C库宏 - offsetof()

#include <stddef.h>

#include <stdio.h>



struct address {

   char name[50];

   char street[50];

   int phone;

};



int main () {

   printf("name offset = %d byte in address structure.\n",

   offsetof(struct address, name));



   printf("street offset = %d byte in address structure.\n",

   offsetof(struct address, street));



   printf("phone offset = %d byte in address structure.\n",

   offsetof(struct address, phone));



   return(0);

}