gistfile1.rb

module Enumerable
  class Proxy
    instance_methods.each do |method|
      next if method.to_s =~ /\A__(id|send)__\Z/
      undef_method(method)
    end
    def initialize(target, method=:map)
      @target, @method = target, method
    end
    private
    def method_missing(method, *args, &block)
      @target.__send__(@method) do |item|
        item.__send__(method, *args, &block)
      end
    end
  end

  def every(method=:map)
    Proxy.new(self, method)
  end
end

# >> [1,2,3].every.to_s
# => ['1','2','3']