error[E0308]: mismatched types
  --> $DIR/issue-56943.rs:6:29
   |
LL |     let _: issue_56943::S = issue_56943::S2;
   |            --------------   ^^^^^^^^^^^^^^^ expected struct `issue_56943::S`, found struct `issue_56943::S2`
   |            |
   |            expected due to this

error: aborting due to previous error

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