Type alias FlatIterable<T, Depth>

FlatIterable<T, Depth>: {
done: Iterable<T>;
recur: T extends Iterable<infer Inner> ? FlatIterable<Inner, [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][Depth]> : Iterable<T>;
}[Depth extends -1 | 0 ? "done" : "recur"]