error[E0308]: match arms have incompatible types
  --> $DIR/wf-unsafe-trait-obj-match.rs:23:17
   |
LL | /     match opt() {
LL | |         Some(()) => &S,
   | |                     -- this is found to be of type `&S`
LL | |         None => &R,
   | |                 ^^ expected struct `S`, found struct `R`
LL | |     }
   | |_____- `match` arms have incompatible types
   |
   = note:   expected type `&S`
           found reference `&R`

error[E0038]: the trait `Trait` cannot be made into an object
  --> $DIR/wf-unsafe-trait-obj-match.rs:26:21
   |
LL |         Some(()) => &S,
   |                     ^^ the trait `Trait` cannot be made into an object
   |
   = note: the trait cannot require that `Self : Sized`
   = note: required because of the requirements on the impl of `std::ops::CoerceUnsized<&dyn Trait>` for `&S`
   = note: required by cast to type `&dyn Trait`

error[E0038]: the trait `Trait` cannot be made into an object
  --> $DIR/wf-unsafe-trait-obj-match.rs:25:25
   |
LL |     let t: &dyn Trait = match opt() {
   |                         ^^^^^^^^^^^ the trait `Trait` cannot be made into an object
   |
   = note: the trait cannot require that `Self : Sized`
   = note: required because of the requirements on the impl of `std::ops::CoerceUnsized<&dyn Trait>` for `&R`
   = note: required by cast to type `&dyn Trait`

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0038, E0308.
For more information about an error, try `rustc --explain E0038`.