/*============================================================================= Copyright (c) 2017 Paul Fultz II unpack.cpp Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) ==============================================================================*/ #include struct foo {}; namespace boost { namespace hof { template<> struct unpack_sequence { template constexpr static int apply(F&&, S&&) { return 0; } }; } int main() { boost::hof::unpack(boost::hof::always(1))(foo{}); }