use cmp::{PartialEq, Eq, PartialOrd, Ord, Ordering};
use hash;
use io::Writer;
-use iter::{AdditiveIterator, DoubleEndedIteratorExt, Extend};
+use iter::{AdditiveIterator, Extend};
use iter::{Iterator, IteratorExt, Map, repeat};
use mem;
use option::Option;
use super::*;
use clone::Clone;
- use iter::{IteratorExt, DoubleEndedIteratorExt};
+ use iter::IteratorExt;
use option::Option::{mod, Some, None};
use path::GenericPath;
use slice::{AsSlice, SliceExt};