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) {
28   return lhs.i_ == rhs.i_;
29 }
30 
31 int main(int, char**) {
32   {
33     typedef X T;
34     typedef optional<T> O;
35 
36     constexpr T val(2);
37     constexpr O o1;      // disengaged
38     constexpr O o2{1};   // engaged
39     constexpr O o3{val}; // engaged
40 
41     static_assert(!(o1 == T(1)), "");
42     static_assert((o2 == T(1)), "");
43     static_assert(!(o3 == T(1)), "");
44     static_assert((o3 == T(2)), "");
45     static_assert((o3 == val), "");
46 
47     static_assert(!(T(1) == o1), "");
48     static_assert((T(1) == o2), "");
49     static_assert(!(T(1) == o3), "");
50     static_assert((T(2) == o3), "");
51     static_assert((val == o3), "");
52   }
53   {
54     using O = optional<int>;
55     constexpr O o1(42);
56     static_assert(o1 == 42l, "");
57     static_assert(!(101l == o1), "");
58   }
59   {
60     using O = optional<const int>;
61     constexpr O o1(42);
62     static_assert(o1 == 42, "");
63     static_assert(!(101 == o1), "");
64   }
65 
66   return 0;
67 }
68