Is it possible to handle 'magic' property assignments a'la PHP?

[Gary Willoughby]

On Saturday, 4 January 2014 at 19:17:31 UTC, Gary Willoughby 
wrote:
> OMG i've just found opDispatch!
>
> http://dlang.org/operatoroverloading.html#Dispatch
>
> Fantastic!

How to handle returning a value from a non-existent property?