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<sized_sentinel_for<I> I2, sized_sentinel_for<I> S2>
13 //   requires sized_sentinel_for<S, I2>
14 // friend iter_difference_t<I2> operator-(
15 //   const common_iterator& x, const common_iterator<I2, S2>& y);
16 
17 #include <iterator>
18 #include <cassert>
19 
20 #include "test_macros.h"
21 #include "types.h"
22 
23 void test() {
24   int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
25 
26   {
27     auto iter1 = random_access_iterator<int*>(buffer);
28     auto commonIter1 = std::common_iterator<decltype(iter1), sized_sentinel_type<int*>>(iter1);
29     auto commonSent1 = std::common_iterator<decltype(iter1), sized_sentinel_type<int*>>(sized_sentinel_type<int*>{buffer + 8});
30     assert(commonIter1 - commonSent1 == -8);
31     assert(commonSent1 - commonIter1 == 8);
32     assert(commonIter1 - commonIter1 == 0);
33     assert(commonSent1 - commonSent1 == 0);
34   }
35   {
36     auto iter1 = simple_iterator<int*>(buffer);
37     auto iter2 = comparable_iterator<int*>(buffer);
38     auto commonIter1 = std::common_iterator<decltype(iter1), sized_sentinel_type<int*>>(iter1);
39     auto commonIter2 = std::common_iterator<decltype(iter2), sized_sentinel_type<int*>>(iter2);
40 
41     assert(commonIter1 - commonIter2 == 0);
42   }
43   {
44     auto iter1 = random_access_iterator<int*>(buffer);
45     const auto commonIter1 = std::common_iterator<decltype(iter1), sized_sentinel_type<int*>>(iter1);
46     const auto commonSent1 = std::common_iterator<decltype(iter1), sized_sentinel_type<int*>>(sized_sentinel_type<int*>{buffer + 8});
47     assert(commonIter1 - commonSent1 == -8);
48     assert(commonSent1 - commonIter1 == 8);
49     assert(commonIter1 - commonIter1 == 0);
50     assert(commonSent1 - commonSent1 == 0);
51   }
52   {
53     auto iter1 = simple_iterator<int*>(buffer);
54     auto iter2 = comparable_iterator<int*>(buffer);
55     const auto commonIter1 = std::common_iterator<decltype(iter1), sized_sentinel_type<int*>>(iter1);
56     const auto commonIter2 = std::common_iterator<decltype(iter2), sized_sentinel_type<int*>>(iter2);
57 
58     assert(commonIter1 - commonIter2 == 0);
59   }
60 }
61 
62 int main(int, char**) {
63   test();
64 
65   return 0;
66 }
67