class Encapsulator
{
  protected:
    int i;
  public:
    Encapsulator(int v) : i(v) {}
};

Encapsulator f(int x) { return x + 2; }

#include <iostream>
int main(void)
{
    Encapsulator e = f(7);
    // forbidden: std::cout << e.i << std::endl;
    int Encapsulator::*pi = &Encapsulator::i;
    std::cout << e.*pi << std::endl;
}