U++

// Vector implementation -*- C++ -*-

// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,

// 2011 Free Software Foundation, Inc.

//

// This file is part of the GNU ISO C++ Library.  This library is free

// software; you can redistribute it and/or modify it under the

// terms of the GNU General Public License as published by the

// Free Software Foundation; either version 3, or (at your option)

// any later version.

// This library is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional

// permissions described in the GCC Runtime Library Exception, version

// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and

// a copy of the GCC Runtime Library Exception along with this program;

// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see

// <http://www.gnu.org/licenses/>.

/*

 *

 * Copyright (c) 1994

 * Hewlett-Packard Company

 *

 * Permission to use, copy, modify, distribute and sell this software

 * and its documentation for any purpose is hereby granted without fee,

 * provided that the above copyright notice appear in all copies and

 * that both that copyright notice and this permission notice appear

 * in supporting documentation.  Hewlett-Packard Company makes no

 * representations about the suitability of this software for any

 * purpose.  It is provided "as is" without express or implied warranty.

 *

 *

 * Copyright (c) 1996

 * Silicon Graphics Computer Systems, Inc.

 *

 * Permission to use, copy, modify, distribute and sell this software

 * and its documentation for any purpose is hereby granted without fee,

 * provided that the above copyright notice appear in all copies and

 * that both that copyright notice and this permission notice appear

 * in supporting documentation.  Silicon Graphics makes no

 * representations about the suitability of this  software for any

 * purpose.  It is provided "as is" without express or implied warranty.

 */

/** @file bits/stl_vector.h

 *  This is an internal header file, included by other library headers.

 *  Do not attempt to use it directly. @headername{vector}

 */

#ifndef _STL_VECTOR_H

#define _STL_VECTOR_H 1

#include <bits/stl_iterator_base_funcs.h>

#include <bits/functexcept.h>

#include <bits/concept_check.h>

#include <initializer_list>

namespace std _GLIBCXX_VISIBILITY(default)

{

_GLIBCXX_BEGIN_NAMESPACE_CONTAINER

  /// See bits/stl_deque.h's _Deque_base for an explanation.

  template<typename _Tp, typename _Alloc>

    struct _Vector_base

    {

      typedef typename _Alloc::template rebind<_Tp>::other _Tp_alloc_type;

      struct _Vector_impl 

      : public _Tp_alloc_type

      {

        typename _Tp_alloc_type::pointer _M_start;

        typename _Tp_alloc_type::pointer _M_finish;

        typename _Tp_alloc_type::pointer _M_end_of_storage;

        _Vector_impl()

        : _Tp_alloc_type(), _M_start(0), _M_finish(0), _M_end_of_storage(0)

        { }

        _Vector_impl(_Tp_alloc_type const& __a)

        : _Tp_alloc_type(__a), _M_start(0), _M_finish(0), _M_end_of_storage(0)

        { }

      };

    public:

      typedef _Alloc allocator_type;

      _Tp_alloc_type&

      _M_get_Tp_allocator()

      { return *static_cast<_Tp_alloc_type*>(&this->_M_impl); }

      const _Tp_alloc_type&

      _M_get_Tp_allocator() const

      { return *static_cast<const _Tp_alloc_type*>(&this->_M_impl); }

      allocator_type

      get_allocator() const

      { return allocator_type(_M_get_Tp_allocator()); }

      _Vector_base()

      : _M_impl() { }

      _Vector_base(const allocator_type& __a)

      : _M_impl(__a) { }

      _Vector_base(size_t __n)

      : _M_impl()

      {

        this->_M_impl._M_start = this->_M_allocate(__n);

        this->_M_impl._M_finish = this->_M_impl._M_start;

        this->_M_impl._M_end_of_storage = this->_M_impl._M_start + __n;

      }

      _Vector_base(size_t __n, const allocator_type& __a)

      : _M_impl(__a)

      {

        this->_M_impl._M_start = this->_M_allocate(__n);

        this->_M_impl._M_finish = this->_M_impl._M_start;

        this->_M_impl._M_end_of_storage = this->_M_impl._M_start + __n;

      }

#ifdef __GXX_EXPERIMENTAL_CXX0X__

      _Vector_base(_Vector_base&& __x)

      : _M_impl(__x._M_get_Tp_allocator())

      {

        this->_M_impl._M_start = __x._M_impl._M_start;

        this->_M_impl._M_finish = __x._M_impl._M_finish;

        this->_M_impl._M_end_of_storage = __x._M_impl._M_end_of_storage;

        __x._M_impl._M_start = 0;

        __x._M_impl._M_finish = 0;

        __x._M_impl._M_end_of_storage = 0;

      }

#endif

      ~_Vector_base()

      { _M_deallocate(this->_M_impl._M_start, this->_M_impl._M_end_of_storage

                      - this->_M_impl._M_start); }

    public:

      _Vector_impl _M_impl;

      typename _Tp_alloc_type::pointer

      _M_allocate(size_t __n)

      { return __n != 0 ? _M_impl.allocate(__n) : 0; }

      void

      _M_deallocate(typename _Tp_alloc_type::pointer __p, size_t __n)

      {

        if (__p)

          _M_impl.deallocate(__p, __n);

      }

    };

  /**

   *  @brief A standard container which offers fixed time access to

   *  individual elements in any order.

   *

   *  @ingroup sequences

   *

   *  Meets the requirements of a <a href="tables.html#65">container</a>, a

   *  <a href="tables.html#66">reversible container</a>, and a

   *  <a href="tables.html#67">sequence</a>, including the

   *  <a href="tables.html#68">optional sequence requirements</a> with the

   *  %exception of @c push_front and @c pop_front.

   *

   *  In some terminology a %vector can be described as a dynamic

   *  C-style array, it offers fast and efficient access to individual

   *  elements in any order and saves the user from worrying about

   *  memory and size allocation.  Subscripting ( @c [] ) access is

   *  also provided as with C-style arrays.

  */

  template<typename _Tp, typename _Alloc = std::allocator<_Tp> >

    class vector : protected _Vector_base<_Tp, _Alloc>

    {

      // Concept requirements.

      typedef typename _Alloc::value_type                _Alloc_value_type;

      __glibcxx_class_requires(_Tp, _SGIAssignableConcept)

      __glibcxx_class_requires2(_Tp, _Alloc_value_type, _SameTypeConcept)

      typedef _Vector_base<_Tp, _Alloc>                         _Base;

      typedef typename _Base::_Tp_alloc_type                 _Tp_alloc_type;

    public:

      typedef _Tp                                         value_type;

      typedef typename _Tp_alloc_type::pointer           pointer;

      typedef typename _Tp_alloc_type::const_pointer     const_pointer;

      typedef typename _Tp_alloc_type::reference         reference;

      typedef typename _Tp_alloc_type::const_reference   const_reference;

      typedef __gnu_cxx::__normal_iterator<pointer, vector> iterator;

      typedef __gnu_cxx::__normal_iterator<const_pointer, vector>

      const_iterator;

      typedef std::reverse_iterator<const_iterator>  const_reverse_iterator;

      typedef std::reverse_iterator<iterator>                 reverse_iterator;

      typedef size_t                                         size_type;

      typedef ptrdiff_t                                         difference_type;

      typedef _Alloc                                         allocator_type;

    protected:

      using _Base::_M_allocate;

      using _Base::_M_deallocate;

      using _Base::_M_impl;

      using _Base::_M_get_Tp_allocator;

      bool _M_is_valid() const

      {

        return (this->_M_impl._M_end_of_storage == 0

                && this->_M_impl._M_start == 0

                && this->_M_impl._M_finish == 0)

              || (this->_M_impl._M_start <= this->_M_impl._M_finish

                  && this->_M_impl._M_finish <= this->_M_impl._M_end_of_storage

                  && this->_M_impl._M_start < this->_M_impl._M_end_of_storage);

      }

    public:

      // [23.2.4.1] construct/copy/destroy

      // (assign() and get_allocator() are also listed in this section)

      /**

       *  @brief  Default constructor creates no elements.

       */

      vector()

      : _Base() { }

      /**

       *  @brief  Creates a %vector with no elements.

       *  @param  a  An allocator object.

       */

      explicit

      vector(const allocator_type& __a)

      : _Base(__a) { }

#ifdef __GXX_EXPERIMENTAL_CXX0X__

      /**

       *  @brief  Creates a %vector with default constructed elements.

       *  @param  n  The number of elements to initially create.

       *

       *  This constructor fills the %vector with @a n default

       *  constructed elements.

       */

      explicit

      vector(size_type __n)

      : _Base(__n)

      { _M_default_initialize(__n); }

      /**

       *  @brief  Creates a %vector with copies of an exemplar element.

       *  @param  n  The number of elements to initially create.

       *  @param  value  An element to copy.

       *  @param  a  An allocator.

       *

       *  This constructor fills the %vector with @a n copies of @a value.

       */

      vector(size_type __n, const value_type& __value,

             const allocator_type& __a = allocator_type())

      : _Base(__n, __a)

      { _M_fill_initialize(__n, __value); }

#else

      /**

       *  @brief  Creates a %vector with copies of an exemplar element.

       *  @param  n  The number of elements to initially create.

       *  @param  value  An element to copy.

       *  @param  a  An allocator.

       *

       *  This constructor fills the %vector with @a n copies of @a value.

       */

      explicit

      vector(size_type __n, const value_type& __value = value_type(),

             const allocator_type& __a = allocator_type())

      : _Base(__n, __a)

      { _M_fill_initialize(__n, __value); }

#endif

      /**

       *  @brief  %Vector copy constructor.

       *  @param  x  A %vector of identical element and allocator types.

       *

       *  The newly-created %vector uses a copy of the allocation

       *  object used by @a x.  All the elements of @a x are copied,

       *  but any extra memory in

       *  @a x (for fast expansion) will not be copied.

       */

      vector(const vector& __x)

      : _Base(__x.size(), __x._M_get_Tp_allocator())

      { this->_M_impl._M_finish =

          std::__uninitialized_copy_a(__x.begin(), __x.end(),

                                      this->_M_impl._M_start,

                                      _M_get_Tp_allocator());

      }

#ifdef __GXX_EXPERIMENTAL_CXX0X__

      /**

       *  @brief  %Vector move constructor.

       *  @param  x  A %vector of identical element and allocator types.

       *

       *  The newly-created %vector contains the exact contents of @a x.

       *  The contents of @a x are a valid, but unspecified %vector.

       */

      vector(vector&& __x)

      : _Base(std::move(__x)) { }

      /**

       *  @brief  Builds a %vector from an initializer list.

       *  @param  l  An initializer_list.

       *  @param  a  An allocator.

       *

       *  Create a %vector consisting of copies of the elements in the

       *  initializer_list @a l.

       *

       *  This will call the element type's copy constructor N times

       *  (where N is @a l.size()) and do no memory reallocation.

       */

      vector(initializer_list<value_type> __l,

             const allocator_type& __a = allocator_type())

      : _Base(__a)

      {

        _M_range_initialize(__l.begin(), __l.end(),

                            random_access_iterator_tag());

      }

#endif

      /**

       *  @brief  Builds a %vector from a range.

       *  @param  first  An input iterator.

       *  @param  last  An input iterator.

       *  @param  a  An allocator.

       *

       *  Create a %vector consisting of copies of the elements from

       *  [first,last).

       *

       *  If the iterators are forward, bidirectional, or

       *  random-access, then this will call the elements' copy

       *  constructor N times (where N is distance(first,last)) and do

       *  no memory reallocation.  But if only input iterators are

       *  used, then this will do at most 2N calls to the copy

       *  constructor, and logN memory reallocations.

       */

      template<typename _InputIterator>

        vector(_InputIterator __first, _InputIterator __last,

               const allocator_type& __a = allocator_type())

        : _Base(__a)

        {

          // Check whether it's an integral type.  If so, it's not an iterator.

          typedef typename std::__is_integer<_InputIterator>::__type _Integral;

          _M_initialize_dispatch(__first, __last, _Integral());

        }

      /**

       *  The dtor only erases the elements, and note that if the

       *  elements themselves are pointers, the pointed-to memory is

       *  not touched in any way.  Managing the pointer is the user's

       *  responsibility.

       */

      ~vector()

      { std::_Destroy(this->_M_impl._M_start, this->_M_impl._M_finish,

                      _M_get_Tp_allocator()); }

      /**

       *  @brief  %Vector assignment operator.

       *  @param  x  A %vector of identical element and allocator types.

       *

       *  All the elements of @a x are copied, but any extra memory in

       *  @a x (for fast expansion) will not be copied.  Unlike the

       *  copy constructor, the allocator object is not copied.

       */

      vector&

      operator=(const vector& __x);

#ifdef __GXX_EXPERIMENTAL_CXX0X__

      /**

       *  @brief  %Vector move assignment operator.

       *  @param  x  A %vector of identical element and allocator types.

       *

       *  The contents of @a x are moved into this %vector (without copying).

       *  @a x is a valid, but unspecified %vector.

       */

      vector&

      operator=(vector&& __x)

      {

        // NB: DR 1204.

        // NB: DR 675.

        this->clear();

        this->swap(__x);

        return *this;

      }

      /**

       *  @brief  %Vector list assignment operator.

       *  @param  l  An initializer_list.

       *

       *  This function fills a %vector with copies of the elements in the

       *  initializer list @a l.

       *

       *  Note that the assignment completely changes the %vector and

       *  that the resulting %vector's size is the same as the number

       *  of elements assigned.  Old data may be lost.

       */

      vector&

      operator=(initializer_list<value_type> __l)

      {

        this->assign(__l.begin(), __l.end());

        return *this;

      }

#endif

      /**

       *  @brief  Assigns a given value to a %vector.

       *  @param  n  Number of elements to be assigned.

       *  @param  val  Value to be assigned.

       *

       *  This function fills a %vector with @a n copies of the given

       *  value.  Note that the assignment completely changes the

       *  %vector and that the resulting %vector's size is the same as

       *  the number of elements assigned.  Old data may be lost.

       */

      void

      assign(size_type __n, const value_type& __val)

      { _M_fill_assign(__n, __val); }

      /**

       *  @brief  Assigns a range to a %vector.

       *  @param  first  An input iterator.

       *  @param  last   An input iterator.

       *

       *  This function fills a %vector with copies of the elements in the

       *  range [first,last).

       *

       *  Note that the assignment completely changes the %vector and

       *  that the resulting %vector's size is the same as the number

       *  of elements assigned.  Old data may be lost.

       */

      template<typename _InputIterator>

        void

        assign(_InputIterator __first, _InputIterator __last)

        {

          // Check whether it's an integral type.  If so, it's not an iterator.

          typedef typename std::__is_integer<_InputIterator>::__type _Integral;

          _M_assign_dispatch(__first, __last, _Integral());

        }

#ifdef __GXX_EXPERIMENTAL_CXX0X__

      /**

       *  @brief  Assigns an initializer list to a %vector.

       *  @param  l  An initializer_list.

       *

       *  This function fills a %vector with copies of the elements in the

       *  initializer list @a l.

       *

       *  Note that the assignment completely changes the %vector and

       *  that the resulting %vector's size is the same as the number

       *  of elements assigned.  Old data may be lost.

       */

      void

      assign(initializer_list<value_type> __l)

      { this->assign(__l.begin(), __l.end()); }

#endif

      /// Get a copy of the memory allocation object.

      using _Base::get_allocator;

      // iterators

      /**

       *  Returns a read/write iterator that points to the first

       *  element in the %vector.  Iteration is done in ordinary

       *  element order.

       */

      iterator

      begin()

      {

#if __google_stl_debug_dangling_vector

        if (!this->_M_is_valid())

          __throw_logic_error("begin() on corrupt (dangling?) vector");

#endif

        return iterator(this->_M_impl._M_start);

      }

      /**

       *  Returns a read-only (constant) iterator that points to the

       *  first element in the %vector.  Iteration is done in ordinary

       *  element order.

       */

      const_iterator

      begin() const

      {

#if __google_stl_debug_dangling_vector

        if (!this->_M_is_valid())

          __throw_logic_error("begin() on corrupt (dangling?) vector");

#endif

        return const_iterator(this->_M_impl._M_start);

      }

      /**

       *  Returns a read/write iterator that points one past the last

       *  element in the %vector.  Iteration is done in ordinary

       *  element order.

       */

      iterator

      end()

      {

#if __google_stl_debug_dangling_vector

        if (!this->_M_is_valid())

          __throw_logic_error("end() on corrupt (dangling?) vector");

#endif

        return iterator(this->_M_impl._M_finish);

      }

      /**

       *  Returns a read-only (constant) iterator that points one past

       *  the last element in the %vector.  Iteration is done in

       *  ordinary element order.

       */

      const_iterator

      end() const

      {

#if __google_stl_debug_dangling_vector

        if (!this->_M_is_valid())

          __throw_logic_error("end() on corrupt (dangling?) vector");

#endif

        return const_iterator(this->_M_impl._M_finish);

      }

      /**

       *  Returns a read/write reverse iterator that points to the

       *  last element in the %vector.  Iteration is done in reverse

       *  element order.

       */

      reverse_iterator

      rbegin()

      { return reverse_iterator(end()); }

      /**

       *  Returns a read-only (constant) reverse iterator that points

       *  to the last element in the %vector.  Iteration is done in

       *  reverse element order.

       */

      const_reverse_iterator

      rbegin() const

      { return const_reverse_iterator(end()); }

      /**

       *  Returns a read/write reverse iterator that points to one

       *  before the first element in the %vector.  Iteration is done

       *  in reverse element order.

       */

      reverse_iterator

      rend()

      { return reverse_iterator(begin()); }

      /**

       *  Returns a read-only (constant) reverse iterator that points

       *  to one before the first element in the %vector.  Iteration

       *  is done in reverse element order.

       */

      const_reverse_iterator

      rend() const

      { return const_reverse_iterator(begin()); }

#ifdef __GXX_EXPERIMENTAL_CXX0X__

      /**

       *  Returns a read-only (constant) iterator that points to the

       *  first element in the %vector.  Iteration is done in ordinary

       *  element order.

       */

      const_iterator

      cbegin() const

      { return const_iterator(this->_M_impl._M_start); }

      /**

       *  Returns a read-only (constant) iterator that points one past

       *  the last element in the %vector.  Iteration is done in

       *  ordinary element order.

       */

      const_iterator

      cend() const

      { return const_iterator(this->_M_impl._M_finish); }

      /**

       *  Returns a read-only (constant) reverse iterator that points

       *  to the last element in the %vector.  Iteration is done in

       *  reverse element order.

       */

      const_reverse_iterator

      crbegin() const

      { return const_reverse_iterator(end()); }

      /**

       *  Returns a read-only (constant) reverse iterator that points

       *  to one before the first element in the %vector.  Iteration

       *  is done in reverse element order.

       */

      const_reverse_iterator

      crend() const

      { return const_reverse_iterator(begin()); }

#endif

      // [23.2.4.2] capacity

      /**  Returns the number of elements in the %vector.  */

      size_type

      size() const

      {

#if __google_stl_debug_dangling_vector

        if (!this->_M_is_valid())

          __throw_logic_error("size() on corrupt (dangling?) vector");

#endif

        return size_type(this->_M_impl._M_finish - this->_M_impl._M_start);

      }

      /**  Returns the size() of the largest possible %vector.  */

      size_type

      max_size() const

      { return _M_get_Tp_allocator().max_size(); }

#ifdef __GXX_EXPERIMENTAL_CXX0X__

      /**

       *  @brief  Resizes the %vector to the specified number of elements.

       *  @param  new_size  Number of elements the %vector should contain.

       *

       *  This function will %resize the %vector to the specified

       *  number of elements.  If the number is smaller than the

       *  %vector's current size the %vector is truncated, otherwise

       *  default constructed elements are appended.

       */

      void

      resize(size_type __new_size)

      {

        if (__new_size > size())

          _M_default_append(__new_size - size());

        else if (__new_size < size())

          _M_erase_at_end(this->_M_impl._M_start + __new_size);

      }

      /**

       *  @brief  Resizes the %vector to the specified number of elements.

       *  @param  new_size  Number of elements the %vector should contain.

       *  @param  x  Data with which new elements should be populated.

       *

       *  This function will %resize the %vector to the specified

       *  number of elements.  If the number is smaller than the

       *  %vector's current size the %vector is truncated, otherwise

       *  the %vector is extended and new elements are populated with

       *  given data.

       */

      void

      resize(size_type __new_size, const value_type& __x)

      {

        if (__new_size > size())

          insert(end(), __new_size - size(), __x);

        else if (__new_size < size())

          _M_erase_at_end(this->_M_impl._M_start + __new_size);

      }

#else

      /**

       *  @brief  Resizes the %vector to the specified number of elements.

       *  @param  new_size  Number of elements the %vector should contain.

       *  @param  x  Data with which new elements should be populated.

       *

       *  This function will %resize the %vector to the specified

       *  number of elements.  If the number is smaller than the

       *  %vector's current size the %vector is truncated, otherwise

       *  the %vector is extended and new elements are populated with

       *  given data.

       */

      void

      resize(size_type __new_size, value_type __x = value_type())

      {

        if (__new_size > size())

          insert(end(), __new_size - size(), __x);

        else if (__new_size < size())

          _M_erase_at_end(this->_M_impl._M_start + __new_size);

      }

#endif

#ifdef __GXX_EXPERIMENTAL_CXX0X__

      /**  A non-binding request to reduce capacity() to size().  */

      void

      shrink_to_fit()

      { std::__shrink_to_fit<vector>::_S_do_it(*this); }

#endif

      /**

       *  Returns the total number of elements that the %vector can

       *  hold before needing to allocate more memory.

       */

      size_type

      capacity() const

      {

#if __google_stl_debug_dangling_vector

        if (!this->_M_is_valid())

          __throw_logic_error("capacity() on corrupt (dangling?) vector");

#endif

        return size_type(this->_M_impl._M_end_of_storage

                         - this->_M_impl._M_start); }

      /**

       *  Returns true if the %vector is empty.  (Thus begin() would

       *  equal end().)

       */

      bool

      empty() const

      { return begin() == end(); }

      /**

       *  @brief  Attempt to preallocate enough memory for specified number of

       *          elements.

       *  @param  n  Number of elements required.

       *  @throw  std::length_error  If @a n exceeds @c max_size().

       *

       *  This function attempts to reserve enough memory for the

       *  %vector to hold the specified number of elements.  If the

       *  number requested is more than max_size(), length_error is

       *  thrown.

       *

       *  The advantage of this function is that if optimal code is a

       *  necessity and the user can determine the number of elements

       *  that will be required, the user can reserve the memory in

       *  %advance, and thus prevent a possible reallocation of memory

       *  and copying of %vector data.

       */

      void

      reserve(size_type __n);

      // element access

      /**

       *  @brief  Subscript access to the data contained in the %vector.

       *  @param n The index of the element for which data should be

       *  accessed.

       *  @return  Read/write reference to data.

       *

       *  This operator allows for easy, array-style, data access.

       *  Note that data access with this operator is unchecked and

       *  out_of_range lookups are not defined. (For checked lookups

       *  see at().)

       *

       *  Local modification: range checks are performed if

       *  __google_stl_debug_vector is defined to non-zero.

       */

      reference

      operator[](size_type __n)

      {

#if __google_stl_debug_vector

        _M_range_check(__n);

#endif

        return *(this->_M_impl._M_start + __n);

      }

      /**

       *  @brief  Subscript access to the data contained in the %vector.

       *  @param n The index of the element for which data should be

       *  accessed.

       *  @return  Read-only (constant) reference to data.

       *

       *  This operator allows for easy, array-style, data access.

       *  Note that data access with this operator is unchecked and

       *  out_of_range lookups are not defined. (For checked lookups

       *  see at().)

       *

       *  Local modification: range checks are performed if

       *  __google_stl_debug_vector is defined to non-zero.

       */

      const_reference

      operator[](size_type __n) const

      {

#if __google_stl_debug_vector

        _M_range_check(__n);

#endif

        return *(this->_M_impl._M_start + __n);

      }

    protected:

      /// Safety check used only from at().

      void

      _M_range_check(size_type __n) const

      {

        if (__n >= this->size())

          __throw_out_of_range(__N("vector::_M_range_check"));

      }

    public:

      /**

       *  @brief  Provides access to the data contained in the %vector.

       *  @param n The index of the element for which data should be

       *  accessed.

       *  @return  Read/write reference to data.

       *  @throw  std::out_of_range  If @a n is an invalid index.

       *

       *  This function provides for safer data access.  The parameter

       *  is first checked that it is in the range of the vector.  The

       *  function throws out_of_range if the check fails.

       */

      reference

      at(size_type __n)

      {

        _M_range_check(__n);

        return (*this)[__n]; 

      }

      /**

       *  @brief  Provides access to the data contained in the %vector.

       *  @param n The index of the element for which data should be

       *  accessed.

       *  @return  Read-only (constant) reference to data.

       *  @throw  std::out_of_range  If @a n is an invalid index.

       *

       *  This function provides for safer data access.  The parameter

       *  is first checked that it is in the range of the vector.  The

       *  function throws out_of_range if the check fails.

       */

      const_reference

      at(size_type __n) const

      {

        _M_range_check(__n);

        return (*this)[__n];

      }

      /**

       *  Returns a read/write reference to the data at the first

       *  element of the %vector.

       */

      reference

      front()

      { return *begin(); }

      /**

       *  Returns a read-only (constant) reference to the data at the first

       *  element of the %vector.

       */

      const_reference

      front() const

      { return *begin(); }

      /**

       *  Returns a read/write reference to the data at the last

       *  element of the %vector.

       */

      reference

      back()

      { return *(end() - 1); }

      /**

       *  Returns a read-only (constant) reference to the data at the

       *  last element of the %vector.

       */

      const_reference

      back() const

      { return *(end() - 1); }

      // _GLIBCXX_RESOLVE_LIB_DEFECTS

      // DR 464. Suggestion for new member functions in standard containers.

      // data access

      /**

       *   Returns a pointer such that [data(), data() + size()) is a valid

       *   range.  For a non-empty %vector, data() == &front().

       */

#ifdef __GXX_EXPERIMENTAL_CXX0X__

      _Tp*

#else

      pointer

#endif

      data()

      { return std::__addressof(front()); }

#ifdef __GXX_EXPERIMENTAL_CXX0X__

      const _Tp*

#else

      const_pointer

#endif

      data() const

      { return std::__addressof(front()); }

      // [23.2.4.3] modifiers

      /**

       *  @brief  Add data to the end of the %vector.

       *  @param  x  Data to be added.

       *

       *  This is a typical stack operation.  The function creates an

       *  element at the end of the %vector and assigns the given data

       *  to it.  Due to the nature of a %vector this operation can be

       *  done in constant time if the %vector has preallocated space

       *  available.

       */

      void

      push_back(const value_type& __x)

      {

        if (this->_M_impl._M_finish != this->_M_impl._M_end_of_storage)

          {

            this->_M_impl.construct(this->_M_impl._M_finish, __x);

            ++this->_M_impl._M_finish;

          }

        else

          _M_insert_aux(end(), __x);

      }

#ifdef __GXX_EXPERIMENTAL_CXX0X__

      void

      push_back(value_type&& __x)

      { emplace_back(std::move(__x)); }

      template<typename... _Args>

        void

        emplace_back(_Args&&... __args);

#endif

      /**

       *  @brief  Removes last element.

       *

       *  This is a typical stack operation. It shrinks the %vector by one.

       *

       *  Note that no data is returned, and if the last element's

       *  data is needed, it should be retrieved before pop_back() is

       *  called.

       */

      void

      pop_back()

      {

        --this->_M_impl._M_finish;

        this->_M_impl.destroy(this->_M_impl._M_finish);

      }

#ifdef __GXX_EXPERIMENTAL_CXX0X__

      /**

       *  @brief  Inserts an object in %vector before specified iterator.

       *  @param  position  An iterator into the %vector.

       *  @param  args  Arguments.

       *  @return  An iterator that points to the inserted data.

       *

       *  This function will insert an object of type T constructed

       *  with T(std::forward<Args>(args)...) before the specified location.

       *  Note that this kind of operation could be expensive for a %vector

       *  and if it is frequently used the user should consider using

       *  std::list.

       */

      template<typename... _Args>

        iterator

        emplace(iterator __position, _Args&&... __args);

#endif

      /**

       *  @brief  Inserts given value into %vector before specified iterator.

       *  @param  position  An iterator into the %vector.

       *  @param  x  Data to be inserted.

       *  @return  An iterator that points to the inserted data.

       *

       *  This function will insert a copy of the given value before

       *  the specified location.  Note that this kind of operation

       *  could be expensive for a %vector and if it is frequently

       *  used the user should consider using std::list.

       */

      iterator

      insert(iterator __position, const value_type& __x);

#ifdef __GXX_EXPERIMENTAL_CXX0X__

      /**

       *  @brief  Inserts given rvalue into %vector before specified iterator.

       *  @param  position  An iterator into the %vector.

       *  @param  x  Data to be inserted.

       *  @return  An iterator that points to the inserted data.

       *

       *  This function will insert a copy of the given rvalue before

       *  the specified location.  Note that this kind of operation

       *  could be expensive for a %vector and if it is frequently

       *  used the user should consider using std::list.

       */

      iterator

      insert(iterator __position, value_type&& __x)

      { return emplace(__position, std::move(__x)); }

      /**

       *  @brief  Inserts an initializer_list into the %vector.

       *  @param  position  An iterator into the %vector.

       *  @param  l  An initializer_list.

       *

       *  This function will insert copies of the data in the 

       *  initializer_list @a l into the %vector before the location

       *  specified by @a position.

       *

       *  Note that this kind of operation could be expensive for a

       *  %vector and if it is frequently used the user should

       *  consider using std::list.

       */

      void

      insert(iterator __position, initializer_list<value_type> __l)

      { this->insert(__position, __l.begin(), __l.end()); }

#endif

      /**

       *  @brief  Inserts a number of copies of given data into the %vector.

       *  @param  position  An iterator into the %vector.

       *  @param  n  Number of elements to be inserted.

       *  @param  x  Data to be inserted.

       *

       *  This function will insert a specified number of copies of

       *  the given data before the location specified by @a position.

       *

       *  Note that this kind of operation could be expensive for a

       *  %vector and if it is frequently used the user should

       *  consider using std::list.

       */

      void

      insert(iterator __position, size_type __n, const value_type& __x)

      { _M_fill_insert(__position, __n, __x); }

      /**

       *  @brief  Inserts a range into the %vector.

       *  @param  position  An iterator into the %vector.

       *  @param  first  An input iterator.

       *  @param  last   An input iterator.

       *

       *  This function will insert copies of the data in the range

       *  [first,last) into the %vector before the location specified

       *  by @a pos.

       *

       *  Note that this kind of operation could be expensive for a

       *  %vector and if it is frequently used the user should

       *  consider using std::list.

       */

      template<typename _InputIterator>

        void

        insert(iterator __position, _InputIterator __first,

               _InputIterator __last)

        {

          // Check whether it's an integral type.  If so, it's not an iterator.

          typedef typename std::__is_integer<_InputIterator>::__type _Integral;

          _M_insert_dispatch(__position, __first, __last, _Integral());

        }

      /**

       *  @brief  Remove element at given position.

       *  @param  position  Iterator pointing to element to be erased.

       *  @return  An iterator pointing to the next element (or end()).

       *

       *  This function will erase the element at the given position and thus

       *  shorten the %vector by one.

       *

       *  Note This operation could be expensive and if it is

       *  frequently used the user should consider using std::list.

       *  The user is also cautioned that this function only erases

       *  the element, and that if the element is itself a pointer,

       *  the pointed-to memory is not touched in any way.  Managing

       *  the pointer is the user's responsibility.

       */

      iterator

      erase(iterator __position);

      /**

       *  @brief  Remove a range of elements.

       *  @param  first  Iterator pointing to the first element to be erased.

       *  @param  last  Iterator pointing to one past the last element to be

       *                erased.

       *  @return  An iterator pointing to the element pointed to by @a last

       *           prior to erasing (or end()).

       *

       *  This function will erase the elements in the range [first,last) and

       *  shorten the %vector accordingly.

       *

       *  Note This operation could be expensive and if it is

       *  frequently used the user should consider using std::list.

       *  The user is also cautioned that this function only erases

       *  the elements, and that if the elements themselves are

       *  pointers, the pointed-to memory is not touched in any way.

       *  Managing the pointer is the user's responsibility.

       */

      iterator

      erase(iterator __first, iterator __last);

      /**

       *  @brief  Swaps data with another %vector.

       *  @param  x  A %vector of the same element and allocator types.

       *

       *  This exchanges the elements between two vectors in constant time.

       *  (Three pointers, so it should be quite fast.)

       *  Note that the global std::swap() function is specialized such that

       *  std::swap(v1,v2) will feed to this function.

       */

      void

      swap(vector& __x)

      {

#if __google_stl_debug_dangling_vector

        if (!this->_M_is_valid() || !__x._M_is_valid())

          __throw_logic_error("swap() on corrupt (dangling?) vector");

#endif

        std::swap(this->_M_impl._M_start, __x._M_impl._M_start);

        std::swap(this->_M_impl._M_finish, __x._M_impl._M_finish);

        std::swap(this->_M_impl._M_end_of_storage,

                  __x._M_impl._M_end_of_storage);

        // _GLIBCXX_RESOLVE_LIB_DEFECTS

        // 431. Swapping containers with unequal allocators.

        std::__alloc_swap<_Tp_alloc_type>::_S_do_it(_M_get_Tp_allocator(),

                                                    __x._M_get_Tp_allocator());

      }

      /**

       *  Erases all the elements.  Note that this function only erases the

       *  elements, and that if the elements themselves are pointers, the

       *  pointed-to memory is not touched in any way.  Managing the pointer is

       *  the user's responsibility.

       */

      void

      clear()

      {

#if __google_stl_debug_dangling_vector

        if (!this->_M_is_valid())

          __throw_logic_error("clear() on corrupt (dangling?) vector");

#endif

        _M_erase_at_end(this->_M_impl._M_start);

      }

    protected:

      /**

       *  Memory expansion handler.  Uses the member allocation function to

       *  obtain @a n bytes of memory, and then copies [first,last) into it.

       */

      template<typename _ForwardIterator>

        pointer

        _M_allocate_and_copy(size_type __n,

                             _ForwardIterator __first, _ForwardIterator __last)

        {

          pointer __result = this->_M_allocate(__n);

          __try

            {

              std::__uninitialized_copy_a(__first, __last, __result,

                                          _M_get_Tp_allocator());

              return __result;

            }

          __catch(...)

            {

              _M_deallocate(__result, __n);

              __throw_exception_again;

            }

        }

      // Internal constructor functions follow.

      // Called by the range constructor to implement [23.1.1]/9

      // _GLIBCXX_RESOLVE_LIB_DEFECTS

      // 438. Ambiguity in the "do the right thing" clause

      template<typename _Integer>

        void

        _M_initialize_dispatch(_Integer __n, _Integer __value, __true_type)

        {

          this->_M_impl._M_start = _M_allocate(static_cast<size_type>(__n));

          this->_M_impl._M_end_of_storage =

            this->_M_impl._M_start + static_cast<size_type>(__n);

          _M_fill_initialize(static_cast<size_type>(__n), __value);

        }

      // Called by the range constructor to implement [23.1.1]/9

      template<typename _InputIterator>

        void

        _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,

                               __false_type)

        {

          typedef typename std::iterator_traits<_InputIterator>::

            iterator_category _IterCategory;

          _M_range_initialize(__first, __last, _IterCategory());

        }

      // Called by the second initialize_dispatch above

      template<typename _InputIterator>

        void

        _M_range_initialize(_InputIterator __first,

                            _InputIterator __last, std::input_iterator_tag)

        {

          for (; __first != __last; ++__first)

            push_back(*__first);

        }

      // Called by the second initialize_dispatch above

      template<typename _ForwardIterator>

        void

        _M_range_initialize(_ForwardIterator __first,

                            _ForwardIterator __last, std::forward_iterator_tag)

        {

          const size_type __n = std::distance(__first, __last);

          this->_M_impl._M_start = this->_M_allocate(__n);

          this->_M_impl._M_end_of_storage = this->_M_impl._M_start + __n;

          this->_M_impl._M_finish =

            std::__uninitialized_copy_a(__first, __last,

                                        this->_M_impl._M_start,

                                        _M_get_Tp_allocator());

        }

      // Called by the first initialize_dispatch above and by the

      // vector(n,value,a) constructor.

      void

      _M_fill_initialize(size_type __n, const value_type& __value)

      {

        std::__uninitialized_fill_n_a(this->_M_impl._M_start, __n, __value, 

                                      _M_get_Tp_allocator());

        this->_M_impl._M_finish = this->_M_impl._M_end_of_storage;

      }

#ifdef __GXX_EXPERIMENTAL_CXX0X__

      // Called by the vector(n) constructor.

      void

      _M_default_initialize(size_type __n)

      {

        std::__uninitialized_default_n_a(this->_M_impl._M_start, __n, 

                                         _M_get_Tp_allocator());

        this->_M_impl._M_finish = this->_M_impl._M_end_of_storage;

      }

#endif

      // Internal assign functions follow.  The *_aux functions do the actual

      // assignment work for the range versions.

      // Called by the range assign to implement [23.1.1]/9

      // _GLIBCXX_RESOLVE_LIB_DEFECTS

      // 438. Ambiguity in the "do the right thing" clause

      template<typename _Integer>

        void

        _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)

        { _M_fill_assign(__n, __val); }

      // Called by the range assign to implement [23.1.1]/9

      template<typename _InputIterator>

        void

        _M_assign_dispatch(_InputIterator __first, _InputIterator __last,

                           __false_type)

        {

          typedef typename std::iterator_traits<_InputIterator>::

            iterator_category _IterCategory;

          _M_assign_aux(__first, __last, _IterCategory());

        }

      // Called by the second assign_dispatch above

      template<typename _InputIterator>

        void

        _M_assign_aux(_InputIterator __first, _InputIterator __last,

                      std::input_iterator_tag);

      // Called by the second assign_dispatch above

      template<typename _ForwardIterator>

        void

        _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,

                      std::forward_iterator_tag);

      // Called by assign(n,t), and the range assign when it turns out

      // to be the same thing.

      void

      _M_fill_assign(size_type __n, const value_type& __val);

      // Internal insert functions follow.

      // Called by the range insert to implement [23.1.1]/9

      // _GLIBCXX_RESOLVE_LIB_DEFECTS

      // 438. Ambiguity in the "do the right thing" clause

      template<typename _Integer>

        void

        _M_insert_dispatch(iterator __pos, _Integer __n, _Integer __val,

                           __true_type)

        { _M_fill_insert(__pos, __n, __val); }

      // Called by the range insert to implement [23.1.1]/9

      template<typename _InputIterator>

        void

        _M_insert_dispatch(iterator __pos, _InputIterator __first,

                           _InputIterator __last, __false_type)

        {

          typedef typename std::iterator_traits<_InputIterator>::

            iterator_category _IterCategory;

          _M_range_insert(__pos, __first, __last, _IterCategory());

        }

      // Called by the second insert_dispatch above

      template<typename _InputIterator>

        void

        _M_range_insert(iterator __pos, _InputIterator __first,

                        _InputIterator __last, std::input_iterator_tag);

      // Called by the second insert_dispatch above

      template<typename _ForwardIterator>

        void

        _M_range_insert(iterator __pos, _ForwardIterator __first,

                        _ForwardIterator __last, std::forward_iterator_tag);

      // Called by insert(p,n,x), and the range insert when it turns out to be

      // the same thing.

      void

      _M_fill_insert(iterator __pos, size_type __n, const value_type& __x);

#ifdef __GXX_EXPERIMENTAL_CXX0X__

      // Called by resize(n).

      void

      _M_default_append(size_type __n);

#endif

      // Called by insert(p,x)

#ifndef __GXX_EXPERIMENTAL_CXX0X__

      void

      _M_insert_aux(iterator __position, const value_type& __x);

#else

      template<typename... _Args>

        void

        _M_insert_aux(iterator __position, _Args&&... __args);

#endif

      // Called by the latter.

      size_type

      _M_check_len(size_type __n, const char* __s) const

      {

        if (max_size() - size() < __n)

          __throw_length_error(__N(__s));

        const size_type __len = size() + std::max(size(), __n);

        return (__len < size() || __len > max_size()) ? max_size() : __len;

      }

      // Internal erase functions follow.

      // Called by erase(q1,q2), clear(), resize(), _M_fill_assign,

      // _M_assign_aux.

      void

      _M_erase_at_end(pointer __pos)

      {

        std::_Destroy(__pos, this->_M_impl._M_finish, _M_get_Tp_allocator());

        this->_M_impl._M_finish = __pos;

      }

    };

  /**

   *  @brief  Vector equality comparison.

   *  @param  x  A %vector.

   *  @param  y  A %vector of the same type as @a x.

   *  @return  True iff the size and elements of the vectors are equal.

   *

   *  This is an equivalence relation.  It is linear in the size of the

   *  vectors.  Vectors are considered equivalent if their sizes are equal,

   *  and if corresponding elements compare equal.

  */

  template<typename _Tp, typename _Alloc>

    inline bool

    operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)

    { return (__x.size() == __y.size()

              && std::equal(__x.begin(), __x.end(), __y.begin())); }

  /**

   *  @brief  Vector ordering relation.

   *  @param  x  A %vector.

   *  @param  y  A %vector of the same type as @a x.

   *  @return  True iff @a x is lexicographically less than @a y.

   *

   *  This is a total ordering relation.  It is linear in the size of the

   *  vectors.  The elements must be comparable with @c <.

   *

   *  See std::lexicographical_compare() for how the determination is made.

  */

  template<typename _Tp, typename _Alloc>

    inline bool

    operator<(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)

    { return std::lexicographical_compare(__x.begin(), __x.end(),

                                          __y.begin(), __y.end()); }

  /// Based on operator==

  template<typename _Tp, typename _Alloc>

    inline bool

    operator!=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)

    { return !(__x == __y); }

  /// Based on operator<

  template<typename _Tp, typename _Alloc>

    inline bool

    operator>(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)

    { return __y < __x; }

  /// Based on operator<

  template<typename _Tp, typename _Alloc>

    inline bool

    operator<=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)

    { return !(__y < __x); }

  /// Based on operator<

  template<typename _Tp, typename _Alloc>

    inline bool

    operator>=(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y)

    { return !(__x < __y); }

  /// See std::vector::swap().

  template<typename _Tp, typename _Alloc>

    inline void

    swap(vector<_Tp, _Alloc>& __x, vector<_Tp, _Alloc>& __y)

    { __x.swap(__y); }

_GLIBCXX_END_NAMESPACE_CONTAINER

} // namespace std

#endif /* _STL_VECTOR_H */