Is there anyway to make opApply @nogc?

[Gary Willoughby via Digitalmars-d-learn]

On Monday, 20 June 2016 at 15:27:32 UTC, Adam D. Ruppe wrote:
> On Monday, 20 June 2016 at 15:13:53 UTC, Gary Willoughby wrote:
>> I think the problem is that the delegate which is required by 
>> opApply is allocated using the GC.
>
> make the delegate in opApply scope
>
> int opApply(scope int delegate(whatever) dg)

What effect does this have? and how does it beat the GC?