How to remove an element of a vector inside a loop?

Question

C++ / C#

Hello gentlemen comrades! There is a vector of pointers to class objects. Loop through all the elements of the given vector. It is necessary, when a certain condition is met, to remove an element inside the loop. How to do it?

Answer 1

You can do everything without a loop:

contours.erase(std::remove_if(contours.begin(), contours.end(),
    [this](std::vector<cv::Point> vec)->bool
                         {return vec.size() < this->mParams.minContourSize; })
    ,contours.end());

Answer 2

Iterate from the end, after which, to delete, you can move the tail element to the place of the one being deleted and reduce the length of the vector by 1 (in metadata, that is, if you have a class with a vector, you reduce the field indicating the number of significant elements in the vector). Otherwise, only by copying the region, because C does not know how to make arrays of variable length, the programmer needs to take care of this.