1 // PR c++/58910 2 // { dg-do compile { target c++11 } } 3 4 #include <tuple> 5 6 using namespace std; t1t17struct t1{ constexpr t1(){} }; t2t28struct t2{ constexpr t2(){} }; 9 main()10int main() 11 { 12 constexpr t1 T1; 13 constexpr t2 T2; 14 constexpr tuple<t1,t2> Tup1(T1,T2); 15 constexpr tuple<t1,t1> Tup2(T1,T1); 16 constexpr auto a=get<0>(Tup1 ); //works fine 17 constexpr auto b=get<0>(Tup2 ); // error: 18 //'(const std::_Head_base<0ul, t1, true>*)(& Tup2)' 19 //is not a constant expression constexpr auto b=get<0>(Tup2 ); 20 } 21