Can your programming language do this?

[Piotr Szturmaj]

Andrew Wiley wrote:
> I know I keep beating this horse, but in other languages, this is the
> textbook example for why annotations are useful. Adding metadata to
> code, even if it can only be examined at compile time, can be immensely
> useful.

I fully agree. However, I did create some substitute:

struct City
{
     Serial!int id; // auto increment
     string name;

     mixin PrimaryKey!(id);
     mixin Unique!(name);
}

but still, legal attributes such as .NET ones would be more appreciated.