Don't subclass Struct classes

gistfile1.rb

# Don't subclass Struct classes
# instead of:
class Wheel < Struct.new(:rim, :tire)
  #...
end

#use

Wheel2 = Struct.new(:rim, :tire) do
  # ...
end

# When subclassing from Struct.new(...), you actually do that:
# Wheel = Class.new(Struct.new(...)), i.e. create two classes instead one and pollute ancestors chain with anonymous class:
p Wheel.ancestors # => [Wheel, #<Class:0x00000000ce7c28>, Struct, Enumerable, Object, Kernel, BasicObject]
p Wheel2.ancestors # => [Wheel2, Struct, Enumerable, Object, Kernel, BasicObject]

Summary of http://gistflow.com/posts/566-don-t-subclass-struct-classes-please