src/test/ui/issue-42106.nll.stderr

   1 error[E0502]: cannot borrow `*collection` as mutable because it is also borrowed as immutable
   2   --> $DIR/issue-42106.rs:13:5
   3    |
   4 LL |     let _a = &collection;
   5    |              ----------- immutable borrow occurs here
   6 LL |     collection.swap(1, 2); //~ ERROR also borrowed as immutable
   7    |     ^^^^^^^^^^ mutable borrow occurs here
   8 LL |     _a.use_ref();
   9    |     -- borrow later used here
  10
  11 error: aborting due to previous error
  12
  13 For more information about this error, try `rustc --explain E0502`.