`in` no longer same as `const ref`

[Radu via Digitalmars-d]

On Monday, 30 January 2017 at 08:02:12 UTC, Walter Bright wrote:
> On 1/29/2017 9:50 PM, Nordlöw wrote:
>> Will we make them equal in the long run? So much shorter to 
>> read.
>
> I know it's shorter. I'd like to do it too, we'll have to see.

Can it be enabled for -dip1000 flag?
Doc was pretty clear on what it was suppose to do and people 
kinda knew that scope was not finished.

Having it turned on for dip flag will allow some testing of the 
existing code. I would like to have in's intended semantic 
finally implemented.