I'd like to write a class in C++, then use a tool like SWIG (or Boost.Python, if absolutely necessary) to make a shared library/Python module. Then, I want to write python code that uses the boost.mpi python module to pass messages containing instances of my C++ class. In other words, I want to do what's described here: "Boost.MPI also supports efficient serialization and transmission of C++ objects (that have been exposed to Python) through its C++ interface. Any C++ type that provides (de-)serialization routines that meet the requirements of the Boost.Serialization library is eligible for this optimization, but the type must be registered in advance. To register a C++ type, invoke the C++ function register_serialized. If your C++ types come from other Python modules (they probably will!), those modules will need to link against the boost_mpi and boost_mpi_python libraries as described in the installation section. Note that you do not need to link against the Boost.MPI Python extension module." ( from http://www.boost.org/doc/libs/1_35_0/doc/html/mpi/python.html#mpi.python_use... ) I've looked at the documentation for the function register_serialized, but I am evidentally using it incorrectly, because I get compile time errors. My class looks like this: #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/mpi/python/serialize.hpp> class Testclass { private: static bool registered; int data; friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & data; } public: Testclass() { if(!registered) { registered = true; boost::mpi::python::register_serialized(*this); } } void set_data(const int & in) { data = in; } int get_data() { return data; } }; bool Testclass::registered = false; I might be so far out in left field that what I'm trying to accomplish here needs explanation. According to the only documentation I can find, register_serialized is defined this way: template<typename T> void register_serialized(const T & value = T(), PyTypeObject * type = 0); The parameters have this meaning: type: "The Python type associated with the C++ type T. If not provided, it will be computed from the same value value." value: "A sample value of the type T. This may be used to compute the Python type associated with the C++ type T" So, I'm trying to register my class by passing in the object pointed to by this. I figure I only need to register it once; hence the static member. When I try to compile this to an object file, I get this error: /share/home/00791/adam/boost/include/boost-1_35/boost/mpi/python/serialize.hpp(323): error: no operator "<<" matches these operands operand types are: boost::mpi::packed_oarchive << Testclass ar << value; ^ detected during: instantiation of "void boost::python::detail::direct_serialization_table<IArchiver, OArchiver>::default_saver<T>::operator()(OArchiver &, const boost::python::api::object &, unsigned int) [with IArchiver=boost::mpi::packed_iarchive, OArchiver=boost::mpi::packed_oarchive, T=Testclass]" at line 158 of "/share/home/00791/adam/boost/include/boost-1_35/boost/function/function_template.hpp" Followed by several lines of similar messages, which I can attach if anyone needs to see them. There's one final wrinkle.. I've been trying to build boost for the past few days, and I kept getting a very simliar compile error at the same point. One of the authors of Boost.MPI took a look at it and submitted this change, which I made manually on my system: http://svn.boost.org/trac/boost/changeset/45825 Only after that change was I able to build Boost. Thanks