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 // friend constexpr bool operator==(const inner-iterator& x, const inner-iterator& y);
12 //   requires forward_range<Base>;
13 //
14 // friend constexpr bool operator==(const inner-iterator& x, default_sentinel_t);
15 
16 #include <ranges>
17 
18 #include <concepts>
19 #include <string_view>
20 
21 #include "../types.h"
22 
23 #include "test_range.h"
24 
test()25 constexpr bool test() {
26   // When `View` is a forward range, `inner-iterator` supports both overloads of `operator==`.
27   {
28     SplitViewForward v("abc def", " ");
29     auto val = *v.begin();
30     auto b = val.begin();
31     std::same_as<std::default_sentinel_t> decltype(auto) e = val.end();
32 
33     // inner-iterator == inner-iterator
34     {
35       assert(b == b);
36       assert(!(b != b));
37     }
38 
39     // inner-iterator == default_sentinel
40     {
41       assert(!(b == e));
42       assert(b != e);
43 
44       assert(!(b == std::default_sentinel));
45       assert(b != std::default_sentinel);
46     }
47   }
48 
49   // When `View` is an input range, `inner-iterator only supports comparing an `inner-iterator` to the default sentinel.
50   {
51     SplitViewInput v("abc def", ' ');
52     auto val = *v.begin();
53     auto b = val.begin();
54     std::same_as<std::default_sentinel_t> decltype(auto) e = val.end();
55 
56     static_assert(!weakly_equality_comparable_with<decltype(b), decltype(b)>);
57 
58     assert(!(b == std::default_sentinel));
59     assert(b != std::default_sentinel);
60     assert(!(b == e));
61     assert(b != e);
62   }
63 
64   return true;
65 }
66 
main(int,char **)67 int main(int, char**) {
68   test();
69   static_assert(test());
70 
71   return 0;
72 }
73