Java PriorityQueue(PriorityQueue) constructor

Is the java API PriorityQueue constructor that takes another priority queue destructive to the argument?开发者_运维问答 If so, is its clone() method adequate for creating a shallow copy?

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No, it is not destructive. Pretty much all the collection classes have copy constructors, and are non-destructive by convention.

The reason there are overloaded constructors is for efficiency; when a PQ or SortedSet is supplied, one can imagine that the initial population of elements can be O(n) instead of O(n log n)