Here’s what I understand from your comment, correct me if I’m wrong. You’re saying there is a runtime cost associated with a mutex/rwlock owning the data. And s

Here’s what I understand from your comment, correct me if I’m wrong. You’re saying there is a runtime cost associated with a mutex/rwlock owning the data. And secondly, you think it isn’t possible to implement this pattern in other areas that need locking. I don’t think either of those is true. Encoding the ownership in the type system makes things clearer, imposes a compile-time cost but not run-time cost. Also, there isn’t any magic in the stdlib implementation of Mutex and Rwlock other than implementing it natively for every OS. This means that it is possible to implement the pattern for the examples you gave.