error[E0277]: the trait bound `(): MyTrait` is not satisfied
  --> $DIR/no-use.rs:10:26
   |
LL | trait MyTrait { fn foo(&self); }
   |                 -------------- required by `MyTrait::foo`
...
LL |     <() as MyTrait>::foo(&());
   |                          ^^^ the trait `MyTrait` is not implemented for `()`
   |
   = help: the following implementations were found:
             <() as MyTrait>

error: aborting due to previous error

For more information about this error, try `rustc --explain E0277`.