message: das: improve error message
diff: @@ -405,7 +405,10 @@ namespace elle
  , _prototype(DefaultStore<make_default<Args>...>(
  std::forward<CArgs>(args)...))
  {
  - static_assert(sizeof ... (Args) == sizeof ... (args), "LOLEUH");
  + static_assert(sizeof ... (Args) <= sizeof ... (args),
  + "too few effective arguments compared to signature");
  + static_assert(sizeof ... (Args) >= sizeof ... (args),
  + "too many effective arguments compared to signature");
  }
  template <typename ... Effective>
  