> I cringe at every loop wondering what the performance cost will be (it's not always clear or predictable). Really? I think it's fairly easy to determine what

> I cringe at every loop wondering what the performance cost will be (it's not always clear or predictable). Really? I think it's fairly easy to determine what would be expensive vs. what's going to be relatively cheap. I'd love a counterintuitive example to prove me wrong though.