1 // { dg-do run { target c++17 } }
2
3 // Copyright (C) 2013-2021 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15
16 // You should have received a copy of the GNU General Public License along
17 // with this library; see the file COPYING3. If not see
18 // <http://www.gnu.org/licenses/>.
19
20 #include <optional>
21 #include <testsuite_hooks.h>
22
23 int counter = 0;
24
25 struct mixin_counter
26 {
mixin_countermixin_counter27 mixin_counter() { ++counter; }
mixin_countermixin_counter28 mixin_counter(mixin_counter const&) { ++counter; }
~mixin_countermixin_counter29 ~mixin_counter() { --counter; }
30 };
31
32 struct value_type : private mixin_counter
33 {
34 value_type() = default;
value_typevalue_type35 value_type(int) : state(1) { }
value_typevalue_type36 value_type(std::initializer_list<char>, const char*) : state(2) { }
37 int state = 0;
38 };
39
main()40 int main()
41 {
42 using O = std::optional<value_type>;
43
44 // Check emplace
45
46 {
47 O o;
48 o.emplace();
49 VERIFY( o && o->state == 0 );
50 }
51 {
52 O o { std::in_place, 0 };
53 o.emplace();
54 VERIFY( o && o->state == 0 );
55 }
56
57 {
58 O o;
59 o.emplace(0);
60 VERIFY( o && o->state == 1 );
61 }
62 {
63 O o { std::in_place };
64 o.emplace(0);
65 VERIFY( o && o->state == 1 );
66 }
67
68 {
69 O o;
70 o.emplace({ 'a' }, "");
71 VERIFY( o && o->state == 2 );
72 }
73 {
74 O o { std::in_place };
75 o.emplace({ 'a' }, "");
76 VERIFY( o && o->state == 2 );
77 }
78 {
79 O o;
80 VERIFY(&o.emplace(0) == &*o);
81 VERIFY(&o.emplace({ 'a' }, "") == &*o);
82 }
83
84 static_assert( !std::is_constructible<O, std::initializer_list<int>, int>(), "" );
85
86 VERIFY( counter == 0 );
87 }
88