error[E0049]: method `bar` has 1 type parameter but its trait declaration has 0 type parameters
  --> $DIR/generics-mismatch.rs:8:12
   |
LL |     fn bar(&self) -> impl Sized;
   |           - expected 0 type parameters
...
LL |     fn bar<T>(&self) {}
   |            ^ found 1 type parameter

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0049`.