1  #include <stdarg.h>
       2  
       3  main ()
       4  {
       5    double f (int x, ...)
       6      {
       7        va_list args;
       8        double a;
       9  
      10        va_start (args, x);
      11        a = va_arg (args, double);
      12        va_end (args);
      13        return a;
      14      }
      15  
      16    if (f (1, (double)1) != 1.0)
      17      abort ();
      18    exit (0);
      19  }