Struct Deque

pub struct Deque<T> { /* private fields */ }

A double-ended queue (abbreviated to deque), for which elements can be added or remove from both back and front ends.

Underneath the hood, this Deque uses a contiguous memory block as a ring buffer to store values.

References:

• Rust Standard Library: std::collections::VecDeque
• Wikipedia: Circular buffer

Implementations

impl<T> Deque<T>

pub fn new() -> Self

Constructs a new, empty Deque<T>.

For convenience, the deque initially allocates a region of a single T.

pub fn push_front(&mut self, elem: T)

Prepends the given element value to the beginning of the container.

Parameters

• elem - The element to prepend.

Complexity

Constant.

pub fn push_back(&mut self, elem: T)

Appends the given element value to the end of the container.

Parameters

• elem - The element to append.

Complexity

Constant.

pub fn pop_front(&mut self) -> Option<T>

Removes and returns the first element of the container. If there are no elements in the container, return None.

Complexity

Constant.

pub fn pop_back(&mut self) -> Option<T>

Removes and returns the last element of the container. If there are no elements in the container, return None.

Complexity

Constant.

pub fn front(&self) -> Option<&T>

Peeks the first element of the container. If there are no elements in the container, return None.

Complexity

Constant.

pub fn back(&self) -> Option<&T>

Peeks the last element of the container. If there are no elements in the container, return None.

Complexity

Constant.

pub fn is_empty(&self) -> bool

Checks whether the container is empty.

Complexity

Constant.

pub fn len(&self) -> usize

Gets the number of elements in the container.

Complexity

Constant.

pub fn iter(&self) -> Iter<'_, T>

Creates an iterator that yields immutable reference of each element.

pub fn iter_mut(&mut self) -> IterMut<'_, T>

Creates an iterator that yields mutable reference of each element.

Trait Implementations

impl<T: Debug> Debug for Deque<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> Drop for Deque<T>

fn drop(&mut self)

Executes the destructor for this type.

impl<T> Index<usize> for Deque<T>

type Output = T

The returned type after indexing.

fn index(&self, index: usize) -> &Self::Output

Performs the indexing (container[index]) operation.

impl<T> IndexMut<usize> for Deque<T>

fn index_mut(&mut self, index: usize) -> &mut T

Performs the mutable indexing (container[index]) operation.

impl<'a, T> IntoIterator for &'a Deque<T>

type Item = &'a T

The type of the elements being iterated over.

type IntoIter = Iter<'a, T>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<'a, T> IntoIterator for &'a mut Deque<T>

type Item = &'a mut T

The type of the elements being iterated over.

type IntoIter = IterMut<'a, T>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<T> IntoIterator for Deque<T>

type Item = T

The type of the elements being iterated over.

type IntoIter = IntoIter<T>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.