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-no-concepts
11 
12 // constexpr auto operator->() const noexcept
13 //   requires contiguous_iterator<I>;
14 
15 #include <iterator>
16 
17 #include "test_macros.h"
18 #include "test_iterators.h"
19 
20 template<class Iter>
21 concept ArrowEnabled = requires(Iter& iter) {
22   iter.operator->();
23 };
24 
25 constexpr bool test() {
26   int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
27 
28   {
29     std::counted_iterator iter(contiguous_iterator<int*>{buffer}, 8);
30     for (int i = 0; i < 8; ++i, ++iter)
31       assert(iter.operator->() == buffer + i);
32 
33     static_assert(noexcept(iter.operator->()));
34   }
35   {
36     const std::counted_iterator iter(contiguous_iterator<int*>{buffer}, 8);
37     assert(iter.operator->() == buffer);
38 
39     static_assert(noexcept(iter.operator->()));
40   }
41 
42   {
43       static_assert( ArrowEnabled<std::counted_iterator<contiguous_iterator<int*>>>);
44       static_assert(!ArrowEnabled<std::counted_iterator<random_access_iterator<int*>>>);
45   }
46 
47   return true;
48 }
49 
50 int main(int, char**) {
51   test();
52   static_assert(test());
53 
54   return 0;
55 }
56