...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
// // server.cpp // ~~~~~~~~~~ // // Copyright (c) 2003-2008 Christopher M. Kohlhoff (chris at kohlhoff dot com) // // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) // #include <ctime> #include <iostream> #include <string> #include <boost/array.hpp> #include <boost/bind.hpp> #include <boost/shared_ptr.hpp> #include <boost/asio.hpp> using boost::asio::ip::udp; std::string make_daytime_string() { using namespace std; // For time_t, time and ctime; time_t now = time(0); return ctime(&now); } class udp_server { public: udp_server(boost::asio::io_service& io_service) : socket_(io_service, udp::endpoint(udp::v4(), 13)) { start_receive(); } private: void start_receive() { socket_.async_receive_from( boost::asio::buffer(recv_buffer_), remote_endpoint_, boost::bind(&udp_server::handle_receive, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } void handle_receive(const boost::system::error_code& error, std::size_t /*bytes_transferred*/) { if (!error || error == boost::asio::error::message_size) { boost::shared_ptr<std::string> message( new std::string(make_daytime_string())); socket_.async_send_to(boost::asio::buffer(*message), remote_endpoint_, boost::bind(&udp_server::handle_send, this, message, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); start_receive(); } } void handle_send(boost::shared_ptr<std::string> /*message*/, const boost::system::error_code& /*error*/, std::size_t /*bytes_transferred*/) { } udp::socket socket_; udp::endpoint remote_endpoint_; boost::array<char, 1> recv_buffer_; }; int main() { try { boost::asio::io_service io_service; udp_server server(io_service); io_service.run(); } catch (std::exception& e) { std::cerr << e.what() << std::endl; } return 0; }