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 end();
12
13 #include <cassert>
14 #include <ranges>
15 #include <type_traits>
16 #include <utility>
17
18 #include "test_iterators.h"
19
20 struct View : std::ranges::view_base {
21 int* begin() const;
22 int* end() const;
23 };
24
25 // Test that end is not const
26 template <class T>
27 concept HasEnd = requires(T t) { t.end(); };
28
29 struct Pred {
operator ()Pred30 constexpr bool operator()(int i) const { return i < 3; }
31 };
32
33 static_assert(HasEnd<std::ranges::drop_while_view<View, Pred>>);
34 static_assert(!HasEnd<const std::ranges::drop_while_view<View, Pred>>);
35
test()36 constexpr bool test() {
37 // return iterator
38 {
39 int buffer[] = {1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1};
40 std::ranges::drop_while_view dwv(buffer, Pred{});
41 std::same_as<int*> decltype(auto) st = dwv.end();
42 assert(st == buffer + 11);
43 }
44
45 // return sentinel
46 {
47 using Iter = int*;
48 using Sent = sentinel_wrapper<Iter>;
49 using Range = std::ranges::subrange<Iter, Sent>;
50 int buffer[] = {1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1};
51 Range range = {buffer, Sent{buffer + 11}};
52 std::ranges::drop_while_view dwv(range, Pred{});
53 std::same_as<Sent> decltype(auto) st = dwv.end();
54 assert(base(st) == buffer + 11);
55 }
56
57 return true;
58 }
59
main(int,char **)60 int main(int, char**) {
61 test();
62 static_assert(test());
63 return 0;
64 }
65