57 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++11, c++14, c++1710 11// reverse_view() requires default_initializable<V> = default;12 13#include <ranges>14#include <cassert>15 16#include "types.h"17 18enum CtorKind { DefaultCtor, PtrCtor };19template<CtorKind CK>20struct 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 32constexpr 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 50int main(int, char**) {51 test();52 static_assert(test());53 54 return 0;55}56 57