Polymorphism?

[Sam Finch]

I want a class that I can use inside another class, but I want it to be a combination of 2 different classes. both would have the same functions but somewhere in the constructor I'd like to specify which one the class is using.
say my 2 classes are

class A
{

public:

    A(void);
    long Fn(void);

};

A::A(void)
{
}

long A::Fn(void)
{

     return 10;

}

class B
{

long m_value;

public:

    B(long Value);
    long Fn(void);

};

B::B(long Value)
{
m_value = Value;
}

long B::Fn(void)
{

     return m_value;

}

Now say I want a class C with an overloaded contructor, if I don't include a value in the constructor it inherits a class A, if I do it inherits a class B.

Is that possible?

How about defining two different constructors and depending on which one you use, you can create an instance of the class that is appropriate.
Something like
class C
{
public:
C(void)
{
A a;
}
C(int in)
{
B a;
}
};

[Sam Finch]

Right, I was Kinda Hoping on Inheriting them rather than passing all the properties through(I'm including oversimple examples here) oh well