1 files changed, 120 insertions, 0 deletions
diff --git a/src/boost/libs/hana/test/tuple/cnstr.trap.cpp b/src/boost/libs/hana/test/tuple/cnstr.trap.cpp
new file mode 100644
index 000000000..a088b9466
--- /dev/null
+++ b/src/boost/libs/hana/test/tuple/cnstr.trap.cpp
@@ -0,0 +1,120 @@
+// Copyright Louis Dionne 2013-2017
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
+
+#include <boost/hana/tuple.hpp>
+
+#include <utility>
+namespace hana = boost::hana;
+
+
+// Make sure that the tuple(Yn&&...) is not preferred over copy constructors
+// in single-element cases and other similar cases.
+
+struct Trap1 {
+    Trap1() = default;
+    Trap1(Trap1 const&) = default;
+#ifndef BOOST_HANA_WORKAROUND_MSVC_MULTIPLECTOR_106654
+    Trap1(Trap1&) = default;
+#endif
+    Trap1(Trap1&&) = default;
+
+    template <typename X>
+    Trap1(X&&) {
+        static_assert(sizeof(X) && false,
+        "this constructor must not be instantiated");
+    }
+};
+
+struct Trap2 {
+    Trap2() = default;
+    Trap2(Trap2 const&) = default;
+#ifndef BOOST_HANA_WORKAROUND_MSVC_MULTIPLECTOR_106654
+    Trap2(Trap2&) = default;
+#endif
+    Trap2(Trap2&&) = default;
+
+    template <typename X>
+    Trap2(X) { // not by reference
+        static_assert(sizeof(X) && false,
+        "this constructor must not be instantiated");
+    }
+};
+
+struct Trap3 {
+    Trap3() = default;
+    Trap3(Trap3 const&) = default;
+#ifndef BOOST_HANA_WORKAROUND_MSVC_MULTIPLECTOR_106654
+    Trap3(Trap3&) = default;
+#endif
+    Trap3(Trap3&&) = default;
+
+    template <typename X>
+    constexpr explicit Trap3(X&&) { // explicit, and constexpr
+        static_assert(sizeof(X) && false,
+        "this constructor must not be instantiated");
+    }
+};
+
+struct Trap4 {
+    Trap4() = default;
+    template <typename Args>
+    constexpr explicit Trap4(Args&&) {
+        static_assert(sizeof(Args) && false, "must never be instantiated");
+    }
+
+    Trap4(Trap4 const&) = default;
+    Trap4(Trap4&&) = default;
+};
+
+int main() {
+    {
+        hana::tuple<Trap1> tuple{};
+        hana::tuple<Trap1> implicit_copy = tuple;
+        hana::tuple<Trap1> explicit_copy(tuple);
+        hana::tuple<Trap1> implicit_move = std::move(tuple);
+        hana::tuple<Trap1> explicit_move(std::move(tuple));
+
+        (void)implicit_copy;
+        (void)explicit_copy;
+        (void)implicit_move;
+        (void)explicit_move;
+    }
+
+    {
+        hana::tuple<Trap2> tuple{};
+        hana::tuple<Trap2> implicit_copy = tuple;
+        hana::tuple<Trap2> explicit_copy(tuple);
+        hana::tuple<Trap2> implicit_move = std::move(tuple);
+        hana::tuple<Trap2> explicit_move(std::move(tuple));
+
+        (void)implicit_copy;
+        (void)explicit_copy;
+        (void)implicit_move;
+        (void)explicit_move;
+    }
+
+    {
+        hana::tuple<Trap3> tuple{};
+        hana::tuple<Trap3> implicit_copy = tuple;
+        hana::tuple<Trap3> explicit_copy(tuple);
+        hana::tuple<Trap3> implicit_move = std::move(tuple);
+        hana::tuple<Trap3> explicit_move(std::move(tuple));
+
+        (void)implicit_copy;
+        (void)explicit_copy;
+        (void)implicit_move;
+        (void)explicit_move;
+    }
+
+    // Just defining the structure used to cause a failure, because of the
+    // explicitly defaulted copy-constructor.
+    {
+        struct Foo {
+            Foo() = default;
+            Foo(Foo const&) = default;
+            Foo(Foo&&) = default;
+            hana::tuple<Trap4> t;
+        };
+    }
+}