trick to access a private member of class through its object

#include < iostream >

using namespace std;

class Base{
      public: virtual void fun()=0;
};

class derived:private Base{
 private: void fun(){
  cout < < "accessing private method" < < endl;
 }
};

int main(){
    Base *base;
    derived *dptr = new derived();
    base = (Base *)dptr;
    base- > fun();
    return 0;
}