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 // constexpr sentinel(sentinel<!Const> s);
12
13 #include <cassert>
14 #include <ranges>
15
16 #include "../types.h"
17
18 template <class T>
19 struct convertible_sentinel_wrapper {
20 explicit convertible_sentinel_wrapper() = default;
convertible_sentinel_wrapperconvertible_sentinel_wrapper21 constexpr convertible_sentinel_wrapper(const T& it) : it_(it) {}
22
23 template <class U>
24 requires std::convertible_to<const U&, T>
convertible_sentinel_wrapperconvertible_sentinel_wrapper25 constexpr convertible_sentinel_wrapper(const convertible_sentinel_wrapper<U>& other) : it_(other.it_) {}
26
operator ==(convertible_sentinel_wrapper const & self,const T & other)27 constexpr friend bool operator==(convertible_sentinel_wrapper const& self, const T& other) {
28 return self.it_ == other;
29 }
30 T it_;
31 };
32
33 struct NonSimpleNonCommonConvertibleView : IntBufferView {
34 using IntBufferView::IntBufferView;
35
beginNonSimpleNonCommonConvertibleView36 constexpr int* begin() { return buffer_; }
beginNonSimpleNonCommonConvertibleView37 constexpr const int* begin() const { return buffer_; }
endNonSimpleNonCommonConvertibleView38 constexpr convertible_sentinel_wrapper<int*> end() { return convertible_sentinel_wrapper<int*>(buffer_ + size_); }
endNonSimpleNonCommonConvertibleView39 constexpr convertible_sentinel_wrapper<const int*> end() const {
40 return convertible_sentinel_wrapper<const int*>(buffer_ + size_);
41 }
42 };
43
44 static_assert(!std::ranges::common_range<NonSimpleNonCommonConvertibleView>);
45 static_assert(std::ranges::random_access_range<NonSimpleNonCommonConvertibleView>);
46 static_assert(!std::ranges::sized_range<NonSimpleNonCommonConvertibleView>);
47 static_assert(std::convertible_to<std::ranges::sentinel_t<NonSimpleNonCommonConvertibleView>,
48 std::ranges::sentinel_t<NonSimpleNonCommonConvertibleView const>>);
49 static_assert(!simple_view<NonSimpleNonCommonConvertibleView>);
50
test()51 constexpr bool test() {
52 int buffer1[4] = {1, 2, 3, 4};
53 int buffer2[5] = {1, 2, 3, 4, 5};
54 std::ranges::zip_view v{NonSimpleNonCommonConvertibleView(buffer1), NonSimpleNonCommonConvertibleView(buffer2)};
55 static_assert(!std::ranges::common_range<decltype(v)>);
56 auto sent1 = v.end();
57 std::ranges::sentinel_t<const decltype(v)> sent2 = sent1;
58 static_assert(!std::is_same_v<decltype(sent1), decltype(sent2)>);
59
60 assert(v.begin() != sent2);
61 assert(std::as_const(v).begin() != sent2);
62 assert(v.begin() + 4 == sent2);
63 assert(std::as_const(v).begin() + 4 == sent2);
64
65 // Cannot create a non-const iterator from a const iterator.
66 static_assert(!std::constructible_from<decltype(sent1), decltype(sent2)>);
67 return true;
68 }
69
main(int,char **)70 int main(int, char**) {
71 test();
72 static_assert(test());
73
74 return 0;
75 }
76