1 files changed, 110 insertions, 0 deletions
diff --git a/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/default.pass.cpp b/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/default.pass.cpp
new file mode 100644
index 0000000000000..d282c9c68a42d
--- /dev/null
+++ b/test/std/utilities/tuple/tuple.tuple/tuple.cnstr/default.pass.cpp
@@ -0,0 +1,110 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <tuple>
+
+// template <class... Types> class tuple;
+
+// constexpr tuple();
+
+// UNSUPPORTED: c++98, c++03
+
+#include <tuple>
+#include <string>
+#include <cassert>
+#include <type_traits>
+
+#include "DefaultOnly.h"
+
+struct NoDefault {
+    NoDefault() = delete;
+    explicit NoDefault(int) { }
+};
+
+struct NoExceptDefault {
+    NoExceptDefault() noexcept = default;
+};
+
+struct ThrowingDefault {
+    ThrowingDefault() { }
+};
+
+struct IllFormedDefault {
+    IllFormedDefault(int x) : value(x) {}
+    template <bool Pred = false>
+    constexpr IllFormedDefault() {
+        static_assert(Pred,
+            "The default constructor should not be instantiated");
+    }
+    int value;
+};
+
+int main()
+{
+    {
+        std::tuple<> t;
+    }
+    {
+        std::tuple<int> t;
+        assert(std::get<0>(t) == 0);
+    }
+    {
+        std::tuple<int, char*> t;
+        assert(std::get<0>(t) == 0);
+        assert(std::get<1>(t) == nullptr);
+    }
+    {
+        std::tuple<int, char*, std::string> t;
+        assert(std::get<0>(t) == 0);
+        assert(std::get<1>(t) == nullptr);
+        assert(std::get<2>(t) == "");
+    }
+    {
+        std::tuple<int, char*, std::string, DefaultOnly> t;
+        assert(std::get<0>(t) == 0);
+        assert(std::get<1>(t) == nullptr);
+        assert(std::get<2>(t) == "");
+        assert(std::get<3>(t) == DefaultOnly());
+    }
+    {
+        // See bug #21157.
+        static_assert(!std::is_default_constructible<std::tuple<NoDefault>>(), "");
+        static_assert(!std::is_default_constructible<std::tuple<DefaultOnly, NoDefault>>(), "");
+        static_assert(!std::is_default_constructible<std::tuple<NoDefault, DefaultOnly, NoDefault>>(), "");
+    }
+    {
+        static_assert(noexcept(std::tuple<NoExceptDefault>()), "");
+        static_assert(noexcept(std::tuple<NoExceptDefault, NoExceptDefault>()), "");
+
+        static_assert(!noexcept(std::tuple<ThrowingDefault, NoExceptDefault>()), "");
+        static_assert(!noexcept(std::tuple<NoExceptDefault, ThrowingDefault>()), "");
+        static_assert(!noexcept(std::tuple<ThrowingDefault, ThrowingDefault>()), "");
+    }
+#ifndef _LIBCPP_HAS_NO_CONSTEXPR
+    {
+        constexpr std::tuple<> t;
+    }
+    {
+        constexpr std::tuple<int> t;
+        assert(std::get<0>(t) == 0);
+    }
+    {
+        constexpr std::tuple<int, char*> t;
+        assert(std::get<0>(t) == 0);
+        assert(std::get<1>(t) == nullptr);
+    }
+    {
+    // Check that the SFINAE on the default constructor is not evaluted when
+    // it isn't needed. If the default constructor is evaluted then this test
+    // should fail to compile.
+        IllFormedDefault v(0);
+        std::tuple<IllFormedDefault> t(v);
+    }
+#endif
+}