| //===----------------------------------------------------------------------===// |
| // |
| // 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 <type_traits> |
| #include <utility> |
| |
| #include "MoveOnly.h" |
| |
| struct View : std::ranges::view_base { |
| int i; |
| int* begin() const; |
| 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::split_view<View, View> const&>); |
| static_assert(HasBase<std::ranges::split_view<View, View>&&>); |
| |
| static_assert(!HasBase<std::ranges::split_view<MoveOnlyView, View> const&>); |
| static_assert(HasBase<std::ranges::split_view<MoveOnlyView, View>&&>); |
| |
| constexpr bool test() { |
| // const & |
| { |
| const std::ranges::split_view<View, View> sv{View{{}, 5}, View{{}, 0}}; |
| std::same_as<View> decltype(auto) v = sv.base(); |
| assert(v.i == 5); |
| } |
| |
| // & |
| { |
| std::ranges::split_view<View, View> sv{View{{}, 5}, View{{}, 0}}; |
| std::same_as<View> decltype(auto) v = sv.base(); |
| assert(v.i == 5); |
| } |
| |
| // && |
| { |
| std::ranges::split_view<View, View> sv{View{{}, 5}, View{{}, 0}}; |
| std::same_as<View> decltype(auto) v = std::move(sv).base(); |
| assert(v.i == 5); |
| } |
| |
| // const && |
| { |
| std::ranges::split_view<View, View> sv{View{{}, 5}, View{{}, 0}}; |
| std::same_as<View> decltype(auto) v = std::move(sv).base(); |
| assert(v.i == 5); |
| } |
| |
| // move only |
| { |
| std::ranges::split_view<MoveOnlyView, View> sv{MoveOnlyView{{}, 5}, View{{}, 0}}; |
| std::same_as<MoveOnlyView> decltype(auto) v = std::move(sv).base(); |
| assert(v.mo.get() == 5); |
| } |
| |
| // LWG 3590 split_view::base() const & is overconstrained |
| { |
| struct CopyCtorButNotAssignable : std::ranges::view_base { |
| int i; |
| constexpr CopyCtorButNotAssignable(int ii) : i(ii) {} |
| constexpr CopyCtorButNotAssignable(const CopyCtorButNotAssignable&) = default; |
| constexpr CopyCtorButNotAssignable(CopyCtorButNotAssignable&&) = default; |
| constexpr CopyCtorButNotAssignable& operator=(CopyCtorButNotAssignable&&) = default; |
| constexpr CopyCtorButNotAssignable& operator=(const CopyCtorButNotAssignable&) = delete; |
| constexpr int* begin() const { return nullptr; } |
| constexpr int* end() const { return nullptr; } |
| }; |
| static_assert(std::copy_constructible<CopyCtorButNotAssignable>); |
| static_assert(!std::copyable<CopyCtorButNotAssignable>); |
| const std::ranges::split_view<CopyCtorButNotAssignable, CopyCtorButNotAssignable> sv{ |
| CopyCtorButNotAssignable{5}, CopyCtorButNotAssignable{5}}; |
| std::same_as<CopyCtorButNotAssignable> decltype(auto) v = sv.base(); |
| assert(v.i == 5); |
| } |
| |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| static_assert(test()); |
| return 0; |
| } |