Is there a way to determine a member offset at compile time?

Question

I\'m finding I\'m spending a lot of time trying to determine member offsets of structures while debugging. I was wondering if there was a quick way to determine the offset

Answer 1

This should do:

#define OFFSETOF(T, m) \
  (size_t) (((char *) &(((T*) NULL)->m)) - ((char *) ((T*) NULL)))

Call it like this:

size_t off = OFFSETOF(struct s, c);