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 * modification, are permitted provided that the following conditions are met:
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 *       notice, this list of conditions and the following disclaimer.
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 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
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#pragma once

#if THRUST_DEVICE_COMPILER == THRUST_DEVICE_COMPILER_HIP
#include <iterator>
#include <thrust/distance.h>
#include <thrust/system/hip/detail/scan.h>

// rocprim include
#include <rocprim/rocprim.hpp>
#include <thrust/detail/alignment.h>
#include <thrust/detail/cstdint.h>

THRUST_NAMESPACE_BEGIN

namespace hip_rocprim
{

template <class Derived, class InputIt, class OutputIt, class TransformOp, class ScanOp>
OutputIt
transform_inclusive_scan(execution_policy<Derived>& policy,
                         InputIt                    first,
                         InputIt                    last,
                         OutputIt                   result,
                         TransformOp                transform_op,
                         ScanOp                     scan_op)
{
    // Use the input iterator's value type per https://wg21.link/P0571
    using input_type = typename thrust::iterator_value<InputIt>::type;
#if THRUST_CPP_DIALECT < 2017
    using result_type = typename std::result_of<TransformOp(input_type)>::type;
#else
    using result_type = std::invoke_result_t<TransformOp, input_type>;
#endif

    using value_type = typename std::remove_reference<result_type>::type;

    typedef typename iterator_traits<InputIt>::difference_type size_type;
    size_type num_items = static_cast<size_type>(thrust::distance(first, last));
    typedef transform_input_iterator_t<value_type, InputIt, TransformOp>
        transformed_iterator_t;

    return hip_rocprim::inclusive_scan_n(
        policy,
        transformed_iterator_t(first, transform_op),
        num_items,
        result,
        scan_op
    );
}

template <class Derived,
          class InputIt,
          class OutputIt,
          class TransformOp,
          class InitialValueType,
          class ScanOp>
OutputIt
transform_exclusive_scan(execution_policy<Derived>& policy,
                         InputIt                    first,
                         InputIt                    last,
                         OutputIt                   result,
                         TransformOp                transform_op,
                         InitialValueType                          init,
                         ScanOp                     scan_op)
{
    // Use the initial value type per https://wg21.link/P0571
    using result_type = typename std::remove_reference<InitialValueType>::type;

    typedef typename iterator_traits<InputIt>::difference_type size_type;
    size_type num_items = static_cast<size_type>(thrust::distance(first, last));
    typedef transform_input_iterator_t<result_type, InputIt, TransformOp>
        transformed_iterator_t;

    return hip_rocprim::exclusive_scan_n(
        policy,
        transformed_iterator_t(first, transform_op),
        num_items,
        result, init,
        scan_op
    );
}

} // namespace hip_rocprim

THRUST_NAMESPACE_END
#endif