OK that's cool, I'll just avoid GDC for now. Is it generally a good approach to assume if something compiles in DMD then it's correct and just hope that GDC/LDC pick up the latest version at some point?
mostly yes. btw, ldc has devbuilds available from it's github page, those are usually on par with current dmd.
it is very sad that gdc has so little manpower, tho. Iain doing a great job, but...