rust/src/test/run-pass/maybe-mutable.rs

// -*- rust -*-
fn len(v: [mutable? int]) -> uint {
    let i = 0u;
    for x: int  in v { i += 1u; }
    ret i;
}

fn main() {
    let v0 = ~[1, 2, 3, 4, 5];
    log len(v0);
    let v1 = ~[mutable 1, 2, 3, 4, 5];
    log len(v1);
}