Issue #4129: Belatedly document which C API functions had their argument(s) or
return type changed from int or int * to Py_ssize_t or Py_ssize_t * as this
might cause problems on 64-bit platforms.
diff --git a/Doc/c-api/set.rst b/Doc/c-api/set.rst
index a60ccd6..4bac96b 100644
--- a/Doc/c-api/set.rst
+++ b/Doc/c-api/set.rst
@@ -116,6 +116,10 @@
``len(anyset)``. Raises a :exc:`PyExc_SystemError` if *anyset* is not a
:class:`set`, :class:`frozenset`, or an instance of a subtype.
+ .. versionchanged:: 2.5
+ This function returned an :ctype:`int`. This might require changes in
+ your code for properly supporting 64-bit systems.
+
.. cfunction:: Py_ssize_t PySet_GET_SIZE(PyObject *anyset)