Question on dynamic casting scope

[Philippe Bouchard]

The following program:
#include <iostream>
int main();
struct A
{
  virtual ~A() {}
};
struct B
{
  virtual ~B() {}
};
struct O : A, private B
{
  friend int main();
  virtual ~O() {}
};
int main()
{
  using namespace std;
  A * p = new O;
  cout << "A * = " << dynamic_cast<A *>(p) <<
endl;
  cout << "B * = " << dynamic_cast<B *>(p)
<< endl;
  cout << "O * = " << dynamic_cast<O *>(p)
<< endl;
}
Outputs:
A * = 0x8049fd0
B * = (nil)
O * = 0x8049fd0
Notice:
If I the inheritance of B into O becomes public, the address of B *
becomes 0x8049df4.
Question:
I was wondering why friendship is not affecting dynamic casting scope.
Thank you.
 
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