Nodes in Doubly Linked List

A node in a doubly linked list is similar to a node in a singly linked list, but instead of only having one pointer next, it has two pointers: next (a pointer to the next node) and prev (a pointer to the previous node).

In C

typedef struct Node {
    int data;
    struct Node *next;  // Pointer to the next node
    struct Node *prev;  // Pointer to the previous node
} Node;

The prev pointer lets us traverse backwards through the list, which is the main advantage of doubly linked lists.

In Rust?

Yeah imma be honest, I tried to implement this in Rust, but then John Rust (Ferris) broke into my house at 3 AM and told me to stop cuz I was violating every rule known in Rust.

So... for doubly linked lists, no Rust version.

Why Doubly Linked Lists Break Rust

Each node needs both next and prev pointers. But if Node A points to Node B's next, and Node B points to Node A's prev, we'd have circular ownership.

Rust's entire safety model is built on single ownership. Doubly linked lists fundamentally violate this. It is possible to make them work with Rc<RefCell<Node>> or raw pointers, but it's very painful and un-idiomatic.