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 
12 // template<class T>
13 // concept borrowed_range;
14 
15 #include <ranges>
16 
17 struct NotRange {
18   int begin() const;
19   int end() const;
20 };
21 
22 struct Range {
23   int *begin();
24   int *end();
25 };
26 
27 struct ConstRange {
28   int *begin() const;
29   int *end() const;
30 };
31 
32 struct BorrowedRange {
33   int *begin() const;
34   int *end() const;
35 };
36 
37 template<>
38 inline constexpr bool std::ranges::enable_borrowed_range<BorrowedRange> = true;
39 
40 static_assert(!std::ranges::borrowed_range<NotRange>);
41 static_assert(!std::ranges::borrowed_range<NotRange&>);
42 static_assert(!std::ranges::borrowed_range<const NotRange>);
43 static_assert(!std::ranges::borrowed_range<const NotRange&>);
44 static_assert(!std::ranges::borrowed_range<NotRange&&>);
45 
46 static_assert(!std::ranges::borrowed_range<Range>);
47 static_assert( std::ranges::borrowed_range<Range&>);
48 static_assert(!std::ranges::borrowed_range<const Range>);
49 static_assert(!std::ranges::borrowed_range<const Range&>);
50 static_assert(!std::ranges::borrowed_range<Range&&>);
51 
52 static_assert(!std::ranges::borrowed_range<ConstRange>);
53 static_assert( std::ranges::borrowed_range<ConstRange&>);
54 static_assert(!std::ranges::borrowed_range<const ConstRange>);
55 static_assert( std::ranges::borrowed_range<const ConstRange&>);
56 static_assert(!std::ranges::borrowed_range<ConstRange&&>);
57 
58 static_assert( std::ranges::borrowed_range<BorrowedRange>);
59 static_assert( std::ranges::borrowed_range<BorrowedRange&>);
60 static_assert( std::ranges::borrowed_range<const BorrowedRange>);
61 static_assert( std::ranges::borrowed_range<const BorrowedRange&>);
62 static_assert( std::ranges::borrowed_range<BorrowedRange&&>);
63