pub fn main(world: World) -> Void raises {
    var filled: [8]u8 = [7_u8; 8]
    var listed: [4]u8 = [1, 2, 3, 4]
    filled[0] = listed[3]
    if filled[0] == 4 {
        check world.out.write("fixed array lengths ok\n")
    }
}