Thread: Friend cannot inherit from private subclass

I am trying to inherit a subclass, which is declared as a private member of another class. Although the Friend is declared as a friend of Class, my compiler spits out the following error:

Class.h:5: error: ‘class Class::SubClass’ is private
Friend.h:3: error: within this context

Could anyone explain to me what I am getting wrong here? BTW, the compiler I am using is gcc 4.1.2.

Class.h, the class with the private subclass that I am trying to inherit:

Code:

class Class
{
    private:
        class SubClass
        {
            public:
                void A();
        };
    public:
        friend class Friend;
};

Friend.h, the class that is trying to inherit the private subclass:

Code:

#include "Class.h"

class Friend: public Class::SubClass
{
};