error[E0308]: mismatched types
  --> $DIR/const.rs:14:9
   |
LL |         FOO => {}, //~ ERROR mismatched types
   |         ^^^ expected &Foo, found struct `Foo`
   |
   = note: expected type `&Foo`
              found type `Foo`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0308`.