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 decltype(auto) operator*() const;
13 
14 #include <cassert>
15 #include <ranges>
16 
17 #include "test_macros.h"
18 #include "../types.h"
19 
20 constexpr bool test() {
21   int buffer[4][4] = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}, {13, 14, 15, 16}};
22 
23   {
24     std::ranges::join_view jv(buffer);
25     auto iter = jv.begin();
26     for (int i = 1; i < 17; ++i) {
27       assert(*iter++ == i);
28     }
29   }
30   {
31     std::ranges::join_view jv(buffer);
32     auto iter = std::next(jv.begin(), 15);
33     assert(*iter++ == 16);
34     assert(iter == jv.end());
35   }
36   {
37     ChildView children[4] = {ChildView(buffer[0]), ChildView(buffer[1]), ChildView(buffer[2]), ChildView(buffer[3])};
38     auto jv = std::ranges::join_view(ParentView(children));
39     auto iter = jv.begin();
40     for (int i = 1; i < 17; ++i) {
41       assert(*iter == i);
42       ++iter;
43     }
44   }
45 
46   return true;
47 }
48 
49 int main(int, char**) {
50   test();
51   static_assert(test());
52 
53   return 0;
54 }
55