src/test/ui/mut/mut-cross-borrowing.stderr

error[E0308]: mismatched types
  --> $DIR/mut-cross-borrowing.rs:17:7
   |
LL |     f(x)    //~ ERROR mismatched types
   |       ^
   |       |
   |       expected &mut isize, found struct `std::boxed::Box`
   |       help: consider mutably borrowing here: `&mut x`
   |
   = note: expected type `&mut isize`
              found type `std::boxed::Box<{integer}>`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0308`.