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 #include <cassert>
18 
19 #include "test_macros.h"
20 #include "types.h"
21 
22 // end -  begin = 8, but size may return something else.
23 template<CopyCategory CC>
24 struct BidirSizedRange : std::ranges::view_base {
25   int *ptr_;
26   size_t size_;
27 
28   constexpr BidirSizedRange(int *ptr, size_t size) : ptr_(ptr), size_(size) {}
29   constexpr BidirSizedRange(const BidirSizedRange &) requires (CC == Copyable) = default;
30   constexpr BidirSizedRange(BidirSizedRange &&) requires (CC == MoveOnly) = default;
31   constexpr BidirSizedRange& operator=(const BidirSizedRange &) requires (CC == Copyable) = default;
32   constexpr BidirSizedRange& operator=(BidirSizedRange &&) requires (CC == MoveOnly) = default;
33 
34   constexpr bidirectional_iterator<int*> begin() { return bidirectional_iterator<int*>{ptr_}; }
35   constexpr bidirectional_iterator<const int*> begin() const { return bidirectional_iterator<const int*>{ptr_}; }
36   constexpr bidirectional_iterator<int*> end() { return bidirectional_iterator<int*>{ptr_ + 8}; }
37   constexpr bidirectional_iterator<const int*> end() const { return bidirectional_iterator<const int*>{ptr_ + 8}; }
38 
39   constexpr size_t size() const { return size_; }
40 };
41 
42 constexpr bool test() {
43   int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
44 
45   // Non-common, non-const bidirectional range.
46   {
47     auto rev = std::ranges::reverse_view(BidirSizedRange<Copyable>{buffer, 4});
48     assert(std::ranges::size(rev) == 4);
49     assert(rev.size() == 4);
50     assert(std::move(rev).size() == 4);
51 
52     ASSERT_SAME_TYPE(decltype(rev.size()), size_t);
53     ASSERT_SAME_TYPE(decltype(std::move(rev).size()), size_t);
54   }
55   // Non-common, const bidirectional range.
56   {
57     const auto rev = std::ranges::reverse_view(BidirSizedRange<Copyable>{buffer, 4});
58     assert(std::ranges::size(rev) == 4);
59     assert(rev.size() == 4);
60     assert(std::move(rev).size() == 4);
61 
62     ASSERT_SAME_TYPE(decltype(rev.size()), size_t);
63     ASSERT_SAME_TYPE(decltype(std::move(rev).size()), size_t);
64   }
65   // Non-common, non-const (move only) bidirectional range.
66   {
67     auto rev = std::ranges::reverse_view(BidirSizedRange<MoveOnly>{buffer, 4});
68     assert(std::move(rev).size() == 4);
69 
70     ASSERT_SAME_TYPE(decltype(std::move(rev).size()), size_t);
71   }
72 
73   return true;
74 }
75 
76 int main(int, char**) {
77   test();
78   static_assert(test());
79 
80   return 0;
81 }
82