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: gcc-10
12 // UNSUPPORTED: libcpp-has-no-incomplete-ranges
13 
14 // constexpr V base() const& requires copy_constructible<V>;
15 // constexpr V base() &&;
16 
17 #include <ranges>
18 #include <cassert>
19 
20 #include "test_macros.h"
21 #include "test_iterators.h"
22 #include "types.h"
23 
24 constexpr bool hasLValueQualifiedBase(auto&& view) {
25     return requires { view.base(); };
26 }
27 
28 constexpr bool test() {
29   int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
30 
31   {
32     std::ranges::take_view<CopyableView> tv(CopyableView{buffer}, 0);
33     assert(tv.base().ptr_ == buffer);
34     assert(std::move(tv).base().ptr_ == buffer);
35 
36     ASSERT_SAME_TYPE(decltype(tv.base()), CopyableView);
37     ASSERT_SAME_TYPE(decltype(std::move(tv).base()), CopyableView);
38     static_assert(hasLValueQualifiedBase(tv));
39   }
40 
41   {
42     std::ranges::take_view<ContiguousView> tv(ContiguousView{buffer}, 1);
43     assert(std::move(tv).base().ptr_ == buffer);
44 
45     ASSERT_SAME_TYPE(decltype(std::move(tv).base()), ContiguousView);
46     static_assert(!hasLValueQualifiedBase(tv));
47   }
48 
49   {
50     const std::ranges::take_view<CopyableView> tv(CopyableView{buffer}, 2);
51     assert(tv.base().ptr_ == buffer);
52     assert(std::move(tv).base().ptr_ == buffer);
53 
54     ASSERT_SAME_TYPE(decltype(tv.base()), CopyableView);
55     ASSERT_SAME_TYPE(decltype(std::move(tv).base()), CopyableView);
56     static_assert(hasLValueQualifiedBase(tv));
57   }
58 
59   return true;
60 }
61 
62 int main(int, char**) {
63   test();
64   static_assert(test());
65 
66   return 0;
67 }
68