On Monday, 28 August 2017 at 22:47:12 UTC, Andre Pany wrote:
On Monday, 28 August 2017 at 22:28:18 UTC, Moritz Maxeiner
wrote:
On Monday, 28 August 2017 at 21:52:58 UTC, Andre Pany wrote:
[...]
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?
[...]
Add an explicit class reference member to to it:
---
class TCustomGrid: TCustomPresentedScrollBox
{
struct ColumnsArray
{
TCustomGrid parent;
TColumn opIndex(int index)
{
int r = getIntegerIndexedPropertyReference(reference,
"Columns", index);
return new TColumn(r);
}
}
ColumnsArray Columns;
this()
{
Columns = ColumnsArray(this);
}
...
}
---
Nesting structs inside anything other than functions[1] is for
visibility/protection encapsulation and namespacing only.
[1] non-static structs in functions are special as they have
access to the surrounding stack frame
Unfortunately thats not possible. ColumnsArray and the
attribute will become a string mixin to avoid boilerplate.
It would be error prone if I have to initialize them in the
constructor too. I want just 1 single coding line for this
property. That is also the reason I do not want to use a class,
as I would have to initialize them in the constructor.
---
class C
{
struct S
{
}
S s;
}
---
is semantically equivalent to
---
struct S
{
}
class C
{
S s;
}
---
with the two differences being
- namespacing (outside of C one has to use C.S to access S)
- you can protect the visibility of the S from outside the module
C resides in via private,public, etc.
In both cases S doesn't inherently how about C, which means a
solution using default initialization is not feasible, as S.init
can't know about any particular instance of C.
I don't think there's any way for you to avoid using a class
constructor.
