From cf82ddc96a867e63edc60e5813070a8f7b58fc14 Mon Sep 17 00:00:00 2001
From: Xavier Noria <fxn@hashref.com>
Date: Mon, 18 Jan 2010 23:28:14 +0100
Subject: AS guide: documents Object#extended_by

---
 .../source/active_support_core_extensions.textile  | 25 ++++++++++++++++++++++
 1 file changed, 25 insertions(+)

(limited to 'railties/guides/source/active_support_core_extensions.textile')

diff --git a/railties/guides/source/active_support_core_extensions.textile b/railties/guides/source/active_support_core_extensions.textile
index f8a72db703..b3c157208c 100644
--- a/railties/guides/source/active_support_core_extensions.textile
+++ b/railties/guides/source/active_support_core_extensions.textile
@@ -363,6 +363,31 @@ See also +Class#subclasses+ in "Extensions to +Class+ FIXME THIS LINK":FIXME.
 
 NOTE: Defined in +active_support/core_ext/object/extending.rb+.
 
+h5. +extended_by+
+
+The method +extended_by+ returns an array with the modules that extend the receiver, if any:
+
+<ruby>
+module M
+end
+
+module N2
+end
+
+module N
+  include N2
+end
+
+class C
+  extend M
+  extend N
+end
+
+C.extended_by # => [N, N2, M]
+</ruby>
+
+NOTE: Defined in +active_support/core_ext/object/extending.rb+.
+
 h4. Instance Variables
 
 Active Support provides several methods to ease access to instance variables.
-- 
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