I have so far transformed two crates that have iterable-like properties in traits from using HRTBs to GATs. And I was seriously surprised how easy it was. The compiler gave me all the hints I needed to make everything compile. And there were only minor changes required, like removing lifetime arguments from traits or changing the type definition in trait implementations.

I wonder, has anyone encountered any difficulties when transforming their code from HRTBs to GATs?