1943     type Item = I::Item;  typedef
1944     fn next(&mut self) -> Option<I::Item> {  in next()
1950     fn nth(&mut self, n: usize) -> Option<I::Item> {  in nth()
1953     fn last(self) -> Option<I::Item> {  in last()
1959     type Item;  typedef
1960     fn last(self) -> Option<Self::Item>;  in last()
1964     type Item = I::Item;  typedef
1965     default fn last(self) -> Option<I::Item> {  in last()
1979     fn last(self) -> Option<I::Item> {  in last()
1986     fn next_back(&mut self) -> Option<I::Item> {  in next_back()
1989     fn nth_back(&mut self, n: usize) -> Option<I::Item> {  in nth_back()
2038     fn from_iter<T: IntoIterator<Item = I>>(iter: T) -> Self {  in from_iter()
2153     type Item = S::Item;  typedef
2155     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {  in poll_next()