is there a way to get the identifier (call it name) of what is being passed to a function ?

[SealabJaster]

On Monday, 19 July 2021 at 03:51:02 UTC, SealabJaster wrote:
> ...

There's also Ali Cehreli's book, which is excellent.

e.g. here's the section on UDAs: 
http://ddili.org/ders/d.en/uda.html