Tracking issue for std::iter::successors

[SimonSapin]

Implemented in #55869, previously tracked in #55977:

pub fn successors<T, F>(first: Option<T>, succ: F) -> Successors<T, F>
    where F: FnMut(&T) -> Option<T> {…}

#[derive(Clone)] pub struct Successors<T, F> {…}

impl<T, F> Iterator for Successors<T, F> where F: FnMut(&T) -> Option<T> {
    type Item = T;
}

impl<T, F> FusedIterator for Successors<T, F> where F: FnMut(&T) -> Option<T> {}

impl<T: fmt::Debug, F> fmt::Debug for Successors<T, F> {…}

[SimonSapin]

I’m separating tracking of successors from that of unfold since only the latter seems to have unresolved questions.

@rfcbot fcp merge

[rfcbot]

Team member @SimonSapin has proposed to merge this. The next step is review by the rest of the tagged team members:

• @Kimundi
• @SimonSapin
• @alexcrichton
• @dtolnay
• @sfackler
• @withoutboats

No concerns currently listed.

Once a majority of reviewers approve (and none object), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

See this document for info about what commands tagged team members can give me.

[rfcbot]

🔔 This is now entering its final comment period, as per the review above. 🔔

[rfcbot]

The final comment period, with a disposition to merge, as per the review above, is now complete.