Appy constexpr to <memory>. Picked up a few missing noexcepts as well.
llvm-svn: 159902
diff --git a/libcxx/include/tuple b/libcxx/include/tuple
index 9e05759..d2bc21f 100644
--- a/libcxx/include/tuple
+++ b/libcxx/include/tuple
@@ -130,7 +130,11 @@
struct _LIBCPP_VISIBLE allocator_arg_t { };
+#if defined(_LIBCPP_HAS_NO_CONSTEXPR) || defined(_LIBCPP_BUILDING_MEMORY)
extern const allocator_arg_t allocator_arg;
+#else
+constexpr allocator_arg_t allocator_arg = allocator_arg_t();
+#endif
// uses_allocator