-Woverloaded-virtual flag

[Schumacher, Gordon]

So... I'm getting warnings generated from the following code:

class A
{
   virtual A* foo()
              {var++; return this;}
   virtual A* foo(int16 idx)
              {return NULL;}
};

class B: public A
{
   virtual A* foo(int16 idx)
              {return new B(base + idx);}
}

Warning:  `virtual A* A::foo()' hidden
Warning:  by `virtual A* B::foo(short int)'


If my understanding is correct, this should not be a warning at all - both
forms of this function are defined in the parent class, so the base function
should not be hidden!
Am I confused on this?  I've also tried it without the "virtual" on class
B's function declaration.

Thanks!