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 // LWG #2212 says that tuple_size and tuple_element must be
20 // available after including <utility>
21
22 #include <array>
23 #include <type_traits>
24
25 #include "test_macros.h"
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(int,char **)44 int main(int, char**)
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 return 0;
54 }
55