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 #include <cassert>
17 
18 #include "test_macros.h"
19 #include "test_iterators.h"
20 #include "test_range.h"
21 #include "types.h"
22 
23 template<class T>
24 concept SizeEnabled = requires(const std::ranges::take_view<T>& tv) {
25   tv.size();
26 };
27 
28 constexpr bool test() {
29   int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
30 
31   {
32     static_assert( SizeEnabled<SizedRandomAccessView>);
33     static_assert(!SizeEnabled<CopyableView>);
34   }
35 
36   {
37     std::ranges::take_view<SizedRandomAccessView> tv(SizedRandomAccessView{buffer}, 0);
38     assert(tv.size() == 0);
39   }
40 
41   {
42     const std::ranges::take_view<SizedRandomAccessView> tv(SizedRandomAccessView{buffer}, 2);
43     assert(tv.size() == 2);
44   }
45 
46   {
47     std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 4);
48     assert(tv.size() == 4);
49   }
50 
51   {
52     const std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 6);
53     assert(tv.size() == 6);
54   }
55 
56   {
57     std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 8);
58     assert(tv.size() == 8);
59   }
60   {
61     const std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 8);
62     assert(tv.size() == 8);
63   }
64 
65   {
66     std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 10);
67     assert(tv.size() == 8);
68   }
69   {
70     const std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 10);
71     assert(tv.size() == 8);
72   }
73 
74   return true;
75 }
76 
77 int main(int, char**) {
78   test();
79   static_assert(test());
80 
81   return 0;
82 }
83