Boost C++ Libraries: Ticket #4676: Ambiguous register_type with polymorphic_x_?archive on g++

attachment set

boost@… — Wed, 22 Sep 2010 18:36:38 GMT

attachment → register_type_ambig.cpp

g++ register_type ambiguity

attachment set

boost@… — Wed, 22 Sep 2010 18:37:05 GMT

attachment → register_type.patch

g++ register_type ambiguity patch

Richard Hazlewood — Wed, 22 Sep 2010 18:38:17 GMT

Note: this was with g++ 4.4

Robert Ramey — Sat, 25 Sep 2010 16:57:46 GMT

no way can I put a "using" declaration in a *.hpp file.

What we can do is add the following to polymorphic_oarchive:

    // register type function
    const basic_pointer_iserializer *
    register_type(T * t = NULL){
        return ArchiveImplementation::register_type(t);
    }

and similar block to polymorphic_oarchive. Would that not solve the issue. I've included this in my code base for eventual migration to trunk and release but don't have a specific test yet. Care to try this?

Robert Ramey

Sun, 26 Sep 2010 21:39:47 GMT

The "using" is a convenience (std: 7.3.3) to bring one of the routes to register_type<> into scope of the polymorphic_?archive_route classes. However, if you are concerned that a compiler may not support it, a routing register_type<>, as you specify, achieves the same ends - it matters not to me.

However, I suspect it will have to go at the same place as the using patch; i.e. in the archive::detail::polymorphic_?archive_route classes. It is at this point in the hierarchy that the two ambiguous routes to register_type<> (interface_?archive) occur; taking polymorphic_binary_oarchive as an example:

polymorphic_binary_oarchive:
      polymorphic_oarchive_route<>
                   |
   ----------------------------------------
   |                                      |
polymorphic_oarchive           (ArchiveImplementation)
   |                           binary_oarchive_impl<naked_binary_oarchive>
interface_oarchive<poly_oa>               |
                               basic_binary_oarchive<naked_binary_oarchive>
                                          |
                               common_oarchive<naked_binary_oarchive>
                                          |
                               -----------------------------
                               |                           |
                         basic_oarchive   interface_oarchive<naked_binary_oarchive>

I'm happy to test anything you have; is it on a branch in the SVN repository?

Robert Ramey — Wed, 20 Oct 2010 16:08:31 GMT

I have fixed this, test it, and checked it into the trunk.

Robert Ramey

status changed; resolution set

Robert Ramey — Wed, 20 Oct 2010 16:11:39 GMT

status new → closed
resolution → fixed