| error[E0502]: cannot borrow `*collection` as mutable because it is also borrowed as immutable | |
| --> $DIR/issue-42106.rs:3:5 | |
| | | |
| LL | let _a = &collection; | |
| | ----------- immutable borrow occurs here | |
| LL | collection.swap(1, 2); | |
| | ^^^^^^^^^^ mutable borrow occurs here | |
| LL | _a.use_ref(); | |
| | -- immutable borrow later used here | |
| error: aborting due to 1 previous error | |
| For more information about this error, try `rustc --explain E0502`. |