| //===----------------------------------------------------------------------===// |
| // |
| // 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 |
| |
| // template<bidirectional_iterator I1, sentinel_for<I1> S1, bidirectional_iterator I2> |
| // requires indirectly_movable<I1, I2> |
| // constexpr ranges::move_backward_result<I1, I2> |
| // ranges::move_backward(I1 first, S1 last, I2 result); |
| // template<bidirectional_range R, bidirectional_iterator I> |
| // requires indirectly_movable<iterator_t<R>, I> |
| // constexpr ranges::move_backward_result<borrowed_iterator_t<R>, I> |
| // ranges::move_backward(R&& r, I result); |
| |
| #include <algorithm> |
| #include <array> |
| #include <cassert> |
| #include <deque> |
| #include <ranges> |
| #include <vector> |
| |
| #include "almost_satisfies_types.h" |
| #include "MoveOnly.h" |
| #include "test_iterators.h" |
| |
| template <class In, class Out = In, class Sent = sentinel_wrapper<In>> |
| concept HasMoveBackwardIt = requires(In in, Sent sent, Out out) { std::ranges::move_backward(in, sent, out); }; |
| |
| static_assert(HasMoveBackwardIt<int*>); |
| static_assert(!HasMoveBackwardIt<InputIteratorNotDerivedFrom>); |
| static_assert(!HasMoveBackwardIt<InputIteratorNotIndirectlyReadable>); |
| static_assert(!HasMoveBackwardIt<InputIteratorNotInputOrOutputIterator>); |
| static_assert(!HasMoveBackwardIt<int*, WeaklyIncrementableNotMovable>); |
| struct NotIndirectlyCopyable {}; |
| static_assert(!HasMoveBackwardIt<int*, NotIndirectlyCopyable*>); |
| static_assert(!HasMoveBackwardIt<int*, int*, SentinelForNotSemiregular>); |
| static_assert(!HasMoveBackwardIt<int*, int*, SentinelForNotWeaklyEqualityComparableWith>); |
| |
| template <class Range, class Out> |
| concept HasMoveBackwardR = requires(Range range, Out out) { std::ranges::move_backward(range, out); }; |
| |
| static_assert(HasMoveBackwardR<std::array<int, 10>, int*>); |
| static_assert(!HasMoveBackwardR<InputRangeNotDerivedFrom, int*>); |
| static_assert(!HasMoveBackwardR<InputRangeNotIndirectlyReadable, int*>); |
| static_assert(!HasMoveBackwardR<InputRangeNotInputOrOutputIterator, int*>); |
| static_assert(!HasMoveBackwardR<WeaklyIncrementableNotMovable, int*>); |
| static_assert(!HasMoveBackwardR<UncheckedRange<NotIndirectlyCopyable*>, int*>); |
| static_assert(!HasMoveBackwardR<InputRangeNotSentinelSemiregular, int*>); |
| static_assert(!HasMoveBackwardR<InputRangeNotSentinelEqualityComparableWith, int*>); |
| static_assert(!HasMoveBackwardR<UncheckedRange<int*>, WeaklyIncrementableNotMovable>); |
| |
| 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, int N> |
| constexpr void test(std::array<int, N> in) { |
| { |
| std::array<int, N> out; |
| std::same_as<std::ranges::in_out_result<In, Out>> decltype(auto) ret = |
| std::ranges::move_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<int, N> 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>> decltype(auto) ret = |
| std::ranges::move_backward(range, Out(out.data() + out.size())); |
| assert(in == out); |
| assert(base(ret.in) == in.data() + in.size()); |
| assert(base(ret.out) == out.data()); |
| } |
| } |
| |
| template <class In, class Out, class Sent = In> |
| constexpr void test_iterators() { |
| // simple test |
| test<In, Out, Sent, 4>({1, 2, 3, 4}); |
| // check that an empty range works |
| test<In, Out, Sent, 0>({}); |
| } |
| |
| 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::move_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::move_backward(range, Out(out.end())); |
| assert(std::ranges::equal(in, out)); |
| assert(base(ret.in) == in.end()); |
| assert(base(ret.out) == out.begin()); |
| } |
| } |
| |
| 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 (!std::is_constant_evaluated()) { |
| 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*>>) { |
| 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>>(); |
| } |
| } |
| } |
| |
| 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>(); |
| } |
| |
| struct IteratorWithMoveIter { |
| using value_type = int; |
| using difference_type = int; |
| explicit IteratorWithMoveIter() = default; |
| int* ptr; |
| constexpr IteratorWithMoveIter(int* ptr_) : ptr(ptr_) {} |
| |
| constexpr int& operator*() const; // iterator with iter_move should not be dereferenced |
| |
| constexpr IteratorWithMoveIter& operator++() { ++ptr; return *this; } |
| constexpr IteratorWithMoveIter operator++(int) { auto ret = *this; ++*this; return ret; } |
| |
| constexpr IteratorWithMoveIter& operator--() { --ptr; return *this; } |
| constexpr IteratorWithMoveIter operator--(int) { auto ret = *this; --*this; return ret; } |
| |
| friend constexpr int iter_move(const IteratorWithMoveIter&) { return 42; } |
| |
| constexpr bool operator==(const IteratorWithMoveIter& other) const = default; |
| }; |
| |
| 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>(); |
| test_proxy_in_iterators<ProxyIterator>(); |
| |
| { // check that a move-only type works |
| { |
| MoveOnly a[] = {1, 2, 3}; |
| MoveOnly b[3]; |
| std::ranges::move_backward(a, std::end(b)); |
| assert(b[0].get() == 1); |
| assert(b[1].get() == 2); |
| assert(b[2].get() == 3); |
| } |
| { |
| MoveOnly a[] = {1, 2, 3}; |
| MoveOnly b[3]; |
| std::ranges::move_backward(std::begin(a), std::end(a), std::end(b)); |
| assert(b[0].get() == 1); |
| assert(b[1].get() == 2); |
| assert(b[2].get() == 3); |
| } |
| } |
| |
| { // check that a move-only type works for ProxyIterator |
| { |
| MoveOnly a[] = {1, 2, 3}; |
| MoveOnly b[3]; |
| ProxyRange proxyA{a}; |
| ProxyRange proxyB{b}; |
| std::ranges::move_backward(proxyA, std::ranges::next(proxyB.begin(), std::end(proxyB))); |
| assert(b[0].get() == 1); |
| assert(b[1].get() == 2); |
| assert(b[2].get() == 3); |
| } |
| { |
| MoveOnly a[] = {1, 2, 3}; |
| MoveOnly b[3]; |
| ProxyRange proxyA{a}; |
| ProxyRange proxyB{b}; |
| std::ranges::move_backward(std::begin(proxyA), std::end(proxyA), std::ranges::next(proxyB.begin(), std::end(proxyB))); |
| assert(b[0].get() == 1); |
| assert(b[1].get() == 2); |
| assert(b[2].get() == 3); |
| } |
| } |
| |
| { // 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::move_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::move_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 moved exactly once |
| struct MoveOnce { |
| bool moved = false; |
| constexpr MoveOnce() = default; |
| constexpr MoveOnce(const MoveOnce& other) = delete; |
| constexpr MoveOnce& operator=(const MoveOnce& other) { |
| assert(!other.moved); |
| moved = true; |
| return *this; |
| } |
| }; |
| { |
| std::array<MoveOnce, 4> in {}; |
| std::array<MoveOnce, 4> out {}; |
| auto ret = std::ranges::move_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.moved; })); |
| } |
| { |
| std::array<MoveOnce, 4> in {}; |
| std::array<MoveOnce, 4> out {}; |
| auto ret = std::ranges::move_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.moved; })); |
| } |
| } |
| |
| { // check that the range is moved backwards |
| struct OnlyBackwardsMovable { |
| OnlyBackwardsMovable* next = nullptr; |
| bool canMove = false; |
| OnlyBackwardsMovable() = default; |
| constexpr OnlyBackwardsMovable& operator=(const OnlyBackwardsMovable&) { |
| assert(canMove); |
| if (next != nullptr) |
| next->canMove = true; |
| return *this; |
| } |
| }; |
| { |
| std::array<OnlyBackwardsMovable, 3> in {}; |
| std::array<OnlyBackwardsMovable, 3> out {}; |
| out[1].next = &out[0]; |
| out[2].next = &out[1]; |
| out[2].canMove = true; |
| auto ret = std::ranges::move_backward(in, out.end()); |
| assert(ret.in == in.end()); |
| assert(ret.out == out.begin()); |
| assert(out[0].canMove); |
| assert(out[1].canMove); |
| assert(out[2].canMove); |
| } |
| { |
| std::array<OnlyBackwardsMovable, 3> in {}; |
| std::array<OnlyBackwardsMovable, 3> out {}; |
| out[1].next = &out[0]; |
| out[2].next = &out[1]; |
| out[2].canMove = true; |
| auto ret = std::ranges::move_backward(in.begin(), in.end(), out.end()); |
| assert(ret.in == in.end()); |
| assert(ret.out == out.begin()); |
| assert(out[0].canMove); |
| assert(out[1].canMove); |
| assert(out[2].canMove); |
| } |
| } |
| |
| { // check that iter_move is used properly |
| { |
| int a[] = {1, 2, 3, 4}; |
| std::array<int, 4> b; |
| auto ret = std::ranges::move_backward(IteratorWithMoveIter(a), IteratorWithMoveIter(a + 4), b.data() + b.size()); |
| assert(ret.in == a + 4); |
| assert(ret.out == b.data()); |
| assert((b == std::array {42, 42, 42, 42})); |
| } |
| { |
| int a[] = {1, 2, 3, 4}; |
| std::array<int, 4> b; |
| auto range = std::ranges::subrange(IteratorWithMoveIter(a), IteratorWithMoveIter(a + 4)); |
| auto ret = std::ranges::move_backward(range, b.data() + b.size()); |
| assert(ret.in == a + 4); |
| assert(ret.out == b.data()); |
| assert((b == std::array {42, 42, 42, 42})); |
| } |
| } |
| |
| return true; |
| } |
| |
| int main(int, char**) { |
| test(); |
| static_assert(test()); |
| |
| return 0; |
| } |