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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
// UNSUPPORTED: libcpp-has-no-incomplete-ranges
// template<bool OtherConst>
// requires sentinel_for<sentinel_t<Base>, iterator_t<maybe-const<OtherConst, V>>>
// friend constexpr bool operator==(const iterator<OtherConst>& x, const sentinel& y);
#include <cassert>
#include <concepts>
#include <functional>
#include <ranges>
#include "../types.h"
template <class Iter, class Sent>
concept EqualityComparable = std::invocable<std::equal_to<>, const Iter&, const Sent&> ;
using Iterator = random_access_iterator<BufferView<int*>*>;
using ConstIterator = random_access_iterator<const BufferView<int*>*>;
template <bool Const>
struct ConstComparableSentinel {
using Iter = std::conditional_t<Const, ConstIterator, Iterator>;
Iter iter_;
explicit ConstComparableSentinel() = default;
constexpr explicit ConstComparableSentinel(const Iter& it) : iter_(it) {}
constexpr friend bool operator==(const Iterator& i, const ConstComparableSentinel& s) {
return base(i) == base(s.iter_);
}
constexpr friend bool operator==(const ConstIterator& i, const ConstComparableSentinel& s) {
return base(i) == base(s.iter_);
}
};
struct ConstComparableView : BufferView<BufferView<int*>*> {
using BufferView<BufferView<int*>*>::BufferView;
constexpr auto begin() { return Iterator(data_); }
constexpr auto begin() const { return ConstIterator(data_); }
constexpr auto end() { return ConstComparableSentinel<false>(Iterator(data_ + size_)); }
constexpr auto end() const { return ConstComparableSentinel<true>(ConstIterator(data_ + size_)); }
};
static_assert(EqualityComparable<std::ranges::iterator_t<ConstComparableView>,
std::ranges::sentinel_t<const ConstComparableView>>);
static_assert(EqualityComparable<std::ranges::iterator_t<const ConstComparableView>,
std::ranges::sentinel_t<ConstComparableView>>);
constexpr bool test() {
int buffer[4][4] = {{1111, 2222, 3333, 4444}, {555, 666, 777, 888}, {99, 1010, 1111, 1212}, {13, 14, 15, 16}};
{
ChildView children[4] = {ChildView(buffer[0]), ChildView(buffer[1]), ChildView(buffer[2]), ChildView(buffer[3])};
auto jv = std::ranges::join_view(ParentView(children));
assert(jv.end() == std::ranges::next(jv.begin(), 16));
static_assert(!EqualityComparable<decltype(std::as_const(jv).begin()), decltype(jv.end())>);
static_assert(!EqualityComparable<decltype(jv.begin()), decltype(std::as_const(jv).end())>);
}
{
CopyableChild children[4] = {CopyableChild(buffer[0]), CopyableChild(buffer[1]), CopyableChild(buffer[2]),
CopyableChild(buffer[3])};
const auto jv = std::ranges::join_view(ParentView(children));
assert(jv.end() == std::ranges::next(jv.begin(), 16));
}
// test iterator<Const> == sentinel<!Const>
{
BufferView<int*> inners[] = {buffer[0], buffer[1]};
ConstComparableView outer(inners);
auto jv = std::ranges::join_view(outer);
assert(jv.end() == std::ranges::next(jv.begin(), 8));
assert(std::as_const(jv).end() == std::ranges::next(jv.begin(), 8));
assert(jv.end() == std::ranges::next(std::as_const(jv).begin(), 8));
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
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