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Using Enumeration when performing remove operations on a vector may cause unexpected program behavior.
The Coverity Prevent Version 5.0 ITERATOR checker can detect the instance where next() or previous() on an iterator is called that may not have a next or previous element.
Bibliography
[API 2011] Interfaces Enumeration<E> and Iterator<E>
[Daconta 2003] Item 21: Use Iteration over Enumeration
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