[boost] BOOST_PP_ITERATE for huge mpl and fusion

Subject: [boost] BOOST_PP_ITERATE for huge mpl and fusion
From: Hite, Christopher (Christopher.Hite_at_[hidden])
Date: 2012-03-07 07:08:01

"Not to 50!!!" - Princess Bride

Things like mpl::vector and fusion::map have a configured limit like BOOST_MPL_LIMIT_VECTOR_SIZE.

The documentation is dodgy and doesn't mention that while it is configurable you can't really configure it to be more than 50.   Many people have stumbled here:
http://boost.2283326.n4.nabble.com/msm-Boost-MPL-vector-limit-size-exceeded-td2600696.html
http://lists.boost.org/Archives/boost/2004/08/70900.php
http://comments.gmane.org/gmane.comp.lib.boost.user/55679
http://lists.boost.org/Archives/boost/2010/09/170443.php
Appearantly there are some scripts to generate these headers, but they may not work anymore.

I had to rush hack things in my code to make several containers go over 50 in one compilation scope.

#define ULTIMATE_N 70
#include <boost/mpl/vector/vector50.hpp>

namespace boost { namespace mpl {

#   define BOOST_PP_ITERATION_PARAMS_1 \
        (3,(51, ULTIMATE_N, <boost/mpl/vector/aux_/numbered.hpp>))
#   include BOOST_PP_ITERATE()

}}

I'd really like to fix this in boost.  AFAICT all I have to do is find all *50.hpp files and replace the 50 with the appropriate config limit.

I count 74 instances of this stuff going on!  Mostly it's phoenix, mpl, and fusion.

So to wrap it up my questions are:
1) Do the scripts still work?  Does anyone use them?  Are they regularly tested?
2) Does anyone see a problem with my simple fix?

Chris