pub trait DoubleEndedStreamingIterator: StreamingIterator {
fn advance_back(&mut self);
fn next_back(&mut self) -> Option<&Self::Item> { ... }
fn rfold<B, F>(self, init: B, f: F) -> B
where
Self: Sized,
F: FnMut(B, &Self::Item) -> B,
{ ... }
}
Expand description
A streaming iterator able to yield elements from both ends.
Required methods
fn advance_back(&mut self)
fn advance_back(&mut self)
Advances the iterator to the next element from the back of the iterator.
Double ended iterators just after the last element, so this should be called before get
when iterating in reverse.
The behavior of calling this method after the iterator has been exhausted is unspecified.
Provided methods
Advances the iterator and returns the next value from the back.
The behavior of calling this method after the iterator has been exhausted is unspecified.
The default implementation simply calls advance_back
followed by get
.