fn is_double_ended(&self) -> bool {
        match self {
            Self::Iterator(..) => false,
            Self::DoubleEndedIterator(..) => true,
            Self::Map(iter) => iter.is_double_ended(),
            Self::FlatMap(iter) => iter.is_double_ended(),
            Self::Filter(iter) => iter.is_double_ended(),
            Self::Rev(..) => true,
            Self::Chain(iter) => iter.is_double_ended(),
            Self::Enumerate(iter) => iter.is_double_ended(),
            Self::Skip(iter) => iter.is_double_ended(),
            Self::Take(iter) => iter.is_double_ended(),
            Self::Peekable(iter) => iter.is_double_ended(),
            Self::Empty => true,
            Self::Once(..) => true,
        }
    }
/// Test if this iterator is double-ended.
Test if this iterator is double-ended.
Test if this iterator is double - ended .
fn is_double_ended(&self) -> bool {
        match self {
            Self::Iterator(..) => false,
            Self::DoubleEndedIterator(..) => true,
            Self::Map(iter) => iter.is_double_ended(),
            Self::FlatMap(iter) => iter.is_double_ended(),
            Self::Filter(iter) => iter.is_double_ended(),
            Self::Rev(..) => true,
            Self::Chain(iter) => iter.is_double_ended(),
            Self::Enumerate(iter) => iter.is_double_ended(),
            Self::Skip(iter) => iter.is_double_ended(),
            Self::Take(iter) => iter.is_double_ended(),
            Self::Peekable(iter) => iter.is_double_ended(),
            Self::Empty => true,
            Self::Once(..) => true,
        }
    }
fn is_double_ended ( & self ) -> bool { match self { Self :: Iterator ( .. ) => false , Self :: DoubleEndedIterator ( .. ) => true , Self :: Map ( iter ) => iter . is_double_ended ( ) , Self :: FlatMap ( iter ) => iter . is_double_ended ( ) , Self :: Filter ( iter ) => iter . is_double_ended ( ) , Self :: Rev ( .. ) => true , Self :: Chain ( iter ) => iter . is_double_ended ( ) , Self :: Enumerate ( iter ) => iter . is_double_ended ( ) , Self :: Skip ( iter ) => iter . is_double_ended ( ) , Self :: Take ( iter ) => iter . is_double_ended ( ) , Self :: Peekable ( iter ) => iter . is_double_ended ( ) , Self :: Empty => true , Self :: Once ( .. ) => true , } }
Test if this iterator is double-ended.
Test if this iterator is double - ended .
&self
&self