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
11// template<borrowed_range R>
12// requires convertible-to-non-slicing<iterator_t<R>, I> &&
13// convertible_to<sentinel_t<R>, S>
14// constexpr subrange(R&& r, make-unsigned-like-t<iter_difference_t<I>> n)
15// requires (K == subrange_kind::sized);
16
17#include <ranges>
18#include <cassert>
19
20struct BorrowedRange {
21 constexpr explicit BorrowedRange(int* b, int* e) : begin_(b), end_(e) { }
22 constexpr int* begin() const { return begin_; }
23 constexpr int* end() const { return end_; }
24
25private:
26 int* begin_;
27 int* end_;
28};
29
30template <>
31inline constexpr bool std::ranges::enable_borrowed_range<BorrowedRange> = true;
32
33constexpr bool test() {
34 int buff[] = {1, 2, 3, 4, 5, 6, 7, 8};
35 using Subrange = std::ranges::subrange<int*, int*, std::ranges::subrange_kind::sized>;
36
37 // Test with an empty range
38 {
39 BorrowedRange range(buff, buff);
40 Subrange subrange(range, 0);
41 assert(subrange.size() == 0);
42 }
43
44 // Test with non-empty ranges
45 {
46 BorrowedRange range(buff, buff + 1);
47 Subrange subrange(range, 1);
48 assert(subrange.size() == 1);
49 }
50 {
51 BorrowedRange range(buff, buff + 2);
52 Subrange subrange(range, 2);
53 assert(subrange[0] == 1);
54 assert(subrange[1] == 2);
55 assert(subrange.size() == 2);
56 }
57 {
58 BorrowedRange range(buff, buff + 8);
59 Subrange subrange(range, 8);
60 assert(subrange[0] == 1);
61 assert(subrange[1] == 2);
62 // ...
63 assert(subrange[7] == 8);
64 assert(subrange.size() == 8);
65 }
66
67 return true;
68}
69
70int main(int, char**) {
71 test();
72 static_assert(test());
73
74 return 0;
75}
76

source code of libcxx/test/std/ranges/range.utility/range.subrange/ctor.range_size.pass.cpp