 happens in response to some code like this:
<pre>
period const&amp; get_floating_frequency() const
{
  return boost::python::call_method&lt;period const&amp;&gt;(
      m_self,"get_floating_frequency");
}
</pre>
    And you get:
<pre>
ReferenceError: Attempt to return dangling reference to object of type:
class period
</pre>

    <p>In this case, the Python method invoked by <code>call_method</code>
    constructs a new Python object. You're trying to return a reference to a
    C++ object (an instance of 