Is there a way to get a compile-time list of all user classes?

[Adam D. Ruppe via Digitalmars-d-learn]

On Thursday, 12 January 2017 at 20:58:33 UTC, Max wrote:
> I would like to get as a result a list of all classes that 
> implement a specific user interface. Is there a way to do this?

Not at compile time, it is possible there are child classes in 
separately compiled modules or libraries (or even runtime 
plugins).