message: Windows compiler crap 3
diff: @@ -273,12 +273,14 @@ public: // Load/append/remove interfaces
  size_type interval,
  bool start_from_beginning,
  const T &null_value = DataFrame::_get_nan<T>(),
  - std::function<DataFrame::size_type (
  - const DataFrame::IndexType &,
  - const DataFrame::IndexType &)> diff_func =
  - [](const DataFrame::IndexType &t_1,
  - const DataFrame::IndexType &t) -> DataFrame::size_type {
  - return (static_cast<DataFrame::size_type>(t - t_1));
  + std::function<typename DataFrame<I, H>::size_type (
  + const typename DataFrame<I, H>::IndexType &,
  + const typename DataFrame<I, H>::IndexType &)> diff_func =
  + [](const typename DataFrame<I, H>::IndexType &t_1,
  + const typename DataFrame<I, H>::IndexType &t) ->
  + typename DataFrame<I, H>::size_type {
  + return (
  + static_cast<typename DataFrame<I, H>::size_type>(t - t_1));
  });
  // It appends val to the end of the index column.
  