error[E0499]: cannot borrow `my_struct.field` as mutable more than once at a time (Ast)
  --> $DIR/return_from_loop.rs:32:9
   |
LL |     let value = &mut my_struct.field;
   |                      --------------- first mutable borrow occurs here
LL |     loop {
LL |         my_struct.field.push_str("Hello, world!");
   |         ^^^^^^^^^^^^^^^ second mutable borrow occurs here
...
LL | }
   | - first borrow ends here

error[E0499]: cannot borrow `my_struct.field` as mutable more than once at a time (Ast)
  --> $DIR/return_from_loop.rs:45:9
   |
LL |     let value = &mut my_struct.field;
   |                      --------------- first mutable borrow occurs here
LL |     loop {
LL |         my_struct.field.push_str("Hello, world!");
   |         ^^^^^^^^^^^^^^^ second mutable borrow occurs here
...
LL | }
   | - first borrow ends here

error[E0499]: cannot borrow `my_struct.field` as mutable more than once at a time (Mir)
  --> $DIR/return_from_loop.rs:32:9
   |
LL |     let value = &mut my_struct.field;
   |                 -------------------- first mutable borrow occurs here
LL |     loop {
LL |         my_struct.field.push_str("Hello, world!");
   |         ^^^^^^^^^^^^^^^ second mutable borrow occurs here
...
LL |         value.len();
   |         ----- first borrow later used here

error: aborting due to 3 previous errors

For more information about this error, try `rustc --explain E0499`.