25 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// template<class T>12// inline constexpr bool enable_borrowed_range<common_view<T>> = enable_borrowed_range<T>;13 14#include <ranges>15 16// common_view can only wrap Ts that are `view<T> && !common_range<T>`, so we need to invent one.17struct Uncommon : std::ranges::view_base {18 int *begin() const;19 std::unreachable_sentinel_t end() const;20};21 22static_assert(!std::ranges::borrowed_range<std::ranges::common_view<Uncommon>>);23static_assert(!std::ranges::borrowed_range<std::ranges::common_view<std::ranges::owning_view<Uncommon>>>);24static_assert( std::ranges::borrowed_range<std::ranges::common_view<std::ranges::ref_view<Uncommon>>>);25