tests/ui/borrowck/borrowck-borrow-immut-deref-of-box-as-mut.stderr

   1 error[E0596]: cannot borrow `*a` as mutable, as `a` is not declared as mutable
   2   --> $DIR/borrowck-borrow-immut-deref-of-box-as-mut.rs:12:5
   3    |
   4 LL |     a.foo();
   5    |     ^^^^^^^ cannot borrow as mutable
   6    |
   7 help: consider changing this to be mutable
   8    |
   9 LL |     let mut a: Box<_> = Box::new(A);
  10    |         +++
  11
  12 error: aborting due to previous error
  13
  14 For more information about this error, try `rustc --explain E0596`.