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 // <optional>
11 
12 // template <class T> constexpr bool operator==(const optional<T>& x, const optional<T>& y);
13 
14 #include <experimental/optional>
15 #include <type_traits>
16 #include <cassert>
17 
18 #if _LIBCPP_STD_VER > 11
19 
20 using std::experimental::optional;
21 
22 struct X
23 {
24     int i_;
25 
26     constexpr X(int i) : i_(i) {}
27 };
28 
29 constexpr bool operator == ( const X &lhs, const X &rhs )
30     { return lhs.i_ == rhs.i_ ; }
31 
32 #endif
33 
34 int main()
35 {
36 #if _LIBCPP_STD_VER > 11
37     {
38     typedef X T;
39     typedef optional<T> O;
40 
41     constexpr O o1;     // disengaged
42     constexpr O o2;     // disengaged
43     constexpr O o3{1};  // engaged
44     constexpr O o4{2};  // engaged
45     constexpr O o5{1};  // engaged
46 
47     static_assert (   o1 == o1 , "" );
48     static_assert (   o1 == o2 , "" );
49     static_assert ( !(o1 == o3), "" );
50     static_assert ( !(o1 == o4), "" );
51     static_assert ( !(o1 == o5), "" );
52 
53     static_assert (   o2 == o1 , "" );
54     static_assert (   o2 == o2 , "" );
55     static_assert ( !(o2 == o3), "" );
56     static_assert ( !(o2 == o4), "" );
57     static_assert ( !(o2 == o5), "" );
58 
59     static_assert ( !(o3 == o1), "" );
60     static_assert ( !(o3 == o2), "" );
61     static_assert (   o3 == o3 , "" );
62     static_assert ( !(o3 == o4), "" );
63     static_assert (   o3 == o5 , "" );
64 
65     static_assert ( !(o4 == o1), "" );
66     static_assert ( !(o4 == o2), "" );
67     static_assert ( !(o4 == o3), "" );
68     static_assert (   o4 == o4 , "" );
69     static_assert ( !(o4 == o5), "" );
70 
71     static_assert ( !(o5 == o1), "" );
72     static_assert ( !(o5 == o2), "" );
73     static_assert (   o5 == o3 , "" );
74     static_assert ( !(o5 == o4), "" );
75     static_assert (   o5 == o5 , "" );
76 
77     }
78 #endif
79 }
80