socket中的option

/// Set an option on the socket.
/**
* This function is used to set an option on the socket.
*
* @param option The new option value to be set on the socket.
*
* @throws boost::system::system_error Thrown on failure.
*
* @sa SettableSocketOption @n
* boost::asio::socket_base::broadcast @n
* boost::asio::socket_base::do_not_route @n
* boost::asio::socket_base::keep_alive @n
* boost::asio::socket_base::linger @n
* boost::asio::socket_base::receive_buffer_size @n
* boost::asio::socket_base::receive_low_watermark @n
* boost::asio::socket_base::reuse_address @n
* boost::asio::socket_base::send_buffer_size @n
* boost::asio::socket_base::send_low_watermark @n
* boost::asio::ip::multicast::join_group @n
* boost::asio::ip::multicast::leave_group @n
* boost::asio::ip::multicast::enable_loopback @n
* boost::asio::ip::multicast::outbound_interface @n
* boost::asio::ip::multicast::hops @n
* boost::asio::ip::tcp::no_delay
*
* @par Example
* Setting the IPPROTO_TCP/TCP_NODELAY option:
* @code
* boost::asio::ip::tcp::socket socket(io_service);
* ...
* boost::asio::ip::tcp::no_delay option(true);
* socket.set_option(option);
* @endcode
*/
template <typename SettableSocketOption>
void set_option(const SettableSocketOption& option)
{
boost::system::error_code ec;
this->get_service().set_option(this->get_implementation(), option, ec);
boost::asio::detail::throw_error(ec, "set_option");
}