
};

struct B
{
  A a;
  B(const A& a_):a(a_){}
};

// Converter from A to python int
struct BToPython 
#if defined BOOST_PYTHON_SUPPORTS_PY_SIGNATURES //unnecessary overhead if py signatures are not supported
   : converter::to_python_target_type&lt;A&gt;  //inherits get_pytype
#endif
{
  static PyObject* convert(const B& b)
  {
    return incref(object(b.a).ptr());
  }
};

// Conversion from python int to A
struct BFromPython
{
  BFromPython()
  {
    boost::python::converter::registry::push_back
        