1 //===----------------------------------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 // UNSUPPORTED: c++98, c++03, c++11, c++14
11 // <optional>
12
13 // template <class U>
14 // optional(optional<U>&& rhs);
15
16 #include <optional>
17 #include <type_traits>
18 #include <memory>
19 #include <cassert>
20
21 #include "test_macros.h"
22
23 using std::optional;
24
25 template <class T, class U>
26 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 X(int i) : i_(i) {}
X(X && x)53 X(X&& x) : i_(std::exchange(x.i_, 0)) {}
~X()54 ~X() {i_ = 0;}
operator ==(const X & x,const X & y)55 friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
56 };
57
58 int count = 0;
59
60 struct Z
61 {
ZZ62 Z(int) { TEST_THROW(6); }
63 };
64
main()65 int main()
66 {
67 {
68 optional<short> rhs;
69 test<int>(std::move(rhs));
70 }
71 {
72 optional<short> rhs(short{3});
73 test<int>(std::move(rhs));
74 }
75 {
76 optional<int> rhs;
77 test<X>(std::move(rhs));
78 }
79 {
80 optional<int> rhs(3);
81 test<X>(std::move(rhs));
82 }
83 {
84 optional<int> rhs;
85 test<Z>(std::move(rhs));
86 }
87 {
88 optional<int> rhs(3);
89 test<Z>(std::move(rhs), true);
90 }
91
92 static_assert(!(std::is_constructible<optional<X>, optional<Z>>::value), "");
93 }
94