Is that right?

irb(main):001:0> i = 1.0/0
=> Infinity
irb(main):002:0> -i.to_s
NoMethodError: undefined method `-@' for "Infinity":String
        from (irb):2

Doesn't do this for other numbers.

irb(main):004:0> -4.0.to_s
=> "-4.0"

T.