message: das.named: Expose Super type in Function::Result.
diff: @@ -450,6 +450,7 @@ namespace elle
  : public elle::Option<R, std::exception_ptr>
  {
  public:
  + using Super = elle::Option<R, std::exception_ptr>;
  using elle::Option<R, std::exception_ptr>::Option;
  R
  operator()()
  