MF_IMPL_NDBM
if (bitset(MF_IMPL_NDBM, map->map_mflags))
if (bitset(MF_IMPL_NDBM, map->map_mflags))
map->map_mflags |= MF_IMPL_NDBM;
map->map_mflags &= ~MF_IMPL_NDBM;
if (bitset(MF_IMPL_NDBM, map->map_mflags))
map->map_mflags &= ~MF_IMPL_NDBM;