# Must all option be given before the first argument?
	#
	# When set to `false` (the default), options of the command line are
	# all parsed until the end of the list of arguments or until "--" is met (in this case "--" is discarded).
	#
	# When set to `true` options are parsed until the first non-option is met.
	var options_before_rest = false is writable