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<forward_iterator I, sentinel_for<I> S, weakly_incrementable O>
12// requires indirectly_copyable<I, O>
13// constexpr ranges::rotate_copy_result<I, O>
14// ranges::rotate_copy(I first, I middle, S last, O result);
15// template<forward_range R, weakly_incrementable O>
16// requires indirectly_copyable<iterator_t<R>, O>
17// constexpr ranges::rotate_copy_result<borrowed_iterator_t<R>, O>
18// ranges::rotate_copy(R&& r, iterator_t<R> middle, O result);
19
20// <algorithm>
21
22#include <algorithm>
23#include <array>
24#include <cassert>
25#include <ranges>
26
27#include "almost_satisfies_types.h"
28#include "test_iterators.h"
29#include "type_algorithms.h"
30
31template <class Iter, class Out = int*, class Sent = sentinel_wrapper<Iter>>
32concept HasRotateCopyIt =
33 requires(Iter first, Sent last, Out out) { std::ranges::rotate_copy(first, first, last, out); };
34
35template <class Range, class Out = int*>
36concept HasRotateCopyR = requires(Range range, Out out) { std::ranges::rotate_copy(range, nullptr, out); };
37
38static_assert(HasRotateCopyIt<int*>);
39static_assert(!HasRotateCopyIt<ForwardIteratorNotDerivedFrom>);
40static_assert(!HasRotateCopyIt<ForwardIteratorNotIncrementable>);
41static_assert(!HasRotateCopyIt<int*, SentinelForNotSemiregular>);
42static_assert(!HasRotateCopyIt<int*, SentinelForNotWeaklyEqualityComparableWith>);
43static_assert(!HasRotateCopyIt<int*, OutputIteratorNotIndirectlyWritable>);
44static_assert(!HasRotateCopyIt<int*, OutputIteratorNotInputOrOutputIterator>);
45
46static_assert(HasRotateCopyR<UncheckedRange<int*>>);
47static_assert(!HasRotateCopyR<ForwardRangeNotDerivedFrom>);
48static_assert(!HasRotateCopyR<ForwardRangeNotIncrementable>);
49static_assert(!HasRotateCopyR<UncheckedRange<int*, SentinelForNotSemiregular>>);
50static_assert(!HasRotateCopyR<UncheckedRange<int*>, OutputIteratorNotIndirectlyWritable>);
51static_assert(!HasRotateCopyR<UncheckedRange<int*>, OutputIteratorNotInputOrOutputIterator>);
52
53static_assert(std::is_same_v<std::ranges::rotate_copy_result<int, int>, std::ranges::in_out_result<int, int>>);
54
55template <class Iter, class OutIter, class Sent, int N>
56constexpr void test(std::array<int, N> value, std::size_t middle, std::array<int, N> expected) {
57 {
58 std::array<int, N> out;
59 std::same_as<std::ranges::in_out_result<Iter, OutIter>> decltype(auto) ret = std::ranges::rotate_copy(
60 Iter(value.data()), Iter(value.data() + middle), Sent(Iter(value.data() + value.size())), OutIter(out.data()));
61 assert(base(ret.in) == value.data() + value.size());
62 assert(base(ret.out) == out.data() + out.size());
63 assert(out == expected);
64 }
65 {
66 std::array<int, N> out;
67 auto range = std::ranges::subrange(Iter(value.data()), Sent(Iter(value.data() + value.size())));
68 std::same_as<std::ranges::in_out_result<Iter, OutIter>> decltype(auto) ret =
69 std::ranges::rotate_copy(range, Iter(value.data() + middle), OutIter(out.data()));
70 assert(base(ret.in) == value.data() + value.size());
71 assert(base(ret.out) == out.data() + out.size());
72 assert(out == expected);
73 }
74}
75
76template <class Iter, class OutIter, class Sent>
77constexpr void test_iterators() {
78 // simple test
79 test<Iter, OutIter, Sent, 4>({1, 2, 3, 4}, 2, {3, 4, 1, 2});
80
81 // check that an empty range works
82 test<Iter, OutIter, Sent, 0>({}, 0, {});
83
84 // check that a single element range works
85 test<Iter, OutIter, Sent, 1>({1}, 0, {1});
86
87 // check that a two element range works
88 test<Iter, OutIter, Sent, 2>({1, 2}, 1, {2, 1});
89
90 // rotate on the first element
91 test<Iter, OutIter, Sent, 7>({1, 2, 3, 4, 5, 6, 7}, 0, {1, 2, 3, 4, 5, 6, 7});
92
93 // rotate on the second element
94 test<Iter, OutIter, Sent, 7>({1, 2, 3, 4, 5, 6, 7}, 1, {2, 3, 4, 5, 6, 7, 1});
95
96 // rotate on the last element
97 test<Iter, OutIter, Sent, 7>({1, 2, 3, 4, 5, 6, 7}, 6, {7, 1, 2, 3, 4, 5, 6});
98
99 // rotate on the one-past-the-end pointer
100 test<Iter, OutIter, Sent, 7>({1, 2, 3, 4, 5, 6, 7}, 7, {1, 2, 3, 4, 5, 6, 7});
101}
102
103constexpr bool test() {
104 types::for_each(types::forward_iterator_list<const int*>(), []<class Iter>() {
105 types::for_each(
106 types::concatenate_t<types::forward_iterator_list<int*>, types::type_list<cpp20_output_iterator<int*> > >(),
107 []<class OutIter>() { test_iterators<Iter, OutIter, Iter>(); });
108 });
109
110 {
111 struct AssignmentCounter {
112 int* counter;
113
114 constexpr AssignmentCounter(int* counter_) : counter(counter_) {}
115 constexpr AssignmentCounter& operator=(const AssignmentCounter&) {
116 ++*counter;
117 return *this;
118 }
119 };
120
121 {
122 int c = 0;
123 AssignmentCounter a[] = {&c, &c, &c, &c};
124 AssignmentCounter b[] = {&c, &c, &c, &c};
125 std::ranges::rotate_copy(a, a + 2, a + 4, b);
126 assert(c == 4);
127 }
128 {
129 int c = 0;
130 AssignmentCounter a[] = {&c, &c, &c, &c};
131 AssignmentCounter b[] = {&c, &c, &c, &c};
132 std::ranges::rotate_copy(a, a + 2, b);
133 assert(c == 4);
134 }
135 }
136
137 return true;
138}
139
140int main(int, char**) {
141 test();
142 static_assert(test());
143
144 return 0;
145}
146

source code of libcxx/test/std/algorithms/alg.modifying.operations/alg.rotate/ranges.rotate_copy.pass.cpp