Re: [boost] boost/type_traits/detail/bool_trait_def.hpp

From: Aleksey Gurtovoy (agurtovoy_at_[hidden])
Date: 2003-11-20 13:07:24

David Abrahams wrote:
> It seems to me that which type traits headers choose to #include the
> corresponding bool_trait_undef.hpp is inconsistent.

AFAICS, type_traits headers are fine. Except for one minor degradation due
to maintenance in "is_polymorphic.hpp", all other headers consistently
follow "the last #include" policy which guarantees the absence of issues you
are experiencing.

> I just changed
> some #includes and suddenly started seeing very mysterious errors
> because the corresponding macros were undefined.

Are you sure that doesn't happen because of inconsistency of
"bool_trait_undef.hpp" includes in your own headers?

> Should we add some checks to make sure neither header is #included
> twice in a row without the other header intervening?

IMO as long as everybody preserves the documented bool_trait_undef usage, we
are safe as is. If somebody doesn't, she will notice.

Aleksey