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// struct tuple_size<tuple<Types...>>
15// : public integral_constant<size_t, sizeof...(Types)> { };
16
17// UNSUPPORTED: c++03
18
19#include <array>
20#include <tuple>
21#include <type_traits>
22#include <utility>
23
24#include "test_macros.h"
25
26template <class T, std::size_t Size = sizeof(std::tuple_size<T>)>
27constexpr bool is_complete(int) { static_assert(Size > 0, ""); return true; }
28template <class> constexpr bool is_complete(long) { return false; }
29template <class T> constexpr bool is_complete() { return is_complete<T>(0); }
30
31struct Dummy1 {};
32struct Dummy2 {};
33
34namespace std {
35template <> struct tuple_size<Dummy1> : public integral_constant<std::size_t, 0> {};
36}
37
38template <class T>
39void test_complete() {
40 static_assert(is_complete<T>(), "");
41 static_assert(is_complete<const T>(), "");
42 static_assert(is_complete<volatile T>(), "");
43 static_assert(is_complete<const volatile T>(), "");
44}
45
46template <class T>
47void test_incomplete() {
48 static_assert(!is_complete<T>(), "");
49 static_assert(!is_complete<const T>(), "");
50 static_assert(!is_complete<volatile T>(), "");
51 static_assert(!is_complete<const volatile T>(), "");
52}
53
54
55int main(int, char**)
56{
57 test_complete<std::tuple<> >();
58 test_complete<std::tuple<int&> >();
59 test_complete<std::tuple<int&&, int&, void*>>();
60 test_complete<std::pair<int, long> >();
61 test_complete<std::array<int, 5> >();
62 test_complete<Dummy1>();
63
64 test_incomplete<void>();
65 test_incomplete<int>();
66 test_incomplete<std::tuple<int>&>();
67 test_incomplete<Dummy2>();
68
69 return 0;
70}
71

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