DIP69 - Implement scope for escape proof references

[Walter Bright via Digitalmars-d]

On 12/5/2014 7:27 AM, Steven Schveighoffer wrote:
> Can someone who knows what this new feature is supposed to do give some Ali
> Çehreli-like description on the feature? Basically, let's strip out the *proof*
> in the DIP (the how it works and why we have it), and focus on how it is to be
> used.
>
> I still am having a hard time wrapping my head around the benefits and when to
> use scope, scope ref, why I would use it. I'm worried that we are adding all
> this complication and it will confuse the shit out of users, to the point where
> they won't use it.

The tl;dr version is when a declaration is tagged with 'scope', the contents of 
that variable will not escape the lifetime of that declaration.

It means that this code will be safe:

    void foo(scope int* p);

    p = malloc(n);
    foo(p);
    free(p);

The rest is all the nuts and bolts of making that work.