fn do_a_thing(i int) ?int {
	if i < 0 {
		return error("can't be negative")
	}
	if i == 0 {
		return none
	}
	return i
}

fn test_match_error_to_none() {
	i := 0
	if r := do_a_thing(i) {
		println(r)
	} else {
		match err {
			none {
				assert true
			}
			else {
				assert false
			}
		}
	}
}