Tuple<Type?> matches type constraint for tuple with elements of type Type
Parameter isn't required (default to any) in Tuple, but it can be parameterised with a type Type to constraint it
to a specified type (e.g. number):
type NumberTuple = Tuple<number>;
const digits: NumberTuple = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
// error: Type 'string' is not assignable to type 'number'
const first3letters: NumberTuple = ["a", "b", "c"];
// ^^^It's handy to use Tuple without Type as generic type in a function to convert array to a tuple
const asTuple = <Type extends Tuple>(args: Type): Type => args;
const name = asTuple(["<first name>", "<last name>"]);
// ^? [string, string]TS Playground – https://tsplay.dev/W4jgKN