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
5 | ^^^^^^^ cannot borrow as mutable
7 help: consider changing this to be mutable
9 LL | let mut a: Box<_> = Box::new(A);
12 error: aborting due to previous error
14 For more information about this error, try `rustc --explain E0596`.