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 code I worked with used the first method.

The only two reasons I can think of for using the first method is:

1. Saves you some cycles because you will be doing one less de-referencing
2. When you cast the derived class pointer to the parent class, i.e. (struct parent_class *)ptr_my_derived_class , you know 100% what the expected result will be.

I prefer the first method because you can cast the derived class pointer to the parent class without any worries.

Can you do the same thing with the second method? ( It seems like you would have to jump through a hoop or two to get the same end result )

If you can do the same with method 2, then I think both methods would be equal.