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
|
#![feature(type_alias_impl_trait)]
use std::fmt::Display;
type Opaque<X> = impl Sized + 'static;
#[define_opaque(Opaque)]
fn define<X>() -> Opaque<X> {}
trait Trait {
type Assoc: Display;
}
impl<'a> Trait for Opaque<&'a str> {
//~^ ERROR the lifetime parameter `'a` is not constrained by the impl trait, self type, or predicates
type Assoc = &'a str;
}
// ======= Exploit =======
fn extend<T: Trait + 'static>(s: T::Assoc) -> Box<dyn Display> {
Box::new(s)
}
fn main() {
let val = extend::<Opaque<&'_ str>>(&String::from("blah blah blah"));
println!("{}", val);
}
|
