GLib.OptionArgFunc

function onOptionArgFunc(option_name: String, value: String, data: void): Boolean {
}

The type of function to be passed as callback for GLib.OptionArg.callback options.

option_name: The name of the option being parsed. This will be either a single dash followed by a single letter (for a short name) or two dashes followed by a long option name.
value: The value to be parsed.
data: User data added to the GLib.OptionGroup containing the option when it was created with GLib.OptionGroup.new
Returns: true if the option was successfully parsed, false if an error occurred, in which case @error should be set with GLib.set_error