case BACKREF: /* the Feature From The Black Lagoon */
INSIST(type != LACON, REG_ESUBREG);
INSIST(v->nextvalue < v->nsubs, REG_ESUBREG);
- INSIST(v->subs[v->nextvalue] != NULL, REG_ESUBREG);
+ INSIST(v->subs[(int)v->nextvalue] != NULL, REG_ESUBREG);
NOERR();
assert(v->nextvalue > 0);
atom = subre(v, 'b', BACKR, lp, rp);