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
|
// Regression test for issue #57642
// Tests that we reject a bad higher-ranked subtype
trait X {
type G;
fn make_g() -> Self::G;
}
impl<'a> X for fn(&'a ()) {
type G = &'a ();
fn make_g() -> Self::G {
&()
}
}
trait Y {
type F;
fn make_f() -> Self::F;
}
impl<T> Y for fn(T) {
type F = fn(T);
fn make_f() -> Self::F {
|_| {}
}
}
fn higher_ranked_region_has_lost_its_binder() {
let x = <fn (&())>::make_g(); //~ ERROR the function
}
fn magical() {
let x = <fn (&())>::make_f(); //~ ERROR no function
}
fn main() {}
|
