The BOOST_PP_SEQ_FIRST_N macro expands to a seq of the first n elements of a seq.

Usage

BOOST_PP_SEQ_FIRST_N(n, list)

Arguments

n
The number of elements to extract.
list
The seq from which the elements are extracted.

Remarks

This macro extracts n elements from the beginning of seq and returns them as a new seq

See Also

Requirements

Header:  <boost/preprocessor/seq/first_n.hpp>

Sample Code 

#include <boost/preprocessor/seq/first_n.hpp>

#define SEQ (a)(b)(c)(d)(e)

BOOST_PP_SEQ_FIRST_N(2, SEQ) // expands to (a)(b)