generics - Why Java PriorityQueue does not enforce a Comparable Object -

generics - Why Java PriorityQueue<T> does not enforce a Comparable Object -

why priorityqueue in java defined as,

priorityqueue<t>

and not as,

priorityqueue<t extends comparable<? super t>

it rather gives classcastexception @ runtime if not queue objects of type comparable. (and if not using custom comparator).

why not grab @ compile time?

it's done can still utilize priority queue objects not implement comparable interface. in such cases supply own custom comparator , works.

this increases usability of class, @ minimal no cost. behavior well-documented in javadoc.

java generics collections priority-queue