1 // TR1 hashtable.h header -*- C++ -*-
2 
3 // Copyright (C) 2007-2020 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 #include <ext/alloc_traits.h>
38 
_GLIBCXX_VISIBILITY(default)39 namespace std _GLIBCXX_VISIBILITY(default)
40 {
41 _GLIBCXX_BEGIN_NAMESPACE_VERSION
42 
43 namespace tr1
44 {
45   // Class template _Hashtable, class definition.
46 
47   // Meaning of class template _Hashtable's template parameters
48 
49   // _Key and _Value: arbitrary CopyConstructible types.
50 
51   // _Allocator: an allocator type ([lib.allocator.requirements]) whose
52   // value type is Value.  As a conforming extension, we allow for
53   // value type != Value.
54 
55   // _ExtractKey: function object that takes a object of type Value
56   // and returns a value of type _Key.
57 
58   // _Equal: function object that takes two objects of type k and returns
59   // a bool-like value that is true if the two objects are considered equal.
60 
61   // _H1: the hash function.  A unary function object with argument type
62   // Key and result type size_t.  Return values should be distributed
63   // over the entire range [0, numeric_limits<size_t>:::max()].
64 
65   // _H2: the range-hashing function (in the terminology of Tavori and
66   // Dreizin).  A binary function object whose argument types and result
67   // type are all size_t.  Given arguments r and N, the return value is
68   // in the range [0, N).
69 
70   // _Hash: the ranged hash function (Tavori and Dreizin). A binary function
71   // whose argument types are _Key and size_t and whose result type is
72   // size_t.  Given arguments k and N, the return value is in the range
73   // [0, N).  Default: hash(k, N) = h2(h1(k), N).  If _Hash is anything other
74   // than the default, _H1 and _H2 are ignored.
75 
76   // _RehashPolicy: Policy class with three members, all of which govern
77   // the bucket count. _M_next_bkt(n) returns a bucket count no smaller
78   // than n.  _M_bkt_for_elements(n) returns a bucket count appropriate
79   // for an element count of n.  _M_need_rehash(n_bkt, n_elt, n_ins)
80   // determines whether, if the current bucket count is n_bkt and the
81   // current element count is n_elt, we need to increase the bucket
82   // count.  If so, returns make_pair(true, n), where n is the new
83   // bucket count.  If not, returns make_pair(false, <anything>).
84 
85   // ??? Right now it is hard-wired that the number of buckets never
86   // shrinks.  Should we allow _RehashPolicy to change that?
87 
88   // __cache_hash_code: bool.  true if we store the value of the hash
89   // function along with the value.  This is a time-space tradeoff.
90   // Storing it may improve lookup speed by reducing the number of times
91   // we need to call the Equal function.
92 
93   // __constant_iterators: bool.  true if iterator and const_iterator are
94   // both constant iterator types.  This is true for unordered_set and
95   // unordered_multiset, false for unordered_map and unordered_multimap.
96 
97   // __unique_keys: bool.  true if the return value of _Hashtable::count(k)
98   // is always at most one, false if it may be an arbitrary number.  This
99   // true for unordered_set and unordered_map, false for unordered_multiset
100   // and unordered_multimap.
101 
102   template<typename _Key, typename _Value, typename _Allocator,
103 	   typename _ExtractKey, typename _Equal,
104 	   typename _H1, typename _H2, typename _Hash,
105 	   typename _RehashPolicy,
106 	   bool __cache_hash_code,
107 	   bool __constant_iterators,
108 	   bool __unique_keys>
109     class _Hashtable
110     : public __detail::_Rehash_base<_RehashPolicy,
111 				    _Hashtable<_Key, _Value, _Allocator,
112 					       _ExtractKey,
113 					       _Equal, _H1, _H2, _Hash,
114 					       _RehashPolicy,
115 					       __cache_hash_code,
116 					       __constant_iterators,
117 					       __unique_keys> >,
118       public __detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Equal,
119 				       _H1, _H2, _Hash, __cache_hash_code>,
120       public __detail::_Map_base<_Key, _Value, _ExtractKey, __unique_keys,
121 				 _Hashtable<_Key, _Value, _Allocator,
122 					    _ExtractKey,
123 					    _Equal, _H1, _H2, _Hash,
124 					    _RehashPolicy,
125 					    __cache_hash_code,
126 					    __constant_iterators,
127 					    __unique_keys> >
128     {
129       typedef __gnu_cxx::__alloc_traits<_Allocator> _Alloc_traits;
130 
131     public:
132       typedef _Allocator                                  allocator_type;
133       typedef _Value                                      value_type;
134       typedef _Key                                        key_type;
135       typedef _Equal                                      key_equal;
136       // mapped_type, if present, comes from _Map_base.
137       // hasher, if present, comes from _Hash_code_base.
138       typedef typename _Allocator::difference_type        difference_type;
139       typedef typename _Allocator::size_type              size_type;
140       typedef typename _Alloc_traits::pointer             pointer;
141       typedef typename _Alloc_traits::const_pointer       const_pointer;
142       typedef typename _Alloc_traits::reference           reference;
143       typedef typename _Alloc_traits::const_reference     const_reference;
144 
145       typedef __detail::_Node_iterator<value_type, __constant_iterators,
146 				       __cache_hash_code>
147 							  local_iterator;
148       typedef __detail::_Node_const_iterator<value_type,
149 					     __constant_iterators,
150 					     __cache_hash_code>
151 							  const_local_iterator;
152 
153       typedef __detail::_Hashtable_iterator<value_type, __constant_iterators,
154 					    __cache_hash_code>
155 							  iterator;
156       typedef __detail::_Hashtable_const_iterator<value_type,
157 						  __constant_iterators,
158 						  __cache_hash_code>
159 							  const_iterator;
160 
161       template<typename _Key2, typename _Value2, typename _Ex2, bool __unique2,
162 	       typename _Hashtable2>
163 	friend struct __detail::_Map_base;
164 
165     private:
166       typedef __detail::_Hash_node<_Value, __cache_hash_code> _Node;
167       typedef typename _Alloc_traits::template rebind<_Node>::other
168 						      _Node_allocator_type;
169       typedef typename _Alloc_traits::template rebind<_Node*>::other
170 						      _Bucket_allocator_type;
171 
172       typedef typename _Alloc_traits::template rebind<_Value>::other
173 						      _Value_allocator_type;
174 
175       _Node_allocator_type   _M_node_allocator;
176       _Node**                _M_buckets;
177       size_type              _M_bucket_count;
178       size_type              _M_element_count;
179       _RehashPolicy          _M_rehash_policy;
180 
181       _Node*
182       _M_allocate_node(const value_type& __v);
183 
184       void
185       _M_deallocate_node(_Node* __n);
186 
187       void
188       _M_deallocate_nodes(_Node**, size_type);
189 
190       _Node**
191       _M_allocate_buckets(size_type __n);
192 
193       void
194       _M_deallocate_buckets(_Node**, size_type __n);
195 
196     public:
197       // Constructor, destructor, assignment, swap
198       _Hashtable(size_type __bucket_hint,
199 		 const _H1&, const _H2&, const _Hash&,
200 		 const _Equal&, const _ExtractKey&,
201 		 const allocator_type&);
202 
203       template<typename _InputIterator>
204 	_Hashtable(_InputIterator __first, _InputIterator __last,
205 		   size_type __bucket_hint,
206 		   const _H1&, const _H2&, const _Hash&,
207 		   const _Equal&, const _ExtractKey&,
208 		   const allocator_type&);
209 
210       _Hashtable(const _Hashtable&);
211 
212       _Hashtable&
213       operator=(const _Hashtable&);
214 
215       ~_Hashtable();
216 
217       void swap(_Hashtable&);
218 
219       // Basic container operations
220       iterator
221       begin()
222       {
223 	iterator __i(_M_buckets);
224 	if (!__i._M_cur_node)
225 	  __i._M_incr_bucket();
226 	return __i;
227       }
228 
229       const_iterator
230       begin() const
231       {
232 	const_iterator __i(_M_buckets);
233 	if (!__i._M_cur_node)
234 	  __i._M_incr_bucket();
235 	return __i;
236       }
237 
238       iterator
239       end()
240       { return iterator(_M_buckets + _M_bucket_count); }
241 
242       const_iterator
243       end() const
244       { return const_iterator(_M_buckets + _M_bucket_count); }
245 
246       size_type
247       size() const
248       { return _M_element_count; }
249 
250       _GLIBCXX_NODISCARD bool
251       empty() const
252       { return size() == 0; }
253 
254       allocator_type
255       get_allocator() const
256       { return allocator_type(_M_node_allocator); }
257 
258       _Value_allocator_type
259       _M_get_Value_allocator() const
260       { return _Value_allocator_type(_M_node_allocator); }
261 
262       size_type
263       max_size() const
264       {
265 	typedef __gnu_cxx::__alloc_traits<_Node_allocator_type> _Traits;
266 	return _Traits::max_size(_M_node_allocator);
267       }
268 
269       // Observers
270       key_equal
271       key_eq() const
272       { return this->_M_eq; }
273 
274       // hash_function, if present, comes from _Hash_code_base.
275 
276       // Bucket operations
277       size_type
278       bucket_count() const
279       { return _M_bucket_count; }
280 
281       size_type
282       max_bucket_count() const
283       { return max_size(); }
284 
285       size_type
286       bucket_size(size_type __n) const
287       { return std::distance(begin(__n), end(__n)); }
288 
289       size_type
290       bucket(const key_type& __k) const
291       {
292 	return this->_M_bucket_index(__k, this->_M_hash_code(__k),
293 				     bucket_count());
294       }
295 
296       local_iterator
297       begin(size_type __n)
298       { return local_iterator(_M_buckets[__n]); }
299 
300       local_iterator
301       end(size_type)
302       { return local_iterator(0); }
303 
304       const_local_iterator
305       begin(size_type __n) const
306       { return const_local_iterator(_M_buckets[__n]); }
307 
308       const_local_iterator
309       end(size_type) const
310       { return const_local_iterator(0); }
311 
312       float
313       load_factor() const
314       {
315 	return static_cast<float>(size()) / static_cast<float>(bucket_count());
316       }
317 
318       // max_load_factor, if present, comes from _Rehash_base.
319 
320       // Generalization of max_load_factor.  Extension, not found in TR1.  Only
321       // useful if _RehashPolicy is something other than the default.
322       const _RehashPolicy&
323       __rehash_policy() const
324       { return _M_rehash_policy; }
325 
326       void
327       __rehash_policy(const _RehashPolicy&);
328 
329       // Lookup.
330       iterator
331       find(const key_type& __k);
332 
333       const_iterator
334       find(const key_type& __k) const;
335 
336       size_type
337       count(const key_type& __k) const;
338 
339       std::pair<iterator, iterator>
340       equal_range(const key_type& __k);
341 
342       std::pair<const_iterator, const_iterator>
343       equal_range(const key_type& __k) const;
344 
345     private:			// Find, insert and erase helper functions
346       // ??? This dispatching is a workaround for the fact that we don't
347       // have partial specialization of member templates; it would be
348       // better to just specialize insert on __unique_keys.  There may be a
349       // cleaner workaround.
350       typedef typename __gnu_cxx::__conditional_type<__unique_keys,
351 		       	    std::pair<iterator, bool>, iterator>::__type
352 	_Insert_Return_Type;
353 
354       typedef typename __gnu_cxx::__conditional_type<__unique_keys,
355 					  std::_Select1st<_Insert_Return_Type>,
356 				  	  std::_Identity<_Insert_Return_Type>
357 				   >::__type
358 	_Insert_Conv_Type;
359 
360       _Node*
361       _M_find_node(_Node*, const key_type&,
362 		   typename _Hashtable::_Hash_code_type) const;
363 
364       iterator
365       _M_insert_bucket(const value_type&, size_type,
366 		       typename _Hashtable::_Hash_code_type);
367 
368       std::pair<iterator, bool>
369       _M_insert(const value_type&, std::tr1::true_type);
370 
371       iterator
372       _M_insert(const value_type&, std::tr1::false_type);
373 
374       void
375       _M_erase_node(_Node*, _Node**);
376 
377     public:
378       // Insert and erase
379       _Insert_Return_Type
380       insert(const value_type& __v)
381       { return _M_insert(__v, std::tr1::integral_constant<bool,
382 			 __unique_keys>()); }
383 
384       iterator
385       insert(iterator, const value_type& __v)
386       { return iterator(_Insert_Conv_Type()(this->insert(__v))); }
387 
388       const_iterator
389       insert(const_iterator, const value_type& __v)
390       { return const_iterator(_Insert_Conv_Type()(this->insert(__v))); }
391 
392       template<typename _InputIterator>
393 	void
394 	insert(_InputIterator __first, _InputIterator __last);
395 
396       iterator
397       erase(iterator);
398 
399       const_iterator
400       erase(const_iterator);
401 
402       size_type
403       erase(const key_type&);
404 
405       iterator
406       erase(iterator, iterator);
407 
408       const_iterator
409       erase(const_iterator, const_iterator);
410 
411       void
412       clear();
413 
414       // Set number of buckets to be appropriate for container of n element.
415       void rehash(size_type __n);
416 
417     private:
418       // Unconditionally change size of bucket array to n.
419       void _M_rehash(size_type __n);
420     };
421 
422 
423   // Definitions of class template _Hashtable's out-of-line member functions.
424   template<typename _Key, typename _Value,
425 	   typename _Allocator, typename _ExtractKey, typename _Equal,
426 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
427 	   bool __chc, bool __cit, bool __uk>
428     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
429 			_H1, _H2, _Hash, _RehashPolicy,
430 			__chc, __cit, __uk>::_Node*
431     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
432 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
433     _M_allocate_node(const value_type& __v)
434     {
435       _Node* __n = _M_node_allocator.allocate(1);
436       __try
437 	{
438 	  _Value_allocator_type __a = _M_get_Value_allocator();
439 	  typedef __gnu_cxx::__alloc_traits<_Value_allocator_type> _Traits;
440 	  _Traits::construct(__a, &__n->_M_v, __v);
441 	  __n->_M_next = 0;
442 	  return __n;
443 	}
444       __catch(...)
445 	{
446 	  _M_node_allocator.deallocate(__n, 1);
447 	  __throw_exception_again;
448 	}
449     }
450 
451   template<typename _Key, typename _Value,
452 	   typename _Allocator, typename _ExtractKey, typename _Equal,
453 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
454 	   bool __chc, bool __cit, bool __uk>
455     void
456     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
457 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
458     _M_deallocate_node(_Node* __n)
459     {
460       _Value_allocator_type __a = _M_get_Value_allocator();
461       typedef __gnu_cxx::__alloc_traits<_Value_allocator_type> _Traits;
462       _Traits::destroy(__a, &__n->_M_v);
463       _M_node_allocator.deallocate(__n, 1);
464     }
465 
466   template<typename _Key, typename _Value,
467 	   typename _Allocator, typename _ExtractKey, typename _Equal,
468 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
469 	   bool __chc, bool __cit, bool __uk>
470     void
471     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
472 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
473     _M_deallocate_nodes(_Node** __array, size_type __n)
474     {
475       for (size_type __i = 0; __i < __n; ++__i)
476 	{
477 	  _Node* __p = __array[__i];
478 	  while (__p)
479 	    {
480 	      _Node* __tmp = __p;
481 	      __p = __p->_M_next;
482 	      _M_deallocate_node(__tmp);
483 	    }
484 	  __array[__i] = 0;
485 	}
486     }
487 
488   template<typename _Key, typename _Value,
489 	   typename _Allocator, typename _ExtractKey, typename _Equal,
490 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
491 	   bool __chc, bool __cit, bool __uk>
492     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
493 			_H1, _H2, _Hash, _RehashPolicy,
494 			__chc, __cit, __uk>::_Node**
495     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
496 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
497     _M_allocate_buckets(size_type __n)
498     {
499       _Bucket_allocator_type __alloc(_M_node_allocator);
500 
501       // We allocate one extra bucket to hold a sentinel, an arbitrary
502       // non-null pointer.  Iterator increment relies on this.
503       _Node** __p = __alloc.allocate(__n + 1);
504       std::fill(__p, __p + __n, (_Node*) 0);
505       __p[__n] = reinterpret_cast<_Node*>(0x1000);
506       return __p;
507     }
508 
509   template<typename _Key, typename _Value,
510 	   typename _Allocator, typename _ExtractKey, typename _Equal,
511 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
512 	   bool __chc, bool __cit, bool __uk>
513     void
514     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
515 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
516     _M_deallocate_buckets(_Node** __p, size_type __n)
517     {
518       _Bucket_allocator_type __alloc(_M_node_allocator);
519       __alloc.deallocate(__p, __n + 1);
520     }
521 
522   template<typename _Key, typename _Value,
523 	   typename _Allocator, typename _ExtractKey, typename _Equal,
524 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
525 	   bool __chc, bool __cit, bool __uk>
526     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
527 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
528     _Hashtable(size_type __bucket_hint,
529 	       const _H1& __h1, const _H2& __h2, const _Hash& __h,
530 	       const _Equal& __eq, const _ExtractKey& __exk,
531 	       const allocator_type& __a)
532     : __detail::_Rehash_base<_RehashPolicy, _Hashtable>(),
533       __detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Equal,
534 				_H1, _H2, _Hash, __chc>(__exk, __eq,
535 							__h1, __h2, __h),
536       __detail::_Map_base<_Key, _Value, _ExtractKey, __uk, _Hashtable>(),
537       _M_node_allocator(__a),
538       _M_bucket_count(0),
539       _M_element_count(0),
540       _M_rehash_policy()
541     {
542       _M_bucket_count = _M_rehash_policy._M_next_bkt(__bucket_hint);
543       _M_buckets = _M_allocate_buckets(_M_bucket_count);
544     }
545 
546   template<typename _Key, typename _Value,
547 	   typename _Allocator, typename _ExtractKey, typename _Equal,
548 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
549 	   bool __chc, bool __cit, bool __uk>
550     template<typename _InputIterator>
551       _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
552 		 _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
553       _Hashtable(_InputIterator __f, _InputIterator __l,
554 		 size_type __bucket_hint,
555 		 const _H1& __h1, const _H2& __h2, const _Hash& __h,
556 		 const _Equal& __eq, const _ExtractKey& __exk,
557 		 const allocator_type& __a)
558       : __detail::_Rehash_base<_RehashPolicy, _Hashtable>(),
559 	__detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Equal,
560 				  _H1, _H2, _Hash, __chc>(__exk, __eq,
561 							  __h1, __h2, __h),
562 	__detail::_Map_base<_Key, _Value, _ExtractKey, __uk, _Hashtable>(),
563 	_M_node_allocator(__a),
564 	_M_bucket_count(0),
565 	_M_element_count(0),
566 	_M_rehash_policy()
567       {
568 	_M_bucket_count = std::max(_M_rehash_policy._M_next_bkt(__bucket_hint),
569 				   _M_rehash_policy.
570 				   _M_bkt_for_elements(__detail::
571 						       __distance_fw(__f,
572 								     __l)));
573 	_M_buckets = _M_allocate_buckets(_M_bucket_count);
574 	__try
575 	  {
576 	    for (; __f != __l; ++__f)
577 	      this->insert(*__f);
578 	  }
579 	__catch(...)
580 	  {
581 	    clear();
582 	    _M_deallocate_buckets(_M_buckets, _M_bucket_count);
583 	    __throw_exception_again;
584 	  }
585       }
586 
587   template<typename _Key, typename _Value,
588 	   typename _Allocator, typename _ExtractKey, typename _Equal,
589 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
590 	   bool __chc, bool __cit, bool __uk>
591     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
592 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
593     _Hashtable(const _Hashtable& __ht)
594     : __detail::_Rehash_base<_RehashPolicy, _Hashtable>(__ht),
595       __detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Equal,
596 				_H1, _H2, _Hash, __chc>(__ht),
597       __detail::_Map_base<_Key, _Value, _ExtractKey, __uk, _Hashtable>(__ht),
598       _M_node_allocator(__ht._M_node_allocator),
599       _M_bucket_count(__ht._M_bucket_count),
600       _M_element_count(__ht._M_element_count),
601       _M_rehash_policy(__ht._M_rehash_policy)
602     {
603       _M_buckets = _M_allocate_buckets(_M_bucket_count);
604       __try
605 	{
606 	  for (size_type __i = 0; __i < __ht._M_bucket_count; ++__i)
607 	    {
608 	      _Node* __n = __ht._M_buckets[__i];
609 	      _Node** __tail = _M_buckets + __i;
610 	      while (__n)
611 		{
612 		  *__tail = _M_allocate_node(__n->_M_v);
613 		  this->_M_copy_code(*__tail, __n);
614 		  __tail = &((*__tail)->_M_next);
615 		  __n = __n->_M_next;
616 		}
617 	    }
618 	}
619       __catch(...)
620 	{
621 	  clear();
622 	  _M_deallocate_buckets(_M_buckets, _M_bucket_count);
623 	  __throw_exception_again;
624 	}
625     }
626 
627   template<typename _Key, typename _Value,
628 	   typename _Allocator, typename _ExtractKey, typename _Equal,
629 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
630 	   bool __chc, bool __cit, bool __uk>
631     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
632 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>&
633     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
634 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
635     operator=(const _Hashtable& __ht)
636     {
637       _Hashtable __tmp(__ht);
638       this->swap(__tmp);
639       return *this;
640     }
641 
642   template<typename _Key, typename _Value,
643 	   typename _Allocator, typename _ExtractKey, typename _Equal,
644 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
645 	   bool __chc, bool __cit, bool __uk>
646     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
647 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
648     ~_Hashtable()
649     {
650       clear();
651       _M_deallocate_buckets(_M_buckets, _M_bucket_count);
652     }
653 
654   template<typename _Key, typename _Value,
655 	   typename _Allocator, typename _ExtractKey, typename _Equal,
656 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
657 	   bool __chc, bool __cit, bool __uk>
658     void
659     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
660 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
661     swap(_Hashtable& __x)
662     {
663       // The only base class with member variables is hash_code_base.  We
664       // define _Hash_code_base::_M_swap because different specializations
665       // have different members.
666       __detail::_Hash_code_base<_Key, _Value, _ExtractKey, _Equal,
667 	_H1, _H2, _Hash, __chc>::_M_swap(__x);
668 
669       // _GLIBCXX_RESOLVE_LIB_DEFECTS
670       // 431. Swapping containers with unequal allocators.
671       std::__alloc_swap<_Node_allocator_type>::_S_do_it(_M_node_allocator,
672 							__x._M_node_allocator);
673 
674       std::swap(_M_rehash_policy, __x._M_rehash_policy);
675       std::swap(_M_buckets, __x._M_buckets);
676       std::swap(_M_bucket_count, __x._M_bucket_count);
677       std::swap(_M_element_count, __x._M_element_count);
678     }
679 
680   template<typename _Key, typename _Value,
681 	   typename _Allocator, typename _ExtractKey, typename _Equal,
682 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
683 	   bool __chc, bool __cit, bool __uk>
684     void
685     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
686 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
687     __rehash_policy(const _RehashPolicy& __pol)
688     {
689       _M_rehash_policy = __pol;
690       size_type __n_bkt = __pol._M_bkt_for_elements(_M_element_count);
691       if (__n_bkt > _M_bucket_count)
692 	_M_rehash(__n_bkt);
693     }
694 
695   template<typename _Key, typename _Value,
696 	   typename _Allocator, typename _ExtractKey, typename _Equal,
697 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
698 	   bool __chc, bool __cit, bool __uk>
699     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
700 			_H1, _H2, _Hash, _RehashPolicy,
701 			__chc, __cit, __uk>::iterator
702     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
703 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
704     find(const key_type& __k)
705     {
706       typename _Hashtable::_Hash_code_type __code = this->_M_hash_code(__k);
707       std::size_t __n = this->_M_bucket_index(__k, __code, _M_bucket_count);
708       _Node* __p = _M_find_node(_M_buckets[__n], __k, __code);
709       return __p ? iterator(__p, _M_buckets + __n) : this->end();
710     }
711 
712   template<typename _Key, typename _Value,
713 	   typename _Allocator, typename _ExtractKey, typename _Equal,
714 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
715 	   bool __chc, bool __cit, bool __uk>
716     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
717 			_H1, _H2, _Hash, _RehashPolicy,
718 			__chc, __cit, __uk>::const_iterator
719     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
720 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
721     find(const key_type& __k) const
722     {
723       typename _Hashtable::_Hash_code_type __code = this->_M_hash_code(__k);
724       std::size_t __n = this->_M_bucket_index(__k, __code, _M_bucket_count);
725       _Node* __p = _M_find_node(_M_buckets[__n], __k, __code);
726       return __p ? const_iterator(__p, _M_buckets + __n) : this->end();
727     }
728 
729   template<typename _Key, typename _Value,
730 	   typename _Allocator, typename _ExtractKey, typename _Equal,
731 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
732 	   bool __chc, bool __cit, bool __uk>
733     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
734 			_H1, _H2, _Hash, _RehashPolicy,
735 			__chc, __cit, __uk>::size_type
736     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
737 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
738     count(const key_type& __k) const
739     {
740       typename _Hashtable::_Hash_code_type __code = this->_M_hash_code(__k);
741       std::size_t __n = this->_M_bucket_index(__k, __code, _M_bucket_count);
742       std::size_t __result = 0;
743       for (_Node* __p = _M_buckets[__n]; __p; __p = __p->_M_next)
744 	if (this->_M_compare(__k, __code, __p))
745 	  ++__result;
746       return __result;
747     }
748 
749   template<typename _Key, typename _Value,
750 	   typename _Allocator, typename _ExtractKey, typename _Equal,
751 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
752 	   bool __chc, bool __cit, bool __uk>
753     std::pair<typename _Hashtable<_Key, _Value, _Allocator,
754 				  _ExtractKey, _Equal, _H1,
755 				  _H2, _Hash, _RehashPolicy,
756 				  __chc, __cit, __uk>::iterator,
757 	      typename _Hashtable<_Key, _Value, _Allocator,
758 				  _ExtractKey, _Equal, _H1,
759 				  _H2, _Hash, _RehashPolicy,
760 				  __chc, __cit, __uk>::iterator>
761     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
762 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
763     equal_range(const key_type& __k)
764     {
765       typename _Hashtable::_Hash_code_type __code = this->_M_hash_code(__k);
766       std::size_t __n = this->_M_bucket_index(__k, __code, _M_bucket_count);
767       _Node** __head = _M_buckets + __n;
768       _Node* __p = _M_find_node(*__head, __k, __code);
769 
770       if (__p)
771 	{
772 	  _Node* __p1 = __p->_M_next;
773 	  for (; __p1; __p1 = __p1->_M_next)
774 	    if (!this->_M_compare(__k, __code, __p1))
775 	      break;
776 
777 	  iterator __first(__p, __head);
778 	  iterator __last(__p1, __head);
779 	  if (!__p1)
780 	    __last._M_incr_bucket();
781 	  return std::make_pair(__first, __last);
782 	}
783       else
784 	return std::make_pair(this->end(), this->end());
785     }
786 
787   template<typename _Key, typename _Value,
788 	   typename _Allocator, typename _ExtractKey, typename _Equal,
789 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
790 	   bool __chc, bool __cit, bool __uk>
791     std::pair<typename _Hashtable<_Key, _Value, _Allocator,
792 				  _ExtractKey, _Equal, _H1,
793 				  _H2, _Hash, _RehashPolicy,
794 				  __chc, __cit, __uk>::const_iterator,
795 	      typename _Hashtable<_Key, _Value, _Allocator,
796 				  _ExtractKey, _Equal, _H1,
797 				  _H2, _Hash, _RehashPolicy,
798 				  __chc, __cit, __uk>::const_iterator>
799     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
800 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
801     equal_range(const key_type& __k) const
802     {
803       typename _Hashtable::_Hash_code_type __code = this->_M_hash_code(__k);
804       std::size_t __n = this->_M_bucket_index(__k, __code, _M_bucket_count);
805       _Node** __head = _M_buckets + __n;
806       _Node* __p = _M_find_node(*__head, __k, __code);
807 
808       if (__p)
809 	{
810 	  _Node* __p1 = __p->_M_next;
811 	  for (; __p1; __p1 = __p1->_M_next)
812 	    if (!this->_M_compare(__k, __code, __p1))
813 	      break;
814 
815 	  const_iterator __first(__p, __head);
816 	  const_iterator __last(__p1, __head);
817 	  if (!__p1)
818 	    __last._M_incr_bucket();
819 	  return std::make_pair(__first, __last);
820 	}
821       else
822 	return std::make_pair(this->end(), this->end());
823     }
824 
825   // Find the node whose key compares equal to k, beginning the search
826   // at p (usually the head of a bucket).  Return zero if no node is found.
827   template<typename _Key, typename _Value,
828 	   typename _Allocator, typename _ExtractKey, typename _Equal,
829 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
830 	   bool __chc, bool __cit, bool __uk>
831     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey,
832 			_Equal, _H1, _H2, _Hash, _RehashPolicy,
833 			__chc, __cit, __uk>::_Node*
834     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
835 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
836     _M_find_node(_Node* __p, const key_type& __k,
837 		typename _Hashtable::_Hash_code_type __code) const
838     {
839       for (; __p; __p = __p->_M_next)
840 	if (this->_M_compare(__k, __code, __p))
841 	  return __p;
842       return 0;
843     }
844 
845   // Insert v in bucket n (assumes no element with its key already present).
846   template<typename _Key, typename _Value,
847 	   typename _Allocator, typename _ExtractKey, typename _Equal,
848 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
849 	   bool __chc, bool __cit, bool __uk>
850     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
851 			_H1, _H2, _Hash, _RehashPolicy,
852 			__chc, __cit, __uk>::iterator
853     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
854 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
855     _M_insert_bucket(const value_type& __v, size_type __n,
856 		    typename _Hashtable::_Hash_code_type __code)
857     {
858       std::pair<bool, std::size_t> __do_rehash
859 	= _M_rehash_policy._M_need_rehash(_M_bucket_count,
860 					  _M_element_count, 1);
861 
862       // Allocate the new node before doing the rehash so that we don't
863       // do a rehash if the allocation throws.
864       _Node* __new_node = _M_allocate_node(__v);
865 
866       __try
867 	{
868 	  if (__do_rehash.first)
869 	    {
870 	      const key_type& __k = this->_M_extract(__v);
871 	      __n = this->_M_bucket_index(__k, __code, __do_rehash.second);
872 	      _M_rehash(__do_rehash.second);
873 	    }
874 
875 	  __new_node->_M_next = _M_buckets[__n];
876 	  this->_M_store_code(__new_node, __code);
877 	  _M_buckets[__n] = __new_node;
878 	  ++_M_element_count;
879 	  return iterator(__new_node, _M_buckets + __n);
880 	}
881       __catch(...)
882 	{
883 	  _M_deallocate_node(__new_node);
884 	  __throw_exception_again;
885 	}
886     }
887 
888   // Insert v if no element with its key is already present.
889   template<typename _Key, typename _Value,
890 	   typename _Allocator, typename _ExtractKey, typename _Equal,
891 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
892 	   bool __chc, bool __cit, bool __uk>
893     std::pair<typename _Hashtable<_Key, _Value, _Allocator,
894 				  _ExtractKey, _Equal, _H1,
895 				  _H2, _Hash, _RehashPolicy,
896 				  __chc, __cit, __uk>::iterator, bool>
897     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
898 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
899   _M_insert(const value_type& __v, std::tr1::true_type)
900     {
901       const key_type& __k = this->_M_extract(__v);
902       typename _Hashtable::_Hash_code_type __code = this->_M_hash_code(__k);
903       size_type __n = this->_M_bucket_index(__k, __code, _M_bucket_count);
904 
905       if (_Node* __p = _M_find_node(_M_buckets[__n], __k, __code))
906 	return std::make_pair(iterator(__p, _M_buckets + __n), false);
907       return std::make_pair(_M_insert_bucket(__v, __n, __code), true);
908     }
909 
910   // Insert v unconditionally.
911   template<typename _Key, typename _Value,
912 	   typename _Allocator, typename _ExtractKey, typename _Equal,
913 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
914 	   bool __chc, bool __cit, bool __uk>
915     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
916 			_H1, _H2, _Hash, _RehashPolicy,
917 			__chc, __cit, __uk>::iterator
918     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
919 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
920     _M_insert(const value_type& __v, std::tr1::false_type)
921     {
922       std::pair<bool, std::size_t> __do_rehash
923 	= _M_rehash_policy._M_need_rehash(_M_bucket_count,
924 					  _M_element_count, 1);
925       if (__do_rehash.first)
926 	_M_rehash(__do_rehash.second);
927 
928       const key_type& __k = this->_M_extract(__v);
929       typename _Hashtable::_Hash_code_type __code = this->_M_hash_code(__k);
930       size_type __n = this->_M_bucket_index(__k, __code, _M_bucket_count);
931 
932       // First find the node, avoid leaking new_node if compare throws.
933       _Node* __prev = _M_find_node(_M_buckets[__n], __k, __code);
934       _Node* __new_node = _M_allocate_node(__v);
935 
936       if (__prev)
937 	{
938 	  __new_node->_M_next = __prev->_M_next;
939 	  __prev->_M_next = __new_node;
940 	}
941       else
942 	{
943 	  __new_node->_M_next = _M_buckets[__n];
944 	  _M_buckets[__n] = __new_node;
945 	}
946       this->_M_store_code(__new_node, __code);
947 
948       ++_M_element_count;
949       return iterator(__new_node, _M_buckets + __n);
950     }
951 
952   // For erase(iterator) and erase(const_iterator).
953   template<typename _Key, typename _Value,
954 	   typename _Allocator, typename _ExtractKey, typename _Equal,
955 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
956 	   bool __chc, bool __cit, bool __uk>
957     void
958     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
959 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
960     _M_erase_node(_Node* __p, _Node** __b)
961     {
962       _Node* __cur = *__b;
963       if (__cur == __p)
964 	*__b = __cur->_M_next;
965       else
966 	{
967 	  _Node* __next = __cur->_M_next;
968 	  while (__next != __p)
969 	    {
970 	      __cur = __next;
971 	      __next = __cur->_M_next;
972 	    }
973 	  __cur->_M_next = __next->_M_next;
974 	}
975 
976       _M_deallocate_node(__p);
977       --_M_element_count;
978     }
979 
980   template<typename _Key, typename _Value,
981 	   typename _Allocator, typename _ExtractKey, typename _Equal,
982 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
983 	   bool __chc, bool __cit, bool __uk>
984     template<typename _InputIterator>
985       void
986       _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
987 		 _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
988       insert(_InputIterator __first, _InputIterator __last)
989       {
990 	size_type __n_elt = __detail::__distance_fw(__first, __last);
991 	std::pair<bool, std::size_t> __do_rehash
992 	  = _M_rehash_policy._M_need_rehash(_M_bucket_count,
993 					    _M_element_count, __n_elt);
994 	if (__do_rehash.first)
995 	  _M_rehash(__do_rehash.second);
996 
997 	for (; __first != __last; ++__first)
998 	  this->insert(*__first);
999       }
1000 
1001   template<typename _Key, typename _Value,
1002 	   typename _Allocator, typename _ExtractKey, typename _Equal,
1003 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1004 	   bool __chc, bool __cit, bool __uk>
1005     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1006 			_H1, _H2, _Hash, _RehashPolicy,
1007 			__chc, __cit, __uk>::iterator
1008     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1009 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
1010     erase(iterator __it)
1011     {
1012       iterator __result = __it;
1013       ++__result;
1014       _M_erase_node(__it._M_cur_node, __it._M_cur_bucket);
1015       return __result;
1016     }
1017 
1018   template<typename _Key, typename _Value,
1019 	   typename _Allocator, typename _ExtractKey, typename _Equal,
1020 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1021 	   bool __chc, bool __cit, bool __uk>
1022     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1023 			_H1, _H2, _Hash, _RehashPolicy,
1024 			__chc, __cit, __uk>::const_iterator
1025     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1026 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
1027     erase(const_iterator __it)
1028     {
1029       const_iterator __result = __it;
1030       ++__result;
1031       _M_erase_node(__it._M_cur_node, __it._M_cur_bucket);
1032       return __result;
1033     }
1034 
1035   template<typename _Key, typename _Value,
1036 	   typename _Allocator, typename _ExtractKey, typename _Equal,
1037 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1038 	   bool __chc, bool __cit, bool __uk>
1039     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1040 			_H1, _H2, _Hash, _RehashPolicy,
1041 			__chc, __cit, __uk>::size_type
1042     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1043 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
1044     erase(const key_type& __k)
1045     {
1046       typename _Hashtable::_Hash_code_type __code = this->_M_hash_code(__k);
1047       std::size_t __n = this->_M_bucket_index(__k, __code, _M_bucket_count);
1048       size_type __result = 0;
1049 
1050       _Node** __slot = _M_buckets + __n;
1051       while (*__slot && !this->_M_compare(__k, __code, *__slot))
1052 	__slot = &((*__slot)->_M_next);
1053 
1054       _Node** __saved_slot = 0;
1055       while (*__slot && this->_M_compare(__k, __code, *__slot))
1056 	{
1057 	  // _GLIBCXX_RESOLVE_LIB_DEFECTS
1058 	  // 526. Is it undefined if a function in the standard changes
1059 	  // in parameters?
1060 	  if (&this->_M_extract((*__slot)->_M_v) != &__k)
1061 	    {
1062 	      _Node* __p = *__slot;
1063 	      *__slot = __p->_M_next;
1064 	      _M_deallocate_node(__p);
1065 	      --_M_element_count;
1066 	      ++__result;
1067 	    }
1068 	  else
1069 	    {
1070 	      __saved_slot = __slot;
1071 	      __slot = &((*__slot)->_M_next);
1072 	    }
1073 	}
1074 
1075       if (__saved_slot)
1076 	{
1077 	  _Node* __p = *__saved_slot;
1078 	  *__saved_slot = __p->_M_next;
1079 	  _M_deallocate_node(__p);
1080 	  --_M_element_count;
1081 	  ++__result;
1082 	}
1083 
1084       return __result;
1085     }
1086 
1087   // ??? This could be optimized by taking advantage of the bucket
1088   // structure, but it's not clear that it's worth doing.  It probably
1089   // wouldn't even be an optimization unless the load factor is large.
1090   template<typename _Key, typename _Value,
1091 	   typename _Allocator, typename _ExtractKey, typename _Equal,
1092 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1093 	   bool __chc, bool __cit, bool __uk>
1094     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1095 			_H1, _H2, _Hash, _RehashPolicy,
1096 			__chc, __cit, __uk>::iterator
1097     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1098 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
1099     erase(iterator __first, iterator __last)
1100     {
1101       while (__first != __last)
1102 	__first = this->erase(__first);
1103       return __last;
1104     }
1105 
1106   template<typename _Key, typename _Value,
1107 	   typename _Allocator, typename _ExtractKey, typename _Equal,
1108 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1109 	   bool __chc, bool __cit, bool __uk>
1110     typename _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1111 			_H1, _H2, _Hash, _RehashPolicy,
1112 			__chc, __cit, __uk>::const_iterator
1113     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1114 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
1115     erase(const_iterator __first, const_iterator __last)
1116     {
1117       while (__first != __last)
1118 	__first = this->erase(__first);
1119       return __last;
1120     }
1121 
1122   template<typename _Key, typename _Value,
1123 	   typename _Allocator, typename _ExtractKey, typename _Equal,
1124 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1125 	   bool __chc, bool __cit, bool __uk>
1126     void
1127     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1128 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
1129     clear()
1130     {
1131       _M_deallocate_nodes(_M_buckets, _M_bucket_count);
1132       _M_element_count = 0;
1133     }
1134 
1135   template<typename _Key, typename _Value,
1136 	   typename _Allocator, typename _ExtractKey, typename _Equal,
1137 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1138 	   bool __chc, bool __cit, bool __uk>
1139     void
1140     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1141 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
1142     rehash(size_type __n)
1143     {
1144       _M_rehash(std::max(_M_rehash_policy._M_next_bkt(__n),
1145 			 _M_rehash_policy._M_bkt_for_elements(_M_element_count
1146 							      + 1)));
1147     }
1148 
1149   template<typename _Key, typename _Value,
1150 	   typename _Allocator, typename _ExtractKey, typename _Equal,
1151 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1152 	   bool __chc, bool __cit, bool __uk>
1153     void
1154     _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
1155 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
1156     _M_rehash(size_type __n)
1157     {
1158       _Node** __new_array = _M_allocate_buckets(__n);
1159       __try
1160 	{
1161 	  for (size_type __i = 0; __i < _M_bucket_count; ++__i)
1162 	    while (_Node* __p = _M_buckets[__i])
1163 	      {
1164 		std::size_t __new_index = this->_M_bucket_index(__p, __n);
1165 		_M_buckets[__i] = __p->_M_next;
1166 		__p->_M_next = __new_array[__new_index];
1167 		__new_array[__new_index] = __p;
1168 	      }
1169 	  _M_deallocate_buckets(_M_buckets, _M_bucket_count);
1170 	  _M_bucket_count = __n;
1171 	  _M_buckets = __new_array;
1172 	}
1173       __catch(...)
1174 	{
1175 	  // A failure here means that a hash function threw an exception.
1176 	  // We can't restore the previous state without calling the hash
1177 	  // function again, so the only sensible recovery is to delete
1178 	  // everything.
1179 	  _M_deallocate_nodes(__new_array, __n);
1180 	  _M_deallocate_buckets(__new_array, __n);
1181 	  _M_deallocate_nodes(_M_buckets, _M_bucket_count);
1182 	  _M_element_count = 0;
1183 	  __throw_exception_again;
1184 	}
1185     }
1186 } // namespace tr1
1187 
1188 _GLIBCXX_END_NAMESPACE_VERSION
1189 } // namespace std
1190 
1191 #endif // _GLIBCXX_TR1_HASHTABLE_H
1192