The first readonly tuple.
The second readonly tuple.
type C1 = Tuple.Concat<[1, 2], [3, 4]>; // readonly [1, 2, 3, 4]
type C2 = Tuple.Concat<[], [1]>; // readonly [1]
type C3 = Tuple.Concat<[1], []>; // readonly [1]
type C4 = Tuple.Concat<readonly number[], readonly string[]>; // readonly (number | string)[]
type C5 = Tuple.Concat<[1], readonly number[]>; // readonly [1, ...number[]]
Concatenates two readonly tuples
AandB. General (non-tuple) arrays are also supported; concatenating two general arrays yields a general readonly array of the union of the element types.