I am not sure in this is a good idea to put into the language as you still
have to define lock for class A. I think this would be better to define in
the core guidelines as to avoid this issue. Also if A::lock is not mark a
virtual both B::lock and C::lock are available by typecasting A as a type
of B or C.

On Tue, Mar 17, 2020 at 1:12 PM Ryan Nicholl via Std-Proposals <
std-proposals_at_[hidden]> wrote:

>
> Consider:
>
> class A : public B, public C
> {
> virtual int lock();
> };
>
> what happens if both B::lock and C::lock exist as virtual functions? we
> can override them both with one function... but what if they are interfaces
> that do different things and happen to use the same name?
>
> Suggestion, specific override specifier:
>
> virtual int lock_mutex() override(int B::lock());
> virtual int lock_device() override(int C::lock());
>
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>