Re: [boost] MPL breaks type_traits with Borland C++ Builder 6

From: John Maddock (jm_at_[hidden])
Date: 2002-09-18 06:18:11

> > The new MPL code is now breaking all of the type traits test programs
> with
> > C++ Builder 6.
> >
> > First off there was a minor problem in integral_c.hpp caused by the
> recent
> > IBM C++ fixes (now fixed).
>
> Yeah, but you broke the old EDG compilers with that fix. Fun, eh? ;-)

Delightful :-)

> OK, I've checked in a possible fix for that one. Please look at it.
>
> > However there is a more serious problem in if.hpp caused by the line:
> >
> > BOOST_MPL_AUX_VOID_SPEC(3, if_)
>
> <snip>
>
> > The problem here is the nested template inside the if_ class, Builder 6
> > doesn't cope with default template parameters applied to template
classes
> > that are themselves template class members.  The fix is to remove the
> > default parameters and make sure that the apply template always gets
> passed
> > a full complement of parameters (it's only an implementation detail
> right?),
> > unfortunately you seem to be using this idiom quite a lot :-(
> >
> > Hoping you can fix this...
>
> I just checked in a patch based on the precise wording you supply there.
It
> passes Borland 5.5.1 at least.
> Please let me know if it works.

Yep, it all seems to working OK now, thanks for working on that.

John Maddock
http://ourworld.compuserve.com/homepages/john_maddock/index.htm