As you might have guessed from the title, this is similar to the Trusted Iterator Length Problem, but with the PartialEq, Eq, PartialOrd, and Ord traits instead.
I have created an RFC for Unsafe comparison traits, but it has been pretty controversial.
There are various disagreements on various details (currently with 54 comments, 7 unresolved questions, 4 alternatives, and 5 drawbacks). Therefore, I am asking for more opinions and ideas here. However, please add comments on the linked RFC, and not here.