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

That will work in this particular case. The foo field in the first member of both structures and hit has the same type. However this is not true in the general case of fields within a struct (that are not the first member). Items like alignment and packing can make this break in subtle ways.