Kinda

kinda.rb

require "levenshtein"

class Object
  def kinda?(klass)
    Levenshtein.normalized_distance(self.class.to_s, klass.to_s) < 0.85
  end
end

>> "foo".class
=> String
>> "foo".is_a?(Struct)
=> false
>> "foo".kinda?(Struct)
=> true
>> "foo".kinda?(Fixnum)
=> false

>> 1.class
=> Fixnum
>> 1.is_a?(Float)
=> false
>> 1.kinda?(Float)
=> true
>> 1.kinda?(String)
=> false