#![stable(feature = "rust1", since = "1.0.0")]
-use clone::Clone;
use cmp;
-use default::Default;
use fmt;
use iter_private::TrustedRandomAccess;
-use ops::FnMut;
-use option::Option::{self, Some, None};
use usize;
#[stable(feature = "rust1", since = "1.0.0")]