I want to create a set of classes like shown below:

  
class InputDevice
{
  ....
};

class JOYSTICK : public InputDevice
{
  protected:
    LPINPUTDEVICE2 device;
  ....
};

///////////////////////////////////////////////

///////////////////////////////////////////////

// Force Feed-back supported joystick.

// If Force FeedBack is not supported by the 

// Joystick, default to JOYSTICK class behavior.

// 

class FEEDBACK : public JOYSTICK
{
  protected:
    LPINPUTDEVICE7 device;
  ....
};

  

Currently I have a LPINPUTDEVICE2 device value and added an LPINPUTDEVICE7 feedback value to the FEEDBACK version. Is there a way to do what I illustrated above? Regards, Jumpster Note: I am posting in two-forums because I don''t know if the solution would be DX specific or C++ general.

Perhaps I am asking the wrong question here?

Let me try again:

I have a base class with a member variable of type "A". I want to inherit from that class, keep the same member variable name but change it to type "B".

Can that be done? If so, how?

Regards,
Jumpster

Yeah, I knew you could to that but I wanted to keep from having to call the QueryInterface() everytime I wanted to use that variable. Constant calling has to be a bottleneck of sorts.

Ultimately, I have created a new variable:

LPINPUTDEVICE7 feedback_joy;

and call QueryInterface() once and store the result in that value. Then I do this...

if (feedback_joy != NULL)
{
device->Release();
device = NULL;
}

that way, only one value is actually going to be used.

Thanks for your input. I appreciate it.

Regards,
Jumpster