1 // PR c++/99650
2 // { dg-do compile { target c++17 } }
3 
4 namespace std {
5   template<typename T> struct tuple_size;
6   template<int, typename> struct tuple_element;
7 }
8 
9 struct A {
10   int i;
getA11   template <int I> void get() { }
12 };
13 
14 template<> struct std::tuple_size<A> { static const int value = 2; };
15 template<int I> struct std::tuple_element<I,A> { using type = void; };
16 
17 A a = { 42 };
18 auto [ x, y ] = a;	// { dg-error ".std::tuple_element<0, A>::type. is .void." }
19 // { dg-message "in initialization of structured binding variable 'x'" "" { target *-*-* } .-1 }
20