Re: [boost] Traits-based design and ODR

From: al (al_at_[hidden])
Date: 2002-04-30 13:08:12

At 12:05 PM 4/30/2002 -0500, boost-request_at_[hidden] wrote:
>I skimmed MC++D quickly, but couldn't find your rationale for choice of
>defaults.  I'm assuming it was something like "the safest, most commonly
>needed for a wide range of general uses."
>
>Instead, defaults would have to be chosen as "the most widely useful for
>interfacing between libraries."
>
>Now it may be that these two criteria result in the same set of
>defaults.  But you need to review your choice of defaults to make sure that
>is the case.
>
>-- Beman

IMO, providing defaults for a policy based classes like smart ptr is not
such a wise move. Template typedefs would be better. Since they are non
standard, a struct indirection should be used instead. But the man
(Andrei) is here, so I shan't say too much.

I generally agree with Andrei on policies over traits. Traits rely on
specialization and if the header containing the specialization is not
included, it compiles without an error, whereas policies would stop the
compiler flat.