void Add(std::string const & s, NL::Node const & n) {
        size_t h{Hash(s)};
        size_t i{h & (Size - 1)};
        Link ** l{&Links[i]};
        while (*l) {
            l = &(*l)->Next;
        }
        *l = new(AllocSmall<Link>()) Link{h, n};
    }