DIP69 - Implement scope for escape proof references

[deadalnix via Digitalmars-d]

On Friday, 12 December 2014 at 06:06:40 UTC, Dicebot wrote:
> On Thursday, 11 December 2014 at 21:41:11 UTC, Walter Bright 
> wrote:
>> Consider a ref counted type, RC!T. If scope were transitive, 
>> then you could not have, say, a tree where the edges were 
>> RC!T. I.e., the payload of an RC type should not be forced to 
>> be scope.
>
> I don't see how this is related. It would be perfectly ok to 
> declare root of such tree scope if it was transitive (as long 
> as it only controls access and does not attempt early 
> destruction).
>

That is my proposal. However, it is not as simply as you think it 
is without making it a type qualifier (which is not desirable).

In effect, that mean that you can see something that has infinite 
lifetime through a scope reference, so you need to track lifetime 
rvalue and lvalue differently.

I'm still for it. The current proposal is not powerful enough to 
pull its weight.