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 // constexpr auto begin() requires (!simple-view<V>);
13 // constexpr auto begin() const requires range<const V>;
14
15 #include <ranges>
16 #include <cassert>
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 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
test()31 constexpr bool test() {
32 int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
33
34 // sized_range && random_access_iterator
35 {
36 std::ranges::take_view<SizedRandomAccessView> tv(SizedRandomAccessView(buffer), 4);
37 assert(tv.begin() == SizedRandomAccessView(buffer).begin());
38 ASSERT_SAME_TYPE(decltype(tv.begin()), RandomAccessIter);
39 }
40
41 {
42 const std::ranges::take_view<SizedRandomAccessView> tv(SizedRandomAccessView(buffer), 4);
43 assert(tv.begin() == SizedRandomAccessView(buffer).begin());
44 ASSERT_SAME_TYPE(decltype(tv.begin()), RandomAccessIter);
45 }
46
47 // sized_range && !random_access_iterator
48 {
49 std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 4);
50 assert(tv.begin() == std::counted_iterator<ForwardIter>(ForwardIter(buffer), 4));
51 ASSERT_SAME_TYPE(decltype(tv.begin()), std::counted_iterator<ForwardIter>);
52 }
53
54 {
55 const std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 4);
56 assert(tv.begin() == std::counted_iterator<ForwardIter>(ForwardIter(buffer), 4));
57 ASSERT_SAME_TYPE(decltype(tv.begin()), std::counted_iterator<ForwardIter>);
58 }
59
60 // !sized_range
61 {
62 std::ranges::take_view<MoveOnlyView> tv(MoveOnlyView{buffer}, 4);
63 assert(tv.begin() == std::counted_iterator<int*>(buffer, 4));
64 ASSERT_SAME_TYPE(decltype(tv.begin()), std::counted_iterator<int*>);
65 }
66
67 {
68 const std::ranges::take_view<MoveOnlyView> tv(MoveOnlyView{buffer}, 4);
69 assert(tv.begin() == std::counted_iterator<int*>(buffer, 4));
70 ASSERT_SAME_TYPE(decltype(tv.begin()), std::counted_iterator<int*>);
71 }
72
73 // __simple_view<V> && sized_range<V> && !size_range<!V>
74 {
75 std::ranges::take_view<NonCommonSimpleView> tv{};
76 ASSERT_SAME_TYPE(decltype(tv.begin()), std::counted_iterator<int*>);
77 ASSERT_SAME_TYPE(decltype(std::as_const(tv).begin()), std::counted_iterator<int*>);
78 }
79
80 return true;
81 }
82
main(int,char **)83 int main(int, char**) {
84 test();
85 static_assert(test());
86
87 return 0;
88 }
89