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//===----------------------------------------------------------------------===//
//
// 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;
}
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