This is only partly correct. It’s generally encouraged to use value types (or the up coming move only types) unless you actually want the reference semantics or

This is only partly correct. It’s generally encouraged to use value types (or the up coming move only types) unless you actually want the reference semantics or you are interoping with objc apis on Darwin. If you ever watch talks from folks like Dave A. Who wrote the stdlib, he says he only ever uses arc types as a mechanism to enforce COW for the stdlib types and containers.