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 optional<U>& y);
13
14#include <optional>
15
16#include "test_macros.h"
17
18using std::optional;
19
20struct X {
21 int i_;
22
23 constexpr X(int i) : i_(i) {}
24};
25
26constexpr bool operator<(const X& lhs, const X& rhs) { return lhs.i_ < rhs.i_; }
27
28int main(int, char**) {
29 {
30 typedef optional<X> O;
31
32 constexpr O o1; // disengaged
33 constexpr O o2; // disengaged
34 constexpr O o3{1}; // engaged
35 constexpr O o4{2}; // engaged
36 constexpr O o5{1}; // engaged
37
38 static_assert(!(o1 < o1), "");
39 static_assert(!(o1 < o2), "");
40 static_assert((o1 < o3), "");
41 static_assert((o1 < o4), "");
42 static_assert((o1 < o5), "");
43
44 static_assert(!(o2 < o1), "");
45 static_assert(!(o2 < o2), "");
46 static_assert((o2 < o3), "");
47 static_assert((o2 < o4), "");
48 static_assert((o2 < o5), "");
49
50 static_assert(!(o3 < o1), "");
51 static_assert(!(o3 < o2), "");
52 static_assert(!(o3 < o3), "");
53 static_assert((o3 < o4), "");
54 static_assert(!(o3 < o5), "");
55
56 static_assert(!(o4 < o1), "");
57 static_assert(!(o4 < o2), "");
58 static_assert(!(o4 < o3), "");
59 static_assert(!(o4 < o4), "");
60 static_assert(!(o4 < o5), "");
61
62 static_assert(!(o5 < o1), "");
63 static_assert(!(o5 < o2), "");
64 static_assert(!(o5 < o3), "");
65 static_assert((o5 < o4), "");
66 static_assert(!(o5 < o5), "");
67 }
68 {
69 using O1 = optional<int>;
70 using O2 = optional<long>;
71 constexpr O1 o1(42);
72 static_assert(o1 < O2(101), "");
73 static_assert(!(O2(101) < o1), "");
74 }
75 {
76 using O1 = optional<int>;
77 using O2 = optional<const int>;
78 constexpr O1 o1(42);
79 static_assert(o1 < O2(101), "");
80 static_assert(!(O2(101) < o1), "");
81 }
82
83 return 0;
84}
85

source code of libcxx/test/std/utilities/optional/optional.relops/less_than.pass.cpp