I'm afraid of you can't, according to the code, it's implemented in
builtin_converters.cpp:
slot_rvalue_from_python();
Boost/Python using global registration only according type saw in C++, I
don't known is it possible to overrides these.
how about return a wrap type of long double to cheating boost/python, and
register youself converter as
PyObject * o = PyArrayScalar_New(LongDouble);
PyLongDoubleScalarObject * s = (PyLongDoubleScalarObject*)o;
s->obval = value;
Don't forget to call import_array() in your model init functio
