class Optimist::Option

def description_with_default
  return desc unless default
  default_s = case default
              when $stdout   then '<stdout>'
              when $stdin    then '<stdin>'
              when $stderr   then '<stderr>'
              when Array
                default.join(', ')
              else
                default.to_s
              end
  defword = desc.end_with?('.') ? 'Default' : 'default'
  return "#{desc} (#{defword}: #{default_s})"
end