On Oct 29, 2007, at 11:08 AM, Eric Niebler wrote:
Douglas Gregor wrote:
On Sat, 2007-10-27 at 11:08 -0400, Arkadiy Vertleyb wrote:
"Eric Niebler" <eric@boost-consulting.com> wrote
In order for BOOST_TYPEOF to work with xpressive's static regexes (something I'm actively trying to support), I need registrations for reference_wrapper<> and mpl::int_<>. I'm happy to add them, but I'm not sure where. Thoughts? <snip>
There are several libraries that have this kind of problem. typeof needs registrations, serialization needs serialize() functions, MPI needs datatype traits, etc. I wonder if we can solve this problem for all of Boost with some kind of automatic scheme that says: if you include header A from one library and header B from another library, you automatically get whatever glue makes A and B work well together. [snip]
I don't think this is a very good idea. Take a really basic example like boost/ref.hpp, that is included *everywhere*. Are you really going to add PP blocks like this to ref.hpp for every library in boost that includes it? That would be almost every library in Boost, and it would be an continuing maintenance problem for the author of ref.hpp.
Well, for every library that has traits that need to be specialized for many of Boost's types.
I think the better solution is the one Arkadiy suggested ... that there is a dedicated place for such registrations so interested parties can add them if they need them. I'd be happy with his suggestion of $BOOST_ROOT/boost/typeof_registrations/<library>/.
Right, but we'll then need $BOOST_ROOT/boost/serialization/ <library>/, and $BOOST_ROOT/boost/mpi/<library>/, and so on. Doug