// En C++

#include <iostream>
#include <math.h>

using namespace std;

class X {
 public:
  int i;
  double f(double a);
};

double X::f(double a)
{
 return sin(a);
}

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

 x.i = 2;

 v = x.f(M_PI);

 cout << "x.i=" << x.i << endl;
 cout << "v=" << v << endl;

 return 0;
}