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// std::views::single
12
13#include <ranges>
14
15#include <cassert>
16#include <concepts>
17#include <utility>
18#include "MoveOnly.h"
19
20// Can't invoke without arguments.
21static_assert(!std::is_invocable_v<decltype((std::views::single))>);
22#if _LIBCPP_STD_VER >= 23
23// Can invoke with a move-only type.
24static_assert(std::is_invocable_v<decltype((std::views::single)), MoveOnly>);
25#endif
26constexpr bool test() {
27 // Lvalue.
28 {
29 int x = 42;
30 std::same_as<std::ranges::single_view<int>> decltype(auto) v = std::views::single(x);
31 assert(v.size() == 1);
32 assert(v.front() == x);
33 }
34
35 // Prvalue.
36 {
37 std::same_as<std::ranges::single_view<int>> decltype(auto) v = std::views::single(42);
38 assert(v.size() == 1);
39 assert(v.front() == 42);
40 }
41
42 // Const lvalue.
43 {
44 const int x = 42;
45 std::same_as<std::ranges::single_view<int>> decltype(auto) v = std::views::single(x);
46 assert(v.size() == 1);
47 assert(v.front() == x);
48 }
49
50 // Xvalue.
51 {
52 int x = 42;
53 std::same_as<std::ranges::single_view<int>> decltype(auto) v = std::views::single(std::move(x));
54 assert(v.size() == 1);
55 assert(v.front() == x);
56 }
57
58 return true;
59}
60
61int main(int, char**) {
62 test();
63 static_assert(test());
64
65 return 0;
66}
67

source code of libcxx/test/std/ranges/range.factories/range.single.view/cpo.pass.cpp