Does the concept of "an array of exactly 4 elements" exist in the kotlin type system? As an argument to my function.

Size is not a part of the type system in Kotlin. You can pass in an Array, but can’t specify the size. I would make a class called Array4 or something with a constructor that takes in 4 elements.

Went for a

require

instead, not as nice, but should do

If your array required 2 or 3 elements, you could have used

Pair

or

Triple

. But there's no

Quadruple

.