1 // PR c++/79205 2 // { dg-do compile { target c++11 } } 3 // { dg-options "" } 4 5 template <unsigned long, typename...> struct B; 6 template <unsigned long I, typename H> struct B<I, H> { int b; }; 7 template <typename... E> struct C { B<0, E...> c; C (C &) = default; C (C &&); }; 8 template <typename> struct tuple_size; 9 template <> struct tuple_size<C<int>> { static constexpr int value = 1; }; 10 template <int, typename> struct tuple_element; 11 template <typename H, typename... T> 12 struct tuple_element<0, C<H, T...>> { typedef int type; }; 13 template <int, typename... E> 14 int &&get (C<E...> &&); 15 16 int 17 foo (C<int> t) 18 { 19 auto[x0] = t; // { dg-warning "structured bindings only available with" "" { target c++14_down } } 20 return x0; 21 } 22