I can do this via fold: let count = input .iter() .fold(0, |acc, item| if predicate(&item) { acc + 1 } else { acc }); However, I feel like this is a fairly common goal and I might be overcomplicating it. Is there something in the stdlib that allows doing the above with an interface that …

Is there a shorthand for counting items in an iterator that satisfy a predicate?

bjorn3 December 19, 2020, 5:04pm 2

I think input.iter().filter(predicate).count() will work.

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