RE: [boost] Recent PP changes/EDG

From: Aleksey Gurtovoy (agurtovoy_at_[hidden])
Date: 2002-06-19 06:21:44

Paul Mensonides wrote:
> 1) I modified <boost\mpl\aux_\preprocessor.hpp> so that the 
> arguments to
> BOOST_PP_ADD in both BOOST_MPL_AUX_TEMPLATE_PARAMETER and
> BOOST_MPL_AUX_DEFAULT_TEMPLATE_PARAMETER are reversed.  This 
> is significantly more efficient.

Thanks, Paul. "mpl_v2" follows this Vesa's recommendation as well, I just
didn't integrate the changes back into mpl-development.

> The only major bottleneck remaining is
> BOOST_MPL_AUX_LIST_FACTORY_SPECIALIZATION.  In this case, the 
> pure *amount* of text all on one line is crippling to EDG's preprocessor.
The 
> only way around this is to use file iteration, I can add that support 
> tomorrow if you are interested.

Actually, this file ("boost/mpl/list/factory.hpp") has always been a
bottleneck for EDG-based compilers, and the preprocessed version -
"boost/mpl/aux_/preprocessed/factory.hpp" - should take care of the
performance problems. If it doesn't, then for some reason (not for the first
time) the conditional include on top of original "factory.hpp" header
doesn't work.

Aleksey