auto ref is on the docket

[via Digitalmars-d]

On Monday, 22 June 2015 at 18:10:11 UTC, Andrei Alexandrescu 
wrote:
> On 6/22/15 9:54 AM, "Marc =?UTF-8?B?U2Now7x0eiI=?= 
> <schuetzm at gmx.net>" wrote:
>> `auto ref` without a working `scope` implementation is unsafe.
>
> I'm unclear on this. With the existence of the return 
> attribute, what's unsafe about auto ref? -- Andrei

DIP25 _is_ a working `scope` implementation, for that matter, 
albeit incomplete. (Strictly speaking, it's not the `return` 
attribute that makes it safe, but the fact that under this 
proposal `ref` implies what `scope` was originally supposed to 
mean.)

You're right that if DIP25 is all we'll ever get (i.e. the 
`scope` keyword will never have any meaning), then `auto ref` 
might not be so bad a choice, although it still leaves the fact 
that it does something different for template and non-template 
functions. But it would create other inconsistencies with other 
kinds of references, e.g.

     void bar(ref MyStruct s);
     void foo(MyClass c);

     void baz() {
         MyStruct s;
         Scoped!MyClass c;
         bar(s); // safe
         foo(c); // not safe, reference may escape
     }

For consistency, I would much prefer if `ref` and scope-ness were 
kept independent, because they are orthogonal concepts. Why 
should one kind of reference imply `scope`, but not others?