How do I use null in a struct?

[Heromyth]

On Saturday, 10 November 2018 at 19:42:47 UTC, Václav Kozák wrote:
> I'm making a Rest API with vibe.d and I have a struct User. 
> Sometimes I need to return only a few of the fields. So for 
> example: return User(1, null, "John", null, null, ...);
> If I do this, an error occurs: cannot implicitly convert 
> expression null of type typeof(null) to ...
> Thanks.

Another choice: 
https://github.com/huntlabs/hunt/blob/master/source/hunt/lang/Nullable.d

This Nullable is a class and we are using it.