CvQueryFrame not returning cv :: Mat?

I have an old project where I did something like this:

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>

(...)

CvCapture* capture;
cv::Mat frame;

capture = cvCaptureFromCAM(0);
frame = cvQueryFrame(capture);

(...)

      

        
        
        
      

    

And it worked.

Now I created a new project and now I have an error:

error C2440: '=': cannot convert from 'IplImage *' to 'cv :: Mat *'

The only difference between these projects that I notice is that the new one is written in CLR C ++. Both are using openCV 2.4.11.

Why was cvQueryFrame () in my old project able to return cv :: Mat and a new one? What did I miss?