RDataFrame: sub-par diagnostics for interpreted types

     #include <ROOT/RDataFrame.hxx>

     using namespace ROOT;

     struct re{

         double a;

         double b;

     };

   re j2000(double k)

     {

       res c;

       c.a = 0;

       c.b = 0;

       return c;

     }

     void p4_radec()

     {

         RDataFrame aDataIn("result", "data/*.root");

         aDataIn

             .Define("res", j2000, {"x"})

             .Snapshot("result", "RESULT2.root");

         ;

     }

     int main()

     {

       p4_radec();

     }