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, c++20
10
11 // constexpr iterator(iterator<!Const> i)
12 // requires Const && (convertible_to<iterator_t<Views>,
13 // iterator_t<maybe-const<Const, Views>>> && ...);
14
15 #include <ranges>
16
17 #include <cassert>
18 #include <tuple>
19
20 #include "../types.h"
21
22 using ConstIterIncompatibleView = BasicView<forward_iterator<int*>, forward_iterator<int*>,
23 random_access_iterator<const int*>, random_access_iterator<const int*>>;
24 static_assert(!std::convertible_to<std::ranges::iterator_t<ConstIterIncompatibleView>,
25 std::ranges::iterator_t<const ConstIterIncompatibleView>>);
26
test()27 constexpr bool test() {
28 int buffer[3] = {1, 2, 3};
29
30 {
31 std::ranges::zip_view v(NonSimpleCommon{buffer});
32 auto iter1 = v.begin();
33 std::ranges::iterator_t<const decltype(v)> iter2 = iter1;
34 assert(iter1 == iter2);
35
36 static_assert(!std::is_same_v<decltype(iter1), decltype(iter2)>);
37
38 // We cannot create a non-const iterator from a const iterator.
39 static_assert(!std::constructible_from<decltype(iter1), decltype(iter2)>);
40 }
41
42 {
43 // underlying non-const to const not convertible
44 std::ranges::zip_view v(ConstIterIncompatibleView{buffer});
45 auto iter1 = v.begin();
46 auto iter2 = std::as_const(v).begin();
47
48 static_assert(!std::is_same_v<decltype(iter1), decltype(iter2)>);
49
50 static_assert(!std::constructible_from<decltype(iter1), decltype(iter2)>);
51 static_assert(!std::constructible_from<decltype(iter2), decltype(iter1)>);
52 }
53
54 return true;
55 }
56
main(int,char **)57 int main(int, char**) {
58 test();
59 static_assert(test());
60
61 return 0;
62 }
63