Wrapping/PythonCore: use slots for number access

Wrapping/PythonCore/PyVTKReference.cxx

@@ -92,12 +92,18 @@ static PyObject* PyVTKReference_CompatibleObject(PyObject* self, PyObject* opn)
     }
 
     // check if it has number protocol and suitable methods
+#if PY_VERSION_HEX < 0x030A0000
     PyNumberMethods* nb = Py_TYPE(opn)->tp_as_number;
     if (nb)
+#endif
     {
-      if (nb->nb_index)
+#if PY_VERSION_HEX >= 0x030A0000
+      if (unaryfunc nb_index = (unaryfunc)PyType_GetSlot(Py_TYPE(opn), Py_nb_index))
+#else
+      if (unaryfunc nb_index = nb->nb_index)
+#endif
       {
-        opn = nb->nb_index(opn);
+        opn = nb_index(opn);
         if (opn == nullptr || !PyLong_Check(opn))
         {
           PyErr_SetString(PyExc_TypeError, "nb_index should return integer object");
@@ -105,9 +111,13 @@ static PyObject* PyVTKReference_CompatibleObject(PyObject* self, PyObject* opn)
         }
         return opn;
       }
-      else if (nb->nb_float)
+#if PY_VERSION_HEX >= 0x030A0000
+      else if (unaryfunc nb_float = (unaryfunc)PyType_GetSlot(Py_TYPE(opn), Py_nb_float))
+#else
+      else if (unaryfunc nb_float = nb->nb_float)
+#endif
       {
-        opn = nb->nb_float(opn);
+        opn = nb_float(opn);
         if (opn == nullptr || !PyFloat_Check(opn))
         {
           PyErr_SetString(PyExc_TypeError, "nb_float should return float object");

Wrapping/PythonCore/vtkPythonOverload.cxx

@@ -249,6 +249,11 @@ static int vtkPythonIntPenalty(PY_LONG_LONG tmpi, int penalty, char format)
 
 static bool vtkPythonCanConvertToInt(PyObject* arg)
 {
+#if PY_VERSION_HEX >= 0x030A0000
+  unaryfunc asint = (unaryfunc)PyType_GetSlot(Py_TYPE(arg), Py_nb_int);
+  unaryfunc asindex = (unaryfunc)PyType_GetSlot(Py_TYPE(arg), Py_nb_index);
+  return (asint || asindex);
+#else
   // Python 3.8 deprecated implicit conversions via __int__, so we must
   // check for the existence of the __int__ and __index__ slots ourselves
   // instead of simply attempting a conversion.
@@ -258,6 +263,7 @@ static bool vtkPythonCanConvertToInt(PyObject* arg)
 #else
   return (nb && nb->nb_int);
 #endif
+#endif
 }
 
 //------------------------------------------------------------------------------