Cuthill Mckee Ordering Algorithm

On the Graph documentation it is shown an example showing how to get reverse Cuthill-McKee ordering. It uses rbegin() to get it. My question is: how to get the non-reverse Cuthill-McKee ordering. It still give the reverse ordering even after I use begin(). Did I do something wrong? Can someone advise me the correct one (with example, if possible). Erman