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 V base() const& requires copy_constructible<V>;
13 // constexpr V base() &&;
14 
15 #include <ranges>
16 
17 #include <cassert>
18 #include <utility>
19 
20 #include "test_macros.h"
21 #include "types.h"
22 
23 constexpr bool hasLValueQualifiedBase(auto&& view) {
24   return requires { view.base(); };
25 }
26 
27 constexpr bool test() {
28   int buf[8] = {1, 2, 3, 4, 5, 6, 7, 8};
29 
30   {
31     CopyableView view{buf, buf + 8};
32     std::ranges::common_view<CopyableView> common(view);
33     assert(common.base().begin_ == buf);
34     assert(std::move(common).base().begin_ == buf);
35 
36     ASSERT_SAME_TYPE(decltype(common.base()), CopyableView);
37     ASSERT_SAME_TYPE(decltype(std::move(common).base()), CopyableView);
38     static_assert(hasLValueQualifiedBase(common));
39   }
40 
41   {
42     MoveOnlyView view{buf, buf + 8};
43     std::ranges::common_view<MoveOnlyView> common(std::move(view));
44     assert(std::move(common).base().begin_ == buf);
45 
46     ASSERT_SAME_TYPE(decltype(std::move(common).base()), MoveOnlyView);
47     static_assert(!hasLValueQualifiedBase(common));
48   }
49 
50   {
51     CopyableView view{buf, buf + 8};
52     const std::ranges::common_view<CopyableView> common(view);
53     assert(common.base().begin_ == buf);
54     assert(std::move(common).base().begin_ == buf);
55 
56     ASSERT_SAME_TYPE(decltype(common.base()), CopyableView);
57     ASSERT_SAME_TYPE(decltype(std::move(common).base()), CopyableView);
58     static_assert(hasLValueQualifiedBase(common));
59   }
60 
61   return true;
62 }
63 
64 int main(int, char**) {
65   test();
66   static_assert(test());
67 
68   return 0;
69 }
70