//# publish
module 0x1.M {
    struct Coin { value: u64 }
    zero(): Self.Coin {
    label b0:
        return Coin { value: 0 };
    }
}

//# run
import 0x1.M;

main() {
    let z: M.Coin;
label b0:
    z = M.zero();
    // invalid assignment
    z = M.zero();
    return;
}