种的只读属性形同虚设

类的只读属性形同虚设？
代码如下，只读属性的值还是被修改了！算是“漏洞”吧？

Delphi(Pascal) code

type  TForm1 = class(TForm)    Button1: TButton;    procedure FormCreate(Sender: TObject);    procedure Button1Click(Sender: TObject);  private    { Private declarations }    Fa: Integer;  public    { Public declarations }    property a: Integer read Fa;  end;var  Form1: TForm1;implementation{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);begin  showmessage(IntToStr(a))end;procedure TForm1.FormCreate(Sender: TObject);begin  PInteger(@a)^ := 123;{通过指针方式修改只读属性的值}end;