error[E0277]: the trait bound `(): Add` is not satisfied
--> $DIR/associated-types-ICE-when-projecting-out-of-err.rs:23:11
|
LL | r = r + a;
| ^ the trait `Add` is not implemented for `()`
error: aborting due to previous error
For more information about this error, try `rustc --explain E0277`.