struct EmptyStruct {
    b []int = [1, 2, 3]
}

fn encode_array[T](val []T) []int {
    return val
}

fn encode_struct[T](val T) []int {
    $if T is $struct {
        $for field in T.fields {
            $if field.is_array {
                return encode_array(val.$(field.name))
            }
        }
    }
    return [0]
}

fn encoder() []int {
    return encode_struct(EmptyStruct{})
}

fn test_main() {
    assert encoder() == [1, 2, 3]
}