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// ranges::next(it, n)
12
13#include <iterator>
14
15#include <cassert>
16#include <concepts>
17#include <utility>
18
19#include "test_iterators.h"
20
21template <typename It>
22constexpr void check(int* first, std::iter_difference_t<It> n, int* expected) {
23 It it(first);
24 std::same_as<It> auto result = std::ranges::next(std::move(it), n);
25 assert(base(result) == expected);
26}
27
28constexpr bool test() {
29 int range[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
30
31 // Check next() forward
32 for (int n = 0; n != 10; ++n) {
33 check<cpp17_input_iterator<int*>>( range, n, range+n);
34 check<cpp20_input_iterator<int*>>( range, n, range+n);
35 check<forward_iterator<int*>>( range, n, range+n);
36 check<bidirectional_iterator<int*>>(range, n, range+n);
37 check<random_access_iterator<int*>>(range, n, range+n);
38 check<contiguous_iterator<int*>>( range, n, range+n);
39 check<int*>( range, n, range+n);
40 check<cpp17_output_iterator<int*> >(range, n, range+n);
41 }
42
43 // Check next() backward
44 for (int n = 0; n != 10; ++n) {
45 check<bidirectional_iterator<int*>>(range+9, -n, range+9 - n);
46 check<random_access_iterator<int*>>(range+9, -n, range+9 - n);
47 check<contiguous_iterator<int*>>( range+9, -n, range+9 - n);
48 check<int*>( range+9, -n, range+9 - n);
49 }
50
51 return true;
52}
53
54int main(int, char**) {
55 test();
56 static_assert(test());
57 return 0;
58}
59

source code of libcxx/test/std/iterators/iterator.primitives/range.iter.ops/range.iter.ops.next/iterator_count.pass.cpp