error: `--x` could be misinterpreted as pre-decrement by C programmers, is usually a no-op
  --> $DIR/double_neg.rs:7:5
   |
LL |     --x;
   |     ^^^
   |
   = note: `-D clippy::double-neg` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(clippy::double_neg)]`

error: aborting due to 1 previous error