Question

我遇到了async_read_some

的问题

我使用async_write_some进行编译，结果很好。

但是，我尝试使用async_read_some进行编译，

并提出了奇怪的错误，它可以找到正确的方法。

我是新手，以促进世界.Plz帮我解决这些问题。

提前致谢。

Opps编译器错误就像这样

错误：没有匹配函数来调用＆＃39; ws_async_tcp_connection :: async_recv_msg_some（boost :: asio :: mutable_buffers_1，boost :: _ bi :: bind_t，boost :: _ bi :: list3，boost :: arg＆lt; 1＆gt; ;（）（），boost :: arg＆lt; 2＆gt;（）（）＆gt;＆gt;）＆＃39; /home/chris/proto/inc/ws_async_tcp_connection.h:119：注意：候选人是：void ws_async_tcp_connection :: async_recv_msg_some（T＆amp;，Handler）[使用T = boost :: asio :: mutable_buffers_1，Handler = boost :: _ bi：：bind_t，boost :: _ bi :: list3，boost :: arg＆lt; 1＆gt; （）（），boost :: arg＆lt; 2＆gt; （）（）＆GT; ＆GT;]

header 
-----------------------------------------------------------------------------------
class ws_async_tcp_connection{
    boost::asio::ip::tcp::socket socket_;
public:

    ws_async_tcp_connection(boost::asio::io_service& arg_io_service)
        : socket_(arg_io_service){}


    /*
    *   destructor
    */      
    ~ws_async_tcp_connection(){
        shutdown();
    }


    /*
    *   connect method
    *       : binding connection handler -> handle_connect
    */
    void connect(const std::string& host_addr, const std::string& port_no){
        boost::asio::ip::tcp::resolver resolver_(socket_.get_io_service());
        boost::asio::ip::tcp::resolver::query query_(boost::asio::ip::tcp::v4(), host_addr, port_no);
        boost::asio::ip::tcp::resolver::iterator end_point_iter = resolver_.resolve(query_);
        boost::asio::async_connect(socket_, end_point_iter, 
            boost::bind(&ws_async_tcp_connection::handle_connect, this, boost::asio::placeholders::error));
    }


    /*
    *   handle_connect
    *       : handle after the connect method called
    */
    void handle_connect(const boost::system::error_code& ec){
        if(!ec){
            // successfully established the connection - maybe print the remote ip, port
            /*  getting the remote_endpoint ip, port
            std::string connected_server_ip = socket_.remote_endpoint().address().to_string();
            unsigned short connected_server_port = socket_.remote_endpoint().port();
            */
        }
        else{
            // error handling - maybe use Logger class to print the error
            shutdown();
        }
    }


    /*
    *   set_option
    *       : set option for the tcp socket
    */
    template<typename SettableSocketOption>
    void set_option(const SettableSocketOption& option){
        // if performance is poor, then let's try no_delay option(true);
        /* keepalive option
            boost::asio::socket_base::keep_alive option(true);
            socket.set_option(option);
        */
        socket_.set_option(option);
    }


    /*
    *   is_open
    *       : socket is opened or not
    */
    bool is_open(){
        return socket_.is_open();
    }

    /*
    *   async_send_msg
    *       : send msg (warning! : will be blocked until the exact bytes you ask for are transmitted)
    */
    template <typename T, typename Handler> 
    void async_send_msg(const T& send_buf, Handler handler){
        boost::asio::async_write(socket_, send_buf, handler);
    }


    /*
    *   async_recv_msg
    *       : recv msg (warning! : will be blocked until the exact bytes you ask for are transmitted)
    */
    template <typename T, typename Handler> 
    void async_recv_msg(T& recv_buf, Handler handler){
        boost::asio::async_read(socket_, recv_buf, handler);
    }

    /*
    *   async_send_msg_some
    *       : send msg
    */  
    template <typename T, typename Handler> 
    void async_send_msg_some(const T& send_buf, Handler handler){
        socket_.async_write_some(send_buf, handler);
    }


    /*
    *   async_recv_msg_some
    *       : recv msg (Typically use this if you don't have to receive the exact numbers of bytes)
    */
    template <typename T, typename Handler> 
    void async_recv_msg_some(T& recv_buf, Handler handler){
        socket_.async_read_some(recv_buf, handler);
    }


    /*
    *   shutdown
    */
    void shutdown(){
        if(is_open()){
            boost::system::error_code ec;
            socket_.shutdown(boost::asio::ip::tcp::socket::shutdown_both, ec);
            if(ec){
                // may print shutdown error
            }
            socket_.close();
        }
    }

    /*
    *   socket
    *       : returning the current holding socket
    */
    boost::asio::ip::tcp::socket& socket(){
        return socket_;
    }
};

typedef boost::shared_ptr<ws_async_tcp_connection> async_tcp_ptr;


-------------------------------------------------------------------------------
src
-------------------------------------------------------------------------------

class async_tcp_test_server{
    enum{ buf_size = 1024 };
    boost::asio::ip::tcp::acceptor acceptor_;
    boost::array<char, buf_size> send_buf;
    boost::array<char, buf_size> recv_buf;
public:
    async_tcp_test_server(boost::asio::io_service& io_service, unsigned short port_no)
        : acceptor_(io_service, boost::asio::ip::tcp::endpoint(boost::asio::ip::tcp::v4(), port_no)){

        // start an accept operation for a new connection
        async_tcp_ptr new_conn(new ws_async_tcp_connection(acceptor_.get_io_service()));
        acceptor_.async_accept(new_conn->socket(), boost::bind(&async_tcp_test_server::handle_accept, this,
            boost::asio::placeholders::error, new_conn));
    }

    void handle_accept(const boost::system::error_code& ec, async_tcp_ptr conn){

        if(!ec){
            send_buf.assign(0x00);
            string hello_str = "Welcome to connect Asynchronous TCP Test Server :)";
            memcpy(&send_buf[0], hello_str.c_str(), hello_str.length());
            conn->async_send_msg(boost::asio::buffer(send_buf), boost::bind(&async_tcp_test_server::handle_write, this, boost::asio::placeholders::error, conn));
            //conn->async_send_msg_some(boost::asio::buffer(send_buf), boost::bind(&async_tcp_test_server::handle_write, this, boost::asio::placeholders::error, 
                //boost::asio::placeholders::bytes_transferred, conn));
        }

        // start an accept operation for new connection
        async_tcp_ptr new_conn(new ws_async_tcp_connection(acceptor_.get_io_service()));
        acceptor_.async_accept(new_conn->socket(), boost::bind(&async_tcp_test_server::handle_accept, this,
            boost::asio::placeholders::error, new_conn));
    }


    void handle_write(const boost::system::error_code& ec, async_tcp_ptr conn){
        if(!ec){
            recv_buf.assign(0x00);
            conn->async_recv_msg_some(boost::asio::buffer(recv_buf), boost::bind(&async_tcp_test_server::handle_read, this, boost::asio::placeholders::error, 
                boost::asio::placeholders::bytes_transferred));
        }
    }


    void handle_read(const boost::system::error_code& ec, size_t num_recv_bytes){
        cout << recv_buf.data() << endl;
    }
};


int main(void)
{
    unsigned short port_no = 7807;
    boost::asio::io_service io_svr;
    async_tcp_test_server test_server(io_svr, port_no);
    io_svr.run();
}

以下是错误输出（在我改变T＆amp; - ＆gt; const T＆amp;之后）

/home/chris/proto/boost/boost/bind/bind_template.hpp:15：从＆＃39; boost :: _ bi :: bind_t，boost :: arg＆lt; 1＆gt;实例化（）（），boost :: arg＆lt; 2＆gt; （）（），boost :: _ bi :: value＆gt; ＆GT; ＆GT;＆＃39; async_tcp_test_server.cpp：46：从这里实例化 /home/chris/proto/boost/boost/bind/bind.hpp:69：错误：＆＃39; void（async_tcp_test_server :: *）（const boost :: system :: error_code＆amp;，size_t）＆＃39;不是类，结构或联合类型 /home/chris/proto/boost/boost/asio/basic_stream_socket.hpp：在成员函数＆＃39; void boost :: asio :: basic_stream_socket :: async_read_some（const MutableBufferSequence＆amp;，const ReadHandler＆amp;）[with MutableBufferSequence = boost：：asio :: mutable_buffers_1，ReadHandler = boost :: _ bi :: bind_t，boost :: arg＆lt; 1＆gt; （）（），boost :: arg＆lt; 2＆gt; （）（），boost :: _ bi :: value＆gt; ＆GT; ＆gt;，Protocol = boost :: asio :: ip :: tcp，StreamSocketService = boost :: asio :: stream_socket_service]＆＃39;： /home/chris/proto/inc/ws_async_tcp_connection.h:120：从＆＃39; void ws_async_tcp_connection :: async_recv_msg_some（const T＆amp;，Handler）实例化[使用T = boost :: asio :: mutable_buffers_1，Handler = boost :: _bi :: bind_t，boost :: arg＆lt; 1＆gt; （）（），boost :: arg＆lt; 2＆gt; （）（），boost :: _ bi :: value＆gt; ＆GT; ＆GT;]＆＃39; async_tcp_test_server.cpp：46：从这里实例化 /home/chris/proto/boost/boost/asio/basic_stream_socket.hpp:785：错误：无法调用＆＃39;（boost :: _ bi :: bind_t，boost :: arg＆lt; 1＆gt;（ ）（），boost :: arg＆lt; 2＆gt;（）（），boost :: _ bi :: value＆gt;＆gt;＆gt;）（const boost :: system :: error_code＆amp;，const long unsigned int＆amp; ）＆＃39; /home/chris/proto/boost/boost/asio/detail/bind_handler.hpp：在成员函数＆＃39; void boost :: asio :: detail :: binder2 :: operator（）（）[with Handler = boost：：_bi :: bind_t，boost :: arg＆lt; 1＆gt; （）（），boost :: arg＆lt; 2＆gt; （）（），boost :: _ bi :: value＆gt; ＆GT; ＆gt;，Arg1 = boost :: system :: error_code，Arg2 = long unsigned int]＆＃39;： /home/chris/proto/boost/boost/asio/handler_invoke_hook.hpp:64：从＆lt; void boost :: asio :: asio_handler_invoke（函数，...）实例化[与Function = boost :: asio :: detail :: binder2，boost :: arg＆lt; 1＆gt; （）（），boost :: arg＆lt; 2＆gt; （）（），boost :: _ bi :: value＆gt; ＆GT; ＆gt;，boost :: system :: error_code，long unsigned int＆gt;]＆＃39; /home/chris/proto/boost/boost/asio/detail/handler_invoke_helpers.hpp:39：从＆lt; void boost_asio_handler_invoke_helpers :: invoke（函数＆amp;上下文＆amp;）实例化[与Function = boost :: asio :: detail :: binder2，boost :: arg＆lt; 1＆gt; （）（），boost :: arg＆lt; 2＆gt; （）（），boost :: _ bi :: value＆gt; ＆GT; ＆gt;，boost :: system :: error_code，long unsigned int＆gt;，Context = boost :: _ bi :: bind_t，boost :: arg＆lt; 1＆gt; （）（），boost :: arg＆lt; 2＆gt; （）（），boost :: _ bi :: value＆gt; ＆GT; ＆GT;]＆＃39; /home/chris/proto/boost/boost/asio/detail/reactive_socket_recv_op.hpp:110：实例化为＆＃39; static void boost :: asio :: detail :: reactive_socket_recv_op :: do_complete（boost :: asio :: detail :: io_service_impl *，boost :: asio :: detail :: operation *，const boost :: system :: error_code＆amp;，size_t）[with MutableBufferSequence = boost :: asio :: mutable_buffers_1，Handler = boost :: _ bi :: bind_t ，boost :: arg＆lt; 1＆gt; （）（），boost :: arg＆lt; 2＆gt; （）（），boost :: _ bi :: value＆gt; ＆GT; ＆GT;]＆＃39; /home/chris/proto/boost/boost/asio/detail/reactive_socket_recv_op.hpp:80：从＆＃39; boost :: asio :: detail :: reactive_socket_recv_op :: reactive_socket_recv_op实例化（boost :: asio :: detail :: socket_type，boost :: asio :: detail :: socket_ops :: state_type，const MutableBufferSequence＆amp;，int，Handler＆amp;）[with MutableBufferSequence = boost :: asio :: mutable_buffers_1，Handler = boost :: _ bi :: bind_t，boost :: ARG＆LT 1为卤素; （）（），boost :: arg＆lt; 2＆gt; （）（），boost :: _ bi :: value＆gt; ＆GT; ＆GT;]＆＃39; /home/chris/proto/boost/boost/asio/detail/reactive_socket_service_base.hpp:273：从＆lt; void boost :: asio :: detail :: reactive_socket_service_base :: async_receive实例化（boost :: asio :: detail：：reactive_socket_service_base :: base_implementation_type＆amp;，const MutableBufferSequence＆amp;，int，Handler）[with MutableBufferSequence = boost :: asio :: mutable_buffers_1，Handler = boost :: _ bi :: bind_t，boost :: arg＆lt; 1＆gt; （）（），boost :: arg＆lt; 2＆gt; （）（），boost :: _ bi :: value＆gt; ＆GT; ＆GT;]＆＃39; /home/chris/proto/boost/boost/asio/stream_socket_service.hpp:318：从＆lt; void boost :: asio :: stream_socket_service :: async_receive实例化（typename boost :: asio :: detail :: reactive_socket_service :: implementation_type＆amp;，const MutableBufferSequence＆amp;，int，const ReadHandler＆amp;）[with MutableBufferSequence = boost :: asio :: mutable_buffers_1，ReadHandler = boost :: _ bi :: bind_t，boost :: arg＆lt; 1＆gt; （）（），boost :: arg＆lt; 2＆gt; （）（），boost :: _ bi :: value＆gt; ＆GT; ＆gt;，Protocol = boost :: asio :: ip :: tcp]＆＃39; /home/chris/proto/boost/boost/asio/basic_stream_socket.hpp:787：从＆lt; void boost :: asio :: basic_stream_socket :: async_read_some（const MutableBufferSequence＆amp;，const ReadHandler＆amp;）实例化[与MutableBufferSequence = boost :: asio :: mutable_buffers_1，ReadHandler = boost :: _ bi :: bind_t，boost :: arg＆lt; 1＆gt; （）（），boost :: arg＆lt; 2＆gt; （）（），boost :: _ bi :: value＆gt; ＆GT; ＆gt;，Protocol = boost :: asio :: ip :: tcp，StreamSocketService = boost :: asio :: stream_socket_service]＆＃39; /home/chris/proto/inc/ws_async_tcp_connection.h:120：从＆＃39; void ws_async_tcp_connection :: async_recv_msg_some（const T＆amp;，Handler）实例化[使用T = boost :: asio :: mutable_buffers_1，Handler = boost :: _bi :: bind_t，boost :: arg＆lt; 1＆gt; （）（），boost :: arg＆lt; 2＆gt; （）（），boost :: _ bi :: value＆gt; ＆GT; ＆GT;]＆＃39; async_tcp_test_server.cpp：46：从这里实例化 /home/chris/proto/boost/boost/asio/detail/bind_handler.hpp:118：错误：调用＆＃39;（boost :: _ bi :: bind_t，boost :: arg＆lt; 1＆gt;（< em>）（），boost :: arg＆lt; 2＆gt;（）（），boost :: _ bi :: value

Answer 1

正如编译器所说，您正在调用的函数需要对缓冲区的非const引用： async_recv_msg_some(T&, ... [with T = boost::asio::mutable_buffers_1

您按值传递缓冲区：async_recv_msg_some(boost::asio::mutable_buffers_1,因为您将其创建为具有右值表达式boost::asio::buffer(recv_buf)的临时对象。

您必须更改功能签名才能采用T或const T&（我会选择const T&，因为这是async_read_some所采用的功能，以及您的功能只是转发到那个）

Boost.asio async_read_some编译错误

1 个答案: