rust/tests/ui/traits/trait-upcasting/alias-where-clause-isnt-supertrait.rs
Urgau 4c2d6de70e Stabilize RFC3324 dyn upcasting coercion
Aka trait_upcasting feature.

And also adjust the `deref_into_dyn_supertrait` lint.
2023-11-22 13:56:36 +01:00

33 lines
459 B
Rust

#![feature(trait_alias)]
// Although we *elaborate* `T: Alias` to `i32: B`, we should
// not consider `B` to be a supertrait of the type.
trait Alias = A where i32: B;
trait A {}
trait B {
fn test(&self);
}
trait C: Alias {}
impl A for () {}
impl C for () {}
impl B for i32 {
fn test(&self) {
println!("hi {self}");
}
}
fn test(x: &dyn C) -> &dyn B {
x
//~^ ERROR mismatched types
}
fn main() {
let x: &dyn C = &();
}