219   struct B { A a; };  argument
520   template<typename T, unsigned N> struct array {  struct
521     constexpr array() : arr{} {}  in array()  function
523     constexpr array(X ...x) : arr{} {  in array()  function
526     template<int ...I, typename ...X> constexpr void init(ints<I...>, X ...x) {  in init()
529     T arr[N];
530     struct iterator {
537     constexpr iterator begin() { return iterator(arr); }  in begin()
538     constexpr iterator end() { return iterator(arr + N); }  in end()
557     struct B {  struct
558       int k = 1;
559       union U {
563       } u;
575   struct B {  struct
576     bool assigned = false;
577     constexpr B &operator=(const B&) {  in operator =()