Attempt at List type using Rust std::rc::Rc

intListRc.rs

// Functional-style integer lists
// Compile with "rustc -o intlistRc intlistRc.rs"

use std::rc::Rc;

enum IntList {
    Empty,
    Cons(int, Rc<IntList>),
    List(~Vector<Rc<IntList>>)
}

fn length(l: &IntList) -> uint {
    match *l {
        Empty => 0,
        //Cons(_, ref rest) => 1 + length(&*rest), // expected `&IntList` but found `&std::rc::Rc<IntList>`
        //Cons(_, rest) => 1 + length(&*rest), // cannot move out of dereference of `&`-pointer
        Cons(_, ref rest) => 1 + length(&(*rest.borrow())),
        _ => 0,
    }
}

fn sum_list(l: &IntList) -> int {
    match *l {
        Empty => 0,
        Cons(i, ref rest) => i + sum_list(&(*rest.borrow())),
        _ => 0,
    }
}

fn main()
{
    let l1 = Rc::new(Cons(5, Rc::new(Cons(3, Rc::new(Cons(7, Rc::new(Empty)))))));
    println!("length of l1 is {}", length(l1.borrow()));
    println!("sum of l1 is {}", sum_list(l1.borrow()));

    let l2 = Rc::new(Cons(17, l1));
    println!("length of l2 is {}", length(l2.borrow()));
    println!("sum of l2 is {}", sum_list(l2.borrow()));
}