Adding a new design constraint to D

[Ola Fosheim Grøstad]

On Thursday, 16 June 2022 at 13:15:52 UTC, bauss wrote:
> On Thursday, 16 June 2022 at 13:02:11 UTC, Chris Katko wrote:
>> On Thursday, 16 June 2022 at 12:08:27 UTC, Ola Fosheim Grøstad 
>> wrote:
>>> If you can detect it, then it is a breaking change in the 
>>> context of meta-programming.
>>>
>>
>> Isn't that like saying: adding a uint128 type breaks the 
>> language. Because you can detect it?
>
> It is and I think it's far from a solid argument against 
> anything.

Actually, on second thoughts, it would not be a breaking change 
as it is listed in the language spec:

https://dlang.org/spec/type.html

I guess one could say that the compilers are not compliant, 
unless I missed a footnote somewhere.

Basically, whether it is a breaking change or not, depends on the 
wording of the language spec (if you have one). If it says that 
you should not assume this or that, then it is not a breaking 
change even if people do assume this or that (because the code 
they wrote was outside the spec and could be considered undefined 
behaviour).