Maybe<T> ObjPascal

type
    IMaybe<T> = Interface
   ['{1E034B6C-6CAF-4825-A147-2306393B9056}']
   function NullValue:Any; overload;
   function Value: T; overload;
   function Value(Arg: TProc<T,Any>): T; overload;
 End;

 Type
   TMaybe<T: constructor> = Class(TInterfacedObject,IMaybe<T>)

  private
  {Private declaration}
   var FValue: Any;
       FNullValue: Variant;
   function ObjisNull:Any; virtual; Abstract;
  protected
  {Protected declaration}
   function ContractsRequired:Any;
   function TryGetValue:T;
  public
  {Public declaration declaration}
   class function New(Arg: T  ): T;
 End;