xref: /llvm-project/libcxx/test/std/iterators/predef.iterators/counted.iterator/compare.pass.cpp (revision d2baefae6846765eef6a6dd69d4fdf1082ce29ad)
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 // template<common_with<I> I2>
13 //   friend constexpr bool operator==(
14 //     const counted_iterator& x, const counted_iterator<I2>& y);
15 // friend constexpr bool operator==(
16 //   const counted_iterator& x, default_sentinel_t);
17 
18 #include <iterator>
19 
20 #include "test_macros.h"
21 #include "test_iterators.h"
22 
23 // This iterator is common_with forward_iterator but NOT comparable with it.
24 template <class It>
25 class CommonWithForwardIter
26 {
27     It it_;
28 
29 public:
30     typedef          std::input_iterator_tag                   iterator_category;
31     typedef typename std::iterator_traits<It>::value_type      value_type;
32     typedef typename std::iterator_traits<It>::difference_type difference_type;
33     typedef It                                                 pointer;
34     typedef typename std::iterator_traits<It>::reference       reference;
35 
36     constexpr It base() const {return it_;}
37 
38     CommonWithForwardIter() = default;
39     explicit constexpr CommonWithForwardIter(It it) : it_(it) {}
40     constexpr CommonWithForwardIter(const forward_iterator<It>& it) : it_(it.base()) {}
41 
42     constexpr reference operator*() const {return *it_;}
43 
44     constexpr CommonWithForwardIter& operator++() {++it_; return *this;}
45     constexpr CommonWithForwardIter operator++(int)
46         {CommonWithForwardIter tmp(*this); ++(*this); return tmp;}
47 };
48 
49 struct InputOrOutputArchetype {
50   using difference_type = int;
51 
52   int *ptr;
53 
54   constexpr int operator*() { return *ptr; }
55   constexpr void operator++(int) { ++ptr; }
56   constexpr InputOrOutputArchetype& operator++() { ++ptr; return *this; }
57 };
58 
59 constexpr bool test() {
60   int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
61 
62   {
63     {
64       std::counted_iterator iter1(forward_iterator<int*>(buffer), 8);
65       std::counted_iterator iter2(CommonWithForwardIter<int*>(buffer), 8);
66 
67       assert(iter1 == iter2);
68       assert(iter2 == iter1);
69       ++iter1;
70       assert(iter1 != iter2);
71       assert(iter2 != iter1);
72     }
73   }
74 
75   {
76     {
77       std::counted_iterator iter(cpp20_input_iterator<int*>(buffer), 8);
78 
79       assert(iter != std::default_sentinel);
80       assert(std::default_sentinel == std::ranges::next(std::move(iter), 8));
81     }
82     {
83       std::counted_iterator iter(forward_iterator<int*>(buffer), 8);
84 
85       assert(iter != std::default_sentinel);
86       assert(std::default_sentinel == std::ranges::next(iter, 8));
87     }
88     {
89       std::counted_iterator iter(random_access_iterator<int*>(buffer), 8);
90 
91       assert(iter != std::default_sentinel);
92       assert(std::default_sentinel == std::ranges::next(iter, 8));
93     }
94     {
95       std::counted_iterator iter(InputOrOutputArchetype{buffer}, 8);
96 
97       assert(iter != std::default_sentinel);
98       assert(std::default_sentinel == std::ranges::next(iter, 8));
99     }
100   }
101 
102 
103   return true;
104 }
105 
106 int main(int, char**) {
107   test();
108   static_assert(test());
109 
110   return 0;
111 }
112