| //===----------------------------------------------------------------------===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // <algorithm> |
| |
| // UNSUPPORTED: c++03, c++11, c++14, c++17 |
| // TODO: make `join_view` non-experimental once D2770 is implemented. |
| // UNSUPPORTED: !c++experimental |
| |
| // template<bidirectional_iterator I1, sentinel_for<I1> S1, bidirectional_iterator I2> |
| // requires indirectly_copyable<I1, I2> |
| // constexpr ranges::copy_backward_result<I1, I2> |
| // ranges::copy_backward(I1 first, S1 last, I2 result); |
| // template<bidirectional_range R, bidirectional_iterator I> |
| // requires indirectly_copyable<iterator_t<R>, I> |
| // constexpr ranges::copy_backward_result<borrowed_iterator_t<R>, I> |
| // ranges::copy_backward(R&& r, I result); |
| |
| #include <algorithm> |
| #include <array> |
| #include <cassert> |
| #include <deque> |
| #include <ranges> |
| #include <vector> |
| |
| #include "almost_satisfies_types.h" |
| #include "test_iterators.h" |
| |
| template <class In, class Out = In, class Sent = sentinel_wrapper<In>> |
| concept HasCopyBackwardIt = requires(In in, Sent sent, Out out) { std::ranges::copy_backward(in, sent, out); }; |
| |
| static_assert(HasCopyBackwardIt<int*>); |
| static_assert(!HasCopyBackwardIt<InputIteratorNotDerivedFrom>); |
| static_assert(!HasCopyBackwardIt<InputIteratorNotIndirectlyReadable>); |
| static_assert(!HasCopyBackwardIt<InputIteratorNotInputOrOutputIterator>); |
| static_assert(!HasCopyBackwardIt<int*, WeaklyIncrementableNotMovable>); |
| struct NotIndirectlyCopyable {}; |
| static_assert(!HasCopyBackwardIt<int*, NotIndirectlyCopyable*>); |
| static_assert(!HasCopyBackwardIt<int*, int*, SentinelForNotSemiregular>); |
| static_assert(!HasCopyBackwardIt<int*, int*, SentinelForNotWeaklyEqualityComparableWith>); |
| |
| template <class Range, class Out> |
| concept HasCopyBackwardR = requires(Range range, Out out) { std::ranges::copy_backward(range, out); }; |
| |
| static_assert(HasCopyBackwardR<std::array<int, 10>, int*>); |
| static_assert(!HasCopyBackwardR<InputRangeNotDerivedFrom, int*>); |
| static_assert(!HasCopyBackwardR<InputRangeNotIndirectlyReadable, int*>); |
| static_assert(!HasCopyBackwardR<InputRangeNotInputOrOutputIterator, int*>); |
| static_assert(!HasCopyBackwardR<WeaklyIncrementableNotMovable, int*>); |
| static_assert(!HasCopyBackwardR<UncheckedRange<NotIndirectlyCopyable*>, int*>); |
| static_assert(!HasCopyBackwardR<InputRangeNotSentinelSemiregular, int*>); |
| static_assert(!HasCopyBackwardR<InputRangeNotSentinelEqualityComparableWith, int*>); |
| |
| static_assert(std::is_same_v<std::ranges::copy_result<int, long>, std::ranges::in_out_result<int, long>>); |
| |
| template <class In, class Out, class Sent> |
| constexpr void test_iterators() { |
| { // simple test |
| { |
| std::array in {1, 2, 3, 4}; |
| std::array<int, 4> out; |
| std::same_as<std::ranges::in_out_result<In, Out>> auto ret = |
| std::ranges::copy_backward(In(in.data()), Sent(In(in.data() + in.size())), Out(out.data() + out.size())); |
| assert(in == out); |
| assert(base(ret.in) == in.data() + in.size()); |
| assert(base(ret.out) == out.data()); |
| } |
| { |
| std::array in {1, 2, 3, 4}; |
| std::array<int, 4> out; |
| auto range = std::ranges::subrange(In(in.data()), Sent(In(in.data() + in.size()))); |
| std::same_as<std::ranges::in_out_result<In, Out>> auto ret = |
| std::ranges::copy_backward(range, Out(out.data() + out.size())); |
| assert(in == out); |
| assert(base(ret.in) == in.data() + in.size()); |
| assert(base(ret.out) == out.data()); |
| } |
| } |
| |
| { // check that an empty range works |
| { |
| std::array<int, 0> in; |
| std::array<int, 0> out; |
| auto ret = |
| std::ranges::copy_backward(In(in.data()), Sent(In(in.data() + in.size())), Out(out.data() + out.size())); |
| assert(base(ret.in) == in.data() + in.size()); |
| assert(base(ret.out) == out.data()); |
| } |
| { |
| std::array<int, 0> in; |
| std::array<int, 0> out; |
| auto range = std::ranges::subrange(In(in.data()), Sent(In(in.data() + in.size()))); |
| auto ret = std::ranges::copy_backward(range, Out(out.data())); |
| assert(base(ret.in) == in.data() + in.size()); |
| assert(base(ret.out) == out.data()); |
| } |
| } |
| } |
| |
| template <class InContainer, class OutContainer, class In, class Out, class Sent = In> |
| constexpr void test_containers() { |
| { |
| InContainer in {1, 2, 3, 4}; |
| OutContainer out(4); |
| std::same_as<std::ranges::in_out_result<In, Out>> auto ret = |
| std::ranges::copy_backward(In(in.begin()), Sent(In(in.end())), Out(out.end())); |
| assert(std::ranges::equal(in, out)); |
| assert(base(ret.in) == in.end()); |
| assert(base(ret.out) == out.begin()); |
| } |
| { |
| InContainer in {1, 2, 3, 4}; |
| OutContainer out(4); |
| auto range = std::ranges::subrange(In(in.begin()), Sent(In(in.end()))); |
| std::same_as<std::ranges::in_out_result<In, Out>> auto ret = std::ranges::copy_backward(range, Out(out.end())); |
| assert(std::ranges::equal(in, out)); |
| assert(base(ret.in) == in.end()); |
| assert(base(ret.out) == out.begin()); |
| } |
| } |
| |
| template <class Iter, class Sent> |
| constexpr void test_join_view() { |
| auto to_subranges = std::views::transform([](auto& vec) { |
| return std::ranges::subrange(Iter(vec.begin()), Sent(Iter(vec.end()))); |
| }); |
| |
| { // segmented -> contiguous |
| std::vector<std::vector<int>> vectors = {}; |
| auto range = vectors | to_subranges; |
| std::vector<std::ranges::subrange<Iter, Sent>> subrange_vector(range.begin(), range.end()); |
| std::array<int, 0> arr; |
| |
| std::ranges::copy_backward(subrange_vector | std::views::join, arr.end()); |
| assert(std::ranges::equal(arr, std::array<int, 0>{})); |
| } |
| { // segmented -> contiguous |
| std::vector<std::vector<int>> vectors = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10}, {}}; |
| auto range = vectors | to_subranges; |
| std::vector<std::ranges::subrange<Iter, Sent>> subrange_vector(range.begin(), range.end()); |
| std::array<int, 10> arr; |
| |
| std::ranges::copy_backward(subrange_vector | std::views::join, arr.end()); |
| assert(std::ranges::equal(arr, std::array{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})); |
| } |
| { // contiguous -> segmented |
| std::vector<std::vector<int>> vectors = {{0, 0, 0, 0}, {0, 0}, {0, 0, 0, 0}, {}}; |
| auto range = vectors | to_subranges; |
| std::vector<std::ranges::subrange<Iter, Sent>> subrange_vector(range.begin(), range.end()); |
| std::array arr = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; |
| |
| std::ranges::copy_backward(arr, (subrange_vector | std::views::join).end()); |
| assert(std::ranges::equal(subrange_vector | std::views::join, std::array{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})); |
| } |
| { // segmented -> segmented |
| std::vector<std::vector<int>> vectors = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10}, {}}; |
| auto range1 = vectors | to_subranges; |
| std::vector<std::ranges::subrange<Iter, Sent>> subrange_vector(range1.begin(), range1.end()); |
| std::vector<std::vector<int>> to_vectors = {{0, 0, 0, 0}, {0, 0, 0, 0}, {}, {0, 0}}; |
| auto range2 = to_vectors | to_subranges; |
| std::vector<std::ranges::subrange<Iter, Sent>> to_subrange_vector(range2.begin(), range2.end()); |
| |
| std::ranges::copy_backward(subrange_vector | std::views::join, (to_subrange_vector | std::views::join).end()); |
| assert(std::ranges::equal(to_subrange_vector | std::views::join, std::array{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})); |
| } |
| } |
| |
| template <class> |
| constexpr bool is_proxy_iterator = false; |
| |
| template <class Iter> |
| constexpr bool is_proxy_iterator<ProxyIterator<Iter>> = true; |
| |
| template <template <class> class InIter, template <class> class OutIter> |
| constexpr void test_sentinels() { |
| test_iterators<InIter<int*>, OutIter<int*>, InIter<int*>>(); |
| test_iterators<InIter<int*>, OutIter<int*>, sentinel_wrapper<InIter<int*>>>(); |
| test_iterators<InIter<int*>, OutIter<int*>, sized_sentinel<InIter<int*>>>(); |
| |
| if constexpr (!std::is_same_v<InIter<int*>, contiguous_iterator<int*>> && |
| !std::is_same_v<OutIter<int*>, contiguous_iterator<int*>> && |
| !std::is_same_v<InIter<int*>, ContiguousProxyIterator<int*>> && |
| !std::is_same_v<OutIter<int*>, ContiguousProxyIterator<int*>>) { |
| if (!std::is_constant_evaluated()) { |
| test_containers<std::deque<int>, |
| std::deque<int>, |
| InIter<std::deque<int>::iterator>, |
| OutIter<std::deque<int>::iterator>>(); |
| test_containers<std::deque<int>, |
| std::vector<int>, |
| InIter<std::deque<int>::iterator>, |
| OutIter<std::vector<int>::iterator>>(); |
| test_containers<std::vector<int>, |
| std::deque<int>, |
| InIter<std::vector<int>::iterator>, |
| OutIter<std::deque<int>::iterator>>(); |
| test_containers<std::vector<int>, |
| std::vector<int>, |
| InIter<std::vector<int>::iterator>, |
| OutIter<std::vector<int>::iterator>>(); |
| } |
| if constexpr (!is_proxy_iterator<InIter<int*>>) |
| test_join_view<InIter<std::vector<int>::iterator>, InIter<std::vector<int>::iterator>>(); |
| } |
| } |
| |
| template <template <class> class Out> |
| constexpr void test_in_iterators() { |
| test_sentinels<bidirectional_iterator, Out>(); |
| test_sentinels<random_access_iterator, Out>(); |
| test_sentinels<contiguous_iterator, Out>(); |
| test_sentinels<std::type_identity_t, Out>(); |
| } |
| |
| template <template <class> class Out> |
| constexpr void test_proxy_in_iterators() { |
| test_sentinels<BidirectionalProxyIterator, Out>(); |
| test_sentinels<RandomAccessProxyIterator, Out>(); |
| test_sentinels<ContiguousProxyIterator, Out>(); |
| test_sentinels<ProxyIterator, Out>(); |
| } |
| |
| constexpr bool test() { |
| test_in_iterators<bidirectional_iterator>(); |
| test_in_iterators<random_access_iterator>(); |
| test_in_iterators<contiguous_iterator>(); |
| test_in_iterators<std::type_identity_t>(); |
| |
| test_proxy_in_iterators<BidirectionalProxyIterator>(); |
| test_proxy_in_iterators<RandomAccessProxyIterator>(); |
| test_proxy_in_iterators<ContiguousProxyIterator>(); |
| |
| { // check that ranges::dangling is returned |
| std::array<int, 4> out; |
| std::same_as<std::ranges::in_out_result<std::ranges::dangling, int*>> auto ret = |
| std::ranges::copy_backward(std::array {1, 2, 3, 4}, out.data() + out.size()); |
| assert(ret.out == out.data()); |
| assert((out == std::array{1, 2, 3, 4})); |
| } |
| |
| { // check that an iterator is returned with a borrowing range |
| std::array in {1, 2, 3, 4}; |
| std::array<int, 4> out; |
| std::same_as<std::ranges::in_out_result<int*, int*>> auto ret = |
| std::ranges::copy_backward(std::views::all(in), out.data() + out.size()); |
| assert(ret.in == in.data() + in.size()); |
| assert(ret.out == out.data()); |
| assert(in == out); |
| } |
| |
| { // check that every element is copied exactly once |
| struct CopyOnce { |
| bool copied = false; |
| constexpr CopyOnce() = default; |
| constexpr CopyOnce(const CopyOnce& other) = delete; |
| constexpr CopyOnce& operator=(const CopyOnce& other) { |
| assert(!other.copied); |
| copied = true; |
| return *this; |
| } |
| }; |
| { |
| std::array<CopyOnce, 4> in {}; |
| std::array<CopyOnce, 4> out {}; |
| auto ret = std::ranges::copy_backward(in.begin(), in.end(), out.end()); |
| assert(ret.in == in.end()); |
| assert(ret.out == out.begin()); |
| assert(std::all_of(out.begin(), out.end(), [](const auto& e) { return e.copied; })); |
| } |
| { |
| std::array<CopyOnce, 4> in {}; |
| std::array<CopyOnce, 4> out {}; |
| auto ret = std::ranges::copy_backward(in, out.end()); |
| assert(ret.in == in.end()); |
| assert(ret.out == out.begin()); |
| assert(std::all_of(out.begin(), out.end(), [](const auto& e) { return e.copied; })); |
| } |
| } |
| |
| { // check that the range is copied backwards |
| struct OnlyBackwardsCopyable { |
| OnlyBackwardsCopyable* next = nullptr; |
| bool canCopy = false; |
| OnlyBackwardsCopyable() = default; |
| constexpr OnlyBackwardsCopyable& operator=(const OnlyBackwardsCopyable&) { |
| assert(canCopy); |
| if (next != nullptr) |
| next->canCopy = true; |
| return *this; |
| } |
| }; |
| { |
| std::array<OnlyBackwardsCopyable, 3> in {}; |
| std::array<OnlyBackwardsCopyable, 3> out {}; |
| out[1].next = &out[0]; |
| out[2].next = &out[1]; |
| out[2].canCopy = true; |
| auto ret = std::ranges::copy_backward(in, out.end()); |
| assert(ret.in == in.end()); |
| assert(ret.out == out.begin()); |
| assert(out[0].canCopy); |
| assert(out[1].canCopy); |
| assert(out[2].canCopy); |
| } |
| { |
| std::array<OnlyBackwardsCopyable, 3> in {}; |
| std::array<OnlyBackwardsCopyable, 3> out {}; |
| out[1].next = &out[0]; |
| out[2].next = &out[1]; |
| out[2].canCopy = true; |
| auto ret = std::ranges::copy_backward(in.begin(), in.end(), out.end()); |
| assert(ret.in == in.end()); |
| assert(ret.out == out.begin()); |
| assert(out[0].canCopy); |
| assert(out[1].canCopy); |
| assert(out[2].canCopy); |
| } |
| } |
| |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| static_assert(test()); |
| |
| return 0; |
| } |