error[E0389]: cannot borrow data mutably in a `&` reference
--> $DIR/issue-38147-1.rs:27:9
|
LL | fn f(&self) {
| ----- use `&mut self` here to make mutable
LL | self.s.push('x'); //~ ERROR cannot borrow data mutably
| ^^^^^^ assignment into an immutable reference
error: aborting due to previous error
For more information about this error, try `rustc --explain E0389`.