[thinkingkong]

It lets you specify the type of length of an array but it has absolutely no protection other than initialization. For example, you can _easily_ push to an `Array<number>(5)` so... other than initializing by hand with all positional arguments you aren't getting any safety.

[atwood22]

That’s an interesting idea. You could define a custom type that has the type of [number, number] and combine it with Omit to remove methods that allow extending the array.