/******************************************************************************
 * Copyright (c) 2016, NVIDIA CORPORATION.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the NVIDIA CORPORATION nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL NVIDIA CORPORATION BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 ******************************************************************************/
#pragma once

#include <thrust/system/cpp/detail/execution_policy.h>
#include <thrust/system/cuda/detail/execution_policy.h>

BEGIN_NS_THRUST
namespace cuda_cub {

  template <class Sys1, class Sys2>
  struct cross_system : thrust::execution_policy<cross_system<Sys1, Sys2> >
  {
    typedef thrust::execution_policy<Sys1> policy1;
    typedef thrust::execution_policy<Sys2> policy2;

    policy1 &sys1;
    policy2 &sys2;

    inline __host__ __device__
    cross_system(policy1 &sys1, policy2 &sys2) : sys1(sys1), sys2(sys2) {}

    __host__ __device__ inline cross_system<Sys2, Sys1>
    rotate() const
    {
      return cross_system<Sys2, Sys1>(sys2, sys1);
    }
  };

  // host interop: (device,host)
  template <class Sys1, class Sys2>
  __host__ __device__ inline cross_system<Sys1, Sys2>
  select_system(execution_policy<Sys1> const &             sys1,
                thrust::cpp::execution_policy<Sys2> const &sys2)
  {
    thrust::execution_policy<Sys1> &     non_const_sys1 = const_cast<execution_policy<Sys1> &>(sys1);
    thrust::cpp::execution_policy<Sys2> &non_const_sys2 = const_cast<thrust::cpp::execution_policy<Sys2> &>(sys2);
    return cross_system<Sys1, Sys2>(non_const_sys1, non_const_sys2);
  }

  // host interop: (host,device)
  template <class Sys1, class Sys2>
  __host__ __device__ inline cross_system<Sys1, Sys2>
  select_system(const thrust::cpp::execution_policy<Sys1> &sys1, execution_policy<Sys2> &sys2)
  {
    thrust::cpp::execution_policy<Sys1> &non_const_sys1 = const_cast<thrust::cpp::execution_policy<Sys1> &>(sys1);
    thrust::execution_policy<Sys2> &     non_const_sys2 = const_cast<execution_policy<Sys2> &>(sys2);
    return cross_system<Sys1, Sys2>(non_const_sys1, non_const_sys2);
  }

}    // namespace cuda_cub
END_NS_THRUST