File: fallback-closure-wrap.rs

package info (click to toggle)
rustc-web 1.78.0%2Bdfsg1-2~deb12u3
  • links: PTS, VCS
  • area: main
  • in suites: bookworm
  • size: 1,245,420 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 (30 lines) | stat: -rw-r--r-- 916 bytes parent folder | download | duplicates (5)
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
// This is a minified example from Crater breakage observed when attempting to
// stabilize never type, nstoddard/webgl-gui @ 22f0169f.
//
// This particular test case currently fails as the inference to `()` rather
// than `!` happens as a result of an `as` cast, which is not currently tracked.
// Crater did not find many cases of this occurring, but it is included for
// awareness.
//
//@ revisions: nofallback fallback
//@[nofallback] check-pass
//@[fallback] check-fail

#![cfg_attr(fallback, feature(never_type_fallback))]

use std::marker::PhantomData;

fn main() {
    let error = Closure::wrap(Box::new(move || {
        //[fallback]~^ to be a closure that returns `()`, but it returns `!`
        panic!("Can't connect to server.");
    }) as Box<dyn FnMut()>);
}

struct Closure<T: ?Sized>(PhantomData<T>);

impl<T: ?Sized> Closure<T> {
    fn wrap(data: Box<T>) -> Closure<T> {
        todo!()
    }
}