#include <boost/variant.hpp> #include <boost/multi_array.hpp> typedef boost::variant< double, std::string > Variant_t; typedef boost::multi_array<Variant_t, 2> Array2d_t; typedef boost::multi_array<Variant_t, 1> Array1d_t; // not sure if this is even legal int main () { Array2d_t A(boost::extents[3][4]); for(Array2d_t::iterator i = A.begin(); i != A.end(); ++i) for(Array1d_t::iterator j = i->begin(); j != i->end(); ++j) *j=Variant_t(1.1); return 0; } boost 1.31.1 and multi_array for variants for g++ (GCC) 3.2.3 20030502 (Red Hat Linux 3.2.3-42): No Errors g++ (GCC) 3.4.3 20050227 (Red Hat 3.4.3-22.1) /local/boost/1.33.1/common/include/boost-1_33_1/boost/iterator/iterator_facade.hpp: In function `typename boost::detail::enable_if_interoperable<Derived1, Derived2, typename boost::mpl::apply2<boost::detail::always_bool2, Derived1, Derived2>::type>::type boost::operator!=(const boost::iterator_facade<Derived1, V1, TC1, R1, D1>&, const boost::iterator_facade<Derived2, V2, TC2, R2, D2>&) [with Derived1 = boost::detail::multi_array::array_iterator<Variant_t, Variant_t*, mpl_::size_t<2u>, boost::detail::multi_array::sub_array<Variant_t, 1u> >, V1 = boost::multi_array<Variant_t, 1u, std::allocator<Variant_t> >, TC1 = boost::random_access_traversal_tag, R1 = boost::detail::multi_array::sub_array<Variant_t, 1u>, D1 = ptrdiff_t, Derived2 = boost::detail::multi_array::array_iterator<Variant_t, Variant_t*, mpl_::size_t<2u>, boost::detail::multi_array::sub_array<Variant_t, 1u> >, V2 = boost::multi_array<Variant_t, 1u, std::allocator<Variant_t> >, TC2 = boost::random_access_traversal_tag, R2 = boost::detail::multi_array::sub_array<Variant_t, 1u>, D2 = ptrdiff_t]': multi.cc:12: instantiated from here /local/boost/1.33.1/common/include/boost-1_33_1/boost/iterator/iterator_facade.hpp:840: error: dependent-name ` boost::is_convertible<Derived2,Derived1>::type' is parsed as a non-type, but instantiation yields a type /local/boost/1.33.1/common/include/boost-1_33_1/boost/iterator/iterator_facade.hpp:840: note: say `typename boost::is_convertible<Derived2,Derived1>::type' if a type is meant /local/boost/1.33.1/common/include/boost-1_33_1/boost/iterator/iterator_facade.hpp: In function `typename boost::detail::enable_if_interoperable<Derived1, Derived2, typename boost::mpl::apply2<boost::detail::always_bool2, Derived1, Derived2>::type>::type boost::operator!=(const boost::iterator_facade<Derived1, V1, TC1, R1, D1>&, const boost::iterator_facade<Derived2, V2, TC2, R2, D2>&) [with Derived1 = boost::detail::multi_array::array_iterator<Variant_t, Variant_t*, mpl_::size_t<1u>, Variant_t&>, V1 = Variant_t, TC1 = boost::random_access_traversal_tag, R1 = Variant_t&, D1 = ptrdiff_t, Derived2 = boost::detail::multi_array::array_iterator<Variant_t, Variant_t*, mpl_::size_t<1u>, Variant_t&>, V2 = Variant_t, TC2 = boost::random_access_traversal_tag, R2 = Variant_t&, D2 = ptrdiff_t]': multi.cc:13: instantiated from here /local/boost/1.33.1/common/include/boost-1_33_1/boost/iterator/iterator_facade.hpp:840: error: dependent-name ` boost::is_convertible<Derived2,Derived1>::type' is parsed as a non-type, but instantiation yields a type /local/boost/1.33.1/common/include/boost-1_33_1/boost/iterator/iterator_facade.hpp:840: note: say `typename boost::is_convertible<Derived2,Derived1>::type' if a type is meant make: *** [multi] Error 1 __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com