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-no-concepts 11 // UNSUPPORTED: libcpp-has-no-incomplete-ranges 12 13 // reverse_view() requires default_initializable<V> = default; 14 15 #include <ranges> 16 #include <cassert> 17 18 #include "types.h" 19 20 enum CtorKind { DefaultCtor, PtrCtor }; 21 template<CtorKind CK> 22 struct BidirRangeWith : std::ranges::view_base { 23 int *ptr_ = nullptr; 24 25 constexpr BidirRangeWith() requires (CK == DefaultCtor) = default; 26 constexpr BidirRangeWith(int *ptr); 27 28 constexpr bidirectional_iterator<int*> begin() { return bidirectional_iterator<int*>{ptr_}; } 29 constexpr bidirectional_iterator<const int*> begin() const { return bidirectional_iterator<const int*>{ptr_}; } 30 constexpr bidirectional_iterator<int*> end() { return bidirectional_iterator<int*>{ptr_ + 8}; } 31 constexpr bidirectional_iterator<const int*> end() const { return bidirectional_iterator<const int*>{ptr_ + 8}; } 32 }; 33 34 constexpr bool test() { 35 { 36 static_assert( std::default_initializable<std::ranges::reverse_view<BidirRangeWith<DefaultCtor>>>); 37 static_assert(!std::default_initializable<std::ranges::reverse_view<BidirRangeWith<PtrCtor>>>); 38 } 39 40 { 41 std::ranges::reverse_view<BidirRangeWith<DefaultCtor>> rev; 42 assert(rev.base().ptr_ == nullptr); 43 } 44 { 45 const std::ranges::reverse_view<BidirRangeWith<DefaultCtor>> rev; 46 assert(rev.base().ptr_ == nullptr); 47 } 48 49 return true; 50 } 51 52 int main(int, char**) { 53 test(); 54 static_assert(test()); 55 56 return 0; 57 } 58 59