#include <iostream>
 
using namespace std;
 
struct A {
  int a;
};
 
struct B {
  int b;
};
 
struct C: A, B {
  int c;
};
 
 
struct Base {
  virtual B* func() = 0;
  virtual ~Base() = default;
};
 
struct Derived: Base {
  C* func() {
    auto p = new C;
    cout << p << endl;
    return p;
  }
};
 
 
int main() {
  Base* pb = new Derived;
  cout <<  pb->func() << endl;
  // the outputed two addresses are different.
  // how is the pointer cast (adding some offset) achieved?
}
 

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