Hello Everyone, 
I was trying to use the boost.preprocessor to write some code which otherwise needs to be written for all the cases. 
Here's the code: https://github.com/BoostGSoC17/dataframe/blob/master/include/df.cpp (line no. 430 and 431).
But on compilation it gives the error: 
error: macro "BOOST_PP_SEQ_ELEM_III" requires 2 arguments, but only 1 given
     print_column <BOOST_PP_SEQ_ELEM(type, INNER_TYPE) >(i);

I didn't understand the reason as when I wrote: print_column <BOOST_PP_SEQ_ELEM(any_numerical_value(0, 1, ...), INNER_TYPE) >(i); it works fine. 
Can anyone help me understand the error or provide an alternative way to do the same thing? 

Thanks in advance, 

Best Regards, 
Rishabh