Type Alias UnionToTuple<T, Acc, Last>

UnionToTuple: Acc["length"] extends SafeRecursion
    ? T[]
    : [T] extends [never]
        ? Acc
        : UnionToTuple<Exclude<T, Last>, [Last, ...Acc]>

convert a Union to a Tuple.
usage: UnionToTuple<A | B> = [A, B]