use std::collections::HashMap;

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

fn main() {
    let mut factory = HashMap::<usize, V>::new();
    let mut collect = HashMap::<&V, usize>::new();
    factory.insert(1, V{});
    match factory.get(&1) {
        None => (),
        Some(v) => {
            collect.insert(&v, 41);
        }
    }
    println!("{:?}", collect);
}