Can somebody point me to some documentation on how to use the Arena class? I can only find one mention of it in the docs here. https://kotlinlang.org/docs/mapping-struct-union-types-from-c.html#create-struct-and-union-as-cvaluesref-lt-t-gt I would like to understand the difference between it and using nativeHeap.

The main difference is that Arena keeps track of everything you allocate with it. You can call Arena#close() to free everything it’s allocated. If using nativeHeap, you need to free everything individually.