xref: /llvm-project/libcxx/test/std/utilities/variant/variant.variant/variant.dtor/dtor.pass.cpp (revision 52271a5c11f6abde1fa1221db304212b5eb8ec7c)
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 // <variant>
12 
13 // template <class ...Types> class variant;
14 
15 // ~variant();
16 
17 #include <cassert>
18 #include <type_traits>
19 #include <variant>
20 
21 #include "test_macros.h"
22 
23 struct NonTDtor {
24   int* count;
NonTDtorNonTDtor25   constexpr NonTDtor(int* a, int*) : count(a) {}
~NonTDtorNonTDtor26   TEST_CONSTEXPR_CXX20 ~NonTDtor() { ++*count; }
27 };
28 static_assert(!std::is_trivially_destructible<NonTDtor>::value, "");
29 
30 struct NonTDtor1 {
31   int* count;
NonTDtor1NonTDtor132   constexpr NonTDtor1(int*, int* b) : count(b) {}
~NonTDtor1NonTDtor133   TEST_CONSTEXPR_CXX20 ~NonTDtor1() { ++*count; }
34 };
35 static_assert(!std::is_trivially_destructible<NonTDtor1>::value, "");
36 
37 struct TDtor {
38   constexpr TDtor() = default;
TDtorTDtor39   constexpr TDtor(const TDtor&) {} // non-trivial copy
40   TEST_CONSTEXPR_CXX20 ~TDtor() = default;
41 };
42 static_assert(!std::is_trivially_copy_constructible<TDtor>::value, "");
43 static_assert(std::is_trivially_destructible<TDtor>::value, "");
44 
test()45 TEST_CONSTEXPR_CXX20 bool test() {
46   {
47     using V = std::variant<int, long, TDtor>;
48     static_assert(std::is_trivially_destructible<V>::value, "");
49     [[maybe_unused]] V v(std::in_place_index<2>);
50   }
51   {
52     using V = std::variant<NonTDtor, int, NonTDtor1>;
53     static_assert(!std::is_trivially_destructible<V>::value, "");
54     {
55       int count0 = 0;
56       int count1 = 0;
57       {
58         V v(std::in_place_index<0>, &count0, &count1);
59         assert(count0 == 0);
60         assert(count1 == 0);
61       }
62       assert(count0 == 1);
63       assert(count1 == 0);
64     }
65     {
66       int count0 = 0;
67       int count1 = 0;
68       { V v(std::in_place_index<1>); }
69       assert(count0 == 0);
70       assert(count1 == 0);
71     }
72     {
73       int count0 = 0;
74       int count1 = 0;
75       {
76         V v(std::in_place_index<2>, &count0, &count1);
77         assert(count0 == 0);
78         assert(count1 == 0);
79       }
80       assert(count0 == 0);
81       assert(count1 == 1);
82     }
83   }
84 
85   return true;
86 }
87 
main(int,char **)88 int main(int, char**) {
89   test();
90 
91 #if TEST_STD_VER >= 20
92   static_assert(test());
93 #endif
94 
95   return 0;
96 }
97