Re: [Boost-users] [serialization] DLL woes

From: Markus Bernhardt (Markus.Bernhardt_at_[hidden])
Date: 2007-07-06 00:21:35

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Hi Anders,

I had exactly the same problem three days ago. I have found no way to
prevent the compiler from instantiating some templates with
serialization code in multiple DLLs. My solution was to switch from
intrusive to non intrusive serialization and putting all serialization
binaries in a third DLL.

How it works (for me):

1. Rename all
    template <class Archive>
    void serialize(Archive& ar, const unsigned int version) { ... }
to
    template <class Archive>
    void my_serialize(Archive& ar, const unsigned int version) { ... }
and make it public.

2. Remove all serialization headers and macros from the existing code.

3. Create a new DLL.

4. For every serializable class I have there a .cpp file which looks like:

#include <boost/archive/binary_oarchive.hpp>
#include <boost/archive/binary_iarchive.hpp>
#include <boost/serialization/base_object.hpp>
#include <boost/serialization/export.hpp>
#include "abstracts.h"

namespace boost
{
  namespace serialization
  {
    template <class Archive> void serialize(Archive& ar, MyClass& obj,
const unsigned int version) {
      obj.template bm_serialize<Archive>(ar, version);
    }
  }
}

BOOST_CLASS_EXPORT(MyClass);
BOOST_SHARED_POINTER_EXPORT(MyClass);

5. One additional file abstracts.h which looks like:

#ifndef BM_SERIALITATION_ABSTRACTS_H_
#define BM_SERIALITATION_ABSTRACTS_H_

BOOST_IS_ABSTRACT(MyBaseClass)

#endif

#########################

I'm not sure this is the preferred way to handle things, but at least it
works for me.

Best regards,
Markus

Anders Wang Kristensen schrieb:
> Hi,
> 
> I'm trying to serialize a class using two functions located in different 
> DLLs.
> 
> I can serialize fine by calling one function, but when I call the second it 
> triggers
> an assertion in extended_type_info.cpp:
> 
>         // make sure that attempt at registration is done only once
>         assert(lookup(eti) == m_self->m_map.end());
> 
> Apparently the class is registered twice, but how do I avoid that?
> 
> -- Anders 
> 
> 
> _______________________________________________
> Boost-users mailing list
> Boost-users_at_[hidden]
> http://lists.boost.org/mailman/listinfo.cgi/boost-users

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