Using closure in function scope to make "real" private class members

[bauss]

On Wednesday, 8 June 2022 at 09:38:24 UTC, Ola Fosheim Grøstad 
wrote:
> On Wednesday, 8 June 2022 at 09:34:09 UTC, forkit wrote:
>> Walter has his firm view. I have mine.
>
> Sure, your viewpoint would make sense for D3, but then there 
> would be many such adjustments to make.
>
> To make all those adjustments in D2 with no breaking change 
> would @lead @to @a @mess.

Not in this case. I already proposed something that can work 
without providing attribute soup.

Just extend the private access modifier to allow an optional 
specifier such as class/struct.

https://forum.dlang.org/post/wmamhwkfdqgzaqndgaus@forum.dlang.org

Ex.

```
class Foo
{
   private int a; // private to module
   private class int b; // private to class
}
```