Hello,
I've been trying out boost::serialization and ran into a problem
trying to serialize objects of derived classes.
I set up this simple class hierarchy:
class BaseNode {
std::vector children_;
...
friend class boost::serialization::access;
template<class Archive>
void serialize(Archive &ar, unsigned version) {
ar & children_;
}
};
class DerivedNode : public BaseNode
{
...
friend class boost::serialization::access;
template<class Archive>
void serialize(Archive &ar, unsigned version) {
ar & boost::serialization::base_object<BaseNode>(*this);
}
};
All works fine as long as I register the types with the archives:
arch.register_type(static_cast(NULL));
arch.register_type(static_cast(NULL));
Now the documentation suggests exporting the classes as an alternative
to that. But when I instead put
BOOST_CLASS_EXPORT(BaseNode)
BOOST_CLASS_EXPORT(DerivedNode)
the polymorphism is not handled correctly and e.g. a tree of 3
DerivedNodes is restored as a single BaseNode object.
What am I missing here?
The full code for this test is at
http://noonti.de/tree_serialization.cpp.txt
Thanks,
Jens
