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