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-no-concepts
11 // UNSUPPORTED: libcpp-has-no-incomplete-ranges
12 
13 // constexpr V base() const& requires copy_constructible<V>;
14 // constexpr V base() &&;
15 
16 #include <ranges>
17 #include <cassert>
18 
19 #include "test_macros.h"
20 #include "test_iterators.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 buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
29 
30   {
31     std::ranges::take_view<CopyableView> tv(CopyableView{buffer}, 0);
32     assert(tv.base().ptr_ == buffer);
33     assert(std::move(tv).base().ptr_ == buffer);
34 
35     ASSERT_SAME_TYPE(decltype(tv.base()), CopyableView);
36     ASSERT_SAME_TYPE(decltype(std::move(tv).base()), CopyableView);
37     static_assert(hasLValueQualifiedBase(tv));
38   }
39 
40   {
41     std::ranges::take_view<MoveOnlyView> tv(MoveOnlyView{buffer}, 1);
42     assert(std::move(tv).base().ptr_ == buffer);
43 
44     ASSERT_SAME_TYPE(decltype(std::move(tv).base()), MoveOnlyView);
45     static_assert(!hasLValueQualifiedBase(tv));
46   }
47 
48   {
49     const std::ranges::take_view<CopyableView> tv(CopyableView{buffer}, 2);
50     assert(tv.base().ptr_ == buffer);
51     assert(std::move(tv).base().ptr_ == buffer);
52 
53     ASSERT_SAME_TYPE(decltype(tv.base()), CopyableView);
54     ASSERT_SAME_TYPE(decltype(std::move(tv).base()), CopyableView);
55     static_assert(hasLValueQualifiedBase(tv));
56   }
57 
58   return true;
59 }
60 
61 int main(int, char**) {
62   test();
63   static_assert(test());
64 
65   return 0;
66 }
67