note that future_builtin's map is not quite like python 3's (closes #19363)

Patch by Gareth Rees.

diff --git a/Doc/library/future_builtins.rst b/Doc/library/future_builtins.rst
index 04f20526cab1d636abf71fa6d3a2a1b59a73e746..62392eb4b62be245a54ad7970a9cef1cde1d82d2 100644 (file)
--- a/Doc/library/future_builtins.rst
+++ b/Doc/library/future_builtins.rst
@@ -50,6 +50,11 @@ Available builtins are:
 
    Works like :func:`itertools.imap`.
 
+   .. note::
+
+      In Python 3, :func:`map` does not accept ``None`` for the
+      function argument.
+
 .. function:: oct(object)
 
    Works like the built-in :func:`oct`, but instead of :meth:`__oct__` it will