bool __chc, bool __cit, bool __uk>
781     std::pair<typename _Hashtable<_Key, _Value, _Allocator,
782 				  _ExtractKey, _Equal, _H1,
783 				  _H2, _Hash, _RehashPolicy,
784 				  __chc, __cit, __uk>::const_iterator,
785 	      typename _Hashtable<_Key, _Value, _Allocator,
786 				  _ExtractKey, _Equal, _H1,
787 				  _H2, _Hash, _RehashPolicy,
788 				  __chc, __cit, __uk>::const_iterator>
789     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
790 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
791     equal_range(const key_type& __k) const
792     {
793       typename _Hashtable::_Hash_code_type __code = this->_M_hash_code(__k);
794       std::size_t __n = this->_M_bucket_index(__k, __code, _M_bucket_count);
795       _Node** __head = _M_buckets + __n;
796       _Node* __p = _M_find_node(*__head, __k, __code);
797 
798       if (__p)
799 	{
800 	  _Node* __p1 = __p->_M_next;
801 	  for (; __p1; __p1 = __p1->_M_next)
802 	    if (!this->_M_compare(__k, __code, __p1))
803 	      break;
804 
805 	  const_iterator __first(__p, __head);
806 	  const_iterator __last(__p1, __head);
807 	  if (!__p1)
808 	    __last._M_incr_bucket();
809 	  return std::make_pair(__first, __last);
810 	}
811       else
812 	return std::make_pair(this->end(), this->end());
813     }
814 
815   // Find the node whose key compares equal to k, beginning the search
816   // at p (usually the head of a bucket).  Return zero if no node is found.
817   template<typename _Key, typename _Value,
818 	   typename _Allocator, typename _ExtractKey, typename _Equal,
819 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
820 	   bool __chc, bool __cit, bool __uk>
821     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey,
822 			_Equal, _H1, _H2, _Hash, _RehashPolicy,
823 			__chc, __cit, __uk>::_Node*
824     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
825 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
826     _M_find_node(_Node* __p, const key_type& __k,
827 		typename _Hashtable::_Hash_code_type __code) const
828     {
829       for (; __p; __p = __p->_M_next)
830 	if (this->_M_compare(__k, __code, __p))
831 	  return __p;
832       return 0;
833     }
834 
835   // Insert v in bucket n (assumes no element with its key already present).
836   template<typename _Key, typename _Value,
837 	   typename _Allocator, typename _ExtractKey, typename _Equal,
838 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
839 	   bool __chc, bool __cit, bool __uk>
840     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
841 			_H1, _H2, _Hash, _RehashPolicy,
842 			__chc, __cit, __uk>::iterator
843     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
844 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
845     _M_insert_bucket(const value_type& __v, size_type __n,
846 		    typename _Hashtable::_Hash_code_type __code)
847     {
848       std::pair<bool, std::size_t> __do_rehash
849 	= _M_rehash_policy._M_need_rehash(_M_bucket_count,
850 					  _M_element_count, 1);
851 
852       // Allocate the new node before doing the rehash so that we don't
853       // do a rehash if the allocation throws.
854       _Node* __new_node = _M_allocate_node(__v);
855 
856       __try
857 	{
858 	  if (__do_rehash.first)
859 	    {
860 	      const key_type& __k = this->_M_extract(__v);
861 	      __n = this->_M_bucket_index(__k, __code, __do_rehash.second);
862 	      _M_rehash(__do_rehash.second);
863 	    }
864 
865 	  __new_node->_M_next = _M_buckets[__n];
866 	  this->_M_store_code(__new_node, __code);
867 	  _M_buckets[__n] = __new_node;
868 	  ++_M_element_count;
869 	  return iterator(__new_node, _M_buckets + __n);
870 	}
871       __catch(...)
872 	{
873 	  _M_deallocate_node(__new_node);
874 	  __throw_exception_again;
875 	}
876     }
877 
878   // Insert v if no element with its key is already present.
879   template<typename _Key, typename _Value,
880 	   typename _Allocator, typename _ExtractKey, typename _Equal,
881 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
882 	   bool __chc, bool __cit, bool __uk>
883     std::pair<typename _Hashtable<_Key, _Value, _Allocator,
884 				  _ExtractKey, _Equal, _H1,
885 				  _H2, _Hash, _RehashPolicy,
886 				  __chc, __cit, __uk>::iterator, bool>
887     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
888 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
889   _M_insert(const value_type& __v, std::tr1::true_type)
890     {
891       const key_type& __k = this->_M_extract(__v);
892       typename _Hashtable::_Hash_code_type __code = this->_M_hash_code(__k);
893       size_type __n = this->_M_bucket_index(__k, __code, _M_bucket_count);
894 
895       if (_Node* __p = _M_find_node(_M_buckets[__n], __k, __code))
896 	return std::make_pair(iterator(__p, _M_buckets + __n), false);
897       return std::make_pair(_M_insert_bucket(__v, __n, __code), true);
898     }
899 
900   // Insert v unconditionally.
901   template<typename _Key, typename _Value,
902 	   typename _Allocator, typename _ExtractKey, typename _Equal,
903 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
904 	   bool __chc, bool __cit, bool __uk>
905     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
906 			_H1, _H2, _Hash, _RehashPolicy,
907 			__chc, __cit, __uk>::iterator
908     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
909 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
910     _M_insert(const value_type& __v, std::tr1::false_type)
911     {
912       std::pair<bool, std::size_t> __do_rehash
913 	= _M_rehash_policy._M_need_rehash(_M_bucket_count,
914 					  _M_element_count, 1);
915       if (__do_rehash.first)
916 	_M_rehash(__do_rehash.second);
917 
918       const key_type& __k = this->_M_extract(__v);
919       typename _Hashtable::_Hash_code_type __code = this->_M_hash_code(__k);
920       size_type __n = this->_M_bucket_index(__k, __code, _M_bucket_count);
921 
922       // First find the node, avoid leaking new_node if compare throws.
923       _Node* __prev = _M_find_node(_M_buckets[__n], __k, __code);
924       _Node* __new_node = _M_allocate_node(__v);
925 
926       if (__prev)
927 	{
928 	  __new_node->_M_next = __prev->_M_next;
929 	  __prev->_M_next = __new_node;
930 	}
931       else
932 	{
933 	  __new_node->_M_next = _M_buckets[__n];
934 	  _M_buckets[__n] = __new_node;
935 	}
936       this->_M_store_code(__new_node, __code);
937 
938       ++_M_element_count;
939       return iterator(__new_node, _M_buckets + __n);
940     }
941 
942   // For erase(iterator) and erase(const_iterator).
943   template<typename _Key, typename _Value,
944 	   typename _Allocator, typename _ExtractKey, typename _Equal,
945 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
946 	   bool __chc, bool __cit, bool __uk>
947     void
948     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
949 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
950     _M_erase_node(_Node* __p, _Node** __b)
951     {
952       _Node* __cur = *__b;
953       if (__cur == __p)
954 	*__b = __cur->_M_next;
955       else
956 	{
957 	  _Node* __next = __cur->_M_next;
958 	  while (__next != __p)
959 	    {
960 	      __cur = __next;
961 	      __next = __cur->_M_next;
962 	    }
963 	  __cur->_M_next = __next->_M_next;
964 	}
965 
966       _M_deallocate_node(__p);
967       --_M_element_count;
968     }
969 
970   template<typename _Key, typename _Value,
971 	   typename _Allocator, typename _ExtractKey, typename _Equal,
972 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
973 	   bool __chc, bool __cit, bool __uk>
974     template<typename _InputIterator>
975       void
976       _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
977 		 _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
978       insert(_InputIterator __first, _InputIterator __last)
979       {
980 	size_type __n_elt = __detail::__distance_fw(__first, __last);
981 	std::pair<bool, std::size_t> __do_rehash
982 	  = _M_rehash_policy._M_need_rehash(_M_bucket_count,
983 					    _M_element_count, __n_elt);
984 	if (__do_rehash.first)
985 	  _M_rehash(__do_rehash.second);
986 
987 	for (; __first != __last; ++__first)
988 	  this->insert(*__first);
989       }
990 
991   template<typename _Key, typename _Value,
992 	   typename _Allocator, typename _ExtractKey, typename _Equal,
993 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
994 	   bool __chc, bool __cit, bool __uk>
995     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
996 			_H1, _H2, _Hash, _RehashPolicy,
997 			__chc, __cit, __uk>::iterator
998     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
999 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
1000     erase(iterator __it)
1001     {
1002       iterator __result = __it;
1003       ++__result;
1004       _M_erase_node(__it._M_cur_node, __it._M_cur_bucket);
1005       return __result;
1006     }
1007 
1008   template<typename _Key, typename _Value,
1009 	   typename _Allocator, typename _ExtractKey, typename _Equal,
1010 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1011 	   bool __chc, bool __cit, bool __uk>
1012     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1013 			_H1, _H2, _Hash, _RehashPolicy,
1014 			__chc, __cit, __uk>::const_iterator
1015     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1016 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
1017     erase(const_iterator __it)
1018     {
1019       const_iterator __result = __it;
1020       ++__result;
1021       _M_erase_node(__it._M_cur_node, __it._M_cur_bucket);
1022       return __result;
1023     }
1024 
1025   template<typename _Key, typename _Value,
1026 	   typename _Allocator, typename _ExtractKey, typename _Equal,
1027 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1028 	   bool __chc, bool __cit, bool __uk>
1029     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1030 			_H1, _H2, _Hash, _RehashPolicy,
1031 			__chc, __cit, __uk>::size_type
1032     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1033 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
1034     erase(const key_type& __k)
1035     {
1036       typename _Hashtable::_Hash_code_type __code = this->_M_hash_code(__k);
1037       std::size_t __n = this->_M_bucket_index(__k, __code, _M_bucket_count);
1038       size_type __result = 0;
1039 
1040       _Node** __slot = _M_buckets + __n;
1041       while (*__slot && !this->_M_compare(__k, __code, *__slot))
1042 	__slot = &((*__slot)->_M_next);
1043 
1044       _Node** __saved_slot = 0;
1045       while (*__slot && this->_M_compare(__k, __code, *__slot))
1046 	{
1047 	  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1048 	  // 526. Is it undefined if a function in the standard changes
1049 	  // in parameters?
1050 	  if (&this->_M_extract((*__slot)->_M_v) != &__k)
1051 	    {
1052 	      _Node* __p = *__slot;
1053 	      *__slot = __p->_M_next;
1054 	      _M_deallocate_node(__p);
1055 	      --_M_element_count;
1056 	      ++__result;
1057 	    }
1058 	  else
1059 	    {
1060 	      __saved_slot = __slot;
1061 	      __slot = &((*__slot)->_M_next);
1062 	    }
1063 	}
1064 
1065       if (__saved_slot)
1066 	{
1067 	  _Node* __p = *__saved_slot;
1068 	  *__saved_slot = __p->_M_next;
1069 	  _M_deallocate_node(__p);
1070 	  --_M_element_count;
1071 	  ++__result;
1072 	}
1073 
1074       return __result;
1075     }
1076 
1077   // ??? This could be optimized by taking advantage of the bucket
1078   // structure, but it's not clear that it's worth doing.  It probably
1079   // wouldn't even be an optimization unless the load factor is large.
1080   template<typename _Key, typename _Value,
1081 	   typename _Allocator, typename _ExtractKey, typename _Equal,
1082 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1083 	   bool __chc, bool __cit, bool __uk>
1084     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1085 			_H1, _H2, _Hash, _RehashPolicy,
1086 			__chc, __cit, __uk>::iterator
1087     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1088 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
1089     erase(iterator __first, iterator __last)
1090     {
1091       while (__first != __last)
1092 	__first = this->erase(__first);
1093       return __last;
1094     }
1095 
1096   template<typename _Key, typename _Value,
1097 	   typename _Allocator, typename _ExtractKey, typename _Equal,
1098 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1099 	   bool __chc, bool __cit, bool __uk>
1100     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1101 			_H1, _H2, _Hash, _RehashPolicy,
1102 			__chc, __cit, __uk>::const_iterator
1103     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1104 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
1105     erase(const_iterator __first, const_iterator __last)
1106     {
1107       while (__first != __last)
1108 	__first = this->erase(__first);
1109       return __last;
1110     }
1111 
1112   template<typename _Key, typename _Value,
1113 	   typename _Allocator, typename _ExtractKey, typename _Equal,
1114 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1115 	   bool __chc, bool __cit, bool __uk>
1116     void
1117     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1118 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
1119     clear()
1120     {
1121       _M_deallocate_nodes(_M_buckets, _M_bucket_count);
1122       _M_element_count = 0;
1123     }
1124 
1125   template<typename _Key, typename _Value,
1126 	   typename _Allocator, typename _ExtractKey, typename _Equal,
1127 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1128 	   bool __chc, bool __cit, bool __uk>
1129     void
1130     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1131 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
1132     rehash(size_type __n)
1133     {
1134       _M_rehash(std::max(_M_rehash_policy._M_next_bkt(__n),
1135 			 _M_rehash_policy._M_bkt_for_elements(_M_element_count
1136 							      + 1)));
1137     }
1138 
1139   template<typename _Key, typename _Value,
1140 	   typename _Allocator, typename _ExtractKey, typename _Equal,
1141 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1142 	   bool __chc, bool __cit, bool __uk>
1143     void
1144     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1145 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
1146     _M_rehash(size_type __n)
1147     {
1148       _Node** __new_array = _M_allocate_buckets(__n);
1149       __try
1150 	{
1151 	  for (size_type __i = 0; __i < _M_bucket_count; ++__i)
1152 	    while (_Node* __p = _M_buckets[__i])
1153 	      {
1154 		std::size_t __new_index = this->_M_bucket_index(__p, __n);
1155 		_M_buckets[__i] = __p->_M_next;
1156 		__p->_M_next = __new_array[__new_index];
1157 		__new_array[__new_index] = __p;
1158 	      }
1159 	  _M_deallocate_buckets(_M_buckets, _M_bucket_count);
1160 	  _M_bucket_count = __n;
1161 	  _M_buckets = __new_array;
1162 	}
1163       __catch(...)
1164 	{
1165 	  // A failure here means that a hash function threw an exception.
1166 	  // We can't restore the previous state without calling the hash
1167 	  // function again, so the only sensible recovery is to delete
1168 	  // everything.
1169 	  _M_deallocate_nodes(__new_array, __n);
1170 	  _M_deallocate_buckets(__new_array, __n);
1171 	  _M_deallocate_nodes(_M_buckets, _M_bucket_count);
1172 	  _M_element_count = 0;
1173 	  __throw_exception_again;
1174 	}
1175     }
1176 } // namespace tr1
1177 
1178 _GLIBCXX_END_NAMESPACE_VERSION
1179 } // namespace std
1180 
1181 #endif // _GLIBCXX_TR1_HASHTABLE_H
1182