Fix for PR 19616: 'tuple_cat of nested tuples fails in noexcept specification'. Thanks to Louis Dionne for the fix.

llvm-svn: 219243

2 files changed, 28 insertions, 1 deletions

diff --git a/libcxx/test/utilities/meta/meta.unary/meta.unary.prop/is_nothrow_constructible.pass.cpp b/libcxx/test/utilities/meta/meta.unary/meta.unary.prop/is_nothrow_constructible.pass.cpp
index 9d3f8298757..fe0b5673bc4 100644
--- a/libcxx/test/utilities/meta/meta.unary/meta.unary.prop/is_nothrow_constructible.pass.cpp
+++ b/libcxx/test/utilities/meta/meta.unary/meta.unary.prop/is_nothrow_constructible.pass.cpp
@@ -76,15 +76,28 @@ struct C
     void operator=(C&);  // not const
 };
 
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+struct Tuple {
+    Tuple(Empty&&) noexcept {}
+};
+#endif
+
 int main()
 {
     test_is_nothrow_constructible<int> ();
     test_is_nothrow_constructible<int, const int&> ();
     test_is_nothrow_constructible<Empty> ();
     test_is_nothrow_constructible<Empty, const Empty&> ();
-
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    test_is_nothrow_constructible<Tuple &&, Empty> (); // See bug #19616.
+#endif
+    
     test_is_not_nothrow_constructible<A, int> ();
     test_is_not_nothrow_constructible<A, int, double> ();
     test_is_not_nothrow_constructible<A> ();
     test_is_not_nothrow_constructible<C> ();
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    static_assert(!std::is_constructible<Tuple&, Empty>::value, "");
+    test_is_not_nothrow_constructible<Tuple &, Empty> (); // See bug #19616.
+#endif
 }
diff --git a/libcxx/test/utilities/tuple/tuple.tuple/tuple.creation/tuple_cat.pass.cpp b/libcxx/test/utilities/tuple/tuple.tuple/tuple.creation/tuple_cat.pass.cpp
index b47842d419c..3fca5738929 100644
--- a/libcxx/test/utilities/tuple/tuple.tuple/tuple.creation/tuple_cat.pass.cpp
+++ b/libcxx/test/utilities/tuple/tuple.tuple/tuple.creation/tuple_cat.pass.cpp
@@ -213,4 +213,18 @@ int main()
         assert(std::get<3>(t3) == 4);
         assert(std::get<4>(t3) == 5);
     }
+    {
+        // See bug #19616.
+        auto t1 = std::tuple_cat(
+            std::make_tuple(std::make_tuple(1)),
+            std::make_tuple()
+        );
+        assert(t1 == std::make_tuple(std::make_tuple(1)));
+
+        auto t2 = std::tuple_cat(
+            std::make_tuple(std::make_tuple(1)),
+            std::make_tuple(std::make_tuple(2))
+        );
+        assert(t2 == std::make_tuple(std::make_tuple(1), std::make_tuple(2)));
+    }
 }