Can I call a base class's virtual function if I'm overriding it?

Say I have classes Foo and Bar set up like this:

class Foo
{
public:
    int x;

    virtual void printStuff()
    {
        std::cout << x << std::endl;
    }
};

class Bar : public Foo
{
public:
    int y;

    void printStuff()
    {
        // I would like to call Foo.printStuff() here...
        std::cout << y << std::endl;
    }
};

As annotated in the code, I'd like to be able to call the base class's function that I'm overriding. In Java there's the super.funcname() syntax. Is this possible in C++?


Solution 1:

The C++ syntax is like this:

class Bar : public Foo {
  // ...

  void printStuff() {
    Foo::printStuff(); // calls base class' function
  }
};

Solution 2:

Yes,

class Bar : public Foo
{
    ...

    void printStuff()
    {
        Foo::printStuff();
    }
};

It is the same as super in Java, except it allows calling implementations from different bases when you have multiple inheritance.

class Foo {
public:
    virtual void foo() {
        ...
    }
};

class Baz {
public:
    virtual void foo() {
        ...
    }
};

class Bar : public Foo, public Baz {
public:
    virtual void foo() {
        // Choose one, or even call both if you need to.
        Foo::foo();
        Baz::foo();
    }
};

Solution 3:

Sometimes you need to call the base class' implementation, when you aren't in the derived function...It still works:

struct Base
{
    virtual int Foo()
    {
        return -1;
    }
};

struct Derived : public Base
{
    virtual int Foo()
    {
        return -2;
    }
};

int main(int argc, char* argv[])
{
    Base *x = new Derived;

    ASSERT(-2 == x->Foo());

    //syntax is trippy but it works
    ASSERT(-1 == x->Base::Foo());

    return 0;
}