1 // https://github.com/rust-lang/rust/issues/73481
2 // This test used to cause unsoundness, since one of the two possible
3 // resolutions was chosen at random instead of erroring due to conflicts.
5 #![feature(type_alias_impl_trait)]
7 type X<A: ToString + Clone, B: ToString + Clone> = impl ToString;
9 fn f<A: ToString + Clone, B: ToString + Clone>(a: A, b: B) -> (X<A, B>, X<B, A>) {
11 //~^ ERROR concrete type differs from previous defining opaque type
15 println!("{}", <X<_, _> as ToString>::to_string(&f(42_i32, String::new()).1));