Add tests for libc++'s constexpr variant copy/move extension

llvm-svn: 288536

1 files changed, 23 insertions, 0 deletions

diff --git a/libcxx/test/std/utilities/variant/variant.variant/variant.ctor/move.pass.cpp b/libcxx/test/std/utilities/variant/variant.variant/variant.ctor/move.pass.cpp
index dcc973f074f..2a87f32ef9a 100644
--- a/libcxx/test/std/utilities/variant/variant.variant/variant.ctor/move.pass.cpp
+++ b/libcxx/test/std/utilities/variant/variant.variant/variant.ctor/move.pass.cpp
@@ -166,9 +166,32 @@ void test_move_ctor_valueless_by_exception() {
 #endif
 }
 
+template <size_t Idx>
+constexpr bool test_constexpr_ctor_extension_imp(
+    std::variant<long, void*, const int> const& v)
+{
+  auto copy = v;
+  auto v2 = std::move(copy);
+  return v2.index() == v.index() &&
+         v2.index() == Idx &&
+        std::get<Idx>(v2) == std::get<Idx>(v);
+}
+
+void test_constexpr_move_ctor_extension() {
+#ifdef _LIBCPP_VERSION
+  using V = std::variant<long, void*, const int>;
+  static_assert(std::is_trivially_copyable<V>::value, "");
+  static_assert(std::is_trivially_move_constructible<V>::value, "");
+  static_assert(test_constexpr_ctor_extension_imp<0>(V(42l)), "");
+  static_assert(test_constexpr_ctor_extension_imp<1>(V(nullptr)), "");
+  static_assert(test_constexpr_ctor_extension_imp<2>(V(101)), "");
+#endif
+}
+
 int main() {
   test_move_ctor_basic();
   test_move_ctor_valueless_by_exception();
   test_move_noexcept();
   test_move_ctor_sfinae();
+  test_constexpr_move_ctor_extension();
 }