> On Jan 8, 2017, at 2:37 AM, Andrew Hall <[email protected]> wrote:
>
> If you cast your “something” to a typed pointer, the compiler will do the
> work for you in the usual way:
>
> PDouble(something)^ := myDouble;
> PAnsiString(something)^ := myAnsiString;
> myRecordStructure := PMyRecordStructure(something)^;
I’m not getting any of this to work.
Here is the pattern I was attempting. It’s a “release existing, retain and
assign new” function which handles nil inputs safely. I thought I could use
untyped params so I don’t need to typecast “io” to TObject when I call
RetainObject every time.
procedure RetainObject (var io; newObject: TObject);
var
obj: TObject absolute io;
begin
if obj <> nil then
obj.Release;
if newObject <> nil then
begin
obj := newObject;
obj.Retain;
end
else
obj := nil;
TObjectPtr(io)^ := obj; // crashes here
end;
var
foo: TMyObject;
something: TMyObject;
foo := TMyObject.Create;
RetainObject(something, foo);
Regards,
Ryan Joseph
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