main() {
    let v: u64;
    let ref_v: &mut u64;
    v = 0;
    *(&mut v) = 5;
    ref_v = &mut v;
    assert(*copy(ref_v) == 5, 42);
    *(copy(ref_v)) = 42;
    assert(*move(ref_v) == 42, 42);
    assert(copy(v) == 42, 42);
    return;
}