mapvector.h

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// The libMesh Finite Element Library.
// Copyright (C) 2002-2025 Benjamin S. Kirk, John W. Peterson, Roy H. Stogner

// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.

// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA



#ifndef LIBMESH_MAPVECTOR_H
#define LIBMESH_MAPVECTOR_H

// libMesh Includes   -------------------------------
#include "libmesh/pool_allocator.h"

// C++ Includes   -----------------------------------
#include <map>

namespace libMesh
{

template <typename Val, typename index_t=unsigned int>
class mapvector :
  public std::map<index_t, Val, std::less<index_t>,
                  FastPoolAllocator<std::pair<const index_t, Val>>>
{
public:
  typedef std::map<index_t, Val, std::less<index_t>,
                   FastPoolAllocator<std::pair<const index_t, Val>>> maptype;

  class veclike_iterator
  {
  public:
    veclike_iterator(const typename maptype::iterator & i)
      : it(i) {}

    Val & operator*() const { return it->second; }

    index_t index() const { return it->first; }

    veclike_iterator & operator++() { ++it; return *this; }

    veclike_iterator operator++(int)
    {
      veclike_iterator i = *this;
      ++(*this);
      return i;
    }

    bool operator==(const veclike_iterator & other) const
    {
      return it == other.it;
    }

    bool operator!=(const veclike_iterator & other) const
    {
      return it != other.it;
    }

  private:
    friend class mapvector;

    typename maptype::iterator it;
  };

  class const_veclike_iterator
  {
  public:
    const_veclike_iterator(const typename maptype::const_iterator & i)
      : it(i) {}

    const_veclike_iterator(const veclike_iterator & i)
      : it(i.it) {}

    const Val & operator*() const { return it->second; }

    index_t index() const { return it->first; }

    const_veclike_iterator & operator++() { ++it; return *this; }

    const_veclike_iterator operator++(int)
    {
      veclike_iterator i = *this;
      ++(*this);
      return i;
    }

    bool operator==(const const_veclike_iterator & other) const
    {
      return it == other.it;
    }

    bool operator!=(const const_veclike_iterator & other) const
    {
      return it != other.it;
    }

  private:
    friend class mapvector;

    typename maptype::const_iterator it;
  };

  class const_reverse_veclike_iterator
  {
  public:
    const_reverse_veclike_iterator(const typename maptype::const_reverse_iterator & i)
      : it(i) {}

    const_reverse_veclike_iterator(const const_veclike_iterator & i)
      : it(i.it) {}

    const_reverse_veclike_iterator(const veclike_iterator & i)
      : it(i.it) {}

    const Val & operator*() const { return it->second; }

    const_reverse_veclike_iterator & operator++() { ++it; return *this; }

    const_reverse_veclike_iterator operator++(int)
    {
      const_reverse_veclike_iterator i = *this;
      ++(*this);
      return i;
    }

    bool operator==(const const_reverse_veclike_iterator & other) const
    {
      return it == other.it;
    }

    bool operator!=(const const_reverse_veclike_iterator & other) const
    {
      return it != other.it;
    }

  private:
    friend class mapvector;

    typename maptype::const_reverse_iterator it;
  };

  veclike_iterator find (const index_t & k)
  {
    return veclike_iterator(maptype::find(k));
  }

  const_veclike_iterator find (const index_t & k) const
  {
    return const_veclike_iterator(maptype::find(k));
  }

  Val & operator[] (const index_t & k)
  {
    return maptype::operator[](k);
  }

  Val operator[] (const index_t & k) const
  {
    auto it = this->maptype::find(k);
    return it == this->end().it? Val() : it->second;
  }

  void erase(index_t i)
  {
    maptype::erase(i);
  }

  veclike_iterator erase(const veclike_iterator & pos)
  {
    return veclike_iterator(maptype::erase(pos.it));
  }

  veclike_iterator begin()
  {
    return veclike_iterator(maptype::begin());
  }

  const_veclike_iterator begin() const
  {
    return const_veclike_iterator(maptype::begin());
  }

  veclike_iterator end()
  {
    return veclike_iterator(maptype::end());
  }

  const_veclike_iterator end() const
  {
    return const_veclike_iterator(maptype::end());
  }
};

} // namespace libMesh

#endif // LIBMESH_MAPVECTOR_H