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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
|
#![warn(clippy::all)]
#![warn(clippy::redundant_pattern_matching)]
#![allow(
unused_must_use,
clippy::needless_bool,
clippy::needless_if,
clippy::match_like_matches_macro,
clippy::equatable_if_let,
clippy::if_same_then_else
)]
#![feature(let_chains, if_let_guard)]
fn issue_11174<T>(boolean: bool, maybe_some: Option<T>) -> bool {
matches!(maybe_some, None if !boolean)
}
fn issue_11174_edge_cases<T>(boolean: bool, boolean2: bool, maybe_some: Option<T>) {
let _ = matches!(maybe_some, None if boolean || boolean2); // guard needs parentheses
let _ = match maybe_some {
// can't use `matches!` here
// because `expr` metavars in macros don't allow let exprs
None if let Some(x) = Some(0)
&& x > 5 =>
{
true
},
_ => false,
};
}
fn main() {
if let None = None::<()> {}
if let Some(_) = Some(42) {}
if let Some(_) = Some(42) {
foo();
} else {
bar();
}
while let Some(_) = Some(42) {}
while let None = Some(42) {}
while let None = None::<()> {}
let mut v = vec![1, 2, 3];
while let Some(_) = v.pop() {
foo();
}
if None::<i32>.is_none() {}
if Some(42).is_some() {}
match Some(42) {
Some(_) => true,
None => false,
};
match None::<()> {
Some(_) => false,
None => true,
};
let _ = match None::<()> {
Some(_) => false,
None => true,
};
let opt = Some(false);
let _ = if let Some(_) = opt { true } else { false };
issue6067();
issue10726();
issue10803();
let _ = if let Some(_) = gen_opt() {
1
} else if let None = gen_opt() {
2
} else {
3
};
if let Some(..) = gen_opt() {}
}
fn gen_opt() -> Option<()> {
None
}
fn foo() {}
fn bar() {}
// Methods that are unstable const should not be suggested within a const context, see issue #5697.
// However, in Rust 1.48.0 the methods `is_some` and `is_none` of `Option` were stabilized as const,
// so the following should be linted.
const fn issue6067() {
if let Some(_) = Some(42) {}
if let None = None::<()> {}
while let Some(_) = Some(42) {}
while let None = None::<()> {}
match Some(42) {
Some(_) => true,
None => false,
};
match None::<()> {
Some(_) => false,
None => true,
};
}
#[allow(clippy::deref_addrof, dead_code, clippy::needless_borrow)]
fn issue7921() {
if let None = *(&None::<()>) {}
if let None = *&None::<()> {}
}
fn issue10726() {
let x = Some(42);
match x {
Some(_) => true,
_ => false,
};
match x {
None => true,
_ => false,
};
match x {
Some(_) => false,
_ => true,
};
match x {
None => false,
_ => true,
};
// Don't lint
match x {
Some(21) => true,
_ => false,
};
}
fn issue10803() {
let x = Some(42);
let _ = matches!(x, Some(_));
let _ = matches!(x, None);
// Don't lint
let _ = matches!(x, Some(16));
}
|