Fix various GCC mis-configurations for newer versions.
This patch goes through and enables C++11 and C++14 features for newer GCC's.
The main changes are:
1. Turn on variable templates. (Uses __cpp_variable_templates)
2. Assert atomic<Tp> is trivially copyable (Uses _GNUC_VER >= 501).
3. Turn on trailing return support for GCC. (Uses _GNUC_VER >= 404)
4. XFAIL void_t test for GCC 5.1 and 5.2. Fixed in GCC 6.
llvm-svn: 255585
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 831c1129547c973c59ccb957ed9fe0cf74102477
diff --git a/include/atomic b/include/atomic
index b5d5a27..abec2a0 100644
--- a/include/atomic
+++ b/include/atomic
@@ -552,6 +552,12 @@
namespace __gcc_atomic {
template <typename _Tp>
struct __gcc_atomic_t {
+
+#if _GNUC_VER >= 501
+ static_assert(is_trivially_copyable<_Tp>::value,
+ "std::atomic<Tp> requires that 'Tp' be a trivially copyable type");
+#endif
+
_LIBCPP_INLINE_VISIBILITY
#ifndef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
__gcc_atomic_t() _NOEXCEPT = default;