Example for multi level template composition

[user1234]

On Monday, 10 October 2022 at 06:30:05 UTC, Arun wrote:
> Stumbled upon this question on HN 
> https://news.ycombinator.com/item?id=33142751#33147401
>
>> Can I write template A and then apply it to itself to get 
>> template B and then apply that onto template C to get template 
>> D.
>
> Does anyone have an example for this?

Recursive templates can make other templates with themselves. I 
dont feel to provide an example ATM tho.