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 "test_iterators.h"
21 #include "test_range.h"
22 #include "types.h"
23 
24 template<class T>
25 concept SizeEnabled = requires(const std::ranges::take_view<T>& tv) {
26   tv.size();
27 };
28 
29 constexpr bool test() {
30   int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
31 
32   {
33     static_assert( SizeEnabled<SizedRandomAccessView>);
34     static_assert(!SizeEnabled<CopyableView>);
35   }
36 
37   {
38     std::ranges::take_view<SizedRandomAccessView> tv(SizedRandomAccessView{buffer}, 0);
39     assert(tv.size() == 0);
40   }
41 
42   {
43     const std::ranges::take_view<SizedRandomAccessView> tv(SizedRandomAccessView{buffer}, 2);
44     assert(tv.size() == 2);
45   }
46 
47   {
48     std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 4);
49     assert(tv.size() == 4);
50   }
51 
52   {
53     const std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 6);
54     assert(tv.size() == 6);
55   }
56 
57   {
58     std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 8);
59     assert(tv.size() == 8);
60   }
61   {
62     const std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 8);
63     assert(tv.size() == 8);
64   }
65 
66   {
67     std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 10);
68     assert(tv.size() == 8);
69   }
70   {
71     const std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 10);
72     assert(tv.size() == 8);
73   }
74 
75   return true;
76 }
77 
78 int main(int, char**) {
79   test();
80   static_assert(test());
81 
82   return 0;
83 }
84