| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // UNSUPPORTED: c++03, c++11, c++14, c++17 |
| |
| // constexpr V base() const & requires copy_constructible<V> { return base_; } |
| // constexpr V base() && { return std::move(base_); } |
| |
| #include <cassert> |
| #include <ranges> |
| #include <tuple> |
| #include <type_traits> |
| #include <utility> |
| |
| #include "MoveOnly.h" |
| |
| struct View : std::ranges::view_base { |
| int i; |
| std::tuple<int>* begin() const; |
| std::tuple<int>* end() const; |
| }; |
| |
| struct MoveOnlyView : View { |
| MoveOnly mo; |
| }; |
| |
| template <class T> |
| concept HasBase = requires(T&& t) { std::forward<T>(t).base(); }; |
| |
| static_assert(HasBase<std::ranges::elements_view<View, 0> const&>); |
| static_assert(HasBase<std::ranges::elements_view<View, 0>&&>); |
| |
| static_assert(!HasBase<std::ranges::elements_view<MoveOnlyView, 0> const&>); |
| static_assert(HasBase<std::ranges::elements_view<MoveOnlyView, 0>&&>); |
| |
| constexpr bool test() { |
| // const & |
| { |
| const std::ranges::elements_view<View, 0> ev{View{{}, 5}}; |
| std::same_as<View> decltype(auto) v = ev.base(); |
| assert(v.i == 5); |
| } |
| |
| // & |
| { |
| std::ranges::elements_view<View, 0> ev{View{{}, 5}}; |
| std::same_as<View> decltype(auto) v = ev.base(); |
| assert(v.i == 5); |
| } |
| |
| // && |
| { |
| std::ranges::elements_view<View, 0> ev{View{{}, 5}}; |
| std::same_as<View> decltype(auto) v = std::move(ev).base(); |
| assert(v.i == 5); |
| } |
| |
| // const && |
| { |
| const std::ranges::elements_view<View, 0> ev{View{{}, 5}}; |
| std::same_as<View> decltype(auto) v = std::move(ev).base(); |
| assert(v.i == 5); |
| } |
| |
| // move only |
| { |
| std::ranges::elements_view<MoveOnlyView, 0> ev{MoveOnlyView{{}, 5}}; |
| std::same_as<MoveOnlyView> decltype(auto) v = std::move(ev).base(); |
| assert(v.mo.get() == 5); |
| } |
| |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| static_assert(test()); |
| return 0; |
| } |