[libcxx] r220295 - LWG #2212 (not yet adopted) mandates that tuple_size/tuple_element are available if <array> or <utility> are included (not just <tuple>). We already do this. Add some tests to make sure that this remains true.

[Marshall Clow]

Author: marshall
Date: Tue Oct 21 10:05:31 2014
New Revision: 220295

URL: http://llvm.org/viewvc/llvm-project?rev=220295&view=rev
Log:
LWG #2212 (not yet adopted) mandates that tuple_size/tuple_element are available if <array> or <utility> are included (not just <tuple>). We already do this. Add some tests to make sure that this remains true.

Added:
    libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.helper/tuple.include.array.pass.cpp
    libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.helper/tuple.include.utility.pass.cpp

Added: libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.helper/tuple.include.array.pass.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.helper/tuple.include.array.pass.cpp?rev=220295&view=auto
==============================================================================
--- libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.helper/tuple.include.array.pass.cpp (added)
+++ libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.helper/tuple.include.array.pass.cpp Tue Oct 21 10:05:31 2014
@@ -0,0 +1,52 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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;
+
+// template <size_t I, class... Types>
+// class tuple_element<I, tuple<Types...> >
+// {
+// public:
+//     typedef Ti type;
+// };
+//
+//  LWG #2212 says that tuple_size and tuple_element must be 
+//     available after including <utility>
+
+#include <array>
+#include <type_traits>
+
+template <class T, std::size_t N, class U, size_t idx>
+void test()
+{
+    static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
+                                   std::tuple_size<T> >::value), "");
+    static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
+                                   std::tuple_size<const T> >::value), "");
+    static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
+                                   std::tuple_size<volatile T> >::value), "");
+    static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
+                                   std::tuple_size<const volatile T> >::value), "");
+    static_assert((std::is_same<typename std::tuple_element<idx, T>::type, U>::value), "");
+    static_assert((std::is_same<typename std::tuple_element<idx, const T>::type, const U>::value), "");
+    static_assert((std::is_same<typename std::tuple_element<idx, volatile T>::type, volatile U>::value), "");
+    static_assert((std::is_same<typename std::tuple_element<idx, const volatile T>::type, const volatile U>::value), "");
+}
+
+int main()
+{
+    test<std::array<int, 5>, 5, int, 0>();
+    test<std::array<int, 5>, 5, int, 1>();
+    test<std::array<const char *, 4>, 4, const char *, 3>();
+    test<std::array<volatile int, 4>, 4, volatile int, 3>();
+    test<std::array<char *, 3>, 3, char *, 1>();
+    test<std::array<char *, 3>, 3, char *, 2>();
+}

Added: libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.helper/tuple.include.utility.pass.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.helper/tuple.include.utility.pass.cpp?rev=220295&view=auto
==============================================================================
--- libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.helper/tuple.include.utility.pass.cpp (added)
+++ libcxx/trunk/test/utilities/tuple/tuple.tuple/tuple.helper/tuple.include.utility.pass.cpp Tue Oct 21 10:05:31 2014
@@ -0,0 +1,49 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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;
+
+// template <class... Types>
+//   class tuple_size<tuple<Types...>>
+//     : public integral_constant<size_t, sizeof...(Types)> { };
+//
+//  LWG #2212 says that tuple_size and tuple_element must be 
+//     available after including <utility>
+
+#include <utility>
+#include <type_traits>
+
+template <class T, std::size_t N, class U, size_t idx>
+void test()
+{
+    static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
+                                   std::tuple_size<T> >::value), "");
+    static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
+                                   std::tuple_size<const T> >::value), "");
+    static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
+                                   std::tuple_size<volatile T> >::value), "");
+    static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
+                                   std::tuple_size<const volatile T> >::value), "");
+    static_assert((std::is_same<typename std::tuple_element<idx, T>::type, U>::value), "");
+    static_assert((std::is_same<typename std::tuple_element<idx, const T>::type, const U>::value), "");
+    static_assert((std::is_same<typename std::tuple_element<idx, volatile T>::type, volatile U>::value), "");
+    static_assert((std::is_same<typename std::tuple_element<idx, const volatile T>::type, const volatile U>::value), "");
+}
+
+int main()
+{
+    test<std::pair<int, int>, 2, int, 0>();
+    test<std::pair<int, int>, 2, int, 1>();
+    test<std::pair<const int, int>, 2, int, 1>();
+    test<std::pair<int, volatile int>, 2, volatile int, 1>();
+    test<std::pair<char *, int>, 2, char *, 0>();
+    test<std::pair<char *, int>, 2, int,    1>();
+}