Is it time for D 3.0?

[shfit]

On Saturday, 28 March 2020 at 05:19:52 UTC, rikki cattermole 
wrote:
> On 28/03/2020 5:41 PM, Jesse Phillips wrote:
>> On Friday, 27 March 2020 at 15:56:40 UTC, Steven Schveighoffer 
>> wrote:
>>> There have been a lot of this pattern happening:
>>>
>>> 1. We need to add feature X, to fix problem Y.
>>> 2. This will break ALL CODE IN EXISTENCE
>>> 3. OK, cancel the fix, we'll just live with it.
>> 
>> 
>> Yes, but not because we want to break things, but because we 
>> are breaking things.
>> 
>> The preview switches are great, but can we get a grouped 
>> feature set for release.
>> 
>> It is critical that the existing libraries can be utilized 
>> with newer language versions (at least for a time).
>> 
>> Stationary is not an option, but a good upgrade which does not 
>> compromise the ecosystem is vital.
>
> I have said this before, D3 should be a preview switch which 
> turns on all the others.
>
> All D2 code should be compilable with D3, but not all D3 should 
> be compilable as D2.
>
> dmd3 could literally be the preview switch turned on 
> permanently.

I like this idea. It's simple and pragmatic. The documentation 
could recommend this to new users, who don't yet know what the 
right defaults should be, and everyone else could do the 
transition when they feel like it. At some point in the future it 
could be the default and the we could bump the version to D3.