error[E0596]: cannot borrow `self` as mutable, as it is not declared as mutable
  --> $DIR/issue-51191.rs:17:9
   |
LL |         (&mut self).bar();
   |         ^^^^^^^^^^^
   |         |
   |         cannot borrow as mutable
   |         try removing `&mut` here

error[E0596]: cannot borrow `self` as mutable, as it is not declared as mutable
  --> $DIR/issue-51191.rs:22:9
   |
LL |     fn imm(self) {
   |            ---- help: consider changing this to be mutable: `mut self`
LL |         (&mut self).bar();
   |         ^^^^^^^^^^^ cannot borrow as mutable

error[E0596]: cannot borrow `self` as mutable, as it is not declared as mutable
  --> $DIR/issue-51191.rs:31:9
   |
LL |         (&mut self).bar();
   |         ^^^^^^^^^^^ cannot borrow as mutable

error[E0596]: cannot borrow data in a `&` reference as mutable
  --> $DIR/issue-51191.rs:31:9
   |
LL |         (&mut self).bar();
   |         ^^^^^^^^^^^ cannot borrow as mutable

error[E0596]: cannot borrow `self` as mutable, as it is not declared as mutable
  --> $DIR/issue-51191.rs:37:9
   |
LL |         (&mut self).bar();
   |         ^^^^^^^^^^^
   |         |
   |         cannot borrow as mutable
   |         try removing `&mut` here

error: aborting due to 5 previous errors

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