(public) Inheritance in real-world code

[Dwigt]

I'm trying to learn C++ and I've been reading through the C++ FAQ Lite about public inheritance, but I would really like to see some examples. How is this stuff used in the real world? What do "base class" and "derived class" objects look like? And I don't want to see some simple little five lines of code about a Vehicle and a Car; I want the real stuff. How many member functions do they normally have? What kinds of open source/sourceforge projects out there display inheritance? I'm especially irked with questions 19.8 and 19.9 where he says that we're supposed to create a "protected interface," but then he goes on this rant about positive ROI. Spare me the business lecture and give me a couple good examples. Because I'm really not getting this.

[Telion]

The IOstream library uses inheritance extensively. Everything derives from ios_base. Classes istream and ostream inherit from ios, and iostream inherits from both of those. The various fstreams and stringstreams inherit from the normal stream classes.