1 // Copyright 2015 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.
12 use std::cmp::{self, PartialOrd, Ordering};
14 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
20 impl PartialOrd for Foo {
21 fn partial_cmp(&self, other: &Foo) -> Option<Ordering> {
27 fn cmp(&self, other: &Foo) -> Ordering {
33 let a = Foo { n: 4, name: "a" };
34 let b = Foo { n: 4, name: "b" };
35 let c = Foo { n: 8, name: "c" };
36 let d = Foo { n: 8, name: "d" };
37 let e = Foo { n: 22, name: "e" };
38 let f = Foo { n: 22, name: "f" };
40 let data = [a, b, c, d, e, f];
42 // `min` should return the left when the values are equal
43 assert_eq!(data.iter().min(), Some(&a));
44 assert_eq!(data.iter().min_by_key(|a| a.n), Some(&a));
45 assert_eq!(cmp::min(a, b), a);
46 assert_eq!(cmp::min(b, a), b);
48 // `max` should return the right when the values are equal
49 assert_eq!(data.iter().max(), Some(&f));
50 assert_eq!(data.iter().max_by_key(|a| a.n), Some(&f));
51 assert_eq!(cmp::max(e, f), f);
52 assert_eq!(cmp::max(f, e), e);
54 let mut presorted = data.to_vec();
56 assert_stable(&presorted);
58 let mut presorted = data.to_vec();
59 presorted.sort_by(|a, b| a.cmp(b));
60 assert_stable(&presorted);
62 // Assert that sorted and min/max are the same
63 fn assert_stable<T: Ord + Debug>(presorted: &[T]) {
64 for slice in presorted.windows(2) {
68 assert_eq!(a, cmp::min(a, b));
69 assert_eq!(b, cmp::max(a, b));