1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // UNSUPPORTED: c++03, c++11, c++14
10 // <optional>
11 
12 // template <class T, class U> constexpr bool operator<(const optional<T>& x, const U& v);
13 // template <class T, class U> constexpr bool operator<(const U& v, const optional<T>& x);
14 
15 #include <optional>
16 
17 #include "test_macros.h"
18 
19 using std::optional;
20 
21 struct X {
22   int i_;
23 
24   constexpr X(int i) : i_(i) {}
25 };
26 
27 constexpr bool operator<(const X& lhs, const X& rhs) { return lhs.i_ < rhs.i_; }
28 
29 int main(int, char**) {
30   {
31     typedef X T;
32     typedef optional<T> O;
33 
34     constexpr T val(2);
35     constexpr O o1;      // disengaged
36     constexpr O o2{1};   // engaged
37     constexpr O o3{val}; // engaged
38 
39     static_assert((o1 < T(1)), "");
40     static_assert(!(o2 < T(1)), ""); // equal
41     static_assert(!(o3 < T(1)), "");
42     static_assert((o2 < val), "");
43     static_assert(!(o3 < val), ""); // equal
44     static_assert((o3 < T(3)), "");
45 
46     static_assert(!(T(1) < o1), "");
47     static_assert(!(T(1) < o2), ""); // equal
48     static_assert((T(1) < o3), "");
49     static_assert(!(val < o2), "");
50     static_assert(!(val < o3), ""); // equal
51     static_assert(!(T(3) < o3), "");
52   }
53   {
54     using O = optional<int>;
55     constexpr O o1(42);
56     static_assert(o1 < 101l, "");
57     static_assert(!(42l < o1), "");
58   }
59   {
60     using O = optional<const int>;
61     constexpr O o1(42);
62     static_assert(o1 < 101, "");
63     static_assert(!(42 < o1), "");
64   }
65 
66   return 0;
67 }
68