How long does the context of a delegate exist?

[Paul Backus]

On Sunday, 30 May 2021 at 09:39:28 UTC, cc wrote:
>
> Is there any way to enforce at compile time that we're not 
> accidentally allocating when creating a delegate, other than 
> being carefully aware of what variables are referenced inside 
> the body?  Something like:
> ```d
> auto dg = delegate {...}
> assert(dg.ptr is null, "Oops, we unintentionally allocated on 
> GC here, check delegate body!"); // can't static assert
> ```

`@nogc`. Or check the output of `dmd -vgc` if you want something 
less strict.