Re: [boost] Re: Mac OS 10 & type_traits/type_with_alignment.hpp

From: Douglas Paul Gregor (gregod_at_[hidden])
Date: 2003-11-05 18:11:15

On Wed, 5 Nov 2003, David Abrahams wrote:

> "Ralf W. Grosse-Kunstleve" <rwgk_at_[hidden]> writes:
>
> > Hi Doug,
> >
> > Mike Owen reports the same problem while compiling Boost.Python extensions
> > under AIX with g++ 3.2.1 and 3.2.3. type_with_alignment.hpp does not cope with
> > a type that is 8-byte aligned.
> >
> > We have established that the little test below runs under AIX without crashing.
> >>From that we conclude that AIX does not have strict alignment requirements,
> > just like the PowerPC Macintosh. Would it seem reasonable to check in the
> > trivial patch below?
>
> FWIW, whether alignment is strict isn't dependent on the OS but on CPU
> technology.  The alignments that can be generated are dependent not on
> the OS but on the compiler.  Checking the OS seems like the wrong
> thing to do.
>
> --
> Dave Abrahams
> Boost Consulting
> www.boost-consulting.com

The "right" answer is to use GCC's __attribute__ mechanism to get types of
the correct alignment. I've got a partial patch locally, that I'll try to
complete and test tonight.

        Doug