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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 auto size() requires sized_range<V>
// constexpr auto size() const requires sized_range<const V>
#include <cassert>
#include <ranges>
#include <tuple>
#include <utility>
#include "types.h"
template <class T>
concept HasSize = requires(T t) { t.size(); };
static_assert(HasSize<std::ranges::elements_view<SimpleCommon, 0>>);
static_assert(HasSize<const std::ranges::elements_view<SimpleCommon, 0>>);
struct NonSized : std::ranges::view_base {
using iterator = forward_iterator<std::tuple<int>*>;
iterator begin() const;
iterator end() const;
};
static_assert(!std::ranges::sized_range<NonSized>);
static_assert(!std::ranges::sized_range<const NonSized>);
static_assert(!HasSize<std::ranges::elements_view<NonSized, 0>>);
static_assert(!HasSize<const std::ranges::elements_view<NonSized, 0>>);
struct SizedNonConst : TupleBufferView {
using TupleBufferView::TupleBufferView;
using iterator = forward_iterator<std::tuple<int>*>;
constexpr auto begin() const { return iterator{buffer_}; }
constexpr auto end() const { return iterator{buffer_ + size_}; }
constexpr std::size_t size() { return size_; }
};
static_assert(HasSize<std::ranges::elements_view<SizedNonConst, 0>>);
static_assert(!HasSize<const std::ranges::elements_view<SizedNonConst, 0>>);
struct OnlyConstSized : TupleBufferView {
using TupleBufferView::TupleBufferView;
using iterator = forward_iterator<std::tuple<int>*>;
constexpr auto begin() const { return iterator{buffer_}; }
constexpr auto end() const { return iterator{buffer_ + size_}; }
constexpr std::size_t size() const { return size_; }
constexpr std::size_t size() = delete;
};
static_assert(HasSize<const OnlyConstSized>);
static_assert(HasSize<std::ranges::elements_view<OnlyConstSized, 0>>);
static_assert(HasSize<const std::ranges::elements_view<OnlyConstSized, 0>>);
constexpr bool test() {
std::tuple<int> buffer[] = {{1}, {2}, {3}};
// non-const and const are sized
{
auto ev = std::views::elements<0>(buffer);
assert(ev.size() == 3);
assert(std::as_const(ev).size() == 3);
}
{
// const-view non-sized range
auto ev = std::views::elements<0>(SizedNonConst{buffer});
assert(ev.size() == 3);
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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