[fpc-pascal] Incompatible type for generics?

[Sven Barth]

Am 24.09.2013 15:50, schrieb Xiangrong Fang:
> Hi Sven,
>
> 2013/9/23 Xiangrong Fang <xrfang at gmail.com <mailto:xrfang at gmail.com>>
>
>         Short answer: you can't. The same would happen with normal
>         classes.
>
>         Long answer: You could add an additional method "Next" to your
>         "TIntTree" which returns a "TIntTree" and just do "Result :=
>         TIntTree(inherited Next);" there.
>
> I still have problem with this strange issue.   See the demo program 
> below:
>
> program test;
> {$mode objfpc}{$H+}
> uses treap;
> type
>   TStringMapper = class(specialize TTreap<string, string>)
>   end;
> var
>   sm1, sm2: TStringMapper;
>   n: TStringMapper.PNode;
> begin
>   sm1 := TStringMapper.Create;
>   for n in sm1.Reversed do WriteLn(n^.Key);   <-- but NOT here
>   sm2 := sm1.Reversed;                        <-- error here
> end.
How is PNode declared? What is the exact error?
> Why is this?  Also, I found that the keyword "specialize" is 
> recognized in fpc mode, but "class" is only valid in objfpc mode, is 
> that correct?
"specialize" is used in all modes except mode Delphi for 
specializations. "class" is available in all modes except "iso", "tp" 
and "fpc", but can be enabled there using {$modeswitch class}.

Regards,
Sven

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freepascal.org/pipermail/fpc-pascal/attachments/20130924/b96472ff/attachment.html>