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
|
// Test that we are imposing the requirement that every associated
// type of a bound that appears in the where clause on a struct must
// outlive the location in which the type appears. Issue #22246.
#![allow(dead_code)]
#![feature(rustc_attrs)]
pub trait TheTrait {
type TheAssocType;
}
pub struct TheType<'b> {
m: [fn(&'b()); 0]
}
impl<'b> TheTrait for TheType<'b> {
type TheAssocType = &'b ();
}
pub struct WithAssoc<T:TheTrait> {
m: [T; 0]
}
pub struct WithoutAssoc<T> {
m: [T; 0]
}
fn with_assoc<'a,'b>() {
// For this type to be valid, the rules require that all
// associated types of traits that appear in `WithAssoc` must
// outlive 'a. In this case, that means TheType<'b>::TheAssocType,
// which is &'b (), must outlive 'a.
// FIXME (#54943) NLL doesn't enforce WF condition in unreachable code if
// `_x` is changed to `_`
let _x: &'a WithAssoc<TheType<'b>> = loop { };
//~^ ERROR lifetime may not live long enough
}
fn with_assoc1<'a,'b>() where 'b : 'a {
// For this type to be valid, the rules require that all
// associated types of traits that appear in `WithAssoc` must
// outlive 'a. In this case, that means TheType<'b>::TheAssocType,
// which is &'b (), must outlive 'a, so 'b : 'a must hold, and
// that is in the where clauses, so we're fine.
let _x: &'a WithAssoc<TheType<'b>> = loop { };
}
fn without_assoc<'a,'b>() {
// Here there are no associated types but there is a requirement
// that `'b:'a` holds because the `'b` appears in `TheType<'b>`.
let _x: &'a WithoutAssoc<TheType<'b>> = loop { };
//~^ ERROR lifetime may not live long enough
}
fn call_with_assoc<'a,'b>() {
// As `with_assoc`, but just checking that we impose the same rule
// on the value supplied for the type argument, even when there is
// no data.
call::<&'a WithAssoc<TheType<'b>>>();
//~^ ERROR lifetime may not live long enough
}
fn call_without_assoc<'a,'b>() {
// As `without_assoc`, but in a distinct scenario.
call::<&'a WithoutAssoc<TheType<'b>>>();
//~^ ERROR lifetime may not live long enough
}
fn call<T>() { }
fn main() {
}
|
