File: dont-propagate-generic-instance.rs

package info (click to toggle)
rustc 1.85.0%2Bdfsg3-1
  • links: PTS, VCS
  • area: main
  • in suites: experimental, 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 (24 lines) | stat: -rw-r--r-- 601 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
//@ run-pass

// Makes sure we don't propagate generic instances of `Self: ?Sized` blanket impls.
// This is relevant when we have an overlapping impl and builtin dyn instance.
// See <https://github.com/rust-lang/rust/pull/114941> for more context.

trait Trait {
    fn foo(&self) -> &'static str;
}

impl<T: ?Sized> Trait for T {
    fn foo(&self) -> &'static str {
        std::any::type_name::<T>()
    }
}

const fn bar<T: ?Sized>() -> fn(&T) -> &'static str {
    Trait::foo
    // If const prop were to propagate the instance
}

fn main() {
    assert_eq!("i32", bar::<dyn Trait>()(&1i32));
}