[C++-sig] serialization

[Neal D. Becker]

Now serialization will hopefully be part of boost soon.  It would be good to
share a single serialization implementation, so that a class could be
serialized in c++ using boost or by python.

Here is one way to achieve this.  Assume

  template<class Archive>
  void serialize(Archive & ar, const unsigned int version);

is added to your class.  Then an easy way to use this from boost::python is
to serialize to a stringstream, and pickle the resulting string.  Here is
an example:

struct mt_pickle_suite : python::pickle_suite {
    
  static python::object getstate (rng_t& rng) {
    std::ostringstream os;
    boost::archive::binary_oarchive oa(os);
    oa << rng;
    return python::str (os.str());
  }

  static void
  setstate(rng_t& rng, python::object entries) {
    python::str s = python::extract<python::str> (entries)();
    std::string st = python::extract<std::string> (s)();
    std::istringstream is (st);
    
    boost::archive::binary_iarchive ia (is);
    ia >> rng;
  }
};