error[E0596]: cannot borrow immutable borrowed content `*x` as mutable
  --> $DIR/borrowck-call-method-from-mut-aliasable.rs:17:5
   |
LL | fn b(x: &Foo) {
   |         ---- use `&mut Foo` here to make mutable
LL |     x.f();
LL |     x.h();
   |     ^ cannot borrow as mutable

error: aborting due to previous error

For more information about this error, try `rustc --explain E0596`.