void* pointer to object in C++

[byteit101]

I have been at this for some time now, and this won't compile:

(function(int data))
void * MyPointer
if (data=0)
{
     Gyro gy(1);
     MyPointer = &gy;
}
if (data=1)
{
     Ultrasonic gy(1);
     MyPointer = &gy;
}
if (etc...
etc...
(function2(int data2))
if (data2=0)
     return MyPointer->GetValue(); //this produces error: 'void*' is not a pointer-to-object type (:eek:)
etc...

You can probably see what i am doing, (accessing different function based on sensor type), and Nothing has worked