message: Did a workaround for MS C++ compiler bug 2
diff: @@ -79,7 +79,7 @@ struct NotImplemented : public DataFrameError {
  // ----------------------------------------------------------------------------
  -inline constexpr const char *const DF_INDEX_COL_NAME = "INDEX";
  +inline constexpr const char *DF_INDEX_COL_NAME = "INDEX";
  // ----------------------------------------------------------------------------
  