How to pass MyClass[][] for MyClass**?

Question

Why can't I pass

    Point src[1][4] = {
        {
            Point(border,border), Point(border,h-border), Point(w-border,h-border), Point(w-border,h-border)
        }
    };

as

polylines(frame, src, ns, 1, true, CV_RGB(255,255,255), 2); 

where

polylines has prototype

void polylines(Mat& img, const Point** pts, const int* npts, int ncontours, bool isClosed, const Scalar& color, int thickness=1, int lineType=8, int shift=0 )

UPDATE

Okay, okay, I remembered this stuff :)

Answer 1

Point[1][4] can't be converted to Point** this way.
Have a look at this question: Converting multidimensional arrays to pointers in c++

The actual solution here is to use STL container instead of C-style array, e.g. std::vector:

typedef std::vector<Point> Shape;
std::vector<Shape> myShapes;
...

and pass it by const reference instead of const pointer:

void polylines(Mat& img, const std::vector<Shape>& shapes, ...)

Also note that src, ns, pts, etc. aren't very lucky names for your variables. Try to choose more meaningful names... if not for your own sake, then do it for the sake of future readers of that code :)