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 // UNSUPPORTED: libcpp-has-no-incomplete-ranges
11
12 // friend constexpr bool operator==(const inner-iterator& x, const inner-iterator& y);
13 // requires forward_range<Base>;
14 //
15 // friend constexpr bool operator==(const inner-iterator& x, default_sentinel_t);
16
17 #include <ranges>
18
19 #include <concepts>
20 #include <string_view>
21 #include "../types.h"
22
23 template <class Iter>
24 concept CanCallEquals = requires(const Iter& i) {
25 i == i;
26 i != i;
27 };
28
test()29 constexpr bool test() {
30 // When `View` is a forward range, `inner-iterator` supports both overloads of `operator==`.
31 {
32 SplitViewForward v("abc def", " ");
33 auto val = *v.begin();
34 auto b = val.begin();
35 std::same_as<std::default_sentinel_t> decltype(auto) e = val.end();
36
37 // inner-iterator == inner-iterator
38 {
39 assert(b == b);
40 assert(!(b != b));
41 }
42
43 // inner-iterator == default_sentinel
44 {
45 assert(!(b == e));
46 assert(b != e);
47
48 assert(!(b == std::default_sentinel));
49 assert(b != std::default_sentinel);
50 }
51 }
52
53 // When `View` is an input range, `inner-iterator only supports comparing an `inner-iterator` to the default sentinel.
54 {
55 SplitViewInput v("abc def", ' ');
56 auto val = *v.begin();
57 auto b = val.begin();
58 std::same_as<std::default_sentinel_t> decltype(auto) e = val.end();
59
60 static_assert(!CanCallEquals<decltype(b)>);
61
62 assert(!(b == std::default_sentinel));
63 assert(b != std::default_sentinel);
64 assert(!(b == e));
65 assert(b != e);
66 }
67
68 return true;
69 }
70
main(int,char **)71 int main(int, char**) {
72 test();
73 static_assert(test());
74
75 return 0;
76 }
77