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, c++20
10
11 // <ranges>
12
13 // constexpr auto end();
14
15 #include <ranges>
16
17 #include <cassert>
18 #include <concepts>
19 #include <functional>
20
21 #include "test_iterators.h"
22
23 struct NonCommonRange : std::ranges::view_base {
24 using Iterator = forward_iterator<int*>;
25 using Sentinel = sentinel_wrapper<Iterator>;
NonCommonRangeNonCommonRange26 constexpr explicit NonCommonRange(int* b, int* e) : begin_(b), end_(e) {}
beginNonCommonRange27 constexpr Iterator begin() const { return Iterator(begin_); }
endNonCommonRange28 constexpr Sentinel end() const { return Sentinel(Iterator(end_)); }
29
30 private:
31 int* begin_;
32 int* end_;
33 };
34
35 static_assert(std::ranges::forward_range<NonCommonRange>);
36 static_assert(!std::ranges::common_range<NonCommonRange>);
37
38 struct CommonRange : std::ranges::view_base {
39 using Iterator = bidirectional_iterator<int*>;
CommonRangeCommonRange40 constexpr explicit CommonRange(int* b, int* e) : begin_(b), end_(e) {}
beginCommonRange41 constexpr Iterator begin() const { return Iterator(begin_); }
endCommonRange42 constexpr Iterator end() const { return Iterator(end_); }
43
44 private:
45 int* begin_;
46 int* end_;
47 };
48
49 static_assert(std::ranges::bidirectional_range<CommonRange>);
50 static_assert(std::ranges::common_range<CommonRange>);
51
test()52 constexpr bool test() {
53 int buff[] = {1, 0, 3, 1, 2, 3, 4, 5};
54
55 // Check the return type of `end()`
56 {
57 CommonRange range(buff, buff + 1);
58 auto pred = [](int, int) { return true; };
59 std::ranges::chunk_by_view view(range, pred);
60 using ChunkByView = decltype(view);
61 static_assert(std::ranges::common_range<ChunkByView>);
62 ASSERT_SAME_TYPE(std::ranges::sentinel_t<ChunkByView>, decltype(view.end()));
63 }
64
65 // end() on an empty range
66 {
67 CommonRange range(buff, buff);
68 auto pred = [](int x, int y) { return x <= y; };
69 std::ranges::chunk_by_view view(range, pred);
70 auto end = view.end();
71 assert(end == std::default_sentinel);
72 }
73
74 // end() on a 1-element range
75 {
76 CommonRange range(buff, buff + 1);
77 auto pred = [](int& x, int& y) { return x <= y; };
78 std::ranges::chunk_by_view view(range, pred);
79 auto end = view.end();
80 assert(base((*--end).begin()) == buff);
81 assert(base((*end).end()) == buff + 1);
82 }
83
84 // end() on a 2-element range
85 {
86 CommonRange range(buff, buff + 2);
87 auto pred = [](int const& x, int const& y) { return x <= y; };
88 std::ranges::chunk_by_view view(range, pred);
89 auto end = view.end();
90 assert(base((*--end).begin()) == buff + 1);
91 assert(base((*--end).end()) == buff + 1);
92 }
93
94 // end() on a 8-element range
95 {
96 CommonRange range(buff, buff + 8);
97 auto pred = [](const int x, const int y) { return x < y; };
98 std::ranges::chunk_by_view view(range, pred);
99 auto end = view.end();
100 assert(base((*--end).end()) == buff + 8);
101 assert(base((*--end).end()) == buff + 3);
102 }
103
104 // end() on a non-common range
105 {
106 NonCommonRange range(buff, buff + 1);
107 std::ranges::chunk_by_view view(range, std::ranges::less_equal{});
108 auto end = view.end();
109 ASSERT_SAME_TYPE(std::default_sentinel_t, std::ranges::sentinel_t<decltype(view)>);
110 ASSERT_SAME_TYPE(std::default_sentinel_t, decltype(end));
111 }
112
113 return true;
114 }
115
main(int,char **)116 int main(int, char**) {
117 test();
118 static_assert(test());
119
120 return 0;
121 }
122