libstdc++
stl_deque.h
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00001 // Deque implementation -*- C++ -*-
00002 
00003 // Copyright (C) 2001-2018 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 3, 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 // Under Section 7 of GPL version 3, you are granted additional
00017 // permissions described in the GCC Runtime Library Exception, version
00018 // 3.1, as published by the Free Software Foundation.
00019 
00020 // You should have received a copy of the GNU General Public License and
00021 // a copy of the GCC Runtime Library Exception along with this program;
00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00023 // <http://www.gnu.org/licenses/>.
00024 
00025 /*
00026  *
00027  * Copyright (c) 1994
00028  * Hewlett-Packard Company
00029  *
00030  * Permission to use, copy, modify, distribute and sell this software
00031  * and its documentation for any purpose is hereby granted without fee,
00032  * provided that the above copyright notice appear in all copies and
00033  * that both that copyright notice and this permission notice appear
00034  * in supporting documentation.  Hewlett-Packard Company makes no
00035  * representations about the suitability of this software for any
00036  * purpose.  It is provided "as is" without express or implied warranty.
00037  *
00038  *
00039  * Copyright (c) 1997
00040  * Silicon Graphics Computer Systems, Inc.
00041  *
00042  * Permission to use, copy, modify, distribute and sell this software
00043  * and its documentation for any purpose is hereby granted without fee,
00044  * provided that the above copyright notice appear in all copies and
00045  * that both that copyright notice and this permission notice appear
00046  * in supporting documentation.  Silicon Graphics makes no
00047  * representations about the suitability of this software for any
00048  * purpose.  It is provided "as is" without express or implied warranty.
00049  */
00050 
00051 /** @file bits/stl_deque.h
00052  *  This is an internal header file, included by other library headers.
00053  *  Do not attempt to use it directly. @headername{deque}
00054  */
00055 
00056 #ifndef _STL_DEQUE_H
00057 #define _STL_DEQUE_H 1
00058 
00059 #include <bits/concept_check.h>
00060 #include <bits/stl_iterator_base_types.h>
00061 #include <bits/stl_iterator_base_funcs.h>
00062 #if __cplusplus >= 201103L
00063 #include <initializer_list>
00064 #endif
00065 
00066 #include <debug/assertions.h>
00067 
00068 namespace std _GLIBCXX_VISIBILITY(default)
00069 {
00070 _GLIBCXX_BEGIN_NAMESPACE_VERSION
00071 _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
00072 
00073   /**
00074    *  @brief This function controls the size of memory nodes.
00075    *  @param  __size  The size of an element.
00076    *  @return   The number (not byte size) of elements per node.
00077    *
00078    *  This function started off as a compiler kludge from SGI, but
00079    *  seems to be a useful wrapper around a repeated constant
00080    *  expression.  The @b 512 is tunable (and no other code needs to
00081    *  change), but no investigation has been done since inheriting the
00082    *  SGI code.  Touch _GLIBCXX_DEQUE_BUF_SIZE only if you know what
00083    *  you are doing, however: changing it breaks the binary
00084    *  compatibility!!
00085   */
00086 
00087 #ifndef _GLIBCXX_DEQUE_BUF_SIZE
00088 #define _GLIBCXX_DEQUE_BUF_SIZE 512
00089 #endif
00090 
00091   _GLIBCXX_CONSTEXPR inline size_t
00092   __deque_buf_size(size_t __size)
00093   { return (__size < _GLIBCXX_DEQUE_BUF_SIZE
00094             ? size_t(_GLIBCXX_DEQUE_BUF_SIZE / __size) : size_t(1)); }
00095 
00096 
00097   /**
00098    *  @brief A deque::iterator.
00099    *
00100    *  Quite a bit of intelligence here.  Much of the functionality of
00101    *  deque is actually passed off to this class.  A deque holds two
00102    *  of these internally, marking its valid range.  Access to
00103    *  elements is done as offsets of either of those two, relying on
00104    *  operator overloading in this class.
00105    *
00106    *  All the functions are op overloads except for _M_set_node.
00107   */
00108   template<typename _Tp, typename _Ref, typename _Ptr>
00109     struct _Deque_iterator
00110     {
00111 #if __cplusplus < 201103L
00112       typedef _Deque_iterator<_Tp, _Tp&, _Tp*>       iterator;
00113       typedef _Deque_iterator<_Tp, const _Tp&, const _Tp*> const_iterator;
00114       typedef _Tp*                                       _Elt_pointer;
00115       typedef _Tp**                                     _Map_pointer;
00116 #else
00117     private:
00118       template<typename _Up>
00119         using __ptr_to = typename pointer_traits<_Ptr>::template rebind<_Up>;
00120       template<typename _CvTp>
00121         using __iter = _Deque_iterator<_Tp, _CvTp&, __ptr_to<_CvTp>>;
00122     public:
00123       typedef __iter<_Tp>               iterator;
00124       typedef __iter<const _Tp>         const_iterator;
00125       typedef __ptr_to<_Tp>             _Elt_pointer;
00126       typedef __ptr_to<_Elt_pointer>    _Map_pointer;
00127 #endif
00128 
00129       static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT
00130       { return __deque_buf_size(sizeof(_Tp)); }
00131 
00132       typedef std::random_access_iterator_tag   iterator_category;
00133       typedef _Tp                               value_type;
00134       typedef _Ptr                              pointer;
00135       typedef _Ref                              reference;
00136       typedef size_t                            size_type;
00137       typedef ptrdiff_t                         difference_type;
00138       typedef _Deque_iterator                   _Self;
00139 
00140       _Elt_pointer _M_cur;
00141       _Elt_pointer _M_first;
00142       _Elt_pointer _M_last;
00143       _Map_pointer _M_node;
00144 
00145       _Deque_iterator(_Elt_pointer __x, _Map_pointer __y) _GLIBCXX_NOEXCEPT
00146       : _M_cur(__x), _M_first(*__y),
00147         _M_last(*__y + _S_buffer_size()), _M_node(__y) { }
00148 
00149       _Deque_iterator() _GLIBCXX_NOEXCEPT
00150       : _M_cur(), _M_first(), _M_last(), _M_node() { }
00151 
00152       _Deque_iterator(const iterator& __x) _GLIBCXX_NOEXCEPT
00153       : _M_cur(__x._M_cur), _M_first(__x._M_first),
00154         _M_last(__x._M_last), _M_node(__x._M_node) { }
00155 
00156       iterator
00157       _M_const_cast() const _GLIBCXX_NOEXCEPT
00158       { return iterator(_M_cur, _M_node); }
00159 
00160       reference
00161       operator*() const _GLIBCXX_NOEXCEPT
00162       { return *_M_cur; }
00163 
00164       pointer
00165       operator->() const _GLIBCXX_NOEXCEPT
00166       { return _M_cur; }
00167 
00168       _Self&
00169       operator++() _GLIBCXX_NOEXCEPT
00170       {
00171         ++_M_cur;
00172         if (_M_cur == _M_last)
00173           {
00174             _M_set_node(_M_node + 1);
00175             _M_cur = _M_first;
00176           }
00177         return *this;
00178       }
00179 
00180       _Self
00181       operator++(int) _GLIBCXX_NOEXCEPT
00182       {
00183         _Self __tmp = *this;
00184         ++*this;
00185         return __tmp;
00186       }
00187 
00188       _Self&
00189       operator--() _GLIBCXX_NOEXCEPT
00190       {
00191         if (_M_cur == _M_first)
00192           {
00193             _M_set_node(_M_node - 1);
00194             _M_cur = _M_last;
00195           }
00196         --_M_cur;
00197         return *this;
00198       }
00199 
00200       _Self
00201       operator--(int) _GLIBCXX_NOEXCEPT
00202       {
00203         _Self __tmp = *this;
00204         --*this;
00205         return __tmp;
00206       }
00207 
00208       _Self&
00209       operator+=(difference_type __n) _GLIBCXX_NOEXCEPT
00210       {
00211         const difference_type __offset = __n + (_M_cur - _M_first);
00212         if (__offset >= 0 && __offset < difference_type(_S_buffer_size()))
00213           _M_cur += __n;
00214         else
00215           {
00216             const difference_type __node_offset =
00217               __offset > 0 ? __offset / difference_type(_S_buffer_size())
00218                            : -difference_type((-__offset - 1)
00219                                               / _S_buffer_size()) - 1;
00220             _M_set_node(_M_node + __node_offset);
00221             _M_cur = _M_first + (__offset - __node_offset
00222                                  * difference_type(_S_buffer_size()));
00223           }
00224         return *this;
00225       }
00226 
00227       _Self
00228       operator+(difference_type __n) const _GLIBCXX_NOEXCEPT
00229       {
00230         _Self __tmp = *this;
00231         return __tmp += __n;
00232       }
00233 
00234       _Self&
00235       operator-=(difference_type __n) _GLIBCXX_NOEXCEPT
00236       { return *this += -__n; }
00237 
00238       _Self
00239       operator-(difference_type __n) const _GLIBCXX_NOEXCEPT
00240       {
00241         _Self __tmp = *this;
00242         return __tmp -= __n;
00243       }
00244 
00245       reference
00246       operator[](difference_type __n) const _GLIBCXX_NOEXCEPT
00247       { return *(*this + __n); }
00248 
00249       /**
00250        *  Prepares to traverse new_node.  Sets everything except
00251        *  _M_cur, which should therefore be set by the caller
00252        *  immediately afterwards, based on _M_first and _M_last.
00253        */
00254       void
00255       _M_set_node(_Map_pointer __new_node) _GLIBCXX_NOEXCEPT
00256       {
00257         _M_node = __new_node;
00258         _M_first = *__new_node;
00259         _M_last = _M_first + difference_type(_S_buffer_size());
00260       }
00261     };
00262 
00263   // Note: we also provide overloads whose operands are of the same type in
00264   // order to avoid ambiguous overload resolution when std::rel_ops operators
00265   // are in scope (for additional details, see libstdc++/3628)
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) _GLIBCXX_NOEXCEPT
00270     { return __x._M_cur == __y._M_cur; }
00271 
00272   template<typename _Tp, typename _RefL, typename _PtrL,
00273            typename _RefR, typename _PtrR>
00274     inline bool
00275     operator==(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
00276                const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
00277     { return __x._M_cur == __y._M_cur; }
00278 
00279   template<typename _Tp, typename _Ref, typename _Ptr>
00280     inline bool
00281     operator!=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
00282                const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
00283     { return !(__x == __y); }
00284 
00285   template<typename _Tp, typename _RefL, typename _PtrL,
00286            typename _RefR, typename _PtrR>
00287     inline bool
00288     operator!=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
00289                const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
00290     { return !(__x == __y); }
00291 
00292   template<typename _Tp, typename _Ref, typename _Ptr>
00293     inline bool
00294     operator<(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
00295               const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
00296     { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur)
00297                                           : (__x._M_node < __y._M_node); }
00298 
00299   template<typename _Tp, typename _RefL, typename _PtrL,
00300            typename _RefR, typename _PtrR>
00301     inline bool
00302     operator<(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
00303               const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
00304     { return (__x._M_node == __y._M_node) ? (__x._M_cur < __y._M_cur)
00305                                           : (__x._M_node < __y._M_node); }
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) _GLIBCXX_NOEXCEPT
00311     { return __y < __x; }
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) _GLIBCXX_NOEXCEPT
00318     { return __y < __x; }
00319 
00320   template<typename _Tp, typename _Ref, typename _Ptr>
00321     inline bool
00322     operator<=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
00323                const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
00324     { return !(__y < __x); }
00325 
00326   template<typename _Tp, typename _RefL, typename _PtrL,
00327            typename _RefR, typename _PtrR>
00328     inline bool
00329     operator<=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
00330                const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
00331     { return !(__y < __x); }
00332 
00333   template<typename _Tp, typename _Ref, typename _Ptr>
00334     inline bool
00335     operator>=(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
00336                const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
00337     { return !(__x < __y); }
00338 
00339   template<typename _Tp, typename _RefL, typename _PtrL,
00340            typename _RefR, typename _PtrR>
00341     inline bool
00342     operator>=(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
00343                const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
00344     { return !(__x < __y); }
00345 
00346   // _GLIBCXX_RESOLVE_LIB_DEFECTS
00347   // According to the resolution of DR179 not only the various comparison
00348   // operators but also operator- must accept mixed iterator/const_iterator
00349   // parameters.
00350   template<typename _Tp, typename _Ref, typename _Ptr>
00351     inline typename _Deque_iterator<_Tp, _Ref, _Ptr>::difference_type
00352     operator-(const _Deque_iterator<_Tp, _Ref, _Ptr>& __x,
00353               const _Deque_iterator<_Tp, _Ref, _Ptr>& __y) _GLIBCXX_NOEXCEPT
00354     {
00355       return typename _Deque_iterator<_Tp, _Ref, _Ptr>::difference_type
00356         (_Deque_iterator<_Tp, _Ref, _Ptr>::_S_buffer_size())
00357         * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first)
00358         + (__y._M_last - __y._M_cur);
00359     }
00360 
00361   template<typename _Tp, typename _RefL, typename _PtrL,
00362            typename _RefR, typename _PtrR>
00363     inline typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
00364     operator-(const _Deque_iterator<_Tp, _RefL, _PtrL>& __x,
00365               const _Deque_iterator<_Tp, _RefR, _PtrR>& __y) _GLIBCXX_NOEXCEPT
00366     {
00367       return typename _Deque_iterator<_Tp, _RefL, _PtrL>::difference_type
00368         (_Deque_iterator<_Tp, _RefL, _PtrL>::_S_buffer_size())
00369         * (__x._M_node - __y._M_node - 1) + (__x._M_cur - __x._M_first)
00370         + (__y._M_last - __y._M_cur);
00371     }
00372 
00373   template<typename _Tp, typename _Ref, typename _Ptr>
00374     inline _Deque_iterator<_Tp, _Ref, _Ptr>
00375     operator+(ptrdiff_t __n, const _Deque_iterator<_Tp, _Ref, _Ptr>& __x)
00376     _GLIBCXX_NOEXCEPT
00377     { return __x + __n; }
00378 
00379   template<typename _Tp>
00380     void
00381     fill(const _Deque_iterator<_Tp, _Tp&, _Tp*>&,
00382          const _Deque_iterator<_Tp, _Tp&, _Tp*>&, const _Tp&);
00383 
00384   template<typename _Tp>
00385     _Deque_iterator<_Tp, _Tp&, _Tp*>
00386     copy(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
00387          _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
00388          _Deque_iterator<_Tp, _Tp&, _Tp*>);
00389 
00390   template<typename _Tp>
00391     inline _Deque_iterator<_Tp, _Tp&, _Tp*>
00392     copy(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
00393          _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
00394          _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
00395     { return std::copy(_Deque_iterator<_Tp, const _Tp&, const _Tp*>(__first),
00396                        _Deque_iterator<_Tp, const _Tp&, const _Tp*>(__last),
00397                        __result); }
00398 
00399   template<typename _Tp>
00400     _Deque_iterator<_Tp, _Tp&, _Tp*>
00401     copy_backward(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
00402                   _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
00403                   _Deque_iterator<_Tp, _Tp&, _Tp*>);
00404 
00405   template<typename _Tp>
00406     inline _Deque_iterator<_Tp, _Tp&, _Tp*>
00407     copy_backward(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
00408                   _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
00409                   _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
00410     { return std::copy_backward(_Deque_iterator<_Tp,
00411                                 const _Tp&, const _Tp*>(__first),
00412                                 _Deque_iterator<_Tp,
00413                                 const _Tp&, const _Tp*>(__last),
00414                                 __result); }
00415 
00416 #if __cplusplus >= 201103L
00417   template<typename _Tp>
00418     _Deque_iterator<_Tp, _Tp&, _Tp*>
00419     move(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
00420          _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
00421          _Deque_iterator<_Tp, _Tp&, _Tp*>);
00422 
00423   template<typename _Tp>
00424     inline _Deque_iterator<_Tp, _Tp&, _Tp*>
00425     move(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
00426          _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
00427          _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
00428     { return std::move(_Deque_iterator<_Tp, const _Tp&, const _Tp*>(__first),
00429                        _Deque_iterator<_Tp, const _Tp&, const _Tp*>(__last),
00430                        __result); }
00431 
00432   template<typename _Tp>
00433     _Deque_iterator<_Tp, _Tp&, _Tp*>
00434     move_backward(_Deque_iterator<_Tp, const _Tp&, const _Tp*>,
00435                   _Deque_iterator<_Tp, const _Tp&, const _Tp*>,
00436                   _Deque_iterator<_Tp, _Tp&, _Tp*>);
00437 
00438   template<typename _Tp>
00439     inline _Deque_iterator<_Tp, _Tp&, _Tp*>
00440     move_backward(_Deque_iterator<_Tp, _Tp&, _Tp*> __first,
00441                   _Deque_iterator<_Tp, _Tp&, _Tp*> __last,
00442                   _Deque_iterator<_Tp, _Tp&, _Tp*> __result)
00443     { return std::move_backward(_Deque_iterator<_Tp,
00444                                 const _Tp&, const _Tp*>(__first),
00445                                 _Deque_iterator<_Tp,
00446                                 const _Tp&, const _Tp*>(__last),
00447                                 __result); }
00448 #endif
00449 
00450   /**
00451    *  Deque base class.  This class provides the unified face for %deque's
00452    *  allocation.  This class's constructor and destructor allocate and
00453    *  deallocate (but do not initialize) storage.  This makes %exception
00454    *  safety easier.
00455    *
00456    *  Nothing in this class ever constructs or destroys an actual Tp element.
00457    *  (Deque handles that itself.)  Only/All memory management is performed
00458    *  here.
00459   */
00460   template<typename _Tp, typename _Alloc>
00461     class _Deque_base
00462     {
00463     protected:
00464       typedef typename __gnu_cxx::__alloc_traits<_Alloc>::template
00465         rebind<_Tp>::other _Tp_alloc_type;
00466       typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type>  _Alloc_traits;
00467 
00468 #if __cplusplus < 201103L
00469       typedef _Tp*                                      _Ptr;
00470       typedef const _Tp*                                _Ptr_const;
00471 #else
00472       typedef typename _Alloc_traits::pointer           _Ptr;
00473       typedef typename _Alloc_traits::const_pointer     _Ptr_const;
00474 #endif
00475 
00476       typedef typename _Alloc_traits::template rebind<_Ptr>::other
00477         _Map_alloc_type;
00478       typedef __gnu_cxx::__alloc_traits<_Map_alloc_type> _Map_alloc_traits;
00479 
00480     public:
00481       typedef _Alloc              allocator_type;
00482       typedef typename _Alloc_traits::size_type size_type;
00483 
00484       allocator_type
00485       get_allocator() const _GLIBCXX_NOEXCEPT
00486       { return allocator_type(_M_get_Tp_allocator()); }
00487 
00488       typedef _Deque_iterator<_Tp, _Tp&, _Ptr>    iterator;
00489       typedef _Deque_iterator<_Tp, const _Tp&, _Ptr_const>   const_iterator;
00490 
00491       _Deque_base()
00492       : _M_impl()
00493       { _M_initialize_map(0); }
00494 
00495       _Deque_base(size_t __num_elements)
00496       : _M_impl()
00497       { _M_initialize_map(__num_elements); }
00498 
00499       _Deque_base(const allocator_type& __a, size_t __num_elements)
00500       : _M_impl(__a)
00501       { _M_initialize_map(__num_elements); }
00502 
00503       _Deque_base(const allocator_type& __a)
00504       : _M_impl(__a)
00505       { /* Caller must initialize map. */ }
00506 
00507 #if __cplusplus >= 201103L
00508       _Deque_base(_Deque_base&& __x, false_type)
00509       : _M_impl(__x._M_move_impl())
00510       { }
00511 
00512       _Deque_base(_Deque_base&& __x, true_type)
00513       : _M_impl(std::move(__x._M_get_Tp_allocator()))
00514       {
00515         _M_initialize_map(0);
00516         if (__x._M_impl._M_map)
00517           this->_M_impl._M_swap_data(__x._M_impl);
00518       }
00519 
00520       _Deque_base(_Deque_base&& __x)
00521       : _Deque_base(std::move(__x), typename _Alloc_traits::is_always_equal{})
00522       { }
00523 
00524       _Deque_base(_Deque_base&& __x, const allocator_type& __a, size_type __n)
00525       : _M_impl(__a)
00526       {
00527         if (__x.get_allocator() == __a)
00528           {
00529             if (__x._M_impl._M_map)
00530               {
00531                 _M_initialize_map(0);
00532                 this->_M_impl._M_swap_data(__x._M_impl);
00533               }
00534           }
00535         else
00536           {
00537             _M_initialize_map(__n);
00538           }
00539       }
00540 #endif
00541 
00542       ~_Deque_base() _GLIBCXX_NOEXCEPT;
00543 
00544     protected:
00545       typedef typename iterator::_Map_pointer _Map_pointer;
00546 
00547       //This struct encapsulates the implementation of the std::deque
00548       //standard container and at the same time makes use of the EBO
00549       //for empty allocators.
00550       struct _Deque_impl
00551       : public _Tp_alloc_type
00552       {
00553         _Map_pointer _M_map;
00554         size_t _M_map_size;
00555         iterator _M_start;
00556         iterator _M_finish;
00557 
00558         _Deque_impl()
00559         : _Tp_alloc_type(), _M_map(), _M_map_size(0),
00560           _M_start(), _M_finish()
00561         { }
00562 
00563         _Deque_impl(const _Tp_alloc_type& __a) _GLIBCXX_NOEXCEPT
00564         : _Tp_alloc_type(__a), _M_map(), _M_map_size(0),
00565           _M_start(), _M_finish()
00566         { }
00567 
00568 #if __cplusplus >= 201103L
00569         _Deque_impl(_Deque_impl&&) = default;
00570 
00571         _Deque_impl(_Tp_alloc_type&& __a) noexcept
00572         : _Tp_alloc_type(std::move(__a)), _M_map(), _M_map_size(0),
00573           _M_start(), _M_finish()
00574         { }
00575 #endif
00576 
00577         void _M_swap_data(_Deque_impl& __x) _GLIBCXX_NOEXCEPT
00578         {
00579           using std::swap;
00580           swap(this->_M_start, __x._M_start);
00581           swap(this->_M_finish, __x._M_finish);
00582           swap(this->_M_map, __x._M_map);
00583           swap(this->_M_map_size, __x._M_map_size);
00584         }
00585       };
00586 
00587       _Tp_alloc_type&
00588       _M_get_Tp_allocator() _GLIBCXX_NOEXCEPT
00589       { return *static_cast<_Tp_alloc_type*>(&this->_M_impl); }
00590 
00591       const _Tp_alloc_type&
00592       _M_get_Tp_allocator() const _GLIBCXX_NOEXCEPT
00593       { return *static_cast<const _Tp_alloc_type*>(&this->_M_impl); }
00594 
00595       _Map_alloc_type
00596       _M_get_map_allocator() const _GLIBCXX_NOEXCEPT
00597       { return _Map_alloc_type(_M_get_Tp_allocator()); }
00598 
00599       _Ptr
00600       _M_allocate_node()
00601       {
00602         typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits;
00603         return _Traits::allocate(_M_impl, __deque_buf_size(sizeof(_Tp)));
00604       }
00605 
00606       void
00607       _M_deallocate_node(_Ptr __p) _GLIBCXX_NOEXCEPT
00608       {
00609         typedef __gnu_cxx::__alloc_traits<_Tp_alloc_type> _Traits;
00610         _Traits::deallocate(_M_impl, __p, __deque_buf_size(sizeof(_Tp)));
00611       }
00612 
00613       _Map_pointer
00614       _M_allocate_map(size_t __n)
00615       {
00616         _Map_alloc_type __map_alloc = _M_get_map_allocator();
00617         return _Map_alloc_traits::allocate(__map_alloc, __n);
00618       }
00619 
00620       void
00621       _M_deallocate_map(_Map_pointer __p, size_t __n) _GLIBCXX_NOEXCEPT
00622       {
00623         _Map_alloc_type __map_alloc = _M_get_map_allocator();
00624         _Map_alloc_traits::deallocate(__map_alloc, __p, __n);
00625       }
00626 
00627     protected:
00628       void _M_initialize_map(size_t);
00629       void _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish);
00630       void _M_destroy_nodes(_Map_pointer __nstart,
00631                             _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT;
00632       enum { _S_initial_map_size = 8 };
00633 
00634       _Deque_impl _M_impl;
00635 
00636 #if __cplusplus >= 201103L
00637     private:
00638       _Deque_impl
00639       _M_move_impl()
00640       {
00641         if (!_M_impl._M_map)
00642           return std::move(_M_impl);
00643 
00644         // Create a copy of the current allocator.
00645         _Tp_alloc_type __alloc{_M_get_Tp_allocator()};
00646         // Put that copy in a moved-from state.
00647         _Tp_alloc_type __sink __attribute((__unused__)) {std::move(__alloc)};
00648         // Create an empty map that allocates using the moved-from allocator.
00649         _Deque_base __empty{__alloc};
00650         __empty._M_initialize_map(0);
00651         // Now safe to modify current allocator and perform non-throwing swaps.
00652         _Deque_impl __ret{std::move(_M_get_Tp_allocator())};
00653         _M_impl._M_swap_data(__ret);
00654         _M_impl._M_swap_data(__empty._M_impl);
00655         return __ret;
00656       }
00657 #endif
00658     };
00659 
00660   template<typename _Tp, typename _Alloc>
00661     _Deque_base<_Tp, _Alloc>::
00662     ~_Deque_base() _GLIBCXX_NOEXCEPT
00663     {
00664       if (this->_M_impl._M_map)
00665         {
00666           _M_destroy_nodes(this->_M_impl._M_start._M_node,
00667                            this->_M_impl._M_finish._M_node + 1);
00668           _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
00669         }
00670     }
00671 
00672   /**
00673    *  @brief Layout storage.
00674    *  @param  __num_elements  The count of T's for which to allocate space
00675    *                          at first.
00676    *  @return   Nothing.
00677    *
00678    *  The initial underlying memory layout is a bit complicated...
00679   */
00680   template<typename _Tp, typename _Alloc>
00681     void
00682     _Deque_base<_Tp, _Alloc>::
00683     _M_initialize_map(size_t __num_elements)
00684     {
00685       const size_t __num_nodes = (__num_elements/ __deque_buf_size(sizeof(_Tp))
00686                                   + 1);
00687 
00688       this->_M_impl._M_map_size = std::max((size_t) _S_initial_map_size,
00689                                            size_t(__num_nodes + 2));
00690       this->_M_impl._M_map = _M_allocate_map(this->_M_impl._M_map_size);
00691 
00692       // For "small" maps (needing less than _M_map_size nodes), allocation
00693       // starts in the middle elements and grows outwards.  So nstart may be
00694       // the beginning of _M_map, but for small maps it may be as far in as
00695       // _M_map+3.
00696 
00697       _Map_pointer __nstart = (this->_M_impl._M_map
00698                                + (this->_M_impl._M_map_size - __num_nodes) / 2);
00699       _Map_pointer __nfinish = __nstart + __num_nodes;
00700 
00701       __try
00702         { _M_create_nodes(__nstart, __nfinish); }
00703       __catch(...)
00704         {
00705           _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
00706           this->_M_impl._M_map = _Map_pointer();
00707           this->_M_impl._M_map_size = 0;
00708           __throw_exception_again;
00709         }
00710 
00711       this->_M_impl._M_start._M_set_node(__nstart);
00712       this->_M_impl._M_finish._M_set_node(__nfinish - 1);
00713       this->_M_impl._M_start._M_cur = _M_impl._M_start._M_first;
00714       this->_M_impl._M_finish._M_cur = (this->_M_impl._M_finish._M_first
00715                                         + __num_elements
00716                                         % __deque_buf_size(sizeof(_Tp)));
00717     }
00718 
00719   template<typename _Tp, typename _Alloc>
00720     void
00721     _Deque_base<_Tp, _Alloc>::
00722     _M_create_nodes(_Map_pointer __nstart, _Map_pointer __nfinish)
00723     {
00724       _Map_pointer __cur;
00725       __try
00726         {
00727           for (__cur = __nstart; __cur < __nfinish; ++__cur)
00728             *__cur = this->_M_allocate_node();
00729         }
00730       __catch(...)
00731         {
00732           _M_destroy_nodes(__nstart, __cur);
00733           __throw_exception_again;
00734         }
00735     }
00736 
00737   template<typename _Tp, typename _Alloc>
00738     void
00739     _Deque_base<_Tp, _Alloc>::
00740     _M_destroy_nodes(_Map_pointer __nstart,
00741                      _Map_pointer __nfinish) _GLIBCXX_NOEXCEPT
00742     {
00743       for (_Map_pointer __n = __nstart; __n < __nfinish; ++__n)
00744         _M_deallocate_node(*__n);
00745     }
00746 
00747   /**
00748    *  @brief  A standard container using fixed-size memory allocation and
00749    *  constant-time manipulation of elements at either end.
00750    *
00751    *  @ingroup sequences
00752    *
00753    *  @tparam _Tp  Type of element.
00754    *  @tparam _Alloc  Allocator type, defaults to allocator<_Tp>.
00755    *
00756    *  Meets the requirements of a <a href="tables.html#65">container</a>, a
00757    *  <a href="tables.html#66">reversible container</a>, and a
00758    *  <a href="tables.html#67">sequence</a>, including the
00759    *  <a href="tables.html#68">optional sequence requirements</a>.
00760    *
00761    *  In previous HP/SGI versions of deque, there was an extra template
00762    *  parameter so users could control the node size.  This extension turned
00763    *  out to violate the C++ standard (it can be detected using template
00764    *  template parameters), and it was removed.
00765    *
00766    *  Here's how a deque<Tp> manages memory.  Each deque has 4 members:
00767    *
00768    *  - Tp**        _M_map
00769    *  - size_t      _M_map_size
00770    *  - iterator    _M_start, _M_finish
00771    *
00772    *  map_size is at least 8.  %map is an array of map_size
00773    *  pointers-to-@a nodes.  (The name %map has nothing to do with the
00774    *  std::map class, and @b nodes should not be confused with
00775    *  std::list's usage of @a node.)
00776    *
00777    *  A @a node has no specific type name as such, but it is referred
00778    *  to as @a node in this file.  It is a simple array-of-Tp.  If Tp
00779    *  is very large, there will be one Tp element per node (i.e., an
00780    *  @a array of one).  For non-huge Tp's, node size is inversely
00781    *  related to Tp size: the larger the Tp, the fewer Tp's will fit
00782    *  in a node.  The goal here is to keep the total size of a node
00783    *  relatively small and constant over different Tp's, to improve
00784    *  allocator efficiency.
00785    *
00786    *  Not every pointer in the %map array will point to a node.  If
00787    *  the initial number of elements in the deque is small, the
00788    *  /middle/ %map pointers will be valid, and the ones at the edges
00789    *  will be unused.  This same situation will arise as the %map
00790    *  grows: available %map pointers, if any, will be on the ends.  As
00791    *  new nodes are created, only a subset of the %map's pointers need
00792    *  to be copied @a outward.
00793    *
00794    *  Class invariants:
00795    * - For any nonsingular iterator i:
00796    *    - i.node points to a member of the %map array.  (Yes, you read that
00797    *      correctly:  i.node does not actually point to a node.)  The member of
00798    *      the %map array is what actually points to the node.
00799    *    - i.first == *(i.node)    (This points to the node (first Tp element).)
00800    *    - i.last  == i.first + node_size
00801    *    - i.cur is a pointer in the range [i.first, i.last).  NOTE:
00802    *      the implication of this is that i.cur is always a dereferenceable
00803    *      pointer, even if i is a past-the-end iterator.
00804    * - Start and Finish are always nonsingular iterators.  NOTE: this
00805    * means that an empty deque must have one node, a deque with <N
00806    * elements (where N is the node buffer size) must have one node, a
00807    * deque with N through (2N-1) elements must have two nodes, etc.
00808    * - For every node other than start.node and finish.node, every
00809    * element in the node is an initialized object.  If start.node ==
00810    * finish.node, then [start.cur, finish.cur) are initialized
00811    * objects, and the elements outside that range are uninitialized
00812    * storage.  Otherwise, [start.cur, start.last) and [finish.first,
00813    * finish.cur) are initialized objects, and [start.first, start.cur)
00814    * and [finish.cur, finish.last) are uninitialized storage.
00815    * - [%map, %map + map_size) is a valid, non-empty range.
00816    * - [start.node, finish.node] is a valid range contained within
00817    *   [%map, %map + map_size).
00818    * - A pointer in the range [%map, %map + map_size) points to an allocated
00819    *   node if and only if the pointer is in the range
00820    *   [start.node, finish.node].
00821    *
00822    *  Here's the magic:  nothing in deque is @b aware of the discontiguous
00823    *  storage!
00824    *
00825    *  The memory setup and layout occurs in the parent, _Base, and the iterator
00826    *  class is entirely responsible for @a leaping from one node to the next.
00827    *  All the implementation routines for deque itself work only through the
00828    *  start and finish iterators.  This keeps the routines simple and sane,
00829    *  and we can use other standard algorithms as well.
00830   */
00831   template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
00832     class deque : protected _Deque_base<_Tp, _Alloc>
00833     {
00834 #ifdef _GLIBCXX_CONCEPT_CHECKS
00835       // concept requirements
00836       typedef typename _Alloc::value_type       _Alloc_value_type;
00837 # if __cplusplus < 201103L
00838       __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
00839 # endif
00840       __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept)
00841 #endif
00842 
00843 #if __cplusplus >= 201103L
00844       static_assert(is_same<typename remove_cv<_Tp>::type, _Tp>::value,
00845           "std::deque must have a non-const, non-volatile value_type");
00846 # ifdef __STRICT_ANSI__
00847       static_assert(is_same<typename _Alloc::value_type, _Tp>::value,
00848           "std::deque must have the same value_type as its allocator");
00849 # endif
00850 #endif
00851 
00852       typedef _Deque_base<_Tp, _Alloc>                  _Base;
00853       typedef typename _Base::_Tp_alloc_type            _Tp_alloc_type;
00854       typedef typename _Base::_Alloc_traits             _Alloc_traits;
00855       typedef typename _Base::_Map_pointer              _Map_pointer;
00856 
00857     public:
00858       typedef _Tp                                       value_type;
00859       typedef typename _Alloc_traits::pointer           pointer;
00860       typedef typename _Alloc_traits::const_pointer     const_pointer;
00861       typedef typename _Alloc_traits::reference         reference;
00862       typedef typename _Alloc_traits::const_reference   const_reference;
00863       typedef typename _Base::iterator                  iterator;
00864       typedef typename _Base::const_iterator            const_iterator;
00865       typedef std::reverse_iterator<const_iterator>     const_reverse_iterator;
00866       typedef std::reverse_iterator<iterator>           reverse_iterator;
00867       typedef size_t                                    size_type;
00868       typedef ptrdiff_t                                 difference_type;
00869       typedef _Alloc                                    allocator_type;
00870 
00871     protected:
00872       static size_t _S_buffer_size() _GLIBCXX_NOEXCEPT
00873       { return __deque_buf_size(sizeof(_Tp)); }
00874 
00875       // Functions controlling memory layout, and nothing else.
00876       using _Base::_M_initialize_map;
00877       using _Base::_M_create_nodes;
00878       using _Base::_M_destroy_nodes;
00879       using _Base::_M_allocate_node;
00880       using _Base::_M_deallocate_node;
00881       using _Base::_M_allocate_map;
00882       using _Base::_M_deallocate_map;
00883       using _Base::_M_get_Tp_allocator;
00884 
00885       /**
00886        *  A total of four data members accumulated down the hierarchy.
00887        *  May be accessed via _M_impl.*
00888        */
00889       using _Base::_M_impl;
00890 
00891     public:
00892       // [23.2.1.1] construct/copy/destroy
00893       // (assign() and get_allocator() are also listed in this section)
00894 
00895       /**
00896        *  @brief  Creates a %deque with no elements.
00897        */
00898       deque() : _Base() { }
00899 
00900       /**
00901        *  @brief  Creates a %deque with no elements.
00902        *  @param  __a  An allocator object.
00903        */
00904       explicit
00905       deque(const allocator_type& __a)
00906       : _Base(__a, 0) { }
00907 
00908 #if __cplusplus >= 201103L
00909       /**
00910        *  @brief  Creates a %deque with default constructed elements.
00911        *  @param  __n  The number of elements to initially create.
00912        *  @param  __a  An allocator.
00913        *
00914        *  This constructor fills the %deque with @a n default
00915        *  constructed elements.
00916        */
00917       explicit
00918       deque(size_type __n, const allocator_type& __a = allocator_type())
00919       : _Base(__a, __n)
00920       { _M_default_initialize(); }
00921 
00922       /**
00923        *  @brief  Creates a %deque with copies of an exemplar element.
00924        *  @param  __n  The number of elements to initially create.
00925        *  @param  __value  An element to copy.
00926        *  @param  __a  An allocator.
00927        *
00928        *  This constructor fills the %deque with @a __n copies of @a __value.
00929        */
00930       deque(size_type __n, const value_type& __value,
00931             const allocator_type& __a = allocator_type())
00932       : _Base(__a, __n)
00933       { _M_fill_initialize(__value); }
00934 #else
00935       /**
00936        *  @brief  Creates a %deque with copies of an exemplar element.
00937        *  @param  __n  The number of elements to initially create.
00938        *  @param  __value  An element to copy.
00939        *  @param  __a  An allocator.
00940        *
00941        *  This constructor fills the %deque with @a __n copies of @a __value.
00942        */
00943       explicit
00944       deque(size_type __n, const value_type& __value = value_type(),
00945             const allocator_type& __a = allocator_type())
00946       : _Base(__a, __n)
00947       { _M_fill_initialize(__value); }
00948 #endif
00949 
00950       /**
00951        *  @brief  %Deque copy constructor.
00952        *  @param  __x  A %deque of identical element and allocator types.
00953        *
00954        *  The newly-created %deque uses a copy of the allocator object used
00955        *  by @a __x (unless the allocator traits dictate a different object).
00956        */
00957       deque(const deque& __x)
00958       : _Base(_Alloc_traits::_S_select_on_copy(__x._M_get_Tp_allocator()),
00959               __x.size())
00960       { std::__uninitialized_copy_a(__x.begin(), __x.end(),
00961                                     this->_M_impl._M_start,
00962                                     _M_get_Tp_allocator()); }
00963 
00964 #if __cplusplus >= 201103L
00965       /**
00966        *  @brief  %Deque move constructor.
00967        *  @param  __x  A %deque of identical element and allocator types.
00968        *
00969        *  The newly-created %deque contains the exact contents of @a __x.
00970        *  The contents of @a __x are a valid, but unspecified %deque.
00971        */
00972       deque(deque&& __x)
00973       : _Base(std::move(__x)) { }
00974 
00975       /// Copy constructor with alternative allocator
00976       deque(const deque& __x, const allocator_type& __a)
00977       : _Base(__a, __x.size())
00978       { std::__uninitialized_copy_a(__x.begin(), __x.end(),
00979                                     this->_M_impl._M_start,
00980                                     _M_get_Tp_allocator()); }
00981 
00982       /// Move constructor with alternative allocator
00983       deque(deque&& __x, const allocator_type& __a)
00984       : _Base(std::move(__x), __a, __x.size())
00985       {
00986         if (__x.get_allocator() != __a)
00987           {
00988             std::__uninitialized_move_a(__x.begin(), __x.end(),
00989                                         this->_M_impl._M_start,
00990                                         _M_get_Tp_allocator());
00991             __x.clear();
00992           }
00993       }
00994 
00995       /**
00996        *  @brief  Builds a %deque from an initializer list.
00997        *  @param  __l  An initializer_list.
00998        *  @param  __a  An allocator object.
00999        *
01000        *  Create a %deque consisting of copies of the elements in the
01001        *  initializer_list @a __l.
01002        *
01003        *  This will call the element type's copy constructor N times
01004        *  (where N is __l.size()) and do no memory reallocation.
01005        */
01006       deque(initializer_list<value_type> __l,
01007             const allocator_type& __a = allocator_type())
01008       : _Base(__a)
01009       {
01010         _M_range_initialize(__l.begin(), __l.end(),
01011                             random_access_iterator_tag());
01012       }
01013 #endif
01014 
01015       /**
01016        *  @brief  Builds a %deque from a range.
01017        *  @param  __first  An input iterator.
01018        *  @param  __last  An input iterator.
01019        *  @param  __a  An allocator object.
01020        *
01021        *  Create a %deque consisting of copies of the elements from [__first,
01022        *  __last).
01023        *
01024        *  If the iterators are forward, bidirectional, or random-access, then
01025        *  this will call the elements' copy constructor N times (where N is
01026        *  distance(__first,__last)) and do no memory reallocation.  But if only
01027        *  input iterators are used, then this will do at most 2N calls to the
01028        *  copy constructor, and logN memory reallocations.
01029        */
01030 #if __cplusplus >= 201103L
01031       template<typename _InputIterator,
01032                typename = std::_RequireInputIter<_InputIterator>>
01033         deque(_InputIterator __first, _InputIterator __last,
01034               const allocator_type& __a = allocator_type())
01035         : _Base(__a)
01036         { _M_initialize_dispatch(__first, __last, __false_type()); }
01037 #else
01038       template<typename _InputIterator>
01039         deque(_InputIterator __first, _InputIterator __last,
01040               const allocator_type& __a = allocator_type())
01041         : _Base(__a)
01042         {
01043           // Check whether it's an integral type.  If so, it's not an iterator.
01044           typedef typename std::__is_integer<_InputIterator>::__type _Integral;
01045           _M_initialize_dispatch(__first, __last, _Integral());
01046         }
01047 #endif
01048 
01049       /**
01050        *  The dtor only erases the elements, and note that if the elements
01051        *  themselves are pointers, the pointed-to memory is not touched in any
01052        *  way.  Managing the pointer is the user's responsibility.
01053        */
01054       ~deque()
01055       { _M_destroy_data(begin(), end(), _M_get_Tp_allocator()); }
01056 
01057       /**
01058        *  @brief  %Deque assignment operator.
01059        *  @param  __x  A %deque of identical element and allocator types.
01060        *
01061        *  All the elements of @a x are copied.
01062        *
01063        *  The newly-created %deque uses a copy of the allocator object used
01064        *  by @a __x (unless the allocator traits dictate a different object).
01065        */
01066       deque&
01067       operator=(const deque& __x);
01068 
01069 #if __cplusplus >= 201103L
01070       /**
01071        *  @brief  %Deque move assignment operator.
01072        *  @param  __x  A %deque of identical element and allocator types.
01073        *
01074        *  The contents of @a __x are moved into this deque (without copying,
01075        *  if the allocators permit it).
01076        *  @a __x is a valid, but unspecified %deque.
01077        */
01078       deque&
01079       operator=(deque&& __x) noexcept(_Alloc_traits::_S_always_equal())
01080       {
01081         using __always_equal = typename _Alloc_traits::is_always_equal;
01082         _M_move_assign1(std::move(__x), __always_equal{});
01083         return *this;
01084       }
01085 
01086       /**
01087        *  @brief  Assigns an initializer list to a %deque.
01088        *  @param  __l  An initializer_list.
01089        *
01090        *  This function fills a %deque with copies of the elements in the
01091        *  initializer_list @a __l.
01092        *
01093        *  Note that the assignment completely changes the %deque and that the
01094        *  resulting %deque's size is the same as the number of elements
01095        *  assigned.
01096        */
01097       deque&
01098       operator=(initializer_list<value_type> __l)
01099       {
01100         _M_assign_aux(__l.begin(), __l.end(),
01101                       random_access_iterator_tag());
01102         return *this;
01103       }
01104 #endif
01105 
01106       /**
01107        *  @brief  Assigns a given value to a %deque.
01108        *  @param  __n  Number of elements to be assigned.
01109        *  @param  __val  Value to be assigned.
01110        *
01111        *  This function fills a %deque with @a n copies of the given
01112        *  value.  Note that the assignment completely changes the
01113        *  %deque and that the resulting %deque's size is the same as
01114        *  the number of elements assigned.
01115        */
01116       void
01117       assign(size_type __n, const value_type& __val)
01118       { _M_fill_assign(__n, __val); }
01119 
01120       /**
01121        *  @brief  Assigns a range to a %deque.
01122        *  @param  __first  An input iterator.
01123        *  @param  __last   An input iterator.
01124        *
01125        *  This function fills a %deque with copies of the elements in the
01126        *  range [__first,__last).
01127        *
01128        *  Note that the assignment completely changes the %deque and that the
01129        *  resulting %deque's size is the same as the number of elements
01130        *  assigned.
01131        */
01132 #if __cplusplus >= 201103L
01133       template<typename _InputIterator,
01134                typename = std::_RequireInputIter<_InputIterator>>
01135         void
01136         assign(_InputIterator __first, _InputIterator __last)
01137         { _M_assign_dispatch(__first, __last, __false_type()); }
01138 #else
01139       template<typename _InputIterator>
01140         void
01141         assign(_InputIterator __first, _InputIterator __last)
01142         {
01143           typedef typename std::__is_integer<_InputIterator>::__type _Integral;
01144           _M_assign_dispatch(__first, __last, _Integral());
01145         }
01146 #endif
01147 
01148 #if __cplusplus >= 201103L
01149       /**
01150        *  @brief  Assigns an initializer list to a %deque.
01151        *  @param  __l  An initializer_list.
01152        *
01153        *  This function fills a %deque with copies of the elements in the
01154        *  initializer_list @a __l.
01155        *
01156        *  Note that the assignment completely changes the %deque and that the
01157        *  resulting %deque's size is the same as the number of elements
01158        *  assigned.
01159        */
01160       void
01161       assign(initializer_list<value_type> __l)
01162       { _M_assign_aux(__l.begin(), __l.end(), random_access_iterator_tag()); }
01163 #endif
01164 
01165       /// Get a copy of the memory allocation object.
01166       allocator_type
01167       get_allocator() const _GLIBCXX_NOEXCEPT
01168       { return _Base::get_allocator(); }
01169 
01170       // iterators
01171       /**
01172        *  Returns a read/write iterator that points to the first element in the
01173        *  %deque.  Iteration is done in ordinary element order.
01174        */
01175       iterator
01176       begin() _GLIBCXX_NOEXCEPT
01177       { return this->_M_impl._M_start; }
01178 
01179       /**
01180        *  Returns a read-only (constant) iterator that points to the first
01181        *  element in the %deque.  Iteration is done in ordinary element order.
01182        */
01183       const_iterator
01184       begin() const _GLIBCXX_NOEXCEPT
01185       { return this->_M_impl._M_start; }
01186 
01187       /**
01188        *  Returns a read/write iterator that points one past the last
01189        *  element in the %deque.  Iteration is done in ordinary
01190        *  element order.
01191        */
01192       iterator
01193       end() _GLIBCXX_NOEXCEPT
01194       { return this->_M_impl._M_finish; }
01195 
01196       /**
01197        *  Returns a read-only (constant) iterator that points one past
01198        *  the last element in the %deque.  Iteration is done in
01199        *  ordinary element order.
01200        */
01201       const_iterator
01202       end() const _GLIBCXX_NOEXCEPT
01203       { return this->_M_impl._M_finish; }
01204 
01205       /**
01206        *  Returns a read/write reverse iterator that points to the
01207        *  last element in the %deque.  Iteration is done in reverse
01208        *  element order.
01209        */
01210       reverse_iterator
01211       rbegin() _GLIBCXX_NOEXCEPT
01212       { return reverse_iterator(this->_M_impl._M_finish); }
01213 
01214       /**
01215        *  Returns a read-only (constant) reverse iterator that points
01216        *  to the last element in the %deque.  Iteration is done in
01217        *  reverse element order.
01218        */
01219       const_reverse_iterator
01220       rbegin() const _GLIBCXX_NOEXCEPT
01221       { return const_reverse_iterator(this->_M_impl._M_finish); }
01222 
01223       /**
01224        *  Returns a read/write reverse iterator that points to one
01225        *  before the first element in the %deque.  Iteration is done
01226        *  in reverse element order.
01227        */
01228       reverse_iterator
01229       rend() _GLIBCXX_NOEXCEPT
01230       { return reverse_iterator(this->_M_impl._M_start); }
01231 
01232       /**
01233        *  Returns a read-only (constant) reverse iterator that points
01234        *  to one before the first element in the %deque.  Iteration is
01235        *  done in reverse element order.
01236        */
01237       const_reverse_iterator
01238       rend() const _GLIBCXX_NOEXCEPT
01239       { return const_reverse_iterator(this->_M_impl._M_start); }
01240 
01241 #if __cplusplus >= 201103L
01242       /**
01243        *  Returns a read-only (constant) iterator that points to the first
01244        *  element in the %deque.  Iteration is done in ordinary element order.
01245        */
01246       const_iterator
01247       cbegin() const noexcept
01248       { return this->_M_impl._M_start; }
01249 
01250       /**
01251        *  Returns a read-only (constant) iterator that points one past
01252        *  the last element in the %deque.  Iteration is done in
01253        *  ordinary element order.
01254        */
01255       const_iterator
01256       cend() const noexcept
01257       { return this->_M_impl._M_finish; }
01258 
01259       /**
01260        *  Returns a read-only (constant) reverse iterator that points
01261        *  to the last element in the %deque.  Iteration is done in
01262        *  reverse element order.
01263        */
01264       const_reverse_iterator
01265       crbegin() const noexcept
01266       { return const_reverse_iterator(this->_M_impl._M_finish); }
01267 
01268       /**
01269        *  Returns a read-only (constant) reverse iterator that points
01270        *  to one before the first element in the %deque.  Iteration is
01271        *  done in reverse element order.
01272        */
01273       const_reverse_iterator
01274       crend() const noexcept
01275       { return const_reverse_iterator(this->_M_impl._M_start); }
01276 #endif
01277 
01278       // [23.2.1.2] capacity
01279       /**  Returns the number of elements in the %deque.  */
01280       size_type
01281       size() const _GLIBCXX_NOEXCEPT
01282       { return this->_M_impl._M_finish - this->_M_impl._M_start; }
01283 
01284       /**  Returns the size() of the largest possible %deque.  */
01285       size_type
01286       max_size() const _GLIBCXX_NOEXCEPT
01287       { return _Alloc_traits::max_size(_M_get_Tp_allocator()); }
01288 
01289 #if __cplusplus >= 201103L
01290       /**
01291        *  @brief  Resizes the %deque to the specified number of elements.
01292        *  @param  __new_size  Number of elements the %deque should contain.
01293        *
01294        *  This function will %resize the %deque to the specified
01295        *  number of elements.  If the number is smaller than the
01296        *  %deque's current size the %deque is truncated, otherwise
01297        *  default constructed elements are appended.
01298        */
01299       void
01300       resize(size_type __new_size)
01301       {
01302         const size_type __len = size();
01303         if (__new_size > __len)
01304           _M_default_append(__new_size - __len);
01305         else if (__new_size < __len)
01306           _M_erase_at_end(this->_M_impl._M_start
01307                           + difference_type(__new_size));
01308       }
01309 
01310       /**
01311        *  @brief  Resizes the %deque to the specified number of elements.
01312        *  @param  __new_size  Number of elements the %deque should contain.
01313        *  @param  __x  Data with which new elements should be populated.
01314        *
01315        *  This function will %resize the %deque to the specified
01316        *  number of elements.  If the number is smaller than the
01317        *  %deque's current size the %deque is truncated, otherwise the
01318        *  %deque is extended and new elements are populated with given
01319        *  data.
01320        */
01321       void
01322       resize(size_type __new_size, const value_type& __x)
01323       {
01324         const size_type __len = size();
01325         if (__new_size > __len)
01326           _M_fill_insert(this->_M_impl._M_finish, __new_size - __len, __x);
01327         else if (__new_size < __len)
01328           _M_erase_at_end(this->_M_impl._M_start
01329                           + difference_type(__new_size));
01330       }
01331 #else
01332       /**
01333        *  @brief  Resizes the %deque to the specified number of elements.
01334        *  @param  __new_size  Number of elements the %deque should contain.
01335        *  @param  __x  Data with which new elements should be populated.
01336        *
01337        *  This function will %resize the %deque to the specified
01338        *  number of elements.  If the number is smaller than the
01339        *  %deque's current size the %deque is truncated, otherwise the
01340        *  %deque is extended and new elements are populated with given
01341        *  data.
01342        */
01343       void
01344       resize(size_type __new_size, value_type __x = value_type())
01345       {
01346         const size_type __len = size();
01347         if (__new_size > __len)
01348           _M_fill_insert(this->_M_impl._M_finish, __new_size - __len, __x);
01349         else if (__new_size < __len)
01350           _M_erase_at_end(this->_M_impl._M_start
01351                           + difference_type(__new_size));
01352       }
01353 #endif
01354 
01355 #if __cplusplus >= 201103L
01356       /**  A non-binding request to reduce memory use.  */
01357       void
01358       shrink_to_fit() noexcept
01359       { _M_shrink_to_fit(); }
01360 #endif
01361 
01362       /**
01363        *  Returns true if the %deque is empty.  (Thus begin() would
01364        *  equal end().)
01365        */
01366       bool
01367       empty() const _GLIBCXX_NOEXCEPT
01368       { return this->_M_impl._M_finish == this->_M_impl._M_start; }
01369 
01370       // element access
01371       /**
01372        *  @brief Subscript access to the data contained in the %deque.
01373        *  @param __n The index of the element for which data should be
01374        *  accessed.
01375        *  @return  Read/write reference to data.
01376        *
01377        *  This operator allows for easy, array-style, data access.
01378        *  Note that data access with this operator is unchecked and
01379        *  out_of_range lookups are not defined. (For checked lookups
01380        *  see at().)
01381        */
01382       reference
01383       operator[](size_type __n) _GLIBCXX_NOEXCEPT
01384       {
01385         __glibcxx_requires_subscript(__n);
01386         return this->_M_impl._M_start[difference_type(__n)];
01387       }
01388 
01389       /**
01390        *  @brief Subscript access to the data contained in the %deque.
01391        *  @param __n The index of the element for which data should be
01392        *  accessed.
01393        *  @return  Read-only (constant) reference to data.
01394        *
01395        *  This operator allows for easy, array-style, data access.
01396        *  Note that data access with this operator is unchecked and
01397        *  out_of_range lookups are not defined. (For checked lookups
01398        *  see at().)
01399        */
01400       const_reference
01401       operator[](size_type __n) const _GLIBCXX_NOEXCEPT
01402       {
01403         __glibcxx_requires_subscript(__n);
01404         return this->_M_impl._M_start[difference_type(__n)];
01405       }
01406 
01407     protected:
01408       /// Safety check used only from at().
01409       void
01410       _M_range_check(size_type __n) const
01411       {
01412         if (__n >= this->size())
01413           __throw_out_of_range_fmt(__N("deque::_M_range_check: __n "
01414                                        "(which is %zu)>= this->size() "
01415                                        "(which is %zu)"),
01416                                    __n, this->size());
01417       }
01418 
01419     public:
01420       /**
01421        *  @brief  Provides access to the data contained in the %deque.
01422        *  @param __n The index of the element for which data should be
01423        *  accessed.
01424        *  @return  Read/write reference to data.
01425        *  @throw  std::out_of_range  If @a __n is an invalid index.
01426        *
01427        *  This function provides for safer data access.  The parameter
01428        *  is first checked that it is in the range of the deque.  The
01429        *  function throws out_of_range if the check fails.
01430        */
01431       reference
01432       at(size_type __n)
01433       {
01434         _M_range_check(__n);
01435         return (*this)[__n];
01436       }
01437 
01438       /**
01439        *  @brief  Provides access to the data contained in the %deque.
01440        *  @param __n The index of the element for which data should be
01441        *  accessed.
01442        *  @return  Read-only (constant) reference to data.
01443        *  @throw  std::out_of_range  If @a __n is an invalid index.
01444        *
01445        *  This function provides for safer data access.  The parameter is first
01446        *  checked that it is in the range of the deque.  The function throws
01447        *  out_of_range if the check fails.
01448        */
01449       const_reference
01450       at(size_type __n) const
01451       {
01452         _M_range_check(__n);
01453         return (*this)[__n];
01454       }
01455 
01456       /**
01457        *  Returns a read/write reference to the data at the first
01458        *  element of the %deque.
01459        */
01460       reference
01461       front() _GLIBCXX_NOEXCEPT
01462       {
01463         __glibcxx_requires_nonempty();
01464         return *begin();
01465       }
01466 
01467       /**
01468        *  Returns a read-only (constant) reference to the data at the first
01469        *  element of the %deque.
01470        */
01471       const_reference
01472       front() const _GLIBCXX_NOEXCEPT
01473       {
01474         __glibcxx_requires_nonempty();
01475         return *begin();
01476       }
01477 
01478       /**
01479        *  Returns a read/write reference to the data at the last element of the
01480        *  %deque.
01481        */
01482       reference
01483       back() _GLIBCXX_NOEXCEPT
01484       {
01485         __glibcxx_requires_nonempty();
01486         iterator __tmp = end();
01487         --__tmp;
01488         return *__tmp;
01489       }
01490 
01491       /**
01492        *  Returns a read-only (constant) reference to the data at the last
01493        *  element of the %deque.
01494        */
01495       const_reference
01496       back() const _GLIBCXX_NOEXCEPT
01497       {
01498         __glibcxx_requires_nonempty();
01499         const_iterator __tmp = end();
01500         --__tmp;
01501         return *__tmp;
01502       }
01503 
01504       // [23.2.1.2] modifiers
01505       /**
01506        *  @brief  Add data to the front of the %deque.
01507        *  @param  __x  Data to be added.
01508        *
01509        *  This is a typical stack operation.  The function creates an
01510        *  element at the front of the %deque and assigns the given
01511        *  data to it.  Due to the nature of a %deque this operation
01512        *  can be done in constant time.
01513        */
01514       void
01515       push_front(const value_type& __x)
01516       {
01517         if (this->_M_impl._M_start._M_cur != this->_M_impl._M_start._M_first)
01518           {
01519             _Alloc_traits::construct(this->_M_impl,
01520                                      this->_M_impl._M_start._M_cur - 1,
01521                                      __x);
01522             --this->_M_impl._M_start._M_cur;
01523           }
01524         else
01525           _M_push_front_aux(__x);
01526       }
01527 
01528 #if __cplusplus >= 201103L
01529       void
01530       push_front(value_type&& __x)
01531       { emplace_front(std::move(__x)); }
01532 
01533       template<typename... _Args>
01534 #if __cplusplus > 201402L
01535         reference
01536 #else
01537         void
01538 #endif
01539         emplace_front(_Args&&... __args);
01540 #endif
01541 
01542       /**
01543        *  @brief  Add data to the end of the %deque.
01544        *  @param  __x  Data to be added.
01545        *
01546        *  This is a typical stack operation.  The function creates an
01547        *  element at the end of the %deque and assigns the given data
01548        *  to it.  Due to the nature of a %deque this operation can be
01549        *  done in constant time.
01550        */
01551       void
01552       push_back(const value_type& __x)
01553       {
01554         if (this->_M_impl._M_finish._M_cur
01555             != this->_M_impl._M_finish._M_last - 1)
01556           {
01557             _Alloc_traits::construct(this->_M_impl,
01558                                      this->_M_impl._M_finish._M_cur, __x);
01559             ++this->_M_impl._M_finish._M_cur;
01560           }
01561         else
01562           _M_push_back_aux(__x);
01563       }
01564 
01565 #if __cplusplus >= 201103L
01566       void
01567       push_back(value_type&& __x)
01568       { emplace_back(std::move(__x)); }
01569 
01570       template<typename... _Args>
01571 #if __cplusplus > 201402L
01572         reference
01573 #else
01574         void
01575 #endif
01576         emplace_back(_Args&&... __args);
01577 #endif
01578 
01579       /**
01580        *  @brief  Removes first element.
01581        *
01582        *  This is a typical stack operation.  It shrinks the %deque by one.
01583        *
01584        *  Note that no data is returned, and if the first element's data is
01585        *  needed, it should be retrieved before pop_front() is called.
01586        */
01587       void
01588       pop_front() _GLIBCXX_NOEXCEPT
01589       {
01590         __glibcxx_requires_nonempty();
01591         if (this->_M_impl._M_start._M_cur
01592             != this->_M_impl._M_start._M_last - 1)
01593           {
01594             _Alloc_traits::destroy(this->_M_impl,
01595                                    this->_M_impl._M_start._M_cur);
01596             ++this->_M_impl._M_start._M_cur;
01597           }
01598         else
01599           _M_pop_front_aux();
01600       }
01601 
01602       /**
01603        *  @brief  Removes last element.
01604        *
01605        *  This is a typical stack operation.  It shrinks the %deque by one.
01606        *
01607        *  Note that no data is returned, and if the last element's data is
01608        *  needed, it should be retrieved before pop_back() is called.
01609        */
01610       void
01611       pop_back() _GLIBCXX_NOEXCEPT
01612       {
01613         __glibcxx_requires_nonempty();
01614         if (this->_M_impl._M_finish._M_cur
01615             != this->_M_impl._M_finish._M_first)
01616           {
01617             --this->_M_impl._M_finish._M_cur;
01618             _Alloc_traits::destroy(this->_M_impl,
01619                                    this->_M_impl._M_finish._M_cur);
01620           }
01621         else
01622           _M_pop_back_aux();
01623       }
01624 
01625 #if __cplusplus >= 201103L
01626       /**
01627        *  @brief  Inserts an object in %deque before specified iterator.
01628        *  @param  __position  A const_iterator into the %deque.
01629        *  @param  __args  Arguments.
01630        *  @return  An iterator that points to the inserted data.
01631        *
01632        *  This function will insert an object of type T constructed
01633        *  with T(std::forward<Args>(args)...) before the specified location.
01634        */
01635       template<typename... _Args>
01636         iterator
01637         emplace(const_iterator __position, _Args&&... __args);
01638 
01639       /**
01640        *  @brief  Inserts given value into %deque before specified iterator.
01641        *  @param  __position  A const_iterator into the %deque.
01642        *  @param  __x  Data to be inserted.
01643        *  @return  An iterator that points to the inserted data.
01644        *
01645        *  This function will insert a copy of the given value before the
01646        *  specified location.
01647        */
01648       iterator
01649       insert(const_iterator __position, const value_type& __x);
01650 #else
01651       /**
01652        *  @brief  Inserts given value into %deque before specified iterator.
01653        *  @param  __position  An iterator into the %deque.
01654        *  @param  __x  Data to be inserted.
01655        *  @return  An iterator that points to the inserted data.
01656        *
01657        *  This function will insert a copy of the given value before the
01658        *  specified location.
01659        */
01660       iterator
01661       insert(iterator __position, const value_type& __x);
01662 #endif
01663 
01664 #if __cplusplus >= 201103L
01665       /**
01666        *  @brief  Inserts given rvalue into %deque before specified iterator.
01667        *  @param  __position  A const_iterator into the %deque.
01668        *  @param  __x  Data to be inserted.
01669        *  @return  An iterator that points to the inserted data.
01670        *
01671        *  This function will insert a copy of the given rvalue before the
01672        *  specified location.
01673        */
01674       iterator
01675       insert(const_iterator __position, value_type&& __x)
01676       { return emplace(__position, std::move(__x)); }
01677 
01678       /**
01679        *  @brief  Inserts an initializer list into the %deque.
01680        *  @param  __p  An iterator into the %deque.
01681        *  @param  __l  An initializer_list.
01682        *
01683        *  This function will insert copies of the data in the
01684        *  initializer_list @a __l into the %deque before the location
01685        *  specified by @a __p.  This is known as <em>list insert</em>.
01686        */
01687       iterator
01688       insert(const_iterator __p, initializer_list<value_type> __l)
01689       {
01690         auto __offset = __p - cbegin();
01691         _M_range_insert_aux(__p._M_const_cast(), __l.begin(), __l.end(),
01692                             std::random_access_iterator_tag());
01693         return begin() + __offset;
01694       }
01695 #endif
01696 
01697 #if __cplusplus >= 201103L
01698       /**
01699        *  @brief  Inserts a number of copies of given data into the %deque.
01700        *  @param  __position  A const_iterator into the %deque.
01701        *  @param  __n  Number of elements to be inserted.
01702        *  @param  __x  Data to be inserted.
01703        *  @return  An iterator that points to the inserted data.
01704        *
01705        *  This function will insert a specified number of copies of the given
01706        *  data before the location specified by @a __position.
01707        */
01708       iterator
01709       insert(const_iterator __position, size_type __n, const value_type& __x)
01710       {
01711         difference_type __offset = __position - cbegin();
01712         _M_fill_insert(__position._M_const_cast(), __n, __x);
01713         return begin() + __offset;
01714       }
01715 #else
01716       /**
01717        *  @brief  Inserts a number of copies of given data into the %deque.
01718        *  @param  __position  An iterator into the %deque.
01719        *  @param  __n  Number of elements to be inserted.
01720        *  @param  __x  Data to be inserted.
01721        *
01722        *  This function will insert a specified number of copies of the given
01723        *  data before the location specified by @a __position.
01724        */
01725       void
01726       insert(iterator __position, size_type __n, const value_type& __x)
01727       { _M_fill_insert(__position, __n, __x); }
01728 #endif
01729 
01730 #if __cplusplus >= 201103L
01731       /**
01732        *  @brief  Inserts a range into the %deque.
01733        *  @param  __position  A const_iterator into the %deque.
01734        *  @param  __first  An input iterator.
01735        *  @param  __last   An input iterator.
01736        *  @return  An iterator that points to the inserted data.
01737        *
01738        *  This function will insert copies of the data in the range
01739        *  [__first,__last) into the %deque before the location specified
01740        *  by @a __position.  This is known as <em>range insert</em>.
01741        */
01742       template<typename _InputIterator,
01743                typename = std::_RequireInputIter<_InputIterator>>
01744         iterator
01745         insert(const_iterator __position, _InputIterator __first,
01746                _InputIterator __last)
01747         {
01748           difference_type __offset = __position - cbegin();
01749           _M_insert_dispatch(__position._M_const_cast(),
01750                              __first, __last, __false_type());
01751           return begin() + __offset;
01752         }
01753 #else
01754       /**
01755        *  @brief  Inserts a range into the %deque.
01756        *  @param  __position  An iterator into the %deque.
01757        *  @param  __first  An input iterator.
01758        *  @param  __last   An input iterator.
01759        *
01760        *  This function will insert copies of the data in the range
01761        *  [__first,__last) into the %deque before the location specified
01762        *  by @a __position.  This is known as <em>range insert</em>.
01763        */
01764       template<typename _InputIterator>
01765         void
01766         insert(iterator __position, _InputIterator __first,
01767                _InputIterator __last)
01768         {
01769           // Check whether it's an integral type.  If so, it's not an iterator.
01770           typedef typename std::__is_integer<_InputIterator>::__type _Integral;
01771           _M_insert_dispatch(__position, __first, __last, _Integral());
01772         }
01773 #endif
01774 
01775       /**
01776        *  @brief  Remove element at given position.
01777        *  @param  __position  Iterator pointing to element to be erased.
01778        *  @return  An iterator pointing to the next element (or end()).
01779        *
01780        *  This function will erase the element at the given position and thus
01781        *  shorten the %deque by one.
01782        *
01783        *  The user is cautioned that
01784        *  this function only erases the element, and that if the element is
01785        *  itself a pointer, the pointed-to memory is not touched in any way.
01786        *  Managing the pointer is the user's responsibility.
01787        */
01788       iterator
01789 #if __cplusplus >= 201103L
01790       erase(const_iterator __position)
01791 #else
01792       erase(iterator __position)
01793 #endif
01794       { return _M_erase(__position._M_const_cast()); }
01795 
01796       /**
01797        *  @brief  Remove a range of elements.
01798        *  @param  __first  Iterator pointing to the first element to be erased.
01799        *  @param  __last  Iterator pointing to one past the last element to be
01800        *                erased.
01801        *  @return  An iterator pointing to the element pointed to by @a last
01802        *           prior to erasing (or end()).
01803        *
01804        *  This function will erase the elements in the range
01805        *  [__first,__last) and shorten the %deque accordingly.
01806        *
01807        *  The user is cautioned that
01808        *  this function only erases the elements, and that if the elements
01809        *  themselves are pointers, the pointed-to memory is not touched in any
01810        *  way.  Managing the pointer is the user's responsibility.
01811        */
01812       iterator
01813 #if __cplusplus >= 201103L
01814       erase(const_iterator __first, const_iterator __last)
01815 #else
01816       erase(iterator __first, iterator __last)
01817 #endif
01818       { return _M_erase(__first._M_const_cast(), __last._M_const_cast()); }
01819 
01820       /**
01821        *  @brief  Swaps data with another %deque.
01822        *  @param  __x  A %deque of the same element and allocator types.
01823        *
01824        *  This exchanges the elements between two deques in constant time.
01825        *  (Four pointers, so it should be quite fast.)
01826        *  Note that the global std::swap() function is specialized such that
01827        *  std::swap(d1,d2) will feed to this function.
01828        *
01829        *  Whether the allocators are swapped depends on the allocator traits.
01830        */
01831       void
01832       swap(deque& __x) _GLIBCXX_NOEXCEPT
01833       {
01834 #if __cplusplus >= 201103L
01835         __glibcxx_assert(_Alloc_traits::propagate_on_container_swap::value
01836                          || _M_get_Tp_allocator() == __x._M_get_Tp_allocator());
01837 #endif
01838         _M_impl._M_swap_data(__x._M_impl);
01839         _Alloc_traits::_S_on_swap(_M_get_Tp_allocator(),
01840                                   __x._M_get_Tp_allocator());
01841       }
01842 
01843       /**
01844        *  Erases all the elements.  Note that this function only erases the
01845        *  elements, and that if the elements themselves are pointers, the
01846        *  pointed-to memory is not touched in any way.  Managing the pointer is
01847        *  the user's responsibility.
01848        */
01849       void
01850       clear() _GLIBCXX_NOEXCEPT
01851       { _M_erase_at_end(begin()); }
01852 
01853     protected:
01854       // Internal constructor functions follow.
01855 
01856       // called by the range constructor to implement [23.1.1]/9
01857 
01858       // _GLIBCXX_RESOLVE_LIB_DEFECTS
01859       // 438. Ambiguity in the "do the right thing" clause
01860       template<typename _Integer>
01861         void
01862         _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type)
01863         {
01864           _M_initialize_map(static_cast<size_type>(__n));
01865           _M_fill_initialize(__x);
01866         }
01867 
01868       // called by the range constructor to implement [23.1.1]/9
01869       template<typename _InputIterator>
01870         void
01871         _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
01872                                __false_type)
01873         {
01874           _M_range_initialize(__first, __last,
01875                               std::__iterator_category(__first));
01876         }
01877 
01878       // called by the second initialize_dispatch above
01879       //@{
01880       /**
01881        *  @brief Fills the deque with whatever is in [first,last).
01882        *  @param  __first  An input iterator.
01883        *  @param  __last  An input iterator.
01884        *  @return   Nothing.
01885        *
01886        *  If the iterators are actually forward iterators (or better), then the
01887        *  memory layout can be done all at once.  Else we move forward using
01888        *  push_back on each value from the iterator.
01889        */
01890       template<typename _InputIterator>
01891         void
01892         _M_range_initialize(_InputIterator __first, _InputIterator __last,
01893                             std::input_iterator_tag);
01894 
01895       // called by the second initialize_dispatch above
01896       template<typename _ForwardIterator>
01897         void
01898         _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last,
01899                             std::forward_iterator_tag);
01900       //@}
01901 
01902       /**
01903        *  @brief Fills the %deque with copies of value.
01904        *  @param  __value  Initial value.
01905        *  @return   Nothing.
01906        *  @pre _M_start and _M_finish have already been initialized,
01907        *  but none of the %deque's elements have yet been constructed.
01908        *
01909        *  This function is called only when the user provides an explicit size
01910        *  (with or without an explicit exemplar value).
01911        */
01912       void
01913       _M_fill_initialize(const value_type& __value);
01914 
01915 #if __cplusplus >= 201103L
01916       // called by deque(n).
01917       void
01918       _M_default_initialize();
01919 #endif
01920 
01921       // Internal assign functions follow.  The *_aux functions do the actual
01922       // assignment work for the range versions.
01923 
01924       // called by the range assign to implement [23.1.1]/9
01925 
01926       // _GLIBCXX_RESOLVE_LIB_DEFECTS
01927       // 438. Ambiguity in the "do the right thing" clause
01928       template<typename _Integer>
01929         void
01930         _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
01931         { _M_fill_assign(__n, __val); }
01932 
01933       // called by the range assign to implement [23.1.1]/9
01934       template<typename _InputIterator>
01935         void
01936         _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
01937                            __false_type)
01938         { _M_assign_aux(__first, __last, std::__iterator_category(__first)); }
01939 
01940       // called by the second assign_dispatch above
01941       template<typename _InputIterator>
01942         void
01943         _M_assign_aux(_InputIterator __first, _InputIterator __last,
01944                       std::input_iterator_tag);
01945 
01946       // called by the second assign_dispatch above
01947       template<typename _ForwardIterator>
01948         void
01949         _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,
01950                       std::forward_iterator_tag)
01951         {
01952           const size_type __len = std::distance(__first, __last);
01953           if (__len > size())
01954             {
01955               _ForwardIterator __mid = __first;
01956               std::advance(__mid, size());
01957               std::copy(__first, __mid, begin());
01958               _M_range_insert_aux(end(), __mid, __last,
01959                                   std::__iterator_category(__first));
01960             }
01961           else
01962             _M_erase_at_end(std::copy(__first, __last, begin()));
01963         }
01964 
01965       // Called by assign(n,t), and the range assign when it turns out
01966       // to be the same thing.
01967       void
01968       _M_fill_assign(size_type __n, const value_type& __val)
01969       {
01970         if (__n > size())
01971           {
01972             std::fill(begin(), end(), __val);
01973             _M_fill_insert(end(), __n - size(), __val);
01974           }
01975         else
01976           {
01977             _M_erase_at_end(begin() + difference_type(__n));
01978             std::fill(begin(), end(), __val);
01979           }
01980       }
01981 
01982       //@{
01983       /// Helper functions for push_* and pop_*.
01984 #if __cplusplus < 201103L
01985       void _M_push_back_aux(const value_type&);
01986 
01987       void _M_push_front_aux(const value_type&);
01988 #else
01989       template<typename... _Args>
01990         void _M_push_back_aux(_Args&&... __args);
01991 
01992       template<typename... _Args>
01993         void _M_push_front_aux(_Args&&... __args);
01994 #endif
01995 
01996       void _M_pop_back_aux();
01997 
01998       void _M_pop_front_aux();
01999       //@}
02000 
02001       // Internal insert functions follow.  The *_aux functions do the actual
02002       // insertion work when all shortcuts fail.
02003 
02004       // called by the range insert to implement [23.1.1]/9
02005 
02006       // _GLIBCXX_RESOLVE_LIB_DEFECTS
02007       // 438. Ambiguity in the "do the right thing" clause
02008       template<typename _Integer>
02009         void
02010         _M_insert_dispatch(iterator __pos,
02011                            _Integer __n, _Integer __x, __true_type)
02012         { _M_fill_insert(__pos, __n, __x); }
02013 
02014       // called by the range insert to implement [23.1.1]/9
02015       template<typename _InputIterator>
02016         void
02017         _M_insert_dispatch(iterator __pos,
02018                            _InputIterator __first, _InputIterator __last,
02019                            __false_type)
02020         {
02021           _M_range_insert_aux(__pos, __first, __last,
02022                               std::__iterator_category(__first));
02023         }
02024 
02025       // called by the second insert_dispatch above
02026       template<typename _InputIterator>
02027         void
02028         _M_range_insert_aux(iterator __pos, _InputIterator __first,
02029                             _InputIterator __last, std::input_iterator_tag);
02030 
02031       // called by the second insert_dispatch above
02032       template<typename _ForwardIterator>
02033         void
02034         _M_range_insert_aux(iterator __pos, _ForwardIterator __first,
02035                             _ForwardIterator __last, std::forward_iterator_tag);
02036 
02037       // Called by insert(p,n,x), and the range insert when it turns out to be
02038       // the same thing.  Can use fill functions in optimal situations,
02039       // otherwise passes off to insert_aux(p,n,x).
02040       void
02041       _M_fill_insert(iterator __pos, size_type __n, const value_type& __x);
02042 
02043       // called by insert(p,x)
02044 #if __cplusplus < 201103L
02045       iterator
02046       _M_insert_aux(iterator __pos, const value_type& __x);
02047 #else
02048       template<typename... _Args>
02049         iterator
02050         _M_insert_aux(iterator __pos, _Args&&... __args);
02051 #endif
02052 
02053       // called by insert(p,n,x) via fill_insert
02054       void
02055       _M_insert_aux(iterator __pos, size_type __n, const value_type& __x);
02056 
02057       // called by range_insert_aux for forward iterators
02058       template<typename _ForwardIterator>
02059         void
02060         _M_insert_aux(iterator __pos,
02061                       _ForwardIterator __first, _ForwardIterator __last,
02062                       size_type __n);
02063 
02064 
02065       // Internal erase functions follow.
02066 
02067       void
02068       _M_destroy_data_aux(iterator __first, iterator __last);
02069 
02070       // Called by ~deque().
02071       // NB: Doesn't deallocate the nodes.
02072       template<typename _Alloc1>
02073         void
02074         _M_destroy_data(iterator __first, iterator __last, const _Alloc1&)
02075         { _M_destroy_data_aux(__first, __last); }
02076 
02077       void
02078       _M_destroy_data(iterator __first, iterator __last,
02079                       const std::allocator<_Tp>&)
02080       {
02081         if (!__has_trivial_destructor(value_type))
02082           _M_destroy_data_aux(__first, __last);
02083       }
02084 
02085       // Called by erase(q1, q2).
02086       void
02087       _M_erase_at_begin(iterator __pos)
02088       {
02089         _M_destroy_data(begin(), __pos, _M_get_Tp_allocator());
02090         _M_destroy_nodes(this->_M_impl._M_start._M_node, __pos._M_node);
02091         this->_M_impl._M_start = __pos;
02092       }
02093 
02094       // Called by erase(q1, q2), resize(), clear(), _M_assign_aux,
02095       // _M_fill_assign, operator=.
02096       void
02097       _M_erase_at_end(iterator __pos)
02098       {
02099         _M_destroy_data(__pos, end(), _M_get_Tp_allocator());
02100         _M_destroy_nodes(__pos._M_node + 1,
02101                          this->_M_impl._M_finish._M_node + 1);
02102         this->_M_impl._M_finish = __pos;
02103       }
02104 
02105       iterator
02106       _M_erase(iterator __pos);
02107 
02108       iterator
02109       _M_erase(iterator __first, iterator __last);
02110 
02111 #if __cplusplus >= 201103L
02112       // Called by resize(sz).
02113       void
02114       _M_default_append(size_type __n);
02115 
02116       bool
02117       _M_shrink_to_fit();
02118 #endif
02119 
02120       //@{
02121       /// Memory-handling helpers for the previous internal insert functions.
02122       iterator
02123       _M_reserve_elements_at_front(size_type __n)
02124       {
02125         const size_type __vacancies = this->_M_impl._M_start._M_cur
02126                                       - this->_M_impl._M_start._M_first;
02127         if (__n > __vacancies)
02128           _M_new_elements_at_front(__n - __vacancies);
02129         return this->_M_impl._M_start - difference_type(__n);
02130       }
02131 
02132       iterator
02133       _M_reserve_elements_at_back(size_type __n)
02134       {
02135         const size_type __vacancies = (this->_M_impl._M_finish._M_last
02136                                        - this->_M_impl._M_finish._M_cur) - 1;
02137         if (__n > __vacancies)
02138           _M_new_elements_at_back(__n - __vacancies);
02139         return this->_M_impl._M_finish + difference_type(__n);
02140       }
02141 
02142       void
02143       _M_new_elements_at_front(size_type __new_elements);
02144 
02145       void
02146       _M_new_elements_at_back(size_type __new_elements);
02147       //@}
02148 
02149 
02150       //@{
02151       /**
02152        *  @brief Memory-handling helpers for the major %map.
02153        *
02154        *  Makes sure the _M_map has space for new nodes.  Does not
02155        *  actually add the nodes.  Can invalidate _M_map pointers.
02156        *  (And consequently, %deque iterators.)
02157        */
02158       void
02159       _M_reserve_map_at_back(size_type __nodes_to_add = 1)
02160       {
02161         if (__nodes_to_add + 1 > this->_M_impl._M_map_size
02162             - (this->_M_impl._M_finish._M_node - this->_M_impl._M_map))
02163           _M_reallocate_map(__nodes_to_add, false);
02164       }
02165 
02166       void
02167       _M_reserve_map_at_front(size_type __nodes_to_add = 1)
02168       {
02169         if (__nodes_to_add > size_type(this->_M_impl._M_start._M_node
02170                                        - this->_M_impl._M_map))
02171           _M_reallocate_map(__nodes_to_add, true);
02172       }
02173 
02174       void
02175       _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front);
02176       //@}
02177 
02178 #if __cplusplus >= 201103L
02179       // Constant-time, nothrow move assignment when source object's memory
02180       // can be moved because the allocators are equal.
02181       void
02182       _M_move_assign1(deque&& __x, /* always equal: */ true_type) noexcept
02183       {
02184         this->_M_impl._M_swap_data(__x._M_impl);
02185         __x.clear();
02186         std::__alloc_on_move(_M_get_Tp_allocator(), __x._M_get_Tp_allocator());
02187       }
02188 
02189       // When the allocators are not equal the operation could throw, because
02190       // we might need to allocate a new map for __x after moving from it
02191       // or we might need to allocate new elements for *this.
02192       void
02193       _M_move_assign1(deque&& __x, /* always equal: */ false_type)
02194       {
02195         constexpr bool __move_storage =
02196           _Alloc_traits::_S_propagate_on_move_assign();
02197         _M_move_assign2(std::move(__x), __bool_constant<__move_storage>());
02198       }
02199 
02200       // Destroy all elements and deallocate all memory, then replace
02201       // with elements created from __args.
02202       template<typename... _Args>
02203       void
02204       _M_replace_map(_Args&&... __args)
02205       {
02206         // Create new data first, so if allocation fails there are no effects.
02207         deque __newobj(std::forward<_Args>(__args)...);
02208         // Free existing storage using existing allocator.
02209         clear();
02210         _M_deallocate_node(*begin()._M_node); // one node left after clear()
02211         _M_deallocate_map(this->_M_impl._M_map, this->_M_impl._M_map_size);
02212         this->_M_impl._M_map = nullptr;
02213         this->_M_impl._M_map_size = 0;
02214         // Take ownership of replacement memory.
02215         this->_M_impl._M_swap_data(__newobj._M_impl);
02216       }
02217 
02218       // Do move assignment when the allocator propagates.
02219       void
02220       _M_move_assign2(deque&& __x, /* propagate: */ true_type)
02221       {
02222         // Make a copy of the original allocator state.
02223         auto __alloc = __x._M_get_Tp_allocator();
02224         // The allocator propagates so storage can be moved from __x,
02225         // leaving __x in a valid empty state with a moved-from allocator.
02226         _M_replace_map(std::move(__x));
02227         // Move the corresponding allocator state too.
02228         _M_get_Tp_allocator() = std::move(__alloc);
02229       }
02230 
02231       // Do move assignment when it may not be possible to move source
02232       // object's memory, resulting in a linear-time operation.
02233       void
02234       _M_move_assign2(deque&& __x, /* propagate: */ false_type)
02235       {
02236         if (__x._M_get_Tp_allocator() == this->_M_get_Tp_allocator())
02237           {
02238             // The allocators are equal so storage can be moved from __x,
02239             // leaving __x in a valid empty state with its current allocator.
02240             _M_replace_map(std::move(__x), __x.get_allocator());
02241           }
02242         else
02243           {
02244             // The rvalue's allocator cannot be moved and is not equal,
02245             // so we need to individually move each element.
02246             _M_assign_aux(std::__make_move_if_noexcept_iterator(__x.begin()),
02247                           std::__make_move_if_noexcept_iterator(__x.end()),
02248                           std::random_access_iterator_tag());
02249             __x.clear();
02250           }
02251       }
02252 #endif
02253     };
02254 
02255 #if __cpp_deduction_guides >= 201606
02256   template<typename _InputIterator, typename _ValT
02257              = typename iterator_traits<_InputIterator>::value_type,
02258            typename _Allocator = allocator<_ValT>,
02259            typename = _RequireInputIter<_InputIterator>,
02260            typename = _RequireAllocator<_Allocator>>
02261     deque(_InputIterator, _InputIterator, _Allocator = _Allocator())
02262       -> deque<_ValT, _Allocator>;
02263 #endif
02264 
02265   /**
02266    *  @brief  Deque equality comparison.
02267    *  @param  __x  A %deque.
02268    *  @param  __y  A %deque of the same type as @a __x.
02269    *  @return  True iff the size and elements of the deques are equal.
02270    *
02271    *  This is an equivalence relation.  It is linear in the size of the
02272    *  deques.  Deques are considered equivalent if their sizes are equal,
02273    *  and if corresponding elements compare equal.
02274   */
02275   template<typename _Tp, typename _Alloc>
02276     inline bool
02277     operator==(const deque<_Tp, _Alloc>& __x,
02278                          const deque<_Tp, _Alloc>& __y)
02279     { return __x.size() == __y.size()
02280              && std::equal(__x.begin(), __x.end(), __y.begin()); }
02281 
02282   /**
02283    *  @brief  Deque ordering relation.
02284    *  @param  __x  A %deque.
02285    *  @param  __y  A %deque of the same type as @a __x.
02286    *  @return  True iff @a x is lexicographically less than @a __y.
02287    *
02288    *  This is a total ordering relation.  It is linear in the size of the
02289    *  deques.  The elements must be comparable with @c <.
02290    *
02291    *  See std::lexicographical_compare() for how the determination is made.
02292   */
02293   template<typename _Tp, typename _Alloc>
02294     inline bool
02295     operator<(const deque<_Tp, _Alloc>& __x,
02296               const deque<_Tp, _Alloc>& __y)
02297     { return std::lexicographical_compare(__x.begin(), __x.end(),
02298                                           __y.begin(), __y.end()); }
02299 
02300   /// Based on operator==
02301   template<typename _Tp, typename _Alloc>
02302     inline bool
02303     operator!=(const deque<_Tp, _Alloc>& __x,
02304                const deque<_Tp, _Alloc>& __y)
02305     { return !(__x == __y); }
02306 
02307   /// Based on operator<
02308   template<typename _Tp, typename _Alloc>
02309     inline bool
02310     operator>(const deque<_Tp, _Alloc>& __x,
02311               const deque<_Tp, _Alloc>& __y)
02312     { return __y < __x; }
02313 
02314   /// Based on operator<
02315   template<typename _Tp, typename _Alloc>
02316     inline bool
02317     operator<=(const deque<_Tp, _Alloc>& __x,
02318                const deque<_Tp, _Alloc>& __y)
02319     { return !(__y < __x); }
02320 
02321   /// Based on operator<
02322   template<typename _Tp, typename _Alloc>
02323     inline bool
02324     operator>=(const deque<_Tp, _Alloc>& __x,
02325                const deque<_Tp, _Alloc>& __y)
02326     { return !(__x < __y); }
02327 
02328   /// See std::deque::swap().
02329   template<typename _Tp, typename _Alloc>
02330     inline void
02331     swap(deque<_Tp,_Alloc>& __x, deque<_Tp,_Alloc>& __y)
02332     _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
02333     { __x.swap(__y); }
02334 
02335 #undef _GLIBCXX_DEQUE_BUF_SIZE
02336 
02337 _GLIBCXX_END_NAMESPACE_CONTAINER
02338 _GLIBCXX_END_NAMESPACE_VERSION
02339 } // namespace std
02340 
02341 #endif /* _STL_DEQUE_H */