Hi,

I have been poking around with overriding internal classes, and after reading [1] it was actually not clear to me whether it could be done or not, so I started trying.

The good news (for me, at least) is that it can mostly be done [2], whoever I have found a bit intriguing that I need to explicitly use "this.i" instead of just "i" in B.fb() [3].

Just in case, the code I got to work is this:

```
class A {
	public static class I {
		public string fai() {
			return "A.I.fai";
		}
	}
	
	public string fa() {
		return i.fai();
	}

	public this(this C)() {
		i_ = new C.I();
	}
	
	protected I i_;
	
	public @property T.I i(this T)() { return cast(T.I) this.i_; }
}

class B : A {
	override public static class I : A.I {
		override public string fai() {
			return "B.I.fai";
		}
		public string fbi() {
			return "B.I.fbi";
		}
	}
	public this(this C)() {
		super();
	}
	public string fb() {
		return this.i.fbi(); // Why is "this" needed here?
	}
}

void main() {
	A a = new A();
	A ab = new B();
	B b = new B();
	
	assert (a.fa() == "A.I.fai");
	assert (ab.fa() == "B.I.fai");
	assert (b.fa() == "B.I.fai");
	assert (b.fb() == "B.I.fbi");
}
```


Is there a reason for that? Why cannot it be inferred as in the regular case?

Also, if there's a way to do it without using the property wrapper, I'd be glad to know it :)

I tried something like:

```
template i(this T) {
    T.I i;
}
```
but it didn't like it... I guess members have to be better defined...

Best,

A


[1]: https://forum.dlang.org/thread/siwjqxiuocqtrldczand@forum.dlang.org
[2]: https://dpaste.dzfl.pl/8f4e0df438e5
[3]: https://dpaste.dzfl.pl/8f4e0df438e5#line-34