std::pair<iterator, bool> try_emplace(key_type&& k, _Args&&... args) {
        auto p = std::pair<key_type, mapped_type>{std::move(k), mapped_type(std::forward<_Args>(args)...)};
        const size_type n = hash(p.first);
        const size_type index = n % act_size;
        if (load_factor() >= max_load_factor()) {
            rehash(state.size() * 2);
        }
        size_t i = index;
        while (true) {
            if (state[i] == 0) {
                new(data + index) value_type{p.first, p.second};
                state[i] = 1;
                exist_size++;
                act_size++;
                return std::pair<iterator, bool>(iterator(data, &state, i), true);
            }
            else if (equal_key(data[i].first, p.first)) {
                if (state[i] == 1) {
                    return std::pair<iterator, bool>(iterator(data, &state, i), false);
                }
                else {
                    data[i].second = p.second;
                    state[i] = 1;
                    exist_size++;
                    return std::pair<iterator, bool>(iterator(data, &state, i), true);
                }
            }
            i++;
            if (i == state.size()) {
                i = 0;
            }
            if (i == index) {
                break;
            }
        }
    }