fn double<T>(a: &T) -> [T] { ret [a] + [a]; }

fn double_int(a: int) -> [int] { ret [a] + [a]; }

fn main() {
    let d = double(1);
    assert (d[0] == 1);
    assert (d[1] == 1);

    d = double_int(1);
    assert (d[0] == 1);
    assert (d[1] == 1);
}