module Enumerable

def drop_while

Standard in Ruby 1.8.7+. See official documentation[http://ruby-doc.org/core-1.9/classes/Enumerable.html] 
def drop_while
  return to_enum(:drop_while) unless block_given?
  ary = []
  dropping = true
  each do |obj|
    ary << obj unless dropping &&= yield(obj)
  end
  ary
end