PackedAliasSeq?

[Seb]

On Thursday, 22 February 2018 at 19:26:54 UTC, Andrei 
Alexandrescu wrote:
> After coding https://github.com/dlang/phobos/pull/6192 with 
> AliasSeq, the experience has been quite pleasurable. However, 
> in places the AliasSeq tends to expand too eagerly, leading to 
> a need to "keep it together" e.g. when you need to pass two of 
> those to a template.
>
> [...]

You could also extend the existing `Pack` template:

https://github.com/dlang/phobos/blob/master/std/meta.d#L1704