Trait core::iter::DoubleEndedIterator 1.0.0[−][src]
pub trait DoubleEndedIterator: Iterator { fn next_back(&mut self) -> Option<Self::Item>; fn advance_back_by(&mut self, n: usize) -> Result<(), usize> { ... } fn nth_back(&mut self, n: usize) -> Option<Self::Item> { ... } fn try_rfold<B, F, R>(&mut self, init: B, f: F) -> R
where
Self: Sized,
F: FnMut(B, Self::Item) -> R,
R: Try<Ok = B>, { ... } fn rfold<B, F>(self, init: B, f: F) -> B
where
Self: Sized,
F: FnMut(B, Self::Item) -> B, { ... } fn rfind<P>(&mut self, predicate: P) -> Option<Self::Item>
where
Self: Sized,
P: FnMut(&Self::Item) -> bool, { ... } }
An iterator able to yield elements from both ends.
Something that implements DoubleEndedIterator
has one extra capability
over something that implements Iterator
: the ability to also take
Item
s from the back, as well as the front.
It is important to note that both back and forth work on the same range, and do not cross: iteration is over when they meet in the middle.
In a similar fashion to the Iterator
protocol, once a
DoubleEndedIterator
returns None
from a next_back()
, calling it
again may or may not ever return Some
again. next()
and
next_back()
are interchangeable for this purpose.
Examples
Basic usage:
let numbers = vec![1, 2, 3, 4, 5, 6]; let mut iter = numbers.iter(); assert_eq!(Some(&1), iter.next()); assert_eq!(Some(&6), iter.next_back()); assert_eq!(Some(&5), iter.next_back()); assert_eq!(Some(&2), iter.next()); assert_eq!(Some(&3), iter.next()); assert_eq!(Some(&4), iter.next()); assert_eq!(None, iter.next()); assert_eq!(None, iter.next_back());Run
Required methods
fn next_back(&mut self) -> Option<Self::Item>
[src]
Removes and returns an element from the end of the iterator.
Returns None
when there are no more elements.
The trait-level docs contain more details.
Examples
Basic usage:
let numbers = vec![1, 2, 3, 4, 5, 6]; let mut iter = numbers.iter(); assert_eq!(Some(&1), iter.next()); assert_eq!(Some(&6), iter.next_back()); assert_eq!(Some(&5), iter.next_back()); assert_eq!(Some(&2), iter.next()); assert_eq!(Some(&3), iter.next()); assert_eq!(Some(&4), iter.next()); assert_eq!(None, iter.next()); assert_eq!(None, iter.next_back());Run
Remarks
The elements yielded by DoubleEndedIterator
’s methods may differ from
the ones yielded by Iterator
’s methods:
let vec = vec![(1, 'a'), (1, 'b'), (1, 'c'), (2, 'a'), (2, 'b')]; let uniq_by_fst_comp = || { let mut seen = std::collections::HashSet::new(); vec.iter().copied().filter(move |x| seen.insert(x.0)) }; assert_eq!(uniq_by_fst_comp().last(), Some((2, 'a'))); assert_eq!(uniq_by_fst_comp().next_back(), Some((2, 'b'))); assert_eq!( uniq_by_fst_comp().fold(vec![], |mut v, x| {v.push(x); v}), vec![(1, 'a'), (2, 'a')] ); assert_eq!( uniq_by_fst_comp().rfold(vec![], |mut v, x| {v.push(x); v}), vec![(2, 'b'), (1, 'c')] );Run
Provided methods
fn advance_back_by(&mut self, n: usize) -> Result<(), usize>
[src]
🔬 This is a nightly-only experimental API. (iter_advance_by
#77404)
recently added
Advances the iterator from the back by n
elements.
advance_back_by
is the reverse version of advance_by
. This method will
eagerly skip n
elements starting from the back by calling next_back
up
to n
times until None
is encountered.
advance_back_by(n)
will return Ok(())
if the iterator successfully advances by
n
elements, or Err(k)
if None
is encountered, where k
is the number of
elements the iterator is advanced by before running out of elements (i.e. the length
of the iterator). Note that k
is always less than n
.
Calling advance_back_by(0)
does not consume any elements and always returns Ok(())
.
Examples
Basic usage:
#![feature(iter_advance_by)] let a = [3, 4, 5, 6]; let mut iter = a.iter(); assert_eq!(iter.advance_back_by(2), Ok(())); assert_eq!(iter.next_back(), Some(&4)); assert_eq!(iter.advance_back_by(0), Ok(())); assert_eq!(iter.advance_back_by(100), Err(1)); // only `&3` was skippedRun
fn nth_back(&mut self, n: usize) -> Option<Self::Item>
1.37.0[src]
Returns the n
th element from the end of the iterator.
This is essentially the reversed version of Iterator::nth()
.
Although like most indexing operations, the count starts from zero, so
nth_back(0)
returns the first value from the end, nth_back(1)
the
second, and so on.
Note that all elements between the end and the returned element will be
consumed, including the returned element. This also means that calling
nth_back(0)
multiple times on the same iterator will return different
elements.
nth_back()
will return None
if n
is greater than or equal to the
length of the iterator.
Examples
Basic usage:
let a = [1, 2, 3]; assert_eq!(a.iter().nth_back(2), Some(&1));Run
Calling nth_back()
multiple times doesn’t rewind the iterator:
let a = [1, 2, 3]; let mut iter = a.iter(); assert_eq!(iter.nth_back(1), Some(&2)); assert_eq!(iter.nth_back(1), None);Run
Returning None
if there are less than n + 1
elements:
let a = [1, 2, 3]; assert_eq!(a.iter().nth_back(10), None);Run
fn try_rfold<B, F, R>(&mut self, init: B, f: F) -> R where
Self: Sized,
F: FnMut(B, Self::Item) -> R,
R: Try<Ok = B>,
1.27.0[src]
Self: Sized,
F: FnMut(B, Self::Item) -> R,
R: Try<Ok = B>,
This is the reverse version of Iterator::try_fold()
: it takes
elements starting from the back of the iterator.
Examples
Basic usage:
let a = ["1", "2", "3"]; let sum = a.iter() .map(|&s| s.parse::<i32>()) .try_rfold(0, |acc, x| x.and_then(|y| Ok(acc + y))); assert_eq!(sum, Ok(6));Run
Short-circuiting:
let a = ["1", "rust", "3"]; let mut it = a.iter(); let sum = it .by_ref() .map(|&s| s.parse::<i32>()) .try_rfold(0, |acc, x| x.and_then(|y| Ok(acc + y))); assert!(sum.is_err()); // Because it short-circuited, the remaining elements are still // available through the iterator. assert_eq!(it.next_back(), Some(&"1"));Run
fn rfold<B, F>(self, init: B, f: F) -> B where
Self: Sized,
F: FnMut(B, Self::Item) -> B,
1.27.0[src]
Self: Sized,
F: FnMut(B, Self::Item) -> B,
An iterator method that reduces the iterator’s elements to a single, final value, starting from the back.
This is the reverse version of Iterator::fold()
: it takes elements
starting from the back of the iterator.
rfold()
takes two arguments: an initial value, and a closure with two
arguments: an ‘accumulator’, and an element. The closure returns the value that
the accumulator should have for the next iteration.
The initial value is the value the accumulator will have on the first call.
After applying this closure to every element of the iterator, rfold()
returns the accumulator.
This operation is sometimes called ‘reduce’ or ‘inject’.
Folding is useful whenever you have a collection of something, and want to produce a single value from it.
Examples
Basic usage:
let a = [1, 2, 3]; // the sum of all of the elements of a let sum = a.iter() .rfold(0, |acc, &x| acc + x); assert_eq!(sum, 6);Run
This example builds a string, starting with an initial value and continuing with each element from the back until the front:
let numbers = [1, 2, 3, 4, 5]; let zero = "0".to_string(); let result = numbers.iter().rfold(zero, |acc, &x| { format!("({} + {})", x, acc) }); assert_eq!(result, "(1 + (2 + (3 + (4 + (5 + 0)))))");Run
fn rfind<P>(&mut self, predicate: P) -> Option<Self::Item> where
Self: Sized,
P: FnMut(&Self::Item) -> bool,
1.27.0[src]
Self: Sized,
P: FnMut(&Self::Item) -> bool,
Searches for an element of an iterator from the back that satisfies a predicate.
rfind()
takes a closure that returns true
or false
. It applies
this closure to each element of the iterator, starting at the end, and if any
of them return true
, then rfind()
returns Some(element)
. If they all return
false
, it returns None
.
rfind()
is short-circuiting; in other words, it will stop processing
as soon as the closure returns true
.
Because rfind()
takes a reference, and many iterators iterate over
references, this leads to a possibly confusing situation where the
argument is a double reference. You can see this effect in the
examples below, with &&x
.
Examples
Basic usage:
let a = [1, 2, 3]; assert_eq!(a.iter().rfind(|&&x| x == 2), Some(&2)); assert_eq!(a.iter().rfind(|&&x| x == 5), None);Run
Stopping at the first true
:
let a = [1, 2, 3]; let mut iter = a.iter(); assert_eq!(iter.rfind(|&&x| x == 2), Some(&2)); // we can still use `iter`, as there are more elements. assert_eq!(iter.next_back(), Some(&1));Run
Implementors
impl DoubleEndedIterator for EscapeDefault
[src]
impl DoubleEndedIterator for EscapeDefault
[src]impl DoubleEndedIterator for Bytes<'_>
[src]
impl DoubleEndedIterator for Bytes<'_>
[src]impl<'a> DoubleEndedIterator for EscapeAscii<'a>
[src]
impl<'a> DoubleEndedIterator for EscapeAscii<'a>
[src]impl<'a> DoubleEndedIterator for CharIndices<'a>
[src]
impl<'a> DoubleEndedIterator for CharIndices<'a>
[src]impl<'a> DoubleEndedIterator for SplitAsciiWhitespace<'a>
1.34.0[src]
impl<'a> DoubleEndedIterator for SplitAsciiWhitespace<'a>
1.34.0[src]impl<'a> DoubleEndedIterator for SplitWhitespace<'a>
1.1.0[src]
impl<'a> DoubleEndedIterator for SplitWhitespace<'a>
1.1.0[src]impl<'a, A> DoubleEndedIterator for core::option::Iter<'a, A>
[src]
impl<'a, A> DoubleEndedIterator for core::option::Iter<'a, A>
[src]impl<'a, A> DoubleEndedIterator for core::option::IterMut<'a, A>
[src]
impl<'a, A> DoubleEndedIterator for core::option::IterMut<'a, A>
[src]impl<'a, I, T: 'a> DoubleEndedIterator for Cloned<I> where
I: DoubleEndedIterator<Item = &'a T>,
T: Clone,
1.1.0[src]
impl<'a, I, T: 'a> DoubleEndedIterator for Cloned<I> where
I: DoubleEndedIterator<Item = &'a T>,
T: Clone,
1.1.0[src]impl<'a, I, T: 'a> DoubleEndedIterator for Copied<I> where
I: DoubleEndedIterator<Item = &'a T>,
T: Copy,
1.36.0[src]
impl<'a, I, T: 'a> DoubleEndedIterator for Copied<I> where
I: DoubleEndedIterator<Item = &'a T>,
T: Copy,
1.36.0[src]impl<'a, I: DoubleEndedIterator + ?Sized> DoubleEndedIterator for &'a mut I
[src]
impl<'a, I: DoubleEndedIterator + ?Sized> DoubleEndedIterator for &'a mut I
[src]impl<'a, P> DoubleEndedIterator for MatchIndices<'a, P> where
P: Pattern<'a, Searcher: DoubleEndedSearcher<'a>>,
1.5.0[src]
impl<'a, P> DoubleEndedIterator for MatchIndices<'a, P> where
P: Pattern<'a, Searcher: DoubleEndedSearcher<'a>>,
1.5.0[src]impl<'a, P> DoubleEndedIterator for Matches<'a, P> where
P: Pattern<'a, Searcher: DoubleEndedSearcher<'a>>,
1.2.0[src]
impl<'a, P> DoubleEndedIterator for Matches<'a, P> where
P: Pattern<'a, Searcher: DoubleEndedSearcher<'a>>,
1.2.0[src]impl<'a, P> DoubleEndedIterator for RMatchIndices<'a, P> where
P: Pattern<'a, Searcher: DoubleEndedSearcher<'a>>,
1.5.0[src]
impl<'a, P> DoubleEndedIterator for RMatchIndices<'a, P> where
P: Pattern<'a, Searcher: DoubleEndedSearcher<'a>>,
1.5.0[src]impl<'a, P> DoubleEndedIterator for RMatches<'a, P> where
P: Pattern<'a, Searcher: DoubleEndedSearcher<'a>>,
1.2.0[src]
impl<'a, P> DoubleEndedIterator for RMatches<'a, P> where
P: Pattern<'a, Searcher: DoubleEndedSearcher<'a>>,
1.2.0[src]impl<'a, P> DoubleEndedIterator for core::str::RSplit<'a, P> where
P: Pattern<'a, Searcher: DoubleEndedSearcher<'a>>,
[src]
impl<'a, P> DoubleEndedIterator for core::str::RSplit<'a, P> where
P: Pattern<'a, Searcher: DoubleEndedSearcher<'a>>,
[src]impl<'a, P> DoubleEndedIterator for RSplitTerminator<'a, P> where
P: Pattern<'a, Searcher: DoubleEndedSearcher<'a>>,
[src]
impl<'a, P> DoubleEndedIterator for RSplitTerminator<'a, P> where
P: Pattern<'a, Searcher: DoubleEndedSearcher<'a>>,
[src]impl<'a, P> DoubleEndedIterator for core::str::Split<'a, P> where
P: Pattern<'a, Searcher: DoubleEndedSearcher<'a>>,
[src]
impl<'a, P> DoubleEndedIterator for core::str::Split<'a, P> where
P: Pattern<'a, Searcher: DoubleEndedSearcher<'a>>,
[src]impl<'a, P> DoubleEndedIterator for SplitTerminator<'a, P> where
P: Pattern<'a, Searcher: DoubleEndedSearcher<'a>>,
[src]
impl<'a, P> DoubleEndedIterator for SplitTerminator<'a, P> where
P: Pattern<'a, Searcher: DoubleEndedSearcher<'a>>,
[src]impl<'a, P: Pattern<'a, Searcher: ReverseSearcher<'a>>> DoubleEndedIterator for core::str::SplitInclusive<'a, P>
1.51.0[src]
impl<'a, P: Pattern<'a, Searcher: ReverseSearcher<'a>>> DoubleEndedIterator for core::str::SplitInclusive<'a, P>
1.51.0[src]impl<'a, T> DoubleEndedIterator for core::result::Iter<'a, T>
[src]
impl<'a, T> DoubleEndedIterator for core::result::Iter<'a, T>
[src]impl<'a, T> DoubleEndedIterator for core::result::IterMut<'a, T>
[src]
impl<'a, T> DoubleEndedIterator for core::result::IterMut<'a, T>
[src]impl<'a, T> DoubleEndedIterator for Chunks<'a, T>
[src]
impl<'a, T> DoubleEndedIterator for Chunks<'a, T>
[src]impl<'a, T> DoubleEndedIterator for ChunksExact<'a, T>
1.31.0[src]
impl<'a, T> DoubleEndedIterator for ChunksExact<'a, T>
1.31.0[src]impl<'a, T> DoubleEndedIterator for ChunksExactMut<'a, T>
1.31.0[src]
impl<'a, T> DoubleEndedIterator for ChunksExactMut<'a, T>
1.31.0[src]impl<'a, T> DoubleEndedIterator for ChunksMut<'a, T>
[src]
impl<'a, T> DoubleEndedIterator for ChunksMut<'a, T>
[src]impl<'a, T> DoubleEndedIterator for core::slice::Iter<'a, T>
[src]
impl<'a, T> DoubleEndedIterator for core::slice::Iter<'a, T>
[src]impl<'a, T> DoubleEndedIterator for core::slice::IterMut<'a, T>
[src]
impl<'a, T> DoubleEndedIterator for core::slice::IterMut<'a, T>
[src]impl<'a, T> DoubleEndedIterator for RChunks<'a, T>
1.31.0[src]
impl<'a, T> DoubleEndedIterator for RChunks<'a, T>
1.31.0[src]impl<'a, T> DoubleEndedIterator for RChunksExact<'a, T>
1.31.0[src]
impl<'a, T> DoubleEndedIterator for RChunksExact<'a, T>
1.31.0[src]impl<'a, T> DoubleEndedIterator for RChunksExactMut<'a, T>
1.31.0[src]
impl<'a, T> DoubleEndedIterator for RChunksExactMut<'a, T>
1.31.0[src]impl<'a, T> DoubleEndedIterator for RChunksMut<'a, T>
1.31.0[src]
impl<'a, T> DoubleEndedIterator for RChunksMut<'a, T>
1.31.0[src]impl<'a, T> DoubleEndedIterator for Windows<'a, T>
[src]
impl<'a, T> DoubleEndedIterator for Windows<'a, T>
[src]impl<'a, T, P> DoubleEndedIterator for core::slice::RSplit<'a, T, P> where
P: FnMut(&T) -> bool,
1.27.0[src]
impl<'a, T, P> DoubleEndedIterator for core::slice::RSplit<'a, T, P> where
P: FnMut(&T) -> bool,
1.27.0[src]impl<'a, T, P> DoubleEndedIterator for RSplitMut<'a, T, P> where
P: FnMut(&T) -> bool,
1.27.0[src]
impl<'a, T, P> DoubleEndedIterator for RSplitMut<'a, T, P> where
P: FnMut(&T) -> bool,
1.27.0[src]impl<'a, T, P> DoubleEndedIterator for core::slice::Split<'a, T, P> where
P: FnMut(&T) -> bool,
[src]
impl<'a, T, P> DoubleEndedIterator for core::slice::Split<'a, T, P> where
P: FnMut(&T) -> bool,
[src]impl<'a, T, P> DoubleEndedIterator for core::slice::SplitInclusive<'a, T, P> where
P: FnMut(&T) -> bool,
1.51.0[src]
impl<'a, T, P> DoubleEndedIterator for core::slice::SplitInclusive<'a, T, P> where
P: FnMut(&T) -> bool,
1.51.0[src]impl<'a, T, P> DoubleEndedIterator for SplitInclusiveMut<'a, T, P> where
P: FnMut(&T) -> bool,
1.51.0[src]
impl<'a, T, P> DoubleEndedIterator for SplitInclusiveMut<'a, T, P> where
P: FnMut(&T) -> bool,
1.51.0[src]impl<'a, T, P> DoubleEndedIterator for SplitMut<'a, T, P> where
P: FnMut(&T) -> bool,
[src]
impl<'a, T, P> DoubleEndedIterator for SplitMut<'a, T, P> where
P: FnMut(&T) -> bool,
[src]impl<'a, T, const N: usize> DoubleEndedIterator for ArrayChunks<'a, T, N>
[src]
impl<'a, T, const N: usize> DoubleEndedIterator for ArrayChunks<'a, T, N>
[src]impl<'a, T, const N: usize> DoubleEndedIterator for ArrayChunksMut<'a, T, N>
[src]
impl<'a, T, const N: usize> DoubleEndedIterator for ArrayChunksMut<'a, T, N>
[src]impl<'a, T, const N: usize> DoubleEndedIterator for ArrayWindows<'a, T, N>
[src]
impl<'a, T, const N: usize> DoubleEndedIterator for ArrayWindows<'a, T, N>
[src]impl<'a, T: 'a, P> DoubleEndedIterator for GroupBy<'a, T, P> where
P: FnMut(&T, &T) -> bool,
[src]
impl<'a, T: 'a, P> DoubleEndedIterator for GroupBy<'a, T, P> where
P: FnMut(&T, &T) -> bool,
[src]impl<'a, T: 'a, P> DoubleEndedIterator for GroupByMut<'a, T, P> where
P: FnMut(&T, &T) -> bool,
[src]
impl<'a, T: 'a, P> DoubleEndedIterator for GroupByMut<'a, T, P> where
P: FnMut(&T, &T) -> bool,
[src]impl<A> DoubleEndedIterator for core::option::IntoIter<A>
[src]
impl<A> DoubleEndedIterator for core::option::IntoIter<A>
[src]impl<A, B> DoubleEndedIterator for Chain<A, B> where
A: DoubleEndedIterator,
B: DoubleEndedIterator<Item = A::Item>,
[src]
impl<A, B> DoubleEndedIterator for Chain<A, B> where
A: DoubleEndedIterator,
B: DoubleEndedIterator<Item = A::Item>,
[src]fn next_back(&mut self) -> Option<A::Item>
[src]
fn advance_back_by(&mut self, n: usize) -> Result<(), usize>
[src]
fn nth_back(&mut self, n: usize) -> Option<Self::Item>
[src]
fn rfind<P>(&mut self, predicate: P) -> Option<Self::Item> where
P: FnMut(&Self::Item) -> bool,
[src]
P: FnMut(&Self::Item) -> bool,
fn try_rfold<Acc, F, R>(&mut self, acc: Acc, f: F) -> R where
Self: Sized,
F: FnMut(Acc, Self::Item) -> R,
R: Try<Ok = Acc>,
[src]
Self: Sized,
F: FnMut(Acc, Self::Item) -> R,
R: Try<Ok = Acc>,
fn rfold<Acc, F>(self, acc: Acc, f: F) -> Acc where
F: FnMut(Acc, Self::Item) -> Acc,
[src]
F: FnMut(Acc, Self::Item) -> Acc,
impl<A, B> DoubleEndedIterator for Zip<A, B> where
A: DoubleEndedIterator + ExactSizeIterator,
B: DoubleEndedIterator + ExactSizeIterator,
[src]
impl<A, B> DoubleEndedIterator for Zip<A, B> where
A: DoubleEndedIterator + ExactSizeIterator,
B: DoubleEndedIterator + ExactSizeIterator,
[src]impl<A, F: FnOnce() -> A> DoubleEndedIterator for OnceWith<F>
1.43.0[src]
impl<A, F: FnOnce() -> A> DoubleEndedIterator for OnceWith<F>
1.43.0[src]impl<A: Step> DoubleEndedIterator for Range<A>
[src]
impl<A: Step> DoubleEndedIterator for Range<A>
[src]impl<A: Step> DoubleEndedIterator for RangeInclusive<A>
1.26.0[src]
impl<A: Step> DoubleEndedIterator for RangeInclusive<A>
1.26.0[src]fn next_back(&mut self) -> Option<A>
[src]
fn nth_back(&mut self, n: usize) -> Option<A>
[src]
fn try_rfold<B, F, R>(&mut self, init: B, f: F) -> R where
Self: Sized,
F: FnMut(B, Self::Item) -> R,
R: Try<Ok = B>,
[src]
Self: Sized,
F: FnMut(B, Self::Item) -> R,
R: Try<Ok = B>,
fn rfold<B, F>(self, init: B, f: F) -> B where
Self: Sized,
F: FnMut(B, Self::Item) -> B,
[src]
Self: Sized,
F: FnMut(B, Self::Item) -> B,
impl<B, I: DoubleEndedIterator, F> DoubleEndedIterator for FilterMap<I, F> where
F: FnMut(I::Item) -> Option<B>,
[src]
impl<B, I: DoubleEndedIterator, F> DoubleEndedIterator for FilterMap<I, F> where
F: FnMut(I::Item) -> Option<B>,
[src]impl<B, I: DoubleEndedIterator, F> DoubleEndedIterator for Map<I, F> where
F: FnMut(I::Item) -> B,
[src]
impl<B, I: DoubleEndedIterator, F> DoubleEndedIterator for Map<I, F> where
F: FnMut(I::Item) -> B,
[src]impl<I> DoubleEndedIterator for Enumerate<I> where
I: ExactSizeIterator + DoubleEndedIterator,
[src]
impl<I> DoubleEndedIterator for Enumerate<I> where
I: ExactSizeIterator + DoubleEndedIterator,
[src]fn next_back(&mut self) -> Option<(usize, <I as Iterator>::Item)>
[src]
fn nth_back(&mut self, n: usize) -> Option<(usize, <I as Iterator>::Item)>
[src]
fn try_rfold<Acc, Fold, R>(&mut self, init: Acc, fold: Fold) -> R where
Self: Sized,
Fold: FnMut(Acc, Self::Item) -> R,
R: Try<Ok = Acc>,
[src]
Self: Sized,
Fold: FnMut(Acc, Self::Item) -> R,
R: Try<Ok = Acc>,
fn rfold<Acc, Fold>(self, init: Acc, fold: Fold) -> Acc where
Fold: FnMut(Acc, Self::Item) -> Acc,
[src]
Fold: FnMut(Acc, Self::Item) -> Acc,
impl<I> DoubleEndedIterator for Fuse<I> where
I: DoubleEndedIterator,
[src]
impl<I> DoubleEndedIterator for Fuse<I> where
I: DoubleEndedIterator,
[src]fn next_back(&mut self) -> Option<<I as Iterator>::Item>
[src]
fn nth_back(&mut self, n: usize) -> Option<<I as Iterator>::Item>
[src]
fn try_rfold<Acc, Fold, R>(&mut self, acc: Acc, fold: Fold) -> R where
Self: Sized,
Fold: FnMut(Acc, Self::Item) -> R,
R: Try<Ok = Acc>,
[src]
Self: Sized,
Fold: FnMut(Acc, Self::Item) -> R,
R: Try<Ok = Acc>,
fn rfold<Acc, Fold>(self, acc: Acc, fold: Fold) -> Acc where
Fold: FnMut(Acc, Self::Item) -> Acc,
[src]
Fold: FnMut(Acc, Self::Item) -> Acc,
fn rfind<P>(&mut self, predicate: P) -> Option<Self::Item> where
P: FnMut(&Self::Item) -> bool,
[src]
P: FnMut(&Self::Item) -> bool,
impl<I> DoubleEndedIterator for Peekable<I> where
I: DoubleEndedIterator,
1.38.0[src]
impl<I> DoubleEndedIterator for Peekable<I> where
I: DoubleEndedIterator,
1.38.0[src]impl<I> DoubleEndedIterator for Rev<I> where
I: DoubleEndedIterator,
[src]
impl<I> DoubleEndedIterator for Rev<I> where
I: DoubleEndedIterator,
[src]fn next_back(&mut self) -> Option<<I as Iterator>::Item>
[src]
fn advance_back_by(&mut self, n: usize) -> Result<(), usize>
[src]
fn nth_back(&mut self, n: usize) -> Option<<I as Iterator>::Item>
[src]
fn try_rfold<B, F, R>(&mut self, init: B, f: F) -> R where
Self: Sized,
F: FnMut(B, Self::Item) -> R,
R: Try<Ok = B>,
[src]
Self: Sized,
F: FnMut(B, Self::Item) -> R,
R: Try<Ok = B>,
fn rfold<Acc, F>(self, init: Acc, f: F) -> Acc where
F: FnMut(Acc, Self::Item) -> Acc,
[src]
F: FnMut(Acc, Self::Item) -> Acc,
fn rfind<P>(&mut self, predicate: P) -> Option<Self::Item> where
P: FnMut(&Self::Item) -> bool,
[src]
P: FnMut(&Self::Item) -> bool,
impl<I> DoubleEndedIterator for Skip<I> where
I: DoubleEndedIterator + ExactSizeIterator,
1.9.0[src]
impl<I> DoubleEndedIterator for Skip<I> where
I: DoubleEndedIterator + ExactSizeIterator,
1.9.0[src]fn next_back(&mut self) -> Option<Self::Item>
[src]
fn nth_back(&mut self, n: usize) -> Option<I::Item>
[src]
fn try_rfold<Acc, Fold, R>(&mut self, init: Acc, fold: Fold) -> R where
Self: Sized,
Fold: FnMut(Acc, Self::Item) -> R,
R: Try<Ok = Acc>,
[src]
Self: Sized,
Fold: FnMut(Acc, Self::Item) -> R,
R: Try<Ok = Acc>,
fn rfold<Acc, Fold>(self, init: Acc, fold: Fold) -> Acc where
Fold: FnMut(Acc, Self::Item) -> Acc,
[src]
Fold: FnMut(Acc, Self::Item) -> Acc,
impl<I> DoubleEndedIterator for StepBy<I> where
I: DoubleEndedIterator + ExactSizeIterator,
1.38.0[src]
impl<I> DoubleEndedIterator for StepBy<I> where
I: DoubleEndedIterator + ExactSizeIterator,
1.38.0[src]fn next_back(&mut self) -> Option<Self::Item>
[src]
fn nth_back(&mut self, n: usize) -> Option<Self::Item>
[src]
fn try_rfold<Acc, F, R>(&mut self, init: Acc, f: F) -> R where
F: FnMut(Acc, Self::Item) -> R,
R: Try<Ok = Acc>,
[src]
F: FnMut(Acc, Self::Item) -> R,
R: Try<Ok = Acc>,
fn rfold<Acc, F>(self, init: Acc, f: F) -> Acc where
Self: Sized,
F: FnMut(Acc, Self::Item) -> Acc,
[src]
Self: Sized,
F: FnMut(Acc, Self::Item) -> Acc,
impl<I> DoubleEndedIterator for Take<I> where
I: DoubleEndedIterator + ExactSizeIterator,
1.38.0[src]
impl<I> DoubleEndedIterator for Take<I> where
I: DoubleEndedIterator + ExactSizeIterator,
1.38.0[src]fn next_back(&mut self) -> Option<Self::Item>
[src]
fn nth_back(&mut self, n: usize) -> Option<Self::Item>
[src]
fn try_rfold<Acc, Fold, R>(&mut self, init: Acc, fold: Fold) -> R where
Self: Sized,
Fold: FnMut(Acc, Self::Item) -> R,
R: Try<Ok = Acc>,
[src]
Self: Sized,
Fold: FnMut(Acc, Self::Item) -> R,
R: Try<Ok = Acc>,
fn rfold<Acc, Fold>(self, init: Acc, fold: Fold) -> Acc where
Self: Sized,
Fold: FnMut(Acc, Self::Item) -> Acc,
[src]
Self: Sized,
Fold: FnMut(Acc, Self::Item) -> Acc,
impl<I, U> DoubleEndedIterator for Flatten<I> where
I: DoubleEndedIterator<Item: IntoIterator<IntoIter = U, Item = U::Item>>,
U: DoubleEndedIterator,
1.29.0[src]
impl<I, U> DoubleEndedIterator for Flatten<I> where
I: DoubleEndedIterator<Item: IntoIterator<IntoIter = U, Item = U::Item>>,
U: DoubleEndedIterator,
1.29.0[src]impl<I: DoubleEndedIterator, F> DoubleEndedIterator for Inspect<I, F> where
F: FnMut(&I::Item),
[src]
impl<I: DoubleEndedIterator, F> DoubleEndedIterator for Inspect<I, F> where
F: FnMut(&I::Item),
[src]impl<I: DoubleEndedIterator, P> DoubleEndedIterator for Filter<I, P> where
P: FnMut(&I::Item) -> bool,
[src]
impl<I: DoubleEndedIterator, P> DoubleEndedIterator for Filter<I, P> where
P: FnMut(&I::Item) -> bool,
[src]impl<I: DoubleEndedIterator, U, F> DoubleEndedIterator for FlatMap<I, U, F> where
F: FnMut(I::Item) -> U,
U: IntoIterator<IntoIter: DoubleEndedIterator>,
[src]
impl<I: DoubleEndedIterator, U, F> DoubleEndedIterator for FlatMap<I, U, F> where
F: FnMut(I::Item) -> U,
U: IntoIterator<IntoIter: DoubleEndedIterator>,
[src]impl<T> DoubleEndedIterator for core::result::IntoIter<T>
[src]
impl<T> DoubleEndedIterator for core::result::IntoIter<T>
[src]