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 // <optional>
11
12 // template <class U>
13 // optional(optional<U>&& rhs);
14
15 #include <cassert>
16 #include <memory>
17 #include <optional>
18 #include <type_traits>
19 #include <utility>
20
21 #include "test_macros.h"
22
23 using std::optional;
24
25 template <class T, class U>
26 TEST_CONSTEXPR_CXX20 void
test(optional<U> && rhs,bool is_going_to_throw=false)27 test(optional<U>&& rhs, bool is_going_to_throw = false)
28 {
29 bool rhs_engaged = static_cast<bool>(rhs);
30 #ifndef TEST_HAS_NO_EXCEPTIONS
31 try
32 {
33 optional<T> lhs = std::move(rhs);
34 assert(is_going_to_throw == false);
35 assert(static_cast<bool>(lhs) == rhs_engaged);
36 }
37 catch (int i)
38 {
39 assert(i == 6);
40 }
41 #else
42 if (is_going_to_throw) return;
43 optional<T> lhs = std::move(rhs);
44 assert(static_cast<bool>(lhs) == rhs_engaged);
45 #endif
46 }
47
48 class X
49 {
50 int i_;
51 public:
X(int i)52 TEST_CONSTEXPR_CXX20 X(int i) : i_(i) {}
X(X && x)53 TEST_CONSTEXPR_CXX20 X(X&& x) : i_(std::exchange(x.i_, 0)) {}
~X()54 TEST_CONSTEXPR_CXX20 ~X() {i_ = 0;}
operator ==(const X & x,const X & y)55 friend constexpr bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
56 };
57
58 struct Z
59 {
ZZ60 Z(int) { TEST_THROW(6); }
61 };
62
63 template<class T, class U>
test_all()64 TEST_CONSTEXPR_CXX20 bool test_all()
65 {
66 {
67 optional<T> rhs;
68 test<U>(std::move(rhs));
69 }
70 {
71 optional<T> rhs(short{3});
72 test<U>(std::move(rhs));
73 }
74 return true;
75 }
76
main(int,char **)77 int main(int, char**)
78 {
79 test_all<short, int>();
80 test_all<int, X>();
81 #if TEST_STD_VER > 17
82 static_assert(test_all<short, int>());
83 static_assert(test_all<int, X>());
84 #endif
85 {
86 optional<int> rhs;
87 test<Z>(std::move(rhs));
88 }
89 {
90 optional<int> rhs(3);
91 test<Z>(std::move(rhs), true);
92 }
93
94 static_assert(!(std::is_constructible<optional<X>, optional<Z>>::value), "");
95
96 return 0;
97 }
98