tests/ui/impl-trait/in-trait/opaque-and-lifetime-mismatch.rs

struct Wrapper<'rom>(&'rom ());

trait Foo {
    fn bar() -> Wrapper<impl Sized>;
    //~^ ERROR missing lifetime specifier
    //~| ERROR struct takes 0 generic arguments but 1 generic argument was supplied
}

impl Foo for () {
    fn bar() -> i32 {
        0
    }
}

trait Bar {
    fn foo() -> Wrapper<impl Sized>;
    //~^ ERROR missing lifetime specifier
    //~| ERROR struct takes 0 generic arguments but 1 generic argument was supplied
}

impl Bar for () {
    fn foo() -> Wrapper<impl Sized> {
        //~^ ERROR missing lifetime specifier
        //~| ERROR struct takes 0 generic arguments but 1 generic argument was supplied
        Wrapper(&())
    }
}

fn main() {}