EnumTraits.h++

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/* ---------------------------------------------------------------------------
   commonc++ - A C++ Common Class Library
   Copyright (C) 2005-2012  Mark A Lindner

   This file is part of commonc++.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this library; if not, write to the Free
   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   ---------------------------------------------------------------------------
*/

#ifndef __ccxx_EnumTraits_hxx
#define __ccxx_EnumTraits_hxx

#include <commonc++/Common.h++>
#include <commonc++/CharTraits.h++>

#include <utility>
#include <vector>

namespace ccxx {

template<typename E> class EnumTraits
{
  public:

  static E min();

  static E max();

  static E defval();
};

template<typename T, typename E> E enum_cast(T val)
{
  if((val >= static_cast<T>(EnumTraits<E>::min()))
     && (val <= static_cast<T>(EnumTraits<E>::max())))
    return static_cast<E>(val);
  else
    return EnumTraits<E>::defval();
}

template<typename T, typename E> E enum_cast(T val, E defval)
{
  if((val >= static_cast<T>(EnumTraits<E>::min()))
     && (val <= static_cast<T>(EnumTraits<E>::max())))
    return static_cast<E>(val);
  else
    return defval;
}

template<typename E> class EnumMap
  : private std::vector<std::pair<E, const char *> >
{
  public:

  EnumMap() { }

  ~EnumMap() { }

  EnumMap& add(E value, const char *str)
  {
    this->push_back(make_pair(value, str));
    return(*this);
  }

  E valueForString(const char *str) const
  {
    for(typename Entries::const_iterator iter = this->begin();
        iter != this->end();
        ++iter)
    {
      if(CharTraits::compare(str, this->second))
        return(this->first);
    }

    return(EnumTraits<E>::defval());
  }

  const char *stringForValue(E value) const
  {
    for(typename Entries::const_iterator iter = this->begin();
        iter != this->end();
        ++iter)
    {
      if(value == iter->first)
        return(this->second);
    }

    return(NULL);
  }

  private:

  typedef std::vector<std::pair<E, const char *> > Entries;
};

}; // namespace ccxx

#endif // __ccxx_EnumTraits_hxx