pub fn back(&self) -> Option<&A::Item> {
        if !self.is_empty() {
            Some(&self[self.len() - 1])
        } else {
            None
        }
    }
/// Provides a reference to the back element, or `None` if the sequence is
/// empty.
///
/// # Examples
///
/// ```
/// use arraydeque::ArrayDeque;
///
/// let mut buf: ArrayDeque<[_; 2]> = ArrayDeque::new();
///
/// buf.push_back(1);
/// buf.push_back(2);
///
/// assert_eq!(buf.back(), Some(&2));
/// ```
Provides a reference to the back element, or `None` if the sequence is
empty.
Provides a reference to the back element or ` None ` if the sequence is empty .
pub fn back(&self) -> Option<&A::Item> {
        if !self.is_empty() {
            Some(&self[self.len() - 1])
        } else {
            None
        }
    }
pub fn back ( & self ) -> Option < & A :: Item > { if ! self . is_empty ( ) { Some ( & self [ self . len ( ) - 1 ] ) } else { None } }
Provides a reference to the back element, or `None` if the sequence is
empty.
Provides a reference to the back element or ` None ` if the sequence is empty .
&self
examples
```
use arraydeque::ArrayDeque.

let mut buf: ArrayDeque<[_; 2]> = ArrayDeque::new().




` ` ` use arraydeque :: ArrayDeque . let mut buf : ArrayDeque< [ _ ; 2 ] > = ArrayDeque :: new () .