#![feature(type_alias_impl_trait)]
type X<'a, 'b> = impl std::fmt::Debug;
fn f<'t, 'u>(a: &'t u32, b: &'u u32) -> (X<'t, 'u>, X<'u, 't>) {
(a, a)
//~^ ERROR concrete type differs from previous defining opaque type use
}
fn main() {}