deprecate deprecated?

[Kagamin]

On Wednesday, 7 November 2012 at 02:55:38 UTC, Andrei 
Alexandrescu wrote:
> I don't think that's possible. One would need a mechanism to 
> hook into all calls to a function (adorned with a specific 
> attribute) and emit the message during compilation. That is 
> missing.

The attribute can be declared in library, but processed by the 
compiler - that's how C# works.
See
http://msdn.microsoft.com/en-us/library/system.threadstaticattribute.aspx
http://msdn.microsoft.com/en-us/library/System.Diagnostics.ConditionalAttribute.aspx