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
10 
11 // <tuple>
12 
13 // template <class... Types> class tuple;
14 
15 // ~tuple();
16 
17 // C++17 added:
18 //   The destructor of tuple shall be a trivial destructor
19 //     if (is_trivially_destructible_v<Types> && ...) is true.
20 
21 #include <tuple>
22 #include <string>
23 #include <cassert>
24 #include <type_traits>
25 
26 #include "test_macros.h"
27 
28 struct TrackDtor {
29    int* count_;
30    constexpr explicit TrackDtor(int* count) : count_(count) {}
31    TEST_CONSTEXPR_CXX14 TrackDtor(TrackDtor&& that) : count_(that.count_) { that.count_ = nullptr; }
32    TEST_CONSTEXPR_CXX20 ~TrackDtor() { if(count_) ++*count_; }
33 };
34 static_assert(!std::is_trivially_destructible<TrackDtor>::value, "");
35 
36 static_assert(std::is_trivially_destructible<std::tuple<>>::value, "");
37 static_assert(std::is_trivially_destructible<std::tuple<void*>>::value, "");
38 static_assert(std::is_trivially_destructible<std::tuple<int, float>>::value, "");
39 static_assert(!std::is_trivially_destructible<std::tuple<std::string>>::value, "");
40 static_assert(!std::is_trivially_destructible<std::tuple<int, std::string>>::value, "");
41 
42 TEST_CONSTEXPR_CXX20 bool test() {
43   int count = 0;
44   {
45     std::tuple<TrackDtor> tuple{TrackDtor(&count)};
46     assert(count == 0);
47   }
48   assert(count == 1);
49 
50   return true;
51 }
52 
53 int main(int, char**)
54 {
55   test();
56 #if TEST_STD_VER > 17
57   static_assert(test());
58 #endif
59 
60   return 0;
61 }
62