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 // UNSUPPORTED: libcpp-has-no-incomplete-ranges
12 
13 // constexpr auto size() requires sized_range<V>;
14 // constexpr auto size() const requires sized_range<const V>;
15 
16 #include <ranges>
17 
18 #include <cassert>
19 #include <utility>
20 
21 #include "test_macros.h"
22 #include "types.h"
23 
24 // end -  begin = 8, but size may return something else.
25 template<CopyCategory CC>
26 struct BidirSizedRange : std::ranges::view_base {
27   int *ptr_;
28   size_t size_;
29 
30   constexpr BidirSizedRange(int *ptr, size_t size) : ptr_(ptr), size_(size) {}
31   constexpr BidirSizedRange(const BidirSizedRange &) requires (CC == Copyable) = default;
32   constexpr BidirSizedRange(BidirSizedRange &&) requires (CC == MoveOnly) = default;
33   constexpr BidirSizedRange& operator=(const BidirSizedRange &) requires (CC == Copyable) = default;
34   constexpr BidirSizedRange& operator=(BidirSizedRange &&) requires (CC == MoveOnly) = default;
35 
36   constexpr bidirectional_iterator<int*> begin() { return bidirectional_iterator<int*>{ptr_}; }
37   constexpr bidirectional_iterator<const int*> begin() const { return bidirectional_iterator<const int*>{ptr_}; }
38   constexpr bidirectional_iterator<int*> end() { return bidirectional_iterator<int*>{ptr_ + 8}; }
39   constexpr bidirectional_iterator<const int*> end() const { return bidirectional_iterator<const int*>{ptr_ + 8}; }
40 
41   constexpr size_t size() const { return size_; }
42 };
43 
44 constexpr bool test() {
45   int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
46 
47   // Non-common, non-const bidirectional range.
48   {
49     auto rev = std::ranges::reverse_view(BidirSizedRange<Copyable>{buffer, 4});
50     assert(std::ranges::size(rev) == 4);
51     assert(rev.size() == 4);
52     assert(std::move(rev).size() == 4);
53 
54     ASSERT_SAME_TYPE(decltype(rev.size()), size_t);
55     ASSERT_SAME_TYPE(decltype(std::move(rev).size()), size_t);
56   }
57   // Non-common, const bidirectional range.
58   {
59     const auto rev = std::ranges::reverse_view(BidirSizedRange<Copyable>{buffer, 4});
60     assert(std::ranges::size(rev) == 4);
61     assert(rev.size() == 4);
62     assert(std::move(rev).size() == 4);
63 
64     ASSERT_SAME_TYPE(decltype(rev.size()), size_t);
65     ASSERT_SAME_TYPE(decltype(std::move(rev).size()), size_t);
66   }
67   // Non-common, non-const (move only) bidirectional range.
68   {
69     auto rev = std::ranges::reverse_view(BidirSizedRange<MoveOnly>{buffer, 4});
70     assert(std::move(rev).size() == 4);
71 
72     ASSERT_SAME_TYPE(decltype(std::move(rev).size()), size_t);
73   }
74 
75   return true;
76 }
77 
78 int main(int, char**) {
79   test();
80   static_assert(test());
81 
82   return 0;
83 }
84