class Connection
{
public:
  typedef boost::shared_ptr<Connection> pointer;
  static pointer create(boost::asio::io_service& io_service){return pointer(new Connection(io_service));}

  explicit Connection(boost::asio::io_service& io_service);
  virtual ~Connection();
  boost::asio::ip::tcp::socket& socket();

  -->>>virtual void OnConnected()=0;
  void Send(uint8_t* buffer, int length);
  bool Receive();
private:
  void handler(const boost::system::error_code& error, std::size_t bytes_transferred );
  boost::asio::ip::tcp::socket socket_;
};

quando estou tentando usar o void virtual OnConnected () = 0; isso me dá esse erro idiota idk que está errado !!!

1   IntelliSense: object of abstract class type "Connection" is not allowed:    d:\c++\ugs\accountserver\connection.h   17

whats errado e como posso corrigi-lo enquanto na minha antiga classe de conexão estava funcionando bem !!

class Connection
{
    public:
        explicit Connection(int socket);
        virtual ~Connection();

        virtual void OnConnected() =0;
        virtual int Send(uint8_t* buffer, int length);
        bool Receive();
        int getSocket() const;
        void Disconnect();
    protected:
        virtual void OnReceived(uint8_t* buffer, int len) = 0;
    private:
        int m_socket;
        bool disconnecting;
};

então o que está faltando aqui !!