It is a surprise. I have seen and written buggy comparators that violated strict weak ordering (these usually involve floating points...). But I have never seen

It is a surprise. I have seen and written buggy comparators that violated strict weak ordering (these usually involve floating points...). But I have never seen mutating or throwing comparators. It is great that rust can prevent them those additional issues, but in the grand scheme of things it is not something I lose sleep about.