Provide links to Python source where the code is short, readable and
informative adjunct to the docs.  Forward-port of Raymond's r86225 and
r86245 using the new source reST role added in #10334.
diff --git a/Doc/library/filecmp.rst b/Doc/library/filecmp.rst
index f57dcce..d6cdd29 100644
--- a/Doc/library/filecmp.rst
+++ b/Doc/library/filecmp.rst
@@ -10,6 +10,11 @@
 with various optional time/correctness trade-offs. For comparing files,
 see also the :mod:`difflib` module.
 
+.. seealso::
+
+   Latest version of the :source:`filecmp Python source code
+   <Lib/filecmp.py>`
+
 The :mod:`filecmp` module defines the following functions: