1 // Vector implementation -*- C++ -*-
2 
3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
4 // Free Software Foundation, Inc.
5 //
6 // This file is part of the GNU ISO C++ Library.  This library is free
7 // software; you can redistribute it and/or modify it under the
8 // terms of the GNU General Public License as published by the
9 // Free Software Foundation; either version 2, or (at your option)
10 // any later version.
11 
12 // This library is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 // GNU General Public License for more details.
16 
17 // You should have received a copy of the GNU General Public License along
18 // with this library; see the file COPYING.  If not, write to the Free
19 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
20 // USA.
21 
22 // As a special exception, you may use this file as part of a free software
23 // library without restriction.  Specifically, if other files instantiate
24 // templates or use macros or inline functions from this file, or you compile
25 // this file and link it with other files to produce an executable, this
26 // file does not by itself cause the resulting executable to be covered by
27 // the GNU General Public License.  This exception does not however
28 // invalidate any other reasons why the executable file might be covered by
29 // the GNU General Public License.
30 
31 /*
32  *
33  * Copyright (c) 1994
34  * Hewlett-Packard Company
35  *
36  * Permission to use, copy, modify, distribute and sell this software
37  * and its documentation for any purpose is hereby granted without fee,
38  * provided that the above copyright notice appear in all copies and
39  * that both that copyright notice and this permission notice appear
40  * in supporting documentation.  Hewlett-Packard Company makes no
41  * representations about the suitability of this software for any
42  * purpose.  It is provided "as is" without express or implied warranty.
43  *
44  *
45  * Copyright (c) 1996
46  * Silicon Graphics Computer Systems, Inc.
47  *
48  * Permission to use, copy, modify, distribute and sell this software
49  * and its documentation for any purpose is hereby granted without fee,
50  * provided that the above copyright notice appear in all copies and
51  * that both that copyright notice and this permission notice appear
52  * in supporting documentation.  Silicon Graphics makes no
53  * representations about the suitability of this  software for any
54  * purpose.  It is provided "as is" without express or implied warranty.
55  */
56 
57 /** @file stl_vector.h
58  *  This is an internal header file, included by other library headers.
59  *  You should not attempt to use it directly.
60  */
61 
62 #ifndef _VECTOR_H
63 #define _VECTOR_H 1
64 
65 #include <bits/stl_iterator_base_funcs.h>
66 #include <bits/functexcept.h>
67 #include <bits/concept_check.h>
68 
69 _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD)
70 
71   /**
72    *  @if maint
73    *  See bits/stl_deque.h's _Deque_base for an explanation.
74    *  @endif
75   */
76   template<typename _Tp, typename _Alloc>
77     struct _Vector_base
78     {
79       typedef typename _Alloc::template rebind<_Tp>::other _Tp_alloc_type;
80 
81       struct _Vector_impl
82       : public _Tp_alloc_type
83       {
84 	_Tp*           _M_start;
85 	_Tp*           _M_finish;
86 	_Tp*           _M_end_of_storage;
87 	_Vector_impl(_Tp_alloc_type const& __a)
88 	: _Tp_alloc_type(__a), _M_start(0), _M_finish(0), _M_end_of_storage(0)
89 	{ }
90       };
91 
92     public:
93       typedef _Alloc allocator_type;
94 
95       _Tp_alloc_type&
96       _M_get_Tp_allocator()
97       { return *static_cast<_Tp_alloc_type*>(&this->_M_impl); }
98 
99       const _Tp_alloc_type&
100       _M_get_Tp_allocator() const
101       { return *static_cast<const _Tp_alloc_type*>(&this->_M_impl); }
102 
103       allocator_type
104       get_allocator() const
105       { return allocator_type(_M_get_Tp_allocator()); }
106 
107       _Vector_base(const allocator_type& __a)
108       : _M_impl(__a)
109       { }
110 
111       _Vector_base(size_t __n, const allocator_type& __a)
112       : _M_impl(__a)
113       {
114 	this->_M_impl._M_start = this->_M_allocate(__n);
115 	this->_M_impl._M_finish = this->_M_impl._M_start;
116 	this->_M_impl._M_end_of_storage = this->_M_impl._M_start + __n;
117       }
118 
119       ~_Vector_base()
120       { _M_deallocate(this->_M_impl._M_start, this->_M_impl._M_end_of_storage
121 		      - this->_M_impl._M_start); }
122 
123     public:
124       _Vector_impl _M_impl;
125 
126       _Tp*
127       _M_allocate(size_t __n)
128       { return _M_impl.allocate(__n); }
129 
130       void
131       _M_deallocate(_Tp* __p, size_t __n)
132       {
133 	if (__p)
134 	  _M_impl.deallocate(__p, __n);
135       }
136     };
137 
138 
139   /**
140    *  @brief A standard container which offers fixed time access to
141    *  individual elements in any order.
142    *
143    *  @ingroup Containers
144    *  @ingroup Sequences
145    *
146    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
147    *  <a href="tables.html#66">reversible container</a>, and a
148    *  <a href="tables.html#67">sequence</a>, including the
149    *  <a href="tables.html#68">optional sequence requirements</a> with the
150    *  %exception of @c push_front and @c pop_front.
151    *
152    *  In some terminology a %vector can be described as a dynamic
153    *  C-style array, it offers fast and efficient access to individual
154    *  elements in any order and saves the user from worrying about
155    *  memory and size allocation.  Subscripting ( @c [] ) access is
156    *  also provided as with C-style arrays.
157   */
158   template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
159     class vector : protected _Vector_base<_Tp, _Alloc>
160     {
161       // Concept requirements.
162       typedef typename _Alloc::value_type                _Alloc_value_type;
163       __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
164       __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept)
165 
166       typedef _Vector_base<_Tp, _Alloc>			 _Base;
167       typedef vector<_Tp, _Alloc>			 vector_type;
168       typedef typename _Base::_Tp_alloc_type		 _Tp_alloc_type;
169 
170     public:
171       typedef _Tp					 value_type;
172       typedef typename _Tp_alloc_type::pointer           pointer;
173       typedef typename _Tp_alloc_type::const_pointer     const_pointer;
174       typedef typename _Tp_alloc_type::reference         reference;
175       typedef typename _Tp_alloc_type::const_reference   const_reference;
176       typedef __gnu_cxx::__normal_iterator<pointer, vector_type> iterator;
177       typedef __gnu_cxx::__normal_iterator<const_pointer, vector_type>
178       const_iterator;
179       typedef std::reverse_iterator<const_iterator>  const_reverse_iterator;
180       typedef std::reverse_iterator<iterator>		 reverse_iterator;
181       typedef size_t					 size_type;
182       typedef ptrdiff_t					 difference_type;
183       typedef _Alloc                        		 allocator_type;
184 
185     protected:
186       using _Base::_M_allocate;
187       using _Base::_M_deallocate;
188       using _Base::_M_impl;
189       using _Base::_M_get_Tp_allocator;
190 
191     public:
192       // [23.2.4.1] construct/copy/destroy
193       // (assign() and get_allocator() are also listed in this section)
194       /**
195        *  @brief  Default constructor creates no elements.
196        */
197       explicit
198       vector(const allocator_type& __a = allocator_type())
199       : _Base(__a)
200       { }
201 
202       /**
203        *  @brief  Create a %vector with copies of an exemplar element.
204        *  @param  n  The number of elements to initially create.
205        *  @param  value  An element to copy.
206        *
207        *  This constructor fills the %vector with @a n copies of @a value.
208        */
209       explicit
210       vector(size_type __n, const value_type& __value = value_type(),
211 	     const allocator_type& __a = allocator_type())
212       : _Base(__n, __a)
213       {
214 	std::__uninitialized_fill_n_a(this->_M_impl._M_start, __n, __value,
215 				      _M_get_Tp_allocator());
216 	this->_M_impl._M_finish = this->_M_impl._M_start + __n;
217       }
218 
219       /**
220        *  @brief  %Vector copy constructor.
221        *  @param  x  A %vector of identical element and allocator types.
222        *
223        *  The newly-created %vector uses a copy of the allocation
224        *  object used by @a x.  All the elements of @a x are copied,
225        *  but any extra memory in
226        *  @a x (for fast expansion) will not be copied.
227        */
228       vector(const vector& __x)
229       : _Base(__x.size(), __x._M_get_Tp_allocator())
230       { this->_M_impl._M_finish =
231 	  std::__uninitialized_copy_a(__x.begin(), __x.end(),
232 				      this->_M_impl._M_start,
233 				      _M_get_Tp_allocator());
234       }
235 
236       /**
237        *  @brief  Builds a %vector from a range.
238        *  @param  first  An input iterator.
239        *  @param  last  An input iterator.
240        *
241        *  Create a %vector consisting of copies of the elements from
242        *  [first,last).
243        *
244        *  If the iterators are forward, bidirectional, or
245        *  random-access, then this will call the elements' copy
246        *  constructor N times (where N is distance(first,last)) and do
247        *  no memory reallocation.  But if only input iterators are
248        *  used, then this will do at most 2N calls to the copy
249        *  constructor, and logN memory reallocations.
250        */
251       template<typename _InputIterator>
252         vector(_InputIterator __first, _InputIterator __last,
253 	       const allocator_type& __a = allocator_type())
254 	: _Base(__a)
255         {
256 	  // Check whether it's an integral type.  If so, it's not an iterator.
257 	  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
258 	  _M_initialize_dispatch(__first, __last, _Integral());
259 	}
260 
261       /**
262        *  The dtor only erases the elements, and note that if the
263        *  elements themselves are pointers, the pointed-to memory is
264        *  not touched in any way.  Managing the pointer is the user's
265        *  responsibilty.
266        */
267       ~vector()
268       { std::_Destroy(this->_M_impl._M_start, this->_M_impl._M_finish,
269 		      _M_get_Tp_allocator()); }
270 
271       /**
272        *  @brief  %Vector assignment operator.
273        *  @param  x  A %vector of identical element and allocator types.
274        *
275        *  All the elements of @a x are copied, but any extra memory in
276        *  @a x (for fast expansion) will not be copied.  Unlike the
277        *  copy constructor, the allocator object is not copied.
278        */
279       vector&
280       operator=(const vector& __x);
281 
282       /**
283        *  @brief  Assigns a given value to a %vector.
284        *  @param  n  Number of elements to be assigned.
285        *  @param  val  Value to be assigned.
286        *
287        *  This function fills a %vector with @a n copies of the given
288        *  value.  Note that the assignment completely changes the
289        *  %vector and that the resulting %vector's size is the same as
290        *  the number of elements assigned.  Old data may be lost.
291        */
292       void
293       assign(size_type __n, const value_type& __val)
294       { _M_fill_assign(__n, __val); }
295 
296       /**
297        *  @brief  Assigns a range to a %vector.
298        *  @param  first  An input iterator.
299        *  @param  last   An input iterator.
300        *
301        *  This function fills a %vector with copies of the elements in the
302        *  range [first,last).
303        *
304        *  Note that the assignment completely changes the %vector and
305        *  that the resulting %vector's size is the same as the number
306        *  of elements assigned.  Old data may be lost.
307        */
308       template<typename _InputIterator>
309         void
310         assign(_InputIterator __first, _InputIterator __last)
311         {
312 	  // Check whether it's an integral type.  If so, it's not an iterator.
313 	  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
314 	  _M_assign_dispatch(__first, __last, _Integral());
315 	}
316 
317       /// Get a copy of the memory allocation object.
318       using _Base::get_allocator;
319 
320       // iterators
321       /**
322        *  Returns a read/write iterator that points to the first
323        *  element in the %vector.  Iteration is done in ordinary
324        *  element order.
325        */
326       iterator
327       begin()
328       { return iterator(this->_M_impl._M_start); }
329 
330       /**
331        *  Returns a read-only (constant) iterator that points to the
332        *  first element in the %vector.  Iteration is done in ordinary
333        *  element order.
334        */
335       const_iterator
336       begin() const
337       { return const_iterator(this->_M_impl._M_start); }
338 
339       /**
340        *  Returns a read/write iterator that points one past the last
341        *  element in the %vector.  Iteration is done in ordinary
342        *  element order.
343        */
344       iterator
345       end()
346       { return iterator(this->_M_impl._M_finish); }
347 
348       /**
349        *  Returns a read-only (constant) iterator that points one past
350        *  the last element in the %vector.  Iteration is done in
351        *  ordinary element order.
352        */
353       const_iterator
354       end() const
355       { return const_iterator(this->_M_impl._M_finish); }
356 
357       /**
358        *  Returns a read/write reverse iterator that points to the
359        *  last element in the %vector.  Iteration is done in reverse
360        *  element order.
361        */
362       reverse_iterator
363       rbegin()
364       { return reverse_iterator(end()); }
365 
366       /**
367        *  Returns a read-only (constant) reverse iterator that points
368        *  to the last element in the %vector.  Iteration is done in
369        *  reverse element order.
370        */
371       const_reverse_iterator
372       rbegin() const
373       { return const_reverse_iterator(end()); }
374 
375       /**
376        *  Returns a read/write reverse iterator that points to one
377        *  before the first element in the %vector.  Iteration is done
378        *  in reverse element order.
379        */
380       reverse_iterator
381       rend()
382       { return reverse_iterator(begin()); }
383 
384       /**
385        *  Returns a read-only (constant) reverse iterator that points
386        *  to one before the first element in the %vector.  Iteration
387        *  is done in reverse element order.
388        */
389       const_reverse_iterator
390       rend() const
391       { return const_reverse_iterator(begin()); }
392 
393       // [23.2.4.2] capacity
394       /**  Returns the number of elements in the %vector.  */
395       size_type
396       size() const
397       { return size_type(this->_M_impl._M_finish - this->_M_impl._M_start); }
398 
399       /**  Returns the size() of the largest possible %vector.  */
400       size_type
401       max_size() const
402       { return _M_get_Tp_allocator().max_size(); }
403 
404       /**
405        *  @brief  Resizes the %vector to the specified number of elements.
406        *  @param  new_size  Number of elements the %vector should contain.
407        *  @param  x  Data with which new elements should be populated.
408        *
409        *  This function will %resize the %vector to the specified
410        *  number of elements.  If the number is smaller than the
411        *  %vector's current size the %vector is truncated, otherwise
412        *  the %vector is extended and new elements are populated with
413        *  given data.
414        */
415       void
416       resize(size_type __new_size, value_type __x = value_type())
417       {
418 	if (__new_size < size())
419 	  _M_erase_at_end(this->_M_impl._M_start + __new_size);
420 	else
421 	  insert(end(), __new_size - size(), __x);
422       }
423 
424       /**
425        *  Returns the total number of elements that the %vector can
426        *  hold before needing to allocate more memory.
427        */
428       size_type
429       capacity() const
430       { return size_type(this->_M_impl._M_end_of_storage
431 			 - this->_M_impl._M_start); }
432 
433       /**
434        *  Returns true if the %vector is empty.  (Thus begin() would
435        *  equal end().)
436        */
437       bool
438       empty() const
439       { return begin() == end(); }
440 
441       /**
442        *  @brief  Attempt to preallocate enough memory for specified number of
443        *          elements.
444        *  @param  n  Number of elements required.
445        *  @throw  std::length_error  If @a n exceeds @c max_size().
446        *
447        *  This function attempts to reserve enough memory for the
448        *  %vector to hold the specified number of elements.  If the
449        *  number requested is more than max_size(), length_error is
450        *  thrown.
451        *
452        *  The advantage of this function is that if optimal code is a
453        *  necessity and the user can determine the number of elements
454        *  that will be required, the user can reserve the memory in
455        *  %advance, and thus prevent a possible reallocation of memory
456        *  and copying of %vector data.
457        */
458       void
459       reserve(size_type __n);
460 
461       // element access
462       /**
463        *  @brief  Subscript access to the data contained in the %vector.
464        *  @param n The index of the element for which data should be
465        *  accessed.
466        *  @return  Read/write reference to data.
467        *
468        *  This operator allows for easy, array-style, data access.
469        *  Note that data access with this operator is unchecked and
470        *  out_of_range lookups are not defined. (For checked lookups
471        *  see at().)
472        */
473       reference
474       operator[](size_type __n)
475       { return *(this->_M_impl._M_start + __n); }
476 
477       /**
478        *  @brief  Subscript access to the data contained in the %vector.
479        *  @param n The index of the element for which data should be
480        *  accessed.
481        *  @return  Read-only (constant) reference to data.
482        *
483        *  This operator allows for easy, array-style, data access.
484        *  Note that data access with this operator is unchecked and
485        *  out_of_range lookups are not defined. (For checked lookups
486        *  see at().)
487        */
488       const_reference
489       operator[](size_type __n) const
490       { return *(this->_M_impl._M_start + __n); }
491 
492     protected:
493       /// @if maint Safety check used only from at().  @endif
494       void
495       _M_range_check(size_type __n) const
496       {
497 	if (__n >= this->size())
498 	  __throw_out_of_range(__N("vector::_M_range_check"));
499       }
500 
501     public:
502       /**
503        *  @brief  Provides access to the data contained in the %vector.
504        *  @param n The index of the element for which data should be
505        *  accessed.
506        *  @return  Read/write reference to data.
507        *  @throw  std::out_of_range  If @a n is an invalid index.
508        *
509        *  This function provides for safer data access.  The parameter
510        *  is first checked that it is in the range of the vector.  The
511        *  function throws out_of_range if the check fails.
512        */
513       reference
514       at(size_type __n)
515       {
516 	_M_range_check(__n);
517 	return (*this)[__n];
518       }
519 
520       /**
521        *  @brief  Provides access to the data contained in the %vector.
522        *  @param n The index of the element for which data should be
523        *  accessed.
524        *  @return  Read-only (constant) reference to data.
525        *  @throw  std::out_of_range  If @a n is an invalid index.
526        *
527        *  This function provides for safer data access.  The parameter
528        *  is first checked that it is in the range of the vector.  The
529        *  function throws out_of_range if the check fails.
530        */
531       const_reference
532       at(size_type __n) const
533       {
534 	_M_range_check(__n);
535 	return (*this)[__n];
536       }
537 
538       /**
539        *  Returns a read/write reference to the data at the first
540        *  element of the %vector.
541        */
542       reference
543       front()
544       { return *begin(); }
545 
546       /**
547        *  Returns a read-only (constant) reference to the data at the first
548        *  element of the %vector.
549        */
550       const_reference
551       front() const
552       { return *begin(); }
553 
554       /**
555        *  Returns a read/write reference to the data at the last
556        *  element of the %vector.
557        */
558       reference
559       back()
560       { return *(end() - 1); }
561 
562       /**
563        *  Returns a read-only (constant) reference to the data at the
564        *  last element of the %vector.
565        */
566       const_reference
567       back() const
568       { return *(end() - 1); }
569 
570       // _GLIBCXX_RESOLVE_LIB_DEFECTS
571       // DR 464. Suggestion for new member functions in standard containers.
572       // data access
573       /**
574        *   Returns a pointer such that [data(), data() + size()) is a valid
575        *   range.  For a non-empty %vector, data() == &front().
576        */
577       pointer
578       data()
579       { return pointer(this->_M_impl._M_start); }
580 
581       const_pointer
582       data() const
583       { return const_pointer(this->_M_impl._M_start); }
584 
585       // [23.2.4.3] modifiers
586       /**
587        *  @brief  Add data to the end of the %vector.
588        *  @param  x  Data to be added.
589        *
590        *  This is a typical stack operation.  The function creates an
591        *  element at the end of the %vector and assigns the given data
592        *  to it.  Due to the nature of a %vector this operation can be
593        *  done in constant time if the %vector has preallocated space
594        *  available.
595        */
596       void
597       push_back(const value_type& __x)
598       {
599 	if (this->_M_impl._M_finish != this->_M_impl._M_end_of_storage)
600 	  {
601 	    this->_M_impl.construct(this->_M_impl._M_finish, __x);
602 	    ++this->_M_impl._M_finish;
603 	  }
604 	else
605 	  _M_insert_aux(end(), __x);
606       }
607 
608       /**
609        *  @brief  Removes last element.
610        *
611        *  This is a typical stack operation. It shrinks the %vector by one.
612        *
613        *  Note that no data is returned, and if the last element's
614        *  data is needed, it should be retrieved before pop_back() is
615        *  called.
616        */
617       void
618       pop_back()
619       {
620 	--this->_M_impl._M_finish;
621 	this->_M_impl.destroy(this->_M_impl._M_finish);
622       }
623 
624       /**
625        *  @brief  Inserts given value into %vector before specified iterator.
626        *  @param  position  An iterator into the %vector.
627        *  @param  x  Data to be inserted.
628        *  @return  An iterator that points to the inserted data.
629        *
630        *  This function will insert a copy of the given value before
631        *  the specified location.  Note that this kind of operation
632        *  could be expensive for a %vector and if it is frequently
633        *  used the user should consider using std::list.
634        */
635       iterator
636       insert(iterator __position, const value_type& __x);
637 
638       /**
639        *  @brief  Inserts a number of copies of given data into the %vector.
640        *  @param  position  An iterator into the %vector.
641        *  @param  n  Number of elements to be inserted.
642        *  @param  x  Data to be inserted.
643        *
644        *  This function will insert a specified number of copies of
645        *  the given data before the location specified by @a position.
646        *
647        *  Note that this kind of operation could be expensive for a
648        *  %vector and if it is frequently used the user should
649        *  consider using std::list.
650        */
651       void
652       insert(iterator __position, size_type __n, const value_type& __x)
653       { _M_fill_insert(__position, __n, __x); }
654 
655       /**
656        *  @brief  Inserts a range into the %vector.
657        *  @param  position  An iterator into the %vector.
658        *  @param  first  An input iterator.
659        *  @param  last   An input iterator.
660        *
661        *  This function will insert copies of the data in the range
662        *  [first,last) into the %vector before the location specified
663        *  by @a pos.
664        *
665        *  Note that this kind of operation could be expensive for a
666        *  %vector and if it is frequently used the user should
667        *  consider using std::list.
668        */
669       template<typename _InputIterator>
670         void
671         insert(iterator __position, _InputIterator __first,
672 	       _InputIterator __last)
673         {
674 	  // Check whether it's an integral type.  If so, it's not an iterator.
675 	  typedef typename std::__is_integer<_InputIterator>::__type _Integral;
676 	  _M_insert_dispatch(__position, __first, __last, _Integral());
677 	}
678 
679       /**
680        *  @brief  Remove element at given position.
681        *  @param  position  Iterator pointing to element to be erased.
682        *  @return  An iterator pointing to the next element (or end()).
683        *
684        *  This function will erase the element at the given position and thus
685        *  shorten the %vector by one.
686        *
687        *  Note This operation could be expensive and if it is
688        *  frequently used the user should consider using std::list.
689        *  The user is also cautioned that this function only erases
690        *  the element, and that if the element is itself a pointer,
691        *  the pointed-to memory is not touched in any way.  Managing
692        *  the pointer is the user's responsibilty.
693        */
694       iterator
695       erase(iterator __position);
696 
697       /**
698        *  @brief  Remove a range of elements.
699        *  @param  first  Iterator pointing to the first element to be erased.
700        *  @param  last  Iterator pointing to one past the last element to be
701        *                erased.
702        *  @return  An iterator pointing to the element pointed to by @a last
703        *           prior to erasing (or end()).
704        *
705        *  This function will erase the elements in the range [first,last) and
706        *  shorten the %vector accordingly.
707        *
708        *  Note This operation could be expensive and if it is
709        *  frequently used the user should consider using std::list.
710        *  The user is also cautioned that this function only erases
711        *  the elements, and that if the elements themselves are
712        *  pointers, the pointed-to memory is not touched in any way.
713        *  Managing the pointer is the user's responsibilty.
714        */
715       iterator
716       erase(iterator __first, iterator __last);
717 
718       /**
719        *  @brief  Swaps data with another %vector.
720        *  @param  x  A %vector of the same element and allocator types.
721        *
722        *  This exchanges the elements between two vectors in constant time.
723        *  (Three pointers, so it should be quite fast.)
724        *  Note that the global std::swap() function is specialized such that
725        *  std::swap(v1,v2) will feed to this function.
726        */
727       void
728       swap(vector& __x)
729       {
730 	std::swap(this->_M_impl._M_start, __x._M_impl._M_start);
731 	std::swap(this->_M_impl._M_finish, __x._M_impl._M_finish);
732 	std::swap(this->_M_impl._M_end_of_storage,
733 		  __x._M_impl._M_end_of_storage);
734 
735 	// _GLIBCXX_RESOLVE_LIB_DEFECTS
736 	// 431. Swapping containers with unequal allocators.
737 	std::__alloc_swap<_Tp_alloc_type>::_S_do_it(_M_get_Tp_allocator(),
738 						    __x._M_get_Tp_allocator());
739       }
740 
741       /**
742        *  Erases all the elements.  Note that this function only erases the
743        *  elements, and that if the elements themselves are pointers, the
744        *  pointed-to memory is not touched in any way.  Managing the pointer is
745        *  the user's responsibilty.
746        */
747       void
748       clear()
749       { _M_erase_at_end(this->_M_impl._M_start); }
750 
751     protected:
752       /**
753        *  @if maint
754        *  Memory expansion handler.  Uses the member allocation function to
755        *  obtain @a n bytes of memory, and then copies [first,last) into it.
756        *  @endif
757        */
758       template<typename _ForwardIterator>
759         pointer
760         _M_allocate_and_copy(size_type __n,
761 			     _ForwardIterator __first, _ForwardIterator __last)
762         {
763 	  pointer __result = this->_M_allocate(__n);
764 	  try
765 	    {
766 	      std::__uninitialized_copy_a(__first, __last, __result,
767 					  _M_get_Tp_allocator());
768 	      return __result;
769 	    }
770 	  catch(...)
771 	    {
772 	      _M_deallocate(__result, __n);
773 	      __throw_exception_again;
774 	    }
775 	}
776 
777 
778       // Internal constructor functions follow.
779 
780       // Called by the range constructor to implement [23.1.1]/9
781       template<typename _Integer>
782         void
783         _M_initialize_dispatch(_Integer __n, _Integer __value, __true_type)
784         {
785 	  this->_M_impl._M_start = _M_allocate(__n);
786 	  this->_M_impl._M_end_of_storage = this->_M_impl._M_start + __n;
787 	  std::__uninitialized_fill_n_a(this->_M_impl._M_start, __n, __value,
788 					_M_get_Tp_allocator());
789 	  this->_M_impl._M_finish = this->_M_impl._M_end_of_storage;
790 	}
791 
792       // Called by the range constructor to implement [23.1.1]/9
793       template<typename _InputIterator>
794         void
795         _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
796 			       __false_type)
797         {
798 	  typedef typename std::iterator_traits<_InputIterator>::
799 	    iterator_category _IterCategory;
800 	  _M_range_initialize(__first, __last, _IterCategory());
801 	}
802 
803       // Called by the second initialize_dispatch above
804       template<typename _InputIterator>
805         void
806         _M_range_initialize(_InputIterator __first,
807 			    _InputIterator __last, std::input_iterator_tag)
808         {
809 	  for (; __first != __last; ++__first)
810 	    push_back(*__first);
811 	}
812 
813       // Called by the second initialize_dispatch above
814       template<typename _ForwardIterator>
815         void
816         _M_range_initialize(_ForwardIterator __first,
817 			    _ForwardIterator __last, std::forward_iterator_tag)
818         {
819 	  const size_type __n = std::distance(__first, __last);
820 	  this->_M_impl._M_start = this->_M_allocate(__n);
821 	  this->_M_impl._M_end_of_storage = this->_M_impl._M_start + __n;
822 	  this->_M_impl._M_finish =
823 	    std::__uninitialized_copy_a(__first, __last,
824 					this->_M_impl._M_start,
825 					_M_get_Tp_allocator());
826 	}
827 
828 
829       // Internal assign functions follow.  The *_aux functions do the actual
830       // assignment work for the range versions.
831 
832       // Called by the range assign to implement [23.1.1]/9
833       template<typename _Integer>
834         void
835         _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
836         {
837 	  _M_fill_assign(static_cast<size_type>(__n),
838 			 static_cast<value_type>(__val));
839 	}
840 
841       // Called by the range assign to implement [23.1.1]/9
842       template<typename _InputIterator>
843         void
844         _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
845 			   __false_type)
846         {
847 	  typedef typename std::iterator_traits<_InputIterator>::
848 	    iterator_category _IterCategory;
849 	  _M_assign_aux(__first, __last, _IterCategory());
850 	}
851 
852       // Called by the second assign_dispatch above
853       template<typename _InputIterator>
854         void
855         _M_assign_aux(_InputIterator __first, _InputIterator __last,
856 		      std::input_iterator_tag);
857 
858       // Called by the second assign_dispatch above
859       template<typename _ForwardIterator>
860         void
861         _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,
862 		      std::forward_iterator_tag);
863 
864       // Called by assign(n,t), and the range assign when it turns out
865       // to be the same thing.
866       void
867       _M_fill_assign(size_type __n, const value_type& __val);
868 
869 
870       // Internal insert functions follow.
871 
872       // Called by the range insert to implement [23.1.1]/9
873       template<typename _Integer>
874         void
875         _M_insert_dispatch(iterator __pos, _Integer __n, _Integer __val,
876 			   __true_type)
877         {
878 	  _M_fill_insert(__pos, static_cast<size_type>(__n),
879 			 static_cast<value_type>(__val));
880 	}
881 
882       // Called by the range insert to implement [23.1.1]/9
883       template<typename _InputIterator>
884         void
885         _M_insert_dispatch(iterator __pos, _InputIterator __first,
886 			   _InputIterator __last, __false_type)
887         {
888 	  typedef typename std::iterator_traits<_InputIterator>::
889 	    iterator_category _IterCategory;
890 	  _M_range_insert(__pos, __first, __last, _IterCategory());
891 	}
892 
893       // Called by the second insert_dispatch above
894       template<typename _InputIterator>
895         void
896         _M_range_insert(iterator __pos, _InputIterator __first,
897 			_InputIterator __last, std::input_iterator_tag);
898 
899       // Called by the second insert_dispatch above
900       template<typename _ForwardIterator>
901         void
902         _M_range_insert(iterator __pos, _ForwardIterator __first,
903 			_ForwardIterator __last, std::forward_iterator_tag);
904 
905       // Called by insert(p,n,x), and the range insert when it turns out to be
906       // the same thing.
907       void
908       _M_fill_insert(iterator __pos, size_type __n, const value_type& __x);
909 
910       // Called by insert(p,x)
911       void
912       _M_insert_aux(iterator __position, const value_type& __x);
913 
914       // Internal erase functions follow.
915 
916       // Called by erase(q1,q2), clear(), resize(), _M_fill_assign,
917       // _M_assign_aux.
918       void
919       _M_erase_at_end(pointer __pos)
920       {
921 	std::_Destroy(__pos, this->_M_impl._M_finish, _M_get_Tp_allocator());
922 	this->_M_impl._M_finish = __pos;
923       }
924     };
925 
926 
927   /**
928    *  @brief  Vector equality comparison.
929    *  @param  x  A %vector.
930    *  @param  y  A %vector of the same type as @a x.
931    *  @return  True iff the size and elements of the vectors are equal.
932    *
933    *  This is an equivalence relation.  It is linear in the size of the
934    *  vectors.  Vectors are considered equivalent if their sizes are equal,
935    *  and if corresponding elements compare equal.
936   */
937   template<typename _Tp, typename _Alloc>
938     inline bool
939     operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
940     { return (__x.size() == __y.size()
941 	      && std::equal(__x.begin(), __x.end(), __y.begin())); }
942 
943   /**
944    *  @brief  Vector ordering relation.
945    *  @param  x  A %vector.
946    *  @param  y  A %vector of the same type as @a x.
947    *  @return  True iff @a x is lexicographically less than @a y.
948    *
949    *  This is a total ordering relation.  It is linear in the size of the
950    *  vectors.  The elements must be comparable with @c <.
951    *
952    *  See std::lexicographical_compare() for how the determination is made.
953   */
954   template<typename _Tp, typename _Alloc>
955     inline bool
956     operator<(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
957     { return std::lexicographical_compare(__x.begin(), __x.end(),
958 					  __y.begin(), __y.end()); }
959 
960   /// Based on operator==
961   template<typename _Tp, typename _Alloc>
962     inline bool
963     operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
964     { return !(__x == __y); }
965 
966   /// Based on operator<
967   template<typename _Tp, typename _Alloc>
968     inline bool
969     operator>(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
970     { return __y < __x; }
971 
972   /// Based on operator<
973   template<typename _Tp, typename _Alloc>
974     inline bool
975     operator<=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
976     { return !(__y < __x); }
977 
978   /// Based on operator<
979   template<typename _Tp, typename _Alloc>
980     inline bool
981     operator>=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)
982     { return !(__x < __y); }
983 
984   /// See std::vector::swap().
985   template<typename _Tp, typename _Alloc>
986     inline void
987     swap(vector<_Tp, _Alloc>& __x, vector<_Tp, _Alloc>& __y)
988     { __x.swap(__y); }
989 
990 _GLIBCXX_END_NESTED_NAMESPACE
991 
992 #endif /* _VECTOR_H */
993