clang/test/SemaTemplate/alignas.cpp

   1 // RUN: %clang_cc1 -std=c++11 -verify %s
   2
   3 // expected-no-diagnostics
   4 using size_t = decltype(sizeof(0));
   5
   6 template<typename T, typename U>
   7 constexpr T max(T t, U u) { return t > u ? t : u; }
   8
   9 template<typename T, typename ...Ts>
  10 constexpr auto max(T t, Ts ...ts) -> decltype(max(t, max(ts...))) {
  11   return max(t, max(ts...));
  12 }
  13
  14 template<typename...T> struct my_union {
  15   alignas(T...) char buffer[max(sizeof(T)...)];
  16 };
  17
  18 struct alignas(8) A { char c; };
  19 struct alignas(4) B { short s; };
  20 struct C { char a[16]; };
  21
  22 static_assert(sizeof(my_union<A, B, C>) == 16, "");
  23 static_assert(alignof(my_union<A, B, C>) == 8, "");
  24
  25 namespace PR35028 {
  26   template<class X, int Alignment> struct alignas(X) alignas(long long) alignas(long double) alignas(Alignment) Aligned {
  27     union {
  28       long long align1;
  29       long double align2;
  30       char data[sizeof(X)];
  31     };
  32   };
  33   Aligned<int, 1> a;
  34 }