From: Joel VanderWerf <joelvanderwerf@...>
Date: 2010-06-06T09:02:17+09:00
Subject: Re: 1.9 warning for 'private' and possible bug

Rein Henrichs wrote:
> On 2010-06-05 15:55:20 -0700, Joel VanderWerf said:
>>
>> No. The original code is controlling access to the method
>> Module#attr_accessor. Your code is controlling access to
>> PrivateAccessor#foo.
> 
> Not exactly. Methods created by attr_accessor will have its visibility. 
> Your code makes attr_accessor private, which is why accessors created 
> with it are also private. You can also demonstrate by writing your own 
> attr_accessor from scratch.

Did you try that? The following code runs the same in 1.8 and 1.9:

   class C
     class << self
       def my_attr_accessor(name)
         define_method name do
           puts "foo"
         end
       end
       private :my_attr_accessor
     end

     my_attr_accessor :bar
   end

   C.new.bar # => foo


Anyway, attr_accessor is already a private module method in ruby, but 
the instance methods it creates are not, by default.