[Boost-users] [Boost.Serialization] Derived class de-serialization problem due to MSVC linker

From: Markus.Himmerich_at_[hidden]
Date: 2008-07-10 03:53:24

Hi,

I am trying to serialize a large set of objects in our library. I am
using the 
Serialization library from version 1.33 with MSVC 2003. When I had all 
serialization code in the header files of the classes, linking took too
much 
time and memory. Therefore I am now using explicit template
instantiation 
of the serialize function (see below) in conjunction with precompiled
headers 
for the Boost.Serialization.

The problem is this: When I de-serialize a DerivedObject to a
BaseObject-pointer 
(so that only the header of the BaseObject class is included) the linker
seems 
to throw away the information from the explicit template instantiation
of the 
DerivedObject in some cases. When I combine the explicit template
instantiation 
and definition of serialize into one object for BaseObject and all
DerivedObject, 
the linker keeps the registration information of the derived class
(because MSVC 
uses object-level linking). Due to the coding standards in our
institution this 
method was disapproved.

Is there a way to make the linker keep the registration information of 
DerivedObject?

Best regards,
Markus Himmerich

.h-File:
----------------------------------------
namespace boost{
  namespace serialization {
    class access;
  }
}

class BaseObject {
public:
  ...
private:
  friend class boost::serialization::access;
  template<class Archive>
  void serialize(Archive & ar, const unsigned int /*version*/);
}

.cpp-File:
----------------------------------
#include <boost/archive/xml_iarchive.hpp>
#include <boost/archive/xml_oarchive.hpp>
#include <boost/serialization/export.hpp>
#include <boost/serialization/utility.hpp>
#include <boost/serialization/shared_ptr.hpp>
#include <boost/serialization/vector.hpp>
#include <boost/serialization/map.hpp>
#include <boost/serialization/set.hpp>
#include <boost/serialization/string.hpp>    //Use precompiled headers
for these headers

template<class Archive>
void BaseObject::serialize(Archive & ar, const unsigned int /*version*/)
{
  ar & BOOST_SERIALIZATION_NVP(id_);
  ar & BOOST_SERIALIZATION_NVP(data1_);
}
template void a::serialize<>(boost::archive::xml_iarchive & ar, const
unsigned int /*version*/);
template void a::serialize<>(boost::archive::xml_oarchive & ar, const
unsigned int /*version*/);
BOOST_CLASS_EXPORT(a)
BOOST_SERIALIZATION_SHARED_PTR(a)

Analogous files for DerivedObject.

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