error: using `drain` can result in unstable query results
  --> $DIR/query_stability.rs:13:16
   |
LL |     for _ in x.drain() {}
   |                ^^^^^
   |
   = note: if you believe this case to be fine, allow this lint and add a comment explaining your rationale
note: the lint level is defined here
  --> $DIR/query_stability.rs:4:9
   |
LL | #![deny(rustc::potential_query_instability)]
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: using `iter` can result in unstable query results
  --> $DIR/query_stability.rs:16:16
   |
LL |     for _ in x.iter() {}
   |                ^^^^
   |
   = note: if you believe this case to be fine, allow this lint and add a comment explaining your rationale

error: using `iter_mut` can result in unstable query results
  --> $DIR/query_stability.rs:19:36
   |
LL |     for _ in Some(&mut x).unwrap().iter_mut() {}
   |                                    ^^^^^^^^
   |
   = note: if you believe this case to be fine, allow this lint and add a comment explaining your rationale

error: using `into_iter` can result in unstable query results
  --> $DIR/query_stability.rs:22:14
   |
LL |     for _ in x {}
   |              ^
   |
   = note: if you believe this case to be fine, allow this lint and add a comment explaining your rationale

error: aborting due to 4 previous errors