1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
|
// run-rustfix
#![allow(clippy::stable_sort_primitive)]
use std::cell::Ref;
fn unnecessary_sort_by() {
fn id(x: isize) -> isize {
x
}
let mut vec: Vec<isize> = vec![3, 6, 1, 2, 5];
// Forward examples
vec.sort_by(|a, b| a.cmp(b));
vec.sort_unstable_by(|a, b| a.cmp(b));
vec.sort_by(|a, b| (a + 5).abs().cmp(&(b + 5).abs()));
vec.sort_unstable_by(|a, b| id(-a).cmp(&id(-b)));
// Reverse examples
vec.sort_by(|a, b| b.cmp(a)); // not linted to avoid suggesting `Reverse(b)` which would borrow
vec.sort_by(|a, b| (b + 5).abs().cmp(&(a + 5).abs()));
vec.sort_unstable_by(|a, b| id(-b).cmp(&id(-a)));
// Negative examples (shouldn't be changed)
let c = &7;
vec.sort_by(|a, b| (b - a).cmp(&(a - b)));
vec.sort_by(|_, b| b.cmp(&5));
vec.sort_by(|_, b| b.cmp(c));
vec.sort_unstable_by(|a, _| a.cmp(c));
// Vectors of references are fine as long as the resulting key does not borrow
let mut vec: Vec<&&&isize> = vec![&&&3, &&&6, &&&1, &&&2, &&&5];
vec.sort_by(|a, b| (***a).abs().cmp(&(***b).abs()));
vec.sort_unstable_by(|a, b| (***a).abs().cmp(&(***b).abs()));
// `Reverse(b)` would borrow in the following cases, don't lint
vec.sort_by(|a, b| b.cmp(a));
vec.sort_unstable_by(|a, b| b.cmp(a));
// No warning if element does not implement `Ord`
let mut vec: Vec<Ref<usize>> = Vec::new();
vec.sort_unstable_by(|a, b| a.cmp(b));
}
// Do not suggest returning a reference to the closure parameter of `Vec::sort_by_key`
mod issue_5754 {
#[derive(Clone, Copy)]
struct Test(usize);
#[derive(PartialOrd, Ord, PartialEq, Eq)]
struct Wrapper<'a>(&'a usize);
impl Test {
fn name(&self) -> &usize {
&self.0
}
fn wrapped(&self) -> Wrapper<'_> {
Wrapper(&self.0)
}
}
pub fn test() {
let mut args: Vec<Test> = vec![];
// Forward
args.sort_by(|a, b| a.name().cmp(b.name()));
args.sort_by(|a, b| a.wrapped().cmp(&b.wrapped()));
args.sort_unstable_by(|a, b| a.name().cmp(b.name()));
args.sort_unstable_by(|a, b| a.wrapped().cmp(&b.wrapped()));
// Reverse
args.sort_by(|a, b| b.name().cmp(a.name()));
args.sort_by(|a, b| b.wrapped().cmp(&a.wrapped()));
args.sort_unstable_by(|a, b| b.name().cmp(a.name()));
args.sort_unstable_by(|a, b| b.wrapped().cmp(&a.wrapped()));
}
}
// The closure parameter is not dereferenced anymore, so non-Copy types can be linted
mod issue_6001 {
struct Test(String);
impl Test {
// Return an owned type so that we don't hit the fix for 5754
fn name(&self) -> String {
self.0.clone()
}
}
pub fn test() {
let mut args: Vec<Test> = vec![];
// Forward
args.sort_by(|a, b| a.name().cmp(&b.name()));
args.sort_unstable_by(|a, b| a.name().cmp(&b.name()));
// Reverse
args.sort_by(|a, b| b.name().cmp(&a.name()));
args.sort_unstable_by(|a, b| b.name().cmp(&a.name()));
}
}
fn main() {
unnecessary_sort_by();
issue_5754::test();
issue_6001::test();
}
|
