error: the `Self` constructor can only be used with tuple or unit structs
  --> $DIR/issue-56199.rs:6:17
   |
LL |         let _ = Self;
   |                 ^^^^
   |
   = help: did you mean to use one of the enum's variants?

error: the `Self` constructor can only be used with tuple or unit structs
  --> $DIR/issue-56199.rs:8:17
   |
LL |         let _ = Self();
   |                 ^^^^^^
   |
   = help: did you mean to use one of the enum's variants?

error: the `Self` constructor can only be used with tuple or unit structs
  --> $DIR/issue-56199.rs:15:17
   |
LL |         let _ = Self;
   |                 ^^^^ help: use curly brackets: `Self { /* fields */ }`

error: the `Self` constructor can only be used with tuple or unit structs
  --> $DIR/issue-56199.rs:17:17
   |
LL |         let _ = Self();
   |                 ^^^^^^ help: use curly brackets: `Self { /* fields */ }`

error: aborting due to 4 previous errors