stl_deque.h

gcc3.2.1源代码

  void
  push_front(const value_type& __t) 
  {
    if (_M_start._M_cur != _M_start._M_first) {
      _Construct(_M_start._M_cur - 1, __t);
      --_M_start._M_cur;
    }
    else
      _M_push_front_aux(__t);
  }

  void
  push_front()
  {
    if (_M_start._M_cur != _M_start._M_first) {
      _Construct(_M_start._M_cur - 1);
      --_M_start._M_cur;
    }
    else
      _M_push_front_aux();
  }


  void
  pop_back()
  {
    if (_M_finish._M_cur != _M_finish._M_first) {
      --_M_finish._M_cur;
      _Destroy(_M_finish._M_cur);
    }
    else
      _M_pop_back_aux();
  }

  void
  pop_front()
  {
    if (_M_start._M_cur != _M_start._M_last - 1) {
      _Destroy(_M_start._M_cur);
      ++_M_start._M_cur;
    }
    else 
      _M_pop_front_aux();
  }

public:                         // Insert

  iterator
  insert(iterator position, const value_type& __x)
  {
    if (position._M_cur == _M_start._M_cur) {
      push_front(__x);
      return _M_start;
    }
    else if (position._M_cur == _M_finish._M_cur) {
      push_back(__x);
      iterator __tmp = _M_finish;
      --__tmp;
      return __tmp;
    }
    else {
      return _M_insert_aux(position, __x);
    }
  }

  iterator
  insert(iterator __position)
  { return insert(__position, value_type()); }

  void
  insert(iterator __pos, size_type __n, const value_type& __x)
  { _M_fill_insert(__pos, __n, __x); }

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

  // Check whether it's an integral type.  If so, it's not an iterator.
  template<class _InputIterator>
    void
    insert(iterator __pos, _InputIterator __first, _InputIterator __last)
    {
      typedef typename _Is_integer<_InputIterator>::_Integral _Integral;
      _M_insert_dispatch(__pos, __first, __last, _Integral());
    }

  template<class _Integer>
    void
    _M_insert_dispatch(iterator __pos, _Integer __n, _Integer __x, __true_type)
    { _M_fill_insert(__pos, static_cast<size_type>(__n), static_cast<value_type>(__x)); }

  template<class _InputIterator>
    void
    _M_insert_dispatch(iterator __pos,
                       _InputIterator __first, _InputIterator __last,
                       __false_type)
    {
      typedef typename iterator_traits<_InputIterator>::iterator_category _IterCategory;
      insert(__pos, __first, __last, _IterCategory());
    }

  void resize(size_type __new_size, const value_type& __x) {
    const size_type __len = size();
    if (__new_size < __len) 
      erase(_M_start + __new_size, _M_finish);
    else
      insert(_M_finish, __new_size - __len, __x);
  }

  void resize(size_type new_size) { resize(new_size, value_type()); }

public:                         // Erase
  iterator erase(iterator __pos) {
    iterator __next = __pos;
    ++__next;
    size_type __index = __pos - _M_start;
    if (__index < (size() >> 1)) {
      copy_backward(_M_start, __pos, __next);
      pop_front();
    }
    else {
      copy(__next, _M_finish, __pos);
      pop_back();
    }
    return _M_start + __index;
  }

  iterator erase(iterator __first, iterator __last);
  void clear(); 

protected:                        // Internal construction/destruction

  void _M_fill_initialize(const value_type& __value);

  template <class _InputIterator>
  void _M_range_initialize(_InputIterator __first, _InputIterator __last,
                        input_iterator_tag);

  template <class _ForwardIterator>
  void _M_range_initialize(_ForwardIterator __first, _ForwardIterator __last,
                        forward_iterator_tag);

protected:                        // Internal push_* and pop_*

  void _M_push_back_aux(const value_type&);
  void _M_push_back_aux();
  void _M_push_front_aux(const value_type&);
  void _M_push_front_aux();
  void _M_pop_back_aux();
  void _M_pop_front_aux();

protected:                        // Internal insert functions

  template <class _InputIterator>
  void insert(iterator __pos, _InputIterator __first, _InputIterator __last,
              input_iterator_tag);

  template <class _ForwardIterator>
  void insert(iterator __pos,
              _ForwardIterator __first, _ForwardIterator __last,
              forward_iterator_tag);

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

  template <class _ForwardIterator>
  void _M_insert_aux(iterator __pos, 
                     _ForwardIterator __first, _ForwardIterator __last,
                     size_type __n);

  iterator _M_reserve_elements_at_front(size_type __n) {
    size_type __vacancies = _M_start._M_cur - _M_start._M_first;
    if (__n > __vacancies) 
      _M_new_elements_at_front(__n - __vacancies);
    return _M_start - difference_type(__n);
  }

  iterator _M_reserve_elements_at_back(size_type __n) {
    size_type __vacancies = (_M_finish._M_last - _M_finish._M_cur) - 1;
    if (__n > __vacancies)
      _M_new_elements_at_back(__n - __vacancies);
    return _M_finish + difference_type(__n);
  }

  void _M_new_elements_at_front(size_type __new_elements);
  void _M_new_elements_at_back(size_type __new_elements);

protected:                      // Allocation of _M_map and nodes

  // Makes sure the _M_map has space for new nodes.  Does not actually
  //  add the nodes.  Can invalidate _M_map pointers.  (And consequently, 
  //  deque iterators.)

  void _M_reserve_map_at_back (size_type __nodes_to_add = 1) {
    if (__nodes_to_add + 1 > _M_map_size - (_M_finish._M_node - _M_map))
      _M_reallocate_map(__nodes_to_add, false);
  }

  void _M_reserve_map_at_front (size_type __nodes_to_add = 1) {
    if (__nodes_to_add > size_type(_M_start._M_node - _M_map))
      _M_reallocate_map(__nodes_to_add, true);
  }

  void _M_reallocate_map(size_type __nodes_to_add, bool __add_at_front);
};

// Non-inline member functions

template <class _Tp, class _Alloc>
template <class _InputIter>
void deque<_Tp, _Alloc>
  ::_M_assign_aux(_InputIter __first, _InputIter __last, input_iterator_tag)
{
  iterator __cur = begin();
  for ( ; __first != __last && __cur != end(); ++__cur, ++__first)
    *__cur = *__first;
  if (__first == __last)
    erase(__cur, end());
  else
    insert(end(), __first, __last);
}

template <class _Tp, class _Alloc>
void deque<_Tp, _Alloc>::_M_fill_insert(iterator __pos,
                                        size_type __n, const value_type& __x)
{
  if (__pos._M_cur == _M_start._M_cur) {
    iterator __new_start = _M_reserve_elements_at_front(__n);
    try {
      uninitialized_fill(__new_start, _M_start, __x);
      _M_start = __new_start;
    }
    catch(...)
      {
	_M_destroy_nodes(__new_start._M_node, _M_start._M_node);
	__throw_exception_again;
      }
  }
  else if (__pos._M_cur == _M_finish._M_cur) {
    iterator __new_finish = _M_reserve_elements_at_back(__n);
    try {
      uninitialized_fill(_M_finish, __new_finish, __x);
      _M_finish = __new_finish;
    }
    catch(...)
      {
	_M_destroy_nodes(_M_finish._M_node + 1, __new_finish._M_node + 1);    
	__throw_exception_again;
      }
  }
  else 
    _M_insert_aux(__pos, __n, __x);
}

template <class _Tp, class _Alloc>
typename deque<_Tp,_Alloc>::iterator 
deque<_Tp,_Alloc>::erase(iterator __first, iterator __last)
{
  if (__first == _M_start && __last == _M_finish) {
    clear();
    return _M_finish;
  }
  else {
    difference_type __n = __last - __first;
    difference_type __elems_before = __first - _M_start;
    if (static_cast<size_type>(__elems_before) < (size() - __n) / 2) {
      copy_backward(_M_start, __first, __last);
      iterator __new_start = _M_start + __n;
      _Destroy(_M_start, __new_start);
      _M_destroy_nodes(_M_start._M_node, __new_start._M_node);
      _M_start = __new_start;
    }
    else {
      copy(__last, _M_finish, __first);
      iterator __new_finish = _M_finish - __n;
      _Destroy(__new_finish, _M_finish);
      _M_destroy_nodes(__new_finish._M_node + 1, _M_finish._M_node + 1);
      _M_finish = __new_finish;
    }
    return _M_start + __elems_before;
  }
}

template <class _Tp, class _Alloc> 
void deque<_Tp,_Alloc>::clear()
{
  for (_Map_pointer __node = _M_start._M_node + 1;
       __node < _M_finish._M_node;
       ++__node) {
    _Destroy(*__node, *__node + _S_buffer_size());
    _M_deallocate_node(*__node);
  }

  if (_M_start._M_node != _M_finish._M_node) {
    _Destroy(_M_start._M_cur, _M_start._M_last);
    _Destroy(_M_finish._M_first, _M_finish._M_cur);
    _M_deallocate_node(_M_finish._M_first);
  }
  else
    _Destroy(_M_start._M_cur, _M_finish._M_cur);

  _M_finish = _M_start;
}

/**
 *  @if maint
 *  @brief Fills the deque with copies of value.
 *  @param  value  Initial value.
 *  @return   Nothing.
 *  @pre _M_start and _M_finish have already been initialized, but none of the
 *       deque's elements have yet been constructed.
 *
 *  This function is called only when the user provides an explicit size (with
 *  or without an explicit exemplar value).
 *  @endif
*/
template <class _Tp, class _Alloc>
void deque<_Tp,_Alloc>::_M_fill_initialize(const value_type& __value)
{
  _Map_pointer __cur;
  try {
    for (__cur = _M_start._M_node; __cur < _M_finish._M_node; ++__cur)
      uninitialized_fill(*__cur, *__cur + _S_buffer_size(), __value);
    uninitialized_fill(_M_finish._M_first, _M_finish._M_cur, __value);
  }
  catch(...)
    {
      _Destroy(_M_start, iterator(*__cur, __cur));
      __throw_exception_again;
    }
}

/** @{
 *  @if maint
 *  @brief Fills the deque with whatever is in [first,last).
 *  @param  first  An input iterator.
 *  @param  last  An input iterator.
 *  @return   Nothing.
 *
 *  If the iterators are actually forward iterators (or better), then the
 *  memory layout can be done all at once.  Else we move forward using
 *  push_back on each value from the iterator.
 *  @endif
*/
template <class _Tp, class _Alloc> template <class _InputIterator>
void deque<_Tp,_Alloc>::_M_range_initialize(_InputIterator __first,
                                            _InputIterator __last,
                                            input_iterator_tag)
{
  _M_initialize_map(0);
  try {
    for ( ; __first != __last; ++__first)
      push_back(*__first);
  }
  catch(...)
    {
      clear();
      __throw_exception_again;
    }
}

template <class _Tp, class _Alloc> template <class _ForwardIterator>
void deque<_Tp,_Alloc>::_M_range_initialize(_ForwardIterator __first,
                                            _ForwardIterator __last,
                                            forward_iterator_tag)
{
  size_type __n = distance(__first, __last);
  _M_initialize_map(__n);

  _Map_pointer __cur_node;
  try {
    for (__cur_node = _M_start._M_node; 
         __cur_node < _M_finish._M_node; 
         ++__cur_node) {
      _ForwardIterator __mid = __first;
      advance(__mid, _S_buffer_size());
      uninitialized_copy(__first, __mid, *__cur_node);
      __first = __mid;
    }
    uninitialized_copy(__first, __last, _M_finish._M_first);
  }
  catch(...)
    {
      _Destroy(_M_start, iterator(*__cur_node, __cur_node));
      __throw_exception_again;
    }
}
/** @} */

// Called only if _M_finish._M_cur == _M_finish._M_last - 1.
template <class _Tp, class _Alloc>
void
deque<_Tp,_Alloc>::_M_push_back_aux(const value_type& __t)
{
  value_type __t_copy = __t;
  _M_reserve_map_at_back();
  *(_M_finish._M_node + 1) = _M_allocate_node();
  try {
    _Construct(_M_finish._M_cur, __t_copy);
    _M_finish._M_set_node(_M_finish._M_node + 1);
    _M_finish._M_cur = _M_finish._M_first;
  }
  catch(...)
    {
      _M_deallocate_node(*(_M_finish._M_node + 1));
      __throw_exception_again;
    }
}

// Called only if _M_finish._M_cur == _M_finish._M_last - 1.
template <class _Tp, class _Alloc>
void
deque<_Tp,_Alloc>::_M_push_back_aux()
{
  _M_reserve_map_at_back();
  *(_M_finish._M_node + 1) = _M_allocate_node();
  try {
    _Construct(_M_finish._M_cur);
    _M_finish._M_set_node(_M_finish._M_node + 1);
    _M_finish._M_cur = _M_finish._M_first;
  }