boost::asio 序列16: tcp::socket 和 udp::socket & socket_basic

           reactive_socket_service_base          execution_context_service_base <reative_socket_service<Porotocol>>  

                                                                \                         |

                                                                reactive_socket_service<Protocol>

                                                                                    |                                                                          

                                  socket_basic             io_object_impl<Protocol, Executor>  (成員變量)               system_executor            

                                                              \                   |                                                                                      |

                                                                   basic_socket<Protocol, Executor>    其中 Exector =====>     executor 

                                                                         /                         \                                                                       

                          basic_stream_socket<tcp>                 basic_datagram_socket<udp>                        

socket_basic:定義socket共用的一些數據類型和選項

shutdown_type	shutdown_receive = BOOST_ASIO_OS_DEF(SHUT_RD),     shutdown_send = BOOST_ASIO_OS_DEF(SHUT_WR),     shutdown_both = BOOST_ASIO_OS_DEF(SHUT_RDWR)
message_flags	BOOST_ASIO_STATIC_CONSTANT(int,       message_peek = BOOST_ASIO_OS_DEF(MSG_PEEK));   BOOST_ASIO_STATIC_CONSTANT(int,       message_out_of_band = BOOST_ASIO_OS_DEF(MSG_OOB));   BOOST_ASIO_STATIC_CONSTANT(int,       message_do_not_route = BOOST_ASIO_OS_DEF(MSG_DONTROUTE));   BOOST_ASIO_STATIC_CONSTANT(int,       message_end_of_record = BOOST_ASIO_OS_DEF(MSG_EOR));
wait_type	enum wait_type   {     /// Wait for a socket to become ready to read.     wait_read,     /// Wait for a socket to become ready to write.     wait_write,     /// Wait for a socket to have error conditions pending.     wait_error   };
SOL_SOCKET/SO_BROADCAST	typedef boost::asio::detail::socket_option::boolean<     BOOST_ASIO_OS_DEF(SOL_SOCKET), BOOST_ASIO_OS_DEF(SO_BROADCAST)>       broadcast;
SOL_SOCKET/SO_DEBUG	typedef boost::asio::detail::socket_option::boolean<     BOOST_ASIO_OS_DEF(SOL_SOCKET), BOOST_ASIO_OS_DEF(SO_DEBUG)> debug;
SOL_SOCKET/SO_DONTROUTE	typedef boost::asio::detail::socket_option::boolean<     BOOST_ASIO_OS_DEF(SOL_SOCKET), BOOST_ASIO_OS_DEF(SO_DONTROUTE)>       do_not_route;
SOL_SOCKET/SO_KEEPALIVE	typedef boost::asio::detail::socket_option::boolean<     BOOST_ASIO_OS_DEF(SOL_SOCKET), BOOST_ASIO_OS_DEF(SO_KEEPALIVE)> keep_alive;
SOL_SOCKET/SO_SNDBUF	typedef boost::asio::detail::socket_option::integer<     BOOST_ASIO_OS_DEF(SOL_SOCKET), BOOST_ASIO_OS_DEF(SO_SNDBUF)>       send_buffer_size;
SOL_SOCKET/SO_SNDLOWAT	typedef boost::asio::detail::socket_option::integer<     BOOST_ASIO_OS_DEF(SOL_SOCKET), BOOST_ASIO_OS_DEF(SO_SNDLOWAT)>       send_low_watermark;
SOL_SOCKET/SO_RCVBUF	typedef boost::asio::detail::socket_option::integer<     BOOST_ASIO_OS_DEF(SOL_SOCKET), BOOST_ASIO_OS_DEF(SO_RCVBUF)>       receive_buffer_size;
SOL_SOCKET/SO_RCVLOWAT	typedef boost::asio::detail::socket_option::integer<     BOOST_ASIO_OS_DEF(SOL_SOCKET), BOOST_ASIO_OS_DEF(SO_RCVLOWAT)>       receive_low_watermark;
SOL_SOCKET/SO_REUSEADDR	typedef boost::asio::detail::socket_option::boolean<     BOOST_ASIO_OS_DEF(SOL_SOCKET), BOOST_ASIO_OS_DEF(SO_REUSEADDR)>       reuse_address;
SOL_SOCKET/SO_LINGER	typedef boost::asio::detail::socket_option::linger<     BOOST_ASIO_OS_DEF(SOL_SOCKET), BOOST_ASIO_OS_DEF(SO_LINGER)>       linger;
SOL_SOCKET/SO_OOBINLINE	typedef boost::asio::detail::socket_option::boolean<     BOOST_ASIO_OS_DEF(SOL_SOCKET), BOOST_ASIO_OS_DEF(SO_OOBINLINE)>       out_of_band_inline;
Socket option to report aborted connections on accept	typedef boost::asio::detail::socket_option::boolean<     boost::asio::detail::custom_socket_option_level,     boost::asio::detail::enable_connection_aborted_option>     enable_connection_aborted;
the FIONREAD IO control command	typedef boost::asio::detail::io_control::bytes_readable bytes_readable;