1 // Checks to ensure that we properly detect when a closure constrains an opaque type
3 #![feature(type_alias_impl_trait)]
8 type Opaque = impl Debug;
9 fn _unused() -> Opaque { String::new() }
10 let null = || -> Opaque { 0 };
11 //~^ ERROR: concrete type differs from previous defining opaque type use
12 println!("{:?}", null());