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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-no-concepts
// UNSUPPORTED: gcc-10
// UNSUPPORTED: libcpp-has-no-incomplete-ranges
// constexpr auto begin();
// constexpr auto begin() const requires range<const V>;
#include <ranges>
#include <cassert>
#include "test_macros.h"
#include "test_iterators.h"
#include "test_range.h"
struct ContiguousView : std::ranges::view_base {
int *ptr_;
constexpr ContiguousView(int* ptr) : ptr_(ptr) {}
constexpr ContiguousView(ContiguousView&&) = default;
constexpr ContiguousView& operator=(ContiguousView&&) = default;
friend constexpr int* begin(ContiguousView& view) { return view.ptr_; }
friend constexpr int* begin(ContiguousView const& view) { return view.ptr_; }
friend constexpr sentinel_wrapper<int*> end(ContiguousView& view) {
return sentinel_wrapper<int*>{view.ptr_ + 8};
}
friend constexpr sentinel_wrapper<int*> end(ContiguousView const& view) {
return sentinel_wrapper<int*>{view.ptr_ + 8};
}
};
struct CopyableView : std::ranges::view_base {
int *ptr_;
constexpr CopyableView(int* ptr) : ptr_(ptr) {}
friend constexpr int* begin(CopyableView& view) { return view.ptr_; }
friend constexpr int* begin(CopyableView const& view) { return view.ptr_; }
friend constexpr sentinel_wrapper<int*> end(CopyableView& view) {
return sentinel_wrapper<int*>{view.ptr_ + 8};
}
friend constexpr sentinel_wrapper<int*> end(CopyableView const& view) {
return sentinel_wrapper<int*>{view.ptr_ + 8};
}
};
struct MutableView : std::ranges::view_base {
int *ptr_;
constexpr MutableView(int* ptr) : ptr_(ptr) {}
constexpr int* begin() { return ptr_; }
constexpr sentinel_wrapper<int*> end() { return sentinel_wrapper<int*>{ptr_ + 8}; }
};
using ForwardIter = forward_iterator<int*>;
struct SizedForwardView : std::ranges::view_base {
int *ptr_;
constexpr SizedForwardView(int* ptr) : ptr_(ptr) {}
friend constexpr ForwardIter begin(SizedForwardView& view) { return ForwardIter(view.ptr_); }
friend constexpr ForwardIter begin(SizedForwardView const& view) { return ForwardIter(view.ptr_); }
friend constexpr sentinel_wrapper<ForwardIter> end(SizedForwardView& view) {
return sentinel_wrapper<ForwardIter>{ForwardIter(view.ptr_ + 8)};
}
friend constexpr sentinel_wrapper<ForwardIter> end(SizedForwardView const& view) {
return sentinel_wrapper<ForwardIter>{ForwardIter(view.ptr_ + 8)};
}
};
// Required to make SizedForwardView a sized view.
constexpr auto operator-(sentinel_wrapper<ForwardIter> sent, ForwardIter iter) {
return sent.base().base() - iter.base();
}
constexpr auto operator-(ForwardIter iter, sentinel_wrapper<ForwardIter> sent) {
return iter.base() - sent.base().base();
}
using RandomAccessIter = random_access_iterator<int*>;
struct SizedRandomAccessView : std::ranges::view_base {
int *ptr_;
constexpr SizedRandomAccessView(int* ptr) : ptr_(ptr) {}
friend constexpr RandomAccessIter begin(SizedRandomAccessView& view) { return RandomAccessIter(view.ptr_); }
friend constexpr RandomAccessIter begin(SizedRandomAccessView const& view) { return RandomAccessIter(view.ptr_); }
friend constexpr sentinel_wrapper<RandomAccessIter> end(SizedRandomAccessView& view) {
return sentinel_wrapper<RandomAccessIter>{RandomAccessIter(view.ptr_ + 8)};
}
friend constexpr sentinel_wrapper<RandomAccessIter> end(SizedRandomAccessView const& view) {
return sentinel_wrapper<RandomAccessIter>{RandomAccessIter(view.ptr_ + 8)};
}
};
// Required to make SizedRandomAccessView a sized view.
constexpr auto operator-(sentinel_wrapper<RandomAccessIter> sent, RandomAccessIter iter) {
return sent.base().base() - iter.base();
}
constexpr auto operator-(RandomAccessIter iter, sentinel_wrapper<RandomAccessIter> sent) {
return iter.base() - sent.base().base();
}
template<class T>
concept BeginEnabled = requires(const std::ranges::common_view<T>& comm) {
comm.begin();
};
constexpr bool test() {
int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
{
static_assert( BeginEnabled<CopyableView>);
static_assert(!BeginEnabled<MutableView>);
}
{
std::ranges::common_view<SizedRandomAccessView> comm(SizedRandomAccessView{buffer});
assert(comm.begin() == begin(SizedRandomAccessView(buffer)));
ASSERT_SAME_TYPE(decltype(comm.begin()), RandomAccessIter);
}
{
const std::ranges::common_view<SizedRandomAccessView> comm(SizedRandomAccessView{buffer});
assert(comm.begin() == begin(SizedRandomAccessView(buffer)));
ASSERT_SAME_TYPE(decltype(comm.begin()), RandomAccessIter);
}
return true;
}
int main(int, char**) {
test();
static_assert(test());
// The non-constexpr tests:
int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
{
std::ranges::common_view<SizedForwardView> comm(SizedForwardView{buffer});
assert(comm.begin() == begin(SizedForwardView(buffer)));
ASSERT_SAME_TYPE(decltype(comm.begin()), std::common_iterator<ForwardIter, sentinel_wrapper<ForwardIter>>);
}
{
std::ranges::common_view<ContiguousView> comm(ContiguousView{buffer});
assert(comm.begin() == begin(ContiguousView(buffer)));
ASSERT_SAME_TYPE(decltype(comm.begin()), std::common_iterator<int*, sentinel_wrapper<int*>>);
}
{
const std::ranges::common_view<SizedForwardView> comm(SizedForwardView{buffer});
assert(comm.begin() == begin(SizedForwardView(buffer)));
ASSERT_SAME_TYPE(decltype(comm.begin()), std::common_iterator<ForwardIter, sentinel_wrapper<ForwardIter>>);
}
{
const std::ranges::common_view<CopyableView> comm(CopyableView{buffer});
assert(comm.begin() == begin(CopyableView(buffer)));
ASSERT_SAME_TYPE(decltype(comm.begin()), std::common_iterator<int*, sentinel_wrapper<int*>>);
}
return 0;
}
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