1 // RUN: %clang_cc1 -verify -std=c++11 %s 2 3 // Unlike in C++98, C++11 allows unions to have static data members. 4 5 union U1 { 6 static constexpr int k1 = 0; 7 static const int k2 = k1; 8 static int k3 = k2; // expected-error {{non-const static data member must be initialized out of line}} 9 static constexpr double k4 = k2; 10 static const double k5 = k4; // expected-warning {{GNU extension}} expected-note {{use 'constexpr'}} 11 int n[k1 + 3]; 12 }; 13 14 constexpr int U1::k1; 15 constexpr int U1::k2; 16 int U1::k3; 17 18 const double U1::k4; 19 const double U1::k5; 20 21 template<typename T> 22 union U2 { 23 static const int k1; 24 static double k2; 25 T t; 26 }; 27 template<typename T> constexpr int U2<T>::k1 = sizeof(U2<T>); 28 template<typename T> double U2<T>::k2 = 5.3; 29 30 static_assert(U2<int>::k1 == sizeof(int), ""); 31 static_assert(U2<char>::k1 == sizeof(char), ""); 32 33 union U3 { 34 static const int k; 35 U3() : k(0) {} // expected-error {{does not name a non-static data member}} 36 }; 37 38 struct S { 39 union { 40 static const int n; // expected-error {{static members cannot be declared in an anonymous union}} 41 int a; 42 int b; 43 }; 44 }; 45 static union { 46 static const int k; // expected-error {{static members cannot be declared in an anonymous union}} 47 int n; 48 }; 49