How to pass delegates to C functions?

[Justin Whear]

On Thu, 03 Apr 2014 17:59:30 +0000, Jeroen Bollen wrote:

> After being downvoted on stackoverflow for no apperant reason, I figured
> I'd give it a shot here.
> 
> How do I pass a delegate to an external C function taking a function
> pointer?
> 
> If you want some extra rep on StackOverflow you can also answer here:
> http://stackoverflow.com/questions/22845175/pass-delegates-to-external-
c-functions-in-d

Does the C function use the function pointer (call it), or just pass it 
around/store it?