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-no-concepts
11 
12 // template<class I2, sentinel_for<I> S2>
13 //   requires sentinel_for<S, I2>
14 // friend bool operator==(
15 //   const common_iterator& x, const common_iterator<I2, S2>& y);
16 // template<class I2, sentinel_for<I> S2>
17 //   requires sentinel_for<S, I2> && equality_comparable_with<I, I2>
18 // friend bool operator==(
19 //   const common_iterator& x, const common_iterator<I2, S2>& y);
20 
21 #include <iterator>
22 #include <cassert>
23 
24 #include "test_macros.h"
25 #include "types.h"
26 
27 void test() {
28   int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
29 
30   {
31     auto iter1 = simple_iterator<int*>(buffer);
32     auto commonIter1 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(iter1);
33     auto commonSent1 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(sentinel_type<int*>{buffer + 8});
34 
35     const auto commonIter2 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(iter1);
36     const auto commonSent2 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(sentinel_type<int*>{buffer + 8});
37 
38     assert(commonIter1 != commonSent1);
39     assert(commonIter2 != commonSent2);
40     assert(commonSent1 != commonIter1);
41     assert(commonSent2 != commonIter2);
42 
43     for (auto i = 1; commonIter1 != commonSent1; ++i) {
44       assert(*(commonIter1++) == i);
45     }
46     assert(commonIter1 == commonSent1);
47     assert(commonSent1 == commonIter1);
48   }
49   {
50     auto iter1 = value_iterator<int*>(buffer);
51     auto commonIter1 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(iter1);
52     auto commonSent1 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(sentinel_type<int*>{buffer + 8});
53 
54     const auto commonIter2 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(iter1);
55     const auto commonSent2 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(sentinel_type<int*>{buffer + 8});
56 
57     assert(commonIter1 != commonSent1);
58     assert(commonIter2 != commonSent2);
59     assert(commonSent1 != commonIter1);
60     assert(commonSent2 != commonIter2);
61 
62     for (auto i = 1; commonIter1 != commonSent1; ++i) {
63       assert(*(commonIter1++) == i);
64     }
65     assert(commonIter1 == commonSent1);
66     assert(commonSent1 == commonIter1);
67   }
68   {
69     auto iter1 = simple_iterator<int*>(buffer);
70     auto iter2 = comparable_iterator<int*>(buffer);
71     auto commonIter1 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(iter1);
72     auto commonSent1 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(sentinel_type<int*>{buffer + 8});
73 
74     const auto commonIter2 = std::common_iterator<decltype(iter2), sentinel_type<int*>>(iter2);
75     const auto commonSent2 = std::common_iterator<decltype(iter2), sentinel_type<int*>>(sentinel_type<int*>{buffer + 8});
76 
77     assert(commonIter1 == commonIter2);
78     assert(commonSent1 != commonIter2);
79     assert(commonSent1 == commonSent2);
80     assert(commonSent2 == commonSent1);
81 
82     assert(commonIter1 != commonSent1);
83     assert(commonIter2 != commonSent2);
84     assert(commonSent1 != commonIter1);
85     assert(commonSent2 != commonIter2);
86 
87     assert(commonIter1 == commonIter2);
88     assert(commonIter2 == commonIter1);
89 
90     for (auto i = 1; commonIter1 != commonSent1; ++i) {
91       assert(*(commonIter1++) == i);
92     }
93     assert(commonIter1 == commonSent1);
94     assert(commonSent1 == commonIter1);
95 
96     // This check may *seem* incorrect (our iterators point to two completely different
97     // elements of buffer). However, this is actually what the Standard wants.
98     // See https://eel.is/c++draft/iterators.common#common.iter.cmp-2.
99     assert(commonIter1 == commonIter2);
100   }
101   {
102     auto iter1 = cpp17_input_iterator<int*>(buffer);
103     auto commonIter1 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(iter1);
104     auto commonSent1 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(sentinel_type<int*>{buffer + 8});
105 
106     const auto commonIter2 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(iter1);
107     const auto commonSent2 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(sentinel_type<int*>{buffer + 8});
108 
109     assert(commonIter1 != commonSent1);
110     assert(commonIter2 != commonSent2);
111     assert(commonSent1 != commonIter1);
112     assert(commonSent2 != commonIter2);
113 
114     for (auto i = 1; commonIter1 != commonSent1; ++i) {
115       assert(*(commonIter1++) == i);
116     }
117     assert(commonIter1 == commonSent1);
118     assert(commonSent1 == commonIter1);
119   }
120   {
121     auto iter1 = forward_iterator<int*>(buffer);
122     auto commonIter1 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(iter1);
123     auto commonSent1 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(sentinel_type<int*>{buffer + 8});
124 
125     const auto commonIter2 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(iter1);
126     const auto commonSent2 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(sentinel_type<int*>{buffer + 8});
127 
128     assert(commonIter1 != commonSent1);
129     assert(commonIter2 != commonSent2);
130     assert(commonSent1 != commonIter1);
131     assert(commonSent2 != commonIter2);
132 
133     for (auto i = 1; commonIter1 != commonSent1; ++i) {
134       assert(*(commonIter1++) == i);
135     }
136     assert(commonIter1 == commonSent1);
137     assert(commonSent1 == commonIter1);
138   }
139   {
140     auto iter1 = random_access_iterator<int*>(buffer);
141     auto commonIter1 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(iter1);
142     auto commonSent1 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(sentinel_type<int*>{buffer + 8});
143 
144     const auto commonIter2 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(iter1);
145     const auto commonSent2 = std::common_iterator<decltype(iter1), sentinel_type<int*>>(sentinel_type<int*>{buffer + 8});
146 
147     assert(commonIter1 != commonSent1);
148     assert(commonIter2 != commonSent2);
149     assert(commonSent1 != commonIter1);
150     assert(commonSent2 != commonIter2);
151 
152     assert(commonSent1 == commonSent2);
153     assert(commonSent2 == commonSent1);
154 
155     for (auto i = 1; commonIter1 != commonSent1; ++i) {
156       assert(*(commonIter1++) == i);
157     }
158     assert(commonIter1 == commonSent1);
159     assert(commonSent1 == commonIter1);
160   }
161 }
162 
163 int main(int, char**) {
164   test();
165 
166   return 0;
167 }
168