Cell<T>

What is Cell<T>?

It is a shareable mutable container which means shared references can be mutable. The references rules do not permit this, but there are situations wherein we need multiple mutable references. A good example would be a Doubly Linked List wherein we need two mutable references to each node in the list.

What is interior mutability?

Interior mutability means enabling mutation inside an immutable struct. Cell<T> implements interior mutability, here’s how Cell<T> implements it:

pub fn replace(&self, val: T) -> T

The replace function takes an immutable reference to Cell<T> types and a value T and replaces the contained value inside the Cell<T>.

How is this possible?

This can be slightly confusing because we are taking a shared ...