From: Josh Rendek <josh@...>
Date: 2012-08-28T13:18:50+09:00
Subject: Re: A Ruby class is never closed

A really simple way to ensure a class doesn't get modified:

class Foo
   def Foo.method_added(name)
     raise "This class is closed for modification"
   end
end

class Foo
   def testing
   end
end




On 8/27/12 5:18 PM, Ryan Davis wrote:
> On Aug 27, 2012, at 14:03 , Robert Klemme <shortcutter@googlemail.com> wrote:
>
>> Well, you may find the point subtle but the class you assign to X the
>> second time is not the same as the one which was assigned the first
>> time.  The important bit here is that they do not share identity even
>> though they can be accessed via the same constant (but at different
>> times).  This has serious implications especially if there are
>> instances around of class #1: If you ask them for their class and try
>> to modify it, the program will fail (unless there are some
>> modifications possible which I have overlooked - see above).
> gem install change_class
>
> o.class = SomeOtherClass
>
> done
>
>