Re: [boost] Re: A couple of issues in submitting typelists to boost

From: Vesa Karvonen (vesa.karvonen_at_[hidden])
Date: 2001-11-26 07:40:55

From: "Daniel Frey" <daniel.frey_at_[hidden]>
> I like Vesa's approach:
>
>    is< D >::derived_from< B >::value
>    is< B >::base_of< D >::value
>
> Is it possible to make this work on most compilers?

My comment was really meant as a joke... I should have added a smiley. (How
many of you did laugh?)

Yes. It is possible to make it work (except on some broken compilers), but you
would often need to write:

    is< D >::template derived_from< B >::value

which is not ideal. I also don't like the idea of lumping several
metafunctions together.

As I explained in a private e-mail to Andrei Alexandrescu over six months ago,
I would personally prefer:

    is_base_derived<B,D>::value