thrust/random/xor_combine_engine.h

File members: thrust/random/xor_combine_engine.h

/*
 *  Copyright 2008-2013 NVIDIA Corporation
 *
 *  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.
 */

#pragma once

#include <thrust/detail/config.h>

#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
#  pragma GCC system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
#  pragma clang system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
#  pragma system_header
#endif // no system header

#include <thrust/detail/type_traits.h>
#include <thrust/random/detail/random_core_access.h>
#include <thrust/random/detail/xor_combine_engine_max.h>

#include <cstddef> // for size_t
#include <iostream>

THRUST_NAMESPACE_BEGIN

namespace random
{

template <typename Engine1, size_t s1, typename Engine2, size_t s2 = 0u>
class xor_combine_engine
{
public:
  // types

  using base1_type = Engine1;

  using base2_type = Engine2;

  using result_type = typename thrust::detail::eval_if<
    (sizeof(typename base2_type::result_type) > sizeof(typename base1_type::result_type)),
    thrust::detail::identity_<typename base2_type::result_type>,
    thrust::detail::identity_<typename base1_type::result_type>>::type;

  static const size_t shift1 = s1;

  static const size_t shift2 = s2;

  static const result_type min = 0;

  static const result_type max = detail::xor_combine_engine_max<Engine1, s1, Engine2, s2, result_type>::value;

  // constructors and seeding functions

  _CCCL_HOST_DEVICE xor_combine_engine();

  _CCCL_HOST_DEVICE xor_combine_engine(const base1_type& urng1, const base2_type& urng2);

  _CCCL_HOST_DEVICE xor_combine_engine(result_type s);

  _CCCL_HOST_DEVICE void seed();

  _CCCL_HOST_DEVICE void seed(result_type s);

  // generating functions

  _CCCL_HOST_DEVICE result_type operator()(void);

  _CCCL_HOST_DEVICE void discard(unsigned long long z);

  // property functions

  _CCCL_HOST_DEVICE const base1_type& base1() const;

  _CCCL_HOST_DEVICE const base2_type& base2() const;

private:
  base1_type m_b1;
  base2_type m_b2;

  friend struct thrust::random::detail::random_core_access;

  _CCCL_HOST_DEVICE bool equal(const xor_combine_engine& rhs) const;

  template <typename CharT, typename Traits>
  std::basic_istream<CharT, Traits>& stream_in(std::basic_istream<CharT, Traits>& is);

  template <typename CharT, typename Traits>
  std::basic_ostream<CharT, Traits>& stream_out(std::basic_ostream<CharT, Traits>& os) const;

}; // end xor_combine_engine

template <typename Engine1_, size_t s1_, typename Engine2_, size_t s2_>
_CCCL_HOST_DEVICE bool operator==(const xor_combine_engine<Engine1_, s1_, Engine2_, s2_>& lhs,
                                  const xor_combine_engine<Engine1_, s1_, Engine2_, s2_>& rhs);

template <typename Engine1_, size_t s1_, typename Engine2_, size_t s2_>
_CCCL_HOST_DEVICE bool operator!=(const xor_combine_engine<Engine1_, s1_, Engine2_, s2_>& lhs,
                                  const xor_combine_engine<Engine1_, s1_, Engine2_, s2_>& rhs);

template <typename Engine1_, size_t s1_, typename Engine2_, size_t s2_, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>&
operator<<(std::basic_ostream<CharT, Traits>& os, const xor_combine_engine<Engine1_, s1_, Engine2_, s2_>& e);

template <typename Engine1_, size_t s1_, typename Engine2_, size_t s2_, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>&
operator>>(std::basic_istream<CharT, Traits>& is, xor_combine_engine<Engine1_, s1_, Engine2_, s2_>& e);

} // namespace random

// import names into thrust::
using random::xor_combine_engine;

THRUST_NAMESPACE_END

#include <thrust/random/detail/xor_combine_engine.inl>