Struct itertools::structs::PeekNth[][src]

pub struct PeekNth<I> where
    I: Iterator
{ /* fields omitted */ }

See peek_nth() for more information.

Implementations

impl<I> PeekNth<I> where
    I: Iterator
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pub fn peek(&mut self) -> Option<&I::Item>[src]

Works exactly like the peek method in std::iter::Peekable

pub fn peek_nth(&mut self, n: usize) -> Option<&I::Item>[src]

Returns a reference to the nth value without advancing the iterator.

Examples

Basic usage:

use itertools::peek_nth;

let xs = vec![1,2,3];
let mut iter = peek_nth(xs.iter());

assert_eq!(iter.peek_nth(0), Some(&&1));
assert_eq!(iter.next(), Some(&1));

// The iterator does not advance even if we call `peek_nth` multiple times
assert_eq!(iter.peek_nth(0), Some(&&2));
assert_eq!(iter.peek_nth(1), Some(&&3));
assert_eq!(iter.next(), Some(&2));

// Calling `peek_nth` past the end of the iterator will return `None`
assert_eq!(iter.peek_nth(1), None);

Trait Implementations

impl<I: Clone> Clone for PeekNth<I> where
    I: Iterator,
    I::Item: Clone
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impl<I: Debug> Debug for PeekNth<I> where
    I: Iterator,
    I::Item: Debug
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impl<I> ExactSizeIterator for PeekNth<I> where
    I: ExactSizeIterator
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impl<I> Iterator for PeekNth<I> where
    I: Iterator
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type Item = I::Item

The type of the elements being iterated over.

impl<I> PeekingNext for PeekNth<I> where
    I: Iterator
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Auto Trait Implementations

impl<I> RefUnwindSafe for PeekNth<I> where
    I: RefUnwindSafe,
    <I as Iterator>::Item: RefUnwindSafe

impl<I> Send for PeekNth<I> where
    I: Send,
    <I as Iterator>::Item: Send

impl<I> Sync for PeekNth<I> where
    I: Sync,
    <I as Iterator>::Item: Sync

impl<I> Unpin for PeekNth<I> where
    I: Unpin,
    <I as Iterator>::Item: Unpin

impl<I> UnwindSafe for PeekNth<I> where
    I: UnwindSafe,
    <I as Iterator>::Item: UnwindSafe

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized
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impl<T> Borrow<T> for T where
    T: ?Sized
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impl<T> BorrowMut<T> for T where
    T: ?Sized
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impl<T> From<T> for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, 
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impl<I> IntoIterator for I where
    I: Iterator
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type Item = <I as Iterator>::Item

The type of the elements being iterated over.

type IntoIter = I

Which kind of iterator are we turning this into?

impl<T> Itertools for T where
    T: Iterator + ?Sized
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impl<T> ToOwned for T where
    T: Clone
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type Owned = T

The resulting type after obtaining ownership.

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
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type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.