xref: /llvm-project/clang/test/SemaTemplate/alignas.cpp (revision 0228491bda4401b7e03e7ba55d1c98d9832f1fad)
144c247f0SRichard Smith // RUN: %clang_cc1 -std=c++11 -verify %s
244c247f0SRichard Smith 
344c247f0SRichard Smith // expected-no-diagnostics
444c247f0SRichard Smith using size_t = decltype(sizeof(0));
544c247f0SRichard Smith 
644c247f0SRichard Smith template<typename T, typename U>
max(T t,U u)744c247f0SRichard Smith constexpr T max(T t, U u) { return t > u ? t : u; }
844c247f0SRichard Smith 
944c247f0SRichard Smith template<typename T, typename ...Ts>
max(T t,Ts...ts)1044c247f0SRichard Smith constexpr auto max(T t, Ts ...ts) -> decltype(max(t, max(ts...))) {
1144c247f0SRichard Smith   return max(t, max(ts...));
1244c247f0SRichard Smith }
1344c247f0SRichard Smith 
1444c247f0SRichard Smith template<typename...T> struct my_union {
1544c247f0SRichard Smith   alignas(T...) char buffer[max(sizeof(T)...)];
1644c247f0SRichard Smith };
1744c247f0SRichard Smith 
1844c247f0SRichard Smith struct alignas(8) A { char c; };
1944c247f0SRichard Smith struct alignas(4) B { short s; };
2044c247f0SRichard Smith struct C { char a[16]; };
2144c247f0SRichard Smith 
2244c247f0SRichard Smith static_assert(sizeof(my_union<A, B, C>) == 16, "");
2344c247f0SRichard Smith static_assert(alignof(my_union<A, B, C>) == 8, "");
24*0228491bSRichard Smith 
25*0228491bSRichard Smith namespace PR35028 {
26*0228491bSRichard Smith   template<class X, int Alignment> struct alignas(X) alignas(long long) alignas(long double) alignas(Alignment) Aligned {
27*0228491bSRichard Smith     union {
28*0228491bSRichard Smith       long long align1;
29*0228491bSRichard Smith       long double align2;
30*0228491bSRichard Smith       char data[sizeof(X)];
31*0228491bSRichard Smith     };
32*0228491bSRichard Smith   };
33*0228491bSRichard Smith   Aligned<int, 1> a;
34*0228491bSRichard Smith }
35