| 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 | // reverse_view() requires default_initializable<V> = default; |
| 12 | |
| 13 | #include <ranges> |
| 14 | #include <cassert> |
| 15 | |
| 16 | #include "types.h" |
| 17 | |
| 18 | enum CtorKind { DefaultCtor, PtrCtor }; |
| 19 | template<CtorKind CK> |
| 20 | struct BidirRangeWith : std::ranges::view_base { |
| 21 | int *ptr_ = nullptr; |
| 22 | |
| 23 | constexpr BidirRangeWith() requires (CK == DefaultCtor) = default; |
| 24 | constexpr BidirRangeWith(int *ptr); |
| 25 | |
| 26 | constexpr bidirectional_iterator<int*> begin() { return bidirectional_iterator<int*>{ptr_}; } |
| 27 | constexpr bidirectional_iterator<const int*> begin() const { return bidirectional_iterator<const int*>{ptr_}; } |
| 28 | constexpr bidirectional_iterator<int*> end() { return bidirectional_iterator<int*>{ptr_ + 8}; } |
| 29 | constexpr bidirectional_iterator<const int*> end() const { return bidirectional_iterator<const int*>{ptr_ + 8}; } |
| 30 | }; |
| 31 | |
| 32 | constexpr bool test() { |
| 33 | { |
| 34 | static_assert( std::default_initializable<std::ranges::reverse_view<BidirRangeWith<DefaultCtor>>>); |
| 35 | static_assert(!std::default_initializable<std::ranges::reverse_view<BidirRangeWith<PtrCtor>>>); |
| 36 | } |
| 37 | |
| 38 | { |
| 39 | std::ranges::reverse_view<BidirRangeWith<DefaultCtor>> rev; |
| 40 | assert(rev.base().ptr_ == nullptr); |
| 41 | } |
| 42 | { |
| 43 | const std::ranges::reverse_view<BidirRangeWith<DefaultCtor>> rev; |
| 44 | assert(rev.base().ptr_ == nullptr); |
| 45 | } |
| 46 | |
| 47 | return true; |
| 48 | } |
| 49 | |
| 50 | int main(int, char**) { |
| 51 | test(); |
| 52 | static_assert(test()); |
| 53 | |
| 54 | return 0; |
| 55 | } |
| 56 | |
| 57 | |