C库宏 - va_arg()

#include <stdarg.h>

#include <stdio.h>



int sum(int, ...);



int main () {

   printf("Sum of 15 and 56 = %d\n",  sum(2, 15, 56) );

   return 0;

}



int sum(int num_args, ...) {

   int val = 0;

   va_list ap;

   int i;



   va_start(ap, num_args);

   for(i = 0; i < num_args; i++) {

      val += va_arg(ap, int);

   }

   va_end(ap);



   return val;

}