clang/test/CXX/class/class.union/p2-0x.cpp

   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-error {{requires 'constexpr' specifier}} expected-note {{add '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 data member 'n' not allowed in anonymous union}}
  41     int a;
  42     int b;
  43   };
  44 };
  45 static union {
  46   static const int k; // expected-error {{static data member 'k' not allowed in anonymous union}}
  47   int n;
  48 };