Static OPTION_REMAINING 

pub static OPTION_REMAINING: &GStr

If a long option in the main group has this name, it is not treated as a regular option. Instead it collects all non-option arguments which would otherwise be left in argv. The option must be of type OptionArg::Callback, OptionArg::StringArray or OptionArg::FilenameArray.

Using OPTION_REMAINING instead of simply scanning argv for leftover arguments has the advantage that GOption takes care of necessary encoding conversions for strings or filenames.