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