Using: ruby 1.8.6 (2007-03-13 patchlevel 0) [i386-mswin32]
and: ruby 1.8.4 (2006-02-24) [x86_64-linux]

I can't find Enumerable#each_cons in either version -- always a
NoMethodError:

irb(main):001:0> [1, 2, 3].cons(2) {|a| p a}
=> NoMethodError: undefined method `cons' for [1, 2, 3]:Array from
(irb):1

irb(main):002:0> (1..10).each_cons(2) {|a| p a}
=> NoMethodError: undefined method `each_cons' for 1..10:Range from
(irb):2

Am I missing something? (Besides #each_cons, of course.)

Jeremy