text: /*
    EEPROM.h - EEPROM library
    Original Copyright (c) 2006 David A. Mellis.  All right reserved.
    New version by Christopher Andrews 2015.
  
    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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
  
  #ifndef EEPROM_h
  #define EEPROM_h
  
  #include "Arduino.h"
  
  /***
      EERef class.
      
      This object references an EEPROM cell.
      Its purpose is to mimic a typical byte of RAM, however its storage is the EEPROM.
      This class has an overhead of two bytes, similar to storing a pointer to an EEPROM cell.
  ***/
  
  struct EERef{
  
      EERef( const int index )
          : index( index )                 {}
      
      //Access/read members.
      uint8_t operator*() const            { return eeprom_read_byte( /*(uint8_t*)*/ index ); }
      operator const uint8_t() const       { return **this; }
      
      //Assignment/write members.
      EERef &operator=( const EERef &ref ) { return *this = *ref; }
      EERef &operator=( uint8_t in )       { return eeprom_write_byte( /*(uint8_t*)*/ index, in ), *this;  }
      EERef &operator +=( uint8_t in )     { return *this = **this + in; }
      EERef &operator -=( uint8_t in )     { return *this = **this - in; }
      EERef &operator *=( uint8_t in )     { return *this = **this * in; }
      EERef &operator /=( uint8_t in )     { return *this = **this / in; }
      EERef &operator ^=( uint8_t in )     { return *this = **this ^ in; }
      EERef &operator %=( uint8_t in )     { return *this = **this % in; }
      EERef &operator &=( uint8_t in )     { return *this = **this & in; }
      EERef &operator |=( uint8_t in )     { return *this = **this | in; }
      EERef &operator <<=( uint8_t in )    { return *this = **this << in; }
      EERef &operator >>=( uint8_t in )    { return *this = **this >> in; }
      
      EERef &update( uint8_t in )          { return  in != *this ? *this = in : *this; }
      
      /** Prefix increment/decrement **/
      EERef& operator++()                  { return *this += 1; }
      EERef& operator--()                  { return *this -= 1; }
      
      /** Postfix increment/decrement **/
      uint8_t operator++ (int){ 
          uint8_t ret = **this;
          return ++(*this), ret;
      }
  
      uint8_t operator-- (int){ 
          uint8_t ret = **this;
          return --(*this), ret;
      }
      
      int index; //Index of current EEPROM cell.
  };
  
  /***
      EEPtr class.
      
      This object is a bidirectional pointer to EEPROM cells represented by EERef objects.
      Just like a normal pointer type, this can be dereferenced and repositioned using 
      increment/decrement operators.
  ***/
  
  struct EEPtr{
  
      EEPtr( const int index )
          : index( index )                {}
          
      operator const int() const          { return index; }
      EEPtr &operator=( int in )          { return index = in, *this; }
      
      //Iterator functionality.
      bool operator!=( const EEPtr &ptr ) { return index != ptr.index; }
      EERef operator*()                   { return index; }
      
      /** Prefix & Postfix increment/decrement **/
      EEPtr& operator++()                 { return ++index, *this; }
      EEPtr& operator--()                 { return --index, *this; }
      EEPtr operator++ (int)              { return index++; }
      EEPtr operator-- (int)              { return index--; }
  
      int index; //Index of current EEPROM cell.
  };
  
  /***
      EEPROMClass class.
      
      This object represents the entire EEPROM space.
      It wraps the functionality of EEPtr and EERef into a basic interface.
      This class is also 100% backwards compatible with earlier Arduino core releases.
  ***/
  
  struct EEPROMClass{
  
      //Basic user access methods.
      EERef operator[]( const int idx )    { return idx; }
      uint8_t read( int idx )              { return EERef( idx ); }
      void write( int idx, uint8_t val )   { (EERef( idx )) = val; }
      void update( int idx, uint8_t val )  { EERef( idx ).update( val ); }
      
      //STL and C++11 iteration capability.
      EEPtr begin()                        { return 0x00; }
      EEPtr end()                          { return length(); } //Standards requires this to be the item after the last valid entry. The returned pointer is invalid.
      uint16_t length()                    { return E2END; }
      
      //Functionality to 'get' and 'put' objects to and from EEPROM.
      template< typename T > T &get( int idx, T &t ){
          EEPtr e = idx;
          uint8_t *ptr = (uint8_t*) &t;
          for( int count = sizeof(T) ; count ; --count, ++e )  *ptr++ = *e;
          return t;
      }
      
      template< typename T > const T &put( int idx, const T &t ){
          EEPtr e = idx;
          const uint8_t *ptr = (const uint8_t*) &t;
          for( int count = sizeof(T) ; count ; --count, ++e )  (*e).update( *ptr++ );
          return t;
      }
  };
  
  static EEPROMClass EEPROM;
  #endif
  