Re: Inheritance Problem (MSVC 6)

Hi NG,

I have an inheritance like this:

class a_interface
{
virtual bool x() = 0;
};

class a_version_1 : public a_interface
{
virtual bool x() {return true;}
}

class a_version_2: public a_interface
{
virtual bool x() {return false;}
}

class b_interface: public a_interface
{
};

class b_derived: public a_interface, public a_version_1

{
};

class b_interface is never instantiated, only its derived classes are
(there are lots of them, some need a_version1, some a_version2).
When I try to create an instance of b_derived, I get the error "pure
virtual function not defined". Why doesn't it take bool x() from
a_version_1?
Is this a bug in Visual Studio 6?

What can I do about it, if I need to access a_interface from within
b_interface, other than re-implementing a_version_x in every derived
class?