It being something this fundamental, it's almost inevitable that some application out there is meaningfully impacted by this difference. Maybe not yours - and i

It being something this fundamental, it's almost inevitable that some application out there is meaningfully impacted by this difference. Maybe not yours - and indeed, I wouldn't step down into the int version without a benchmark showing that it's a problem in my specific case - but it's not hard to imagine cases where this would have a huge impact. But even setting that aside: I think the author's point was less that you should never use EnumSet, and more that the very fact that it exists is an illustration of the flaws at the language's core.