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 decltype(auto) inner-iterator::operator*() const;
12 
13 #include <ranges>
14 
15 #include "../types.h"
16 
test()17 constexpr bool test() {
18   // Can call `inner-iterator::operator*`; `View` is a forward range.
19   {
20     SplitViewDiff v("abc def", " ");
21     auto val = *v.begin();
22 
23     // Non-const iterator.
24     {
25       auto i = val.begin();
26       static_assert(std::same_as<decltype(*i), char&>);
27       assert(*i == 'a');
28       assert(*(++i) == 'b');
29       assert(*(++i) == 'c');
30     }
31 
32     // Const iterator.
33     {
34       const auto ci = val.begin();
35       static_assert(std::same_as<decltype(*ci), char&>);
36       assert(*ci == 'a');
37     }
38   }
39 
40   // Can call `inner-iterator::operator*`; `View` is an input range.
41   {
42     SplitViewInput v("abc def", ' ');
43     auto val = *v.begin();
44 
45     // Non-const iterator.
46     {
47       auto i = val.begin();
48       static_assert(std::same_as<decltype(*i), char&>);
49       assert(*i == 'a');
50       assert(*(++i) == 'b');
51       assert(*(++i) == 'c');
52     }
53 
54     // Const iterator.
55     {
56       const auto ci = val.begin();
57       static_assert(std::same_as<decltype(*ci), char&>);
58       // Note: when the underlying range is an input range, `current` is stored in the `lazy_split_view` itself and
59       // shared between `inner-iterator`s. Consequently, incrementing one iterator effectively increments all of them.
60       assert(*ci == 'c');
61     }
62   }
63 
64   return true;
65 }
66 
main(int,char **)67 int main(int, char**) {
68   test();
69   static_assert(test());
70 
71   return 0;
72 }
73