File: issue-21726.rs

package info (click to toggle)
rustc 1.85.0%2Bdfsg3-1
  • links: PTS, VCS
  • area: main
  • in suites: experimental, forky, sid, trixie
  • size: 893,396 kB
  • sloc: xml: 158,127; python: 35,830; javascript: 19,497; cpp: 19,002; sh: 17,245; ansic: 13,127; asm: 4,376; makefile: 1,051; perl: 29; lisp: 29; ruby: 19; sql: 11
file content (37 lines) | stat: -rw-r--r-- 734 bytes parent folder | download | duplicates (4)
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
//@ check-pass
#![allow(dead_code)]
// Regression test for #21726: an issue arose around the rules for
// subtyping of projection types that resulted in an unconstrained
// region, yielding region inference failures.


fn main() { }

fn foo<'a>(s: &'a str) {
    let b: B<()> = B::new(s, ());
    b.get_short();
}

trait IntoRef<'a> {
    type T: Clone;
    fn into_ref(self, _: &'a str) -> Self::T;
}

impl<'a> IntoRef<'a> for () {
    type T = &'a str;
    fn into_ref(self, s: &'a str) -> &'a str {
        s
    }
}

struct B<'a, P: IntoRef<'a>>(P::T);

impl<'a, P: IntoRef<'a>> B<'a, P> {
    fn new(s: &'a str, i: P) -> B<'a, P> {
        B(i.into_ref(s))
    }

    fn get_short(&self) -> P::T {
        self.0.clone()
    }
}