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
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files(the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
copies of the Software, and to permit persons to whom the Software is
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The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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******************************************************************************/
 
#ifndef ETL_CYCLIC_VALUE_INCLUDED
#define ETL_CYCLIC_VALUE_INCLUDED
 
 
#include "platform.h"
#include "static_assert.h"
#include "exception.h"
#include "static_assert.h"
#include "type_traits.h"
#include "algorithm.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;  
  };
}
 
#endif