I've got this piece of code. It appears to dereference a null pointer here, but then bitwise-ANDs the result with unsigned int. I really don't understand the whole part. What is it intended to do? ...

Linux's stddef.h defines offsetof() as: #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) whereas the Wikipedia article on offsetof() (http://en.wikipedia.org/wiki/Offsetof) ...

Is there a way of finding the offset of a member of a structure at compile-time? I wish to create a constant containing the offset of a structure member. In the following code the offsetof() macro ...

What is the purpose of __builtin_offsetof operator (or _FOFF operator in Symbian) in C++? In addition what does it return? Pointer? Number of bytes?