program Project11;

{$APPTYPE CONSOLE}

{$R *.res}

uses
  System.SysUtils;

type
  TStringHelper = record helper for String
    procedure add(str: string);
  end;

  TXXX = class
  private
    FA: String;
    function getA: String;
    procedure setA(const Value: String);
  published
    property a: String read getA write setA;
  end;


{ TStringHelper }

procedure TStringHelper.add(str: string);
begin
  Self:=Self+#13#10+Str;
end;

{ TXXX }

function TXXX.getA: String;
begin
  Result := FA;
  WriteLn('Get:'+FA);
end;

procedure TXXX.setA(const Value: String);
begin
  FA := Value;
  WriteLn('Set:'+FA);
end;

var
  X : TXXX;

begin
  x:=TXXX.Create;
  WriteLN('----- Set A directly------');
  x.a:='123';
  WriteLN('----- "Set" A through helper ------');
  x.a.add('456');
  WriteLN('----- Get result ------');
  WriteLN(x.a);

  ReadLn;
end.