Howto call an unmanaged C++ function with a std::vector as parameter from C#?

Question

I have a C# front end and a C++ backend for performance reasons. Now I would like to call a C++ function like for example:

void findNeighbors(Point p, std::v         


        

Answer 1

The best solution here is to write a wrapper function in C which is limited to non-C++ classes. Non-trivial C++ classes are essentially unmarshable via the PInvoke layer [1]. Instead have the wrapper function use a more traditional C signature which is easy to PInvoke against

void findNeigborsWrapper(
  Point p,
  double maxDist, 
  Point** ppNeighbors,
  size_t* pNeighborsLength)

[1] Yes there are certain cases where you can get away with it but that's the exception and not the rule.