_SL_CHUNKSIZE
sl->sl_max = _SL_CHUNKSIZE;
sl->sl_max += _SL_CHUNKSIZE;
sl->sl_max = _SL_CHUNKSIZE;
new = reallocarray(sl->sl_str, (sl->sl_max + _SL_CHUNKSIZE),
sl->sl_max += _SL_CHUNKSIZE;