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 T> constexpr bool operator< (const optional<T>& x, const optional<T>& y);
14
15 #include <experimental/optional>
16
17 using std::experimental::optional;
18
19 struct X
20 {
21 int i_;
22
XX23 constexpr X(int i) : i_(i) {}
24 };
25
operator <(const X & lhs,const X & rhs)26 constexpr bool operator < ( const X &lhs, const X &rhs )
27 { return lhs.i_ < rhs.i_ ; }
28
main()29 int main()
30 {
31 {
32 typedef optional<X> O;
33
34 constexpr O o1; // disengaged
35 constexpr O o2; // disengaged
36 constexpr O o3{1}; // engaged
37 constexpr O o4{2}; // engaged
38 constexpr O o5{1}; // engaged
39
40 static_assert ( !(o1 < o1), "" );
41 static_assert ( !(o1 < o2), "" );
42 static_assert ( (o1 < o3), "" );
43 static_assert ( (o1 < o4), "" );
44 static_assert ( (o1 < o5), "" );
45
46 static_assert ( !(o2 < o1), "" );
47 static_assert ( !(o2 < o2), "" );
48 static_assert ( (o2 < o3), "" );
49 static_assert ( (o2 < o4), "" );
50 static_assert ( (o2 < o5), "" );
51
52 static_assert ( !(o3 < o1), "" );
53 static_assert ( !(o3 < o2), "" );
54 static_assert ( !(o3 < o3), "" );
55 static_assert ( (o3 < o4), "" );
56 static_assert ( !(o3 < o5), "" );
57
58 static_assert ( !(o4 < o1), "" );
59 static_assert ( !(o4 < o2), "" );
60 static_assert ( !(o4 < o3), "" );
61 static_assert ( !(o4 < o4), "" );
62 static_assert ( !(o4 < o5), "" );
63
64 static_assert ( !(o5 < o1), "" );
65 static_assert ( !(o5 < o2), "" );
66 static_assert ( !(o5 < o3), "" );
67 static_assert ( (o5 < o4), "" );
68 static_assert ( !(o5 < o5), "" );
69 }
70 }
71