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-has-no-incomplete-ranges
11 
12 // constexpr auto size() requires sized_range<V>;
13 // constexpr auto size() const requires sized_range<const V>;
14 
15 #include <ranges>
16 
17 #include <cassert>
18 #include <utility>
19 
20 #include "test_macros.h"
21 #include "types.h"
22 
23 // end -  begin = 8, but size may return something else.
24 template<CopyCategory CC>
25 struct BidirSizedRange : std::ranges::view_base {
26   int *ptr_;
27   size_t size_;
28 
29   constexpr BidirSizedRange(int *ptr, size_t size) : ptr_(ptr), size_(size) {}
30   constexpr BidirSizedRange(const BidirSizedRange &) requires (CC == Copyable) = default;
31   constexpr BidirSizedRange(BidirSizedRange &&) requires (CC == MoveOnly) = default;
32   constexpr BidirSizedRange& operator=(const BidirSizedRange &) requires (CC == Copyable) = default;
33   constexpr BidirSizedRange& operator=(BidirSizedRange &&) requires (CC == MoveOnly) = default;
34 
35   constexpr bidirectional_iterator<int*> begin() { return bidirectional_iterator<int*>{ptr_}; }
36   constexpr bidirectional_iterator<const int*> begin() const { return bidirectional_iterator<const int*>{ptr_}; }
37   constexpr bidirectional_iterator<int*> end() { return bidirectional_iterator<int*>{ptr_ + 8}; }
38   constexpr bidirectional_iterator<const int*> end() const { return bidirectional_iterator<const int*>{ptr_ + 8}; }
39 
40   constexpr size_t size() const { return size_; }
41 };
42 
43 constexpr bool test() {
44   int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
45 
46   // Non-common, non-const bidirectional range.
47   {
48     auto rev = std::ranges::reverse_view(BidirSizedRange<Copyable>{buffer, 4});
49     assert(std::ranges::size(rev) == 4);
50     assert(rev.size() == 4);
51     assert(std::move(rev).size() == 4);
52 
53     ASSERT_SAME_TYPE(decltype(rev.size()), size_t);
54     ASSERT_SAME_TYPE(decltype(std::move(rev).size()), size_t);
55   }
56   // Non-common, const bidirectional range.
57   {
58     const auto rev = std::ranges::reverse_view(BidirSizedRange<Copyable>{buffer, 4});
59     assert(std::ranges::size(rev) == 4);
60     assert(rev.size() == 4);
61     assert(std::move(rev).size() == 4);
62 
63     ASSERT_SAME_TYPE(decltype(rev.size()), size_t);
64     ASSERT_SAME_TYPE(decltype(std::move(rev).size()), size_t);
65   }
66   // Non-common, non-const (move only) bidirectional range.
67   {
68     auto rev = std::ranges::reverse_view(BidirSizedRange<MoveOnly>{buffer, 4});
69     assert(std::move(rev).size() == 4);
70 
71     ASSERT_SAME_TYPE(decltype(std::move(rev).size()), size_t);
72   }
73 
74   return true;
75 }
76 
77 int main(int, char**) {
78   test();
79   static_assert(test());
80 
81   return 0;
82 }
83