Direct recursion detection possible?

[Cecil Ward]

On Thursday, 25 May 2023 at 10:35:45 UTC, Quirin Schroll wrote:
> On Wednesday, 24 May 2023 at 23:04:53 UTC, Cecil Ward wrote:
>> [...]
>
> I had this almost happen in my C++ code. It never ran because I 
> got a compile error. The compiler is MSVC.
>
> [...]

My apologies, when I wrote ‘straightforward’ I should meant to 
say, ‘without body, with no content’. You mentioned without 
side-effects, which is more general and very useful.