Issue #1967: Backport dictionary views.
diff --git a/Include/dictobject.h b/Include/dictobject.h
index 06e0a7e..dfd42dc 100644
--- a/Include/dictobject.h
+++ b/Include/dictobject.h
@@ -89,10 +89,22 @@
 };
 
 PyAPI_DATA(PyTypeObject) PyDict_Type;
+PyAPI_DATA(PyTypeObject) PyDictIterKey_Type;
+PyAPI_DATA(PyTypeObject) PyDictIterValue_Type;
+PyAPI_DATA(PyTypeObject) PyDictIterItem_Type;
+PyAPI_DATA(PyTypeObject) PyDictKeys_Type;
+PyAPI_DATA(PyTypeObject) PyDictItems_Type;
+PyAPI_DATA(PyTypeObject) PyDictValues_Type;
 
 #define PyDict_Check(op) \
                  PyType_FastSubclass(Py_TYPE(op), Py_TPFLAGS_DICT_SUBCLASS)
 #define PyDict_CheckExact(op) (Py_TYPE(op) == &PyDict_Type)
+#define PyDictKeys_Check(op) (Py_TYPE(op) == &PyDictKeys_Type)
+#define PyDictItems_Check(op) (Py_TYPE(op) == &PyDictItems_Type)
+#define PyDictValues_Check(op) (Py_TYPE(op) == &PyDictValues_Type)
+/* This excludes Values, since they are not sets. */
+# define PyDictViewSet_Check(op) \
+	(PyDictKeys_Check(op) || PyDictItems_Check(op))
 
 PyAPI_FUNC(PyObject *) PyDict_New(void);
 PyAPI_FUNC(PyObject *) PyDict_GetItem(PyObject *mp, PyObject *key);