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
10 
11 // <functional>
12 
13 // ranges::not_equal_to
14 
15 #include <functional>
16 #include <type_traits>
17 #include <cassert>
18 
19 #include "test_macros.h"
20 #include "compare_types.h"
21 #include "MoveOnly.h"
22 #include "pointer_comparison_test_helper.h"
23 
24 struct NotEqualityComparable {
25   friend bool operator==(const NotEqualityComparable&, const NotEqualityComparable&);
26   friend bool operator!=(const NotEqualityComparable&, const NotEqualityComparable&) = delete;
27 };
28 
29 static_assert(!std::is_invocable_v<std::ranges::equal_to, NotEqualityComparable, NotEqualityComparable>);
30 static_assert(!std::is_invocable_v<std::ranges::equal_to, int, MoveOnly>);
31 static_assert(std::is_invocable_v<std::ranges::equal_to, explicit_operators, explicit_operators>);
32 
33 static_assert(requires { typename std::ranges::not_equal_to::is_transparent; });
34 
35 struct PtrAndNotEqOperator {
36   constexpr operator void*() const { return nullptr; }
37   // We *don't* want operator!= to be picked here.
38   friend constexpr bool operator!=(PtrAndNotEqOperator, PtrAndNotEqOperator) { return true; }
39 };
40 
41 constexpr bool test() {
42   auto fn = std::ranges::not_equal_to();
43 
44   assert(fn(MoveOnly(41), MoveOnly(42)));
45 
46   // These are the opposite of other tests.
47   ForwardingTestObject a;
48   ForwardingTestObject b;
49   assert(fn(a, b));
50   assert(!fn(std::move(a), std::move(b)));
51 
52   assert(fn(1, 2));
53   assert(!fn(2, 2));
54   assert(fn(2, 1));
55 
56   assert(fn(2, 1L));
57 
58   // Make sure that "ranges::equal_to(x, y) == !ranges::not_equal_to(x, y)", even here.
59   assert(!fn(PtrAndNotEqOperator(), PtrAndNotEqOperator()));
60   assert(std::ranges::equal_to()(PtrAndNotEqOperator(), PtrAndNotEqOperator()));
61 
62   return true;
63 }
64 
65 int main(int, char**) {
66 
67   test();
68   static_assert(test());
69 
70   // test total ordering of int* for not_equal_to<int*> and not_equal_to<void>.
71   do_pointer_comparison_test(std::ranges::not_equal_to());
72 
73   return 0;
74 }
75