Question

Let’s say I have the following classes:

class A {
 public:
  virtual void foo() {
    bar();
  }

 protected:
  virtual void bar() {
    // Do stuff
  }
}

class B : public A {
 protected:
  virtual void bar() {
    // Do other stuff
  }
}

If I have an instance of B and call the foo method, which bar method would get called? And is this compiler specific?

Thanks

Answer 1

The A::foo will call B::bar if you have an instance of B. It does not matter if the instance is referenced through a pointer or a reference to a base class: regardless of this, B‘s version is called; this is what makes polymorphic calls possible. The behavior is not compiler-specific: virtual functions behave this way according to the standard.