# File rquantum.rb, line 583
  def measure from=nil, to=nil
    if !from && !to
      from=0
      to=@reg.size-1
    elsif !to
      to=from
    end
    result = 0
    w = 1
    to.downto from do |i|
      result += w if @reg[i].measure == 1
      w *= 2
    end
    result
  end