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array_chunks: remove Option wrapper from into_remainder's return type #148249

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hkBst wants to merge 1 commit into from
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array_chunks: remove Option wrapper from into_remainder's return type #148249

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10 changes: 5 additions & 5 deletions library/core/src/iter/adapters/array_chunks.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -40,17 +40,17 @@ where
/// # // Also serves as a regression test for https://github.com/rust-lang/rust/issues/123333
/// # #![feature(iter_array_chunks)]
/// let x = [1,2,3,4,5].into_iter().array_chunks::<2>();
/// let mut rem = x.into_remainder().unwrap();
/// let mut rem = x.into_remainder();
/// assert_eq!(rem.next(), Some(5));
/// assert_eq!(rem.next(), None);
/// ```
#[unstable(feature = "iter_array_chunks", reason = "recently added", issue = "100450")]
#[inline]
pub fn into_remainder(mut self) -> Option<array::IntoIter<I::Item, N>> {
if self.remainder.is_none() {
while let Some(_) = self.next() {}
pub fn into_remainder(mut self) -> array::IntoIter<I::Item, N> {
while self.remainder.is_none() {
let _ = self.next();
}
self.remainder
self.remainder.unwrap()
Comment on lines +50 to +53
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@scottmcm scottmcm Nov 17, 2025

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Would it be worth restructuring this to avoid needing the unwrap?

I'm imagining something like

Suggested change
while self.remainder.is_none() {
let _ = self.next();
}
self.remainder
self.remainder.unwrap()
loop {
if let Some(r) = self.remainder {
return r;
}
let _ = self.next();
}

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@hkBst hkBst Nov 17, 2025

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While that is indeed equivalent it has the downside of the loop then being slightly more complicated, but let me know if you want it changed.

@rustbot ready

}
}

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2 changes: 1 addition & 1 deletion library/core/src/iter/traits/iterator.rs
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Expand Up @@ -3523,7 +3523,7 @@ pub trait Iterator {
/// assert_eq!(iter.next(), Some(['l', 'o']));
/// assert_eq!(iter.next(), Some(['r', 'e']));
/// assert_eq!(iter.next(), None);
/// assert_eq!(iter.into_remainder().unwrap().as_slice(), &['m']);
/// assert_eq!(iter.into_remainder().as_slice(), &['m']);
/// ```
///
/// ```
Expand Down
10 changes: 5 additions & 5 deletions library/coretests/tests/iter/adapters/array_chunks.rs
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Expand Up @@ -18,10 +18,10 @@ fn test_iterator_array_chunks_clone_and_drop() {
assert_eq!(count.get(), 3);
let mut it2 = it.clone();
assert_eq!(count.get(), 3);
assert_eq!(it.into_remainder().unwrap().len(), 2);
assert_eq!(it.into_remainder().len(), 2);
assert_eq!(count.get(), 5);
assert!(it2.next().is_none());
assert_eq!(it2.into_remainder().unwrap().len(), 2);
assert_eq!(it2.into_remainder().len(), 2);
assert_eq!(count.get(), 7);
}

Expand All @@ -31,7 +31,7 @@ fn test_iterator_array_chunks_remainder() {
assert_eq!(it.next(), Some([0, 1, 2, 3]));
assert_eq!(it.next(), Some([4, 5, 6, 7]));
assert_eq!(it.next(), None);
assert_eq!(it.into_remainder().unwrap().as_slice(), &[8, 9, 10]);
assert_eq!(it.into_remainder().as_slice(), &[8, 9, 10]);
}

#[test]
Expand Down Expand Up @@ -89,7 +89,7 @@ fn test_iterator_array_chunks_next_and_next_back() {
assert_eq!(it.next(), None);
assert_eq!(it.next_back(), None);
assert_eq!(it.next(), None);
assert_eq!(it.into_remainder().unwrap().as_slice(), &[9, 10]);
assert_eq!(it.into_remainder().as_slice(), &[9, 10]);
}

#[test]
Expand All @@ -102,7 +102,7 @@ fn test_iterator_array_chunks_rev_remainder() {
assert_eq!(it.next(), None);
assert_eq!(it.next(), None);
}
assert_eq!(it.into_remainder().unwrap().as_slice(), &[8, 9, 10]);
assert_eq!(it.into_remainder().as_slice(), &[8, 9, 10]);
}

#[test]
Expand Down
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