/******************************************************************************
   * Copyright (c) 2011, Duane Merrill.  All rights reserved.
   * Copyright (c) 2011-2018, 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.
   *
   ******************************************************************************/
  
  /**
   * \file
   * Random-access iterator types
   */
  
  #pragma once
  
  #include <iterator>
  #include <iostream>
  
  #include "../util_namespace.cuh"
  #include "../util_macro.cuh"
  
  #if (THRUST_VERSION >= 100700)
      // This iterator is compatible with Thrust API 1.7 and newer
      #include <thrust/iterator/iterator_facade.h>
      #include <thrust/iterator/iterator_traits.h>
  #endif // THRUST_VERSION
  
  
  /// Optional outer namespace(s)
  CUB_NS_PREFIX
  
  /// CUB namespace
  namespace cub {
  
  
  /**
   * \addtogroup UtilIterator
   * @{
   */
  
  
  /**
   * \brief A discard iterator
   */
  template <typename OffsetT = ptrdiff_t>
  class DiscardOutputIterator
  {
  public:
  
      // Required iterator traits
      typedef DiscardOutputIterator   self_type;              ///< My own type
      typedef OffsetT                 difference_type;        ///< Type to express the result of subtracting one iterator from another
      typedef void                    value_type;             ///< The type of the element the iterator can point to
      typedef void                    pointer;                ///< The type of a pointer to an element the iterator can point to
      typedef void                    reference;              ///< The type of a reference to an element the iterator can point to
  
  #if (THRUST_VERSION >= 100700)
      // Use Thrust's iterator categories so we can use these iterators in Thrust 1.7 (or newer) methods
      typedef typename thrust::detail::iterator_facade_category<
          thrust::any_system_tag,
          thrust::random_access_traversal_tag,
          value_type,
          reference
        >::type iterator_category;                                        ///< The iterator category
  #else
      typedef std::random_access_iterator_tag     iterator_category;      ///< The iterator category
  #endif  // THRUST_VERSION
  
  private:
  
      OffsetT offset;
  
  #if defined(_WIN32) || !defined(_WIN64)
      // Workaround for win32 parameter-passing bug (ulonglong2 argmin DeviceReduce)
      OffsetT pad[CUB_MAX(1, (16 / sizeof(OffsetT) - 1))];
  #endif
  
  public:
  
      /// Constructor
      __host__ __device__ __forceinline__ DiscardOutputIterator(
          OffsetT offset = 0)     ///< Base offset
      :
          offset(offset)
      {}
  
      /// Postfix increment
      __host__ __device__ __forceinline__ self_type operator++(int)
      {
          self_type retval = *this;
          offset++;
          return retval;
      }
  
      /// Prefix increment
      __host__ __device__ __forceinline__ self_type operator++()
      {
          offset++;
          return *this;
      }
  
      /// Indirection
      __host__ __device__ __forceinline__ self_type& operator*()
      {
          // return self reference, which can be assigned to anything
          return *this;
      }
  
      /// Addition
      template <typename Distance>
      __host__ __device__ __forceinline__ self_type operator+(Distance n) const
      {
          self_type retval(offset + n);
          return retval;
      }
  
      /// Addition assignment
      template <typename Distance>
      __host__ __device__ __forceinline__ self_type& operator+=(Distance n)
      {
          offset += n;
          return *this;
      }
  
      /// Subtraction
      template <typename Distance>
      __host__ __device__ __forceinline__ self_type operator-(Distance n) const
      {
          self_type retval(offset - n);
          return retval;
      }
  
      /// Subtraction assignment
      template <typename Distance>
      __host__ __device__ __forceinline__ self_type& operator-=(Distance n)
      {
          offset -= n;
          return *this;
      }
  
      /// Distance
      __host__ __device__ __forceinline__ difference_type operator-(self_type other) const
      {
          return offset - other.offset;
      }
  
      /// Array subscript
      template <typename Distance>
      __host__ __device__ __forceinline__ self_type& operator[](Distance n)
      {
          // return self reference, which can be assigned to anything
          return *this;
      }
  
      /// Structure dereference
      __host__ __device__ __forceinline__ pointer operator->()
      {
          return;
      }
  
      /// Assignment to self (no-op)
      __host__ __device__ __forceinline__ void operator=(self_type const& other)
      {
          offset = other.offset;
      }
  
      /// Assignment to anything else (no-op)
      template<typename T>
      __host__ __device__ __forceinline__ void operator=(T const&)
      {}
  
      /// Cast to void* operator
      __host__ __device__ __forceinline__ operator void*() const { return NULL; }
  
      /// Equal to
      __host__ __device__ __forceinline__ bool operator==(const self_type& rhs)
      {
          return (offset == rhs.offset);
      }
  
      /// Not equal to
      __host__ __device__ __forceinline__ bool operator!=(const self_type& rhs)
      {
          return (offset != rhs.offset);
      }
  
      /// ostream operator
      friend std::ostream& operator<<(std::ostream& os, const self_type& itr)
      {
          os << "[" << itr.offset << "]";
          return os;
      }
  
  };
  
  
  /** @} */       // end group UtilIterator
  
  }               // CUB namespace
  CUB_NS_POSTFIX  // Optional outer namespace(s)