AtomicBox<T> lacks bound on its Send and Sync traits allowing data races

AtomicBox is a Box type designed to be used across threads, however, it implements the Send and Sync traits for all types T. This allows non-Send types such as Rc and non-Sync types such as Cell to be used across thread boundaries which can trigger undefined behavior and memory corruption...

AtomicBox<T> implements Send/Sync for any `T: Sized`

Affected versions of this crate implements Send/Sync for AtomicBox without requiring T: Send/T: Sync. This allows to create data races to T: !Sync and send T: !Send to another thread. Such behavior breaks the compile-time thread safety guarantees of Rust, and allows users to incur undefined...