Proposed resolution (July, 2009):

Change 11.7.3 [class.virtual] paragraph 2 as follows:

...Then in any well-formed class, for each virtual function declared in that class or any of its direct or indirect base classes there is a unique final overrider that overrides that function and every other overrider of that function. The rules for member lookup (6.5.2 [class.member.lookup]) are used to determine the final overrider for a virtual function in the scope of a derived class but ignoring names introduced by using-declarations. A virtual member function C::vf of a class object S is a final overrider unless the most derived class (6.7.2 [intro.object]) of which S is a base class subobject (if any) declares or inherits another member function that overrides vf. In a derived class, if a virtual member function of a base class subobject has more than one final overrider, the program is ill-formed. [Example: ... —end example] [Example:

    struct A { virtual void f(); };
    struct B: A { };
    struct C: A { void f(); };
    struct D: B, C { };    // OK; A::f and C::f are the final overriders
                           // for the B and C subobjects, respectively

—end example]