[fpc-devel] Converting records back and forth. (Forward declarations for records needed ?!?)

[Hans-Peter Diettrich]

Skybuck Flying schrieb:
> Hello,
> 
> I want to write code as follows and I will simplify it here to illustrate
> the problem.
> 
> Let's say I want to kinds of records: TrecordA and TrecordB.
> 
> I want to be able to convert types of TrecordA to TrecordB but I also want
> to be able to convert types of TrecordB to TrecordA.
> 
> So I was thinking of writing code as follows:
> 
> type
>    TrecordA = record
>        function ToRecordB : TrecordB;
>    end;
> 
>    TrecordB = record
>        function ToRecordA : TrecordA;
>    end;

That's the wrong way. You should pass in an parameter of the output 
type, allocated by the caller. Then pass it as a pointer, and declare 
the pointer types before the records.

DoDi