From: Matthias Georgi <matti.georgi@...>
Date: 2005-11-26T04:12:27+09:00
Subject: Re: Faster way to pick the every other array member?

Another one:

module Enumerable
  def select_with_index
    index = 0
    select { |item|
      res = yield item, index
      index += 1
      res
    }
  end
end

[1,2,3,4,5,6,7].select_with_index {|n, i| i % 2 == 1 }

I know this is basically the same, but you can see clearly what is
happening.