#include <stdio.h>

int currentYear = 2008;

class Person {
public:
   struct
   {
      operator int ()
      {
         return currentYear - ((Person*)this)->yearOfBirth;
      }
      int operator= (int value)
      {
         ((Person*)this)->yearOfBirth = currentYear - value;
         return value;
      }
   } age;
   int yearOfBirth;
   Person()
   {
      yearOfBirth = 1989;
   }
   void PrintYearOfBirth(void) {
      printf("Year of birth:  %d\n", yearOfBirth);
   }
};

int main(int argc, char *argv[])
{
   Person person;

   printf("Age:  %d\n", (int)person.age);
   person.PrintYearOfBirth();

   person.age = 21;

   printf("Age:  %d\n", (int)person.age);
   person.PrintYearOfBirth();

   return 0;
}