Delphi-Equivalent zur C-union

[NicoDE]

Das lässt sich nur mit vielen Tricks übersetzen.
(wer auch immer unbenannte unions benutzt, gehört...)

Delphi-Quellcode:

(** Unnamed unions are evil stuff.

typedef struct CvMat
{
  int  type;
  int  step;
  int* refcount;
  union
  {
    uchar*  ptr;
    short*  s;
    int*    i;
    float*  fl;
    double* db;
  } data;
  union
  {
    int rows;
    int height;
  };
  union
  {
    int cols;
    int width;
  };
} CvMat;

**)

type
  CvMat = record
    type_       : Integer;
    step        : Integer;
    (* for internal use only *)
    refcount    : PInteger;
    data        : record
      case Integer of
        0: (ptr : PByte);
        1: (s   : PSmallInt);
        2: (i   : PInteger);
        3: (fl  : PSingle);
        4: (db  : PDouble)
    end;
    case Integer of
      0: (rows  : Integer);
      1: (height: Integer;
    case Integer of
      0: (cols  : Integer);
      1: (width : Integer))
  end;

// unit testing

procedure TForm1.FormCreate(Sender: TObject);
  function FielsOffset(const Struct; const Field): string;
  begin
    Result := IntToHex(Cardinal(Addr(Field)) - Cardinal(Addr(Struct)), 8);
  end;
  var
    Foo: CvMat;
    Txt: string;
begin
  Txt :=
    'type_    ' + FielsOffset(Foo, Foo.type_   ) + #13#10 +  // 00000000
    'step     ' + FielsOffset(Foo, Foo.step    ) + #13#10 +  // 00000004
    'refcount ' + FielsOffset(Foo, Foo.refcount) + #13#10 +  // 00000008
    'data     ' + FielsOffset(Foo, Foo.data    ) + #13#10 +  // 0000000C
    '  ptr    ' + FielsOffset(Foo, Foo.data.ptr) + #13#10 +  // 0000000C
    '  s      ' + FielsOffset(Foo, Foo.data.s  ) + #13#10 +  // 0000000C
    '  i      ' + FielsOffset(Foo, Foo.data.i  ) + #13#10 +  // 0000000C
    '  fl     ' + FielsOffset(Foo, Foo.data.fl ) + #13#10 +  // 0000000C
    '  db     ' + FielsOffset(Foo, Foo.data.db ) + #13#10 +  // 0000000C
    'rows     ' + FielsOffset(Foo, Foo.rows    ) + #13#10 +  // 00000010
    'height   ' + FielsOffset(Foo, Foo.height  ) + #13#10 +  // 00000010
    'cols     ' + FielsOffset(Foo, Foo.cols    ) + #13#10 +  // 00000014
    'width    ' + FielsOffset(Foo, Foo.width   ) + #13#10 +  // 00000014
    '(SizeOf) ' + IntToHex(SizeOf(CvMat), 8);                // 00000018
  ShowMessage(Txt);
end;

ps: keine Ursache, hab's gerade nochmal vereinfacht (der Rest war Routine )