error: usage of an `Arc` that is not `Send` or `Sync` --> $DIR/arc_with_non_send_sync.rs:18:13 | LL | let _ = Arc::new(RefCell::new(42)); | ^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: the trait `Sync` is not implemented for `RefCell<i32>` = note: required for `Arc<RefCell<i32>>` to implement `Send` and `Sync` = help: consider using an `Rc` instead or wrapping the inner type with a `Mutex` = note: `-D clippy::arc-with-non-send-sync` implied by `-D warnings` error: usage of an `Arc` that is not `Send` or `Sync` --> $DIR/arc_with_non_send_sync.rs:21:13 | LL | let _ = Arc::new(mutex.lock().unwrap()); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: the trait `Send` is not implemented for `MutexGuard<'_, i32>` = note: required for `Arc<MutexGuard<'_, i32>>` to implement `Send` and `Sync` = help: consider using an `Rc` instead or wrapping the inner type with a `Mutex` error: usage of an `Arc` that is not `Send` or `Sync` --> $DIR/arc_with_non_send_sync.rs:23:13 | LL | let _ = Arc::new(&42 as *const i32); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: the trait `Send` is not implemented for `*const i32` = note: the trait `Sync` is not implemented for `*const i32` = note: required for `Arc<*const i32>` to implement `Send` and `Sync` = help: consider using an `Rc` instead or wrapping the inner type with a `Mutex` error: aborting due to 3 previous errors