Clojure has transient mutable collections that are designed to become persistent once "complete". [1] Some systems have made use of using reference count of one

Clojure has transient mutable collections that are designed to become persistent once "complete". [1] Some systems have made use of using reference count of one (unique owner) as permission to mutate, something that TFA generalizes as memory reuse. 1: https://clojure.org/reference/transients https://clojure.org/reference/transients