There's also rustlex [1] that have been around for a while and provides rust stable v1.0 support through syntex [2]. I use it for a handlebars implementation [3].
The C comment example seems more simply solved using non-greedy matching. Is that not done because the parser absolutely does not support non-greedy (or minimal-munch) matching?
The parsing of C-style comments is a sort of standard example to demonstrate some additional features you have available when your lexer-generator is implemented using regular expression derivatives.