buffered_readers[new_socket_fd].reset([new_socket_fd, client_addr,
                                                           &subscriber_manager, &topic_manager, &buffered_readers]
                                                          (const tcp_message_t& tcp_message)
                    {
                        switch(tcp_message.mtype)
                        {
                        case identity:
                        {
                            std::string client_id = tcp_message.topic;

                            subscriber_manager.add_subscriber(new_socket_fd, client_addr, client_id);
                            topic_manager.send_missed_messages(client_id);

                            udp_message_t umsg = {};
                            strcpy(umsg.topic_name, "welcome");
                            strcpy(umsg.message, "hello world!");
                            umsg.type = type_string;

                            message_t welcome_msg(client_addr, umsg);
                            tcp_message_t tmp = welcome_msg.to_tcp_message(publish);
                            send(new_socket_fd, &tmp, tmp.len, 0);

                            buffered_readers[new_socket_fd].reset([client_id, &subscriber_manager, &topic_manager]
                                                                  (const tcp_message_t& tcp_message)
                            {
                                switch(tcp_message.mtype)
                                {
                                case subscribe:
                                {
                                    topic_manager.subscribe(client_id, tcp_message.topic, tcp_message.sf);
                                    printf("Client %s has subscribed to topic %s with s&f %d\n",
                                           client_id.c_str(), tcp_message.topic, tcp_message.sf);

                                    break;
                                }
                                case unsubscribe:
                                {
                                    topic_manager.unsubscribe(client_id, tcp_message.topic);
                                    printf("Client %s has unsubscribed from topic %s\n",
                                           client_id.c_str(), tcp_message.topic);
                                    break;
                                }
                                default:
                                {
                                    break;
                                }
                                }
                            });

                            break;
                        }
                        default:
                        {
                            break;
                        }
                        }
                    });
                }