Adding to a global AliasSeq

[repr_man]

On Tuesday, 15 August 2023 at 07:02:45 UTC, Basile B. wrote:
> You can add a kind of tag with the mixin, that will allow to to 
> test if the type supplied to `f` is well a Base implementor:
Firstly, thank you for your help.  This is probably the best 
solution.

Secondly, I feel very stupid for not having come up with this by 
myself.  Would you be willing to explain some of the thought 
process behind your solution?  Are there any key factors that I 
should look for in future template-related problems?  Or, if it 
just comes from experience and seeing this sort of thing 
repeatedly, that's fair, too.

Thanks, once again!