Type Alias TupleUnion<ARR1, ARR2, N>

TupleUnion: N extends number
    ? UnionKnown<ARR1[N], ARR2[N]> extends undefined | never
        ? []
        : [
            UnionKnown<ARR1[N], ARR2[N]>,
            ...TupleUnion<ARR1, ARR2, IncrementNumber[N]>,
        ]
    : []

create an element-wise intersection between two tuples. note that the intersection any & T does not produce T for some reason unfortunately.

type A = TupleUnion<[number, unknown, string, boolean], [5, number, string, any, 99]>
// A === [number, number, string, boolean>, undefined | 99]