# class Gem::OptionParser::Switch::OptionalArgument

`Switch` that can omit argument.

### Public Instance Methods

parse(arg, argv, &error) click to toggle source

Parses argument if given, or uses default value.

    # File lib/rubygems/optparse/lib/optparse.rb, line 723
    def parse(arg, argv, &error)
      if arg
        conv_arg(*parse_arg(arg, &error))
      else
        conv_arg(arg)
      end
    end