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 take_view(V base, range_difference_t<V> count); // explicit since C++23
12
13#include <cassert>
14#include <ranges>
15
16#include "test_convertible.h"
17#include "test_iterators.h"
18#include "test_macros.h"
19#include "test_range.h"
20#include "types.h"
21
22// SFINAE tests.
23
24#if TEST_STD_VER >= 23
25
26static_assert(!test_convertible<std::ranges::take_view<View>, View, std::ranges::range_difference_t<View>>(),
27 "This constructor must be explicit");
28
29#else
30
31static_assert(test_convertible<std::ranges::take_view<View>, View, std::ranges::range_difference_t<View>>(),
32 "This constructor must be explicit");
33
34#endif // TEST_STD_VER >= 23
35
36constexpr bool test() {
37 int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
38
39 {
40 std::ranges::take_view<CopyableView> tv(CopyableView{buffer}, 0);
41 assert(tv.base().ptr_ == buffer);
42 assert(tv.begin() == tv.end()); // Checking we have correct size.
43 }
44
45 {
46 std::ranges::take_view<MoveOnlyView> tv(MoveOnlyView{buffer}, 1);
47 assert(std::move(tv).base().ptr_ == buffer);
48 assert(std::ranges::next(tv.begin(), 1) == tv.end()); // Checking we have correct size.
49 }
50
51 {
52 const std::ranges::take_view<CopyableView> tv(CopyableView{buffer}, 2);
53 assert(tv.base().ptr_ == buffer);
54 assert(std::ranges::next(tv.begin(), 2) == tv.end()); // Checking we have correct size.
55 }
56
57 return true;
58}
59
60int main(int, char**) {
61 test();
62 static_assert(test());
63
64 return 0;
65}
66

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