1 error[E0596]: cannot borrow `*f.s` as mutable, as it is behind a `&` reference
2 --> $DIR/issue-38147-4.rs:6:5
5 | ^^^^^^^^^^^^^ `f` is a `&` reference, so the data it refers to cannot be borrowed as mutable
7 help: consider changing this to be a mutable reference
9 LL | fn f(x: usize, f: &mut Foo<'_>) {
12 error: aborting due to previous error
14 For more information about this error, try `rustc --explain E0596`.