[c++] Return a class safely

Passing cv::Mat by reference or return it?

If copy elision gets applied, the 2nd case would be more efficient.

void myimread (cv::Mat &mat, const std::string &imgname){
  mat = imread(imgname);
}

cv::Mat myimread (const std::string &imgname){
  return imread(imgname);
}

 

什么是copy elision

C++编译器优化：Copy Elision（省略不必要的拷贝）