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
|
// Test the enum_intrinsics_non_enums lint.
#![feature(variant_count)]
use std::mem::{discriminant, variant_count};
enum SomeEnum {
A,
B,
}
struct SomeStruct;
fn generic_discriminant<T>(v: &T) {
discriminant::<T>(v);
}
fn generic_variant_count<T>() -> usize {
variant_count::<T>()
}
fn test_discriminant() {
discriminant(&SomeEnum::A);
generic_discriminant(&SomeEnum::B);
discriminant(&());
//~^ error: the return value of `mem::discriminant` is unspecified when called with a non-enum type
discriminant(&&SomeEnum::B);
//~^ error: the return value of `mem::discriminant` is unspecified when called with a non-enum type
discriminant(&SomeStruct);
//~^ error: the return value of `mem::discriminant` is unspecified when called with a non-enum type
discriminant(&123u32);
//~^ error: the return value of `mem::discriminant` is unspecified when called with a non-enum type
discriminant(&&123i8);
//~^ error: the return value of `mem::discriminant` is unspecified when called with a non-enum type
}
fn test_variant_count() {
variant_count::<SomeEnum>();
generic_variant_count::<SomeEnum>();
variant_count::<&str>();
//~^ error: the return value of `mem::variant_count` is unspecified when called with a non-enum type
variant_count::<*const u8>();
//~^ error: the return value of `mem::variant_count` is unspecified when called with a non-enum type
variant_count::<()>();
//~^ error: the return value of `mem::variant_count` is unspecified when called with a non-enum type
variant_count::<&SomeEnum>();
//~^ error: the return value of `mem::variant_count` is unspecified when called with a non-enum type
}
fn main() {
test_discriminant();
test_variant_count();
// The lint ignores cases where the type is generic, so these should be
// allowed even though their return values are unspecified
generic_variant_count::<SomeStruct>();
generic_discriminant::<SomeStruct>(&SomeStruct);
}
|
