error[E0502]: cannot borrow `v` as mutable because it is also borrowed as immutable
  --> $DIR/issue-82462.rs:18:9
   |
LL |     for x in DroppingSlice(&*v).iter() {
   |              ------------------
   |              |               |
   |              |               immutable borrow occurs here
   |              a temporary with access to the immutable borrow is created here ...
LL |         v.push(*x);
   |         ^^^^^^^^^^ mutable borrow occurs here
LL |         break;
LL |     }
   |     - ... and the immutable borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `DroppingSlice`
   |
help: consider adding semicolon after the expression so its temporaries are dropped sooner, before the local variables declared by the block are dropped
   |
LL |     };
   |      +

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0502`.