src/test/ui/traits/wf-trait-object-only-maybe-bound.rs

// Test that `dyn ?Sized` (i.e., a trait object with only a maybe buond) is not allowed.

type _0 = dyn ?Sized;
//~^ ERROR at least one trait is required for an object type [E0224]
//~| ERROR ?Trait` is not permitted in trait object types

fn main() {}