Track data access to stl container

With protected inheritance, you still have to wrap everything, since otherwise nobody can access the vector member that you're trying not to wrap.

With public inheritance, you end up with the slicing problem: someone can just implicitly cast your type to std::vector<...>& and bypass your code without even realizing that they're doing it.

With C++ as it stands today, wrapping is pretty much your only real choice. C++17 may offer respite via operator. (aka smart references, aka proxy objects) but that isn't available even in preview form yet as it's still undergoing design and debate in the committee.

You could, but keep in mind that none of the methods on vector are virtual, including dtor, so beware if you and up passing your derived class to functions that will operate on std::vector. There is enough discussions on the web that you can search for to get more info.