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 // constexpr auto begin() requires (!simple-view<V>);
12 // constexpr auto begin() const requires range<const V>;
13
14 #include <cassert>
15 #include <ranges>
16 #include <utility>
17
18 #include "test_macros.h"
19 #include "test_iterators.h"
20 #include "test_range.h"
21 #include "types.h"
22
23 struct NonCommonSimpleView : std::ranges::view_base {
24 int* begin() const;
25 sentinel_wrapper<int*> end() const;
sizeNonCommonSimpleView26 std::size_t size() { return 0; } // deliberately non-const
27 };
28 static_assert(std::ranges::sized_range<NonCommonSimpleView>);
29 static_assert(!std::ranges::sized_range<const NonCommonSimpleView>);
30
31 using CommonInputIterPtrConstInt = common_input_iterator<const int*>;
32 using CountedCommonInputIterPtrConstInt = std::counted_iterator<CommonInputIterPtrConstInt>;
33
test()34 constexpr bool test() {
35 int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
36
37 // simple-view<V> && sized_range<V> && random_access_range<V>
38 {
39 using ViewTested = SizedRandomAccessView;
40 static_assert(simple_view<ViewTested>);
41 static_assert(std::ranges::sized_range<ViewTested>);
42 static_assert(std::ranges::random_access_range<ViewTested>);
43
44 std::ranges::take_view<ViewTested> tv(ViewTested(buffer), 4);
45 assert(tv.begin() == ViewTested(buffer).begin());
46 ASSERT_SAME_TYPE(decltype(tv.begin()), RandomAccessIter);
47
48 const std::ranges::take_view<ViewTested> ctv(ViewTested(buffer), 4);
49 assert(ctv.begin() == ViewTested(buffer).begin());
50 ASSERT_SAME_TYPE(decltype(ctv.begin()), RandomAccessIter);
51 }
52
53 // simple-view<V> && sized_range<V> && !random_access_range<V>
54 {
55 using ViewTested = SizedForwardView;
56 static_assert(simple_view<ViewTested>);
57 static_assert(std::ranges::sized_range<ViewTested>);
58 static_assert(!std::ranges::random_access_range<ViewTested>);
59
60 std::ranges::take_view<ViewTested> tv(ViewTested{buffer}, 16); // underlying size is 8
61 assert(tv.begin() == std::counted_iterator<ForwardIter>(ForwardIter(buffer), 8)); // expect min(8, 16)
62 ASSERT_SAME_TYPE(decltype(tv.begin()), std::counted_iterator<ForwardIter>);
63
64 const std::ranges::take_view<ViewTested> ctv(ViewTested{buffer}, 4);
65 assert(ctv.begin() == std::counted_iterator<ForwardIter>(ForwardIter(buffer), 4));
66 ASSERT_SAME_TYPE(decltype(ctv.begin()), std::counted_iterator<ForwardIter>);
67 }
68
69 // simple-view<V> && !sized_range<V>
70 {
71 using ViewTested = MoveOnlyView;
72 static_assert(simple_view<ViewTested>);
73 std::ranges::take_view<ViewTested> tv(ViewTested{buffer}, 4);
74 assert(tv.begin() == std::counted_iterator<int*>(buffer, 4));
75 ASSERT_SAME_TYPE(decltype(tv.begin()), std::counted_iterator<int*>);
76
77 const std::ranges::take_view<ViewTested> ctv(ViewTested{buffer}, 4);
78 assert(ctv.begin() == std::counted_iterator<int*>(buffer, 4));
79 ASSERT_SAME_TYPE(decltype(ctv.begin()), std::counted_iterator<int*>);
80 }
81
82 // simple-view<V> && sized_range<V> && !sized_range<const V>
83 {
84 using ViewTested = NonCommonSimpleView;
85 static_assert(simple_view<ViewTested>);
86 static_assert(std::ranges::sized_range<ViewTested>);
87 static_assert(!std::ranges::sized_range<const ViewTested>);
88
89 std::ranges::take_view<ViewTested> tv{};
90 ASSERT_SAME_TYPE(decltype(tv.begin()), std::counted_iterator<int*>);
91 ASSERT_SAME_TYPE(decltype(std::as_const(tv).begin()), std::counted_iterator<int*>);
92 }
93
94 // !simple-view<V> && !sized_range<V>
95 {
96 using ViewTested = NonSimpleNonSizedView;
97 static_assert(!simple_view<ViewTested>);
98 static_assert(!std::ranges::sized_range<ViewTested>);
99
100 std::ranges::take_view<ViewTested> tv{ViewTested{buffer, buffer + 2}, 4};
101 // The count for the counted iterator is the count of the take_view (i.e., 4)
102 assert(tv.begin() == CountedCommonInputIterPtrConstInt(CommonInputIterPtrConstInt(buffer), 4));
103 ASSERT_SAME_TYPE(decltype(tv.begin()), CountedCommonInputIterPtrConstInt);
104 }
105
106 // !simple-view<V> && sized_range<V>
107 {
108 using ViewTested = NonSimpleSizedView;
109 static_assert(!simple_view<ViewTested>);
110 static_assert(std::ranges::sized_range<ViewTested>);
111
112 std::ranges::take_view<ViewTested> tv{ViewTested{buffer, buffer + 2}, 4};
113 // The count for the counted iterator is the min(2, 4) (i.e., 2).
114 assert(tv.begin() == CountedCommonInputIterPtrConstInt(CommonInputIterPtrConstInt(buffer), 2));
115 ASSERT_SAME_TYPE(decltype(tv.begin()), CountedCommonInputIterPtrConstInt);
116 }
117
118 // !simple-view<V> && sized_range<V> && random_access_range<V>
119 {
120 using ViewTested = NonSimpleSizedRandomView;
121 static_assert(!simple_view<ViewTested>);
122 static_assert(std::ranges::sized_range<ViewTested>);
123 static_assert(std::ranges::random_access_range<ViewTested>);
124
125 std::ranges::take_view<ViewTested> tv{ViewTested{buffer, buffer + 2}, 4};
126 assert(tv.begin() == random_access_iterator<const int*>(buffer));
127 ASSERT_SAME_TYPE(decltype(tv.begin()), random_access_iterator<const int*>);
128 }
129 return true;
130 }
131
main(int,char **)132 int main(int, char**) {
133 test();
134 static_assert(test());
135
136 return 0;
137 }
138