37 lines
591 B
Rust
37 lines
591 B
Rust
|
//@ known-bug: #136666
|
||
|
|
// Needed so that rust can infer that the A in what() is &()
|
||
|
|
trait IsRef<T> {}
|
||
|
|
struct Dummy;
|
||
|
|
impl<'a> IsRef<&'a ()> for Dummy {}
|
||
|
|
|
||
|
|
trait WithLifetime {
|
||
|
|
type Output<'a>;
|
||
|
|
}
|
||
|
|
impl<'t> WithLifetime for &'t () {
|
||
|
|
type Output<'a> = &'a ();
|
||
|
|
}
|
||
|
|
|
||
|
|
// Needed to prevent the two Foo impls from overlapping
|
||
|
|
struct Wrap<A>(A);
|
||
|
|
|
||
|
|
trait Unimplemented {}
|
||
|
|
|
||
|
|
trait Foo {}
|
||
|
|
impl<T> Foo for T where T: Unimplemented {}
|
||
|
|
impl<A> Foo for Wrap<A>
|
||
|
|
where
|
||
|
|
Dummy: IsRef<A>,
|
||
|
|
for<'a> A: WithLifetime<Output<'a> = A>,
|
||
|
|
{
|
||
|
|
}
|
||
|
|
|
||
|
|
fn what<A>()
|
||
|
|
where
|
||
|
|
Wrap<A>: Foo,
|
||
|
|
{
|
||
|
|
}
|
||
|
|
|
||
|
|
fn main() {
|
||
|
|
what();
|
||
|
|
}
|