pub(crate) struct ReversibleIterable<It> {    pub(crate) it: It,    pub(crate) reverse: bool,} impl<T> ReversibleIterable<T> {    pub(crate) fn new(it: T, reverse: bool) -> Self {        Self { it, reverse }    }} impl<It, Item> ReversibleIterable<It>where    It: Iterator<Item = Item>,{    pub(crate) fn find_single_ended<F>(mut self, pred: F) -> Option<Item>    where        F: FnMut(&Item) -> bool,    {        if self.reverse {            self.it.filter(pred).last()        } else {            self.it.find(pred)        }    }} impl<It, Item> ReversibleIterable<It>where    It: DoubleEndedIterator<Item = Item>,{    pub(crate) fn find<F>(mut self, mut pred: F) -> Option<Item>    where        F: FnMut(&Item) -> bool,    {        if self.reverse {            self.it.rfind(|x| pred(x))        } else {            self.it.find(|x| pred(x))        }    }}