I have an issue with the assumption that if all parameters are forced to be prepended by -- instead of only one dash, that you would then convert the -- to a single dash and have issues with single-dashed strings, when all other parameters are dual-dashed. This is especially crazy if the user specifies that prefix_chars="--" when creating the parser! You wouldn't mix up ** with * just because it's a two char string, so why do this for -- in this day and age when parameters can take on very different and complicated structures?!