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-has-no-incomplete-ranges
11
12 // template<class R>
13 // drop_view(R&&, range_difference_t<R>) -> drop_view<views::all_t<R>>;
14
15 #include <cassert>
16 #include <concepts>
17 #include <ranges>
18 #include <utility>
19
20 struct View : std::ranges::view_base {
21 int *begin() const;
22 int *end() const;
23 };
24
25 struct Range {
26 int *begin() const;
27 int *end() const;
28 };
29
30 struct BorrowedRange {
31 int *begin() const;
32 int *end() const;
33 };
34 template<>
35 inline constexpr bool std::ranges::enable_borrowed_range<BorrowedRange> = true;
36
testCTAD()37 void testCTAD() {
38 View v;
39 Range r;
40 BorrowedRange br;
41
42 static_assert(std::same_as<
43 decltype(std::ranges::drop_view(v, 0)),
44 std::ranges::drop_view<View>
45 >);
46 static_assert(std::same_as<
47 decltype(std::ranges::drop_view(std::move(v), 0)),
48 std::ranges::drop_view<View>
49 >);
50 static_assert(std::same_as<
51 decltype(std::ranges::drop_view(r, 0)),
52 std::ranges::drop_view<std::ranges::ref_view<Range>>
53 >);
54 static_assert(std::same_as<
55 decltype(std::ranges::drop_view(std::move(r), 0)),
56 std::ranges::drop_view<std::ranges::owning_view<Range>>
57 >);
58 static_assert(std::same_as<
59 decltype(std::ranges::drop_view(br, 0)),
60 std::ranges::drop_view<std::ranges::ref_view<BorrowedRange>>
61 >);
62 static_assert(std::same_as<
63 decltype(std::ranges::drop_view(std::move(br), 0)),
64 std::ranges::drop_view<std::ranges::owning_view<BorrowedRange>>
65 >);
66 }
67