For things like classes that aren't going to be created and destroyed quickly it likely is best to just use a Rc. Then you know it will be available and don't n

For things like classes that aren't going to be created and destroyed quickly it likely is best to just use a Rc. Then you know it will be available and don't need to bother with lifetimes. Of course there is a good chance that you will eventually want a VM-scoped lifetime for something else so maybe it is best to just start now.