Effective C++: discouraging protected inheritance?

Question

I was reading Scott Meyers\' Effective C++ (third edition), and in a paragraph in Item 32: Make sure public inheritance is \"is-a\" on page 151 he make

Answer 1

Yes and no. I myself think that protected inheritance is a bad feature too. It basicly imports all the base class's public and protected members as protected members.

I usually avoid protected members, but on the lowest levels requiring extreme efficiency with a compiler with bad link-time optimization they are useful. But everything built on that shouldn't be messing with the original base class's (data) members and use the interface instead.

What I think Scott Meyer is trying to say, is that you can still use protected inheritance if it solves a problem, but make sure to use comments to describe the inheritance because it's not semantically clear.