Do we need a time-out in D evolution?

[BCS]

Reply to Walter,

> BCS wrote:
> 
>> Reply to Walter,
>> 
>>> BCS wrote:
>>> 
>>>> will the 2.0 series have an extern(D1) if and when somthing breaks
>>>> linking?
>>>> 
>>> No.
>>> 
>> Bummer
>> 
> It's not that it's a bad idea, it's just that it would be problematic
> to implement. What if the behavior of parts of Phobos changes, and one
> part of the code depends on 1 library behavior, and another part
> depends on 2? What if trying to accommodate both simultaneously is not
> practical? How to test all those combinations?
>

Well in that case I hope we'll get it when D2.0 comes out of beta. (or maybe 
alpha)


Aside:

This sort of plays into a thought I had as to how D might be able to avoid 
the mess that C++ seems to have gotten into. How about if each major version 
of D is not required to be backwards comparable with the last version. Where 
possible the extern(D<ver>) will be provided for backwards (and maybe forwards) 
compatibility.  However If code can't be mapped automatically, then it isn't 
directly callable and that is assumed to be the cost of keeping a clean language.