> On Feb 14, 2021, at 11:14 AM, Sven Barth via fpc-pascal
> <fpc-pascal@lists.freepascal.org> wrote:
>
> It's a runtime conversion, but normally you don't do the conversion for every
> method call, but instead cache the interface (or work solely with the
> interface), thus the performance impact through the conversion amortizes (and
> again, there's so memory allocation by the conversion itself, of course if
> the interface getter in case of a interface delegation does a lazy
> initialization that's different, but the conversion itself does not require
> an allocation).
For default properties no conversion needs to take place even because the
compiler can simply find the correct method and return a modified self which
points to the struct, like "self.fMyRec" in the example below. In this case the
interface doesn't really do anything does it? I think the VMT table is modified
and you should probably use CORBA interface unless you want reference counting
and extra baggage when you instantiate the class (I assume). If we use records
then the memory should be unified (which is good) and with CORBA interfaces no
significant baggage during instantiation. Correct me where I'm wrong please.
=====================
type
TMyRec = record
procedure DoX;
end;
IMyIntf = interface
procedure DoX;
end;
TMyClass = class(TInterfacedObject, IMyIntf)
private
fMyRec: TMyRec;
public
property MyRec: TMyRec read fMyRec implements IMyIntf; default;
end;
Regards,
Ryan Joseph
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