File: typeck-unsafe-always-share.rs

package info (click to toggle)
rustc-web 1.70.0%2Bdfsg1-7~deb11u1
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 1,517,036 kB
  • sloc: xml: 147,962; javascript: 10,210; sh: 8,590; python: 8,220; ansic: 5,901; cpp: 4,635; makefile: 4,006; asm: 2,856
file content (32 lines) | stat: -rw-r--r-- 797 bytes parent folder | download | duplicates (24)
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
// Verify that UnsafeCell is *always* !Sync regardless if `T` is sync.

#![feature(negative_impls)]

use std::cell::UnsafeCell;
use std::marker::Sync;

struct MySync<T> {
    u: UnsafeCell<T>
}

struct NoSync;
impl !Sync for NoSync {}

fn test<T: Sync>(s: T) {}

fn main() {
    let us = UnsafeCell::new(MySync{u: UnsafeCell::new(0)});
    test(us);
    //~^ ERROR `UnsafeCell<MySync<{integer}>>` cannot be shared between threads safely

    let uns = UnsafeCell::new(NoSync);
    test(uns);
    //~^ ERROR `UnsafeCell<NoSync>` cannot be shared between threads safely [E0277]

    let ms = MySync{u: uns};
    test(ms);
    //~^ ERROR `UnsafeCell<NoSync>` cannot be shared between threads safely [E0277]

    test(NoSync);
    //~^ ERROR `NoSync` cannot be shared between threads safely [E0277]
}