Just out of curiosity, why can't I say:

irb(main):001:0> class << 1
irb(main):002:1> def meth
irb(main):003:2> end
irb(main):004:1> end
TypeError: no virtual class for Fixnum
        from (irb):1

?

Is this a hole in the pure OO of ruby, or is there an OO explanation?