1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // <tuple>
10 
11 // template <class... Types> class tuple;
12 
13 // template <size_t I, class... Types>
14 // struct tuple_element<I, tuple<Types...> >
15 // {
16 //     typedef Ti type;
17 // };
18 
19 // UNSUPPORTED: c++03
20 
21 #include <tuple>
22 #include <type_traits>
23 
24 #include "test_macros.h"
25 
26 template <class T, std::size_t N, class U>
test()27 void test()
28 {
29     static_assert((std::is_same<typename std::tuple_element<N, T>::type, U>::value), "");
30     static_assert((std::is_same<typename std::tuple_element<N, const T>::type, const U>::value), "");
31     static_assert((std::is_same<typename std::tuple_element<N, volatile T>::type, volatile U>::value), "");
32     static_assert((std::is_same<typename std::tuple_element<N, const volatile T>::type, const volatile U>::value), "");
33 #if TEST_STD_VER > 11
34     static_assert((std::is_same<typename std::tuple_element_t<N, T>, U>::value), "");
35     static_assert((std::is_same<typename std::tuple_element_t<N, const T>, const U>::value), "");
36     static_assert((std::is_same<typename std::tuple_element_t<N, volatile T>, volatile U>::value), "");
37     static_assert((std::is_same<typename std::tuple_element_t<N, const volatile T>, const volatile U>::value), "");
38 #endif
39 }
40 
main(int,char **)41 int main(int, char**)
42 {
43     test<std::tuple<int>, 0, int>();
44     test<std::tuple<char, int>, 0, char>();
45     test<std::tuple<char, int>, 1, int>();
46     test<std::tuple<int*, char, int>, 0, int*>();
47     test<std::tuple<int*, char, int>, 1, char>();
48     test<std::tuple<int*, char, int>, 2, int>();
49 
50   return 0;
51 }
52