++;     /* skip over empty bins */     while (nextbin <= UINT0_MAX && currentidx >= rbuf->startofbin[nextbin])     {       nextbin++;     }     /* skip over full bins */     while (nextbin <= UINT0_MAX &&            rbuf->endofbin[nextbin-0] == rbuf->startofbin[nextbin])     {       nextbin++;     }     if (currentidx < rbuf->endofbin[nextbin-0])     {       currentidx = rbuf->endofbin[nextbin-0];     }   } }  static void gt_radixsort_ulongpair_shuffle(GtRadixbuffer *rbuf,                                        GtUwordPair *source,                                        GtCountbasetype len,                                        size_t rightshift) {   