1 files changed, 146 insertions, 0 deletions
diff --git a/test/std/experimental/utilities/tuple/tuple.apply/large_arity.pass.cpp b/test/std/experimental/utilities/tuple/tuple.apply/large_arity.pass.cpp
new file mode 100644
index 0000000000000..027258ad8d1d9
--- /dev/null
+++ b/test/std/experimental/utilities/tuple/tuple.apply/large_arity.pass.cpp
@@ -0,0 +1,146 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11
+
+// <experimental/tuple>
+
+// template <class F, class T> constexpr decltype(auto) apply(F &&, T &&)
+
+// Stress testing large arities with tuple and array.
+
+#include <experimental/tuple>
+#include <array>
+#include <utility>
+#include <cassert>
+
+////////////////////////////////////////////////////////////////////////////////
+template <class T, std::size_t Dummy = 0>
+struct always_imp
+{
+    typedef T type;
+};
+
+template <class T, std::size_t Dummy = 0>
+using always_t = typename always_imp<T, Dummy>::type;
+
+////////////////////////////////////////////////////////////////////////////////
+template <class Tuple, class Idx>
+struct make_function;
+
+template <class Tp, std::size_t ...Idx>
+struct make_function<Tp, std::integer_sequence<std::size_t, Idx...>>
+{
+    using type = bool (*)(always_t<Tp, Idx>...);
+};
+
+template <class Tp, std::size_t Size>
+using make_function_t = typename make_function<Tp, std::make_index_sequence<Size>>::type;
+
+////////////////////////////////////////////////////////////////////////////////
+template <class Tp, class Idx>
+struct make_tuple_imp;
+
+////////////////////////////////////////////////////////////////////////////////
+template <class Tp, std::size_t ...Idx>
+struct make_tuple_imp<Tp, std::integer_sequence<std::size_t, Idx...>>
+{
+    using type = std::tuple<always_t<Tp, Idx>...>;
+};
+
+template <class Tp, std::size_t Size>
+using make_tuple_t = typename make_tuple_imp<Tp, std::make_index_sequence<Size>>::type;
+
+template <class ...Types>
+bool test_apply_fn(Types...) { return true; }
+
+namespace ex = std::experimental;
+
+template <std::size_t Size>
+void test_all()
+{
+
+    using A = std::array<int, Size>;
+    using ConstA = std::array<int const, Size>;
+
+    using Tuple = make_tuple_t<int, Size>;
+    using CTuple = make_tuple_t<const int, Size>;
+
+    using ValFn  = make_function_t<int, Size>;
+    ValFn val_fn = &test_apply_fn;
+
+    using RefFn  = make_function_t<int &, Size>;
+    RefFn ref_fn = &test_apply_fn;
+
+    using CRefFn = make_function_t<int const &, Size>;
+    CRefFn cref_fn = &test_apply_fn;
+
+    using RRefFn = make_function_t<int &&, Size>;
+    RRefFn rref_fn = &test_apply_fn;
+
+    {
+        A a{};
+        assert(ex::apply(val_fn, a));
+        assert(ex::apply(ref_fn, a));
+        assert(ex::apply(cref_fn, a));
+        assert(ex::apply(rref_fn, std::move(a)));
+    }
+    {
+        ConstA a{};
+        assert(ex::apply(val_fn, a));
+        assert(ex::apply(cref_fn, a));
+    }
+    {
+        Tuple a{};
+        assert(ex::apply(val_fn, a));
+        assert(ex::apply(ref_fn, a));
+        assert(ex::apply(cref_fn, a));
+        assert(ex::apply(rref_fn, std::move(a)));
+    }
+    {
+        CTuple a{};
+        assert(ex::apply(val_fn, a));
+        assert(ex::apply(cref_fn, a));
+    }
+
+}
+
+
+template <std::size_t Size>
+void test_one()
+{
+    using A = std::array<int, Size>;
+    using Tuple = make_tuple_t<int, Size>;
+
+    using ValFn  = make_function_t<int, Size>;
+    ValFn val_fn = &test_apply_fn;
+
+    {
+        A a{};
+        assert(ex::apply(val_fn, a));
+    }
+    {
+        Tuple a{};
+        assert(ex::apply(val_fn, a));
+    }
+}
+
+int main()
+{
+    // Instantiate with 1-5 arguments.
+    test_all<1>();
+    test_all<2>();
+    test_all<3>();
+    test_all<4>();
+    test_all<5>();
+
+    // Stress test with 128.
+    test_one<128>();
+    //test_one<256>();
+}