fn main() {
    println!("Hello, world!");
}

struct Node<'a> {
    name: &'a str,
}

fn find_or_insert<'a>(nodes: &'a mut Vec<Node<'a>>, name: &'a str) -> &'a Node<'a> {
    match nodes.iter().position(|n| n.name == name) {
        Some(n) => return &nodes[n],
        None => {
            let n = Node {
                name,
            };
            nodes.push(n);
            nodes.last().unwrap()
        }
    }
}