size of a datatype without using sizeof

Question

I have a data type, say X, and I want to know its size without declaring a variable or pointer of that type and of course without using sizeof oper

Answer 1

if X is datatype:

#define SIZEOF(X) (unsigned int)( (X *)0+1 )

if X is a variable:

#define SIZEOF(X) (unsigned int)( (char *)(&X+1)-(char *)(&X) )