From: Kamil <kamil.kukura@...>
Date: 2007-11-14T00:35:01+09:00
Subject: Handy method Object#in?

I wish there would be this simple method in the core:

class Object
  def in?(an_array)
    an_array.include?(self)
  end
end

Having that it's nice to write:

a = %w(hello world out there)
puts 'world'.in?(a)

And it works with Interval instance too.