📄 stl_vector.h
字号:
*/
iterator
begin() { 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 { 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() { 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 { 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()); }
// [23.2.4.2] capacity
/** Returns the number of elements in the %vector. */
size_type
size() const { return size_type(end() - begin()); }
/** Returns the size() of the largest possible %vector. */
size_type
max_size() const { return size_type(-1) / sizeof(value_type); }
/**
* @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())
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
* default-constructed.
*/
void
resize(size_type __new_size) { resize(__new_size, value_type()); }
/**
* Returns the total number of elements that the %vector can
* hold before needing to allocate more memory.
*/
size_type
capacity() const
{ return size_type(const_iterator(this->_M_impl._M_end_of_storage) - begin()); }
/**
* 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().)
*/
reference
operator[](size_type __n) { return *(begin() + __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().)
*/
const_reference
operator[](size_type __n) const { return *(begin() + __n); }
protected:
/// @if maint Safety check used only from at(). @endif
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); }
// [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)
{
std::_Construct(this->_M_impl._M_finish, __x);
++this->_M_impl._M_finish;
}
else
_M_insert_aux(end(), __x);
}
/**
* @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;
std::_Destroy(this->_M_impl._M_finish);
}
/**
* @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);
/**
* @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.
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -