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 // friend constexpr void iter_swap(const iterator& x, const iterator& y);
13
14 #include <cassert>
15 #include <ranges>
16
17 #include "../types.h"
18
19 using NonSwappableView = BufferView<copying_iterator<int*>>;
20 static_assert(std::ranges::input_range<NonSwappableView>);
21 static_assert(!std::indirectly_swappable<std::ranges::iterator_t<NonSwappableView>>);
22
test()23 constexpr bool test() {
24 int buffer[4][4] = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}, {13, 14, 15, 16}};
25
26 {
27 std::ranges::join_view jv(buffer);
28 auto iter1 = jv.begin();
29 auto iter2 = std::next(jv.begin());
30 assert(buffer[0][0] == 1);
31 assert(buffer[0][1] == 2);
32 std::ranges::iter_swap(iter1, iter2);
33 assert(buffer[0][0] == 2);
34 assert(buffer[0][1] == 1);
35
36 static_assert(noexcept(std::ranges::iter_swap(iter1, iter2)));
37 }
38
39 {
40 // iter_move calls inner's iter_swap
41 IterMoveSwapAwareView inners[1] = {buffer[0]};
42 std::ranges::join_view jv(inners);
43 auto it1 = jv.begin();
44 auto it2 = std::ranges::next(it1);
45
46 const auto& iter_swap_called_times = jv.base().begin()->iter_swap_called;
47
48 assert(iter_swap_called_times == 0);
49 assert(buffer[0][0] == 2);
50 assert(buffer[0][1] == 1);
51
52 std::ranges::iter_swap(it1, it2);
53
54 assert(buffer[0][0] == 1);
55 assert(buffer[0][1] == 2);
56 assert(iter_swap_called_times == 1);
57 }
58
59 {
60 // LWG3517 `join_view::iterator`'s `iter_swap` is underconstrained
61 // `iter_swap` should not be defined if Inner's iterator does not indirectly_swappable
62 NonSwappableView inners[2] = {buffer[0], buffer[1]};
63 std::ranges::join_view jv(inners);
64 using Iter = std::ranges::iterator_t<decltype(jv)>;
65 static_assert(!std::indirectly_swappable<Iter>);
66 }
67 return true;
68 }
69
main(int,char **)70 int main(int, char**) {
71 test();
72 static_assert(test());
73
74 return 0;
75 }
76