[boost] Re: is_base_and_derived question

From: Gennaro Prota (gennaro_prota_at_[hidden])
Date: 2003-01-30 07:55:52

On Thu, 30 Jan 2003 12:38:36 -0000, "John Maddock"
<jm_at_[hidden]> wrote:

>Except it *doesn't work* !
>
>The problem is that your static assertion don't test anything, changing to:
>
>//typedef char TestA[is_base_and_derived<B, D>::result]; // Multiple bases
>(error on g++)
>typedef char TestB[is_base_and_derived<B1,D>::result ? 1 : -1];
>//typedef char TestC[is_base_and_derived<B2,D>::result]; // Private base
>(error on g++)
>typedef char TestD[!is_base_and_derived<int,D>::result ? 1 : -1];
>typedef char TestE[!is_base_and_derived<B, B>::result ? 1 : -1];
>typedef char TestF[is_base_and_derived<B,DV>::result ? 1 : -1]; // Virtual
>base
>
>and both Borland and gcc 3.21 give errors on cases 2 and 6

John, unfortunately I have to turn off my computer now. I had just
hacked up a version that seems to work with gcc, but I don't want to
post it before a better testing. I'll let you know in the morning.

Genny.