| // Copyright 2012 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| |
| trait sum { |
| fn sum_(self) -> isize; |
| } |
| |
| // Note: impl on a slice |
| impl<'a> sum for &'a [isize] { |
| fn sum_(self) -> isize { |
| self.iter().fold(0, |a, &b| a + b) |
| } |
| } |
| |
| fn call_sum(x: &[isize]) -> isize { x.sum_() } |
| |
| pub fn main() { |
| let x = vec!(1, 2, 3); |
| let y = call_sum(&x); |
| println!("y=={}", y); |
| assert_eq!(y, 6); |
| |
| let x = vec!(1, 2, 3); |
| let y = x.sum_(); |
| println!("y=={}", y); |
| assert_eq!(y, 6); |
| |
| let x = vec!(1, 2, 3); |
| let y = x.sum_(); |
| println!("y=={}", y); |
| assert_eq!(y, 6); |
| } |