Accessing outer class attribute from inner struct

[Andre Pany via Digitalmars-d-learn]

Hi,

I build some framework to access Delphi components from D.
Delphi supports property array access "StringGrid1.Columns[2]" 
which is translated in Delphi to a private method call 
"GetColumn(2)".

I need to imitate this behavior in my D code.
Therefore my TCustomGrid class has a inner struct ColumnsArray 
with an opIndex.
While accessing opIndex I need to call a DLL method. Therefore I 
need the "reference" attribute which is available in my 
TCustomGrid via inheritance.

To make my question short:) If ColumnsArray is a class I can 
access the attribute "reference" but not if it is a struct. I 
would rather prefer a struct, but with a struct
it seems I cannot access "reference".

How can I access "reference" from my inner struct?

class TCustomGrid: TCustomPresentedScrollBox
{       
        struct ColumnsArray
        {
                TColumn opIndex(int index)
                {
			int r = getIntegerIndexedPropertyReference(reference, 
"Columns", index);
                        return new TColumn(r);
                }
        }
        
        ColumnsArray Columns;
...
}

Kind regards
André