src/test/run-pass/associated-types-iterator-binding.rs

   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.
   4 //
   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.
  10
  11
  12 fn pairwise_sub<T:DoubleEndedIterator<Item=isize>>(mut t: T) -> isize {
  13     let mut result = 0;
  14     loop {
  15         let front = t.next();
  16         let back = t.next_back();
  17         match (front, back) {
  18             (Some(f), Some(b)) => { result += b - f; }
  19             _ => { return result; }
  20         }
  21     }
  22 }
  23
  24 fn main() {
  25     let v = vec![1, 2, 3, 4, 5, 6];
  26     let r = pairwise_sub(v.into_iter());
  27     assert_eq!(r, 9);
  28 }