cyclic_value.h

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/******************************************************************************
The MIT License(MIT)
 
Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com
 
Copyright(c) 2014 John Wellbelove
 
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of this software and associated documentation files(the "Software"), to deal
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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******************************************************************************/
 
#ifndef ETL_CYCLIC_VALUE_INCLUDED
#define ETL_CYCLIC_VALUE_INCLUDED

 
#include "platform.h"
#include "algorithm.h"
#include "exception.h"
#include "static_assert.h"
#include "type_traits.h"
 
#include <stddef.h>
 
namespace etl
{
  //***************************************************************************
  //***************************************************************************
  template <typename T, T First = 0, T Last = 0, bool EtlRuntimeSpecialisation = ((First == 0) && (Last == 0))>
  class cyclic_value;
 
  //***************************************************************************
  //***************************************************************************
  template <typename T, T First, T Last>
  class cyclic_value<T, First, Last, false>
  {
  public:
 
    //*************************************************************************
    //*************************************************************************
    cyclic_value()
      : value(First)
    {
    }
 
    //*************************************************************************
    //*************************************************************************
    explicit cyclic_value(T initial)
    {
      set(initial);
    }
 
    //*************************************************************************
    //*************************************************************************
    cyclic_value(const cyclic_value<T, First, Last>& other)
      : value(other.value)
    {
    }
 
    //*************************************************************************
    //*************************************************************************
    cyclic_value& operator=(const cyclic_value<T, First, Last>& other)
    {
      value = other.value;
 
      return *this;
    }
 
    //*************************************************************************
    //*************************************************************************
    void set(T value_)
    {
      value = etl::clamp(value_, First, Last);
    }
 
    //*************************************************************************
    //*************************************************************************
    void to_first()
    {
      value = First;
    }
 
    //*************************************************************************
    //*************************************************************************
    void to_last()
    {
      value = Last;
    }
 
    //*************************************************************************
    //*************************************************************************
    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) ETL_UNLIKELY
      {
        value = First;
      }
      else
      {
        ++value;
      }
 
      return *this;
    }
 
    //*************************************************************************
    //*************************************************************************
    cyclic_value operator++(int)
    {
      cyclic_value temp(*this);
 
      operator++();
 
      return temp;
    }
 
    //*************************************************************************
    //*************************************************************************
    cyclic_value& operator--()
    {
      if (value <= First) ETL_UNLIKELY
      {
        value = Last;
      }
      else
      {
        --value;
      }
 
      return *this;
    }
 
    //*************************************************************************
    //*************************************************************************
    cyclic_value operator--(int)
    {
      cyclic_value temp(*this);
 
      operator--();
 
      return temp;
    }
 
    //*************************************************************************
    //*************************************************************************
    cyclic_value& operator=(T t)
    {
      set(t);
      return *this;
    }
 
    //*************************************************************************
    //*************************************************************************
    template <const T FIRST2, const T LAST2>
    cyclic_value& operator=(const cyclic_value<T, FIRST2, LAST2>& other)
    {
      set(other.get());
      return *this;
    }
 
    //*************************************************************************
    //*************************************************************************
    T get() const
    {
      return value;
    }
 
    //*************************************************************************
    //*************************************************************************
    static ETL_CONSTEXPR T first()
    {
      return First;
    }
 
    //*************************************************************************
    //*************************************************************************
    static ETL_CONSTEXPR T last()
    {
      return Last;
    }
 
    //*************************************************************************
    //*************************************************************************
    void swap(cyclic_value<T, First, Last>& other)
    {
      using ETL_OR_STD::swap; // Allow ADL
 
      swap(value, other.value);
    }
 
    //*************************************************************************
    //*************************************************************************
    friend void swap(cyclic_value<T, First, Last>& lhs, cyclic_value<T, First, Last>& rhs)
    {
      lhs.swap(rhs);
    }
 
    //*************************************************************************
    //*************************************************************************
    friend bool operator==(const cyclic_value<T, First, Last>& lhs, const cyclic_value<T, First, Last>& rhs)
    {
      return lhs.value == rhs.value;
    }
 
    //*************************************************************************
    //*************************************************************************
    friend bool operator!=(const cyclic_value<T, First, Last>& lhs, const cyclic_value<T, First, Last>& rhs)
    {
      return !(lhs == rhs);
    }
 
  private:
 
    T value; 
  };
 
  //***************************************************************************
  //***************************************************************************
  template <typename T, T First, T Last>
  class cyclic_value<T, First, Last, true>
  {
  public:
 
    //*************************************************************************
    //*************************************************************************
    cyclic_value()
      : value(First)
      , first_value(First)
      , last_value(Last)
    {
    }
 
    //*************************************************************************
    //*************************************************************************
    cyclic_value(T first_, T last_)
      : value(first_)
      , first_value(first_)
      , last_value(last_)
    {
    }
 
    //*************************************************************************
    //*************************************************************************
    cyclic_value(T first_, T last_, T initial)
      : first_value(first_)
      , last_value(last_)
    {
      set(initial);
    }
 
    //*************************************************************************
    //*************************************************************************
    cyclic_value(const cyclic_value& other)
      : value(other.value)
      , first_value(other.first_value)
      , last_value(other.last_value)
    {
    }
 
    //*************************************************************************
    //*************************************************************************
    void set(T first_, T last_)
    {
      first_value = first_;
      last_value  = last_;
      value       = first_;
    }
 
    //*************************************************************************
    //*************************************************************************
    void set(T value_)
    {
      value = etl::clamp(value_, first_value, last_value);
    }
 
    //*************************************************************************
    //*************************************************************************
    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)
    {
      set(t);
      return *this;
    }
 
    //*************************************************************************
    //*************************************************************************
    cyclic_value& operator=(const cyclic_value& other)
    {
      value       = other.value;
      first_value = other.first_value;
      last_value  = other.last_value;
      return *this;
    }
 
    //*************************************************************************
    //*************************************************************************
    T get() const
    {
      return value;
    }
 
    //*************************************************************************
    //*************************************************************************
    T first() const
    {
      return first_value;
    }
 
    //*************************************************************************
    //*************************************************************************
    T last() const
    {
      return last_value;
    }
 
    //*************************************************************************
    //*************************************************************************
    void swap(cyclic_value<T, First, Last>& other)
    {
      using ETL_OR_STD::swap; // Allow ADL
 
      swap(first_value, other.first_value);
      swap(last_value, other.last_value);
      swap(value, other.value);
    }
 
    //*************************************************************************
    //*************************************************************************
    friend void swap(cyclic_value<T, First, Last>& lhs, cyclic_value<T, First, Last>& rhs)
    {
      lhs.swap(rhs);
    }
 
    //*************************************************************************
    //*************************************************************************
    friend bool operator==(const cyclic_value<T, First, Last>& lhs, const cyclic_value<T, First, Last>& rhs)
    {
      return (lhs.value == rhs.value) && (lhs.first_value == rhs.first_value) && (lhs.last_value == rhs.last_value);
    }
 
    //*************************************************************************
    //*************************************************************************
    friend bool operator!=(const cyclic_value<T, First, Last>& lhs, const cyclic_value<T, First, Last>& rhs)
    {
      return !(lhs == rhs);
    }
 
  private:
 
    T value;       
    T first_value; 
    T last_value;  
  };
} // namespace etl
 
#endif