stl_vector.h

gcc3.2.1源代码

      _M_finish = uninitialized_fill_n(_M_start, __n, __value);
    }

  template<class _InputIterator>
    void
	_M_initialize_aux(_InputIterator __first, _InputIterator __last, __false_type)
	{
	  typedef typename iterator_traits<_InputIterator>::iterator_category _IterCategory;
	  _M_range_initialize(__first, __last, _IterCategory());
	}

  ~vector()
  { _Destroy(_M_start, _M_finish); }

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

  /**
   *  @brief  Attempt to preallocate enough memory for specified number of
   *          elements.
   *  @param  n  Number of elements required
   *
   *  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 and thus prevent a possible
   *  reallocation of memory and copy of vector data.
  */
  void reserve(size_type __n) {
    if (capacity() < __n) {
      const size_type __old_size = size();
      pointer __tmp = _M_allocate_and_copy(__n, _M_start, _M_finish);
      _Destroy(_M_start, _M_finish);
      _M_deallocate(_M_start, _M_end_of_storage - _M_start);
      _M_start = __tmp;
      _M_finish = __tmp + __old_size;
      _M_end_of_storage = _M_start + __n;
    }
  }

  // assign(), a generalized assignment member function.  Two
  // versions: one that takes a count, and one that takes a range.
  // The range version is a member template, so we dispatch on whether
  // or not the type is an integer.

  /**
   *  @brief  Assigns a given value or range to a vector.
   *  @param  n  Number of elements to be assigned.
   *  @param  val  Value to be assigned.
   *
   *  This function can be used to assign a range to a vector or fill it
   *  with a specified number of 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 _Tp& __val) { _M_fill_assign(__n, __val); }
  void _M_fill_assign(size_type __n, const _Tp& __val);

  template<class _InputIterator>
    void
    assign(_InputIterator __first, _InputIterator __last)
    {
      typedef typename _Is_integer<_InputIterator>::_Integral _Integral;
      _M_assign_dispatch(__first, __last, _Integral());
    }

  template<class _Integer>
    void
     _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
     { _M_fill_assign((size_type) __n, (_Tp) __val); }

  template<class _InputIter>
    void
    _M_assign_dispatch(_InputIter __first, _InputIter __last, __false_type)
    {
      typedef typename iterator_traits<_InputIter>::iterator_category _IterCategory;
      _M_assign_aux(__first, __last, _IterCategory());
    }

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

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

  /**
   *  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 first
   *  element of the vector.
  */
  const_reference back() const { return *(end() - 1); }

  /**
   *  @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 _Tp& __x)
  {
    if (_M_finish != _M_end_of_storage) {
      _Construct(_M_finish, __x);
      ++_M_finish;
    }
    else
      _M_insert_aux(end(), __x);
  }

#ifdef _GLIBCPP_DEPRECATED
  /**
   *  Add an element to the end of the vector.  The element is
   *  default-constructed.
   *
   *  @note You must define _GLIBCPP_DEPRECATED to make this visible; see
   *        c++config.h.
  */
  void
  push_back()
  {
    if (_M_finish != _M_end_of_storage) {
      _Construct(_M_finish);
      ++_M_finish;
    }
    else
      _M_insert_aux(end());
  }
#endif

  void
  swap(vector<_Tp, _Alloc>& __x)
  {
    std::swap(_M_start, __x._M_start);
    std::swap(_M_finish, __x._M_finish);
    std::swap(_M_end_of_storage, __x._M_end_of_storage);
  }

  /**
   *  @brief  Inserts given value into vector at specified element.
   *  @param  position  An iterator that points to the element where data
   *                    should be inserted.
   *  @param  x  Data to be inserted.
   *  @return  An iterator that points to the inserted data.
   *
   *  This function will insert the given value into 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 _Tp& __x)
  {
    size_type __n = __position - begin();
    if (_M_finish != _M_end_of_storage && __position == end()) {
      _Construct(_M_finish, __x);
      ++_M_finish;
    }
    else
      _M_insert_aux(iterator(__position), __x);
    return begin() + __n;
  }

  /**
   *  @brief  Inserts an empty element into the vector.
   *  @param  position  An iterator that points to the element where empty
   *                    element should be inserted.
   *  @param  x  Data to be inserted.
   *  @return  An iterator that points to the inserted element.
   *
   *  This function will insert an empty element into 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)
  {
    size_type __n = __position - begin();
    if (_M_finish != _M_end_of_storage && __position == end()) {
      _Construct(_M_finish);
      ++_M_finish;
    }
    else
      _M_insert_aux(iterator(__position));
    return begin() + __n;
  }

  // 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 __val, __true_type)
    { _M_fill_insert(__pos, static_cast<size_type>(__n), static_cast<_Tp>(__val)); }

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

  /**
   *  @brief  Inserts a number of copies of given data into the vector.
   *  @param  position  An iterator that points to the element where data
   *                    should be inserted.
   *  @param  n  Amount of elements to be inserted.
   *  @param  x  Data to be inserted.
   *
   *  This function will insert a specified number of copies of the given data
   *  into 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.
  */
  void insert (iterator __pos, size_type __n, const _Tp& __x)
    { _M_fill_insert(__pos, __n, __x); }

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

  /**
   *  @brief  Removes last element from vector.
   *
   *  This is a typical stack operation. It allows us to shrink the vector by
   *  one.
   *
   *  Note that no data is returned and if last element's data is needed it
   *  should be retrieved before pop_back() is called.
  */
  void pop_back() {
    --_M_finish;
    _Destroy(_M_finish);
  }

  /**
   *  @brief  Remove element at given position
   *  @param  position  Iterator pointing to element to be erased.
   *  @return  Doc Me! (Iterator pointing to new element at old location?)
   *
   *  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 responsibilty.
  */
  iterator erase(iterator __position) {
    if (__position + 1 != end())
      copy(__position + 1, end(), __position);
    --_M_finish;
    _Destroy(_M_finish);
    return __position;
  }

  /**
   *  @brief  Remove a range of elements from a vector.
   *  @param  first  Iterator pointing to the first element to be erased.
   *  @param  last  Iterator pointing to the last element to be erased.
   *  @return  Doc Me! (Iterator pointing to new element at old location?)
   *
   *  This function will erase the elements in the given range 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 responsibilty.
  */
  iterator erase(iterator __first, iterator __last) {
    iterator __i(copy(__last, end(), __first));
    _Destroy(__i, end());
    _M_finish = _M_finish - (__last - __first);
    return __first;
  }

  /**
   *  @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 _Tp& __x) {
    if (__new_size < size())
      erase(begin() + __new_size, end());
    else
      insert(end(), __new_size - size(), __x);
  }

  /**
   *  @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 the vector is extended and new elements
   *  are left uninitialized.
  */
  void resize(size_type __new_size) { resize(__new_size, _Tp()); }

  /**
   *  Erases all elements in vector.  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 responsibilty.
  */
  void clear() { erase(begin(), end()); }

protected:

  template <class _ForwardIterator>
  pointer _M_allocate_and_copy(size_type __n, _ForwardIterator __first,
                                               _ForwardIterator __last)
  {
    pointer __result = _M_allocate(__n);
    try {
      uninitialized_copy(__first, __last, __result);
      return __result;
    }
    catch(...)
      {
	_M_deallocate(__result, __n);