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 // template<borrowed_range R>
13 // requires convertible-to-non-slicing<iterator_t<R>, I> &&
14 // convertible_to<sentinel_t<R>, S>
15 // constexpr subrange(R&& r, make-unsigned-like-t<iter_difference_t<I>> n)
16 // requires (K == subrange_kind::sized);
17
18 #include <ranges>
19 #include <cassert>
20
21 struct BorrowedRange {
BorrowedRangeBorrowedRange22 constexpr explicit BorrowedRange(int* b, int* e) : begin_(b), end_(e) { }
beginBorrowedRange23 constexpr int* begin() const { return begin_; }
endBorrowedRange24 constexpr int* end() const { return end_; }
25
26 private:
27 int* begin_;
28 int* end_;
29 };
30
31 namespace std::ranges {
32 template <>
33 inline constexpr bool enable_borrowed_range<::BorrowedRange> = true;
34 }
35
test()36 constexpr bool test() {
37 int buff[] = {1, 2, 3, 4, 5, 6, 7, 8};
38 using Subrange = std::ranges::subrange<int*, int*, std::ranges::subrange_kind::sized>;
39
40 // Test with an empty range
41 {
42 BorrowedRange range(buff, buff);
43 Subrange subrange(range, 0);
44 assert(subrange.size() == 0);
45 }
46
47 // Test with non-empty ranges
48 {
49 BorrowedRange range(buff, buff + 1);
50 Subrange subrange(range, 1);
51 assert(subrange.size() == 1);
52 }
53 {
54 BorrowedRange range(buff, buff + 2);
55 Subrange subrange(range, 2);
56 assert(subrange[0] == 1);
57 assert(subrange[1] == 2);
58 assert(subrange.size() == 2);
59 }
60 {
61 BorrowedRange range(buff, buff + 8);
62 Subrange subrange(range, 8);
63 assert(subrange[0] == 1);
64 assert(subrange[1] == 2);
65 // ...
66 assert(subrange[7] == 8);
67 assert(subrange.size() == 8);
68 }
69
70 return true;
71 }
72
main(int,char **)73 int main(int, char**) {
74 test();
75 static_assert(test());
76
77 return 0;
78 }
79