[Boost-users] Re: Boost.Serialization 1.32 trouble reading back an object first serialized in an std::vector then by pointer

From: Robert Ramey (ramey_at_[hidden])
Date: 2005-06-08 11:38:38

I'll look at this.  Give me a couple of days.

Robert Ramey

James Conrad wrote:
> I'm evaluating the Boost.Serialization for use internal use as an
> interchange format between a number of loose knit projects, and I've
> run into a bit of trouble.
>
> I'm using Vc 7.1 in Visual Studio .NET 2003.
>
> It seems to me that, if I serialize an object first in an std::vector,
> and then serialize it later by pointer, that there is trouble reading
> it back.
>
> I boiled down the reproduction case to as little code as possible
> below.
>
> When newPolygon (below) is loaded from the archive, I get a bogus
> pointer for m_pLastVertex.  If I serialize using a binary archive, I
> hit an assert in basic_iarchive.cpp line 371:
>
>         assert(new_cid == cid);
>
> Where cid is 576 and new_cid is 2.
>
> Any help with this would be appriciated,
>
> Thanks in advance,
> -james conrad
>
>
> #include <fstream>
>
> #define BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
>
> #include <boost/archive/xml_oarchive.hpp>
> #include <boost/archive/xml_iarchive.hpp>
>
> #include <boost/serialization/vector.hpp>
> #include <boost/serialization/export.hpp>
>
> class Vector3
> {
> public:
>     Vector3() {}
>     Vector3( float x, float y, float z ) : _x(x), _y(y), _z(z) {}
>
>     friend class boost::serialization::access;
>     template<class Archive>
>     void serialize(Archive & ar, const unsigned int version)
>     {
>         ar & BOOST_SERIALIZATION_NVP(_x);
>         ar & BOOST_SERIALIZATION_NVP(_y);
>         ar & BOOST_SERIALIZATION_NVP(_z);
>     }
>
>     float _x,_y,_z;
> };
>
> BOOST_CLASS_EXPORT_GUID(Vector3, "Vector3")
>
> class Polygon
> {
> public:
>     Polygon() : m_pLastVertex( NULL ) {}
>
>     friend class boost::serialization::access;
>     template<class Archive>
>     void serialize(Archive & ar, const unsigned int version)
>     {
>         ar & BOOST_SERIALIZATION_NVP(m_vertices);
>         ar & BOOST_SERIALIZATION_NVP(m_pLastVertex);
>     }
>
>     void addVertex( const Vector3& vert )
>     {
>         m_vertices.push_back( vert );
>         m_pLastVertex = &m_vertices.back();
>     }
>
>     std::vector<Vector3>    m_vertices;
>     Vector3*                m_pLastVertex;
> };
>
> BOOST_CLASS_EXPORT_GUID(Polygon, "Polygon")
>
> int main( int argc, char* argv[] )
> {
>     // create class instance
>     Polygon poly;
>     poly.addVertex( Vector3( 0.0f, 1.0f, 0.0f ) );
>     poly.addVertex( Vector3( 1.0f, 0.12565f, 0.2f ) );
>     poly.addVertex( Vector3( 15.0f, 1.22f, 6.7f ) );
>     poly.addVertex( Vector3( 1.43f, 1.55f, 2.5f ) );
>
>     // create and open a character archive for output
>     std::ofstream ofsx( "testout.xml" );
>     boost::archive::xml_oarchive oax( ofsx );
>
>     // write class instance to archive
>     oax << BOOST_SERIALIZATION_NVP(poly);
>
>     // close archive
>     ofsx.close();
>
>     Polygon newPoly;
>
>     // create and open an archive for input
>     std::ifstream ifs("testout.xml", std::ios::binary);
>     boost::archive::xml_iarchive ia(ifs);
>     // read class state from archive
>     ia >> BOOST_SERIALIZATION_NVP( newPoly );
>     // close archive
>     ifs.close();
>
>     return 0;
> }
>
>
> Here is an example of the .xml output:
>
> <?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
> <!DOCTYPE boost_serialization>
> <boost_serialization signature="serialization::archive" version="3">
> <poly class_id="0" tracking_level="1" version="0" object_id="_0">
>     <m_vertices class_id="1" tracking_level="0" version="0">
>         <count>4</count>
>         <item class_id="2" tracking_level="1" version="0"
>             object_id="_1"> <_x>0</_x>
>             <_y>1</_y>
>             <_z>0</_z>
>         </item>
>         <item object_id="_2">
>             <_x>1</_x>
>             <_y>0.12565</_y>
>             <_z>0.2</_z>
>         </item>
>         <item object_id="_3">
>             <_x>15</_x>
>             <_y>1.22</_y>
>             <_z>6.6999998</_z>
>         </item>
>         <item object_id="_4">
>             <_x>1.4299999</_x>
>             <_y>1.55</_y>
>             <_z>2.5</_z>
>         </item>
>     </m_vertices>
>     <m_pLastVertex class_id_reference="2"
> object_id_reference="_4"></m_pLastVertex>
> </poly>