Re: [Boost-users] Serialization v1.33.0 and Serializing derived classes through base class

From: Daryle Walker (darylew_at_[hidden])
Date: 2005-12-04 14:08:42

On 12/3/05 10:56 PM, "David Parks" <davidp_at_[hidden]> wrote:

> I'm having a newbie issue with serialization on a derived class with a
> virtual function.  I'm using the 1.33.0 build on VS 7.1.
> I've shrunken my code to a micro-version of what I tried to do.  Here I
> have two classes, A and B, where B is a subclass of A.  They share a
> virtual function (ie B overrides dumpFunc in A).  I've registered B with
> BOOST_CLASS_EXPORT(B).  I've turned on RTTI in VS 7.1 (/GR or
> whatever).  Still, I get a run time assert error in the boost library
> telling me that the derived/base relationship wasn't registered.  Here's
> the code.  I'll try to spell out the error below.

Why don't you follow the error's advice and register the derived/base
relationship?  The registration is not automatic.

> #include <string>
> #include <fstream>
> 
> #include <boost/archive/tmpdir.hpp>
> 
> #include <boost/archive/text_iarchive.hpp>
> #include <boost/archive/text_oarchive.hpp>
> #include <boost/serialization/export.hpp>
> #include <boost/serialization/base_object.hpp>

You already included the necessary header, but you don't exploit it.

> #include <boost/serialization/utility.hpp>
> #include <boost/serialization/vector.hpp>
> 
> class A;
> class B;
> 
> class A
> {
>  friend class boost::serialization::access;
> 
>  template<class Archive>
>      void serialize(Archive & ar, const unsigned int version)
>  {
>      ar & m_className;
>  };
>  std::string m_className;
> public:
>  A()
>  {
>      m_className = "ClassA\n";
>  };
>  virtual void dumpFunc() {};
> };
> 
> 
> class B : public A
> {
>  friend class boost::serialization::access;
> 
>  template<class Archive>
>      void serialize(Archive & ar, const unsigned int version)
>  {

       // Add this line to acknowledge base classes
       ar & boost::serialization::base_object<A>(*this);

>      ar & m_classNameB;
>  };
>  std::string m_classNameB;
> public:
>  B()
>  {
>      m_classNameB = "ClassB\n";
>  };
>  virtual void dumpFunc() {};
> };
> 
> BOOST_CLASS_EXPORT(B)
> 
> void main()
> {
>  std::vector<A *> vecA;
>  B *b=new B();
>  vecA.push_back(b);
> 
>  std::ofstream ofs("saveFile.sav");
>  boost::archive::text_oarchive oa(ofs);
>  oa & vecA;
> 
>  delete b;
> }
[TRUNCATE stack trace]

-- 
Daryle Walker
Mac, Internet, and Video Game Junkie
darylew AT hotmail DOT com