What design pattern is best suitable with this context?

Question

I have a base class Shape, and drived classes Line Segment, Arc, B-spline,... I want to find the intersection point between these shapes. I would like:

Shape* a = new LineSegment();
Shape* b = new Arc();

bool did_intersect = a->Intersect(b);

I don't like this design in Intersect:

bool LineSegment(Shape* s) {
  Arc* arc = dynamic_cast<Arc*>(s);
  if (NULL != arc)
    return LineSegmentArcIntersection(this, arc);

  BSpline* bspline = dynamic_cast<BSpline*>(s);
  if (NULL != bspline)
    return LineSegmentBSplineIntersection(this, bspline);
  ...
}

So, What design pattern is best suitable with this context?

Answer 1

I think you are looking for double dispatch or multiple dispatch.

Btw., this question is better suited for StackOverflow.