Make bin() implementation parallel oct() and hex() so that int/long subclasses can override or so that other classes can support.
diff --git a/Include/object.h b/Include/object.h
index 59f3b9e..709174f 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -267,6 +267,9 @@
 
 	/* Added in release 2.5 */
 	unaryfunc nb_index;
+
+	/* Added in release 2.6 */
+	unaryfunc nb_bin;
 } PyNumberMethods;
 
 typedef struct {
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index f1fb615..c98117a 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -523,7 +523,7 @@
         len_typeobject = p + 2*l + 15*p + l + 4*p + l + 9*p +\
                          l + 11*p + self.align(4)
         self.check_sizeof(class_newstyle,
-                          h + len_typeobject + 41*p + 10*p + 3*p + 6*p)
+                          h + len_typeobject + 42*p + 10*p + 3*p + 6*p)
 
     def test_specialtypes(self):
         i = self.i
diff --git a/Misc/NEWS b/Misc/NEWS
index 9bd4f3c..9e02d76 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -4,6 +4,15 @@
 
 (editors: check NEWS.help for information about editing NEWS using ReST.)
 
+What's New in Python 2.6 beta 2?
+================================
+
+Core and Builtins
+-----------------
+
+- Make bin() implementation parallel oct() and hex().
+
+
 What's New in Python 2.6 beta 1?
 ================================
 
diff --git a/Objects/intobject.c b/Objects/intobject.c
index f98aee0..5210ee8 100644
--- a/Objects/intobject.c
+++ b/Objects/intobject.c
@@ -934,6 +934,12 @@
 }
 
 static PyObject *
+int_bin(PyObject *v)
+{
+        return PyNumber_ToBase(v, 2);
+}
+
+static PyObject *
 int_oct(PyIntObject *v)
 {
 	return _PyInt_Format(v, 8, 0);
@@ -1231,6 +1237,7 @@
 	0,			/* nb_inplace_floor_divide */
 	0,			/* nb_inplace_true_divide */
 	(unaryfunc)int_int,	/* nb_index */
+	(unaryfunc)int_bin, 	/* nb_bin */
 };
 
 PyTypeObject PyInt_Type = {
diff --git a/Objects/longobject.c b/Objects/longobject.c
index c65d0c0..b603dda 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -3301,6 +3301,12 @@
 }
 
 static PyObject *
+long_bin(PyObject *v)
+{
+        return PyNumber_ToBase(v, 2);
+}
+
+static PyObject *
 long_oct(PyObject *v)
 {
 	return _PyLong_Format(v, 8, 1, 0);
@@ -3540,6 +3546,7 @@
 	0,				/* nb_inplace_floor_divide */
 	0,				/* nb_inplace_true_divide */
 	long_long,			/* nb_index */
+	long_bin,			/* nb_bin */
 };
 
 PyTypeObject PyLong_Type = {
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index e0ae55b..093fd20 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -3743,6 +3743,7 @@
 		if (base->tp_flags & Py_TPFLAGS_HAVE_INDEX) {
 			COPYNUM(nb_index);
 		}
+		COPYNUM(nb_hex);
 	}
 
 	if (type->tp_as_sequence != NULL && base->tp_as_sequence != NULL) {
@@ -5135,6 +5136,7 @@
 SLOT0(slot_nb_int, "__int__")
 SLOT0(slot_nb_long, "__long__")
 SLOT0(slot_nb_float, "__float__")
+SLOT0(slot_nb_bin, "__bin__")
 SLOT0(slot_nb_oct, "__oct__")
 SLOT0(slot_nb_hex, "__hex__")
 SLOT1(slot_nb_inplace_add, "__iadd__", PyObject *, "O")
@@ -5802,6 +5804,8 @@
 	       "long(x)"),
 	UNSLOT("__float__", nb_float, slot_nb_float, wrap_unaryfunc,
 	       "float(x)"),
+	UNSLOT("__bin__", nb_bin, slot_nb_bin, wrap_unaryfunc,
+	       "bin(x)"),
 	UNSLOT("__oct__", nb_oct, slot_nb_oct, wrap_unaryfunc,
 	       "oct(x)"),
 	UNSLOT("__hex__", nb_hex, slot_nb_hex, wrap_unaryfunc,
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index e18eb2a..7647523 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -211,7 +211,24 @@
 static PyObject *
 builtin_bin(PyObject *self, PyObject *v)
 {
-        return PyNumber_ToBase(v, 2);
+	PyNumberMethods *nb;
+	PyObject *res;
+
+	if ((nb = v->ob_type->tp_as_number) == NULL ||
+	    nb->nb_hex == NULL) {
+		PyErr_SetString(PyExc_TypeError,
+			   "bin() argument can't be converted to hex");
+		return NULL;
+	}
+	res = (*nb->nb_bin)(v);
+	if (res && !PyString_Check(res)) {
+		PyErr_Format(PyExc_TypeError,
+			     "__bin__ returned non-string (type %.200s)",
+			     res->ob_type->tp_name);
+		Py_DECREF(res);
+		return NULL;
+	}
+	return res;
 }
 
 PyDoc_STRVAR(bin_doc,