Semantics of the evaluation of iterator arguments

[rbehrends]

There is a potential issue with how iterator arguments are evaluated. See my Stackoverflow post here for the gritty details.

I also note that in addition to what I observed, sometimes inline iterators also seem to evaluate their arguments multiple times (e.g. if you make the take iterator in the code inline, it still doesn't work).

My recommendation would be to settle on once-per-iteration or once-per-loop evaluation as a default for both inline and closure iterators and to have a pragma to allow for the other behavior as an option.

[stale]

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