enum payload:
    empty
    numbers(items: [i32, 3])
    object(item: thing)
struct thing:
    value: i32
func make(x: i32) -> result<payload, string>:
    if x < 0:
        return Err("negative")
    return Ok(payload.numbers([x, 2, 3]))
func entry(x: i32) -> i32:
    var a: [payload] = [payload.empty, payload.object(thing(value = 5)), payload.numbers([1, 2, 3])]
    var copied = a[2]
    if copied is payload.numbers(var values):
        values[0] = 99
    var result = make(x)
    match result:
        Ok(payload.numbers(var values)):
            return values[0] + a.count as i32
        _:
            return -1