Re: C++ question: MI vs. pure virtuals

[Chip Salzenberg <chip at valinux dot com>]

According to llewelly@198.dsl.xmission.com:
> On Fri, 31 Dec 1999, Chip Salzenberg wrote:
> > 	class A { virtual void f() = 0; };  // PURE VIRTUAL
> > 	class B { void f() {} };            // NON-VIRTUAL
> >     class C {};                         // ??
> > 
> > Is class C abstract like A, or not?
> 
> So I am going to assume you meant to ask about this:
> 
>   struct A {virtual void f()=0;};
>   struct B {void f() {}};
>   struct C :public A,public B {};

D'oh!  Yes.  Consider that my mistake for this millenium (GMT).  :-)

> Since A is not a base class of B, B::f() does not overide (does not
>   implement) A::f(). (See sections 10.2, p2 (for name lookup), 10.3 p2,
>   (for overriding of virtual functions) 10.4 (abstract base classes), and 
>   pay particular attention to all of the examples in these sections.)

Thank you for the precise answer.  I shall examine those sections.

In a related question, a slight variation that I tried with gcc 2.96 is:

   struct A {virtual void f()=0;};
   struct B {void f() {}};
   struct C : public A, public B { using B::f; };

That didn't work either (the compiler still considered C abstract).
To your understanding, is the compiler still correct in this case?
(I expect that it is, but it doesn't hurt to ask.)
-- 
Chip Salzenberg             - a.k.a. -              <chip@valinux.com>
     "Fleagal.  Bingo.  Drooper.  Snork.  They're cops."   //MST3K