> After inspecting the code I made a fix. For open polygons, copying the very last segment, it did not work correctly and therefore failed. This was because the size of the range was inspected before the view. Most probably this was the problem. That was after 1.57 was released, so you don't have it. It's this commit:
>
> https://github.com/boostorg/geometry/commit/16fb68921763ca188397d5e1bebf6ff005ecdaa8
>
> In fact I implemented your suggestion too, because it asserts now and always return true. We can remove its return value now (I think I will do).

That’s cool! J You made my day. Thank you so much!

Have a nice rest of the weekend

   Volker