1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // <tuple>
11 
12 // template <class... Types> class tuple;
13 
14 // template <size_t I, class... Types>
15 // class tuple_element<I, tuple<Types...> >
16 // {
17 // public:
18 //     typedef Ti type;
19 // };
20 //
21 //  LWG #2212 says that tuple_size and tuple_element must be
22 //     available after including <utility>
23 
24 #include <array>
25 #include <type_traits>
26 
27 template <class T, std::size_t N, class U, size_t idx>
test()28 void test()
29 {
30     static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
31                                    std::tuple_size<T> >::value), "");
32     static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
33                                    std::tuple_size<const T> >::value), "");
34     static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
35                                    std::tuple_size<volatile T> >::value), "");
36     static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
37                                    std::tuple_size<const volatile T> >::value), "");
38     static_assert((std::is_same<typename std::tuple_element<idx, T>::type, U>::value), "");
39     static_assert((std::is_same<typename std::tuple_element<idx, const T>::type, const U>::value), "");
40     static_assert((std::is_same<typename std::tuple_element<idx, volatile T>::type, volatile U>::value), "");
41     static_assert((std::is_same<typename std::tuple_element<idx, const volatile T>::type, const volatile U>::value), "");
42 }
43 
main()44 int main()
45 {
46     test<std::array<int, 5>, 5, int, 0>();
47     test<std::array<int, 5>, 5, int, 1>();
48     test<std::array<const char *, 4>, 4, const char *, 3>();
49     test<std::array<volatile int, 4>, 4, volatile int, 3>();
50     test<std::array<char *, 3>, 3, char *, 1>();
51     test<std::array<char *, 3>, 3, char *, 2>();
52 }
53