Re: [boost] [config] Variadic template macros in gcc header

Subject: Re: [boost] [config] Variadic template macros in gcc header
From: John Maddock (boost.regex_at_[hidden])
Date: 2010-11-21 04:40:19

> Why is there two mutually exclusive macros indicating variadic template 
> support for gcc ?
>
> There is the established BOOST_NO_VARIADIC_TEMPLATES which says that any 
> compiler does not have variadic template support. Then I find that for gcc 
> there is also BOOST_HAS_VARIADIC_TMPL which evidently says that the 
> compiler does have variadic template support, and is in no other compiler 
> header file than the gcc one. Since the two config macros are mutually 
> exclusive in the gcc header file, why is there any need for 
> BOOST_HAS_VARIADIC_TMPL ?

Historical baggage - the BOOST_HAS_ one is deprecated and no longer 
documented, new code should always be using the BOOST_NO_ version, the other 
is present for backwards compatibility.  BTW I've just committed a fix to 
Trunk to make sure that the two versions are normalized with respect to each 
other.  If someone wants to take on the task of getting the release branch 
free of the BOOST_HAS_ version, then they can also remove it from 
Boost.Config ;-)

HTH, John.