interface Ordered
pub interface Ordered :: [Equatable]Conforms to Equatable.
The operators <, <=, > and >=, which read a.compare(b).
.Less means <; null means the two are not ordered (float is partial, NaN compares
with nothing), in which case every one of the four is false.
Methods
fn compare(o: Self): ?OrderingCompares this with o; null where the two are not ordered.
Synthesized lexicographically over the fields: the first that is not .Equal decides,
and an unordered field (null) is the answer; an enum by the variant's position first,
then its payload.