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/*
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

/*! \file thrust/system/hip/hipstdpar/impl/generation.hpp
 *  \brief <tt>Generation operations</tt> implementation detail header for HIPSTDPAR.
 */

#pragma once

#if defined(__HIPSTDPAR__)

#  include <thrust/execution_policy.h>
#  include <thrust/fill.h>
#  include <thrust/generate.h>

#  include <algorithm>
#  include <execution>
#  include <type_traits>
#  include <utility>

#  include "hipstd.hpp"

namespace std
{
// BEGIN FILL
template <typename I, typename T, enable_if_t<::hipstd::is_offloadable_iterator<I>()>* = nullptr>
inline void fill(execution::parallel_unsequenced_policy, I f, I l, const T& x)
{
  return ::thrust::fill(::thrust::device, f, l, x);
}

template <typename I, typename T, enable_if_t<!::hipstd::is_offloadable_iterator<I>()>* = nullptr>
inline void fill(execution::parallel_unsequenced_policy, I f, I l, const T& x)
{
  ::hipstd::unsupported_iterator_category<typename iterator_traits<I>::iterator_category>();

  return ::std::fill(::std::execution::par, f, l, x);
}
// END FILL

// BEGIN FILL_N
template <typename I, typename N, typename T, enable_if_t<::hipstd::is_offloadable_iterator<I>()>* = nullptr>
inline void fill_n(execution::parallel_unsequenced_policy, I f, N n, const T& x)
{
  return ::thrust::fill_n(::thrust::device, f, n, x);
}

template <typename I, typename N, typename T, enable_if_t<!::hipstd::is_offloadable_iterator<I>()>* = nullptr>
inline void fill_n(execution::parallel_unsequenced_policy, I f, N n, const T& x)
{
  ::hipstd::unsupported_iterator_category<typename iterator_traits<I>::iterator_category>();

  return ::std::fill_n(::std::execution::par, f, n, x);
}
// END FILL_N

// BEGIN GENERATE
template <typename I,
          typename G,
          enable_if_t<::hipstd::is_offloadable_iterator<I>() && ::hipstd::is_offloadable_callable<G>()>* = nullptr>
inline void generate(execution::parallel_unsequenced_policy, I f, I l, G g)
{
  using g_t = ::std::decay_t<G>;

  if constexpr (::std::is_trivially_destructible_v<g_t>)
  {
    ::thrust::generate(::thrust::device, f, l, ::std::move(g));
  }
  else
  {
    ::hipstd::detail::device_callable_guard<g_t> guard(::std::move(g));
    try
    {
      ::thrust::generate(::thrust::device, f, l, ::hipstd::detail::callable_proxy<g_t>{guard.get()});
    }
    catch (...)
    {
      (void) ::hipDeviceSynchronize();
      throw;
    }
    ::thrust::hip_rocprim::throw_on_error(::hipDeviceSynchronize(), "hipstdpar generate: failed to synchronize");
    guard.destroy_and_free();
  }
}

template <typename I,
          typename G,
          enable_if_t<!::hipstd::is_offloadable_iterator<I>() || !::hipstd::is_offloadable_callable<G>()>* = nullptr>
inline void generate(execution::parallel_unsequenced_policy, I f, I l, G g)
{
  if constexpr (!::hipstd::is_offloadable_iterator<I>())
  {
    ::hipstd::unsupported_iterator_category<typename iterator_traits<I>::iterator_category>();
  }
  if constexpr (!::hipstd::is_offloadable_callable<G>())
  {
    ::hipstd::unsupported_callable_type<G>();
  }

  return ::std::generate(::std::execution::par, f, l, ::std::move(g));
}
// END GENERATE

// BEGIN GENERATE_N
template <typename I,
          typename N,
          typename G,
          enable_if_t<::hipstd::is_offloadable_iterator<I>() && ::hipstd::is_offloadable_callable<G>()>* = nullptr>
inline void generate_n(execution::parallel_unsequenced_policy, I f, N n, G g)
{
  using g_t = ::std::decay_t<G>;

  if constexpr (::std::is_trivially_destructible_v<g_t>)
  {
    ::thrust::generate_n(::thrust::device, f, n, ::std::move(g));
  }
  else
  {
    ::hipstd::detail::device_callable_guard<g_t> guard(::std::move(g));
    try
    {
      ::thrust::generate_n(::thrust::device, f, n, ::hipstd::detail::callable_proxy<g_t>{guard.get()});
    }
    catch (...)
    {
      (void) ::hipDeviceSynchronize();
      throw;
    }
    ::thrust::hip_rocprim::throw_on_error(::hipDeviceSynchronize(), "hipstdpar generate_n: failed to synchronize");
    guard.destroy_and_free();
  }
}

template <typename I,
          typename N,
          typename G,
          enable_if_t<!::hipstd::is_offloadable_iterator<I>() || !::hipstd::is_offloadable_callable<G>()>* = nullptr>
inline void generate_n(execution::parallel_unsequenced_policy, I f, N n, G g)
{
  if constexpr (!::hipstd::is_offloadable_iterator<I>())
  {
    ::hipstd::unsupported_iterator_category<typename iterator_traits<I>::iterator_category>();
  }
  if constexpr (!::hipstd::is_offloadable_callable<G>())
  {
    ::hipstd::unsupported_callable_type<G>();
  }

  return ::std::generate_n(::std::execution::par, f, n, ::std::move(g));
}
// END GENERATE_N
} // namespace std
#else // __HIPSTDPAR__
#  error "__HIPSTDPAR__ should be defined. Please use the '--hipstdpar' compile option."
#endif // __HIPSTDPAR__
