Data races in reffers
ARefss<'a, V> is a type that is assumed to contain objects that are Send + Sync. In the affected versions of this crate, Send/Sync traits are unconditionally implemented for ARefss<'a, V>. By using the ARefss::map() API, we can insert a !Send or !Sync object into ARefss<'a, V>. After that, it is possible to create a data race to the inner object of ARefss<'a, V>, which can lead to undefined behavior …