boost::asio::buffers

#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    {        boost::asio::io_service io_service;        using namespace std; // For atoi.        server s(io_service, 6001);        io_service.run();    }    catch (std::exception& e)    {        std::cerr << "Exception: " << e.what() << "\n";    }    return 0;}