cyclic_value.h

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/******************************************************************************
The MIT License(MIT)

Embedded Template Library.

Copyright(c) 2014 jwellbelove

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#ifndef __ETL_CYCLIC_VALUE__
#define __ETL_CYCLIC_VALUE__

#include <stddef.h>


#include <algorithm>

#include "static_assert.h"
#include "exception.h"

namespace etl
{
    //***************************************************************************
    //***************************************************************************
    template <typename T, const T FIRST = T(), const T LAST = T()>
    class cyclic_value
    {
    public:

    template <typename U, const U OTHER_FIRST, const U OTHER_LAST> friend class cyclic_value;

        //*************************************************************************
        //*************************************************************************
        cyclic_value()
            : value(FIRST),
        first_value(FIRST),
              last_value(LAST)
        {
        }

        //*************************************************************************
        //*************************************************************************
        cyclic_value(const T& first_, const T& last_)
            : value(first_),
        first_value(first_),
              last_value(last_)
        {
        }

        //*************************************************************************
    //*************************************************************************
        void set(const T& first_, const T& last_)
        {
            first_value = first_;
            last_value  = last_;
            value       = first_;
        }

    //*************************************************************************
    //*************************************************************************
    void to_first()
    {
      value = first_value;
    }

    //*************************************************************************
    //*************************************************************************
    void to_last()
    {
      value = last_value;
    }

    //*************************************************************************
    //*************************************************************************
    void advance(int n)
    {
      if (n > 0)
      {
        for (int i = 0; i < n; ++i)
        {
          operator ++();
        }
      }
      else
      {
        for (int i = 0; i < -n; ++i)
        {
          operator --();
        }
      }
    }

        //*************************************************************************
        //*************************************************************************
        operator T()
        {
            return value;
        }

        //*************************************************************************
        //*************************************************************************
        operator const T() const
        {
            return value;
        }

        //*************************************************************************
        //*************************************************************************
        cyclic_value& operator ++()
        {
            if (value == last_value)
            {
                value = first_value;
            }
            else
            {
        ++value;
            }

            return *this;
        }

        //*************************************************************************
        //*************************************************************************
        cyclic_value operator ++(int)
        {
            cyclic_value temp(*this);

            operator++();

            return temp;
        }

        //*************************************************************************
        //*************************************************************************
        cyclic_value& operator --()
        {
            if (value == first_value)
            {
                value = last_value;
            }
            else
            {
                --value;
            }

            return *this;
        }

        //*************************************************************************
        //*************************************************************************
        cyclic_value operator --(int)
        {
            cyclic_value temp(*this);

            operator--();

            return temp;
        }

        //*************************************************************************
        //*************************************************************************
        cyclic_value& operator =(T t)
        {
            value = t;
            return *this;
        }   
    
    //*************************************************************************
    //*************************************************************************
    template <const T OTHER_FIRST, const T OTHER_LAST>
    cyclic_value& operator =(const cyclic_value<T, OTHER_FIRST, OTHER_LAST>& other)
    {
      value       = other.value;
      first_value = other.first_value;
      last_value  = other.last_value;
      return *this;
    }

    //*************************************************************************
        //*************************************************************************
    const T& first() const
    {
      return first_value;
    }

    //*************************************************************************
        //*************************************************************************
    const T& last() const
    {
      return last_value;
    }

    //*************************************************************************
    //*************************************************************************
    template <const T OTHER_FIRST, const T OTHER_LAST>
    void swap(cyclic_value<T, OTHER_FIRST, OTHER_LAST>& other)
    {
      std::swap(first_value, other.first_value);
      std::swap(last_value,  other.last_value);
      std::swap(value,       other.value);
    }

    private:

    T value;       
    T first_value; 
        T last_value;  
    };

  //*************************************************************************
  //*************************************************************************
  template <typename T, const T LHS_FIRST, const T LHS_LAST, const T RHS_FIRST, const T RHS_LAST>
  void swap(cyclic_value<T, LHS_FIRST, LHS_LAST>& lhs,
            cyclic_value<T, RHS_FIRST, RHS_LAST>& rhs)
  {
    lhs.swap(rhs);
  }

  //*************************************************************************
  //*************************************************************************
  template <typename T, const T LHS_FIRST, const T LHS_LAST, const T RHS_FIRST, const T RHS_LAST>
  bool operator == (const cyclic_value<T, LHS_FIRST, LHS_LAST>& lhs,
                    const cyclic_value<T, RHS_FIRST, RHS_LAST>& rhs)
  {
    return static_cast<T>(lhs) == static_cast<T>(rhs);
  }

  //*************************************************************************
  //*************************************************************************
  template <typename T, const T LHS_FIRST, const T LHS_LAST, const T RHS_FIRST, const T RHS_LAST>
  bool operator != (const cyclic_value<T, LHS_FIRST, RHS_LAST>& lhs,
                    const cyclic_value<T, RHS_FIRST, RHS_LAST>& rhs)
  {
    return !(lhs == rhs);
  }
}

#endif