error[E0499]: cannot borrow `list[_].value` as mutable more than once at a time
  --> $DIR/issue-62007-assign-const-index.rs:23:21
   |
LL | fn to_refs<T>(mut list: [&mut List<T>; 2]) -> Vec<&mut T> {
   |                          - let's call the lifetime of this reference `'1`
...
LL |         result.push(&mut list[0].value);
   |                     ^^^^^^^^^^^^^^^^^^ mutable borrow starts here in previous iteration of loop
...
LL |             return result;
   |                    ------ returning this value requires that `list[_].value` is borrowed for `'1`

error[E0499]: cannot borrow `list[_].next` as mutable more than once at a time
  --> $DIR/issue-62007-assign-const-index.rs:24:26
   |
LL | fn to_refs<T>(mut list: [&mut List<T>; 2]) -> Vec<&mut T> {
   |                          - let's call the lifetime of this reference `'1`
...
LL |         if let Some(n) = list[0].next.as_mut() {
   |                          ^^^^^^^^^^^^---------
   |                          |
   |                          mutable borrow starts here in previous iteration of loop
   |                          argument requires that `list[_].next` is borrowed for `'1`

error: aborting due to 2 previous errors

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