Question

我正在尝试为我的OpenCV应用程序创建一个线程抓取器。我无法弄清楚为什么这段代码不能编译。它给了我一个错误，我认为这意味着函数调用是错误的。但是，它通常与使用std :: thread启动线程的方式完全相同！我想使用std :: thread来完成它，因为它将提供更多与平台无关的兼容性，所以请不要告诉我使用特定于平台的库。我也希望这是基于STL的，所以没有Boost或DLib。在我的main.cpp中，我有一个工作线程应用程序，代码如下：

#include <iostream>
#include <fstream>
#include <string>
#include <thread>
#include <mutex>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/objdetect/objdetect.hpp>
#include <opencv2/imgproc/imgproc.hpp>

#define read_failure_threshold 512
long grabbers_active = 0;

namespace dev
{
        class grabber
        {
        private:
        bool enabled = false;
        std::mutex lock;
        int capture_mode;
        int capture_id;
        unsigned long read_failures = 0;
        std::string stream;
        std::string grabber_name;
        cv::Mat image;
    public:
        void grabber_t()
        {
            .......[unimportant code]........
        }

        grabber(std::string name, int captureMode, int captureId, std::string location)
        {
            .......[unimportant code]........
        }

        void start()
        {
            if(!enabled)
            {
               std::thread grabber_thread(grabber_t);
               grabber_thread.detach();
            }
            enabled = true;
            grabbers_active++;
        }

        cv::Mat getImage()
        {
            .......[unimportant code]........
        }
    };
}


[ERRORS:]
In file included from /media/storage/programming/yash101/repos/Other/STL+OpenCV/threaded_grabber_template/main.cpp:1:0:
/media/storage/programming/yash101/repos/Other/STL+OpenCV/threaded_grabber_template/template.hpp: In member function ‘void dev::grabber::start()’:
/media/storage/programming/yash101/repos/Other/STL+OpenCV/threaded_grabber_template/template.hpp:119:52: error: no matching function for call to ‘std::thread::thread(<unresolved overloaded function type>)’
                std::thread grabber_thread(grabber_t);
                                                    ^
/media/storage/programming/yash101/repos/Other/STL+OpenCV/threaded_grabber_template/template.hpp:119:52: note: candidates are:
In file included from /media/storage/programming/yash101/repos/Other/STL+OpenCV/threaded_grabber_template/template.hpp:4:0,
                 from /media/storage/programming/yash101/repos/Other/STL+OpenCV/threaded_grabber_template/main.cpp:1:
/usr/include/c++/4.8/thread:133:7: note: std::thread::thread(_Callable&&, _Args&& ...) [with _Callable = void (dev::grabber::*)(); _Args = {}]
       thread(_Callable&& __f, _Args&&... __args)
       ^
/usr/include/c++/4.8/thread:133:7: note:   no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘void (dev::grabber::*&&)()’
/usr/include/c++/4.8/thread:128:5: note: std::thread::thread(std::thread&&)
     thread(thread&& __t) noexcept
     ^
/usr/include/c++/4.8/thread:128:5: note:   no known conversion for argument 1 from ‘<unresolved overloaded function type>’ to ‘std::thread&&’
/usr/include/c++/4.8/thread:122:5: note: std::thread::thread()
     thread() noexcept = default;
     ^
/usr/include/c++/4.8/thread:122:5: note:   candidate expects 0 arguments, 1 provided
make[2]: *** [CMakeFiles/build.dir/main.cpp.o] Error 1
make[1]: *** [CMakeFiles/build.dir/all] Error 2
make: *** [all] Error 2

错误日志也在代码的末尾。我担心的唯一错误是线程错误。其他的是简单的修复，但要求我让线程工作。我在Ubuntu，使用g ++（Ubuntu 4.8.2-19ubuntu1）4.8.2。我的CMakeLists.txt中启用了C ++ 0x。一切都在那里完美运作

我的主要目标是找出我收到此错误的原因。我一直在谷歌搜索和尝试不同的技巧，但没有任何工作！

先谢谢您的帮助：）

Answer 1

改变：

std::thread grabber_thread(grabber_t);

进入那个：

std::thread grabber_thread(&grabber::grabber_t, this);

grabber_t是对非静态成员函数的引用，需要传递其地址，但是&grabber_t不能正常工作，因为在获取其地址时必须明确限定成员函数的名称，因此结果为&grabber::grabber_t。

C ++ 11线程没有匹配的函数调用

1 个答案: