Maybe it’s worth mentioning import vs #include, and particularly

Under “Inheritance”, there’s a missing semicolon after ~Widget(). Also, Widget’s destructor should be qualified as virtual (as should Frob’s – and IWidget’s).

In the right column, you’ve slipped a System.Out.println() into the C++ code. Also, it may be that correctly defined iterators will have a suitably overloaded operator-> so the (*i). may rightly be i-> … I don’t recall for sure though.

Also, maybe something on pass by value vs pass by reference.

std::endl instead of std::end

I thought the vector iteration didn’t have a header at first pass, since I was reading it as three columns down rather than across. Also I didn’t know that C++ had System.out.println

For the inheritance and interface examples, is it worthwhile putting the constructors in?

It looks good so I bookmarked it for myself.

Your students might find it useful.