# stl_deque.h

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    00001 // Deque implementation -*- C++ -*-
    00002
    00003 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006
    00004 // Free Software Foundation, Inc.
    00005 //
    00006 // This file is part of the GNU ISO C++ Library.  This library is free
    00007 // software; you can redistribute it and/or modify it under the
    00008 // terms of the GNU General Public License as published by the
    00009 // Free Software Foundation; either version 2, or (at your option)
    00010 // any later version.
    00011
    00012 // This library is distributed in the hope that it will be useful,
    00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00015 // GNU General Public License for more details.
    00016
    00017 // You should have received a copy of the GNU General Public License along
    00018 // with this library; see the file COPYING.  If not, write to the Free
    00019 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
    00020 // USA.
    00021
    00022 // As a special exception, you may use this file as part of a free software
    00023 // library without restriction.  Specifically, if other files instantiate
    00024 // templates or use macros or inline functions from this file, or you compile
    00025 // this file and link it with other files to produce an executable, this
    00026 // file does not by itself cause the resulting executable to be covered by
    00027 // the GNU General Public License.  This exception does not however
    00028 // invalidate any other reasons why the executable file might be covered by
    00029 // the GNU General Public License.
    00030
    00031 /*
    00032  *
    00033  * Copyright (c) 1994
    00034  * Hewlett-Packard Company
    00035  *
    00036  * Permission to use, copy, modify, distribute and sell this software
    00037  * and its documentation for any purpose is hereby granted without fee,
    00038  * provided that the above copyright notice appear in all copies and
    00039  * that both that copyright notice and this permission notice appear
    00040  * in supporting documentation.  Hewlett-Packard Company makes no
    00041  * representations about the suitability of this software for any
    00042  * purpose.  It is provided "as is" without express or implied warranty.
    00043  *
    00044  *
    00045  * Copyright (c) 1997
    00046  * Silicon Graphics Computer Systems, Inc.
    00047  *
    00048  * Permission to use, copy, modify, distribute and sell this software
    00049  * and its documentation for any purpose is hereby granted without fee,
    00050  * provided that the above copyright notice appear in all copies and
    00051  * that both that copyright notice and this permission notice appear
    00052  * in supporting documentation.  Silicon Graphics makes no
    00053  * representations about the suitability of this software for any
    00054  * purpose.  It is provided "as is" without express or implied warranty.
    00055  */
    00056
    00057 /** @file stl_deque.h
    00058  *  This is an internal header file, included by other library headers.
    00059  *  You should not attempt to use it directly.
    00060  */
    00061
    00062 #ifndef _DEQUE_H
    00063 #define _DEQUE_H 1
    00064
    00065 #include <bits/concept_check.h>
    00066 #include <bits/stl_iterator_base_types.h>
    00067 #include <bits/stl_iterator_base_funcs.h>
    00068
    00069 _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD)
    00070
    00071   /**
    00072    *  @if maint
    00073    *  @brief This function controls the size of memory nodes.
    00074    *  @param  size  The size of an element.
    00075    *  @return   The number (not byte size) of elements per node.
    00076    *
    00077    *  This function started off as a compiler kludge from SGI, but seems to
    00078    *  be a useful wrapper around a repeated constant expression.  The '512' is
    00079    *  tuneable (and no other code needs to change), but no investigation has
    00080    *  been done since inheriting the SGI code.
    00081    *  @endif
    00082   */
    00083   inline size_t
    00084   __deque_buf_size(size_t __size)
    00085   { return __size < 512 ? size_t(512 / __size) : size_t(1); }
    00086
    00087
    00088   /**
    00089    *  @brief A deque::iterator.
    00090    *
    00091    *  Quite a bit of intelligence here.  Much of the functionality of
    00092    *  deque is actually passed off to this class.  A deque holds two
    00093    *  of these internally, marking its valid range.  Access to
    00094    *  elements is done as offsets of either of those two, relying on
    00095    *  operator overloading in this class.
    00096    *
    00097    *  @if maint
    00098    *  All the functions are op overloads except for _M_set_node.
    00099    *  @endif
    00100   */
    00101   template<typename _Tp, typename _Ref, typename _Ptr>
    00102     struct _Deque_iterator
    00103     {
    00104       typedef _Deque_iterator<_Tp, _Tp&, _Tp*>             iterator;
    00105       typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
    00106
    00107       static size_t _S_buffer_size()
    00108       { return __deque_buf_size(sizeof(_Tp)); }
    00109
    00110       typedef std::random_access_iterator_tag iterator_category;
    00111       typedef _Tp                             value_type;
    00112       typedef _Ptr                            pointer;
    00113       typedef _Ref                            reference;
    00114       typedef size_t                          size_type;
    00115       typedef ptrdiff_t                       difference_type;
    00116       typedef _Tp**                           _Map_pointer;
    00117       typedef _Deque_iterator                 _Self;
    00118
    00119       _Tp* _M_cur;
    00120       _Tp* _M_first;
    00121       _Tp* _M_last;
    00122       _Map_pointer _M_node;
    00123
    00124       _Deque_iterator(_Tp* __x, _Map_pointer __y)
    00125       : _M_cur(__x), _M_first(*__y),
    00126         _M_last(*__y + _S_buffer_size()), _M_node(__y) {}
    00127
    00128       _Deque_iterator() : _M_cur(0), _M_first(0), _M_last(0), _M_node(0) {}
    00129
    00130       _Deque_iterator(const iterator& __x)
    00131       : _M_cur(__x._M_cur), _M_first(__x._M_first),
    00132         _M_last(__x._M_last), _M_node(__x._M_node) {}
    00133
    00134       reference
    00135       operator*() const
    00136       { return *_M_cur; }
    00137
    00138       pointer
    00139       operator->() const
    00140       { return _M_cur; }
    00141
    00142       _Self&
    00143       operator++()
    00144       {
    00145     ++_M_cur;
    00146     if (_M_cur == _M_last)
    00147       {
    00148         _M_set_node(_M_node + 1);
    00149         _M_cur = _M_first;
    00150       }
    00151     return *this;
    00152       }
    00153
    00154       _Self
    00155       operator++(int)
    00156       {
    00157     _Self __tmp = *this;
    00158     ++*this;
    00159     return __tmp;
    00160       }
    00161
    00162       _Self&
    00163       operator--()
    00164       {
    00165     if (_M_cur == _M_first)
    00166       {
    00167         _M_set_node(_M_node - 1);
    00168         _M_cur = _M_last;
    00169       }
    00170     --_M_cur;
    00171     return *this;
    00172       }
    00173
    00174       _Self
    00175       operator--(int)
    00176       {
    00177     _Self __tmp = *this;
    00178     --*this;
    00179     return __tmp;
    00180       }
    00181
    00182       _Self&
    00183       operator+=(difference_type __n)
    00184       {
    00185     const difference_type __offset = __n + (_M_cur - _M_first);
    00186     if (__offset >= 0 && __offset < difference_type(_S_buffer_size()))
    00187       _M_cur += __n;
    00188     else
    00189       {
    00190         const difference_type __node_offset =
    00191           __offset > 0 ? __offset / difference_type(_S_buffer_size())
    00192                        : -difference_type((-__offset - 1)
    00193                           / _S_buffer_size()) - 1;
    00194         _M_set_node(_M_node + __node_offset);
    00195         _M_cur = _M_first + (__offset - __node_offset
    00196                  * difference_type(_S_buffer_size()));
    00197       }
    00198     return *this;
    00199       }
    00200
    00201       _Self
    00202       operator+(difference_type __n) const
    00203       {
    00204     _Self __tmp = *this;
    00205     return __tmp += __n;
    00206       }
    00207
    00208       _Self&
    00209       operator-=(difference_type __n)
    00210       { return *this += -__n; }
    00211
    00212       _Self
    00213       operator-(difference_type __n) const
    00214       {
    00215     _Self __tmp = *this;
    00216     return __tmp -= __n;
    00217       }
    00218
    00219       reference
    00220       operator[](difference_type __n) const
    00221       { return *(*this + __n); }
    00222
    00223       /** @if maint
    00224        *  Prepares to traverse new_node.  Sets everything except
    00225        *  _M_cur, which should therefore be set by the caller
    00226        *  immediately afterwards, based on _M_first and _M_last.
    00227        *  @endif
    00228        */
    00229       void
    00230       _M_set_node(_Map_pointer __new_node)
    00231       {
    00232     _M_node = __new_node;
    00233     _M_first = *__new_node;
    00234     _M_last = _M_first + difference_type(_S_buffer_size());
    00235       }
    00236     };
    00237
    00238   // Note: we also provide overloads whose operands are of the same type in
    00239   // order to avoid ambiguous overload resolution when std::rel_ops operators
    00240   // are in scope (for additional details, see libstdc++/3628)
    00241   template<typename _Tp, typename _Ref, typename _Ptr>
    00242     inline bool
    00243     operator==(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
    00244            const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
    00245     { return __x._M_cur == __y._M_cur; }
    00246
    00247   template<typename _Tp, typename _RefL, typename _PtrL,
    00248        typename _RefR, typename _PtrR>
    00249     inline bool
    00250     operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
    00251            const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
    00252     { return __x._M_cur == __y._M_cur; }
    00253
    00254   template<typename _Tp, typename _Ref, typename _Ptr>
    00255     inline bool
    00256     operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
    00257            const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
    00258     { return !(__x == __y); }
    00259
    00260   template<typename _Tp, typename _RefL, typename _PtrL,
    00261        typename _RefR, typename _PtrR>
    00262     inline bool
    00263     operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
    00264            const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
    00265     { return !(__x == __y); }
    00266
    00267   template<typename _Tp, typename _Ref, typename _Ptr>
    00268     inline bool
    00269     operator<(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
    00270           const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
    00271     { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur)
    00272                                           : (__x._M_node < __y._M_node); }
    00273
    00274   template<typename _Tp, typename _RefL, typename _PtrL,
    00275        typename _RefR, typename _PtrR>
    00276     inline bool
    00277     operator<(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
    00278           const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
    00279     { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur)
    00280                                       : (__x._M_node < __y._M_node); }
    00281
    00282   template<typename _Tp, typename _Ref, typename _Ptr>
    00283     inline bool
    00284     operator>(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
    00285           const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
    00286     { return __y < __x; }
    00287
    00288   template<typename _Tp, typename _RefL, typename _PtrL,
    00289        typename _RefR, typename _PtrR>
    00290     inline bool
    00291     operator>(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
    00292           const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
    00293     { return __y < __x; }
    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     { return !(__y < __x); }
    00300
    00301   template<typename _Tp, typename _RefL, typename _PtrL,
    00302        typename _RefR, typename _PtrR>
    00303     inline bool
    00304     operator<=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
    00305            const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
    00306     { return !(__y < __x); }
    00307
    00308   template<typename _Tp, typename _Ref, typename _Ptr>
    00309     inline bool
    00310     operator>=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
    00311            const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
    00312     { return !(__x < __y); }
    00313
    00314   template<typename _Tp, typename _RefL, typename _PtrL,
    00315        typename _RefR, typename _PtrR>
    00316     inline bool
    00317     operator>=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
    00318            const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
    00319     { return !(__x < __y); }
    00320
    00321   // _GLIBCXX_RESOLVE_LIB_DEFECTS
    00322   // According to the resolution of DR179 not only the various comparison
    00323   // operators but also operator- must accept mixed iterator/const_iterator
    00324   // parameters.
    00325   template<typename _Tp, typename _Ref, typename _Ptr>
    00326     inline typename _Deque_iterator<_Tp, _Ref, _Ptr>::difference_type
    00327     operator-(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
    00328           const _Deque_iterator<_Tp, _Ref, _Ptr>& __y)
    00329     {
    00330       return typename _Deque_iterator<_Tp, _Ref, _Ptr>::difference_type
    00331     (_Deque_iterator<_Tp, _Ref, _Ptr>::_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 _RefL, typename _PtrL,
    00337        typename _RefR, typename _PtrR>
    00338     inline typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
    00339     operator-(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
    00340           const _Deque_iterator<_Tp, _RefR, _PtrR>& __y)
    00341     {
    00342       return typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
    00343     (_Deque_iterator<_Tp, _RefL, _PtrL>::_S_buffer_size())
    00344     * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first)
    00345     + (__y._M_last - __y._M_cur);
    00346     }
    00347
    00348   template<typename _Tp, typename _Ref, typename _Ptr>
    00349     inline _Deque_iterator<_Tp, _Ref, _Ptr>
    00350     operator+(ptrdiff_t __n, const _Deque_iterator<_Tp, _Ref, _Ptr>& __x)
    00351     { return __x + __n; }
    00352
    00353   template<typename _Tp>
    00354     void
    00355     fill(const _Deque_iterator<_Tp, _Tp&, _Tp*>& __first,
    00356      const _Deque_iterator<_Tp, _Tp&, _Tp*>& __last, const _Tp& __value);
    00357
    00358   /**
    00359    *  @if maint
    00360    *  Deque base class.  This class provides the unified face for %deque's
    00361    *  allocation.  This class's constructor and destructor allocate and
    00362    *  deallocate (but do not initialize) storage.  This makes %exception
    00363    *  safety easier.
    00364    *
    00365    *  Nothing in this class ever constructs or destroys an actual Tp element.
    00366    *  (Deque handles that itself.)  Only/All memory management is performed
    00367    *  here.
    00368    *  @endif
    00369   */
    00370   template<typename _Tp, typename _Alloc>
    00371     class _Deque_base
    00372     {
    00373     public:
    00374       typedef _Alloc                  allocator_type;
    00375
    00376       allocator_type
    00377       get_allocator() const
    00378       { return allocator_type(_M_get_Tp_allocator()); }
    00379
    00380       typedef _Deque_iterator<_Tp, _Tp&, _Tp*>             iterator;
    00381       typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
    00382
    00383       _Deque_base(const allocator_type& __a, size_t __num_elements)
    00384       : _M_impl(__a)
    00385       { _M_initialize_map(__num_elements); }
    00386
    00387       _Deque_base(const allocator_type& __a)
    00388       : _M_impl(__a)
    00389       { }
    00390
    00391       ~_Deque_base();
    00392
    00393     protected:
    00394       //This struct encapsulates the implementation of the std::deque
    00395       //standard container and at the same time makes use of the EBO
    00396       //for empty allocators.
    00397       typedef typename _Alloc::template rebind<_Tp*>::other _Map_alloc_type;
    00398
    00399       typedef typename _Alloc::template rebind<_Tp>::other  _Tp_alloc_type;
    00400
    00401       struct _Deque_impl
    00402       : public _Tp_alloc_type
    00403       {
    00404     _Tp** _M_map;
    00405     size_t _M_map_size;
    00406     iterator _M_start;
    00407     iterator _M_finish;
    00408
    00409     _Deque_impl(const _Tp_alloc_type& __a)
    00410     : _Tp_alloc_type(__a), _M_map(0), _M_map_size(0),
    00411       _M_start(), _M_finish()
    00412     { }
    00413       };
    00414
    00415       _Tp_alloc_type&
    00416       _M_get_Tp_allocator()
    00417       { return *static_cast<_Tp_alloc_type*>(&this->_M_impl); }
    00418
    00419       const _Tp_alloc_type&
    00420       _M_get_Tp_allocator() const
    00421       { return *static_cast<const _Tp_alloc_type*>(&this->_M_impl); }
    00422
    00423       _Map_alloc_type
    00424       _M_get_map_allocator() const
    00425       { return _Map_alloc_type(_M_get_Tp_allocator()); }
    00426
    00427       _Tp*
    00428       _M_allocate_node()
    00429       {
    00430     return _M_impl._Tp_alloc_type::allocate(__deque_buf_size(sizeof(_Tp)));
    00431       }
    00432
    00433       void
    00434       _M_deallocate_node(_Tp* __p)
    00435       {
    00436     _M_impl._Tp_alloc_type::deallocate(__p, __deque_buf_size(sizeof(_Tp)));
    00437       }
    00438
    00439       _Tp**
    00440       _M_allocate_map(size_t __n)
    00441       { return _M_get_map_allocator().allocate(__n); }
    00442
    00443       void
    00444       _M_deallocate_map(_Tp** __p, size_t __n)
    00445       { _M_get_map_allocator().deallocate(__p, __n); }
    00446
    00447     protected:
    00448       void _M_initialize_map(size_t);
    00449       void _M_create_nodes(_Tp** __nstart, _Tp** __nfinish);
    00450       void _M_destroy_nodes(_Tp** __nstart, _Tp** __nfinish);
    00451       enum { _S_initial_map_size = 8 };
    00452
    00453       _Deque_impl _M_impl;
    00454     };
    00455
    00456   template<typename _Tp, typename _Alloc>
    00457     _Deque_base<_Tp, _Alloc>::
    00458     ~_Deque_base()
    00459     {
    00460       if (this->_M_impl._M_map)
    00461     {
    00462       _M_destroy_nodes(this->_M_impl._M_start._M_node,
    00463                this->_M_impl._M_finish._M_node + 1);
    00464       _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
    00465     }
    00466     }
    00467
    00468   /**
    00469    *  @if maint
    00470    *  @brief Layout storage.
    00471    *  @param  num_elements  The count of T's for which to allocate space
    00472    *                        at first.
    00473    *  @return   Nothing.
    00474    *
    00475    *  The initial underlying memory layout is a bit complicated...
    00476    *  @endif
    00477   */
    00478   template<typename _Tp, typename _Alloc>
    00479     void
    00480     _Deque_base<_Tp, _Alloc>::
    00481     _M_initialize_map(size_t __num_elements)
    00482     {
    00483       const size_t __num_nodes = (__num_elements/ __deque_buf_size(sizeof(_Tp))
    00484                   + 1);
    00485
    00486       this->_M_impl._M_map_size = std::max((size_t) _S_initial_map_size,
    00487                        size_t(__num_nodes + 2));
    00488       this->_M_impl._M_map = _M_allocate_map(this->_M_impl._M_map_size);
    00489
    00490       // For "small" maps (needing less than _M_map_size nodes), allocation
    00491       // starts in the middle elements and grows outwards.  So nstart may be
    00492       // the beginning of _M_map, but for small maps it may be as far in as
    00493       // _M_map+3.
    00494
    00495       _Tp** __nstart = (this->_M_impl._M_map
    00496             + (this->_M_impl._M_map_size - __num_nodes) / 2);
    00497       _Tp** __nfinish = __nstart + __num_nodes;
    00498
    00499       try
    00500     { _M_create_nodes(__nstart, __nfinish); }
    00501       catch(...)
    00502     {
    00503       _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
    00504       this->_M_impl._M_map = 0;
    00505       this->_M_impl._M_map_size = 0;
    00506       __throw_exception_again;
    00507     }
    00508
    00509       this->_M_impl._M_start._M_set_node(__nstart);
    00510       this->_M_impl._M_finish._M_set_node(__nfinish - 1);
    00511       this->_M_impl._M_start._M_cur = _M_impl._M_start._M_first;
    00512       this->_M_impl._M_finish._M_cur = (this->_M_impl._M_finish._M_first
    00513                     + __num_elements
    00514                     % __deque_buf_size(sizeof(_Tp)));
    00515     }
    00516
    00517   template<typename _Tp, typename _Alloc>
    00518     void
    00519     _Deque_base<_Tp, _Alloc>::
    00520     _M_create_nodes(_Tp** __nstart, _Tp** __nfinish)
    00521     {
    00522       _Tp** __cur;
    00523       try
    00524     {
    00525       for (__cur = __nstart; __cur < __nfinish; ++__cur)
    00526         *__cur = this->_M_allocate_node();
    00527     }
    00528       catch(...)
    00529     {
    00530       _M_destroy_nodes(__nstart, __cur);
    00531       __throw_exception_again;
    00532     }
    00533     }
    00534
    00535   template<typename _Tp, typename _Alloc>
    00536     void
    00537     _Deque_base<_Tp, _Alloc>::
    00538     _M_destroy_nodes(_Tp** __nstart, _Tp** __nfinish)
    00539     {
    00540       for (_Tp** __n = __nstart; __n < __nfinish; ++__n)
    00541     _M_deallocate_node(*__n);
    00542     }
    00543
    00544   /**
    00545    *  @brief  A standard container using fixed-size memory allocation and
    00546    *  constant-time manipulation of elements at either end.
    00547    *
    00548    *  @ingroup Containers
    00549    *  @ingroup Sequences
    00550    *
    00551    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
    00552    *  <a href="tables.html#66">reversible container</a>, and a
    00553    *  <a href="tables.html#67">sequence</a>, including the
    00554    *  <a href="tables.html#68">optional sequence requirements</a>.
    00555    *
    00556    *  In previous HP/SGI versions of deque, there was an extra template
    00557    *  parameter so users could control the node size.  This extension turned
    00558    *  out to violate the C++ standard (it can be detected using template
    00559    *  template parameters), and it was removed.
    00560    *
    00561    *  @if maint
    00562    *  Here's how a deque<Tp> manages memory.  Each deque has 4 members:
    00563    *
    00564    *  - Tp**        _M_map
    00565    *  - size_t      _M_map_size
    00566    *  - iterator    _M_start, _M_finish
    00567    *
    00568    *  map_size is at least 8.  %map is an array of map_size
    00569    *  pointers-to-"nodes".  (The name %map has nothing to do with the
    00570    *  std::map class, and "nodes" should not be confused with
    00571    *  std::list's usage of "node".)
    00572    *
    00573    *  A "node" has no specific type name as such, but it is referred
    00574    *  to as "node" in this file.  It is a simple array-of-Tp.  If Tp
    00575    *  is very large, there will be one Tp element per node (i.e., an
    00576    *  "array" of one).  For non-huge Tp's, node size is inversely
    00577    *  related to Tp size: the larger the Tp, the fewer Tp's will fit
    00578    *  in a node.  The goal here is to keep the total size of a node
    00579    *  relatively small and constant over different Tp's, to improve
    00580    *  allocator efficiency.
    00581    *
    00582    *  Not every pointer in the %map array will point to a node.  If
    00583    *  the initial number of elements in the deque is small, the
    00584    *  /middle/ %map pointers will be valid, and the ones at the edges
    00585    *  will be unused.  This same situation will arise as the %map
    00586    *  grows: available %map pointers, if any, will be on the ends.  As
    00587    *  new nodes are created, only a subset of the %map's pointers need
    00588    *  to be copied "outward".
    00589    *
    00590    *  Class invariants:
    00591    * - For any nonsingular iterator i:
    00592    *    - i.node points to a member of the %map array.  (Yes, you read that
    00593    *      correctly:  i.node does not actually point to a node.)  The member of
    00594    *      the %map array is what actually points to the node.
    00595    *    - i.first == *(i.node)    (This points to the node (first Tp element).)
    00596    *    - i.last  == i.first + node_size
    00597    *    - i.cur is a pointer in the range [i.first, i.last).  NOTE:
    00598    *      the implication of this is that i.cur is always a dereferenceable
    00599    *      pointer, even if i is a past-the-end iterator.
    00600    * - Start and Finish are always nonsingular iterators.  NOTE: this
    00601    * means that an empty deque must have one node, a deque with <N
    00602    * elements (where N is the node buffer size) must have one node, a
    00603    * deque with N through (2N-1) elements must have two nodes, etc.
    00604    * - For every node other than start.node and finish.node, every
    00605    * element in the node is an initialized object.  If start.node ==
    00606    * finish.node, then [start.cur, finish.cur) are initialized
    00607    * objects, and the elements outside that range are uninitialized
    00608    * storage.  Otherwise, [start.cur, start.last) and [finish.first,
    00609    * finish.cur) are initialized objects, and [start.first, start.cur)
    00610    * and [finish.cur, finish.last) are uninitialized storage.
    00611    * - [%map, %map + map_size) is a valid, non-empty range.
    00612    * - [start.node, finish.node] is a valid range contained within
    00613    *   [%map, %map + map_size).
    00614    * - A pointer in the range [%map, %map + map_size) points to an allocated
    00615    *   node if and only if the pointer is in the range
    00616    *   [start.node, finish.node].
    00617    *
    00618    *  Here's the magic:  nothing in deque is "aware" of the discontiguous
    00619    *  storage!
    00620    *
    00621    *  The memory setup and layout occurs in the parent, _Base, and the iterator
    00622    *  class is entirely responsible for "leaping" from one node to the next.
    00623    *  All the implementation routines for deque itself work only through the
    00624    *  start and finish iterators.  This keeps the routines simple and sane,
    00625    *  and we can use other standard algorithms as well.
    00626    *  @endif
    00627   */
    00628   template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
    00629     class deque : protected _Deque_base<_Tp, _Alloc>
    00630     {
    00631       // concept requirements
    00632       typedef typename _Alloc::value_type        _Alloc_value_type;
    00633       __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
    00634       __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept)
    00635
    00636       typedef _Deque_base<_Tp, _Alloc>           _Base;
    00637       typedef typename _Base::_Tp_alloc_type     _Tp_alloc_type;
    00638
    00639     public:
    00640       typedef _Tp                                        value_type;
    00641       typedef typename _Tp_alloc_type::pointer           pointer;
    00642       typedef typename _Tp_alloc_type::const_pointer     const_pointer;
    00643       typedef typename _Tp_alloc_type::reference         reference;
    00644       typedef typename _Tp_alloc_type::const_reference   const_reference;
    00645       typedef typename _Base::iterator                   iterator;
    00646       typedef typename _Base::const_iterator             const_iterator;
    00647       typedef std::reverse_iterator<const_iterator>      const_reverse_iterator;
    00648       typedef std::reverse_iterator<iterator>            reverse_iterator;
    00649       typedef size_t                             size_type;
    00650       typedef ptrdiff_t                          difference_type;
    00651       typedef _Alloc                             allocator_type;
    00652
    00653     protected:
    00654       typedef pointer*                           _Map_pointer;
    00655
    00656       static size_t _S_buffer_size()
    00657       { return __deque_buf_size(sizeof(_Tp)); }
    00658
    00659       // Functions controlling memory layout, and nothing else.
    00660       using _Base::_M_initialize_map;
    00661       using _Base::_M_create_nodes;
    00662       using _Base::_M_destroy_nodes;
    00663       using _Base::_M_allocate_node;
    00664       using _Base::_M_deallocate_node;
    00665       using _Base::_M_allocate_map;
    00666       using _Base::_M_deallocate_map;
    00667       using _Base::_M_get_Tp_allocator;
    00668
    00669       /** @if maint
    00670        *  A total of four data members accumulated down the heirarchy.
    00671        *  May be accessed via _M_impl.*
    00672        *  @endif
    00673        */
    00674       using _Base::_M_impl;
    00675
    00676     public:
    00677       // [23.2.1.1] construct/copy/destroy
    00678       // (assign() and get_allocator() are also listed in this section)
    00679       /**
    00680        *  @brief  Default constructor creates no elements.
    00681        */
    00682       explicit
    00683       deque(const allocator_type& __a = allocator_type())
    00684       : _Base(__a, 0) {}
    00685
    00686       /**
    00687        *  @brief  Create a %deque with copies of an exemplar element.
    00688        *  @param  n  The number of elements to initially create.
    00689        *  @param  value  An element to copy.
    00690        *
    00691        *  This constructor fills the %deque with @a n copies of @a value.
    00692        */
    00693       explicit
    00694       deque(size_type __n, const value_type& __value = value_type(),
    00695         const allocator_type& __a = allocator_type())
    00696       : _Base(__a, __n)
    00697       { _M_fill_initialize(__value); }
    00698
    00699       /**
    00700        *  @brief  %Deque copy constructor.
    00701        *  @param  x  A %deque of identical element and allocator types.
    00702        *
    00703        *  The newly-created %deque uses a copy of the allocation object used
    00704        *  by @a x.
    00705        */
    00706       deque(const deque& __x)
    00707       : _Base(__x._M_get_Tp_allocator(), __x.size())
    00708       { std::__uninitialized_copy_a(__x.begin(), __x.end(),
    00709                     this->_M_impl._M_start,
    00710                     _M_get_Tp_allocator()); }
    00711
    00712       /**
    00713        *  @brief  Builds a %deque from a range.
    00714        *  @param  first  An input iterator.
    00715        *  @param  last  An input iterator.
    00716        *
    00717        *  Create a %deque consisting of copies of the elements from [first,
    00718        *  last).
    00719        *
    00720        *  If the iterators are forward, bidirectional, or random-access, then
    00721        *  this will call the elements' copy constructor N times (where N is
    00722        *  distance(first,last)) and do no memory reallocation.  But if only
    00723        *  input iterators are used, then this will do at most 2N calls to the
    00724        *  copy constructor, and logN memory reallocations.
    00725        */
    00726       template<typename _InputIterator>
    00727         deque(_InputIterator __first, _InputIterator __last,
    00728           const allocator_type& __a = allocator_type())
    00729     : _Base(__a)
    00730         {
    00731       // Check whether it's an integral type.  If so, it's not an iterator.
    00732       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
    00733       _M_initialize_dispatch(__first, __last, _Integral());
    00734     }
    00735
    00736       /**
    00737        *  The dtor only erases the elements, and note that if the elements
    00738        *  themselves are pointers, the pointed-to memory is not touched in any
    00739        *  way.  Managing the pointer is the user's responsibilty.
    00740        */
    00741       ~deque()
    00742       { _M_destroy_data(begin(), end(), _M_get_Tp_allocator()); }
    00743
    00744       /**
    00745        *  @brief  %Deque assignment operator.
    00746        *  @param  x  A %deque of identical element and allocator types.
    00747        *
    00748        *  All the elements of @a x are copied, but unlike the copy constructor,
    00749        *  the allocator object is not copied.
    00750        */
    00751       deque&
    00752       operator=(const deque& __x);
    00753
    00754       /**
    00755        *  @brief  Assigns a given value to a %deque.
    00756        *  @param  n  Number of elements to be assigned.
    00757        *  @param  val  Value to be assigned.
    00758        *
    00759        *  This function fills a %deque with @a n copies of the given
    00760        *  value.  Note that the assignment completely changes the
    00761        *  %deque and that the resulting %deque's size is the same as
    00762        *  the number of elements assigned.  Old data may be lost.
    00763        */
    00764       void
    00765       assign(size_type __n, const value_type& __val)
    00766       { _M_fill_assign(__n, __val); }
    00767
    00768       /**
    00769        *  @brief  Assigns a range to a %deque.
    00770        *  @param  first  An input iterator.
    00771        *  @param  last   An input iterator.
    00772        *
    00773        *  This function fills a %deque with copies of the elements in the
    00774        *  range [first,last).
    00775        *
    00776        *  Note that the assignment completely changes the %deque and that the
    00777        *  resulting %deque's size is the same as the number of elements
    00778        *  assigned.  Old data may be lost.
    00779        */
    00780       template<typename _InputIterator>
    00781         void
    00782         assign(_InputIterator __first, _InputIterator __last)
    00783         {
    00784       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
    00785       _M_assign_dispatch(__first, __last, _Integral());
    00786     }
    00787
    00788       /// Get a copy of the memory allocation object.
    00789       allocator_type
    00790       get_allocator() const
    00791       { return _Base::get_allocator(); }
    00792
    00793       // iterators
    00794       /**
    00795        *  Returns a read/write iterator that points to the first element in the
    00796        *  %deque.  Iteration is done in ordinary element order.
    00797        */
    00798       iterator
    00799       begin()
    00800       { return this->_M_impl._M_start; }
    00801
    00802       /**
    00803        *  Returns a read-only (constant) iterator that points to the first
    00804        *  element in the %deque.  Iteration is done in ordinary element order.
    00805        */
    00806       const_iterator
    00807       begin() const
    00808       { return this->_M_impl._M_start; }
    00809
    00810       /**
    00811        *  Returns a read/write iterator that points one past the last
    00812        *  element in the %deque.  Iteration is done in ordinary
    00813        *  element order.
    00814        */
    00815       iterator
    00816       end()
    00817       { return this->_M_impl._M_finish; }
    00818
    00819       /**
    00820        *  Returns a read-only (constant) iterator that points one past
    00821        *  the last element in the %deque.  Iteration is done in
    00822        *  ordinary element order.
    00823        */
    00824       const_iterator
    00825       end() const
    00826       { return this->_M_impl._M_finish; }
    00827
    00828       /**
    00829        *  Returns a read/write reverse iterator that points to the
    00830        *  last element in the %deque.  Iteration is done in reverse
    00831        *  element order.
    00832        */
    00833       reverse_iterator
    00834       rbegin()
    00835       { return reverse_iterator(this->_M_impl._M_finish); }
    00836
    00837       /**
    00838        *  Returns a read-only (constant) reverse iterator that points
    00839        *  to the last element in the %deque.  Iteration is done in
    00840        *  reverse element order.
    00841        */
    00842       const_reverse_iterator
    00843       rbegin() const
    00844       { return const_reverse_iterator(this->_M_impl._M_finish); }
    00845
    00846       /**
    00847        *  Returns a read/write reverse iterator that points to one
    00848        *  before the first element in the %deque.  Iteration is done
    00849        *  in reverse element order.
    00850        */
    00851       reverse_iterator
    00852       rend()
    00853       { return reverse_iterator(this->_M_impl._M_start); }
    00854
    00855       /**
    00856        *  Returns a read-only (constant) reverse iterator that points
    00857        *  to one before the first element in the %deque.  Iteration is
    00858        *  done in reverse element order.
    00859        */
    00860       const_reverse_iterator
    00861       rend() const
    00862       { return const_reverse_iterator(this->_M_impl._M_start); }
    00863
    00864       // [23.2.1.2] capacity
    00865       /**  Returns the number of elements in the %deque.  */
    00866       size_type
    00867       size() const
    00868       { return this->_M_impl._M_finish - this->_M_impl._M_start; }
    00869
    00870       /**  Returns the size() of the largest possible %deque.  */
    00871       size_type
    00872       max_size() const
    00873       { return _M_get_Tp_allocator().max_size(); }
    00874
    00875       /**
    00876        *  @brief  Resizes the %deque to the specified number of elements.
    00877        *  @param  new_size  Number of elements the %deque should contain.
    00878        *  @param  x  Data with which new elements should be populated.
    00879        *
    00880        *  This function will %resize the %deque to the specified
    00881        *  number of elements.  If the number is smaller than the
    00882        *  %deque's current size the %deque is truncated, otherwise the
    00883        *  %deque is extended and new elements are populated with given
    00884        *  data.
    00885        */
    00886       void
    00887       resize(size_type __new_size, value_type __x = value_type())
    00888       {
    00889     const size_type __len = size();
    00890     if (__new_size < __len)
    00891       _M_erase_at_end(this->_M_impl._M_start + difference_type(__new_size));
    00892     else
    00893       insert(this->_M_impl._M_finish, __new_size - __len, __x);
    00894       }
    00895
    00896       /**
    00897        *  Returns true if the %deque is empty.  (Thus begin() would
    00898        *  equal end().)
    00899        */
    00900       bool
    00901       empty() const
    00902       { return this->_M_impl._M_finish == this->_M_impl._M_start; }
    00903
    00904       // element access
    00905       /**
    00906        *  @brief Subscript access to the data contained in the %deque.
    00907        *  @param n The index of the element for which data should be
    00908        *  accessed.
    00909        *  @return  Read/write reference to data.
    00910        *
    00911        *  This operator allows for easy, array-style, data access.
    00912        *  Note that data access with this operator is unchecked and
    00913        *  out_of_range lookups are not defined. (For checked lookups
    00914        *  see at().)
    00915        */
    00916       reference
    00917       operator[](size_type __n)
    00918       { return this->_M_impl._M_start[difference_type(__n)]; }
    00919
    00920       /**
    00921        *  @brief Subscript access to the data contained in the %deque.
    00922        *  @param n The index of the element for which data should be
    00923        *  accessed.
    00924        *  @return  Read-only (constant) reference to data.
    00925        *
    00926        *  This operator allows for easy, array-style, data access.
    00927        *  Note that data access with this operator is unchecked and
    00928        *  out_of_range lookups are not defined. (For checked lookups
    00929        *  see at().)
    00930        */
    00931       const_reference
    00932       operator[](size_type __n) const
    00933       { return this->_M_impl._M_start[difference_type(__n)]; }
    00934
    00935     protected:
    00936       /// @if maint Safety check used only from at().  @endif
    00937       void
    00938       _M_range_check(size_type __n) const
    00939       {
    00940     if (__n >= this->size())
    00941       __throw_out_of_range(__N("deque::_M_range_check"));
    00942       }
    00943
    00944     public:
    00945       /**
    00946        *  @brief  Provides access to the data contained in the %deque.
    00947        *  @param n The index of the element for which data should be
    00948        *  accessed.
    00949        *  @return  Read/write reference to data.
    00950        *  @throw  std::out_of_range  If @a n is an invalid index.
    00951        *
    00952        *  This function provides for safer data access.  The parameter
    00953        *  is first checked that it is in the range of the deque.  The
    00954        *  function throws out_of_range if the check fails.
    00955        */
    00956       reference
    00957       at(size_type __n)
    00958       {
    00959     _M_range_check(__n);
    00960     return (*this)[__n];
    00961       }
    00962
    00963       /**
    00964        *  @brief  Provides access to the data contained in the %deque.
    00965        *  @param n The index of the element for which data should be
    00966        *  accessed.
    00967        *  @return  Read-only (constant) reference to data.
    00968        *  @throw  std::out_of_range  If @a n is an invalid index.
    00969        *
    00970        *  This function provides for safer data access.  The parameter is first
    00971        *  checked that it is in the range of the deque.  The function throws
    00972        *  out_of_range if the check fails.
    00973        */
    00974       const_reference
    00975       at(size_type __n) const
    00976       {
    00977     _M_range_check(__n);
    00978     return (*this)[__n];
    00979       }
    00980
    00981       /**
    00982        *  Returns a read/write reference to the data at the first
    00983        *  element of the %deque.
    00984        */
    00985       reference
    00986       front()
    00987       { return *begin(); }
    00988
    00989       /**
    00990        *  Returns a read-only (constant) reference to the data at the first
    00991        *  element of the %deque.
    00992        */
    00993       const_reference
    00994       front() const
    00995       { return *begin(); }
    00996
    00997       /**
    00998        *  Returns a read/write reference to the data at the last element of the
    00999        *  %deque.
    01000        */
    01001       reference
    01002       back()
    01003       {
    01004     iterator __tmp = end();
    01005     --__tmp;
    01006     return *__tmp;
    01007       }
    01008
    01009       /**
    01010        *  Returns a read-only (constant) reference to the data at the last
    01011        *  element of the %deque.
    01012        */
    01013       const_reference
    01014       back() const
    01015       {
    01016     const_iterator __tmp = end();
    01017     --__tmp;
    01018     return *__tmp;
    01019       }
    01020
    01021       // [23.2.1.2] modifiers
    01022       /**
    01023        *  @brief  Add data to the front of the %deque.
    01024        *  @param  x  Data to be added.
    01025        *
    01026        *  This is a typical stack operation.  The function creates an
    01027        *  element at the front of the %deque and assigns the given
    01028        *  data to it.  Due to the nature of a %deque this operation
    01029        *  can be done in constant time.
    01030        */
    01031       void
    01032       push_front(const value_type& __x)
    01033       {
    01034     if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_first)
    01035       {
    01036         this->_M_impl.construct(this->_M_impl._M_start._M_cur - 1, __x);
    01037         --this->_M_impl._M_start._M_cur;
    01038       }
    01039     else
    01040       _M_push_front_aux(__x);
    01041       }
    01042
    01043       /**
    01044        *  @brief  Add data to the end of the %deque.
    01045        *  @param  x  Data to be added.
    01046        *
    01047        *  This is a typical stack operation.  The function creates an
    01048        *  element at the end of the %deque and assigns the given data
    01049        *  to it.  Due to the nature of a %deque this operation can be
    01050        *  done in constant time.
    01051        */
    01052       void
    01053       push_back(const value_type& __x)
    01054       {
    01055     if (this->_M_impl._M_finish._M_cur
    01056         != this->_M_impl._M_finish._M_last - 1)
    01057       {
    01058         this->_M_impl.construct(this->_M_impl._M_finish._M_cur, __x);
    01059         ++this->_M_impl._M_finish._M_cur;
    01060       }
    01061     else
    01062       _M_push_back_aux(__x);
    01063       }
    01064
    01065       /**
    01066        *  @brief  Removes first element.
    01067        *
    01068        *  This is a typical stack operation.  It shrinks the %deque by one.
    01069        *
    01070        *  Note that no data is returned, and if the first element's data is
    01071        *  needed, it should be retrieved before pop_front() is called.
    01072        */
    01073       void
    01074       pop_front()
    01075       {
    01076     if (this->_M_impl._M_start._M_cur
    01077         != this->_M_impl._M_start._M_last - 1)
    01078       {
    01079         this->_M_impl.destroy(this->_M_impl._M_start._M_cur);
    01080         ++this->_M_impl._M_start._M_cur;
    01081       }
    01082     else
    01083       _M_pop_front_aux();
    01084       }
    01085
    01086       /**
    01087        *  @brief  Removes last element.
    01088        *
    01089        *  This is a typical stack operation.  It shrinks the %deque by one.
    01090        *
    01091        *  Note that no data is returned, and if the last element's data is
    01092        *  needed, it should be retrieved before pop_back() is called.
    01093        */
    01094       void
    01095       pop_back()
    01096       {
    01097     if (this->_M_impl._M_finish._M_cur
    01098         != this->_M_impl._M_finish._M_first)
    01099       {
    01100         --this->_M_impl._M_finish._M_cur;
    01101         this->_M_impl.destroy(this->_M_impl._M_finish._M_cur);
    01102       }
    01103     else
    01104       _M_pop_back_aux();
    01105       }
    01106
    01107       /**
    01108        *  @brief  Inserts given value into %deque before specified iterator.
    01109        *  @param  position  An iterator into the %deque.
    01110        *  @param  x  Data to be inserted.
    01111        *  @return  An iterator that points to the inserted data.
    01112        *
    01113        *  This function will insert a copy of the given value before the
    01114        *  specified location.
    01115        */
    01116       iterator
    01117       insert(iterator __position, const value_type& __x);
    01118
    01119       /**
    01120        *  @brief  Inserts a number of copies of given data into the %deque.
    01121        *  @param  position  An iterator into the %deque.
    01122        *  @param  n  Number of elements to be inserted.
    01123        *  @param  x  Data to be inserted.
    01124        *
    01125        *  This function will insert a specified number of copies of the given
    01126        *  data before the location specified by @a position.
    01127        */
    01128       void
    01129       insert(iterator __position, size_type __n, const value_type& __x)
    01130       { _M_fill_insert(__position, __n, __x); }
    01131
    01132       /**
    01133        *  @brief  Inserts a range into the %deque.
    01134        *  @param  position  An iterator into the %deque.
    01135        *  @param  first  An input iterator.
    01136        *  @param  last   An input iterator.
    01137        *
    01138        *  This function will insert copies of the data in the range
    01139        *  [first,last) into the %deque before the location specified
    01140        *  by @a pos.  This is known as "range insert."
    01141        */
    01142       template<typename _InputIterator>
    01143         void
    01144         insert(iterator __position, _InputIterator __first,
    01145            _InputIterator __last)
    01146         {
    01147       // Check whether it's an integral type.  If so, it's not an iterator.
    01148       typedef typename std::__is_integer<_InputIterator>::__type _Integral;
    01149       _M_insert_dispatch(__position, __first, __last, _Integral());
    01150     }
    01151
    01152       /**
    01153        *  @brief  Remove element at given position.
    01154        *  @param  position  Iterator pointing to element to be erased.
    01155        *  @return  An iterator pointing to the next element (or end()).
    01156        *
    01157        *  This function will erase the element at the given position and thus
    01158        *  shorten the %deque by one.
    01159        *
    01160        *  The user is cautioned that
    01161        *  this function only erases the element, and that if the element is
    01162        *  itself a pointer, the pointed-to memory is not touched in any way.
    01163        *  Managing the pointer is the user's responsibilty.
    01164        */
    01165       iterator
    01166       erase(iterator __position);
    01167
    01168       /**
    01169        *  @brief  Remove a range of elements.
    01170        *  @param  first  Iterator pointing to the first element to be erased.
    01171        *  @param  last  Iterator pointing to one past the last element to be
    01172        *                erased.
    01173        *  @return  An iterator pointing to the element pointed to by @a last
    01174        *           prior to erasing (or end()).
    01175        *
    01176        *  This function will erase the elements in the range [first,last) and
    01177        *  shorten the %deque accordingly.
    01178        *
    01179        *  The user is cautioned that
    01180        *  this function only erases the elements, and that if the elements
    01181        *  themselves are pointers, the pointed-to memory is not touched in any
    01182        *  way.  Managing the pointer is the user's responsibilty.
    01183        */
    01184       iterator
    01185       erase(iterator __first, iterator __last);
    01186
    01187       /**
    01188        *  @brief  Swaps data with another %deque.
    01189        *  @param  x  A %deque of the same element and allocator types.
    01190        *
    01191        *  This exchanges the elements between two deques in constant time.
    01192        *  (Four pointers, so it should be quite fast.)
    01193        *  Note that the global std::swap() function is specialized such that
    01194        *  std::swap(d1,d2) will feed to this function.
    01195        */
    01196       void
    01197       swap(deque& __x)
    01198       {
    01199     std::swap(this->_M_impl._M_start, __x._M_impl._M_start);
    01200     std::swap(this->_M_impl._M_finish, __x._M_impl._M_finish);
    01201     std::swap(this->_M_impl._M_map, __x._M_impl._M_map);
    01202     std::swap(this->_M_impl._M_map_size, __x._M_impl._M_map_size);
    01203
    01204     // _GLIBCXX_RESOLVE_LIB_DEFECTS
    01205     // 431. Swapping containers with unequal allocators.
    01206     std::__alloc_swap<_Tp_alloc_type>::_S_do_it(_M_get_Tp_allocator(),
    01207                             __x._M_get_Tp_allocator());
    01208       }
    01209
    01210       /**
    01211        *  Erases all the elements.  Note that this function only erases the
    01212        *  elements, and that if the elements themselves are pointers, the
    01213        *  pointed-to memory is not touched in any way.  Managing the pointer is
    01214        *  the user's responsibilty.
    01215        */
    01216       void
    01217       clear()
    01218       { _M_erase_at_end(begin()); }
    01219
    01220     protected:
    01221       // Internal constructor functions follow.
    01222
    01223       // called by the range constructor to implement [23.1.1]/9
    01224       template<typename _Integer>
    01225         void
    01226         _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type)
    01227         {
    01228       _M_initialize_map(__n);
    01229       _M_fill_initialize(__x);
    01230     }
    01231
    01232       // called by the range constructor to implement [23.1.1]/9
    01233       template<typename _InputIterator>
    01234         void
    01235         _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
    01236                    __false_type)
    01237         {
    01238       typedef typename std::iterator_traits<_InputIterator>::
    01239         iterator_category _IterCategory;
    01240       _M_range_initialize(__first, __last, _IterCategory());
    01241     }
    01242
    01243       // called by the second initialize_dispatch above
    01244       //@{
    01245       /**
    01246        *  @if maint
    01247        *  @brief Fills the deque with whatever is in [first,last).
    01248        *  @param  first  An input iterator.
    01249        *  @param  last  An input iterator.
    01250        *  @return   Nothing.
    01251        *
    01252        *  If the iterators are actually forward iterators (or better), then the
    01253        *  memory layout can be done all at once.  Else we move forward using
    01254        *  push_back on each value from the iterator.
    01255        *  @endif
    01256        */
    01257       template<typename _InputIterator>
    01258         void
    01259         _M_range_initialize(_InputIterator __first, _InputIterator __last,
    01260                 std::input_iterator_tag);
    01261
    01262       // called by the second initialize_dispatch above
    01263       template<typename _ForwardIterator>
    01264         void
    01265         _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last,
    01266                 std::forward_iterator_tag);
    01267       //@}
    01268
    01269       /**
    01270        *  @if maint
    01271        *  @brief Fills the %deque with copies of value.
    01272        *  @param  value  Initial value.
    01273        *  @return   Nothing.
    01274        *  @pre _M_start and _M_finish have already been initialized,
    01275        *  but none of the %deque's elements have yet been constructed.
    01276        *
    01277        *  This function is called only when the user provides an explicit size
    01278        *  (with or without an explicit exemplar value).
    01279        *  @endif
    01280        */
    01281       void
    01282       _M_fill_initialize(const value_type& __value);
    01283
    01284       // Internal assign functions follow.  The *_aux functions do the actual
    01285       // assignment work for the range versions.
    01286
    01287       // called by the range assign to implement [23.1.1]/9
    01288       template<typename _Integer>
    01289         void
    01290         _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
    01291         {
    01292       _M_fill_assign(static_cast<size_type>(__n),
    01293              static_cast<value_type>(__val));
    01294     }
    01295
    01296       // called by the range assign to implement [23.1.1]/9
    01297       template<typename _InputIterator>
    01298         void
    01299         _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
    01300                __false_type)
    01301         {
    01302       typedef typename std::iterator_traits<_InputIterator>::
    01303         iterator_category _IterCategory;
    01304       _M_assign_aux(__first, __last, _IterCategory());
    01305     }
    01306
    01307       // called by the second assign_dispatch above
    01308       template<typename _InputIterator>
    01309         void
    01310         _M_assign_aux(_InputIterator __first, _InputIterator __last,
    01311               std::input_iterator_tag);
    01312
    01313       // called by the second assign_dispatch above
    01314       template<typename _ForwardIterator>
    01315         void
    01316         _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,
    01317               std::forward_iterator_tag)
    01318         {
    01319       const size_type __len = std::distance(__first, __last);
    01320       if (__len > size())
    01321         {
    01322           _ForwardIterator __mid = __first;
    01323           std::advance(__mid, size());
    01324           std::copy(__first, __mid, begin());
    01325           insert(end(), __mid, __last);
    01326         }
    01327       else
    01328         _M_erase_at_end(std::copy(__first, __last, begin()));
    01329     }
    01330
    01331       // Called by assign(n,t), and the range assign when it turns out
    01332       // to be the same thing.
    01333       void
    01334       _M_fill_assign(size_type __n, const value_type& __val)
    01335       {
    01336     if (__n > size())
    01337       {
    01338         std::fill(begin(), end(), __val);
    01339         insert(end(), __n - size(), __val);
    01340       }
    01341     else
    01342       {
    01343         _M_erase_at_end(begin() + difference_type(__n));
    01344         std::fill(begin(), end(), __val);
    01345       }
    01346       }
    01347
    01348       //@{
    01349       /**
    01350        *  @if maint
    01351        *  @brief Helper functions for push_* and pop_*.
    01352        *  @endif
    01353        */
    01354       void _M_push_back_aux(const value_type&);
    01355
    01356       void _M_push_front_aux(const value_type&);
    01357
    01358       void _M_pop_back_aux();
    01359
    01360       void _M_pop_front_aux();
    01361       //@}
    01362
    01363       // Internal insert functions follow.  The *_aux functions do the actual
    01364       // insertion work when all shortcuts fail.
    01365
    01366       // called by the range insert to implement [23.1.1]/9
    01367       template<typename _Integer>
    01368         void
    01369         _M_insert_dispatch(iterator __pos,
    01370                _Integer __n, _Integer __x, __true_type)
    01371         {
    01372       _M_fill_insert(__pos, static_cast<size_type>(__n),
    01373              static_cast<value_type>(__x));
    01374     }
    01375
    01376       // called by the range insert to implement [23.1.1]/9
    01377       template<typename _InputIterator>
    01378         void
    01379         _M_insert_dispatch(iterator __pos,
    01380                _InputIterator __first, _InputIterator __last,
    01381                __false_type)
    01382         {
    01383       typedef typename std::iterator_traits<_InputIterator>::
    01384         iterator_category _IterCategory;
    01385           _M_range_insert_aux(__pos, __first, __last, _IterCategory());
    01386     }
    01387
    01388       // called by the second insert_dispatch above
    01389       template<typename _InputIterator>
    01390         void
    01391         _M_range_insert_aux(iterator __pos, _InputIterator __first,
    01392                 _InputIterator __last, std::input_iterator_tag);
    01393
    01394       // called by the second insert_dispatch above
    01395       template<typename _ForwardIterator>
    01396         void
    01397         _M_range_insert_aux(iterator __pos, _ForwardIterator __first,
    01398                 _ForwardIterator __last, std::forward_iterator_tag);
    01399
    01400       // Called by insert(p,n,x), and the range insert when it turns out to be
    01401       // the same thing.  Can use fill functions in optimal situations,
    01402       // otherwise passes off to insert_aux(p,n,x).
    01403       void
    01404       _M_fill_insert(iterator __pos, size_type __n, const value_type& __x);
    01405
    01406       // called by insert(p,x)
    01407       iterator
    01408       _M_insert_aux(iterator __pos, const value_type& __x);
    01409
    01410       // called by insert(p,n,x) via fill_insert
    01411       void
    01412       _M_insert_aux(iterator __pos, size_type __n, const value_type& __x);
    01413
    01414       // called by range_insert_aux for forward iterators
    01415       template<typename _ForwardIterator>
    01416         void
    01417         _M_insert_aux(iterator __pos,
    01418               _ForwardIterator __first, _ForwardIterator __last,
    01419               size_type __n);
    01420
    01421
    01422       // Internal erase functions follow.
    01423
    01424       void
    01425       _M_destroy_data_aux(iterator __first, iterator __last);
    01426
    01427       void
    01428       _M_destroy_data_dispatch(iterator, iterator, __true_type) { }
    01429
    01430       void
    01431       _M_destroy_data_dispatch(iterator __first, iterator __last, __false_type)
    01432       { _M_destroy_data_aux(__first, __last); }
    01433
    01434       // Called by ~deque().
    01435       // NB: Doesn't deallocate the nodes.
    01436       template<typename _Alloc1>
    01437         void
    01438         _M_destroy_data(iterator __first, iterator __last, const _Alloc1&)
    01439         { _M_destroy_data_aux(__first, __last); }
    01440
    01441       void
    01442       _M_destroy_data(iterator __first, iterator __last,
    01443               const std::allocator<_Tp>&)
    01444       {
    01445     typedef typename std::__is_scalar<value_type>::__type
    01446       _Has_trivial_destructor;
    01447     _M_destroy_data_dispatch(__first, __last, _Has_trivial_destructor());
    01448       }
    01449
    01450       // Called by erase(q1, q2).
    01451       void
    01452       _M_erase_at_begin(iterator __pos)
    01453       {
    01454     _M_destroy_data(begin(), __pos, _M_get_Tp_allocator());
    01455     _M_destroy_nodes(this->_M_impl._M_start._M_node, __pos._M_node);
    01456     this->_M_impl._M_start = __pos;
    01457       }
    01458
    01459       // Called by erase(q1, q2), resize(), clear(), _M_assign_aux,
    01460       // _M_fill_assign, operator=.
    01461       void
    01462       _M_erase_at_end(iterator __pos)
    01463       {
    01464     _M_destroy_data(__pos, end(), _M_get_Tp_allocator());
    01465     _M_destroy_nodes(__pos._M_node + 1,
    01466              this->_M_impl._M_finish._M_node + 1);
    01467     this->_M_impl._M_finish = __pos;
    01468       }
    01469
    01470       //@{
    01471       /**
    01472        *  @if maint
    01473        *  @brief Memory-handling helpers for the previous internal insert
    01474        *         functions.
    01475        *  @endif
    01476        */
    01477       iterator
    01478       _M_reserve_elements_at_front(size_type __n)
    01479       {
    01480     const size_type __vacancies = this->_M_impl._M_start._M_cur
    01481                                   - this->_M_impl._M_start._M_first;
    01482     if (__n > __vacancies)
    01483       _M_new_elements_at_front(__n - __vacancies);
    01484     return this->_M_impl._M_start - difference_type(__n);
    01485       }
    01486
    01487       iterator
    01488       _M_reserve_elements_at_back(size_type __n)
    01489       {
    01490     const size_type __vacancies = (this->_M_impl._M_finish._M_last
    01491                        - this->_M_impl._M_finish._M_cur) - 1;
    01492     if (__n > __vacancies)
    01493       _M_new_elements_at_back(__n - __vacancies);
    01494     return this->_M_impl._M_finish + difference_type(__n);
    01495       }
    01496
    01497       void
    01498       _M_new_elements_at_front(size_type __new_elements);
    01499
    01500       void
    01501       _M_new_elements_at_back(size_type __new_elements);
    01502       //@}
    01503
    01504
    01505       //@{
    01506       /**
    01507        *  @if maint
    01508        *  @brief Memory-handling helpers for the major %map.
    01509        *
    01510        *  Makes sure the _M_map has space for new nodes.  Does not
    01511        *  actually add the nodes.  Can invalidate _M_map pointers.
    01512        *  (And consequently, %deque iterators.)
    01513        *  @endif
    01514        */
    01515       void
    01516       _M_reserve_map_at_back(size_type __nodes_to_add = 1)
    01517       {
    01518     if (__nodes_to_add + 1 > this->_M_impl._M_map_size
    01519         - (this->_M_impl._M_finish._M_node - this->_M_impl._M_map))
    01520       _M_reallocate_map(__nodes_to_add, false);
    01521       }
    01522
    01523       void
    01524       _M_reserve_map_at_front(size_type __nodes_to_add = 1)
    01525       {
    01526     if (__nodes_to_add > size_type(this->_M_impl._M_start._M_node
    01527                        - this->_M_impl._M_map))
    01528       _M_reallocate_map(__nodes_to_add, true);
    01529       }
    01530
    01531       void
    01532       _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front);
    01533       //@}
    01534     };
    01535
    01536
    01537   /**
    01538    *  @brief  Deque equality comparison.
    01539    *  @param  x  A %deque.
    01540    *  @param  y  A %deque of the same type as @a x.
    01541    *  @return  True iff the size and elements of the deques are equal.
    01542    *
    01543    *  This is an equivalence relation.  It is linear in the size of the
    01544    *  deques.  Deques are considered equivalent if their sizes are equal,
    01545    *  and if corresponding elements compare equal.
    01546   */
    01547   template<typename _Tp, typename _Alloc>
    01548     inline bool
    01549     operator==(const deque<_Tp, _Alloc>& __x,
    01550                          const deque<_Tp, _Alloc>& __y)
    01551     { return __x.size() == __y.size()
    01552              && std::equal(__x.begin(), __x.end(), __y.begin()); }
    01553
    01554   /**
    01555    *  @brief  Deque ordering relation.
    01556    *  @param  x  A %deque.
    01557    *  @param  y  A %deque of the same type as @a x.
    01558    *  @return  True iff @a x is lexicographically less than @a y.
    01559    *
    01560    *  This is a total ordering relation.  It is linear in the size of the
    01561    *  deques.  The elements must be comparable with @c <.
    01562    *
    01563    *  See std::lexicographical_compare() for how the determination is made.
    01564   */
    01565   template<typename _Tp, typename _Alloc>
    01566     inline bool
    01567     operator<(const deque<_Tp, _Alloc>& __x,
    01568           const deque<_Tp, _Alloc>& __y)
    01569     { return std::lexicographical_compare(__x.begin(), __x.end(),
    01570                       __y.begin(), __y.end()); }
    01571
    01572   /// Based on operator==
    01573   template<typename _Tp, typename _Alloc>
    01574     inline bool
    01575     operator!=(const deque<_Tp, _Alloc>& __x,
    01576            const deque<_Tp, _Alloc>& __y)
    01577     { return !(__x == __y); }
    01578
    01579   /// Based on operator<
    01580   template<typename _Tp, typename _Alloc>
    01581     inline bool
    01582     operator>(const deque<_Tp, _Alloc>& __x,
    01583           const deque<_Tp, _Alloc>& __y)
    01584     { return __y < __x; }
    01585
    01586   /// Based on operator<
    01587   template<typename _Tp, typename _Alloc>
    01588     inline bool
    01589     operator<=(const deque<_Tp, _Alloc>& __x,
    01590            const deque<_Tp, _Alloc>& __y)
    01591     { return !(__y < __x); }
    01592
    01593   /// Based on operator<
    01594   template<typename _Tp, typename _Alloc>
    01595     inline bool
    01596     operator>=(const deque<_Tp, _Alloc>& __x,
    01597            const deque<_Tp, _Alloc>& __y)
    01598     { return !(__x < __y); }
    01599
    01600   /// See std::deque::swap().
    01601   template<typename _Tp, typename _Alloc>
    01602     inline void
    01603     swap(deque<_Tp,_Alloc>& __x, deque<_Tp,_Alloc>& __y)
    01604     { __x.swap(__y); }
    01605
    01606 _GLIBCXX_END_NESTED_NAMESPACE
    01607
    01608 #endif /* _DEQUE_H */