On Thu, 17 Jan 2019 12:15:20 -0800, H. S. Teoh wrote: > A better approach might be to make TBottom* always equal to null -- > i.e., it's always illegal to dereference it because no instances of > TBottom can exist. Dereferencing TBottom* would have to be rewritten as `assert(false);` to make this type of illegal work with generic code.