Can sizeof return 0 (zero)

Question

Is it possible for the sizeof operator to ever return 0 (zero) in C or C++? If it is possible, is it correct from a standards point of view?

Answer 1

Empty structs, as isbadawi mentions. Also gcc allows arrays of 0 size:

int a[0];
sizeof(a);

EDIT: After seeing the MSDN link, I tried the empty struct in VS2005 and sizeof did return 1. I'm not sure if that's a VS bug or if the spec is somehow flexible about that sort of thing