C++ 多级继承，多态

Question

Suppose i have three classes A, B and C. class B inherits from class A and the inheritance is private whereas class C inherits from B and the inheritance is public. Now class A has a protected function which class C wants to access. So, what must be done in class B to make that protected function available to class C.

Here is the link to the code : http://pastebin.com/9E2sLZzj

Answer 1

The "using" keyword makes a member of an inherited class visible, and resolvable, in the scope of its subclass. So, to make the privately-inherited member available to B 's subclasses:

class A {

protected:

    void foo() {}
};

class B : private A {

protected:

    using A::foo;
};

class C : public B {

    void bar()
    {
        foo();
    }
};

Answer 2

Okay i got the solution This code fragment worked after inserting it into Class B.

int get(){
  return A::get();
}

Not sure what it does though