text: /***************************************************************************************************
   * Copyright (c) 2017-2019, 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 TOR (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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   **************************************************************************************************/
  #pragma once
  
  //#include <stdexcept>
  #include "cutlass/cutlass.h"
  //#include "tools/util/reference/device/kernel/tensor_foreach.h"
  
  namespace cutlass {
  namespace layout {
  namespace thread {
  
  ///////////////////////////////////////////////////////////////////////////////////////////////////
  
  /// Defines several helpers
  namespace detail {
  
  /// Helper to perform for-each operation
  template <typename Func, int Rank, int RankRemaining>
  struct TensorForEachHelper {
    /// Index of the active rank
    static int const kActiveRank = Rank - RankRemaining - 1;
  
    /// Constructor for general rank
    CUTLASS_DEVICE TensorForEachHelper(Func &func, Coord<Rank> const &size, Coord<Rank> &coord) {
      for (int i = 0; i < size.at(kActiveRank); ++i) {
        coord[kActiveRank] = i;
        TensorForEachHelper<Func, Rank, RankRemaining - 1>(func, size, coord);
      }
    }
  };
  
  /// Helper to perform for-each operation
  template <typename Func, int Rank>
  struct TensorForEachHelper<Func, Rank, 0> {
    /// Index of the active rank
    static int const kActiveRank = Rank - 1;
  
    /// Constructor for fastest chaning rank
    CUTLASS_DEVICE TensorForEachHelper(Func &func, Coord<Rank> const &size, Coord<Rank> &coord) {
      for (int i = 0; i < size.at(kActiveRank); ++i) {
        coord[kActiveRank] = i;
        func(coord);
      }
    }
  };
  
  }  // namespace detail
  
  ///////////////////////////////////////////////////////////////////////////////////////////////////
  
  /// Iterates over the index space of a tensor
  template <typename Func, int Rank, typename Params>
  struct TensorForEach {
    /// Constructor performs the operation.
    CUTLASS_DEVICE TensorForEach(Coord<Rank> size, Params params = Params()) {
      Func func(params);
      Coord<Rank> coord;
  
      detail::TensorForEachHelper<Func, Rank, Rank - 1>(func, size, coord);
    }
  };
  
  ///////////////////////////////////////////////////////////////////////////////////////////////////
  
  }  // namespace thread
  }  // namespace layout
  }  // namespace cutlass
  