Derived classes in C - What is your favorite method?

Question

In my experience in object oriented C programming I have seen two ways to implement derived classes.

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First Method, have a definition of the pa

Answer 1

The second way has the advantage of typesafety with inherited methods. If you want to have a method foo(struct parent_class bar) and call it with foo((struct parentclass) derived_class), this will work correctly. The C-Standard defines this. Thus, I'd generally prefer method #2. In general, it is guaranteed that casting a structure to its first member will result in a struct containing the data of the first member of the struct, no matter how memory is laid out.