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 <cassert>
17 #include <ranges>
18 
19 #include "test_macros.h"
20 #include "types.h"
21 
22 constexpr bool hasLValueQualifiedBase(auto&& view) {
23     return requires { view.base(); };
24 }
25 
26 constexpr bool test() {
27   int buffer[4][4] = {{1111, 2222, 3333, 4444}, {555, 666, 777, 888}, {99, 1010, 1111, 1212}, {13, 14, 15, 16}};
28 
29   {
30     ChildView children[4] = {ChildView(buffer[0]), ChildView(buffer[1]), ChildView(buffer[2]), ChildView(buffer[3])};
31     auto jv = std::ranges::join_view(ParentView{children});
32     assert(std::move(jv).base().ptr_ == children);
33 
34     static_assert(!hasLValueQualifiedBase(jv));
35     ASSERT_SAME_TYPE(decltype(std::move(jv).base()), ParentView<ChildView>);
36   }
37 
38   {
39     std::ranges::join_view jv(buffer);
40     assert(jv.base().base() == buffer + 0);
41 
42     static_assert(hasLValueQualifiedBase(jv));
43     ASSERT_SAME_TYPE(decltype(jv.base()), std::ranges::ref_view<int [4][4]>);
44   }
45 
46   {
47     const std::ranges::join_view jv(buffer);
48     assert(jv.base().base() == buffer + 0);
49 
50     static_assert(hasLValueQualifiedBase(jv));
51     ASSERT_SAME_TYPE(decltype(jv.base()), std::ranges::ref_view<int [4][4]>);
52   }
53 
54   return true;
55 }
56 
57 int main(int, char**) {
58   test();
59   static_assert(test());
60 
61   return 0;
62 }
63