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