TypeScript spread operator for 2 tuple types

Ninth challenge is Concat

Sometimes it's useful to collect 2 tuples' elements in one tuple, like Array.prototype.concat.

Using spread for Tuple types

2 changes were introduced in TypeScript 4.0:

1. Variadic Tuple Types
2. You can use spread anywhere in a tuple, not just an end

So let's try it all together:

Here we have an error A rest element type must be an array type, let's add Generic Constrains to allow only arrays:

This is it 🚀

Don't forget to have a look at Playground ⏯