1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 fn pairwise_sub<T:DoubleEndedIterator<Item=int>>(mut t: T) -> int {
15 let back = t.next_back();
17 (Some(f), Some(b)) => { result += b - f; }
18 _ => { return result; }
24 let v = vec!(1, 2, 3, 4, 5, 6);
25 let r =pairwise_sub(v.into_iter());