Update:

This project is unsound due to the violation that UnsafeCell is the only legitimate way to get interior mutability.

See Interior Mutability

A rust implementation of AVL Tree.

I start this project for a better understanding of the unsafe part of rust, so I use Option<NonNull<Node>> instead of Option<Box<Node>>. As a result, there are a lot of unsafe blocks whenever it needs to access the child or parent.

It's still under construction.

use avltree::AVLTree;

let mut avl = AVLTree::<i32, i32>::new();
avl.insert(1, 42);
assert_eq!(avl.get(&1), Some(&42));
avl.delete(&1);

It's slightly faster than some other safe rust alternatives I found on github. However, it's still nearly four times slower than std::collections::BTreeMap and the C version AVL tree implemantation avlmini.

On my computer, inserting 10,000,000 random keys.

avltree: ~15s

some-other-avltree-A: ~18s

some-other-avltree-B: ~16s

some-other-unsafe-avltree-C: ~13.5s

BTreeMap|avlmini|linux_rbtree: ~4s