# stl_deque.h

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    00001 // Deque implementation -*- C++ -*-
    00002
    00003 // Copyright (C) 2001, 2002, 2003, 2004, 2005 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 _DEQUE_H
    00062 #define _DEQUE_H 1
    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 _GLIBCXX_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
    00091    *  deque is actually passed off to this class.  A deque holds two
    00092    *  of these internally, marking its valid range.  Access to
    00093    *  elements is done as offsets of either of those two, relying on
    00094    *  operator overloading in this class.
    00095    *
    00096    *  @if maint
    00097    *  All the functions are op overloads except for _M_set_node.
    00098    *  @endif
    00099   */
    00100   template<typename _Tp, typename _Ref, typename _Ptr>
    00101     struct _Deque_iterator
    00102     {
    00103       typedef _Deque_iterator<_Tp, _Tp&, _Tp*>             iterator;
    00104       typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
    00105
    00106       static size_t _S_buffer_size()
    00107       { return __deque_buf_size(sizeof(_Tp)); }
    00108
    00109       typedef random_access_iterator_tag iterator_category;
    00110       typedef _Tp                        value_type;
    00111       typedef _Ptr                       pointer;
    00112       typedef _Ref                       reference;
    00113       typedef size_t                     size_type;
    00114       typedef ptrdiff_t                  difference_type;
    00115       typedef _Tp**                      _Map_pointer;
    00116       typedef _Deque_iterator            _Self;
    00117
    00118       _Tp* _M_cur;
    00119       _Tp* _M_first;
    00120       _Tp* _M_last;
    00121       _Map_pointer _M_node;
    00122
    00123       _Deque_iterator(_Tp* __x, _Map_pointer __y)
    00124       : _M_cur(__x), _M_first(*__y),
    00125         _M_last(*__y + _S_buffer_size()), _M_node(__y) {}
    00126
    00127       _Deque_iterator() : _M_cur(0), _M_first(0), _M_last(0), _M_node(0) {}
    00128
    00129       _Deque_iterator(const iterator& __x)
    00130       : _M_cur(__x._M_cur), _M_first(__x._M_first),
    00131         _M_last(__x._M_last), _M_node(__x._M_node) {}
    00132
    00133       reference
    00134       operator*() const
    00135       { return *_M_cur; }
    00136
    00137       pointer
    00138       operator->() const
    00139       { return _M_cur; }
    00140
    00141       _Self&
    00142       operator++()
    00143       {
    00144     ++_M_cur;
    00145     if (_M_cur == _M_last)
    00146       {
    00147         _M_set_node(_M_node + 1);
    00148         _M_cur = _M_first;
    00149       }
    00150     return *this;
    00151       }
    00152
    00153       _Self
    00154       operator++(int)
    00155       {
    00156     _Self __tmp = *this;
    00157     ++*this;
    00158     return __tmp;
    00159       }
    00160
    00161       _Self&
    00162       operator--()
    00163       {
    00164     if (_M_cur == _M_first)
    00165       {
    00166         _M_set_node(_M_node - 1);
    00167         _M_cur = _M_last;
    00168       }
    00169     --_M_cur;
    00170     return *this;
    00171       }
    00172
    00173       _Self
    00174       operator--(int)
    00175       {
    00176     _Self __tmp = *this;
    00177     --*this;
    00178     return __tmp;
    00179       }
    00180
    00181       _Self&
    00182       operator+=(difference_type __n)
    00183       {
    00184     const difference_type __offset = __n + (_M_cur - _M_first);
    00185     if (__offset >= 0 && __offset < difference_type(_S_buffer_size()))
    00186       _M_cur += __n;
    00187     else
    00188       {
    00189         const difference_type __node_offset =
    00190           __offset > 0 ? __offset / difference_type(_S_buffer_size())
    00191                        : -difference_type((-__offset - 1)
    00192                           / _S_buffer_size()) - 1;
    00193         _M_set_node(_M_node + __node_offset);
    00194         _M_cur = _M_first + (__offset - __node_offset
    00195                  * difference_type(_S_buffer_size()));
    00196       }
    00197     return *this;
    00198       }
    00199
    00200       _Self
    00201       operator+(difference_type __n) const
    00202       {
    00203     _Self __tmp = *this;
    00204     return __tmp += __n;
    00205       }
    00206
    00207       _Self&
    00208       operator-=(difference_type __n)
    00209       { return *this += -__n; }
    00210
    00211       _Self
    00212       operator-(difference_type __n) const
    00213       {
    00214     _Self __tmp = *this;
    00215     return __tmp -= __n;
    00216       }
    00217
    00218       reference
    00219       operator[](difference_type __n) const
    00220       { return *(*this + __n); }
    00221
    00222       /** @if maint
    00223        *  Prepares to traverse new_node.  Sets everything except
    00224        *  _M_cur, which should therefore be set by the caller
    00225        *  immediately afterwards, based on _M_first and _M_last.
    00226        *  @endif
    00227        */
    00228       void
    00229       _M_set_node(_Map_pointer __new_node)
    00230       {
    00231     _M_node = __new_node;
    00232     _M_first = *__new_node;
    00233     _M_last = _M_first + difference_type(_S_buffer_size());
    00234       }
    00235     };
    00236
    00237   // Note: we also provide overloads whose operands are of the same type in
    00238   // order to avoid ambiguous overload resolution when std::rel_ops operators
    00239   // are in scope (for additional details, see libstdc++/3628)
    00240   template<typename _Tp, typename _Ref, typename _Ptr>
    00241     inline bool
    00242     operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
    00243            const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
    00244     { return __x._M_cur == __y._M_cur; }
    00245
    00246   template<typename _Tp, typename _RefL, typename _PtrL,
    00247        typename _RefR, typename _PtrR>
    00248     inline bool
    00249     operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
    00250            const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
    00251     { return __x._M_cur == __y._M_cur; }
    00252
    00253   template<typename _Tp, typename _Ref, typename _Ptr>
    00254     inline bool
    00255     operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
    00256            const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
    00257     { return !(__x == __y); }
    00258
    00259   template<typename _Tp, typename _RefL, typename _PtrL,
    00260        typename _RefR, typename _PtrR>
    00261     inline bool
    00262     operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
    00263            const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
    00264     { return !(__x == __y); }
    00265
    00266   template<typename _Tp, typename _Ref, typename _Ptr>
    00267     inline bool
    00268     operator<(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
    00269           const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
    00270     { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur)
    00271                                           : (__x._M_node < __y._M_node); }
    00272
    00273   template<typename _Tp, typename _RefL, typename _PtrL,
    00274        typename _RefR, typename _PtrR>
    00275     inline bool
    00276     operator<(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
    00277           const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
    00278     { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur)
    00279                                       : (__x._M_node < __y._M_node); }
    00280
    00281   template<typename _Tp, typename _Ref, typename _Ptr>
    00282     inline bool
    00283     operator>(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
    00284           const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
    00285     { return __y < __x; }
    00286
    00287   template<typename _Tp, typename _RefL, typename _PtrL,
    00288        typename _RefR, typename _PtrR>
    00289     inline bool
    00290     operator>(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
    00291           const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
    00292     { return __y < __x; }
    00293
    00294   template<typename _Tp, typename _Ref, typename _Ptr>
    00295     inline bool
    00296     operator<=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
    00297            const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
    00298     { return !(__y < __x); }
    00299
    00300   template<typename _Tp, typename _RefL, typename _PtrL,
    00301        typename _RefR, typename _PtrR>
    00302     inline bool
    00303     operator<=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
    00304            const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
    00305     { return !(__y < __x); }
    00306
    00307   template<typename _Tp, typename _Ref, typename _Ptr>
    00308     inline bool
    00309     operator>=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
    00310            const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
    00311     { return !(__x < __y); }
    00312
    00313   template<typename _Tp, typename _RefL, typename _PtrL,
    00314        typename _RefR, typename _PtrR>
    00315     inline bool
    00316     operator>=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
    00317            const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
    00318     { return !(__x < __y); }
    00319
    00320   // _GLIBCXX_RESOLVE_LIB_DEFECTS
    00321   // According to the resolution of DR179 not only the various comparison
    00322   // operators but also operator- must accept mixed iterator/const_iterator
    00323   // parameters.
    00324   template<typename _Tp, typename _RefL, typename _PtrL,
    00325        typename _RefR, typename _PtrR>
    00326     inline typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
    00327     operator-(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
    00328           const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
    00329     {
    00330       return typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
    00331     (_Deque_iterator<_Tp, _RefL, _PtrL>::_S_buffer_size())
    00332     * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first)
    00333     + (__y._M_last - __y._M_cur);
    00334     }
    00335
    00336   template<typename _Tp, typename _Ref, typename _Ptr>
    00337     inline _Deque_iterator<_Tp, _Ref, _Ptr>
    00338     operator+(ptrdiff_t __n, const _Deque_iterator<_Tp, _Ref, _Ptr>& __x)
    00339     { return __x + __n; }
    00340
    00341   /**
    00342    *  @if maint
    00343    *  Deque base class.  This class provides the unified face for %deque's
    00344    *  allocation.  This class's constructor and destructor allocate and
    00345    *  deallocate (but do not initialize) storage.  This makes %exception
    00346    *  safety easier.
    00347    *
    00348    *  Nothing in this class ever constructs or destroys an actual Tp element.
    00349    *  (Deque handles that itself.)  Only/All memory management is performed
    00350    *  here.
    00351    *  @endif
    00352   */
    00353   template<typename _Tp, typename _Alloc>
    00354     class _Deque_base
    00355     {
    00356     public:
    00357       typedef _Alloc                  allocator_type;
    00358
    00359       allocator_type
    00360       get_allocator() const
    00361       { return *static_cast<const _Alloc*>(&this->_M_impl); }
    00362
    00363       typedef _Deque_iterator<_Tp, _Tp&, _Tp*>             iterator;
    00364       typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
    00365
    00366       _Deque_base(const allocator_type& __a, size_t __num_elements)
    00367       : _M_impl(__a)
    00368       { _M_initialize_map(__num_elements); }
    00369
    00370       _Deque_base(const allocator_type& __a)
    00371       : _M_impl(__a)
    00372       { }
    00373
    00374       ~_Deque_base();
    00375
    00376     protected:
    00377       //This struct encapsulates the implementation of the std::deque
    00378       //standard container and at the same time makes use of the EBO
    00379       //for empty allocators.
    00380       struct _Deque_impl
    00381       : public _Alloc
    00382       {
    00383     _Tp** _M_map;
    00384     size_t _M_map_size;
    00385     iterator _M_start;
    00386     iterator _M_finish;
    00387
    00388     _Deque_impl(const _Alloc& __a)
    00389     : _Alloc(__a), _M_map(0), _M_map_size(0), _M_start(), _M_finish()
    00390     { }
    00391       };
    00392
    00393       typedef typename _Alloc::template rebind<_Tp*>::other _Map_alloc_type;
    00394       _Map_alloc_type _M_get_map_allocator() const
    00395       { return _Map_alloc_type(this->get_allocator()); }
    00396
    00397       _Tp*
    00398       _M_allocate_node()
    00399       { return _M_impl._Alloc::allocate(__deque_buf_size(sizeof(_Tp))); }
    00400
    00401       void
    00402       _M_deallocate_node(_Tp* __p)
    00403       { _M_impl._Alloc::deallocate(__p, __deque_buf_size(sizeof(_Tp))); }
    00404
    00405       _Tp**
    00406       _M_allocate_map(size_t __n)
    00407       { return _M_get_map_allocator().allocate(__n); }
    00408
    00409       void
    00410       _M_deallocate_map(_Tp** __p, size_t __n)
    00411       { _M_get_map_allocator().deallocate(__p, __n); }
    00412
    00413     protected:
    00414       void _M_initialize_map(size_t);
    00415       void _M_create_nodes(_Tp** __nstart, _Tp** __nfinish);
    00416       void _M_destroy_nodes(_Tp** __nstart, _Tp** __nfinish);
    00417       enum { _S_initial_map_size = 8 };
    00418
    00419       _Deque_impl _M_impl;
    00420     };
    00421
    00422   template<typename _Tp, typename _Alloc>
    00423     _Deque_base<_Tp, _Alloc>::
    00424     ~_Deque_base()
    00425     {
    00426       if (this->_M_impl._M_map)
    00427     {
    00428       _M_destroy_nodes(this->_M_impl._M_start._M_node,
    00429                this->_M_impl._M_finish._M_node + 1);
    00430       _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
    00431     }
    00432     }
    00433
    00434   /**
    00435    *  @if maint
    00436    *  @brief Layout storage.
    00437    *  @param  num_elements  The count of T's for which to allocate space
    00438    *                        at first.
    00439    *  @return   Nothing.
    00440    *
    00441    *  The initial underlying memory layout is a bit complicated...
    00442    *  @endif
    00443   */
    00444   template<typename _Tp, typename _Alloc>
    00445     void
    00446     _Deque_base<_Tp, _Alloc>::
    00447     _M_initialize_map(size_t __num_elements)
    00448     {
    00449       const size_t __num_nodes = (__num_elements/ __deque_buf_size(sizeof(_Tp))
    00450                   + 1);
    00451
    00452       this->_M_impl._M_map_size = std::max((size_t) _S_initial_map_size,
    00453                        size_t(__num_nodes + 2));
    00454       this->_M_impl._M_map = _M_allocate_map(this->_M_impl._M_map_size);
    00455
    00456       // For "small" maps (needing less than _M_map_size nodes), allocation
    00457       // starts in the middle elements and grows outwards.  So nstart may be
    00458       // the beginning of _M_map, but for small maps it may be as far in as
    00459       // _M_map+3.
    00460
    00461       _Tp** __nstart = (this->_M_impl._M_map
    00462             + (this->_M_impl._M_map_size - __num_nodes) / 2);
    00463       _Tp** __nfinish = __nstart + __num_nodes;
    00464
    00465       try
    00466     { _M_create_nodes(__nstart, __nfinish); }
    00467       catch(...)
    00468     {
    00469       _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
    00470       this->_M_impl._M_map = 0;
    00471       this->_M_impl._M_map_size = 0;
    00472       __throw_exception_again;
    00473     }
    00474
    00475       this->_M_impl._M_start._M_set_node(__nstart);
    00476       this->_M_impl._M_finish._M_set_node(__nfinish - 1);
    00477       this->_M_impl._M_start._M_cur = _M_impl._M_start._M_first;
    00478       this->_M_impl._M_finish._M_cur = (this->_M_impl._M_finish._M_first
    00479                     + __num_elements
    00480                     % __deque_buf_size(sizeof(_Tp)));
    00481     }
    00482
    00483   template<typename _Tp, typename _Alloc>
    00484     void
    00485     _Deque_base<_Tp, _Alloc>::
    00486     _M_create_nodes(_Tp** __nstart, _Tp** __nfinish)
    00487     {
    00488       _Tp** __cur;
    00489       try
    00490     {
    00491       for (__cur = __nstart; __cur < __nfinish; ++__cur)
    00492         *__cur = this->_M_allocate_node();
    00493     }
    00494       catch(...)
    00495     {
    00496       _M_destroy_nodes(__nstart, __cur);
    00497       __throw_exception_again;
    00498     }
    00499     }
    00500
    00501   template<typename _Tp, typename _Alloc>
    00502     void
    00503     _Deque_base<_Tp, _Alloc>::
    00504     _M_destroy_nodes(_Tp** __nstart, _Tp** __nfinish)
    00505     {
    00506       for (_Tp** __n = __nstart; __n < __nfinish; ++__n)
    00507     _M_deallocate_node(*__n);
    00508     }
    00509
    00510   /**
    00511    *  @brief  A standard container using fixed-size memory allocation and
    00512    *  constant-time manipulation of elements at either end.
    00513    *
    00514    *  @ingroup Containers
    00515    *  @ingroup Sequences
    00516    *
    00517    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
    00518    *  <a href="tables.html#66">reversible container</a>, and a
    00519    *  <a href="tables.html#67">sequence</a>, including the
    00520    *  <a href="tables.html#68">optional sequence requirements</a>.
    00521    *
    00522    *  In previous HP/SGI versions of deque, there was an extra template
    00523    *  parameter so users could control the node size.  This extension turned
    00524    *  out to violate the C++ standard (it can be detected using template
    00525    *  template parameters), and it was removed.
    00526    *
    00527    *  @if maint
    00528    *  Here's how a deque<Tp> manages memory.  Each deque has 4 members:
    00529    *
    00530    *  - Tp**        _M_map
    00531    *  - size_t      _M_map_size
    00532    *  - iterator    _M_start, _M_finish
    00533    *
    00534    *  map_size is at least 8.  %map is an array of map_size
    00535    *  pointers-to-"nodes".  (The name %map has nothing to do with the
    00536    *  std::map class, and "nodes" should not be confused with
    00537    *  std::list's usage of "node".)
    00538    *
    00539    *  A "node" has no specific type name as such, but it is referred
    00540    *  to as "node" in this file.  It is a simple array-of-Tp.  If Tp
    00541    *  is very large, there will be one Tp element per node (i.e., an
    00542    *  "array" of one).  For non-huge Tp's, node size is inversely
    00543    *  related to Tp size: the larger the Tp, the fewer Tp's will fit
    00544    *  in a node.  The goal here is to keep the total size of a node
    00545    *  relatively small and constant over different Tp's, to improve
    00546    *  allocator efficiency.
    00547    *
    00548    *  Not every pointer in the %map array will point to a node.  If
    00549    *  the initial number of elements in the deque is small, the
    00550    *  /middle/ %map pointers will be valid, and the ones at the edges
    00551    *  will be unused.  This same situation will arise as the %map
    00552    *  grows: available %map pointers, if any, will be on the ends.  As
    00553    *  new nodes are created, only a subset of the %map's pointers need
    00554    *  to be copied "outward".
    00555    *
    00556    *  Class invariants:
    00557    * - For any nonsingular iterator i:
    00558    *    - i.node points to a member of the %map array.  (Yes, you read that
    00559    *      correctly:  i.node does not actually point to a node.)  The member of
    00560    *      the %map array is what actually points to the node.
    00561    *    - i.first == *(i.node)    (This points to the node (first Tp element).)
    00562    *    - i.last  == i.first + node_size
    00563    *    - i.cur is a pointer in the range [i.first, i.last).  NOTE:
    00564    *      the implication of this is that i.cur is always a dereferenceable
    00565    *      pointer, even if i is a past-the-end iterator.
    00566    * - Start and Finish are always nonsingular iterators.  NOTE: this
    00567    * means that an empty deque must have one node, a deque with <N
    00568    * elements (where N is the node buffer size) must have one node, a
    00569    * deque with N through (2N-1) elements must have two nodes, etc.
    00570    * - For every node other than start.node and finish.node, every
    00571    * element in the node is an initialized object.  If start.node ==
    00572    * finish.node, then [start.cur, finish.cur) are initialized
    00573    * objects, and the elements outside that range are uninitialized
    00574    * storage.  Otherwise, [start.cur, start.last) and [finish.first,
    00575    * finish.cur) are initialized objects, and [start.first, start.cur)
    00576    * and [finish.cur, finish.last) are uninitialized storage.
    00577    * - [%map, %map + map_size) is a valid, non-empty range.
    00578    * - [start.node, finish.node] is a valid range contained within
    00579    *   [%map, %map + map_size).
    00580    * - A pointer in the range [%map, %map + map_size) points to an allocated
    00581    *   node if and only if the pointer is in the range
    00582    *   [start.node, finish.node].
    00583    *
    00584    *  Here's the magic:  nothing in deque is "aware" of the discontiguous
    00585    *  storage!
    00586    *
    00587    *  The memory setup and layout occurs in the parent, _Base, and the iterator
    00588    *  class is entirely responsible for "leaping" from one node to the next.
    00589    *  All the implementation routines for deque itself work only through the
    00590    *  start and finish iterators.  This keeps the routines simple and sane,
    00591    *  and we can use other standard algorithms as well.
    00592    *  @endif
    00593   */
    00594   template<typename _Tp, typename _Alloc = allocator<_Tp> >
    00595     class deque : protected _Deque_base<_Tp, _Alloc>
    00596     {
    00597       // concept requirements
    00598       __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
    00599
    00600       typedef _Deque_base<_Tp, _Alloc>           _Base;
    00601
    00602     public:
    00603       typedef _Tp                                value_type;
    00604       typedef typename _Alloc::pointer           pointer;
    00605       typedef typename _Alloc::const_pointer     const_pointer;
    00606       typedef typename _Alloc::reference         reference;
    00607       typedef typename _Alloc::const_reference   const_reference;
    00608       typedef typename _Base::iterator           iterator;
    00609       typedef typename _Base::const_iterator     const_iterator;
    00610       typedef std::reverse_iterator<const_iterator>   const_reverse_iterator;
    00611       typedef std::reverse_iterator<iterator>         reverse_iterator;
    00612       typedef size_t                             size_type;
    00613       typedef ptrdiff_t                          difference_type;
    00614       typedef typename _Base::allocator_type     allocator_type;
    00615
    00616     protected:
    00617       typedef pointer*                           _Map_pointer;
    00618
    00619       static size_t _S_buffer_size()
    00620       { return __deque_buf_size(sizeof(_Tp)); }
    00621
    00622       // Functions controlling memory layout, and nothing else.
    00623       using _Base::_M_initialize_map;
    00624       using _Base::_M_create_nodes;
    00625       using _Base::_M_destroy_nodes;
    00626       using _Base::_M_allocate_node;
    00627       using _Base::_M_deallocate_node;
    00628       using _Base::_M_allocate_map;
    00629       using _Base::_M_deallocate_map;
    00630
    00631       /** @if maint
    00632        *  A total of four data members accumulated down the heirarchy.
    00633        *  May be accessed via _M_impl.*
    00634        *  @endif
    00635        */
    00636       using _Base::_M_impl;
    00637
    00638     public:
    00639       // [23.2.1.1] construct/copy/destroy
    00640       // (assign() and get_allocator() are also listed in this section)
    00641       /**
    00642        *  @brief  Default constructor creates no elements.
    00643        */
    00644       explicit
    00645       deque(const allocator_type& __a = allocator_type())
    00646       : _Base(__a, 0) {}
    00647
    00648       /**
    00649        *  @brief  Create a %deque with copies of an exemplar element.
    00650        *  @param  n  The number of elements to initially create.
    00651        *  @param  value  An element to copy.
    00652        *
    00653        *  This constructor fills the %deque with @a n copies of @a value.
    00654        */
    00655       deque(size_type __n, const value_type& __value,
    00656         const allocator_type& __a = allocator_type())
    00657       : _Base(__a, __n)
    00658       { _M_fill_initialize(__value); }
    00659
    00660       /**
    00661        *  @brief  Create a %deque with default elements.
    00662        *  @param  n  The number of elements to initially create.
    00663        *
    00664        *  This constructor fills the %deque with @a n copies of a
    00665        *  default-constructed element.
    00666        */
    00667       explicit
    00668       deque(size_type __n)
    00669       : _Base(allocator_type(), __n)
    00670       { _M_fill_initialize(value_type()); }
    00671
    00672       /**
    00673        *  @brief  %Deque copy constructor.
    00674        *  @param  x  A %deque of identical element and allocator types.
    00675        *
    00676        *  The newly-created %deque uses a copy of the allocation object used
    00677        *  by @a x.
    00678        */
    00679       deque(const deque& __x)
    00680       : _Base(__x.get_allocator(), __x.size())
    00681       { std::__uninitialized_copy_a(__x.begin(), __x.end(),
    00682                     this->_M_impl._M_start,
    00683                     this->get_allocator()); }
    00684
    00685       /**
    00686        *  @brief  Builds a %deque from a range.
    00687        *  @param  first  An input iterator.
    00688        *  @param  last  An input iterator.
    00689        *
    00690        *  Create a %deque consisting of copies of the elements from [first,
    00691        *  last).
    00692        *
    00693        *  If the iterators are forward, bidirectional, or random-access, then
    00694        *  this will call the elements' copy constructor N times (where N is
    00695        *  distance(first,last)) and do no memory reallocation.  But if only
    00696        *  input iterators are used, then this will do at most 2N calls to the
    00697        *  copy constructor, and logN memory reallocations.
    00698        */
    00699       template<typename _InputIterator>
    00700         deque(_InputIterator __first, _InputIterator __last,
    00701           const allocator_type& __a = allocator_type())
    00702     : _Base(__a)
    00703         {
    00704       // Check whether it's an integral type.  If so, it's not an iterator.
    00705       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
    00706       _M_initialize_dispatch(__first, __last, _Integral());
    00707     }
    00708
    00709       /**
    00710        *  The dtor only erases the elements, and note that if the elements
    00711        *  themselves are pointers, the pointed-to memory is not touched in any
    00712        *  way.  Managing the pointer is the user's responsibilty.
    00713        */
    00714       ~deque()
    00715       { std::_Destroy(this->_M_impl._M_start, this->_M_impl._M_finish,
    00716               this->get_allocator()); }
    00717
    00718       /**
    00719        *  @brief  %Deque assignment operator.
    00720        *  @param  x  A %deque of identical element and allocator types.
    00721        *
    00722        *  All the elements of @a x are copied, but unlike the copy constructor,
    00723        *  the allocator object is not copied.
    00724        */
    00725       deque&
    00726       operator=(const deque& __x);
    00727
    00728       /**
    00729        *  @brief  Assigns a given value to a %deque.
    00730        *  @param  n  Number of elements to be assigned.
    00731        *  @param  val  Value to be assigned.
    00732        *
    00733        *  This function fills a %deque with @a n copies of the given
    00734        *  value.  Note that the assignment completely changes the
    00735        *  %deque and that the resulting %deque's size is the same as
    00736        *  the number of elements assigned.  Old data may be lost.
    00737        */
    00738       void
    00739       assign(size_type __n, const value_type& __val)
    00740       { _M_fill_assign(__n, __val); }
    00741
    00742       /**
    00743        *  @brief  Assigns a range to a %deque.
    00744        *  @param  first  An input iterator.
    00745        *  @param  last   An input iterator.
    00746        *
    00747        *  This function fills a %deque with copies of the elements in the
    00748        *  range [first,last).
    00749        *
    00750        *  Note that the assignment completely changes the %deque and that the
    00751        *  resulting %deque's size is the same as the number of elements
    00752        *  assigned.  Old data may be lost.
    00753        */
    00754       template<typename _InputIterator>
    00755         void
    00756         assign(_InputIterator __first, _InputIterator __last)
    00757         {
    00758       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
    00759       _M_assign_dispatch(__first, __last, _Integral());
    00760     }
    00761
    00762       /// Get a copy of the memory allocation object.
    00763       allocator_type
    00764       get_allocator() const
    00765       { return _Base::get_allocator(); }
    00766
    00767       // iterators
    00768       /**
    00769        *  Returns a read/write iterator that points to the first element in the
    00770        *  %deque.  Iteration is done in ordinary element order.
    00771        */
    00772       iterator
    00773       begin()
    00774       { return this->_M_impl._M_start; }
    00775
    00776       /**
    00777        *  Returns a read-only (constant) iterator that points to the first
    00778        *  element in the %deque.  Iteration is done in ordinary element order.
    00779        */
    00780       const_iterator
    00781       begin() const
    00782       { return this->_M_impl._M_start; }
    00783
    00784       /**
    00785        *  Returns a read/write iterator that points one past the last
    00786        *  element in the %deque.  Iteration is done in ordinary
    00787        *  element order.
    00788        */
    00789       iterator
    00790       end()
    00791       { return this->_M_impl._M_finish; }
    00792
    00793       /**
    00794        *  Returns a read-only (constant) iterator that points one past
    00795        *  the last element in the %deque.  Iteration is done in
    00796        *  ordinary element order.
    00797        */
    00798       const_iterator
    00799       end() const
    00800       { return this->_M_impl._M_finish; }
    00801
    00802       /**
    00803        *  Returns a read/write reverse iterator that points to the
    00804        *  last element in the %deque.  Iteration is done in reverse
    00805        *  element order.
    00806        */
    00807       reverse_iterator
    00808       rbegin()
    00809       { return reverse_iterator(this->_M_impl._M_finish); }
    00810
    00811       /**
    00812        *  Returns a read-only (constant) reverse iterator that points
    00813        *  to the last element in the %deque.  Iteration is done in
    00814        *  reverse element order.
    00815        */
    00816       const_reverse_iterator
    00817       rbegin() const
    00818       { return const_reverse_iterator(this->_M_impl._M_finish); }
    00819
    00820       /**
    00821        *  Returns a read/write reverse iterator that points to one
    00822        *  before the first element in the %deque.  Iteration is done
    00823        *  in reverse element order.
    00824        */
    00825       reverse_iterator
    00826       rend() { return reverse_iterator(this->_M_impl._M_start); }
    00827
    00828       /**
    00829        *  Returns a read-only (constant) reverse iterator that points
    00830        *  to one before the first element in the %deque.  Iteration is
    00831        *  done in reverse element order.
    00832        */
    00833       const_reverse_iterator
    00834       rend() const
    00835       { return const_reverse_iterator(this->_M_impl._M_start); }
    00836
    00837       // [23.2.1.2] capacity
    00838       /**  Returns the number of elements in the %deque.  */
    00839       size_type
    00840       size() const
    00841       { return this->_M_impl._M_finish - this->_M_impl._M_start; }
    00842
    00843       /**  Returns the size() of the largest possible %deque.  */
    00844       size_type
    00845       max_size() const
    00846       { return size_type(-1); }
    00847
    00848       /**
    00849        *  @brief  Resizes the %deque to the specified number of elements.
    00850        *  @param  new_size  Number of elements the %deque should contain.
    00851        *  @param  x  Data with which new elements should be populated.
    00852        *
    00853        *  This function will %resize the %deque to the specified
    00854        *  number of elements.  If the number is smaller than the
    00855        *  %deque's current size the %deque is truncated, otherwise the
    00856        *  %deque is extended and new elements are populated with given
    00857        *  data.
    00858        */
    00859       void
    00860       resize(size_type __new_size, const value_type& __x)
    00861       {
    00862     const size_type __len = size();
    00863     if (__new_size < __len)
    00864       erase(this->_M_impl._M_start + __new_size, this->_M_impl._M_finish);
    00865     else
    00866       insert(this->_M_impl._M_finish, __new_size - __len, __x);
    00867       }
    00868
    00869       /**
    00870        *  @brief  Resizes the %deque to the specified number of elements.
    00871        *  @param  new_size  Number of elements the %deque should contain.
    00872        *
    00873        *  This function will resize the %deque to the specified number
    00874        *  of elements.  If the number is smaller than the %deque's
    00875        *  current size the %deque is truncated, otherwise the %deque
    00876        *  is extended and new elements are default-constructed.
    00877        */
    00878       void
    00879       resize(size_type new_size)
    00880       { resize(new_size, value_type()); }
    00881
    00882       /**
    00883        *  Returns true if the %deque is empty.  (Thus begin() would
    00884        *  equal end().)
    00885        */
    00886       bool
    00887       empty() const
    00888       { return this->_M_impl._M_finish == this->_M_impl._M_start; }
    00889
    00890       // element access
    00891       /**
    00892        *  @brief Subscript access to the data contained in the %deque.
    00893        *  @param n The index of the element for which data should be
    00894        *  accessed.
    00895        *  @return  Read/write reference to data.
    00896        *
    00897        *  This operator allows for easy, array-style, data access.
    00898        *  Note that data access with this operator is unchecked and
    00899        *  out_of_range lookups are not defined. (For checked lookups
    00900        *  see at().)
    00901        */
    00902       reference
    00903       operator[](size_type __n)
    00904       { return this->_M_impl._M_start[difference_type(__n)]; }
    00905
    00906       /**
    00907        *  @brief Subscript access to the data contained in the %deque.
    00908        *  @param n The index of the element for which data should be
    00909        *  accessed.
    00910        *  @return  Read-only (constant) reference to data.
    00911        *
    00912        *  This operator allows for easy, array-style, data access.
    00913        *  Note that data access with this operator is unchecked and
    00914        *  out_of_range lookups are not defined. (For checked lookups
    00915        *  see at().)
    00916        */
    00917       const_reference
    00918       operator[](size_type __n) const
    00919       { return this->_M_impl._M_start[difference_type(__n)]; }
    00920
    00921     protected:
    00922       /// @if maint Safety check used only from at().  @endif
    00923       void
    00924       _M_range_check(size_type __n) const
    00925       {
    00926     if (__n >= this->size())
    00927       __throw_out_of_range(__N("deque::_M_range_check"));
    00928       }
    00929
    00930     public:
    00931       /**
    00932        *  @brief  Provides access to the data contained in the %deque.
    00933        *  @param n The index of the element for which data should be
    00934        *  accessed.
    00935        *  @return  Read/write reference to data.
    00936        *  @throw  std::out_of_range  If @a n is an invalid index.
    00937        *
    00938        *  This function provides for safer data access.  The parameter
    00939        *  is first checked that it is in the range of the deque.  The
    00940        *  function throws out_of_range if the check fails.
    00941        */
    00942       reference
    00943       at(size_type __n)
    00944       {
    00945     _M_range_check(__n);
    00946     return (*this)[__n];
    00947       }
    00948
    00949       /**
    00950        *  @brief  Provides access to the data contained in the %deque.
    00951        *  @param n The index of the element for which data should be
    00952        *  accessed.
    00953        *  @return  Read-only (constant) reference to data.
    00954        *  @throw  std::out_of_range  If @a n is an invalid index.
    00955        *
    00956        *  This function provides for safer data access.  The parameter is first
    00957        *  checked that it is in the range of the deque.  The function throws
    00958        *  out_of_range if the check fails.
    00959        */
    00960       const_reference
    00961       at(size_type __n) const
    00962       {
    00963     _M_range_check(__n);
    00964     return (*this)[__n];
    00965       }
    00966
    00967       /**
    00968        *  Returns a read/write reference to the data at the first
    00969        *  element of the %deque.
    00970        */
    00971       reference
    00972       front()
    00973       { return *begin(); }
    00974
    00975       /**
    00976        *  Returns a read-only (constant) reference to the data at the first
    00977        *  element of the %deque.
    00978        */
    00979       const_reference
    00980       front() const
    00981       { return *begin(); }
    00982
    00983       /**
    00984        *  Returns a read/write reference to the data at the last element of the
    00985        *  %deque.
    00986        */
    00987       reference
    00988       back()
    00989       {
    00990     iterator __tmp = end();
    00991     --__tmp;
    00992     return *__tmp;
    00993       }
    00994
    00995       /**
    00996        *  Returns a read-only (constant) reference to the data at the last
    00997        *  element of the %deque.
    00998        */
    00999       const_reference
    01000       back() const
    01001       {
    01002     const_iterator __tmp = end();
    01003     --__tmp;
    01004     return *__tmp;
    01005       }
    01006
    01007       // [23.2.1.2] modifiers
    01008       /**
    01009        *  @brief  Add data to the front of the %deque.
    01010        *  @param  x  Data to be added.
    01011        *
    01012        *  This is a typical stack operation.  The function creates an
    01013        *  element at the front of the %deque and assigns the given
    01014        *  data to it.  Due to the nature of a %deque this operation
    01015        *  can be done in constant time.
    01016        */
    01017       void
    01018       push_front(const value_type& __x)
    01019       {
    01020     if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_first)
    01021       {
    01022         this->_M_impl.construct(this->_M_impl._M_start._M_cur - 1, __x);
    01023         --this->_M_impl._M_start._M_cur;
    01024       }
    01025     else
    01026       _M_push_front_aux(__x);
    01027       }
    01028
    01029       /**
    01030        *  @brief  Add data to the end of the %deque.
    01031        *  @param  x  Data to be added.
    01032        *
    01033        *  This is a typical stack operation.  The function creates an
    01034        *  element at the end of the %deque and assigns the given data
    01035        *  to it.  Due to the nature of a %deque this operation can be
    01036        *  done in constant time.
    01037        */
    01038       void
    01039       push_back(const value_type& __x)
    01040       {
    01041     if (this->_M_impl._M_finish._M_cur
    01042         != this->_M_impl._M_finish._M_last - 1)
    01043       {
    01044         this->_M_impl.construct(this->_M_impl._M_finish._M_cur, __x);
    01045         ++this->_M_impl._M_finish._M_cur;
    01046       }
    01047     else
    01048       _M_push_back_aux(__x);
    01049       }
    01050
    01051       /**
    01052        *  @brief  Removes first element.
    01053        *
    01054        *  This is a typical stack operation.  It shrinks the %deque by one.
    01055        *
    01056        *  Note that no data is returned, and if the first element's data is
    01057        *  needed, it should be retrieved before pop_front() is called.
    01058        */
    01059       void
    01060       pop_front()
    01061       {
    01062     if (this->_M_impl._M_start._M_cur
    01063         != this->_M_impl._M_start._M_last - 1)
    01064       {
    01065         this->_M_impl.destroy(this->_M_impl._M_start._M_cur);
    01066         ++this->_M_impl._M_start._M_cur;
    01067       }
    01068     else
    01069       _M_pop_front_aux();
    01070       }
    01071
    01072       /**
    01073        *  @brief  Removes last element.
    01074        *
    01075        *  This is a typical stack operation.  It shrinks the %deque by one.
    01076        *
    01077        *  Note that no data is returned, and if the last element's data is
    01078        *  needed, it should be retrieved before pop_back() is called.
    01079        */
    01080       void
    01081       pop_back()
    01082       {
    01083     if (this->_M_impl._M_finish._M_cur
    01084         != this->_M_impl._M_finish._M_first)
    01085       {
    01086         --this->_M_impl._M_finish._M_cur;
    01087         this->_M_impl.destroy(this->_M_impl._M_finish._M_cur);
    01088       }
    01089     else
    01090       _M_pop_back_aux();
    01091       }
    01092
    01093       /**
    01094        *  @brief  Inserts given value into %deque before specified iterator.
    01095        *  @param  position  An iterator into the %deque.
    01096        *  @param  x  Data to be inserted.
    01097        *  @return  An iterator that points to the inserted data.
    01098        *
    01099        *  This function will insert a copy of the given value before the
    01100        *  specified location.
    01101        */
    01102       iterator
    01103       insert(iterator position, const value_type& __x);
    01104
    01105       /**
    01106        *  @brief  Inserts a number of copies of given data into the %deque.
    01107        *  @param  position  An iterator into the %deque.
    01108        *  @param  n  Number of elements to be inserted.
    01109        *  @param  x  Data to be inserted.
    01110        *
    01111        *  This function will insert a specified number of copies of the given
    01112        *  data before the location specified by @a position.
    01113        */
    01114       void
    01115       insert(iterator __position, size_type __n, const value_type& __x)
    01116       { _M_fill_insert(__position, __n, __x); }
    01117
    01118       /**
    01119        *  @brief  Inserts a range into the %deque.
    01120        *  @param  position  An iterator into the %deque.
    01121        *  @param  first  An input iterator.
    01122        *  @param  last   An input iterator.
    01123        *
    01124        *  This function will insert copies of the data in the range
    01125        *  [first,last) into the %deque before the location specified
    01126        *  by @a pos.  This is known as "range insert."
    01127        */
    01128       template<typename _InputIterator>
    01129         void
    01130         insert(iterator __position, _InputIterator __first,
    01131            _InputIterator __last)
    01132         {
    01133       // Check whether it's an integral type.  If so, it's not an iterator.
    01134       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
    01135       _M_insert_dispatch(__position, __first, __last, _Integral());
    01136     }
    01137
    01138       /**
    01139        *  @brief  Remove element at given position.
    01140        *  @param  position  Iterator pointing to element to be erased.
    01141        *  @return  An iterator pointing to the next element (or end()).
    01142        *
    01143        *  This function will erase the element at the given position and thus
    01144        *  shorten the %deque by one.
    01145        *
    01146        *  The user is cautioned that
    01147        *  this function only erases the element, and that if the element is
    01148        *  itself a pointer, the pointed-to memory is not touched in any way.
    01149        *  Managing the pointer is the user's responsibilty.
    01150        */
    01151       iterator
    01152       erase(iterator __position);
    01153
    01154       /**
    01155        *  @brief  Remove a range of elements.
    01156        *  @param  first  Iterator pointing to the first element to be erased.
    01157        *  @param  last  Iterator pointing to one past the last element to be
    01158        *                erased.
    01159        *  @return  An iterator pointing to the element pointed to by @a last
    01160        *           prior to erasing (or end()).
    01161        *
    01162        *  This function will erase the elements in the range [first,last) and
    01163        *  shorten the %deque accordingly.
    01164        *
    01165        *  The user is cautioned that
    01166        *  this function only erases the elements, and that if the elements
    01167        *  themselves are pointers, the pointed-to memory is not touched in any
    01168        *  way.  Managing the pointer is the user's responsibilty.
    01169        */
    01170       iterator
    01171       erase(iterator __first, iterator __last);
    01172
    01173       /**
    01174        *  @brief  Swaps data with another %deque.
    01175        *  @param  x  A %deque of the same element and allocator types.
    01176        *
    01177        *  This exchanges the elements between two deques in constant time.
    01178        *  (Four pointers, so it should be quite fast.)
    01179        *  Note that the global std::swap() function is specialized such that
    01180        *  std::swap(d1,d2) will feed to this function.
    01181        */
    01182       void
    01183       swap(deque& __x)
    01184       {
    01185     std::swap(this->_M_impl._M_start, __x._M_impl._M_start);
    01186     std::swap(this->_M_impl._M_finish, __x._M_impl._M_finish);
    01187     std::swap(this->_M_impl._M_map, __x._M_impl._M_map);
    01188     std::swap(this->_M_impl._M_map_size, __x._M_impl._M_map_size);
    01189       }
    01190
    01191       /**
    01192        *  Erases all the elements.  Note that this function only erases the
    01193        *  elements, and that if the elements themselves are pointers, the
    01194        *  pointed-to memory is not touched in any way.  Managing the pointer is
    01195        *  the user's responsibilty.
    01196        */
    01197       void clear();
    01198
    01199     protected:
    01200       // Internal constructor functions follow.
    01201
    01202       // called by the range constructor to implement [23.1.1]/9
    01203       template<typename _Integer>
    01204         void
    01205         _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type)
    01206         {
    01207       _M_initialize_map(__n);
    01208       _M_fill_initialize(__x);
    01209     }
    01210
    01211       // called by the range constructor to implement [23.1.1]/9
    01212       template<typename _InputIterator>
    01213         void
    01214         _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
    01215                    __false_type)
    01216         {
    01217       typedef typename iterator_traits<_InputIterator>::iterator_category
    01218         _IterCategory;
    01219       _M_range_initialize(__first, __last, _IterCategory());
    01220     }
    01221
    01222       // called by the second initialize_dispatch above
    01223       //@{
    01224       /**
    01225        *  @if maint
    01226        *  @brief Fills the deque with whatever is in [first,last).
    01227        *  @param  first  An input iterator.
    01228        *  @param  last  An input iterator.
    01229        *  @return   Nothing.
    01230        *
    01231        *  If the iterators are actually forward iterators (or better), then the
    01232        *  memory layout can be done all at once.  Else we move forward using
    01233        *  push_back on each value from the iterator.
    01234        *  @endif
    01235        */
    01236       template<typename _InputIterator>
    01237         void
    01238         _M_range_initialize(_InputIterator __first, _InputIterator __last,
    01239                 input_iterator_tag);
    01240
    01241       // called by the second initialize_dispatch above
    01242       template<typename _ForwardIterator>
    01243         void
    01244         _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last,
    01245                 forward_iterator_tag);
    01246       //@}
    01247
    01248       /**
    01249        *  @if maint
    01250        *  @brief Fills the %deque with copies of value.
    01251        *  @param  value  Initial value.
    01252        *  @return   Nothing.
    01253        *  @pre _M_start and _M_finish have already been initialized,
    01254        *  but none of the %deque's elements have yet been constructed.
    01255        *
    01256        *  This function is called only when the user provides an explicit size
    01257        *  (with or without an explicit exemplar value).
    01258        *  @endif
    01259        */
    01260       void
    01261       _M_fill_initialize(const value_type& __value);
    01262
    01263       // Internal assign functions follow.  The *_aux functions do the actual
    01264       // assignment work for the range versions.
    01265
    01266       // called by the range assign to implement [23.1.1]/9
    01267       template<typename _Integer>
    01268         void
    01269         _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
    01270         {
    01271       _M_fill_assign(static_cast<size_type>(__n),
    01272              static_cast<value_type>(__val));
    01273     }
    01274
    01275       // called by the range assign to implement [23.1.1]/9
    01276       template<typename _InputIterator>
    01277         void
    01278         _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
    01279                __false_type)
    01280         {
    01281       typedef typename iterator_traits<_InputIterator>::iterator_category
    01282         _IterCategory;
    01283       _M_assign_aux(__first, __last, _IterCategory());
    01284     }
    01285
    01286       // called by the second assign_dispatch above
    01287       template<typename _InputIterator>
    01288         void
    01289         _M_assign_aux(_InputIterator __first, _InputIterator __last,
    01290               input_iterator_tag);
    01291
    01292       // called by the second assign_dispatch above
    01293       template<typename _ForwardIterator>
    01294         void
    01295         _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,
    01296               forward_iterator_tag)
    01297         {
    01298       const size_type __len = std::distance(__first, __last);
    01299       if (__len > size())
    01300         {
    01301           _ForwardIterator __mid = __first;
    01302           std::advance(__mid, size());
    01303           std::copy(__first, __mid, begin());
    01304           insert(end(), __mid, __last);
    01305         }
    01306       else
    01307         erase(std::copy(__first, __last, begin()), end());
    01308     }
    01309
    01310       // Called by assign(n,t), and the range assign when it turns out
    01311       // to be the same thing.
    01312       void
    01313       _M_fill_assign(size_type __n, const value_type& __val)
    01314       {
    01315     if (__n > size())
    01316       {
    01317         std::fill(begin(), end(), __val);
    01318         insert(end(), __n - size(), __val);
    01319       }
    01320     else
    01321       {
    01322         erase(begin() + __n, end());
    01323         std::fill(begin(), end(), __val);
    01324       }
    01325       }
    01326
    01327       //@{
    01328       /**
    01329        *  @if maint
    01330        *  @brief Helper functions for push_* and pop_*.
    01331        *  @endif
    01332        */
    01333       void _M_push_back_aux(const value_type&);
    01334       void _M_push_front_aux(const value_type&);
    01335       void _M_pop_back_aux();
    01336       void _M_pop_front_aux();
    01337       //@}
    01338
    01339       // Internal insert functions follow.  The *_aux functions do the actual
    01340       // insertion work when all shortcuts fail.
    01341
    01342       // called by the range insert to implement [23.1.1]/9
    01343       template<typename _Integer>
    01344         void
    01345         _M_insert_dispatch(iterator __pos,
    01346                _Integer __n, _Integer __x, __true_type)
    01347         {
    01348       _M_fill_insert(__pos, static_cast<size_type>(__n),
    01349              static_cast<value_type>(__x));
    01350     }
    01351
    01352       // called by the range insert to implement [23.1.1]/9
    01353       template<typename _InputIterator>
    01354         void
    01355         _M_insert_dispatch(iterator __pos,
    01356                _InputIterator __first, _InputIterator __last,
    01357                __false_type)
    01358         {
    01359       typedef typename iterator_traits<_InputIterator>::iterator_category
    01360         _IterCategory;
    01361           _M_range_insert_aux(__pos, __first, __last, _IterCategory());
    01362     }
    01363
    01364       // called by the second insert_dispatch above
    01365       template<typename _InputIterator>
    01366         void
    01367         _M_range_insert_aux(iterator __pos, _InputIterator __first,
    01368                 _InputIterator __last, input_iterator_tag);
    01369
    01370       // called by the second insert_dispatch above
    01371       template<typename _ForwardIterator>
    01372         void
    01373         _M_range_insert_aux(iterator __pos, _ForwardIterator __first,
    01374                 _ForwardIterator __last, forward_iterator_tag);
    01375
    01376       // Called by insert(p,n,x), and the range insert when it turns out to be
    01377       // the same thing.  Can use fill functions in optimal situations,
    01378       // otherwise passes off to insert_aux(p,n,x).
    01379       void
    01380       _M_fill_insert(iterator __pos, size_type __n, const value_type& __x);
    01381
    01382       // called by insert(p,x)
    01383       iterator
    01384       _M_insert_aux(iterator __pos, const value_type& __x);
    01385
    01386       // called by insert(p,n,x) via fill_insert
    01387       void
    01388       _M_insert_aux(iterator __pos, size_type __n, const value_type& __x);
    01389
    01390       // called by range_insert_aux for forward iterators
    01391       template<typename _ForwardIterator>
    01392         void
    01393         _M_insert_aux(iterator __pos,
    01394               _ForwardIterator __first, _ForwardIterator __last,
    01395               size_type __n);
    01396
    01397       //@{
    01398       /**
    01399        *  @if maint
    01400        *  @brief Memory-handling helpers for the previous internal insert
    01401        *         functions.
    01402        *  @endif
    01403        */
    01404       iterator
    01405       _M_reserve_elements_at_front(size_type __n)
    01406       {
    01407     const size_type __vacancies = this->_M_impl._M_start._M_cur
    01408                                   - this->_M_impl._M_start._M_first;
    01409     if (__n > __vacancies)
    01410       _M_new_elements_at_front(__n - __vacancies);
    01411     return this->_M_impl._M_start - difference_type(__n);
    01412       }
    01413
    01414       iterator
    01415       _M_reserve_elements_at_back(size_type __n)
    01416       {
    01417     const size_type __vacancies = (this->_M_impl._M_finish._M_last
    01418                        - this->_M_impl._M_finish._M_cur) - 1;
    01419     if (__n > __vacancies)
    01420       _M_new_elements_at_back(__n - __vacancies);
    01421     return this->_M_impl._M_finish + difference_type(__n);
    01422       }
    01423
    01424       void
    01425       _M_new_elements_at_front(size_type __new_elements);
    01426
    01427       void
    01428       _M_new_elements_at_back(size_type __new_elements);
    01429       //@}
    01430
    01431
    01432       //@{
    01433       /**
    01434        *  @if maint
    01435        *  @brief Memory-handling helpers for the major %map.
    01436        *
    01437        *  Makes sure the _M_map has space for new nodes.  Does not
    01438        *  actually add the nodes.  Can invalidate _M_map pointers.
    01439        *  (And consequently, %deque iterators.)
    01440        *  @endif
    01441        */
    01442       void
    01443       _M_reserve_map_at_back (size_type __nodes_to_add = 1)
    01444       {
    01445     if (__nodes_to_add + 1 > this->_M_impl._M_map_size
    01446         - (this->_M_impl._M_finish._M_node - this->_M_impl._M_map))
    01447       _M_reallocate_map(__nodes_to_add, false);
    01448       }
    01449
    01450       void
    01451       _M_reserve_map_at_front (size_type __nodes_to_add = 1)
    01452       {
    01453     if (__nodes_to_add > size_type(this->_M_impl._M_start._M_node
    01454                        - this->_M_impl._M_map))
    01455       _M_reallocate_map(__nodes_to_add, true);
    01456       }
    01457
    01458       void
    01459       _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front);
    01460       //@}
    01461     };
    01462
    01463
    01464   /**
    01465    *  @brief  Deque equality comparison.
    01466    *  @param  x  A %deque.
    01467    *  @param  y  A %deque of the same type as @a x.
    01468    *  @return  True iff the size and elements of the deques are equal.
    01469    *
    01470    *  This is an equivalence relation.  It is linear in the size of the
    01471    *  deques.  Deques are considered equivalent if their sizes are equal,
    01472    *  and if corresponding elements compare equal.
    01473   */
    01474   template<typename _Tp, typename _Alloc>
    01475     inline bool
    01476     operator==(const deque<_Tp, _Alloc>& __x,
    01477                          const deque<_Tp, _Alloc>& __y)
    01478     { return __x.size() == __y.size()
    01479              && std::equal(__x.begin(), __x.end(), __y.begin()); }
    01480
    01481   /**
    01482    *  @brief  Deque ordering relation.
    01483    *  @param  x  A %deque.
    01484    *  @param  y  A %deque of the same type as @a x.
    01485    *  @return  True iff @a x is lexicographically less than @a y.
    01486    *
    01487    *  This is a total ordering relation.  It is linear in the size of the
    01488    *  deques.  The elements must be comparable with @c <.
    01489    *
    01490    *  See std::lexicographical_compare() for how the determination is made.
    01491   */
    01492   template<typename _Tp, typename _Alloc>
    01493     inline bool
    01494     operator<(const deque<_Tp, _Alloc>& __x,
    01495           const deque<_Tp, _Alloc>& __y)
    01496     { return lexicographical_compare(__x.begin(), __x.end(),
    01497                      __y.begin(), __y.end()); }
    01498
    01499   /// Based on operator==
    01500   template<typename _Tp, typename _Alloc>
    01501     inline bool
    01502     operator!=(const deque<_Tp, _Alloc>& __x,
    01503            const deque<_Tp, _Alloc>& __y)
    01504     { return !(__x == __y); }
    01505
    01506   /// Based on operator<
    01507   template<typename _Tp, typename _Alloc>
    01508     inline bool
    01509     operator>(const deque<_Tp, _Alloc>& __x,
    01510           const deque<_Tp, _Alloc>& __y)
    01511     { return __y < __x; }
    01512
    01513   /// Based on operator<
    01514   template<typename _Tp, typename _Alloc>
    01515     inline bool
    01516     operator<=(const deque<_Tp, _Alloc>& __x,
    01517            const deque<_Tp, _Alloc>& __y)
    01518     { return !(__y < __x); }
    01519
    01520   /// Based on operator<
    01521   template<typename _Tp, typename _Alloc>
    01522     inline bool
    01523     operator>=(const deque<_Tp, _Alloc>& __x,
    01524            const deque<_Tp, _Alloc>& __y)
    01525     { return !(__x < __y); }
    01526
    01527   /// See std::deque::swap().
    01528   template<typename _Tp, typename _Alloc>
    01529     inline void
    01530     swap(deque<_Tp,_Alloc>& __x, deque<_Tp,_Alloc>& __y)
    01531     { __x.swap(__y); }
    01532 } // namespace std
    01533
    01534 #endif /* _DEQUE_H */