error

tmp/recursive.rs:19:16: 19:38 error: borrowed value does not live long enough
tmp/recursive.rs:19         curr = curr.unwrap().children.find_or_insert(a.clone(), Some(Node::new(a.clone())));
                                   ^~~~~~~~~~~~~~~~~~~~~~
tmp/recursive.rs:15:11: 21:2 note: reference must be valid for the block at 15:10...
tmp/recursive.rs:15 fn main() {
tmp/recursive.rs:16     let v = ~[~"Hello", ~"Tree", ~"World"];
tmp/recursive.rs:17     let mut curr = &mut Some(Node::new(~"Testing"));
tmp/recursive.rs:18     for a in v.iter() {
tmp/recursive.rs:19         curr = curr.unwrap().children.find_or_insert(a.clone(), Some(Node::new(a.clone())));
tmp/recursive.rs:20     }
                    ...
tmp/recursive.rs:19:9: 19:92 note: ...but borrowed value is only valid for the statement at 19:8
tmp/recursive.rs:19         curr = curr.unwrap().children.find_or_insert(a.clone(), Some(Node::new(a.clone())));
                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tmp/recursive.rs:19:16: 19:20 error: cannot move out of dereference of `&mut`-pointer
tmp/recursive.rs:19         curr = curr.unwrap().children.find_or_insert(a.clone(), Some(Node::new(a.clone())));
                                   ^~~~
error: aborting due to 2 previous errors

recursive.rs

extern crate collections;
use collections::hashmap::HashMap;

struct Node {
    data : ~str,
    children : ~HashMap<~str, Option<Node>>,
}

impl Node {
    fn new(data: ~str) -> Node {
        Node{ data: data.clone(), children: ~HashMap::new() }
    }
}

fn main() {
    let v = ~[~"Hello", ~"Tree", ~"World"];
    let mut curr = &mut Some(Node::new(~"Testing"));
    for a in v.iter() {
        curr = curr.unwrap().children.find_or_insert(a.clone(), Some(Node::new(a.clone())));
    }
}