File: issue_41697.rs

package info (click to toggle)
rustc-web 1.78.0%2Bdfsg1-2~deb11u3
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 1,245,360 kB
  • sloc: xml: 147,985; javascript: 18,022; sh: 11,083; python: 10,265; ansic: 6,172; cpp: 5,023; asm: 4,390; makefile: 4,269
file content (41 lines) | stat: -rw-r--r-- 1,088 bytes parent folder | download
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
// skip-filecheck
// Regression test for #41697. Using dump-mir was triggering
// artificial cycles: during type-checking, we had to get the MIR for
// the constant expressions in `[u8; 2]`, which in turn would trigger
// an attempt to get the def-path, which in turn would request the
// types of the impl, which would trigger a cycle. We suppressed this
// cycle now by forcing mir-dump to avoid asking for types of an impl.

#![feature(rustc_attrs)]

use std::sync::Arc;

trait Foo {
    fn get(&self) -> [u8; 2];
}


// EMIT_MIR issue_41697.{impl#0}-{constant#0}.SimplifyCfg-promote-consts.after.mir
impl Foo for [u8; 1+1] {
    fn get(&self) -> [u8; 2] {
        *self
    }
}

struct Bar<T: ?Sized>(T);

fn unsize_fat_ptr<'a>(x: &'a Bar<Foo + Send + 'a>) -> &'a Bar<Foo + 'a> {
    x
}

fn unsize_nested_fat_ptr(x: Arc<Foo + Send>) -> Arc<Foo> {
    x
}

fn main() {
    let x: Box<Bar<Foo + Send>> = Box::new(Bar([1,2]));
    assert_eq!(unsize_fat_ptr(&*x).0.get(), [1, 2]);

    let x: Arc<Foo + Send> = Arc::new([3, 4]);
    assert_eq!(unsize_nested_fat_ptr(x).get(), [3, 4]);
}