#include <iostream>
using namespace std;
class Base
{
private : int y; 
public:
   void SetData(int value) {
	   y = value; 
	   cout<< y; 
	   };
};

void (Base::*proxy)(int) = &Base::SetData; 
int main(void)
{
   Base base;
   // Initialize pointer.
  // base.SetData(5); // Set initial value for private data.
   cout<<"\n using a pointer : "; 
   (base.*proxy)(20); // Call member function through pointer.
   return 0;
}