error[E0369]: no implementation for `String ^ String`
  --> $DIR/binop-bitxor-str.rs:3:37
   |
LL | fn main() { let x = "a".to_string() ^ "b".to_string(); }
   |                     --------------- ^ --------------- String
   |                     |
   |                     String

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0369`.