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// <optional>
12
13// void reset() noexcept;
14
15#include <optional>
16#include <type_traits>
17#include <cassert>
18
19#include "test_macros.h"
20
21using std::optional;
22
23struct X
24{
25 static bool dtor_called;
26 X() = default;
27 X(const X&) = default;
28 X& operator=(const X&) = default;
29 ~X() {dtor_called = true;}
30};
31
32bool X::dtor_called = false;
33
34TEST_CONSTEXPR_CXX20 bool check_reset() {
35 {
36 optional<int> opt;
37 static_assert(noexcept(opt.reset()) == true, "");
38 opt.reset();
39 assert(static_cast<bool>(opt) == false);
40 }
41 {
42 optional<int> opt(3);
43 opt.reset();
44 assert(static_cast<bool>(opt) == false);
45 }
46 return true;
47}
48
49int main(int, char**)
50{
51 check_reset();
52#if TEST_STD_VER >= 20
53 static_assert(check_reset());
54#endif
55 {
56 optional<X> opt;
57 static_assert(noexcept(opt.reset()) == true, "");
58 assert(X::dtor_called == false);
59 opt.reset();
60 assert(X::dtor_called == false);
61 assert(static_cast<bool>(opt) == false);
62 }
63 {
64 optional<X> opt(X{});
65 X::dtor_called = false;
66 opt.reset();
67 assert(X::dtor_called == true);
68 assert(static_cast<bool>(opt) == false);
69 X::dtor_called = false;
70 }
71
72 return 0;
73}
74

source code of libcxx/test/std/utilities/optional/optional.object/optional.object.mod/reset.pass.cpp