I have a need to obtain a unique identifier for a type of NSManagedObject I've created. It needs to be available as soon as the object has been created, never change, and be completely unique.
This rules out the NSManagedObjectID, as this can change when the context is saved. I believe the -hash method could be non-unique if my objects have the same properties.
I'd really like to avoid creating an otherwise useless uniqueIdentifier UUID field on the entity as this seems wasteful and messy. Is there an accepted best practice here?