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#pragma once

#if THRUST_DEVICE_COMPILER == THRUST_DEVICE_COMPILER_HIP
#include <thrust/system/hip/detail/execution_policy.h>

THRUST_NAMESPACE_BEGIN
namespace hip_rocprim
{
    template <class Derived, class ItemsIt, class ResultIt>
    ResultIt __host__ __device__
    reverse_copy(execution_policy<Derived>& policy,
                 ItemsIt                    first,
                 ItemsIt                    last,
                 ResultIt                   result);

    template <class Derived, class ItemsIt>
    void __host__ __device__
    reverse(execution_policy<Derived>& policy,
            ItemsIt                    first,
            ItemsIt                    last);
} // namespace hip_rocprim
THRUST_NAMESPACE_END

#include <thrust/advance.h>
#include <thrust/distance.h>
#include <thrust/iterator/reverse_iterator.h>
#include <thrust/system/hip/detail/copy.h>
#include <thrust/system/hip/detail/swap_ranges.h>

THRUST_NAMESPACE_BEGIN
namespace hip_rocprim
{
    template <class Derived, class ItemsIt, class ResultIt>
    ResultIt THRUST_HIP_FUNCTION
    reverse_copy(execution_policy<Derived>& policy,
                 ItemsIt                    first,
                 ItemsIt                    last,
                 ResultIt                   result)
    {
        return hip_rocprim::copy(
            policy, thrust::make_reverse_iterator(last), thrust::make_reverse_iterator(first), result
        );
    }

    template <class Derived, class ItemsIt>
    void THRUST_HIP_FUNCTION
    reverse(execution_policy<Derived>& policy, ItemsIt first, ItemsIt last)
    {
        typedef typename thrust::iterator_difference<ItemsIt>::type difference_type;

        // find the midpoint of [first,last)
        difference_type N = thrust::distance(first, last);
        ItemsIt         mid(first);
        thrust::advance(mid, N / 2);

        hip_rocprim::swap_ranges(policy, first, mid, thrust::make_reverse_iterator(last));
    }
} // namespace hip_rocprim
THRUST_NAMESPACE_END
#endif
