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, c++20
10
11 // std::views::as_rvalue
12
13 #include <cassert>
14 #include <functional>
15 #include <ranges>
16 #include <vector>
17
18 #include "test_iterators.h"
19
20 struct DefaultConstructibleView : std::ranges::view_base {
21 int i_;
22 int* begin();
23 int* end();
24 };
25
26 struct RValueView : std::ranges::view_base {};
27
28 template <class View, class T>
29 concept HasPipe = requires(View&& view, T&& t) {
30 { std::forward<View>(view) | std::forward<T>(t) };
31 };
32
33 struct NoView {};
34 static_assert(std::is_invocable_v<decltype(std::views::as_rvalue), DefaultConstructibleView>);
35 static_assert(!std::is_invocable_v<decltype(std::views::as_rvalue)>);
36 static_assert(!std::is_invocable_v<decltype(std::views::as_rvalue), NoView>);
37 static_assert(HasPipe<DefaultConstructibleView&, decltype(std::views::as_rvalue)>);
38 static_assert(HasPipe<int (&)[10], decltype(std::views::as_rvalue)>);
39 static_assert(!HasPipe<int (&&)[10], decltype(std::views::as_rvalue)>);
40 static_assert(!HasPipe<NoView, decltype(std::views::as_rvalue)>);
41 static_assert(std::is_same_v<decltype(std::views::as_rvalue), decltype(std::ranges::views::as_rvalue)>);
42
43 struct move_iterator_range {
beginmove_iterator_range44 constexpr std::move_iterator<int*> begin() const { return {}; }
endmove_iterator_range45 constexpr std::move_iterator<int*> end() const { return {}; }
46 };
47
48 static_assert(!std::ranges::view<move_iterator_range>);
49 static_assert(std::ranges::range<move_iterator_range>);
50
test()51 constexpr bool test() {
52 { // view | views::as_rvalue
53 DefaultConstructibleView v{{}, 3};
54 std::same_as<std::ranges::as_rvalue_view<DefaultConstructibleView>> decltype(auto) view = v | std::views::as_rvalue;
55 assert(view.base().i_ == 3);
56 }
57
58 { // adaptor | views::as_rvalue
59 DefaultConstructibleView v{{}, 3};
60 const auto partial = std::views::transform(std::identity{}) | std::views::as_rvalue;
61 std::same_as<std::ranges::as_rvalue_view<
62 std::ranges::transform_view<DefaultConstructibleView, std::identity>>> decltype(auto) view = partial(v);
63 assert(view.base().base().i_ == 3);
64 }
65
66 { // views::as_rvalue | adaptor
67 DefaultConstructibleView v{{}, 3};
68 const auto partial = std::views::as_rvalue | std::views::transform(std::identity{});
69 std::same_as<std::ranges::transform_view<std::ranges::as_rvalue_view<DefaultConstructibleView>,
70 std::identity>> decltype(auto) view = partial(v);
71 assert(view.base().base().i_ == 3);
72 }
73
74 { // rvalue-view | views::as_rvalue
75 int a[4] = {1, 2, 3, 4};
76 std::ranges::subrange range(rvalue_iterator{a}, rvalue_iterator{a + 4});
77 [[maybe_unused]] std::same_as<std::ranges::subrange<rvalue_iterator<int>>> decltype(auto) rval_range =
78 range | std::views::as_rvalue;
79 }
80
81 { // range | views::as_rvalue
82 [[maybe_unused]] std::same_as<std::ranges::as_rvalue_view<std::views::all_t<std::vector<int>>>> decltype(auto)
83 view = std::vector<int>{} | std::views::as_rvalue;
84 }
85
86 { // rvalue-range | views::as_rvalue
87 [[maybe_unused]] std::same_as<std::views::all_t<move_iterator_range>> decltype(auto) view =
88 move_iterator_range{} | std::views::as_rvalue;
89 }
90
91 return true;
92 }
93
main(int,char **)94 int main(int, char**) {
95 test();
96 static_assert(test());
97
98 return 0;
99 }
100