[boost] Preprocessor directive for a sequence that differs only in datatype

Subject: [boost] Preprocessor directive for a sequence that differs only in datatype
From: Rishabh Arora (rishabharora1997_at_[hidden])
Date: 2017-07-11 07:22:21

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