Why the @ in @safe? & UDAs

[John Colvin]

On Sunday, 10 November 2013 at 19:24:53 UTC, Andrei Alexandrescu 
wrote:
> On 11/10/13 11:14 AM, Timon Gehr wrote:
>> On 11/10/2013 05:39 PM, Andrei Alexandrescu wrote:
>>> On 11/9/13 1:27 AM, SomeDude wrote:
>>>> I would add that constant breaking changes make the language 
>>>> unfit for
>>>> industrial usage in the long term.
>>>> Let's remember that D is being pushed in production by 
>>>> Andrei at
>>>> Facebook. If the language breaks everything at each release, 
>>>> there is no
>>>> way Facebook or any other company for that matter is going 
>>>> to bet a dime
>>>> on it.
>>>
>>> Agreed with qualifications. We at Facebook are well aware 
>>> that bumping
>>> the gcc release will inevitably cause breakages, and are able 
>>> and
>>> willing to put up with them for the sake of the benefits. 
>>> This of course
>>> is guided by the breakage/benefits ratio.
>>>
>>> Andrei
>>>
>>
>> What about just shipping a fully automated fix-up tool when 
>> trivial but
>> major breaking changes happen?
>
> That's nice because in a good way it puts the onus on the 
> breakers. For it to be useful, the tool would have to be rock 
> solid and work in 100% cases.
>
> Andrei

string mixins?