Passing Python list to C++ vector using Boost.python

How do I pass a Python list of my object type ClassName to a C++ function that accepts a vector<ClassName>?

The best I found is something like this: example. Unfortunately, the code crashes and I can't seem to figure out why. Here's what I used:

template<typename T>
void python_to_vector(boost::python::object o, vector<T>* v) {
    try {
      object iter_obj = object(handle<>(PyObject_GetIter(o.ptr())));
      return;
      for (;;) {
          object obj = extract<object>(iter_obj.attr("next")());
          // Should launch an exception if it cannot extract T
          v->emplace_back(extract<T>(obj));
      }
    } catch(error_already_set) {
        PyErr_Clear();
        // If there is an exception (no iterator, extract failed or end of the
        // list reached), clear it and exit the function
        return;
    }
}