Интерфейсы и подсчёт ссылок

// Отделите правило языка от удачного запуска InterfaceContract.
program InterfaceContract;
{$APPTYPE CONSOLE}
type
  IClock = interface
    ['{B7F27D1A-8778-4DCA-9EAB-1A4215AA0011}']
    function NowText: string;
  end;
  TClock = class(TInterfacedObject, IClock)
    function NowText: string;
  end;
function TClock.NowText: string;
begin Result := '12:00'; end;
var
  C: IClock;
begin
  C := TClock.Create;
  Writeln(C.NowText);
end.

// Определите реальную гарантию в MixedOwnership.
program MixedOwnership;
{$APPTYPE CONSOLE}
type
  IService = interface
    ['{B7F27D1A-8778-4DCA-9EAB-1A4215AA0014}']
    procedure Work;
  end;
  TService = class(TInterfacedObject, IService)
    procedure Work;
  end;
procedure TService.Work;
begin Writeln('work'); end;
var
  Obj: TService;
  Intf: IService;
begin
  Obj := TService.Create;
  Intf := Obj;
  Intf := nil;
  Obj.Free;
end.

// Проследите фактическое поведение RefCountMoment.
program RefCountMoment;
{$APPTYPE CONSOLE}
type
  IJob = interface
    ['{B7F27D1A-8778-4DCA-9EAB-1A4215AA0013}']
    procedure Run;
  end;
  TJob = class(TInterfacedObject, IJob)
    destructor Destroy; override;
    procedure Run;
  end;
destructor TJob.Destroy;
begin Writeln('destroy'); inherited; end;
procedure TJob.Run;
begin Writeln('run'); end;
procedure Execute(const J: IJob);
begin J.Run; end;
begin
  Execute(TJob.Create);
  Writeln('after');
end.

// Отделите правило языка от удачного запуска SupportsDemo.
program SupportsDemo;
{$APPTYPE CONSOLE}
uses System.SysUtils;
type
  IReadable = interface
    ['{B7F27D1A-8778-4DCA-9EAB-1A4215AA0012}']
    function ReadText: string;
  end;
var
  Obj: TObject;
  R: IReadable;
begin
  Obj := TObject.Create;
  try
    if Supports(Obj, IReadable, R) then
      Writeln(R.ReadText)
    else
      Writeln('not supported');
  finally
    Obj.Free;
  end;
end.