Try a1.template get<0>();
I tried this, and get the following error : /usr/lib/gcc/i386-redhat-linux/4.3.2/../../../../include/c++/4.3.2/bits/stl_algo.h: In function ‘_Funct std::for_each(_IIter, _IIter, _Funct) [with _IIter = boost::zip_iterator<boost::tuples::tuple<__gnu_cxx::__normal_iterator<int*, std::vector<int, std::allocator<int> > >, __gnu_cxx::__normal_iterator<int*, std::vector<int, std::allocator<int> > >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >, _Funct = boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::shift_left_eval, boost::fusion::vector<boost::phoenix::reference<std::basic_ostream<char, std::char_traits<char> > >, boost::phoenix::composite<boost::phoenix::detail::function_eval<1>, boost::fusion::vector<boost::phoenix::value<get0_>, boost::phoenix::argument<0>, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> >
]’: zip.cpp:54: instantiated from here /usr/lib/gcc/i386-redhat-linux/4.3.2/../../../../include/c++/4.3.2/bits/stl_algo.h:3791: error: no match for call to ‘(boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::shift_left_eval, boost::fusion::vector<boost::phoenix::reference<std::basic_ostream<char, std::char_traits<char> > >, boost::phoenix::composite<boost::phoenix::detail::function_eval<1>, boost::fusion::vector<boost::phoenix::value<get0_>, boost::phoenix::argument<0>, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > >) (boost::tuples::cons<int&, boost::tuples::cons<int&, boost::tuples::null_type> >)’ /x/mkudlur/boost/boost-trunk/boost/spirit/home/phoenix/core/actor.hpp:90: note: candidates are: typename boost::mpl::eval_if<typename Eval::no_nullary, boost::mpl::identity<boost::phoenix::detail::error_expecting_arguments>, boost::phoenix::eval_result<Eval, boost::phoenix::basic_environment<boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> > ::type boost::phoenix::actor<Eval>::operator()() const [with Eval = boost::phoenix::composite<boost::phoenix::shift_left_eval, boost::fusion::vector<boost::phoenix::reference<std::basic_ostream<char, std::char_traits<char> > >, boost::phoenix::composite<boost::phoenix::detail::function_eval<1>, boost::fusion::vector<boost::phoenix::value<get0_>, boost::phoenix::argument<0>, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> >] /x/mkudlur/boost/boost-trunk/boost/spirit/home/phoenix/core/actor.hpp:107: note: typename boost::phoenix::actor<Eval>::result<boost::phoenix::actor<Eval> ()(T0&)>::type boost::phoenix::actor<Eval>::operator()(T0&) const [with T0 = boost::tuples::cons<int&, boost::tuples::cons<int&, boost::tuples::null_type> >, Eval = boost::phoenix::composite<boost::phoenix::shift_left_eval, boost::fusion::vector<boost::phoenix::reference<std::basic_ostream<char, std::char_traits<char> > >, boost::phoenix::composite<boost::phoenix::detail::function_eval<1>, boost::fusion::vector<boost::phoenix::value<get0_>, boost::phoenix::argument<0>, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> >, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_> >]
This is with g++ 4.3.2 on Fedora 10. So is this a bug? Can someone suggest a workaround to get it working? Thanks, Manjunath