blob: 1f3b8ac99b19146f766e6758d0cd799d37dc92c0 (
plain)
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
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
// run-rustfix
#![warn(clippy::len_zero)]
#![allow(dead_code, unused, clippy::len_without_is_empty)]
pub struct One;
struct Wither;
trait TraitsToo {
fn len(&self) -> isize;
// No error; `len` is private; see issue #1085.
}
impl TraitsToo for One {
fn len(&self) -> isize {
0
}
}
pub struct HasIsEmpty;
impl HasIsEmpty {
pub fn len(&self) -> isize {
1
}
fn is_empty(&self) -> bool {
false
}
}
pub struct HasWrongIsEmpty;
impl HasWrongIsEmpty {
pub fn len(&self) -> isize {
1
}
pub fn is_empty(&self, x: u32) -> bool {
false
}
}
pub trait WithIsEmpty {
fn len(&self) -> isize;
fn is_empty(&self) -> bool;
}
impl WithIsEmpty for Wither {
fn len(&self) -> isize {
1
}
fn is_empty(&self) -> bool {
false
}
}
fn main() {
let x = [1, 2];
if x.is_empty() {
println!("This should not happen!");
}
if "".is_empty() {}
let y = One;
if y.len() == 0 {
// No error; `One` does not have `.is_empty()`.
println!("This should not happen either!");
}
let z: &dyn TraitsToo = &y;
if z.len() > 0 {
// No error; `TraitsToo` has no `.is_empty()` method.
println!("Nor should this!");
}
let has_is_empty = HasIsEmpty;
if has_is_empty.is_empty() {
println!("Or this!");
}
if !has_is_empty.is_empty() {
println!("Or this!");
}
if !has_is_empty.is_empty() {
println!("Or this!");
}
if has_is_empty.is_empty() {
println!("Or this!");
}
if !has_is_empty.is_empty() {
println!("Or this!");
}
if has_is_empty.len() > 1 {
// No error.
println!("This can happen.");
}
if has_is_empty.len() <= 1 {
// No error.
println!("This can happen.");
}
if has_is_empty.is_empty() {
println!("Or this!");
}
if !has_is_empty.is_empty() {
println!("Or this!");
}
if !has_is_empty.is_empty() {
println!("Or this!");
}
if !has_is_empty.is_empty() {
println!("Or this!");
}
if has_is_empty.is_empty() {
println!("Or this!");
}
if 1 < has_is_empty.len() {
// No error.
println!("This can happen.");
}
if 1 >= has_is_empty.len() {
// No error.
println!("This can happen.");
}
assert!(!has_is_empty.is_empty());
let with_is_empty: &dyn WithIsEmpty = &Wither;
if with_is_empty.is_empty() {
println!("Or this!");
}
assert!(!with_is_empty.is_empty());
let has_wrong_is_empty = HasWrongIsEmpty;
if has_wrong_is_empty.len() == 0 {
// No error; `HasWrongIsEmpty` does not have `.is_empty()`.
println!("Or this!");
}
}
fn test_slice(b: &[u8]) {
if !b.is_empty() {}
}
|
