RefCell<T>

What is RefCell<T>

RefCell<T> is also a shareable mutable container like Cell<T>. The compiler enforces the rules of references for Cell at compile time which is not very flexible. Therefore, RefCell<T> gives us flexibility with dynamic rule checking, meaning borrows are tracked during runtime.

How dynamic borrow checking works?

To understand this, Let’s have a look at RefCell<T> definition in the standard library,

pub struct RefCell<T: ?Sized> {
    borrow: Cell<BorrowFlag>,
    // Stores the location of the earliest currently active borrow.
    // This gets updated whenever we go from having zero borrows
    // to having a single borrow. When a borrow