Except that even Apple's ARC is not automatic - try passing the pointer to a GArray, or putting it on a malloc'ed linked list or any other data structure not implemented in Swift or ObjectiveC (provided that you compile objectiveC with the correct build flags).

The point is: you can't leak, you can't end up keeping a reference without incrementing the refcount and you don't events have to worry about any of the refcounting as long as the code you write is sound according to Rust rules.