Thread: Why wont this compile:

What is wrong with this code:

Code:

#include <iostream>

using namespace std;

class AbstractClass
{
    public:
        virtual void Func();
        virtual void Func(int x) = 0;
};

class DerivedClass : public AbstractClass
{
    virtual void Func(int x);
};

void AbstractClass::Func()
{
    Func(3);
}

void DerivedClass::Func(int x)
{
    cout << " x is " << x << "\n";
}

int main(void)
{
    DerivedClass d;
    d.Func();
}

When I compile it it says no matching function call to DerivedClass::Func().

If I change the following it works:

Code:

int main(void)
{
    AbstractClass *d = new DerivedClass;
    d->Func();
    delete d;
}

Or, if I change the name Func(int x) to Foo(int x) it works. Why cant I overload Func with a pure virtual function?

Thanks,
Bob

virtual is really a red herring here. Even if you had

Code:

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

class B : public A {
    public:
        void foo(int x);
};

//later
B bar;
bar.foo(); //won't work

The "new" foo in class B will hide the "old" foo in class A.

....