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
11 // <optional>
12
13 // template <class U> optional<T>& operator=(U&& v);
14
15 #include <experimental/optional>
16 #include <type_traits>
17 #include <cassert>
18 #include <memory>
19
20 using std::experimental::optional;
21
22 struct AllowConstAssign {
AllowConstAssignAllowConstAssign23 AllowConstAssign() {}
AllowConstAssignAllowConstAssign24 AllowConstAssign(AllowConstAssign const&) {}
operator =AllowConstAssign25 AllowConstAssign const& operator=(AllowConstAssign const&) const {
26 return *this;
27 }
28 };
29
30 struct X
31 {
32 };
33
main()34 int main()
35 {
36 static_assert(std::is_assignable<optional<int>, int>::value, "");
37 static_assert(std::is_assignable<optional<int>, int&>::value, "");
38 static_assert(std::is_assignable<optional<int>&, int>::value, "");
39 static_assert(std::is_assignable<optional<int>&, int&>::value, "");
40 static_assert(std::is_assignable<optional<int>&, const int&>::value, "");
41 static_assert(!std::is_assignable<const optional<int>&, const int&>::value, "");
42 static_assert(!std::is_assignable<optional<int>, X>::value, "");
43 {
44 optional<int> opt;
45 opt = 1;
46 assert(static_cast<bool>(opt) == true);
47 assert(*opt == 1);
48 }
49 {
50 optional<int> opt;
51 const int i = 2;
52 opt = i;
53 assert(static_cast<bool>(opt) == true);
54 assert(*opt == i);
55 }
56 {
57 optional<int> opt(3);
58 const int i = 2;
59 opt = i;
60 assert(static_cast<bool>(opt) == true);
61 assert(*opt == i);
62 }
63 {
64 optional<const AllowConstAssign> opt;
65 const AllowConstAssign other;
66 opt = other;
67 }
68 {
69 optional<std::unique_ptr<int>> opt;
70 opt = std::unique_ptr<int>(new int(3));
71 assert(static_cast<bool>(opt) == true);
72 assert(**opt == 3);
73 }
74 {
75 optional<std::unique_ptr<int>> opt(std::unique_ptr<int>(new int(2)));
76 opt = std::unique_ptr<int>(new int(3));
77 assert(static_cast<bool>(opt) == true);
78 assert(**opt == 3);
79 }
80 }
81