Quicksort in Ruby

gistfile1.rb

class Array
  def quick_sort
    return self if length <= 1
    base = pop #pivot
    smaller, bigger = partition { |v| v <= base }
    push base #for keep original
    smaller.quick_sort + [base] + bigger.quick_sort
  end
end

ar = [5,3,2,7,10,2,12]
p ar.quick_sort
# [2, 2, 3, 5, 7, 10, 12]