text: #ifndef DAYTIME_SERVER_HPP
  #define DAYTIME_SERVER_HPP
  
  #include <ctime>
  #include <iostream>
  #include <string>
  #include <boost/bind.hpp>
  #include <boost/shared_ptr.hpp>
  #include <boost/enable_shared_from_this.hpp>
  #include <boost/asio.hpp>
  
  using boost::asio::ip::tcp;
  
  std::string make_daytime_string()
  {
    using namespace std; // For time_t, time and ctime;
    time_t now = time(0);
    return ctime(&now);
  }
  
  class tcp_connection
    : public boost::enable_shared_from_this<tcp_connection>
  {
  public:
    typedef boost::shared_ptr<tcp_connection> pointer;
  
    static pointer create(boost::asio::io_context& io_context)
    {
      return pointer(new tcp_connection(io_context));
    }
  
    tcp::socket& socket()
    {
      return socket_;
    }
  
    void start()
    {
      message_ = make_daytime_string();
  
      boost::asio::async_write(socket_, boost::asio::buffer(message_),
          boost::bind(&tcp_connection::handle_write, shared_from_this(),
            boost::asio::placeholders::error,
            boost::asio::placeholders::bytes_transferred));
    }
  
  private:
    tcp_connection(boost::asio::io_context& io_context)
      : socket_(io_context)
    {
    }
  
    void handle_write(const boost::system::error_code& /*error*/,
        size_t /*bytes_transferred*/)
    {
    }
  
    tcp::socket socket_;
    std::string message_;
  };
  
  class tcp_server
  {
  public:
    tcp_server(boost::asio::io_context& io_context)
      : acceptor_(io_context, tcp::endpoint(tcp::v4(), 13))
    {
      start_accept();
    }
  
  private:
    void start_accept()
    {
      tcp_connection::pointer new_connection =
        tcp_connection::create(acceptor_.get_executor().context());
  
      acceptor_.async_accept(new_connection->socket(),
          boost::bind(&tcp_server::handle_accept, this, new_connection,
            boost::asio::placeholders::error));
    }
  
    void handle_accept(tcp_connection::pointer new_connection,
        const boost::system::error_code& error)
    {
      if (!error)
      {
        new_connection->start();
      }
  
      start_accept();
    }
  
    tcp::acceptor acceptor_;
  };
  
  #endif