Trees gone wrong

looks_scary.rs

enum Tree<A> {
    Leaf(A),
    Node(Box<Tree<(A, A)>>)
}

fn size<A>(t : &Tree<A>) -> int {
    match t {
        &Leaf(_) => 1,
        &Node(box ref t) => size(t)
    }
}

fn main () {}

// task 'rustc' has overflowed its stack
// Compilation illegal instruction (core dumped) at Fri Nov 14 18:04:13