3 files changed, 14 insertions, 4 deletions
diff --git a/activesupport/CHANGELOG b/activesupport/CHANGELOG
index 6b7044aeae..6c1e6185af 100644
--- a/activesupport/CHANGELOG
+++ b/activesupport/CHANGELOG
@@ -1,5 +1,7 @@
 *Rails 3.2.0 (unreleased)*
 
+* Added instance_accessor: false as an option to Class#cattr_accessor and friends [DHH]
+
 * Removed ActiveSupport::SecureRandom in favour of SecureRandom from the standard library [Jon Leighton]
 
 * ActiveSupport::OrderedHash now has different behavior for #each and
diff --git a/activesupport/lib/active_support/core_ext/class/attribute_accessors.rb b/activesupport/lib/active_support/core_ext/class/attribute_accessors.rb
index a903735acf..268303aaf2 100644
--- a/activesupport/lib/active_support/core_ext/class/attribute_accessors.rb
+++ b/activesupport/lib/active_support/core_ext/class/attribute_accessors.rb
@@ -17,6 +17,7 @@ require 'active_support/core_ext/array/extract_options'
 #
 # To opt out of the instance writer method, pass :instance_writer => false.
 # To opt out of the instance reader method, pass :instance_reader => false.
+# To opt out of both instance methods, pass :instance_accessor => false.
 #
 #   class Person
 #     cattr_accessor :hair_colors, :instance_writer => false, :instance_reader => false
@@ -38,7 +39,7 @@ class Class
         end
       EOS
 
-      unless options[:instance_reader] == false
+      unless options[:instance_reader] == false || options[:instance_accessor] == false
         class_eval(<<-EOS, __FILE__, __LINE__ + 1)
           def #{sym}
             @@#{sym}
@@ -61,7 +62,7 @@ class Class
         end
       EOS
 
-      unless options[:instance_writer] == false
+      unless options[:instance_writer] == false || options[:instance_accessor] == false
         class_eval(<<-EOS, __FILE__, __LINE__ + 1)
           def #{sym}=(obj)
             @@#{sym} = obj
diff --git a/activesupport/test/core_ext/class/attribute_accessor_test.rb b/activesupport/test/core_ext/class/attribute_accessor_test.rb
index 456f4b7948..6b50f8db37 100644
--- a/activesupport/test/core_ext/class/attribute_accessor_test.rb
+++ b/activesupport/test/core_ext/class/attribute_accessor_test.rb
@@ -5,8 +5,9 @@ class ClassAttributeAccessorTest < Test::Unit::TestCase
   def setup
     @class = Class.new do
       cattr_accessor :foo
-      cattr_accessor :bar,  :instance_writer => false
-      cattr_reader   :shaq, :instance_reader => false
+      cattr_accessor :bar,  :instance_writer   => false
+      cattr_reader   :shaq, :instance_reader   => false
+      cattr_accessor :camp, :instance_accessor => false
     end
     @object = @class.new
   end
@@ -35,4 +36,10 @@ class ClassAttributeAccessorTest < Test::Unit::TestCase
     assert_respond_to @class, :shaq
     assert !@object.respond_to?(:shaq)
   end
+
+  def test_should_not_create_instance_accessors
+    assert_respond_to @class, :camp
+    assert !@object.respond_to?(:camp)
+    assert !@object.respond_to?(:camp=)
+  end
 end