error[E0277]: the size for values of type `str` cannot be known at compilation time
  --> $DIR/open-drop-error2.rs:12:15
   |
LL | fn wrong() -> impl Sized {
   |               ^^^^^^^^^^ doesn't have a size known at compile-time
LL |
LL |     *"abc" // Doesn't implement Sized
   |     ------ return type was inferred to be `str` here
   |
   = help: the trait `Sized` is not implemented for `str`
help: references are always `Sized`, even if they point to unsized data; consider not dereferencing the expression
   |
LL -     *"abc" // Doesn't implement Sized
LL +     "abc" // Doesn't implement Sized
   |

error: aborting due to 1 previous error

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