opApply with Type Inference and Templates?

[Jerry via Digitalmars-d-learn]

I am trying to do opApply to work when the delegate passed when 
it is and isn't nogc/nothrow. As soon as you involve a template 
though, type inference goes out the door. I want to be able to 
use opApply with templates (to get the auto @nogc/nothrow 
deducation passed on the delegate passed) but still be able to 
use type inference. Is there any way to do this?