[fpc-pascal] Re: Objects in dynamic arrays

[Andreas Schneider]

On Saturday, November 16, 2013, at 02:36 Martin wrote:
> On 16/11/2013 01:03, Timothy Groves wrote:
>>
>> Here's the code I *actually* have in the method:
>>
>> var
>>   index,
>>   last : integer;
>> begin
>>   last := length (t_volumes) - 1;
>>   index := 0;
>>   while ((t_volumes [index] <> t_current_volume) and (index < last)) do
>>       inc (index);
>>   if (index < last) then begin
>>     t_volumes [index] := t_volumes [last];
> Objects are actually stored via a reference (internal pointer)
> So t_volumes [last] just points to the objects data
>
> The above statement duplicates the reference
>
>> t_volumes [last].Destroy;
>
> destroys the object pointed to by both: t_volumes [last] and t_volumes
> [index]
>
> You should have destroyed t_volumes [index] *before* copying the value

Maybe a bit late, but that might not be true.
If  Timothy  really talks about _object_ (and not _class(TObject)_) it
should work as he does it. Also Destroy would probably be appropriate.

Just saying :-)

The actual type defs used are missing.

-- 
Best Regards,
Andreas