[boost] Re: is_base_and_derived question

From: Eric Niebler (neric_at_[hidden])
Date: 2003-02-01 23:01:15

"Gennaro Prota" <gennaro_prota_at_[hidden]> wrote
>
> Well, then I imagine you would prefer the old semantics. Was there
> anybody complaining that being not enough?
>

Yes, I was.  A while back, I pointed out to Rani that is_base_and_derived
was insufficient to implement is_com_ptr, a trait I needed.  In COM
programming, every interface inherits from IUnknown, and many COM objects
implement multiple interfaces.  So is_base_and_derived<IUnknown,
MyCOMObject> was almost always ambiguous.

I was content to gripe, but Rani actually did something about it.  The new
behavior of is_base_and_derived is very welcome, IMO.

Eric