If the array to be converted is empty, as represented by '( 0, () )', the resulting seq is undefined since a seq cannot be empty.
#include <boost/preprocessor/array/to_seq.hpp>
BOOST_PP_ARRAY_TO_SEQ((3, (a, b, c))) // expands to (a)(b)(c)
Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at www.boost.org/LICENSE_1_0.txt)