Rust reimplementation of the simple and fast LRU cache by Dominic Tarr found here: https://github.com/dominictarr/hashlru
let HLRU = HashLRU::new(100);
HLRU.set(key, value);
let new_value: usize;
match HLRU.get(key) {
Ok(v) => new_value = v,
None => {}
}