[fpc-pascal] Empty record inside another record ?

[Vincent Snijders]

Tiziano De Togni schreef:
> Florian Klaempfl ha scritto:
>> Skybuck Flying schrieb:
>>> One drawback of objects already discovered:
>>>
>>> Objects cannot have the same field identifiers.
>>
>> Indeed, especially if you want to win an obfuscation contest.
> 
> ok, this is true for object type, but it should not be extended to class
> types. Look at this example taken from Delphi Help:
> 
> type
>   TAncestor = class
>     Value: Integer;
>   end;
> 
>   TDescendant = class(TAncestor)
>     Value: string;  // hides the inherited Value field
>   end;
> 
> var
>   MyObject: TAncestor;
> 
> begin
>   MyObject := TDescendant.Create;
>   // MyObject.Value := 'Hello!';  // error
>   TDescendant(MyObject).Value := 'Hello!';  // works!
> end;
> 
> it compiles correctly in Delphi (5 and 7) but FPC (v2.2.0 - compiled 
> with Params Values=" -S2cdgi -OG1 -gl -WG -vewnhi") still says
> that there is a duplicate identifier "Value"...
> 
> am I correct?
> 

This is not allowed in {$mode objfpc}, because of the reasons Florian memtioned. It 
is allowed in {$mode delphi}.

Vincent