boost ASIO async_read_until不能用ASIO ssl客户端编译示例

Question

从this example开始，我想用async_read_until()替换async_read()。

所以我抬头看了this example，看到async_read_until()被调用。我看到它被称为如下：

 boost::asio::async_read_until(socket_, response_, "\r\n", 
     boost::bind(&client::handle_read_status_line, this, 
     boost::asio::placeholders::error)); 

因此，我认为相比于SSL客户端的例子，唯一的区别是，response_是boost::asio::streambuf。所以，我创建了一个对象在我的类主体以同样的方式，然后在SSL客户端的例子，我代替回调函数：

boost::asio::async_read(socket_, 
     boost::asio::buffer(reply_, bytes_transferred), 
     boost::bind(&SSLClient::handle_read, this, 
     boost::asio::placeholders::error, 
     boost::asio::placeholders::bytes_transferred)); 

与其他功能，并删除了bytes_transferred部分。它变成：

boost::asio::async_read_until(socket_, response_, "\r\n", 
     boost::bind(&SSLClient::handle_read, this, 
     boost::asio::placeholders::error)); 

但是...这不会编译。它给了我这些错误：

In file included from /usr/include/boost/bind.hpp:22:0, 
       from SSLClient.h:5, 
       from main.cpp:14: 
/usr/include/boost/bind/bind.hpp: In instantiation of 'struct boost::_bi::result_traits<boost::_bi::unspecified, void (SSLClient::*)(const boost::system::error_code&, long unsigned int)>': 
/usr/include/boost/bind/bind_template.hpp:15:48: required from 'class boost::_bi::bind_t<boost::_bi::unspecified, void (SSLClient::*)(const boost::system::error_code&, long unsigned int), boost::_bi::list2<boost::_bi::value<SSLClient*>, boost::arg<1> (*)()> >' 
SSLClient.h:99:51: required from here 
/usr/include/boost/bind/bind.hpp:69:37: error: 'void (SSLClient::*)(const boost::system::error_code&, long unsigned int)' is not a class, struct, or union type 
    typedef typename F::result_type type; 
            ^
In file included from main.cpp:14:0: 
SSLClient.h:87:70: warning: unused parameter 'bytes_transferred' [-Wunused-parameter] 
    void handle_write(const boost::system::error_code& error, size_t bytes_transferred) 
                    ^
In file included from /usr/include/boost/asio/impl/io_service.hpp:18:0, 
       from /usr/include/boost/asio/io_service.hpp:767, 
       from /usr/include/boost/asio/basic_io_object.hpp:19, 
       from /usr/include/boost/asio/basic_socket.hpp:20, 
       from /usr/include/boost/asio/basic_datagram_socket.hpp:20, 
       from /usr/include/boost/asio.hpp:21, 
       from SSLClient.h:6, 
       from main.cpp:14: 
/usr/include/boost/asio/impl/read_until.hpp: In instantiation of 'typename boost::asio::async_result<typename boost::asio::handler_type<WriteHandler, void(boost::system::error_code, long unsigned int)>::type>::type boost::asio::async_read_until(AsyncReadStream&, boost::asio::basic_streambuf<Allocator>&, const string&, ReadHandler&&) [with AsyncReadStream = boost::asio::ssl::stream<boost::asio::basic_stream_socket<boost::asio::ip::tcp> >; Allocator = std::allocator<char>; ReadHandler = boost::_bi::bind_t<boost::_bi::unspecified, void (SSLClient::*)(const boost::system::error_code&, long unsigned int), boost::_bi::list2<boost::_bi::value<SSLClient*>, boost::arg<1> (*)()> >; typename boost::asio::async_result<typename boost::asio::handler_type<WriteHandler, void(boost::system::error_code, long unsigned int)>::type>::type = void; std::string = std::basic_string<char>]': 
SSLClient.h:99:52: required from here 
/usr/include/boost/asio/impl/read_until.hpp:707:3: error: static assertion failed: ReadHandler type requirements not met 
    BOOST_ASIO_READ_HANDLER_CHECK(ReadHandler, handler) type_check; 
^
/usr/include/boost/asio/impl/write.hpp:615:3: error: no match for call to '(boost::_bi::bind_t<boost::_bi::unspecified, void (SSLClient::*)(const boost::system::error_code&, long unsigned int), boost::_bi::list2<boost::_bi::value<SSLClient*>, boost::arg<1> (*)()> >) (const boost::system::error_code&, const long unsigned int&)' 
    BOOST_ASIO_WRITE_HANDLER_CHECK(WriteHandler, handler) type_check; 
^
Makefile:472: recipe for target 'main.o' failed 
make: *** [main.o] Error 1 
13:14:05: The process "/usr/bin/make" exited with code 2. 
Error while building/deploying project GNOMEClientCmd (kit: Qt 5.4.1) 
When executing step "Make" 
13:14:05: Elapsed time: 00:04. 

我不得不这样做，以获得所有这些错误，也同样说明切换从async_read到async_read_until。如果我回到async_read，它编译得很好。我究竟做错了什么？

如果您需要任何其他信息，请询问。谢谢。

Answer 1

问：我做错了

你忽略的文档。

该文档会告诉您，async_read-until需要一个streambuf¹，并且ReadHandler需要仍然使用bytes_transferred占位符。

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¹只是注意到你描述了在散文中;它显示相关的代码很好。首选SSCCE SO