Just out of curiosity, why do you care so much about the lifecycle of an object.<p>I can see why you might want to know in the case where you&#x27;re representing an external resource, e.g. an open file, but otherwise, I don&#x27;t see any reason to care about it.<p>In face, with persistent data structures, you <i>can&#x27;t</i> know. The same is true of share (immutable) data with multiple threads. You <i>can&#x27;t</i> know the lifetime.