"num in [1,2,3,4]" in a cool way?

< ^ > P N |<>|^_>< --- | ~ ...Help

Hi, AFAIK in Ruby the only (or the "coolest") way to do something as:

  if num in [1,2,3,4]

is by doing:

  if [1,2,3,4].index(num)

Is it? any other "cooler" way? Thanks.

-- 
Iñaki Baz Castillo