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();
13 // constexpr auto begin() const requires range<const V>;
14
15 #include <ranges>
16
17 #include <cassert>
18 #include <concepts>
19 #include <utility>
20
21 #include "test_iterators.h"
22 #include "types.h"
23
24 struct MutableView : std::ranges::view_base {
25 int* begin();
26 sentinel_wrapper<int*> end();
27 };
28
29 template<class View>
30 concept BeginEnabled = requires(View v) { v.begin(); };
31
test()32 constexpr bool test() {
33 int buf[8] = {1, 2, 3, 4, 5, 6, 7, 8};
34
35 {
36 static_assert( BeginEnabled<std::ranges::common_view<CopyableView> const&>);
37 static_assert( BeginEnabled<std::ranges::common_view<MutableView>&>);
38 static_assert(!BeginEnabled<std::ranges::common_view<MutableView> const&>);
39 }
40
41 {
42 SizedRandomAccessView view{buf, buf + 8};
43 std::ranges::common_view<SizedRandomAccessView> common(view);
44 std::same_as<RandomAccessIter> auto begin = common.begin();
45 assert(begin == std::ranges::begin(view));
46 }
47
48 {
49 SizedRandomAccessView view{buf, buf + 8};
50 std::ranges::common_view<SizedRandomAccessView> const common(view);
51 std::same_as<RandomAccessIter> auto begin = common.begin();
52 assert(begin == std::ranges::begin(view));
53 }
54
55 return true;
56 }
57
main(int,char **)58 int main(int, char**) {
59 test();
60 static_assert(test());
61
62 // The non-constexpr tests:
63 int buf[8] = {1, 2, 3, 4, 5, 6, 7, 8};
64
65 {
66 SizedForwardView view{buf, buf + 8};
67 std::ranges::common_view<SizedForwardView> common(view);
68 using CommonIter = std::common_iterator<ForwardIter, sized_sentinel<ForwardIter>>;
69 std::same_as<CommonIter> auto begin = common.begin();
70 assert(begin == std::ranges::begin(view));
71 std::same_as<CommonIter> auto cbegin = std::as_const(common).begin();
72 assert(cbegin == std::ranges::begin(view));
73 }
74
75 {
76 MoveOnlyView view{buf, buf + 8};
77 std::ranges::common_view<MoveOnlyView> common(std::move(view));
78 using CommonIter = std::common_iterator<int*, sentinel_wrapper<int*>>;
79 std::same_as<CommonIter> auto begin = common.begin();
80 assert(begin == std::ranges::begin(view));
81 }
82
83 {
84 CopyableView view{buf, buf + 8};
85 std::ranges::common_view<CopyableView> const common(view);
86 using CommonIter = std::common_iterator<int*, sentinel_wrapper<int*>>;
87 std::same_as<CommonIter> auto begin = common.begin();
88 assert(begin == std::ranges::begin(view));
89 }
90
91 return 0;
92 }
93