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 <class... Types>
14 // class tuple_size<tuple<Types...>>
15 // : public integral_constant<size_t, sizeof...(Types)> { };
16 //
17 // LWG #2212 says that tuple_size and tuple_element must be
18 // available after including <utility>
19
20 #include <cstddef>
21 #include <utility>
22 #include <type_traits>
23
24 #include "test_macros.h"
25
26 template <class T, std::size_t N, class U, size_t idx>
test()27 void test()
28 {
29 static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
30 std::tuple_size<T> >::value), "");
31 static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
32 std::tuple_size<const T> >::value), "");
33 static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
34 std::tuple_size<volatile T> >::value), "");
35 static_assert((std::is_base_of<std::integral_constant<std::size_t, N>,
36 std::tuple_size<const volatile T> >::value), "");
37 static_assert((std::is_same<typename std::tuple_element<idx, T>::type, U>::value), "");
38 static_assert((std::is_same<typename std::tuple_element<idx, const T>::type, const U>::value), "");
39 static_assert((std::is_same<typename std::tuple_element<idx, volatile T>::type, volatile U>::value), "");
40 static_assert((std::is_same<typename std::tuple_element<idx, const volatile T>::type, const volatile U>::value), "");
41 }
42
main(int,char **)43 int main(int, char**)
44 {
45 test<std::pair<int, int>, 2, int, 0>();
46 test<std::pair<int, int>, 2, int, 1>();
47 test<std::pair<const int, int>, 2, int, 1>();
48 test<std::pair<int, volatile int>, 2, volatile int, 1>();
49 test<std::pair<char *, int>, 2, char *, 0>();
50 test<std::pair<char *, int>, 2, int, 1>();
51
52 return 0;
53 }
54