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 // ranges::advance(it, sent)
12 
13 #include <iterator>
14 
15 #include <algorithm>
16 #include <cassert>
17 #include <cstddef>
18 
19 #include "../types.h"
20 #include "test_iterators.h"
21 #include "test_macros.h"
22 
23 template <bool Count, class It>
24 constexpr void check_assignable(int* first, int* last, int* expected) {
25   {
26     It it(first);
27     auto sent = assignable_sentinel(It(last));
28     std::ranges::advance(it, sent);
29     ASSERT_SAME_TYPE(decltype(std::ranges::advance(it, sent)), void);
30     assert(base(it) == expected);
31   }
32 
33   // Count operations
34   if constexpr (Count) {
35     IteratorOpCounts ops;
36     auto it   = operation_counting_iterator(It(first), &ops);
37     auto sent = assignable_sentinel(operation_counting_iterator(It(last), &ops));
38     std::ranges::advance(it, sent);
39     assert(base(base(it)) == expected);
40     assert(ops.increments + ops.decrements == 0); // because we got here by assigning from last, not by incrementing
41   }
42 }
43 
44 template <bool Count, class It>
45 constexpr void check_sized_sentinel(int* first, int* last, int* expected) {
46   auto size = (last - first);
47 
48   {
49     It it(first);
50     auto sent = distance_apriori_sentinel(size);
51     std::ranges::advance(it, sent);
52     ASSERT_SAME_TYPE(decltype(std::ranges::advance(it, sent)), void);
53     assert(base(it) == expected);
54   }
55 
56   // Count operations
57   if constexpr (Count) {
58     IteratorOpCounts ops;
59     auto it   = operation_counting_iterator(It(first), &ops);
60     auto sent = distance_apriori_sentinel(size);
61     std::ranges::advance(it, sent);
62     if constexpr (std::random_access_iterator<It>) {
63       assert(ops.increments + ops.decrements + ops.zero_moves == 1);
64     } else {
65       const auto big   = std::max(ops.increments, ops.decrements);
66       const auto small = std::min(ops.increments, ops.decrements);
67       assert(big == static_cast<size_t>(size > 0 ? size : -size));
68       assert(small == 0);
69     }
70   }
71 }
72 
73 template <bool Count, class It>
74 constexpr void check_sentinel(int* first, int* last, int* expected) {
75   auto size = (last - first);
76 
77   {
78     It it(first);
79     auto sent = sentinel_wrapper(It(last));
80     std::ranges::advance(it, sent);
81     ASSERT_SAME_TYPE(decltype(std::ranges::advance(it, sent)), void);
82     assert(base(it) == expected);
83   }
84 
85   // Count operations
86   if constexpr (Count) {
87     IteratorOpCounts ops;
88     auto it   = operation_counting_iterator(It(first), &ops);
89     auto sent = sentinel_wrapper(operation_counting_iterator(It(last), &ops));
90     std::ranges::advance(it, sent);
91     const auto big   = std::max(ops.increments, ops.decrements);
92     const auto small = std::min(ops.increments, ops.decrements);
93     assert(big == static_cast<size_t>(size > 0 ? size : -size));
94     assert(small == 0);
95   }
96 }
97 
98 constexpr bool test() {
99   int range[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
100 
101   for (int n = 0; n != 10; ++n) {
102     check_assignable<false, cpp17_input_iterator<int*>>(  range, range+n, range+n);
103     check_assignable<false, cpp20_input_iterator<int*>>(  range, range+n, range+n);
104     check_assignable<true,  forward_iterator<int*>>(      range, range+n, range+n);
105     check_assignable<true,  bidirectional_iterator<int*>>(range, range+n, range+n);
106     check_assignable<true,  random_access_iterator<int*>>(range, range+n, range+n);
107     check_assignable<true,  contiguous_iterator<int*>>(   range, range+n, range+n);
108     check_assignable<true,  int*>(                        range, range+n, range+n);
109 
110     check_sized_sentinel<false, cpp17_input_iterator<int*>>(  range, range+n, range+n);
111     check_sized_sentinel<false, cpp20_input_iterator<int*>>(  range, range+n, range+n);
112     check_sized_sentinel<true,  forward_iterator<int*>>(      range, range+n, range+n);
113     check_sized_sentinel<true,  bidirectional_iterator<int*>>(range, range+n, range+n);
114     check_sized_sentinel<true,  random_access_iterator<int*>>(range, range+n, range+n);
115     check_sized_sentinel<true,  contiguous_iterator<int*>>(   range, range+n, range+n);
116     check_sized_sentinel<true,  int*>(                        range, range+n, range+n);
117 
118     check_sentinel<false, cpp17_input_iterator<int*>>(  range, range+n, range+n);
119     check_sentinel<false, cpp20_input_iterator<int*>>(  range, range+n, range+n);
120     check_sentinel<true,  forward_iterator<int*>>(      range, range+n, range+n);
121     check_sentinel<true,  bidirectional_iterator<int*>>(range, range+n, range+n);
122     check_sentinel<true,  random_access_iterator<int*>>(range, range+n, range+n);
123     check_sentinel<true,  contiguous_iterator<int*>>(   range, range+n, range+n);
124     check_sentinel<true,  int*>(                        range, range+n, range+n);
125   }
126 
127   return true;
128 }
129 
130 int main(int, char**) {
131   assert(test());
132   static_assert(test());
133   return 0;
134 }
135