TreeSet
, that rely on natural ordering,
whose element type doesn't implement the Comparable
interface.
It's unlikely that such a collection will work properly.
A false positive is possible if the collection element type is a non-comparable super-type,
but the collection is intended to only hold comparable sub-types. Even if this is the case,
it's better to narrow the collection element type or declare the super-type as Comparable
because the mentioned approach is error-prone.
The inspection also reports cases when the collection element is a type parameter which is not declared as extends Comparable
.
You can suppress the warnings on type parameters using the provided option (for example, to keep the API compatibility).
New in 2018.3