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 <class... Types>
15 // class tuple_size<tuple<Types...>>
16 // : public integral_constant<size_t, sizeof...(Types)> { };
17 //
18 // LWG #2212 says that tuple_size and tuple_element must be
19 // available after including <utility>
20
21 #include <cstddef>
22 #include <utility>
23 #include <type_traits>
24
25 template <class T, std::size_t N, class U, size_t idx>
test()26 void test()
27 {
28 static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
29 std::tuple_size<T> >::value), "");
30 static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
31 std::tuple_size<const T> >::value), "");
32 static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
33 std::tuple_size<volatile T> >::value), "");
34 static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
35 std::tuple_size<const volatile T> >::value), "");
36 static_assert((std::is_same<typename std::tuple_element<idx, T>::type, U>::value), "");
37 static_assert((std::is_same<typename std::tuple_element<idx, const T>::type, const U>::value), "");
38 static_assert((std::is_same<typename std::tuple_element<idx, volatile T>::type, volatile U>::value), "");
39 static_assert((std::is_same<typename std::tuple_element<idx, const volatile T>::type, const volatile U>::value), "");
40 }
41
main()42 int main()
43 {
44 test<std::pair<int, int>, 2, int, 0>();
45 test<std::pair<int, int>, 2, int, 1>();
46 test<std::pair<const int, int>, 2, int, 1>();
47 test<std::pair<int, volatile int>, 2, volatile int, 1>();
48 test<std::pair<char *, int>, 2, char *, 0>();
49 test<std::pair<char *, int>, 2, int, 1>();
50 }
51