A quick glance at the implementors of
shows that most collections implement it. From discussion on IRC I’ve been told that most of these orderings are probably “lexicographical ordering of all elements in sorted order”, which is not the expected ordering (set inclusion) for most collections. In particular for the -
Set types this is wrong.
Ord is required to use these types as keys in many collections. This also seems wrong to me. Why isn’t
PartialOrd sufficient for keying?
Should these implementations be dropped?