stl_deque.h

Go to the documentation of this file.
00001 // Deque implementation -*- C++ -*-
00002 
00003 // Copyright (C) 2001, 2002 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the
00007 // terms of the GNU General Public License as published by the
00008 // Free Software Foundation; either version 2, or (at your option)
00009 // any later version.
00010 
00011 // This library is distributed in the hope that it will be useful,
00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 // GNU General Public License for more details.
00015 
00016 // You should have received a copy of the GNU General Public License along
00017 // with this library; see the file COPYING.  If not, write to the Free
00018 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
00019 // USA.
00020 
00021 // As a special exception, you may use this file as part of a free software
00022 // library without restriction.  Specifically, if other files instantiate
00023 // templates or use macros or inline functions from this file, or you compile
00024 // this file and link it with other files to produce an executable, this
00025 // file does not by itself cause the resulting executable to be covered by
00026 // the GNU General Public License.  This exception does not however
00027 // invalidate any other reasons why the executable file might be covered by
00028 // the GNU General Public License.
00029 
00030 /*
00031  *
00032  * Copyright (c) 1994
00033  * Hewlett-Packard Company
00034  *
00035  * Permission to use, copy, modify, distribute and sell this software
00036  * and its documentation for any purpose is hereby granted without fee,
00037  * provided that the above copyright notice appear in all copies and
00038  * that both that copyright notice and this permission notice appear
00039  * in supporting documentation.  Hewlett-Packard Company makes no
00040  * representations about the suitability of this software for any
00041  * purpose.  It is provided "as is" without express or implied warranty.
00042  *
00043  *
00044  * Copyright (c) 1997
00045  * Silicon Graphics Computer Systems, Inc.
00046  *
00047  * Permission to use, copy, modify, distribute and sell this software
00048  * and its documentation for any purpose is hereby granted without fee,
00049  * provided that the above copyright notice appear in all copies and
00050  * that both that copyright notice and this permission notice appear
00051  * in supporting documentation.  Silicon Graphics makes no
00052  * representations about the suitability of this software for any
00053  * purpose.  It is provided "as is" without express or implied warranty.
00054  */
00055 
00056 /** @file stl_deque.h
00057  *  This is an internal header file, included by other library headers.
00058  *  You should not attempt to use it directly.
00059  */
00060 
00061 #ifndef __GLIBCPP_INTERNAL_DEQUE_H
00062 #define __GLIBCPP_INTERNAL_DEQUE_H
00063 
00064 #include <bits/concept_check.h>
00065 #include <bits/stl_iterator_base_types.h>
00066 #include <bits/stl_iterator_base_funcs.h>
00067 
00068 namespace std
00069 { 
00070   /**
00071    *  @if maint
00072    *  @brief This function controls the size of memory nodes.
00073    *  @param  size  The size of an element.
00074    *  @return   The number (not byte size) of elements per node.
00075    *
00076    *  This function started off as a compiler kludge from SGI, but seems to
00077    *  be a useful wrapper around a repeated constant expression.  The '512' is
00078    *  tuneable (and no other code needs to change), but no investigation has
00079    *  been done since inheriting the SGI code.
00080    *  @endif
00081   */
00082   inline size_t 
00083   __deque_buf_size(size_t __size) 
00084   { return __size < 512 ? size_t(512 / __size) : size_t(1); }
00085   
00086   
00087   /**
00088    *  @brief A deque::iterator.
00089    *
00090    *  Quite a bit of intelligence here.  Much of the functionality of deque is
00091    *  actually passed off to this class.  A deque holds two of these internally,
00092    *  marking its valid range.  Access to elements is done as offsets of either
00093    *  of those two, relying on operator overloading in this class.
00094    *
00095    *  @if maint
00096    *  All the functions are op overloads except for _M_set_node.
00097    *  @endif
00098   */
00099   template <typename _Tp, typename _Ref, typename _Ptr>
00100     struct _Deque_iterator
00101   {
00102     typedef _Deque_iterator<_Tp, _Tp&, _Tp*>             iterator;
00103     typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
00104     static size_t _S_buffer_size() { return __deque_buf_size(sizeof(_Tp)); }
00105   
00106     typedef random_access_iterator_tag iterator_category;
00107     typedef _Tp                        value_type;
00108     typedef _Ptr                       pointer;
00109     typedef _Ref                       reference;
00110     typedef size_t                     size_type;
00111     typedef ptrdiff_t                  difference_type;
00112     typedef _Tp**                      _Map_pointer;
00113     typedef _Deque_iterator            _Self;
00114   
00115     _Tp* _M_cur;
00116     _Tp* _M_first;
00117     _Tp* _M_last;
00118     _Map_pointer _M_node;
00119   
00120     _Deque_iterator(_Tp* __x, _Map_pointer __y) 
00121       : _M_cur(__x), _M_first(*__y),
00122         _M_last(*__y + _S_buffer_size()), _M_node(__y) {}
00123     _Deque_iterator() : _M_cur(0), _M_first(0), _M_last(0), _M_node(0) {}
00124     _Deque_iterator(const iterator& __x)
00125       : _M_cur(__x._M_cur), _M_first(__x._M_first), 
00126         _M_last(__x._M_last), _M_node(__x._M_node) {}
00127   
00128     reference operator*() const { return *_M_cur; }
00129     pointer operator->() const { return _M_cur; }
00130   
00131     _Self& operator++() {
00132       ++_M_cur;
00133       if (_M_cur == _M_last) {
00134         _M_set_node(_M_node + 1);
00135         _M_cur = _M_first;
00136       }
00137       return *this; 
00138     }
00139     _Self operator++(int)  {
00140       _Self __tmp = *this;
00141       ++*this;
00142       return __tmp;
00143     }
00144   
00145     _Self& operator--() {
00146       if (_M_cur == _M_first) {
00147         _M_set_node(_M_node - 1);
00148         _M_cur = _M_last;
00149       }
00150       --_M_cur;
00151       return *this;
00152     }
00153     _Self operator--(int) {
00154       _Self __tmp = *this;
00155       --*this;
00156       return __tmp;
00157     }
00158   
00159     _Self& operator+=(difference_type __n)
00160     {
00161       difference_type __offset = __n + (_M_cur - _M_first);
00162       if (__offset >= 0 && __offset < difference_type(_S_buffer_size()))
00163         _M_cur += __n;
00164       else {
00165         difference_type __node_offset =
00166           __offset > 0 ? __offset / difference_type(_S_buffer_size())
00167                      : -difference_type((-__offset - 1) / _S_buffer_size()) - 1;
00168         _M_set_node(_M_node + __node_offset);
00169         _M_cur = _M_first + 
00170           (__offset - __node_offset * difference_type(_S_buffer_size()));
00171       }
00172       return *this;
00173     }
00174   
00175     _Self operator+(difference_type __n) const
00176     {
00177       _Self __tmp = *this;
00178       return __tmp += __n;
00179     }
00180   
00181     _Self& operator-=(difference_type __n) { return *this += -__n; }
00182    
00183     _Self operator-(difference_type __n) const {
00184       _Self __tmp = *this;
00185       return __tmp -= __n;
00186     }
00187   
00188     reference operator[](difference_type __n) const { return *(*this + __n); }
00189   
00190     /** @if maint
00191      *  Prepares to traverse new_node.  Sets everything except _M_cur, which
00192      *  should therefore be set by the caller immediately afterwards, based on
00193      *  _M_first and _M_last.
00194      *  @endif
00195     */
00196     void
00197     _M_set_node(_Map_pointer __new_node)
00198     {
00199       _M_node = __new_node;
00200       _M_first = *__new_node;
00201       _M_last = _M_first + difference_type(_S_buffer_size());
00202     }
00203   };
00204   
00205   // Note: we also provide overloads whose operands are of the same type in
00206   // order to avoid ambiguous overload resolution when std::rel_ops operators
00207   // are in scope (for additional details, see libstdc++/3628)
00208   template <typename _Tp, typename _Ref, typename _Ptr>
00209   inline bool
00210   operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
00211        const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
00212   {
00213     return __x._M_cur == __y._M_cur;
00214   }
00215   
00216   template <typename _Tp, typename _RefL, typename _PtrL,
00217                           typename _RefR, typename _PtrR>
00218   inline bool
00219   operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
00220        const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
00221   {
00222     return __x._M_cur == __y._M_cur;
00223   }
00224   
00225   template <typename _Tp, typename _Ref, typename _Ptr>
00226   inline bool
00227   operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
00228        const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
00229   {
00230     return !(__x == __y);
00231   }
00232   
00233   template <typename _Tp, typename _RefL, typename _PtrL,
00234                           typename _RefR, typename _PtrR>
00235   inline bool
00236   operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
00237        const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
00238   {
00239     return !(__x == __y);
00240   }
00241   
00242   template <typename _Tp, typename _Ref, typename _Ptr>
00243   inline bool
00244   operator<(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
00245        const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
00246   {
00247     return (__x._M_node == __y._M_node) ? 
00248       (__x._M_cur < __y._M_cur) : (__x._M_node < __y._M_node);
00249   }
00250   
00251   template <typename _Tp, typename _RefL, typename _PtrL,
00252                           typename _RefR, typename _PtrR>
00253   inline bool
00254   operator<(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
00255        const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
00256   {
00257     return (__x._M_node == __y._M_node) ? 
00258       (__x._M_cur < __y._M_cur) : (__x._M_node < __y._M_node);
00259   }
00260   
00261   template <typename _Tp, typename _Ref, typename _Ptr>
00262   inline bool
00263   operator>(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
00264        const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
00265   {
00266     return __y < __x;
00267   }
00268   
00269   template <typename _Tp, typename _RefL, typename _PtrL,
00270                           typename _RefR, typename _PtrR>
00271   inline bool
00272   operator>(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
00273        const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
00274   {
00275     return __y < __x;
00276   }
00277   
00278   template <typename _Tp, typename _Ref, typename _Ptr>
00279   inline bool
00280   operator<=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
00281        const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
00282   {
00283     return !(__y < __x);
00284   }
00285   
00286   template <typename _Tp, typename _RefL, typename _PtrL,
00287                           typename _RefR, typename _PtrR>
00288   inline bool
00289   operator<=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
00290        const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
00291   {
00292     return !(__y < __x);
00293   }
00294   
00295   template <typename _Tp, typename _Ref, typename _Ptr>
00296   inline bool
00297   operator>=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
00298        const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
00299   {
00300     return !(__x < __y);
00301   }
00302   
00303   template <typename _Tp, typename _RefL, typename _PtrL,
00304                           typename _RefR, typename _PtrR>
00305   inline bool
00306   operator>=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
00307        const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
00308   {
00309     return !(__x < __y);
00310   }
00311   
00312   // _GLIBCPP_RESOLVE_LIB_DEFECTS
00313   // According to the resolution of DR179 not only the various comparison
00314   // operators but also operator- must accept mixed iterator/const_iterator
00315   // parameters.
00316   template <typename _Tp, typename _RefL, typename _PtrL,
00317                           typename _RefR, typename _PtrR>
00318   inline typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
00319   operator-(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
00320       const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
00321   {
00322     return _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
00323       (_Deque_iterator<_Tp, _RefL, _PtrL>::_S_buffer_size()) *
00324       (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first) +
00325       (__y._M_last - __y._M_cur);
00326   }
00327   
00328   template <typename _Tp, typename _Ref, typename _Ptr>
00329   inline _Deque_iterator<_Tp, _Ref, _Ptr>
00330   operator+(ptrdiff_t __n, const _Deque_iterator<_Tp, _Ref, _Ptr>& __x)
00331   {
00332     return __x + __n;
00333   }
00334   
00335   
00336   /// @if maint Primary default version.  @endif
00337   /**
00338    *  @if maint
00339    *  Deque base class.  It has two purposes.  First, its constructor
00340    *  and destructor allocate (but don't initialize) storage.  This makes
00341    *  %exception safety easier.  Second, the base class encapsulates all of
00342    *  the differences between SGI-style allocators and standard-conforming
00343    *  allocators.  (See stl_alloc.h for more on this topic.)  There are two
00344    *  versions:  this ordinary one, and the space-saving specialization for
00345    *  instanceless allocators.
00346    *  @endif
00347   */
00348   template <typename _Tp, typename _Alloc, bool __is_static>
00349     class _Deque_alloc_base
00350   {
00351   public:
00352     typedef typename _Alloc_traits<_Tp,_Alloc>::allocator_type allocator_type;
00353     allocator_type get_allocator() const { return _M_node_allocator; }
00354   
00355     _Deque_alloc_base(const allocator_type& __a)
00356       : _M_node_allocator(__a), _M_map_allocator(__a),
00357         _M_map(0), _M_map_size(0)
00358     {}
00359     
00360   protected:
00361     typedef typename _Alloc_traits<_Tp*, _Alloc>::allocator_type
00362             _Map_allocator_type;
00363   
00364     _Tp*
00365     _M_allocate_node()
00366     {
00367       return _M_node_allocator.allocate(__deque_buf_size(sizeof(_Tp)));
00368     }
00369   
00370     void
00371     _M_deallocate_node(_Tp* __p)
00372     {
00373       _M_node_allocator.deallocate(__p, __deque_buf_size(sizeof(_Tp)));
00374     }
00375   
00376     _Tp**
00377     _M_allocate_map(size_t __n) 
00378       { return _M_map_allocator.allocate(__n); }
00379   
00380     void
00381     _M_deallocate_map(_Tp** __p, size_t __n) 
00382       { _M_map_allocator.deallocate(__p, __n); }
00383   
00384     allocator_type       _M_node_allocator;
00385     _Map_allocator_type  _M_map_allocator;
00386     _Tp**                _M_map;
00387     size_t               _M_map_size;
00388   };
00389   
00390   /// @if maint Specialization for instanceless allocators.  @endif
00391   template <typename _Tp, typename _Alloc>
00392     class _Deque_alloc_base<_Tp, _Alloc, true>
00393   {
00394   public:
00395     typedef typename _Alloc_traits<_Tp,_Alloc>::allocator_type allocator_type;
00396     allocator_type get_allocator() const { return allocator_type(); }
00397   
00398     _Deque_alloc_base(const allocator_type&)
00399       : _M_map(0), _M_map_size(0)
00400     {}
00401     
00402   protected:
00403     typedef typename _Alloc_traits<_Tp,_Alloc>::_Alloc_type  _Node_alloc_type;
00404     typedef typename _Alloc_traits<_Tp*,_Alloc>::_Alloc_type _Map_alloc_type;
00405   
00406     _Tp*
00407     _M_allocate_node()
00408     {
00409       return _Node_alloc_type::allocate(__deque_buf_size(sizeof(_Tp)));
00410     }
00411   
00412     void
00413     _M_deallocate_node(_Tp* __p)
00414     {
00415       _Node_alloc_type::deallocate(__p, __deque_buf_size(sizeof(_Tp)));
00416     }
00417   
00418     _Tp**
00419     _M_allocate_map(size_t __n) 
00420       { return _Map_alloc_type::allocate(__n); }
00421   
00422     void
00423     _M_deallocate_map(_Tp** __p, size_t __n) 
00424       { _Map_alloc_type::deallocate(__p, __n); }
00425   
00426     _Tp**   _M_map;
00427     size_t  _M_map_size;
00428   };
00429   
00430   
00431   /**
00432    *  @if maint
00433    *  Deque base class.  Using _Alloc_traits in the instantiation of the parent
00434    *  class provides the compile-time dispatching mentioned in the parent's
00435    *  docs.  This class provides the unified face for %deque's allocation.
00436    *
00437    *  Nothing in this class ever constructs or destroys an actual Tp element.
00438    *  (Deque handles that itself.)  Only/All memory management is performed
00439    *  here.
00440    *  @endif
00441   */
00442   template <typename _Tp, typename _Alloc>
00443     class _Deque_base
00444     : public _Deque_alloc_base<_Tp,_Alloc,
00445                                 _Alloc_traits<_Tp, _Alloc>::_S_instanceless>
00446   {
00447   public:
00448     typedef _Deque_alloc_base<_Tp,_Alloc,
00449                                _Alloc_traits<_Tp, _Alloc>::_S_instanceless>
00450             _Base;
00451     typedef typename _Base::allocator_type             allocator_type;
00452     typedef _Deque_iterator<_Tp,_Tp&,_Tp*>             iterator;
00453     typedef _Deque_iterator<_Tp,const _Tp&,const _Tp*> const_iterator;
00454   
00455     _Deque_base(const allocator_type& __a, size_t __num_elements)
00456       : _Base(__a), _M_start(), _M_finish()
00457       { _M_initialize_map(__num_elements); }
00458     _Deque_base(const allocator_type& __a) 
00459       : _Base(__a), _M_start(), _M_finish() {}
00460     ~_Deque_base();    
00461   
00462   protected:
00463     void _M_initialize_map(size_t);
00464     void _M_create_nodes(_Tp** __nstart, _Tp** __nfinish);
00465     void _M_destroy_nodes(_Tp** __nstart, _Tp** __nfinish);
00466     enum { _S_initial_map_size = 8 };
00467   
00468     iterator _M_start;
00469     iterator _M_finish;
00470   };
00471   
00472   
00473   template <typename _Tp, typename _Alloc>
00474   _Deque_base<_Tp,_Alloc>::~_Deque_base()
00475   {
00476     if (_M_map)
00477     {
00478       _M_destroy_nodes(_M_start._M_node, _M_finish._M_node + 1);
00479       _M_deallocate_map(_M_map, _M_map_size);
00480     }
00481   }
00482   
00483   /**
00484    *  @if maint
00485    *  @brief Layout storage.
00486    *  @param  num_elements  The count of T's for which to allocate space
00487    *                        at first.
00488    *  @return   Nothing.
00489    *
00490    *  The initial underlying memory layout is a bit complicated...
00491    *  @endif
00492   */
00493   template <typename _Tp, typename _Alloc>
00494   void
00495   _Deque_base<_Tp,_Alloc>::_M_initialize_map(size_t __num_elements)
00496   {
00497     size_t __num_nodes = 
00498       __num_elements / __deque_buf_size(sizeof(_Tp)) + 1;
00499   
00500     _M_map_size = max((size_t) _S_initial_map_size, __num_nodes + 2);
00501     _M_map = _M_allocate_map(_M_map_size);
00502   
00503     // For "small" maps (needing less than _M_map_size nodes), allocation
00504     // starts in the middle elements and grows outwards.  So nstart may be the
00505     // beginning of _M_map, but for small maps it may be as far in as _M_map+3.
00506   
00507     _Tp** __nstart = _M_map + (_M_map_size - __num_nodes) / 2;
00508     _Tp** __nfinish = __nstart + __num_nodes;
00509       
00510     try 
00511       { _M_create_nodes(__nstart, __nfinish); }
00512     catch(...)
00513       {
00514         _M_deallocate_map(_M_map, _M_map_size);
00515         _M_map = 0;
00516         _M_map_size = 0;
00517         __throw_exception_again;
00518       }
00519     
00520     _M_start._M_set_node(__nstart);
00521     _M_finish._M_set_node(__nfinish - 1);
00522     _M_start._M_cur = _M_start._M_first;
00523     _M_finish._M_cur = _M_finish._M_first +
00524                        __num_elements % __deque_buf_size(sizeof(_Tp));
00525   }
00526   
00527   template <typename _Tp, typename _Alloc>
00528   void _Deque_base<_Tp,_Alloc>::_M_create_nodes(_Tp** __nstart, _Tp** __nfinish)
00529   {
00530     _Tp** __cur;
00531     try
00532       {
00533         for (__cur = __nstart; __cur < __nfinish; ++__cur)
00534           *__cur = _M_allocate_node();
00535       }
00536     catch(...)
00537       { 
00538         _M_destroy_nodes(__nstart, __cur);
00539         __throw_exception_again; 
00540       }
00541   }
00542   
00543   template <typename _Tp, typename _Alloc>
00544   void
00545   _Deque_base<_Tp,_Alloc>::_M_destroy_nodes(_Tp** __nstart, _Tp** __nfinish)
00546   {
00547     for (_Tp** __n = __nstart; __n < __nfinish; ++__n)
00548       _M_deallocate_node(*__n);
00549   }
00550   
00551   
00552   /**
00553    *  @brief  A standard container using fixed-size memory allocation and
00554    *  constant-time manipulation of elements at either end.
00555    *
00556    *  @ingroup Containers
00557    *  @ingroup Sequences
00558    *
00559    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
00560    *  <a href="tables.html#66">reversible container</a>, and a
00561    *  <a href="tables.html#67">sequence</a>, including the
00562    *  <a href="tables.html#68">optional sequence requirements</a>.
00563    *
00564    *  In previous HP/SGI versions of deque, there was an extra template
00565    *  parameter so users could control the node size.  This extension turned
00566    *  out to violate the C++ standard (it can be detected using template
00567    *  template parameters), and it was removed.
00568    *
00569    *  @if maint
00570    *  Here's how a deque<Tp> manages memory.  Each deque has 4 members:
00571    *  
00572    *  - Tp**        _M_map
00573    *  - size_t      _M_map_size
00574    *  - iterator    _M_start, _M_finish
00575    *  
00576    *  map_size is at least 8.  %map is an array of map_size pointers-to-"nodes".
00577    *  (The name %map has nothing to do with the std::map class, and "nodes"
00578    *  should not be confused with std::list's usage of "node".)
00579    *  
00580    *  A "node" has no specific type name as such, but it is referred to as
00581    *  "node" in this file.  It is a simple array-of-Tp.  If Tp is very large,
00582    *  there will be one Tp element per node (i.e., an "array" of one).
00583    *  For non-huge Tp's, node size is inversely related to Tp size:  the
00584    *  larger the Tp, the fewer Tp's will fit in a node.  The goal here is to
00585    *  keep the total size of a node relatively small and constant over different
00586    *  Tp's, to improve allocator efficiency.
00587    *  
00588    *  **** As I write this, the nodes are /not/ allocated using the high-speed
00589    *  memory pool.  There are 20 hours left in the year; perhaps I can fix
00590    *  this before 2002.
00591    *  
00592    *  Not every pointer in the %map array will point to a node.  If the initial
00593    *  number of elements in the deque is small, the /middle/ %map pointers will
00594    *  be valid, and the ones at the edges will be unused.  This same situation
00595    *  will arise as the %map grows:  available %map pointers, if any, will be on
00596    *  the ends.  As new nodes are created, only a subset of the %map's pointers
00597    *  need to be copied "outward".
00598    *
00599    *  Class invariants:
00600    * - For any nonsingular iterator i:
00601    *    - i.node points to a member of the %map array.  (Yes, you read that
00602    *      correctly:  i.node does not actually point to a node.)  The member of
00603    *      the %map array is what actually points to the node.
00604    *    - i.first == *(i.node)    (This points to the node (first Tp element).)
00605    *    - i.last  == i.first + node_size
00606    *    - i.cur is a pointer in the range [i.first, i.last).  NOTE:
00607    *      the implication of this is that i.cur is always a dereferenceable
00608    *      pointer, even if i is a past-the-end iterator.
00609    * - Start and Finish are always nonsingular iterators.  NOTE: this means that
00610    *   an empty deque must have one node, a deque with <N elements (where N is
00611    *   the node buffer size) must have one node, a deque with N through (2N-1)
00612    *   elements must have two nodes, etc.
00613    * - For every node other than start.node and finish.node, every element in
00614    *   the node is an initialized object.  If start.node == finish.node, then
00615    *   [start.cur, finish.cur) are initialized objects, and the elements outside
00616    *   that range are uninitialized storage.  Otherwise, [start.cur, start.last)
00617    *   and [finish.first, finish.cur) are initialized objects, and [start.first,
00618    *   start.cur) and [finish.cur, finish.last) are uninitialized storage.
00619    * - [%map, %map + map_size) is a valid, non-empty range.  
00620    * - [start.node, finish.node] is a valid range contained within 
00621    *   [%map, %map + map_size).  
00622    * - A pointer in the range [%map, %map + map_size) points to an allocated
00623    *   node if and only if the pointer is in the range
00624    *   [start.node, finish.node].
00625    *
00626    *  Here's the magic:  nothing in deque is "aware" of the discontiguous
00627    *  storage!
00628    *
00629    *  The memory setup and layout occurs in the parent, _Base, and the iterator
00630    *  class is entirely responsible for "leaping" from one node to the next.
00631    *  All the implementation routines for deque itself work only through the
00632    *  start and finish iterators.  This keeps the routines simple and sane,
00633    *  and we can use other standard algorithms as well.
00634    *  @endif
00635   */
00636   template <typename _Tp, typename _Alloc = allocator<_Tp> >
00637     class deque : protected _Deque_base<_Tp, _Alloc>
00638   {
00639     // concept requirements
00640     __glibcpp_class_requires(_Tp, _SGIAssignableConcept)
00641   
00642     typedef _Deque_base<_Tp, _Alloc>           _Base;
00643   
00644   public:
00645     typedef _Tp                                value_type;
00646     typedef value_type*                        pointer;
00647     typedef const value_type*                  const_pointer;
00648     typedef typename _Base::iterator           iterator;
00649     typedef typename _Base::const_iterator     const_iterator;
00650     typedef std::reverse_iterator<const_iterator>   const_reverse_iterator;
00651     typedef std::reverse_iterator<iterator>         reverse_iterator;
00652     typedef value_type&                        reference;
00653     typedef const value_type&                  const_reference;
00654     typedef size_t                             size_type;
00655     typedef ptrdiff_t                          difference_type;
00656     typedef typename _Base::allocator_type     allocator_type;
00657   
00658   protected:
00659     typedef pointer*                           _Map_pointer;
00660     static size_t _S_buffer_size() { return __deque_buf_size(sizeof(_Tp)); }
00661   
00662     // Functions controlling memory layout, and nothing else.
00663     using _Base::_M_initialize_map;
00664     using _Base::_M_create_nodes;
00665     using _Base::_M_destroy_nodes;
00666     using _Base::_M_allocate_node;
00667     using _Base::_M_deallocate_node;
00668     using _Base::_M_allocate_map;
00669     using _Base::_M_deallocate_map;
00670   
00671     /** @if maint
00672      *  A total of four data members accumulated down the heirarchy.  If the
00673      *  _Alloc type requires separate instances, then two of them will also be
00674      *  included in each deque.
00675      *  @endif
00676     */
00677     using _Base::_M_map;
00678     using _Base::_M_map_size;
00679     using _Base::_M_start;
00680     using _Base::_M_finish;
00681   
00682   public:
00683     // [23.2.1.1] construct/copy/destroy
00684     // (assign() and get_allocator() are also listed in this section)
00685     /**
00686      *  @brief  Default constructor creates no elements.
00687     */
00688     explicit
00689     deque(const allocator_type& __a = allocator_type()) 
00690       : _Base(__a, 0) {}
00691   
00692     /**
00693      *  @brief  Create a %deque with copies of an exemplar element.
00694      *  @param  n  The number of elements to initially create.
00695      *  @param  value  An element to copy.
00696      * 
00697      *  This constructor fills the %deque with @a n copies of @a value.
00698     */
00699     deque(size_type __n, const value_type& __value,
00700           const allocator_type& __a = allocator_type())
00701       : _Base(__a, __n)
00702       { _M_fill_initialize(__value); }
00703   
00704     /**
00705      *  @brief  Create a %deque with default elements.
00706      *  @param  n  The number of elements to initially create.
00707      * 
00708      *  This constructor fills the %deque with @a n copies of a
00709      *  default-constructed element.
00710     */
00711     explicit
00712     deque(size_type __n)
00713       : _Base(allocator_type(), __n)
00714       { _M_fill_initialize(value_type()); }
00715   
00716     /**
00717      *  @brief  %Deque copy constructor.
00718      *  @param  x  A %deque of identical element and allocator types.
00719      * 
00720      *  The newly-created %deque uses a copy of the allocation object used
00721      *  by @a x.
00722     */
00723     deque(const deque& __x)
00724       : _Base(__x.get_allocator(), __x.size()) 
00725       { uninitialized_copy(__x.begin(), __x.end(), _M_start); }
00726   
00727     /**
00728      *  @brief  Builds a %deque from a range.
00729      *  @param  first  An input iterator.
00730      *  @param  last  An input iterator.
00731      * 
00732      *  Create a %deque consisting of copies of the elements from [first,last).
00733      *
00734      *  If the iterators are forward, bidirectional, or random-access, then
00735      *  this will call the elements' copy constructor N times (where N is
00736      *  distance(first,last)) and do no memory reallocation.  But if only
00737      *  input iterators are used, then this will do at most 2N calls to the
00738      *  copy constructor, and logN memory reallocations.
00739     */
00740     template<typename _InputIterator>
00741       deque(_InputIterator __first, _InputIterator __last,
00742             const allocator_type& __a = allocator_type())
00743         : _Base(__a)
00744       {
00745         // Check whether it's an integral type.  If so, it's not an iterator.
00746         typedef typename _Is_integer<_InputIterator>::_Integral _Integral;
00747         _M_initialize_dispatch(__first, __last, _Integral());
00748       }
00749   
00750     /**
00751      *  The dtor only erases the elements, and note that if the elements
00752      *  themselves are pointers, the pointed-to memory is not touched in any
00753      *  way.  Managing the pointer is the user's responsibilty.
00754     */
00755     ~deque() { _Destroy(_M_start, _M_finish); }
00756   
00757     /**
00758      *  @brief  %Deque assignment operator.
00759      *  @param  x  A %deque of identical element and allocator types.
00760      * 
00761      *  All the elements of @a x are copied, but unlike the copy constructor,
00762      *  the allocator object is not copied.
00763     */
00764     deque&
00765     operator=(const deque& __x);
00766   
00767     /**
00768      *  @brief  Assigns a given value to a %deque.
00769      *  @param  n  Number of elements to be assigned.
00770      *  @param  val  Value to be assigned.
00771      *
00772      *  This function fills a %deque with @a n copies of the given value.
00773      *  Note that the assignment completely changes the %deque and that the
00774      *  resulting %deque's size is the same as the number of elements assigned.
00775      *  Old data may be lost.
00776     */
00777     void
00778     assign(size_type __n, const value_type& __val) { _M_fill_assign(__n, __val); }
00779   
00780     /**
00781      *  @brief  Assigns a range to a %deque.
00782      *  @param  first  An input iterator.
00783      *  @param  last   An input iterator.
00784      *
00785      *  This function fills a %deque with copies of the elements in the
00786      *  range [first,last).
00787      *
00788      *  Note that the assignment completely changes the %deque and that the
00789      *  resulting %deque's size is the same as the number of elements assigned.
00790      *  Old data may be lost.
00791     */
00792     template<typename _InputIterator>
00793       void
00794       assign(_InputIterator __first, _InputIterator __last)
00795       {
00796         typedef typename _Is_integer<_InputIterator>::_Integral _Integral;
00797         _M_assign_dispatch(__first, __last, _Integral());
00798       }
00799   
00800     /// Get a copy of the memory allocation object.
00801     allocator_type
00802     get_allocator() const { return _Base::get_allocator(); }
00803   
00804     // iterators
00805     /**
00806      *  Returns a read/write iterator that points to the first element in the
00807      *  %deque.  Iteration is done in ordinary element order.
00808     */
00809     iterator
00810     begin() { return _M_start; }
00811   
00812     /**
00813      *  Returns a read-only (constant) iterator that points to the first element
00814      *  in the %deque.  Iteration is done in ordinary element order.
00815     */
00816     const_iterator
00817     begin() const { return _M_start; }
00818   
00819     /**
00820      *  Returns a read/write iterator that points one past the last element in
00821      *  the %deque.  Iteration is done in ordinary element order.
00822     */
00823     iterator
00824     end() { return _M_finish; }
00825   
00826     /**
00827      *  Returns a read-only (constant) iterator that points one past the last
00828      *  element in the %deque.  Iteration is done in ordinary element order.
00829     */
00830     const_iterator
00831     end() const { return _M_finish; }
00832   
00833     /**
00834      *  Returns a read/write reverse iterator that points to the last element in
00835      *  the %deque.  Iteration is done in reverse element order.
00836     */
00837     reverse_iterator
00838     rbegin() { return reverse_iterator(_M_finish); }
00839   
00840     /**
00841      *  Returns a read-only (constant) reverse iterator that points to the last
00842      *  element in the %deque.  Iteration is done in reverse element order.
00843     */
00844     const_reverse_iterator
00845     rbegin() const { return const_reverse_iterator(_M_finish); }
00846   
00847     /**
00848      *  Returns a read/write reverse iterator that points to one before the
00849      *  first element in the %deque.  Iteration is done in reverse element
00850      *  order.
00851     */
00852     reverse_iterator
00853     rend() { return reverse_iterator(_M_start); }
00854   
00855     /**
00856      *  Returns a read-only (constant) reverse iterator that points to one
00857      *  before the first element in the %deque.  Iteration is done in reverse
00858      *  element order.
00859     */
00860     const_reverse_iterator
00861     rend() const { return const_reverse_iterator(_M_start); }
00862   
00863     // [23.2.1.2] capacity
00864     /**  Returns the number of elements in the %deque.  */
00865     size_type
00866     size() const { return _M_finish - _M_start; }
00867   
00868     /**  Returns the size() of the largest possible %deque.  */
00869     size_type
00870     max_size() const { return size_type(-1); }
00871   
00872     /**
00873      *  @brief  Resizes the %deque to the specified number of elements.
00874      *  @param  new_size  Number of elements the %deque should contain.
00875      *  @param  x  Data with which new elements should be populated.
00876      *
00877      *  This function will %resize the %deque to the specified number of
00878      *  elements.  If the number is smaller than the %deque's current size the
00879      *  %deque is truncated, otherwise the %deque is extended and new elements
00880      *  are populated with given data.
00881     */
00882     void
00883     resize(size_type __new_size, const value_type& __x)
00884     {
00885       const size_type __len = size();
00886       if (__new_size < __len) 
00887         erase(_M_start + __new_size, _M_finish);
00888       else
00889         insert(_M_finish, __new_size - __len, __x);
00890     }
00891   
00892     /**
00893      *  @brief  Resizes the %deque to the specified number of elements.
00894      *  @param  new_size  Number of elements the %deque should contain.
00895      *
00896      *  This function will resize the %deque to the specified number of
00897      *  elements.  If the number is smaller than the %deque's current size the
00898      *  %deque is truncated, otherwise the %deque is extended and new elements
00899      *  are default-constructed.
00900     */
00901     void
00902     resize(size_type new_size) { resize(new_size, value_type()); }
00903   
00904     /**
00905      *  Returns true if the %deque is empty.  (Thus begin() would equal end().)
00906     */
00907     bool empty() const { return _M_finish == _M_start; }
00908   
00909     // element access
00910     /**
00911      *  @brief  Subscript access to the data contained in the %deque.
00912      *  @param  n  The index of the element for which data should be accessed.
00913      *  @return  Read/write reference to data.
00914      *
00915      *  This operator allows for easy, array-style, data access.
00916      *  Note that data access with this operator is unchecked and out_of_range
00917      *  lookups are not defined. (For checked lookups see at().)
00918     */
00919     reference
00920     operator[](size_type __n) { return _M_start[difference_type(__n)]; }
00921   
00922     /**
00923      *  @brief  Subscript access to the data contained in the %deque.
00924      *  @param  n  The index of the element for which data should be accessed.
00925      *  @return  Read-only (constant) reference to data.
00926      *
00927      *  This operator allows for easy, array-style, data access.
00928      *  Note that data access with this operator is unchecked and out_of_range
00929      *  lookups are not defined. (For checked lookups see at().)
00930     */
00931     const_reference
00932     operator[](size_type __n) const { return _M_start[difference_type(__n)]; }
00933   
00934   protected:
00935     /// @if maint Safety check used only from at().  @endif
00936     void
00937     _M_range_check(size_type __n) const
00938     {
00939       if (__n >= this->size())
00940         __throw_out_of_range("deque [] access out of range");
00941     }
00942   
00943   public:
00944     /**
00945      *  @brief  Provides access to the data contained in the %deque.
00946      *  @param  n  The index of the element for which data should be accessed.
00947      *  @return  Read/write reference to data.
00948      *  @throw  std::out_of_range  If @a n is an invalid index.
00949      *
00950      *  This function provides for safer data access.  The parameter is first
00951      *  checked that it is in the range of the deque.  The function throws
00952      *  out_of_range if the check fails.
00953     */
00954     reference
00955     at(size_type __n) { _M_range_check(__n); return (*this)[__n]; }
00956   
00957     /**
00958      *  @brief  Provides access to the data contained in the %deque.
00959      *  @param  n  The index of the element for which data should be accessed.
00960      *  @return  Read-only (constant) reference to data.
00961      *  @throw  std::out_of_range  If @a n is an invalid index.
00962      *
00963      *  This function provides for safer data access.  The parameter is first
00964      *  checked that it is in the range of the deque.  The function throws
00965      *  out_of_range if the check fails.
00966     */
00967     const_reference
00968     at(size_type __n) const { _M_range_check(__n); return (*this)[__n]; }
00969   
00970     /**
00971      *  Returns a read/write reference to the data at the first element of the
00972      *  %deque.
00973     */
00974     reference
00975     front() { return *_M_start; }
00976   
00977     /**
00978      *  Returns a read-only (constant) reference to the data at the first
00979      *  element of the %deque.
00980     */
00981     const_reference
00982     front() const { return *_M_start; }
00983   
00984     /**
00985      *  Returns a read/write reference to the data at the last element of the
00986      *  %deque.
00987     */
00988     reference
00989     back()
00990     {
00991       iterator __tmp = _M_finish;
00992       --__tmp;
00993       return *__tmp;
00994     }
00995   
00996     /**
00997      *  Returns a read-only (constant) reference to the data at the last
00998      *  element of the %deque.
00999     */
01000     const_reference
01001     back() const
01002     {
01003       const_iterator __tmp = _M_finish;
01004       --__tmp;
01005       return *__tmp;
01006     }
01007   
01008     // [23.2.1.2] modifiers
01009     /**
01010      *  @brief  Add data to the front of the %deque.
01011      *  @param  x  Data to be added.
01012      *
01013      *  This is a typical stack operation.  The function creates an element at
01014      *  the front of the %deque and assigns the given data to it.  Due to the
01015      *  nature of a %deque this operation can be done in constant time.
01016     */
01017     void
01018     push_front(const value_type& __x) 
01019     {
01020       if (_M_start._M_cur != _M_start._M_first) {
01021         _Construct(_M_start._M_cur - 1, __x);
01022         --_M_start._M_cur;
01023       }
01024       else
01025         _M_push_front_aux(__x);
01026     }
01027   
01028   #ifdef _GLIBCPP_DEPRECATED
01029     /**
01030      *  @brief  Add data to the front of the %deque.
01031      *
01032      *  This is a typical stack operation.  The function creates a
01033      *  default-constructed element at the front of the %deque.  Due to the
01034      *  nature of a %deque this operation can be done in constant time.  You
01035      *  should consider using push_front(value_type()) instead.
01036      *
01037      *  @note This was deprecated in 3.2 and will be removed in 3.4.  You must
01038      *        define @c _GLIBCPP_DEPRECATED to make this visible in 3.2; see
01039      *        c++config.h.
01040     */
01041     void
01042     push_front()
01043     {
01044       if (_M_start._M_cur != _M_start._M_first) {
01045         _Construct(_M_start._M_cur - 1);
01046         --_M_start._M_cur;
01047       }
01048       else
01049         _M_push_front_aux();
01050     }
01051   #endif
01052   
01053     /**
01054      *  @brief  Add data to the end of the %deque.
01055      *  @param  x  Data to be added.
01056      *
01057      *  This is a typical stack operation.  The function creates an element at
01058      *  the end of the %deque and assigns the given data to it.  Due to the
01059      *  nature of a %deque this operation can be done in constant time.
01060     */
01061     void
01062     push_back(const value_type& __x)
01063     {
01064       if (_M_finish._M_cur != _M_finish._M_last - 1) {
01065         _Construct(_M_finish._M_cur, __x);
01066         ++_M_finish._M_cur;
01067       }
01068       else
01069         _M_push_back_aux(__x);
01070     }
01071   
01072   #ifdef _GLIBCPP_DEPRECATED
01073     /**
01074      *  @brief  Add data to the end of the %deque.
01075      *
01076      *  This is a typical stack operation.  The function creates a
01077      *  default-constructed element at the end of the %deque.  Due to the nature
01078      *  of a %deque this operation can be done in constant time.  You should
01079      *  consider using push_back(value_type()) instead.
01080      *
01081      *  @note This was deprecated in 3.2 and will be removed in 3.4.  You must
01082      *        define @c _GLIBCPP_DEPRECATED to make this visible in 3.2; see
01083      *        c++config.h.
01084     */
01085     void
01086     push_back()
01087     {
01088       if (_M_finish._M_cur != _M_finish._M_last - 1) {
01089         _Construct(_M_finish._M_cur);
01090         ++_M_finish._M_cur;
01091       }
01092       else
01093         _M_push_back_aux();
01094     }
01095   #endif
01096   
01097     /**
01098      *  @brief  Removes first element.
01099      *
01100      *  This is a typical stack operation.  It shrinks the %deque by one.
01101      *
01102      *  Note that no data is returned, and if the first element's data is
01103      *  needed, it should be retrieved before pop_front() is called.
01104     */
01105     void
01106     pop_front()
01107     {
01108       if (_M_start._M_cur != _M_start._M_last - 1) {
01109         _Destroy(_M_start._M_cur);
01110         ++_M_start._M_cur;
01111       }
01112       else 
01113         _M_pop_front_aux();
01114     }
01115   
01116     /**
01117      *  @brief  Removes last element.
01118      *
01119      *  This is a typical stack operation.  It shrinks the %deque by one.
01120      *
01121      *  Note that no data is returned, and if the last element's data is
01122      *  needed, it should be retrieved before pop_back() is called.
01123     */
01124     void
01125     pop_back()
01126     {
01127       if (_M_finish._M_cur != _M_finish._M_first) {
01128         --_M_finish._M_cur;
01129         _Destroy(_M_finish._M_cur);
01130       }
01131       else
01132         _M_pop_back_aux();
01133     }
01134   
01135     /**
01136      *  @brief  Inserts given value into %deque before specified iterator.
01137      *  @param  position  An iterator into the %deque.
01138      *  @param  x  Data to be inserted.
01139      *  @return  An iterator that points to the inserted data.
01140      *
01141      *  This function will insert a copy of the given value before the specified
01142      *  location.
01143     */
01144     iterator
01145     insert(iterator position, const value_type& __x);
01146   
01147   #ifdef _GLIBCPP_DEPRECATED
01148     /**
01149      *  @brief  Inserts an element into the %deque.
01150      *  @param  position  An iterator into the %deque.
01151      *  @return  An iterator that points to the inserted element.
01152      *
01153      *  This function will insert a default-constructed element before the
01154      *  specified location.  You should consider using
01155      *  insert(position,value_type()) instead.
01156      *
01157      *  @note This was deprecated in 3.2 and will be removed in 3.4.  You must
01158      *        define @c _GLIBCPP_DEPRECATED to make this visible in 3.2; see
01159      *        c++config.h.
01160     */
01161     iterator
01162     insert(iterator __position)
01163     { return insert(__position, value_type()); }
01164   #endif
01165   
01166     /**
01167      *  @brief  Inserts a number of copies of given data into the %deque.
01168      *  @param  position  An iterator into the %deque.
01169      *  @param  n  Number of elements to be inserted.
01170      *  @param  x  Data to be inserted.
01171      *
01172      *  This function will insert a specified number of copies of the given data
01173      *  before the location specified by @a position.
01174     */
01175     void
01176     insert(iterator __position, size_type __n, const value_type& __x)
01177     { _M_fill_insert(__position, __n, __x); }
01178   
01179     /**
01180      *  @brief  Inserts a range into the %deque.
01181      *  @param  pos  An iterator into the %deque.
01182      *  @param  first  An input iterator.
01183      *  @param  last   An input iterator.
01184      *
01185      *  This function will insert copies of the data in the range [first,last)
01186      *  into the %deque before the location specified by @a pos.  This is
01187      *  known as "range insert."
01188     */
01189     template<typename _InputIterator>
01190       void
01191       insert(iterator __pos, _InputIterator __first, _InputIterator __last)
01192       {
01193         // Check whether it's an integral type.  If so, it's not an iterator.
01194         typedef typename _Is_integer<_InputIterator>::_Integral _Integral;
01195         _M_insert_dispatch(__pos, __first, __last, _Integral());
01196       }
01197   
01198     /**
01199      *  @brief  Remove element at given position.
01200      *  @param  position  Iterator pointing to element to be erased.
01201      *  @return  An iterator pointing to the next element (or end()).
01202      *
01203      *  This function will erase the element at the given position and thus
01204      *  shorten the %deque by one.
01205      *
01206      *  The user is cautioned that
01207      *  this function only erases the element, and that if the element is itself
01208      *  a pointer, the pointed-to memory is not touched in any way.  Managing
01209      *  the pointer is the user's responsibilty.
01210     */
01211     iterator
01212     erase(iterator __position);
01213   
01214     /**
01215      *  @brief  Remove a range of elements.
01216      *  @param  first  Iterator pointing to the first element to be erased.
01217      *  @param  last  Iterator pointing to one past the last element to be
01218      *                erased.
01219      *  @return  An iterator pointing to the element pointed to by @a last
01220      *           prior to erasing (or end()).
01221      *
01222      *  This function will erase the elements in the range [first,last) and
01223      *  shorten the %deque accordingly.
01224      *
01225      *  The user is cautioned that
01226      *  this function only erases the elements, and that if the elements
01227      *  themselves are pointers, the pointed-to memory is not touched in any
01228      *  way.  Managing the pointer is the user's responsibilty.
01229     */
01230     iterator
01231     erase(iterator __first, iterator __last);
01232   
01233     /**
01234      *  @brief  Swaps data with another %deque.
01235      *  @param  x  A %deque of the same element and allocator types.
01236      *
01237      *  This exchanges the elements between two deques in constant time.
01238      *  (Four pointers, so it should be quite fast.)
01239      *  Note that the global std::swap() function is specialized such that
01240      *  std::swap(d1,d2) will feed to this function.
01241     */
01242     void
01243     swap(deque& __x)
01244     {
01245       std::swap(_M_start, __x._M_start);
01246       std::swap(_M_finish, __x._M_finish);
01247       std::swap(_M_map, __x._M_map);
01248       std::swap(_M_map_size, __x._M_map_size);
01249     }
01250   
01251     /**
01252      *  Erases all the elements.  Note that this function only erases the
01253      *  elements, and that if the elements themselves are pointers, the
01254      *  pointed-to memory is not touched in any way.  Managing the pointer is
01255      *  the user's responsibilty.
01256     */
01257     void clear(); 
01258   
01259   protected:
01260     // Internal constructor functions follow.
01261   
01262     // called by the range constructor to implement [23.1.1]/9
01263     template<typename _Integer>
01264       void
01265       _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type)
01266       {
01267         _M_initialize_map(__n);
01268         _M_fill_initialize(__x);
01269       }
01270   
01271     // called by the range constructor to implement [23.1.1]/9
01272     template<typename _InputIter>
01273       void
01274       _M_initialize_dispatch(_InputIter __first, _InputIter __last,
01275                              __false_type)
01276       {
01277         typedef typename iterator_traits<_InputIter>::iterator_category
01278                          _IterCategory;
01279         _M_range_initialize(__first, __last, _IterCategory());
01280       }
01281   
01282     // called by the second initialize_dispatch above
01283     //@{
01284     /**
01285      *  @if maint
01286      *  @brief Fills the deque with whatever is in [first,last).
01287      *  @param  first  An input iterator.
01288      *  @param  last  An input iterator.
01289      *  @return   Nothing.
01290      *
01291      *  If the iterators are actually forward iterators (or better), then the
01292      *  memory layout can be done all at once.  Else we move forward using
01293      *  push_back on each value from the iterator.
01294      *  @endif
01295     */
01296     template <typename _InputIterator>
01297       void
01298       _M_range_initialize(_InputIterator __first, _InputIterator __last,
01299                           input_iterator_tag);
01300   
01301     // called by the second initialize_dispatch above
01302     template <typename _ForwardIterator>
01303       void
01304       _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last,
01305                           forward_iterator_tag);
01306     //@}
01307   
01308     /**
01309      *  @if maint
01310      *  @brief Fills the %deque with copies of value.
01311      *  @param  value  Initial value.
01312      *  @return   Nothing.
01313      *  @pre _M_start and _M_finish have already been initialized, but none of
01314      *       the %deque's elements have yet been constructed.
01315      *
01316      *  This function is called only when the user provides an explicit size
01317      *  (with or without an explicit exemplar value).
01318      *  @endif
01319     */
01320     void
01321     _M_fill_initialize(const value_type& __value);
01322   
01323   
01324     // Internal assign functions follow.  The *_aux functions do the actual
01325     // assignment work for the range versions.
01326   
01327     // called by the range assign to implement [23.1.1]/9
01328     template<typename _Integer>
01329       void
01330       _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
01331       {
01332         _M_fill_assign(static_cast<size_type>(__n),
01333                        static_cast<value_type>(__val));
01334       }
01335   
01336     // called by the range assign to implement [23.1.1]/9
01337     template<typename _InputIter>
01338       void
01339       _M_assign_dispatch(_InputIter __first, _InputIter __last, __false_type)
01340       {
01341         typedef typename iterator_traits<_InputIter>::iterator_category
01342                          _IterCategory;
01343         _M_assign_aux(__first, __last, _IterCategory());
01344       }
01345   
01346     // called by the second assign_dispatch above
01347     template <typename _InputIterator>
01348       void
01349       _M_assign_aux(_InputIterator __first, _InputIterator __last,
01350                     input_iterator_tag);
01351   
01352     // called by the second assign_dispatch above
01353     template <typename _ForwardIterator>
01354       void
01355       _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,
01356                     forward_iterator_tag)
01357       {
01358         size_type __len = distance(__first, __last);
01359         if (__len > size()) {
01360           _ForwardIterator __mid = __first;
01361           advance(__mid, size());
01362           copy(__first, __mid, begin());
01363           insert(end(), __mid, __last);
01364         }
01365         else
01366           erase(copy(__first, __last, begin()), end());
01367       }
01368   
01369     // Called by assign(n,t), and the range assign when it turns out to be the
01370     // same thing.
01371     void
01372     _M_fill_assign(size_type __n, const value_type& __val)
01373     {
01374       if (__n > size())
01375       {
01376         fill(begin(), end(), __val);
01377         insert(end(), __n - size(), __val);
01378       }
01379       else
01380       {
01381         erase(begin() + __n, end());
01382         fill(begin(), end(), __val);
01383       }
01384     }
01385   
01386   
01387     //@{
01388     /**
01389      *  @if maint
01390      *  @brief Helper functions for push_* and pop_*.
01391      *  @endif
01392     */
01393     void _M_push_back_aux(const value_type&);
01394     void _M_push_front_aux(const value_type&);
01395   #ifdef _GLIBCPP_DEPRECATED
01396     void _M_push_back_aux();
01397     void _M_push_front_aux();
01398   #endif
01399     void _M_pop_back_aux();
01400     void _M_pop_front_aux();
01401     //@}
01402   
01403   
01404     // Internal insert functions follow.  The *_aux functions do the actual
01405     // insertion work when all shortcuts fail.
01406   
01407     // called by the range insert to implement [23.1.1]/9
01408     template<typename _Integer>
01409       void
01410       _M_insert_dispatch(iterator __pos,
01411                          _Integer __n, _Integer __x, __true_type)
01412       {
01413         _M_fill_insert(__pos, static_cast<size_type>(__n),
01414                        static_cast<value_type>(__x));
01415       }
01416   
01417     // called by the range insert to implement [23.1.1]/9
01418     template<typename _InputIterator>
01419       void
01420       _M_insert_dispatch(iterator __pos,
01421                          _InputIterator __first, _InputIterator __last,
01422                          __false_type)
01423       {
01424         typedef typename iterator_traits<_InputIterator>::iterator_category
01425                          _IterCategory;
01426         _M_range_insert_aux(__pos, __first, __last, _IterCategory());
01427       }
01428   
01429     // called by the second insert_dispatch above
01430     template <typename _InputIterator>
01431       void
01432       _M_range_insert_aux(iterator __pos, _InputIterator __first,
01433                           _InputIterator __last, input_iterator_tag);
01434   
01435     // called by the second insert_dispatch above
01436     template <typename _ForwardIterator>
01437       void
01438       _M_range_insert_aux(iterator __pos, _ForwardIterator __first,
01439                           _ForwardIterator __last, forward_iterator_tag);
01440   
01441     // Called by insert(p,n,x), and the range insert when it turns out to be
01442     // the same thing.  Can use fill functions in optimal situations, otherwise
01443     // passes off to insert_aux(p,n,x).
01444     void
01445     _M_fill_insert(iterator __pos, size_type __n, const value_type& __x); 
01446   
01447     // called by insert(p,x)
01448     iterator
01449     _M_insert_aux(iterator __pos, const value_type& __x);
01450   
01451     // called by insert(p,n,x) via fill_insert
01452     void
01453     _M_insert_aux(iterator __pos, size_type __n, const value_type& __x);
01454   
01455     // called by range_insert_aux for forward iterators
01456     template <typename _ForwardIterator>
01457       void
01458       _M_insert_aux(iterator __pos, 
01459                     _ForwardIterator __first, _ForwardIterator __last,
01460                     size_type __n);
01461   
01462   #ifdef _GLIBCPP_DEPRECATED
01463     // unused, see comment in implementation
01464     iterator _M_insert_aux(iterator __pos);
01465   #endif
01466   
01467     //@{
01468     /**
01469      *  @if maint
01470      *  @brief Memory-handling helpers for the previous internal insert
01471      *         functions.
01472      *  @endif
01473     */
01474     iterator
01475     _M_reserve_elements_at_front(size_type __n)
01476     {
01477       size_type __vacancies = _M_start._M_cur - _M_start._M_first;
01478       if (__n > __vacancies) 
01479         _M_new_elements_at_front(__n - __vacancies);
01480       return _M_start - difference_type(__n);
01481     }
01482   
01483     iterator
01484     _M_reserve_elements_at_back(size_type __n)
01485     {
01486       size_type __vacancies = (_M_finish._M_last - _M_finish._M_cur) - 1;
01487       if (__n > __vacancies)
01488         _M_new_elements_at_back(__n - __vacancies);
01489       return _M_finish + difference_type(__n);
01490     }
01491   
01492     void
01493     _M_new_elements_at_front(size_type __new_elements);
01494   
01495     void
01496     _M_new_elements_at_back(size_type __new_elements);
01497     //@}
01498   
01499   
01500     //@{
01501     /**
01502      *  @if maint
01503      *  @brief Memory-handling helpers for the major %map.
01504      *
01505      *  Makes sure the _M_map has space for new nodes.  Does not actually add
01506      *  the nodes.  Can invalidate _M_map pointers.  (And consequently, %deque
01507      *  iterators.)
01508      *  @endif
01509     */
01510     void
01511     _M_reserve_map_at_back (size_type __nodes_to_add = 1)
01512     {
01513       if (__nodes_to_add + 1 > _M_map_size - (_M_finish._M_node - _M_map))
01514         _M_reallocate_map(__nodes_to_add, false);
01515     }
01516   
01517     void
01518     _M_reserve_map_at_front (size_type __nodes_to_add = 1)
01519     {
01520       if (__nodes_to_add > size_type(_M_start._M_node - _M_map))
01521         _M_reallocate_map(__nodes_to_add, true);
01522     }
01523   
01524     void
01525     _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front);
01526     //@}
01527   };
01528   
01529   
01530   /**
01531    *  @brief  Deque equality comparison.
01532    *  @param  x  A %deque.
01533    *  @param  y  A %deque of the same type as @a x.
01534    *  @return  True iff the size and elements of the deques are equal.
01535    *
01536    *  This is an equivalence relation.  It is linear in the size of the
01537    *  deques.  Deques are considered equivalent if their sizes are equal,
01538    *  and if corresponding elements compare equal.
01539   */
01540   template <typename _Tp, typename _Alloc>
01541   inline bool operator==(const deque<_Tp, _Alloc>& __x,
01542                          const deque<_Tp, _Alloc>& __y)
01543   {
01544     return __x.size() == __y.size() &&
01545            equal(__x.begin(), __x.end(), __y.begin());
01546   }
01547   
01548   /**
01549    *  @brief  Deque ordering relation.
01550    *  @param  x  A %deque.
01551    *  @param  y  A %deque of the same type as @a x.
01552    *  @return  True iff @a x is lexographically less than @a y.
01553    *
01554    *  This is a total ordering relation.  It is linear in the size of the
01555    *  deques.  The elements must be comparable with @c <.
01556    *
01557    *  See std::lexographical_compare() for how the determination is made.
01558   */
01559   template <typename _Tp, typename _Alloc>
01560   inline bool operator<(const deque<_Tp, _Alloc>& __x,
01561                         const deque<_Tp, _Alloc>& __y)
01562   {
01563     return lexicographical_compare(__x.begin(), __x.end(), 
01564                                    __y.begin(), __y.end());
01565   }
01566   
01567   /// Based on operator==
01568   template <typename _Tp, typename _Alloc>
01569   inline bool operator!=(const deque<_Tp, _Alloc>& __x,
01570                          const deque<_Tp, _Alloc>& __y) {
01571     return !(__x == __y);
01572   }
01573   
01574   /// Based on operator<
01575   template <typename _Tp, typename _Alloc>
01576   inline bool operator>(const deque<_Tp, _Alloc>& __x,
01577                         const deque<_Tp, _Alloc>& __y) {
01578     return __y < __x;
01579   }
01580   
01581   /// Based on operator<
01582   template <typename _Tp, typename _Alloc>
01583   inline bool operator<=(const deque<_Tp, _Alloc>& __x,
01584                          const deque<_Tp, _Alloc>& __y) {
01585     return !(__y < __x);
01586   }
01587   
01588   /// Based on operator<
01589   template <typename _Tp, typename _Alloc>
01590   inline bool operator>=(const deque<_Tp, _Alloc>& __x,
01591                          const deque<_Tp, _Alloc>& __y) {
01592     return !(__x < __y);
01593   }
01594   
01595   /// See std::deque::swap().
01596   template <typename _Tp, typename _Alloc>
01597   inline void swap(deque<_Tp,_Alloc>& __x, deque<_Tp,_Alloc>& __y)
01598   {
01599     __x.swap(__y);
01600   }
01601 } // namespace std 
01602   
01603 #endif /* __GLIBCPP_INTERNAL_DEQUE_H */

Generated on Thu Feb 10 23:22:58 2005 for libstdc++-v3 Source by  doxygen 1.4.0