From: Mike Depot <mdepot@...>
Date: 2002-05-29T09:50:18+09:00
Subject: Singleton Class

I would like to create a singleton class (not to be confused with singleton
methods...)

I've seen the construct below, but I've read it's not thread safe.  First,
why isn't it?  Second, is there a more proper way to do this, perhaps that's
even thread safe?

class SingletonClass

  private_class_method :new

     def SingletonClass.create(*args, &block)
        @@singleton = new(*args, &block) unless @@singleton
        return @@singleton
     end
end