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
11// constexpr auto size() requires sized_range<V>
12// constexpr auto size() const requires sized_range<const V>
13
14#include <ranges>
15#include <cassert>
16
17#include "test_macros.h"
18#include "test_iterators.h"
19#include "test_range.h"
20#include "types.h"
21
22template<class T>
23concept SizeEnabled = requires(const std::ranges::take_view<T>& tv) {
24 tv.size();
25};
26
27constexpr bool test() {
28 int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
29
30 {
31 static_assert( SizeEnabled<SizedRandomAccessView>);
32 static_assert(!SizeEnabled<CopyableView>);
33 }
34
35 {
36 std::ranges::take_view<SizedRandomAccessView> tv(SizedRandomAccessView{buffer}, 0);
37 assert(tv.size() == 0);
38 }
39
40 {
41 const std::ranges::take_view<SizedRandomAccessView> tv(SizedRandomAccessView{buffer}, 2);
42 assert(tv.size() == 2);
43 }
44
45 {
46 std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 4);
47 assert(tv.size() == 4);
48 }
49
50 {
51 const std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 6);
52 assert(tv.size() == 6);
53 }
54
55 {
56 std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 8);
57 assert(tv.size() == 8);
58 }
59 {
60 const std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 8);
61 assert(tv.size() == 8);
62 }
63
64 {
65 std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 10);
66 assert(tv.size() == 8);
67 }
68 {
69 const std::ranges::take_view<SizedForwardView> tv(SizedForwardView{buffer}, 10);
70 assert(tv.size() == 8);
71 }
72
73 return true;
74}
75
76int main(int, char**) {
77 test();
78 static_assert(test());
79
80 return 0;
81}
82

source code of libcxx/test/std/ranges/range.adaptors/range.take/size.pass.cpp