Structures and casting in C

Question

I was wondering:

If I have structure definitions, for example, like this:

struct Base {
  int foo;
};

struct Derived {
  int foo; // int foo is comm         


        

Answer 1

The great/bad thing about C is that you can cast just about anything -- the problem is, it might not work. :) However, in your case, it will*, since you have two structs whose first members are both of the same type; see this program for an example. Now, if struct derived had a different type as its first element -- for example, char *bar -- then no, you'd get weird behavior.

* I should qualitfy that with "almost always", I suppose; there're a lot of different C compilers out there, so some may have different behavior. However, I know it'll work in GCC.