use std::collections::HashMap;
use std::sync::Arc;

#[derive(PartialEq, Eq, Hash, Debug)]
struct V {}

fn main() {
    let v1 = V {};
    let v2 = V {};

    let mut collect = HashMap::<&Arc<V>, usize>::new();

    let av1 = Arc::new(v1);
    let av2 = Arc::new(v2);

    collect.insert(&av1, 15);
    collect.insert(&av2, 42);

    println!("{:?}", collect.get(&av1));
}