ython
    registry near the top of the module initialization function. Once
    flow control has passed through the registration code the automatic
    conversions from and to Python strings will work in any module
    imported in the same process.

<pre>#include &lt;boost/python/module.hpp&gt;
#include &lt;boost/python/def.hpp&gt;
#include &lt;boost/python/to_python_converter.hpp&gt;

namespace sandbox { namespace {

  class custom_string
  {
    public:
      custom_string() {}
      custom_string(std::st