![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
// // reference_counted.cpp // ~~~~~~~~~~~~~~~~~~~~~ // // Copyright (c) 2003-2014 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 <boost/asio.hpp> #include <boost/bind.hpp> #include <boost/enable_shared_from_this.hpp> #include <boost/shared_ptr.hpp> #include <iostream> #include <vector> using boost::asio::ip::tcp; // A reference-counted non-modifiable buffer class. class shared_const_buffer { public: // Construct from a std::string. explicit shared_const_buffer(const std::string& data) : data_(new std::vector<char>(data.begin(), data.end())), buffer_(boost::asio::buffer(*data_)) { } // Implement the ConstBufferSequence requirements. typedef boost::asio::const_buffer value_type; typedef const boost::asio::const_buffer* const_iterator; const boost::asio::const_buffer* begin() const { return &buffer_; } const boost::asio::const_buffer* end() const { return &buffer_ + 1; } private: boost::shared_ptr<std::vector<char> > data_; boost::asio::const_buffer buffer_; }; class session : public boost::enable_shared_from_this<session> { public: session(boost::asio::io_service& io_service) : socket_(io_service) { } tcp::socket& socket() { return socket_; } void start() { using namespace std; // For time_t, time and ctime. time_t now = time(0); shared_const_buffer buffer(ctime(&now)); boost::asio::async_write(socket_, buffer, boost::bind(&session::handle_write, shared_from_this())); } void handle_write() { } private: // The socket used to communicate with the client. tcp::socket socket_; }; typedef boost::shared_ptr<session> session_ptr; class server { public: server(boost::asio::io_service& io_service, short port) : io_service_(io_service), acceptor_(io_service, tcp::endpoint(tcp::v4(), port)) { session_ptr new_session(new session(io_service_)); acceptor_.async_accept(new_session->socket(), boost::bind(&server::handle_accept, this, new_session, boost::asio::placeholders::error)); } void handle_accept(session_ptr new_session, const boost::system::error_code& error) { if (!error) { new_session->start(); } new_session.reset(new session(io_service_)); acceptor_.async_accept(new_session->socket(), boost::bind(&server::handle_accept, this, new_session, boost::asio::placeholders::error)); } private: boost::asio::io_service& io_service_; tcp::acceptor acceptor_; }; int main(int argc, char* argv[]) { try { if (argc != 2) { std::cerr << "Usage: reference_counted <port> "; return 1; } boost::asio::io_service io_service; using namespace std; // For atoi. server s(io_service, atoi(argv[1])); io_service.run(); } catch (std::exception& e) { std::cerr << "Exception: " << e.what() << " "; } return 0; }
------
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
void main() {}
======
#include <iostream> int main() {}