Destructors can't be @nogc?

[Paul Backus]

On Saturday, 24 July 2021 at 02:02:00 UTC, Mike Parker wrote:
> On Friday, 23 July 2021 at 20:24:02 UTC, Jim wrote:
>
>> What is the problem here? Should I not call `destroy`? If so, 
>> what should I call instead?
>
> The problem is that you've marked main as `@nogc`, and 
> `destroy` is not `@nogc`. Remove the annotation from main and 
> it will compile.

Which raises the question, *why* is `destroy` not `@nogc` when 
the destructor is `@nogc`? And it turns out the answer is that 
[it calls `rt_finalize`][1], which [takes its argument as a 
`void*`][2] and therefore has to assume that any destructor it 
calls *might* use the GC.

[1]: 
https://github.com/dlang/druntime/blob/v2.097.1/src/object.d#L3970
[2]: 
https://github.com/dlang/druntime/blob/v2.097.1/src/rt/lifetime.d#L1438