FPC TObject Helper Self

program Project1;

{$mode objfpc}{$H+}

uses
    Classes, sysutils;

type
    TObjHelper = class helper for TObject
        function HelperSelf: TObject;
    end;


function TObjHelper.HelperSelf: TObject;
begin
     result:=self;
end;


type
    TNewType = class
       var
          Name: string;
       procedure WriteName(nt: TNewType);

    end;

procedure TNewType.WriteName(nt: TNewType);
begin
     WriteLn('Object name=>', QuotedStr(nt.Name));
end;

var
   o: TObject;
   nt1, nt2: TNewType;
begin
     nt1:=TNewType.Create;
     nt1.Name:='nt1';

     nt2:=TNewType.Create;
     nt2.Name:='nt2';

     with nt1 do
        nt2.WriteName(HelperSelf as TNewType);

     nt1.WriteName(nt2);
end.