source: trunk/yat/utility/Index.h @ 1797

#ifndef _theplu_yat_utility_index_ 
#define _theplu_yat_utility_index_ 

// $Id: Index.h 1797 2009-02-12 18:07:10Z peter $

/*
  Copyright (C) 2008 Jari Häkkinen, Peter Johansson
  Copyright (C) 2009 Peter Johansson

  This file is part of the yat library, http://dev.thep.lu.se/yat

  The yat library is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License as
  published by the Free Software Foundation; either version 3 of the
  License, or (at your option) any later version.

  The yat 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
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with yat. If not, see <http://www.gnu.org/licenses/>.
*/

#include "SmartPtr.h"

#include <vector>

namespace theplu {
namespace yat {
namespace utility {

  /**
     \brief Class for storing indices of, e.g., a MatrixLookup.

     This class is basically a wrapper around std::vector<size_t>. The
     major differences are that the class is constant and copying is
     performed in constant time (shallow copy).
   */
  class Index
  {
  public:
    /**
       Read only iterator

       \since New in yat 0.5
     */
    typedef std::vector<size_t>::const_iterator const_iterator;

    /**
       Creates an empty Index
     */
    Index(void);

    /**
       Created Index will satisfy a[i] = i.
       \param n size of created Index
    */
    explicit Index(size_t n);

    /**
       Constructed Index c will satisfy c[i]=a[b[i]]
     */
    Index(const Index& a, const Index& b);

    /**
       \brief Constructor
     */
    explicit Index(const SmartPtr<const std::vector<size_t> >& vec);

    /**
       \brief Constructor

       vec is copied
     */
    explicit Index(const std::vector<size_t>& vec);

    /**
       \return iterator pointing to first element of Index

       \since New in yat 0.5
     */
    const_iterator begin(void) const;

    /**
       \return iterator pointing to element one passed last Index

       \since New in yat 0.5
     */
    const_iterator end(void) const;

    /**
       \brief access operator
    */
    const size_t& operator[](size_t) const;

    /**
       \brief number of elements
    */
    size_t size(void) const;

    /**
       \return underlying vector
    */
    const std::vector<size_t>& vector(void) const;

  private:
    // using compiler generated copy
    // Index(const Index&);
    // const Index& operator=(const Index&);

    SmartPtr<const std::vector<size_t> > index_;
  };

}}} // of namespace utility, yat, and theplu

#endif