| // Copyright 2013 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. |
| |
| // check that the derived impls for the comparison traits shortcircuit |
| // where possible, by having a type that panics when compared as the |
| // second element, so this passes iff the instances shortcircuit. |
| |
| |
| use std::cmp::Ordering; |
| |
| pub struct FailCmp; |
| impl PartialEq for FailCmp { |
| fn eq(&self, _: &FailCmp) -> bool { panic!("eq") } |
| } |
| |
| impl PartialOrd for FailCmp { |
| fn partial_cmp(&self, _: &FailCmp) -> Option<Ordering> { panic!("partial_cmp") } |
| } |
| |
| impl Eq for FailCmp {} |
| |
| impl Ord for FailCmp { |
| fn cmp(&self, _: &FailCmp) -> Ordering { panic!("cmp") } |
| } |
| |
| #[derive(PartialEq,PartialOrd,Eq,Ord)] |
| struct ShortCircuit { |
| x: isize, |
| y: FailCmp |
| } |
| |
| pub fn main() { |
| let a = ShortCircuit { x: 1, y: FailCmp }; |
| let b = ShortCircuit { x: 2, y: FailCmp }; |
| |
| assert!(a != b); |
| assert!(a < b); |
| assert_eq!(a.cmp(&b), ::std::cmp::Ordering::Less); |
| } |