class Fixnum

def bit_length
  n = if self >= 0
    self + 1
  else
    -self
  end
  (0...8 * size).bsearch{|i| n <= (1 << i) }
end

def div(n)
  (self / n).to_i
end

def dup
  self
end

def fdiv(n)
  to_f / n
end