Struct core::iter::Peekable

#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
pub struct Peekable<I: Iterator> {
    // some fields omitted
}

An iterator with a peek() that returns an optional reference to the next element.

Methods

impl<I: Iterator> Peekable<I>

fn peek(&mut self) -> Option<&I::Item>

Returns a reference to the next element of the iterator with out advancing it, or None if the iterator is exhausted.

fn is_empty(&mut self) -> bool

Unstable

Checks whether peekable iterator is empty or not.

Trait Implementations

impl<I: Iterator + Clone> Clone for Peekable<I> where I::Item: Clone

fn clone(&self) -> Peekable<I>

fn clone_from(&mut self, source: &Self)

impl<I: Iterator> Iterator for Peekable<I>

type Item = I::Item

fn next(&mut self) -> Option<I::Item>

fn count(self) -> usize

fn nth(&mut self, n: usize) -> Option<I::Item>

fn last(self) -> Option<I::Item>

fn size_hint(&self) -> (usize, Option<usize>)

fn chain<U>(self, other: U) -> Chain<Self, U::IntoIter> where Self: Sized, U: IntoIterator<Item=Self::Item>

fn zip<U>(self, other: U) -> Zip<Self, U::IntoIter> where Self: Sized, U: IntoIterator

fn map<B, F>(self, f: F) -> Map<Self, F> where Self: Sized, F: FnMut(Self::Item) -> B

fn filter<P>(self, predicate: P) -> Filter<Self, P> where Self: Sized, P: FnMut(&Self::Item) -> bool

fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F> where Self: Sized, F: FnMut(Self::Item) -> Option<B>

fn enumerate(self) -> Enumerate<Self> where Self: Sized

fn peekable(self) -> Peekable<Self> where Self: Sized

fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P> where Self: Sized, P: FnMut(&Self::Item) -> bool

fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P> where Self: Sized, P: FnMut(&Self::Item) -> bool

fn skip(self, n: usize) -> Skip<Self> where Self: Sized

fn take(self, n: usize) -> Take<Self> where Self: Sized

fn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F> where Self: Sized, F: FnMut(&mut St, Self::Item) -> Option<B>

fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F> where Self: Sized, U: IntoIterator, F: FnMut(Self::Item) -> U

fn fuse(self) -> Fuse<Self> where Self: Sized

fn inspect<F>(self, f: F) -> Inspect<Self, F> where Self: Sized, F: FnMut(&Self::Item)

fn by_ref(&mut self) -> &mut Self where Self: Sized

fn collect<B: FromIterator<Self::Item>>(self) -> B where Self: Sized

fn partition<B, F>(self, f: F) -> (B, B) where Self: Sized, B: Default + Extend<Self::Item>, F: FnMut(&Self::Item) -> bool

fn fold<B, F>(self, init: B, f: F) -> B where Self: Sized, F: FnMut(B, Self::Item) -> B

fn all<F>(&mut self, f: F) -> bool where Self: Sized, F: FnMut(Self::Item) -> bool

fn any<F>(&mut self, f: F) -> bool where Self: Sized, F: FnMut(Self::Item) -> bool

fn find<P>(&mut self, predicate: P) -> Option<Self::Item> where Self: Sized, P: FnMut(&Self::Item) -> bool

fn position<P>(&mut self, predicate: P) -> Option<usize> where Self: Sized, P: FnMut(Self::Item) -> bool

fn rposition<P>(&mut self, predicate: P) -> Option<usize> where P: FnMut(Self::Item) -> bool, Self: Sized + ExactSizeIterator + DoubleEndedIterator

fn max(self) -> Option<Self::Item> where Self: Sized, Self::Item: Ord

fn min(self) -> Option<Self::Item> where Self: Sized, Self::Item: Ord

fn min_max(self) -> MinMaxResult<Self::Item> where Self: Sized, Self::Item: Ord

fn max_by<B: Ord, F>(self, f: F) -> Option<Self::Item> where Self: Sized, F: FnMut(&Self::Item) -> B

fn min_by<B: Ord, F>(self, f: F) -> Option<Self::Item> where Self: Sized, F: FnMut(&Self::Item) -> B

fn rev(self) -> Rev<Self> where Self: Sized + DoubleEndedIterator

fn unzip<A, B, FromA, FromB>(self) -> (FromA, FromB) where FromA: Default + Extend<A>, FromB: Default + Extend<B>, Self: Sized + Iterator<Item=(A, B)>

fn cloned<'a, T: 'a>(self) -> Cloned<Self> where Self: Sized + Iterator<Item=&'a T>, T: Clone

fn cycle(self) -> Cycle<Self> where Self: Sized + Clone

fn reverse_in_place<'a, T: 'a>(&mut self) where Self: Sized + Iterator<Item=&'a mut T> + DoubleEndedIterator

fn sum<S = Self::Item>(self) -> S where S: Add<Self::Item, Output=S> + Zero, Self: Sized

fn product<P = Self::Item>(self) -> P where P: Mul<Self::Item, Output=P> + One, Self: Sized

impl<I: ExactSizeIterator> ExactSizeIterator for Peekable<I>

fn len(&self) -> usize