51     last: Option<Box<T>>,
78     pub fn first(&self) -> Option<&T> {  in first()
83     pub fn first_mut(&mut self) -> Option<&mut T> {  in first_mut()
88     pub fn last(&self) -> Option<&T> {  in last()
93     pub fn last_mut(&mut self) -> Option<&mut T> {  in last_mut()
98     pub fn get(&self, index: usize) -> Option<&T> {  in get()
109     pub fn get_mut(&mut self, index: usize) -> Option<&mut T> {  in get_mut()
208     pub fn pop(&mut self) -> Option<Pair<T, P>> {  in pop()
218     pub fn pop_punct(&mut self) -> Option<P> {  in pop_punct()
570     fn next(&mut self) -> Option<Self::Item> {  in next()
577     fn size_hint(&self) -> (usize, Option<usize>) {  in size_hint()
583     fn next_back(&mut self) -> Option<Self::Item> {  in next_back()
620     fn next(&mut self) -> Option<Self::Item> {  in next()
627     fn size_hint(&self) -> (usize, Option<usize>) {  in size_hint()
633     fn next_back(&mut self) -> Option<Self::Item> {  in next_back()
660     fn next(&mut self) -> Option<Self::Item> {  in next()
667     fn size_hint(&self) -> (usize, Option<usize>) {  in size_hint()
673     fn next_back(&mut self) -> Option<Self::Item> {  in next_back()
712     fn next(&mut self) -> Option<Self::Item> {  in next()
716     fn size_hint(&self) -> (usize, Option<usize>) {  in size_hint()
722     fn next_back(&mut self) -> Option<Self::Item> {  in next_back()
788     fn next(&mut self) -> Option<Self::Item> {  in next()
792     fn size_hint(&self) -> (usize, Option<usize>) {  in size_hint()
798     fn next_back(&mut self) -> Option<Self::Item> {  in next_back()
812     fn next(&mut self) -> Option<Self::Item> {  in next()
821     fn next_back(&mut self) -> Option<Self::Item> {  in next_back()
894     fn next(&mut self) -> Option<Self::Item> {  in next()
898     fn size_hint(&self) -> (usize, Option<usize>) {  in size_hint()
904     fn next_back(&mut self) -> Option<Self::Item> {  in next_back()
918     fn next(&mut self) -> Option<Self::Item> {  in next()
927     fn next_back(&mut self) -> Option<Self::Item> {  in next_back()
983     pub fn punct(&self) -> Option<&P> {  in punct()
1008     pub fn punct_mut(&mut self) -> Option<&mut P> {  in punct_mut()
1017     pub fn new(t: T, p: Option<P>) -> Self {  in new()
1026     pub fn into_tuple(self) -> (T, Option<P>) {  in into_tuple()