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// UNSUPPORTED: c++03, c++11, c++14
10
11// <tuple>
12
13// template <class T> constexpr size_t tuple_size_v = tuple_size<T>::value;
14
15#include <tuple>
16#include <utility>
17#include <array>
18
19#include "test_macros.h"
20
21template <class Tuple, int Expect>
22void test()
23{
24 static_assert(std::tuple_size_v<Tuple> == Expect, "");
25 static_assert(std::tuple_size_v<Tuple> == std::tuple_size<Tuple>::value, "");
26 static_assert(std::tuple_size_v<Tuple const> == std::tuple_size<Tuple>::value, "");
27 static_assert(std::tuple_size_v<Tuple volatile> == std::tuple_size<Tuple>::value, "");
28 static_assert(std::tuple_size_v<Tuple const volatile> == std::tuple_size<Tuple>::value, "");
29}
30
31int main(int, char**)
32{
33 test<std::tuple<>, 0>();
34
35 test<std::tuple<int>, 1>();
36 test<std::array<int, 1>, 1>();
37
38 test<std::tuple<int, int>, 2>();
39 test<std::pair<int, int>, 2>();
40 test<std::array<int, 2>, 2>();
41
42 test<std::tuple<int, int, int>, 3>();
43 test<std::array<int, 3>, 3>();
44
45 return 0;
46}
47

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