SerpentOS departs from Dlang

[Richard (Rikki) Andrew Cattermole]

On 17/09/2023 11:46 AM, Adam Wilson wrote:
> Kidding aside. If you do this, you might as well turn them on 
> everywhere. After that it's a easy stroll to a non-blocking moving GC, 
> which would end most complaints about the GC (nobody complains about the 
> .NET GC anymore).

The scope of each doesn't match up, and you'd still need the RC specific 
write barriers.

So when I say write barrier what I mean is:

```d
class MyRoot : void {
	void opRCWriteBarrier(size_t fieldOffset, void* pointer) {
		myCyclicDetector.set(cast(void*)this, fieldOffset, pointer);
	}

	void opRCSub() {
		if (atomicOp!"-="(this.refCount, 1) > 0)
			myCyclicDetector.collect(cast(void*)this);
	}
}

class Child : MyRoot {
	Array!int array;

	void func() {
		array = new Array!int();
		// this.opRCWriteBarrier(array.offsetof, cast(void*)array);
	}
}
```

Only needs to support classes + structs (I think), so its surface area 
is pretty small.

Oh and Walter has approved anyone to experiment with write barriers ages 
ago, although nobody has.