Transitioning std lib modules/packages

[Andrea Fontana via Digitalmars-d]

On Monday, 28 November 2016 at 13:42:30 UTC, Andrea Fontana wrote:
> On Monday, 28 November 2016 at 13:34:42 UTC, Andrei 
> Alexandrescu wrote:
>> On 11/28/2016 04:13 AM, Andrea Fontana wrote:
>>> Hoping std.v2.stdio works and it's an alias to std.stdio.
>>
>> That doesn't work - how do you later make breaking changes to 
>> std.v2.stdio? We'd be missing the very point of doing this. -- 
>> Andrei
>
> It's just an api level. When you need a breaking change all 
> modules will be updated to v3 as alias except the edited ones.
>
> V3 it just like a commit-id on github.

So every (breaking) phobos release import the last version of 
each module.

If i have an old code to support i just need to compile with:

dmd .... -version=PHOBOS_API_LEVEL_2

and

import std.stdio; // will import std.v2.stdio instead of 
predefine std.v3.stdio