# File lib/more/facets/argvector.rb, line 175
  def preflags
    preopts, remainder = *parse_preoptions(argv)
    f = []
    preopts.each do |k, v|
      if TrueClass===v or FalseClass===v  # not that it's ever false
        f << k
      end
    end
    return f
  end