Question

I have the the following classes:

class Base
{
public:
    Base() { x = 3; }
    int x;
    virtual void foo() {};
};

class Med1 : public virtual Base
{
public:
    int x;
    Med1() { x = 4; }
    virtual void foo() {};
};

class Med2 : public virtual Base
{
public:
    virtual void goo() {};
    virtual void foo() {};
};

class Der : public Med1, public Med2
{
public:
    Der() {}
    virtual void foo() {};
    virtual void goo() {};
};

And the following code:

Base* d = new Der;
d->foo();
cout << d->x;

Output:

 3

Why is that? Med1 constructor is called after Base constructor. I’m guessing it’s setting Med1::x, and not Base::x, but why is Der::x the same as Base::x and not Med1::x. Why is there no ambiguity?

Answer 1

d is a pointer to Base, so d->x refers unambiguously to Base::x. There would only be an ambiguity if it were a pointer to Der.