Clarify that guarantees extend to other advancing iterator methods.

This commit is contained in:
The8472 2021-01-30 18:07:48 +01:00
parent 7ce1b3b244
commit 55d6247f52

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@ -43,12 +43,14 @@ unsafe impl<I: TrustedLen + ?Sized> TrustedLen for &mut I {}
/// An iterator that when yielding an item will have taken at least one element
/// from its underlying [`SourceIter`].
///
/// Calling [`next()`] guarantees that at least one value of the iterator's underlying source
/// has been moved out and the result of the iterator chain could be inserted in its place,
/// assuming structural constraints of the source allow such an insertion.
/// Calling any method that advances the iterator, e.g. [`next()`] or [`try_fold()`],
/// guarantees that for each step at least one value of the iterator's underlying source
/// has been moved out and the result of the iterator chain could be inserted
/// in its place, assuming structural constraints of the source allow such an insertion.
/// In other words this trait indicates that an iterator pipeline can be collected in place.
///
/// [`SourceIter`]: crate::iter::SourceIter
/// [`next()`]: Iterator::next
/// [`try_fold()`]: Iterator::try_fold
#[unstable(issue = "none", feature = "inplace_iteration")]
pub unsafe trait InPlaceIterable: Iterator {}