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 // constexpr auto operator->() const noexcept
12 //   requires contiguous_iterator<I>;
13 
14 #include <iterator>
15 
16 #include "test_macros.h"
17 #include "test_iterators.h"
18 
19 template<class Iter>
20 concept ArrowEnabled = requires(Iter& iter) {
21   iter.operator->();
22 };
23 
24 constexpr bool test() {
25   int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
26 
27   {
28     std::counted_iterator iter(contiguous_iterator<int*>{buffer}, 8);
29     for (int i = 0; i < 8; ++i, ++iter)
30       assert(iter.operator->() == buffer + i);
31 
32     static_assert(noexcept(iter.operator->()));
33   }
34   {
35     const std::counted_iterator iter(contiguous_iterator<int*>{buffer}, 8);
36     assert(iter.operator->() == buffer);
37 
38     static_assert(noexcept(iter.operator->()));
39   }
40 
41   {
42       static_assert( ArrowEnabled<std::counted_iterator<contiguous_iterator<int*>>>);
43       static_assert(!ArrowEnabled<std::counted_iterator<random_access_iterator<int*>>>);
44   }
45 
46   return true;
47 }
48 
49 int main(int, char**) {
50   test();
51   static_assert(test());
52 
53   return 0;
54 }
55