 etc.
};</pre>

    <hr>
    <h2><a name="xref">How can I find the existing PyObject that holds a C++
    object?</a></h2>

    <blockquote>
      "I am wrapping a function that always returns a pointer to an
      already-held C++ object."
    </blockquote>
    One way to do that is to hijack the mechanisms used for wrapping a class
    with virtual functions. If you make a wrapper class with an initial
    PyObject* constructor argument and store that PyObject* as "self", you
    can get back to it by cas