less_than.pass.cpp revision 01afa5c6e407e985d9643707d7b7ab1384bd9317 
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 <optional>
15
16#if _LIBCPP_STD_VER > 11
17
18struct X
19{
20    int i_;
21
22    constexpr X(int i) : i_(i) {}
23};
24
25namespace std
26{
27
28template <>
29struct less<X>
30{
31    constexpr
32    bool
33    operator()(const X& x, const X& y) const
34    {
35        return x.i_ < y.i_;
36    }
37};
38
39}
40
41#endif
42
43int main()
44{
45#if _LIBCPP_STD_VER > 11
46    {
47    typedef std::optional<X> O;
48
49    constexpr O o1;     // disengaged
50    constexpr O o2;     // disengaged
51    constexpr O o3{1};  // engaged
52    constexpr O o4{2};  // engaged
53    constexpr O o5{1};  // engaged
54
55    static_assert ( !(o1 < o1), "" );
56    static_assert ( !(o1 < o2), "" );
57    static_assert (   o1 < o3 , "" );
58    static_assert (   o1 < o4 , "" );
59    static_assert (   o1 < o5 , "" );
60
61    static_assert ( !(o2 < o1), "" );
62    static_assert ( !(o2 < o2), "" );
63    static_assert (   o2 < o3 , "" );
64    static_assert (   o2 < o4 , "" );
65    static_assert (   o2 < o5 , "" );
66
67    static_assert ( !(o3 < o1), "" );
68    static_assert ( !(o3 < o2), "" );
69    static_assert ( !(o3 < o3), "" );
70    static_assert (   o3 < o4 , "" );
71    static_assert ( !(o3 < o5), "" );
72
73    static_assert ( !(o4 < o1), "" );
74    static_assert ( !(o4 < o2), "" );
75    static_assert ( !(o4 < o3), "" );
76    static_assert ( !(o4 < o4), "" );
77    static_assert ( !(o4 < o5), "" );
78
79    static_assert ( !(o5 < o1), "" );
80    static_assert ( !(o5 < o2), "" );
81    static_assert ( !(o5 < o3), "" );
82    static_assert (   o5 < o4 , "" );
83    static_assert ( !(o5 < o5), "" );
84    }
85#endif
86}
87