That's how folly::Synchronized works, it supports both the callback interface as MutexProtected, and an interface that returns a RAII lock holder that gives acc

That's how folly::Synchronized works, it supports both the callback interface as MutexProtected, and an interface that returns a RAII lock holder that gives access to the underlying object. It is generally the preferred synchronization utility at Meta and thus it is widely used. https://github.com/facebook/folly/blob/main/folly/docs/Synchronized.md https://github.com/facebook/folly/blob/main/folly/docs/Synch...