Isn't the "regions" approach similar/same in principle, as Rust's memory model? A region's model is described as: > Pony's iso keyword: an iso'd object (and i

Isn't the "regions" approach similar/same in principle, as Rust's memory model? A region's model is described as: > Pony's iso keyword: an iso'd object (and its contents) are only reachable from your pointer; nobody else points at that object or anything the object contains [...] we can "temporarily open" an isolated subgraph for a given scope, and afterward it would still be properly isolated. In Rust, AFAIR, one gets a mutable reference to an object, and the borrower can independently operate on its fields (subgraphs), while the root mutable reference can't be accessed from anything else other than the borrower.