True! I didn't even remember that detail. To respond to that comment nearly a decade later, I might object that swapping a zero copy zero allocations iterator for something that does O(N^2) element copies and allocates N new lists for zero practical benefit cannot be beautiful on principle, regardless of how pretty it looks on the surface.

Beauty is when practicality and perception pull in parallel towards purpose. Sacrificing one for the other can have a certain aesthetic quality, but I would not call it beautiful.