Adapters store unique_ptr members to the C++ implementation of their respective classes. They should only be accessed through Handle<>, never copied or moved. Deleting copy and move constructors/assignment ensures the unique_ptr remains valid for the adapter's lifetime, so we can always safely dereference it.

We should ensure that all adapters:
1. Include a tassert that the contained unique_ptr is not a nullptr at construction-time
2. Delete their move and copy constructors