/* En C et en C++ */

#include <stdio.h>
#include <math.h>

struct X {
  int i;
  double (*f)(double);
};

int main(void)
{
 struct X x;
 double v;

 x.i = 2;
 x.f = &sin;

 v = x.f(M_PI);

 printf("x.i=%d\n",x.i);
 printf("v=%f\n",v);

 return 0;
}