TNullable

type TNullable = record

public

type

  TMyType = TMyType;

public

  procedure Clear;

  property HasValue: Boolean; [rw]

  property IsNull: Boolean; [r]

  property Value: T; [rw]

  property ValueOrDefault: T; [r]

  class function Empty;

  class operator initialize(TNullable)();

  class operator explicit(T):TMyType();

  class operator explicit(TMyType):T();

  class operator assign(T):TMyType();

  class operator assign(TMyType):T();

end;