tests/ui/sized/recursive-type-binding.rs

// build-fail
//~^ ERROR cycle detected when computing layout of `Foo<()>`

trait A { type Assoc: ?Sized; }

impl A for () {
    type Assoc = Foo<()>;
}
struct Foo<T: A>(T::Assoc);

fn main() {
    let x: Foo<()>;
}