Force struct allocation on the heap?

[Benji Smith]

Looking at the official docs, I can't find the D1 syntax for forcing a 
struct to be allocated on the heap (so that it can safely be returned 
from a function). I'm pretty sure it's possible (without wrapping the 
struct in a class or an array), but I can't for the life of me remember 
how it's done.

Thanks for your help!
--benji