[fpc-devel] Suggestion: reference counted objects

[Chriss Kalogeropoulos]

Hi Sven,

Yes I knew the problem in the latter approach. However my thinking is that
some features can be derived from others and I believe that this applies
here too.

So by adding these extension to records and the operator overload the
feature can be implemented as a library extension. Also those features
might benefit others and also provide the groundwork for more improvements
in the future.

In any case, all proposals are better than embarcaderos so I don't complain.

Thanks,
Chriss
 Στις 21 Σεπ 2014 3:39 μ.μ., ο χρήστης "Sven Barth" <
pascaldragon at googlemail.com> έγραψε:

> On 21.09.2014 14:15, Chriss Kalogeropoulos wrote:
>
>> Hi Sven,
>>
>> This design means that old classes need to be subclassed in order to
>> enable this feature,  correct?
>> Would it be possible instead of declaring this on the class definition,
>> to declare it on the actual variable? Something like
>>
>> var aArcObj: TFooObj; refcounted;
>>
>> Or similar.
>>
>> This would allow the same classes to be used both ways.
>>
>
> No. You would need to have a place where to store the reference count and
> one of the objections some people have is the size increase of TObject if
> it would get a RefCount field (which would be the only solution with your
> approach). Also you'd need to take care that all variables where you pass
> along your object instance are marked as refcounted. This just complicates
> things too much (both for programmers using this as well as for the
> compiler).
>
>  Also how about a smart pointer record  implementation with generics? Is
>> it possible ?
>>
>
> What's missing is the possiblity to hook into the initialization (unlike
> interfaces, strings and arrays class variables fields are not initialized
> with Nil) and finalization (you need to adjust the reference count) of
> records. And also it's currently not possible to overload the assignment
> operator if both types have the same record type.
>
> Regards,
> Sven
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