> Drawbacks: Require a specific type can introduce compiler warnings if the caller doesn't pass the proper type (PyObject* or PyVarObject*). _Py_NewReference() and _Py_ForgetReference() seem to be properly used, but not PyObject_INIT() and PyObject_INIT_VAR().

I worked around this issue by adding a macro to cast the argument and declare the static inline function with a different name. Example:

static inline void _Py_INCREF(PyObject *op)
{
    _Py_INC_REFTOTAL;
    op->ob_refcnt++;
}

#define Py_INCREF(op) _Py_INCREF(_PyObject_CAST(op))