error[E0389]: cannot borrow data mutably in a `&` reference
--> $DIR/issue-38147-4.rs:16:5
|
15 | fn f(x: usize, f: &Foo) {
| ---- use `&mut Foo` here to make mutable
16 | f.s.push('x');
| ^^^ assignment into an immutable reference
error: aborting due to previous error(s)