Handle alignas(foo...) pack expansions.

llvm-svn: 175875

1 files changed, 23 insertions, 0 deletions

diff --git a/clang/test/SemaTemplate/alignas.cpp b/clang/test/SemaTemplate/alignas.cpp
new file mode 100644
index 00000000000..8a1f96e5bde
--- /dev/null
+++ b/clang/test/SemaTemplate/alignas.cpp
@@ -0,0 +1,23 @@
+// RUN: %clang_cc1 -std=c++11 -verify %s
+
+// expected-no-diagnostics
+using size_t = decltype(sizeof(0));
+
+template<typename T, typename U>
+constexpr T max(T t, U u) { return t > u ? t : u; }
+
+template<typename T, typename ...Ts>
+constexpr auto max(T t, Ts ...ts) -> decltype(max(t, max(ts...))) {
+  return max(t, max(ts...));
+}
+
+template<typename...T> struct my_union {
+  alignas(T...) char buffer[max(sizeof(T)...)];
+};
+
+struct alignas(8) A { char c; };
+struct alignas(4) B { short s; };
+struct C { char a[16]; };
+
+static_assert(sizeof(my_union<A, B, C>) == 16, "");
+static_assert(alignof(my_union<A, B, C>) == 8, "");