File: issue-83857-ub.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 (34 lines) | stat: -rw-r--r-- 874 bytes parent folder | download | duplicates (6)
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
// Tests that we don't incorrectly allow overlap between a builtin auto trait
// impl and a user written one. See #83857 for more details

struct Always<T, U>(T, U);
unsafe impl<T, U> Send for Always<T, U> {}
struct Foo<T, U>(Always<T, U>);

trait False {}
unsafe impl<U: False> Send for Foo<u32, U> {}

trait WithAssoc {
    type Output;
}
impl<T: Send> WithAssoc for T {
    type Output = Self;
}
impl WithAssoc for Foo<u32, ()> {
    type Output = Box<i32>;
}

fn generic<T, U>(v: Foo<T, U>, f: fn(<Foo<T, U> as WithAssoc>::Output) -> i32) {
    //~^ ERROR `Foo<T, U>` cannot be sent between threads safely
    //~| ERROR `Foo<T, U>` cannot be sent between threads safely
    f(foo(v));
    //~^ ERROR `Foo<T, U>` cannot be sent between threads safely
}

fn foo<T: Send>(x: T) -> <T as WithAssoc>::Output {
    x
}

fn main() {
    generic(Foo(Always(0, ())), |b| *b);
}