C++/Boost:将成员函数作为参数传递给 boost::bind

Question

我是 C++ 的新手，所以请不要评判我:-)

我有一个名为 connection 的类，它包含以下方法:

    void connection::handle_connect(const boost::system::error_code& err) {
        if (!err) {
            boost::asio::async_write(socket_, request_,
                boost::bind(&connection::handle_write_request, this,
                boost::asio::placeholders::error, &connection::handle_read_status_line));
        } else {
            std::cout << "Error in handle_connect: " << err.message() << "\n";
        }
    }

    void connection::handle_write_request(const boost::system::error_code& err, boost::function<void(const boost::system::error_code&)> callback) {
        if (!err) {
            boost::asio::async_read_until(socket_, response_, 0,
                boost::bind(&callback, this,
                boost::asio::placeholders::error));
        } else {
            std::cout << "Error in handle_write_request: " << err.message() << "\n";
        }
    }

    void connection::handle_read_status_line(const boost::system::error_code& err) {
        if (!err) {
            std::istream response_stream(&response_);
            std::string response;
            std::getline(response_stream, response);
            std::cout << "Response: " << response << std::endl;
        } else {
            std::cout << "Error in handle_read_status_line: " << err << "\n";
        }
    }

我正在尝试使 handle_write_request 方法更加通用。我已经在其签名中添加了 callback - 这应该是传递给 boost::bind 并在 boost 中作为回调调用的方法的地址: :asio::async_read_until.

但是，这甚至无法编译 :-) MSVS2013 说

    Error   1   error C2825: 'F': must be a class or namespace when followed by '::'    C:\local\boost_1_55_0\boost\bind\bind.hpp   69  1   driver
    Error   2   error C2039: 'result_type' : is not a member of '`global namespace''    C:\local\boost_1_55_0\boost\bind\bind.hpp   69  1   driver
    Error   3   error C2146: syntax error : missing ';' before identifier 'type'    C:\local\boost_1_55_0\boost\bind\bind.hpp   69  1   driver
    Error   4   error C2208: 'boost::_bi::type' : no members defined using this type C:\local\boost_1_55_0\boost\bind\bind.hpp  69  1   driver
    Error   5   error C1903: unable to recover from previous error(s); stopping compilation C:\local\boost_1_55_0\boost\bind\bind.hpp   69  1   driver

如何正确传递成员函数的地址？如果有任何建议，我将不胜感激!

Answer 1

要绑定(bind)类的成员函数，请执行以下操作:

boost::bind(&SomeClass::SomeMemberFunc, this, params...);

在你的例子中，callback已经是一个仿函数，所以尝试 boost::bind(callback, this, <some proper parameter>);