Struct Empty

pub struct Empty<T, E>(/* private fields */);

An iterator over no items.

Trait Implementations

impl<T, E> DoubleEndedFallibleStreamingIterator for Empty<T, E>

fn advance_back(&mut self) -> Result<(), E>

Advances the state of the iterator to the next item from the end.

fn next_back(&mut self) -> Result<Option<&Self::Item>, Self::Error>

Advances the back of the iterator, returning the last element.

impl<T, E> FallibleStreamingIterator for Empty<T, E>

type Item = T

The type being iterated over.

type Error = E

The error type of iteration.

fn advance(&mut self) -> Result<(), E>

Advances the iterator to the next position.

fn get(&self) -> Option<&T>

Returns the current element.

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

Returns bounds on the number of remaining elements in the iterator.

fn next(&mut self) -> Result<Option<&Self::Item>, Self::Error>

Advances the iterator, returning the next element.

fn all<F>(&mut self, f: F) -> Result<bool, Self::Error>

where Self: Sized, F: FnMut(&Self::Item) -> bool,

Determines if all elements of the iterator satisfy a predicate.

fn any<F>(&mut self, f: F) -> Result<bool, Self::Error>

where Self: Sized, F: FnMut(&Self::Item) -> bool,

Determines if any elements of the iterator satisfy a predicate.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Borrows an iterator, rather than consuming it.

fn count(self) -> Result<usize, Self::Error>

where Self: Sized,

Returns the number of remaining elements in the iterator.

fn filter<F>(self, f: F) -> Filter<Self, F>

where Self: Sized, F: FnMut(&Self::Item) -> bool,

Returns an iterator which filters elements by a predicate.

fn find<F>(&mut self, f: F) -> Result<Option<&Self::Item>, Self::Error>

where Self: Sized, F: FnMut(&Self::Item) -> bool,

Returns the first element of the iterator which satisfies a predicate.

fn for_each<F>(self, f: F) -> Result<(), Self::Error>

where Self: Sized, F: FnMut(&Self::Item),

Calls a closure on each element of an iterator.

fn fuse(self) -> Fuse<Self>

where Self: Sized,

Returns an iterator which is well-behaved at the beginning and end of iteration.

fn map<F, B>(self, f: F) -> Map<Self, F, B>

where Self: Sized, F: FnMut(&Self::Item) -> B,

Returns an iterator which applies a transform to elements.

fn map_ref<F, B: ?Sized>(self, f: F) -> MapRef<Self, F>

where Self: Sized, F: Fn(&Self::Item) -> &B,

Returns an iterator which applies a transform to elements.

fn map_err<F, B>(self, f: F) -> MapErr<Self, F>

where Self: Sized, F: Fn(Self::Error) -> B,

Returns an iterator that applies a transform to errors.

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

Returns the nth element of the iterator.

fn position<F>(&mut self, f: F) -> Result<Option<usize>, Self::Error>

where Self: Sized, F: FnMut(&Self::Item) -> bool,

Returns the position of the first element matching a predicate.

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

where Self: Sized,

Returns an iterator which skips the first n elements.

fn skip_while<F>(self, f: F) -> SkipWhile<Self, F>

where Self: Sized, F: FnMut(&Self::Item) -> bool,

Returns an iterator which skips the first sequence of elements matching a predicate.

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

where Self: Sized,

Returns an iterator which only returns the first n elements.

fn take_while<F>(self, f: F) -> TakeWhile<Self, F>

where Self: Sized, F: FnMut(&Self::Item) -> bool,

Returns an iterator which only returns the first sequence of elements matching a predicate.