additional iterator traits for Take + Repeat/RepeatWith
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The `iter::repeat()` and `iter::repeat_with()` docs recommend combining them with `take()` to
get finite iterators. Currently those combinations don't implement ExactSizeIterator
or DoubleEndedIterator. This adds them where appropriate
```diff
+ impl<T: Clone> DoubleEndedIterator for Take<Repeat<T>>
+ impl<T, F> ExactSizeIterator for Take<RepeatWith<F>> where F: FnMut() -> T {}
+ impl<T: Clone> ExactSizeIterator for Take<Repeat<T>> {}
```
`DoubleEndedIterator` is not implemented for `Take<RepeatWith>` because the
generating closure may be stateful and can only dispense items in the
forward direction.
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r? @scottmcm (rustbot has picked a reviewer for you, use r? to override) |
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r? libs-api |
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☔ The latest upstream changes (presumably #115273) made this pull request unmergeable. Please resolve the merge conflicts. |
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Similar one #106943 |
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Thanks, I missed that one. The main difference is the |
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closing in favor of #106943 |
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The
iter::repeat()anditer::repeat_with()docs recommend combining them withtake()to get finite iterators. Currently those combinations don't implement ExactSizeIterator or DoubleEndedIterator. This adds them where appropriateDoubleEndedIteratoris not implemented forTake<RepeatWith>because the generating closure may be stateful and can only dispense items in the forward direction.These changes are insta-stable.