Reference counting is a garbage-collection system like the others (and if you are going to use a garbage-collection system, you can for many usecases do better than reference counting).
> Reference counting is a garbage-collection system like the others
Reference counting is a form of automated memory management which can easily be integrated and used in a manually-managed system, and can be used for a specific subset of the in-memory structures (again see shared_ptr). Not so for more complex garbage collection systems which tend to interact badly with manual or ownership-based memory management. Putting the lie to your assertion that the only way to implement sharing in a non-GC language is "gratuitous copying".
