multiindex.hh

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// SPDX-FileCopyrightText: Copyright © DUNE Project contributors, see file LICENSE.md in module root
// SPDX-License-Identifier: LicenseRef-GPL-2.0-only-with-DUNE-exception
#ifndef DUNE_GRID_UTILITY_MULTIINDEX_HH
#define DUNE_GRID_UTILITY_MULTIINDEX_HH
 
#include<array>
 
namespace Dune
{
 namespace FactoryUtilities
 {
  template<std::size_t dim>
  class MultiIndex : public std::array<unsigned int,dim>
  {
    // The range of each component
    std::array<unsigned int,dim> limits_;
 
  public:
    MultiIndex(const std::array<unsigned int,dim>& limits) : limits_(limits)
    {
      std::fill(this->begin(), this->end(), 0);
    }
 
    MultiIndex<dim>& operator++()
    {
      for (std::size_t i=0; i<dim; i++)
      {
        // Augment digit
        (*this)[i]++;
 
        // If there is no carry-over we can stop here
        if ((*this)[i]<limits_[i])
          break;
 
        (*this)[i] = 0;
      }
      return *this;
    }
 
    size_t cycle() const
    {
      size_t result = 1;
      for (std::size_t i=0; i<dim; i++)
        result *= limits_[i];
      return result;
    }
  };
 }
}
 
#endif