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 // template<class R>
14 //   reverse_view(R&&) -> reverse_view<views::all_t<R>>;
15 
16 #include <ranges>
17 #include <cassert>
18 #include <concepts>
19 
20 #include "test_iterators.h"
21 
22 struct View : std::ranges::view_base {
23   friend int* begin(View&);
24   friend int* begin(View const&);
25   friend sentinel_wrapper<int*> end(View&);
26   friend sentinel_wrapper<int*> end(View const&);
27 };
28 
29 struct Range {
30   friend int* begin(Range&);
31   friend int* begin(Range const&);
32   friend sentinel_wrapper<int*> end(Range&);
33   friend sentinel_wrapper<int*> end(Range const&);
34 };
35 
36 struct BorrowedRange {
37   friend int* begin(BorrowedRange&);
38   friend int* begin(BorrowedRange const&);
39   friend sentinel_wrapper<int*> end(BorrowedRange&);
40   friend sentinel_wrapper<int*> end(BorrowedRange const&);
41 };
42 
43 template<>
44 inline constexpr bool std::ranges::enable_borrowed_range<BorrowedRange> = true;
45 
46 void testCTAD() {
47     View v;
48     Range r;
49     BorrowedRange br;
50     static_assert(std::same_as<
51         decltype(std::ranges::reverse_view(v)),
52         std::ranges::reverse_view<View>
53     >);
54     static_assert(std::same_as<
55         decltype(std::ranges::reverse_view(r)),
56         std::ranges::reverse_view<std::ranges::ref_view<Range>>
57     >);
58     // std::ranges::reverse_view(std::move(r)) invalid. RValue range must be borrowed.
59     static_assert(std::same_as<
60         decltype(std::ranges::reverse_view(br)),
61         std::ranges::reverse_view<std::ranges::ref_view<BorrowedRange>>
62     >);
63     static_assert(std::same_as<
64         decltype(std::ranges::reverse_view(std::move(br))),
65         std::ranges::reverse_view<std::ranges::subrange<
66           int *, sentinel_wrapper<int *>, std::ranges::subrange_kind::unsized>>
67     >);
68 }
69