I think what's unexpected is that (0..10).map(|x| x * x) doesn't implement Copy. I think that's something that could be implemented as Copy closures are a thing

I think what's unexpected is that (0..10).map(|x| x * x) doesn't implement Copy. I think that's something that could be implemented as Copy closures are a thing now (or maybe soon). Although wait, the problem is more that (0..10) itself isn't Copy, now that I think about it.