From: Daniel Martin <martin@...>
Date: 2006-07-15T19:49:38+09:00
Subject: Re: Preferred monkeypatching technique

Eric Hodel <drbrain@segment7.net> writes:

> You don't need a mutex.
>
> class Symbol
>   @gensym_count = 0
>   def self.gensym
>     ("__gensym__%X" % @gensym_count += 1).intern
>   end
> end

Okay, but now if two different files include this exact code, you're
re-generating the same symbols.  This is why I used ||=, making your
code:

class Symbol
  @gensym_count ||= 0
  def Symbol.gensym
    ("__gensym__%X" % @gensym_count += 1).intern
  end
end

At the very least, two people using the same exact code to define
gensym shouldn't collide with each other.