Source code annotations alla Java

[Trass3r]

> class Foo
> {
>      int x;
>      int y;
>      int z;
>
>      mixin NonSerialized!(z);
> }

Had a quick look at  
http://dsource.org/projects/orange/browser/orange/serialization/Serializable.d
1. How come it works without 'mixin' in the template declaration (mixin  
template NonSerialized)?
2. What if several fields need to be tagged?
3. Is there a reason to use a struct instead of e.g. __nonSerialized =  
["field1", "field2", ...]?
4. Couldn't that field be static to save space or maybe even enum?