Extracting user defined attributes on function parameters

[Adam D. Ruppe]

On Friday, 17 April 2020 at 18:05:39 UTC, Jean-Louis Leroy wrote:
> Interesting example, but all hope is not lost. `a` could 
> (should?) be passed as an alias in __parameters.

Well, __parameters itself actually kinda works. The compiler 
knows it is an expression and can stringify it or evaluate it on 
demand for you...

but how to express that in D code is pretty weird and idk how to 
library that. Using in-site for various things can be done but 
putting it in a lib is idk.