Struct Stack 

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

Implementations

impl<T> Stack<T>

pub fn new() -> Self

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

pub fn pop(&mut self) -> Result<T, &str>

In pop function, we trying to:

• check if the list is empty, so we use enum Option, it can either be Some(T) or None
  • if it’s empty, return None
  • if it’s not empty
    • remove the head of the list
    • remove its elem
    • replace the list’s head with its next
    • return Some(elem), as the situation if need

so, we need to remove the head, and return the value of the head

pub fn is_empty(&self) -> bool

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

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

pub fn into_iter_for_stack(self) -> IntoIter<T>

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

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

Trait Implementations

impl<T> Default for Stack<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T> Drop for Stack<T>

The drop method of singly linked list. There’s a question that do we need to worry about cleaning up our list? As we all know the ownership and borrow mechanism, so we know the type will clean automatically after it goes out the scope, this implement by the Rust compiler automatically did which mean add trait drop for the automatically.

So, the complier will implements Drop for List->Link->Box<Node> ->Node automatically and tail recursive to clean the elements one by one. And we know the recursive will stop at Box https://rust-unofficial.github.io/too-many-lists/first-drop.html

As we know we can’t drop the contents of the Box after deallocating, so we need to manually write the iterative drop

fn drop(&mut self)

Executes the destructor for this type.