Does `is` expression with template alias need fixing.

[Elfstone]

On Wednesday, 22 March 2023 at 11:00:40 UTC, zjh wrote:
> On Wednesday, 22 March 2023 at 10:43:15 UTC, Elfstone wrote:
>> ```C++
>> template <typename T>
>> using Vector3 = Matrix<T, 3, 1>;
>> ```
>>
>> I declare an alias and I use it everywhere. It acts as a 
>> natural constraint. I never needed `isVector3` with my old C++ 
>> code. I expected D could do the same, and was really 
>> frustrated when I found out it couldn't. Even more frustrated 
>> when I read Steven's reply, that the bug with `is` has been 
>> there for 16 years.
>>
>
> When you have questions, please file a bugzilla.
> D is only for `specific problems`, please describe the problem 
> carefully.

There are already a ton issues about this filed, including 
Steven's 16 years old one. It seems the community lacks the 
motivation to fix it. That's why I started this thread.