DIP1000: The return of 'Extend Return Scope Semantics'

[Ola Fosheim Grøstad]

On Saturday, 12 June 2021 at 18:35:02 UTC, Dennis wrote:
> If you give public access to the `Node* next` member, then you 
> can freely escape `node.next.next` indeed. If you encapsulate 
> it and only allow accessing nodes through `return scope` member 
> functions, then you can make a fully `scope` linked list with 
> e.g. all the nodes allocated on the stack.

There should be some way for an ADT to state that objects they 
produce have the same lifetime as themselves.

So if I had a linked list wrapper. And you call 
```wrapper.find_node(…)``` then the wrapper object should be able 
to signal that the returned node has the same lifetime.