c++ - Weird crash when I try to attribute a variable in OpenCV IOS -

there i'm not able understand. i'm using opencv ios ios device.

i have c++ class private variable cv::rect . variable located .h file. in .cpp file, have method creates cv::rect. then, attribute new created cv::rect class variable crashs , not understand why.

.h file

class detection {   public:     detection();      cv::mat processimage(cv::mat frame);      cv::mat detectface(cv::mat frame);  public:     cv::rect getrectangledetection();     void setrectangledetection(cv::rect& rect);   private:     cv::rect _rectangedetect;  }; 

.cpp file

    cv::mat detection::processimage(cv::mat frame){      mat originalcolorimage;     frame.copyto(originalcolorimage);     int cx = frame.cols/2;     int cy = frame.rows/2;     int width = 1000;     int height = 1000;     nslog(@"[info] rectangle creation");      cv::rect rect1(cx-width/2,  cy-height/2, width,height);      cv::rect test2;     //test2 = rect1;//it works !      setrectangledetection(rect1); // or _rectangedetect = rect1 --> both don't work      cv::rectangle( originalcolorimage,rect1,                   cv::scalar(255, 0, 0),4);        return originalcolorimage; } 

i took @ crash report , saw :

exception type:  exc_bad_access (sigsegv) exception subtype: kern_invalid_address @ 0x0000000000000000 triggered thread:  0  filtered syslog: none found  thread 0 name:  dispatch queue: com.apple.main-thread thread 0 crashed: 0   detect          0x000000010007f580 cv::rect_<int>::operator=(cv::rect_<int> const&) (types.hpp:1689) 1   detect          0x000000010007f504 opencv::setrectangledetection(cv::rect_<int>) (opencv.mm:172) //this setter if i'm not using setter error come _rectangledetect = rect1. 

i tried initialize variable cv::rect same behavior.

do have idea what's happen ? really, tried figure out why without success. used lot opencv before , it's first time happens.

thank !

okey found problem. silly one. actually, on other class when using detection class, forgot initialize object.

detection _detect = new detection() 

as did not error following line , fact behavior seemed (even debug), did not think of that.

_detect->processimage(frame); 

thank guys anyway.