blob: 7d2cad978fc02ef96e654f2d1a7bb9dfb0e2145b (
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
|
// run-pass
// adapted from src/test/ui/binding/if-let.rs
#![allow(dead_code)]
fn none() -> bool {
let None = Some("test") else {
return true;
};
false
}
fn ok() -> bool {
let Ok(()) = Err::<(),&'static str>("test") else {
return true;
};
false
}
pub fn main() {
let x = Some(3);
let Some(y) = x else {
panic!("let-else panicked");
};
assert_eq!(y, 3);
let Some(_) = x else {
panic!("bad match");
};
assert!(none());
assert!(ok());
assert!((|| {
let 1 = 2 else {
return true;
};
false
})());
enum Foo {
One,
Two(usize),
Three(String, isize),
}
let foo = Foo::Three("three".to_string(), 42);
let one = || {
let Foo::One = foo else {
return true;
};
false
};
assert!(one());
let two = || {
let Foo::Two(_x) = foo else {
return true;
};
false
};
assert!(two());
let three = || {
let Foo::Three(s, _x) = foo else {
return false;
};
s == "three"
};
assert!(three());
let a@Foo::Two(_) = Foo::Two(42_usize) else {
panic!("bad match")
};
let Foo::Two(b) = a else {
panic!("panic in nested `if let`");
};
assert_eq!(b, 42_usize);
}
|
