2 files changed, 60 insertions, 2 deletions
diff --git a/libcxx/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/default.fail.cpp b/libcxx/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/default.fail.cpp
new file mode 100644
index 00000000000..616550f60e5
--- /dev/null
+++ b/libcxx/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/default.fail.cpp
@@ -0,0 +1,53 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03
+
+// Before GCC 6, aggregate initialization kicks in.
+// See https://stackoverflow.com/q/41799015/627587.
+// UNSUPPORTED: gcc-5
+
+// <tuple>
+
+// template <class... Types> class tuple;
+
+// explicit(see-below) constexpr tuple();
+
+#include <tuple>
+
+
+struct Implicit {
+    Implicit() = default;
+};
+
+struct Explicit {
+    explicit Explicit() = default;
+};
+
+std::tuple<> test1() { return {}; }
+
+std::tuple<Implicit> test2() { return {}; }
+std::tuple<Explicit> test3() { return {}; } // expected-error 1 {{chosen constructor is explicit in copy-initialization}}
+
+std::tuple<Implicit, Implicit> test4() { return {}; }
+std::tuple<Explicit, Implicit> test5() { return {}; } // expected-error 1 {{chosen constructor is explicit in copy-initialization}}
+std::tuple<Implicit, Explicit> test6() { return {}; } // expected-error 1 {{chosen constructor is explicit in copy-initialization}}
+std::tuple<Explicit, Explicit> test7() { return {}; } // expected-error 1 {{chosen constructor is explicit in copy-initialization}}
+
+std::tuple<Implicit, Implicit, Implicit> test8() { return {}; }
+std::tuple<Implicit, Implicit, Explicit> test9() { return {}; } // expected-error 1 {{chosen constructor is explicit in copy-initialization}}
+std::tuple<Implicit, Explicit, Implicit> test10() { return {}; } // expected-error 1 {{chosen constructor is explicit in copy-initialization}}
+std::tuple<Implicit, Explicit, Explicit> test11() { return {}; } // expected-error 1 {{chosen constructor is explicit in copy-initialization}}
+std::tuple<Explicit, Implicit, Implicit> test12() { return {}; } // expected-error 1 {{chosen constructor is explicit in copy-initialization}}
+std::tuple<Explicit, Implicit, Explicit> test13() { return {}; } // expected-error 1 {{chosen constructor is explicit in copy-initialization}}
+std::tuple<Explicit, Explicit, Implicit> test14() { return {}; } // expected-error 1 {{chosen constructor is explicit in copy-initialization}}
+std::tuple<Explicit, Explicit, Explicit> test15() { return {}; } // expected-error 1 {{chosen constructor is explicit in copy-initialization}}
+
+int main(int, char**) {
+    return 0;
+}
diff --git a/libcxx/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/default.pass.cpp b/libcxx/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/default.pass.cpp
index 46fd35ad4dd..c5b650d79a1 100644
--- a/libcxx/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/default.pass.cpp
+++ b/libcxx/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/default.pass.cpp
@@ -10,7 +10,7 @@
 
 // template <class... Types> class tuple;
 
-// constexpr tuple();
+// explicit(see-below) constexpr tuple();
 
 // UNSUPPORTED: c++98, c++03
 
@@ -107,6 +107,11 @@ int main(int, char**)
         IllFormedDefault v(0);
         std::tuple<IllFormedDefault> t(v);
     }
+    {
+        struct Base { };
+        struct Derived : Base { protected: Derived() = default; };
+        static_assert(!std::is_default_constructible<std::tuple<Derived, int> >::value, "");
+    }
 
-  return 0;
+    return 0;
 }