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, c++17, c++20
10
11// template<class T2, class E2> requires (!is_void_v<T2>)
12// friend constexpr bool operator==(const expected& x, const expected<T2, E2>& y);
13
14#include <cassert>
15#include <concepts>
16#include <expected>
17#include <type_traits>
18#include <utility>
19
20#include "test_macros.h"
21#include "../../types.h"
22
23// Test constraint
24static_assert(!CanCompare<NonComparable, NonComparable>);
25
26static_assert(CanCompare<std::expected<int, int>, std::expected<int, int>>);
27static_assert(CanCompare<std::expected<int, int>, std::expected<short, short>>);
28
29#if TEST_STD_VER >= 26
30// https://wg21.link/P3379R0
31static_assert(!CanCompare<std::expected<int, int>, std::expected<void, int>>);
32static_assert(CanCompare<std::expected<int, int>, std::expected<int, int>>);
33static_assert(!CanCompare<std::expected<NonComparable, int>, std::expected<NonComparable, int>>);
34static_assert(!CanCompare<std::expected<int, NonComparable>, std::expected<int, NonComparable>>);
35static_assert(!CanCompare<std::expected<NonComparable, int>, std::expected<int, NonComparable>>);
36static_assert(!CanCompare<std::expected<int, NonComparable>, std::expected<NonComparable, int>>);
37#else
38// Note this is true because other overloads in expected<non-void> are unconstrained
39static_assert(CanCompare<std::expected<void, int>, std::expected<int, int>>);
40#endif
41constexpr bool test() {
42 // x.has_value() && y.has_value()
43 {
44 const std::expected<int, int> e1(5);
45 const std::expected<int, int> e2(10);
46 const std::expected<int, int> e3(5);
47 assert(e1 != e2);
48 assert(e1 == e3);
49 }
50
51 // !x.has_value() && y.has_value()
52 {
53 const std::expected<int, int> e1(std::unexpect, 5);
54 const std::expected<int, int> e2(10);
55 const std::expected<int, int> e3(5);
56 assert(e1 != e2);
57 assert(e1 != e3);
58 }
59
60 // x.has_value() && !y.has_value()
61 {
62 const std::expected<int, int> e1(5);
63 const std::expected<int, int> e2(std::unexpect, 10);
64 const std::expected<int, int> e3(std::unexpect, 5);
65 assert(e1 != e2);
66 assert(e1 != e3);
67 }
68
69 // !x.has_value() && !y.has_value()
70 {
71 const std::expected<int, int> e1(std::unexpect, 5);
72 const std::expected<int, int> e2(std::unexpect, 10);
73 const std::expected<int, int> e3(std::unexpect, 5);
74 assert(e1 != e2);
75 assert(e1 == e3);
76 }
77
78 return true;
79}
80
81int main(int, char**) {
82 test();
83 static_assert(test());
84 return 0;
85}
86

source code of libcxx/test/std/utilities/expected/expected.expected/equality/equality.other_expected.pass.cpp