Checking in the code for PEP 357.
This was mostly written by Travis Oliphant.
I've inspected it all; Neal Norwitz and MvL have also looked at it
(in an earlier incarnation).
diff --git a/Include/abstract.h b/Include/abstract.h
index 73dc91d..9ec18fa 100644
--- a/Include/abstract.h
+++ b/Include/abstract.h
@@ -748,6 +748,14 @@
 
        */
 
+     PyAPI_FUNC(Py_ssize_t) PyNumber_Index(PyObject *);
+
+       /*
+	 Returns the object converted to Py_ssize_t on success 
+	 or -1 with an error raised on failure.
+       */
+
+
      PyAPI_FUNC(PyObject *) PyNumber_Int(PyObject *o);
 
        /*