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
27template <class T, std::size_t N, class U, std::size_t idx>
28void 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
44int 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

source code of libcxx/test/std/utilities/tuple/tuple.tuple/tuple.helper/tuple.include.array.pass.cpp