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   int *begin() const;
23   sentinel_wrapper<int*> end() const;
24 };
25 
26 struct Range {
27   int *begin() const;
28   sentinel_wrapper<int*> end() const;
29 };
30 
31 struct BorrowedRange {
32   int *begin() const;
33   sentinel_wrapper<int*> end() const;
34 };
35 template<>
36 inline constexpr bool std::ranges::enable_borrowed_range<BorrowedRange> = true;
37 
38 void testCTAD() {
39     View v;
40     Range r;
41     BorrowedRange br;
42     static_assert(std::same_as<
43         decltype(std::ranges::common_view(v)),
44         std::ranges::common_view<View>
45     >);
46     static_assert(std::same_as<
47         decltype(std::ranges::common_view(r)),
48         std::ranges::common_view<std::ranges::ref_view<Range>>
49     >);
50     // std::ranges::common_view(std::move(r)) invalid. RValue range must be borrowed.
51     static_assert(std::same_as<
52         decltype(std::ranges::common_view(br)),
53         std::ranges::common_view<std::ranges::ref_view<BorrowedRange>>
54     >);
55     static_assert(std::same_as<
56         decltype(std::ranges::common_view(std::move(br))),
57         std::ranges::common_view<std::ranges::subrange<
58           int *, sentinel_wrapper<int *>, std::ranges::subrange_kind::unsized>>
59     >);
60 }
61