[fpc-devel] properties accessing field of nested object ?

Michael Van Canneyt michael at freepascal.org
Mon May 13 08:47:56 CEST 2013

On Sun, 12 May 2013, Martin wrote:

> I know a property read/write to a member of a record, if that record is a 
> field of the class.
> I tested the following code, it seems fpc also allows that for classes.
> type
>  TFoo = class
>  protected
>    cn: Integer;
>  end;
>  TForm1 = class(TForm)
>  private
>    a:TFoo;
>  public
>    property b: Integer read a.cn write a.cn;
>  end;
> I have not tested it at runtime.... I assume it depend on a being initialized 
> with an instance.
> Question, is that allowed by intention? That is can I trust that it will be 
> supported by future fpc versions?
> Or is that a missing check somewhere, and bay stop working in future?

I think the latter, unless this was added recently as a feature.
At least in RTTI there is no support for getting/setting fields 
as part of a class-typed field?


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