absolute.h

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/******************************************************************************
The MIT License(MIT)
 
Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com
 
Copyright(c) 2018 John Wellbelove
 
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of this software and associated documentation files(the "Software"), to deal
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#ifndef ETL_ABSOLUTE_INCLUDED
#define ETL_ABSOLUTE_INCLUDED
 
#include "type_traits.h"
#include "integral_limits.h"
 
namespace etl
{
  //***************************************************************************
  // For signed types.
  //***************************************************************************
  template <typename T>
  ETL_NODISCARD
  ETL_CONSTEXPR 
  typename etl::enable_if<etl::is_signed<T>::value, T>::type
    absolute(T value) ETL_NOEXCEPT
  {
    return (value < T(0)) ? -value : value;
  }
 
  //***************************************************************************
  // For unsigned types.
  //***************************************************************************
  template <typename T>
  ETL_NODISCARD
  ETL_CONSTEXPR
  typename etl::enable_if<etl::is_unsigned<T>::value, T>::type
    absolute(T value) ETL_NOEXCEPT
  {
    return value;
  }
 
  //***************************************************************************
  // For signed types.
  // Returns the result as the unsigned type.
  //***************************************************************************
  template <typename T>
  ETL_NODISCARD
  ETL_CONSTEXPR 
  typename etl::enable_if<etl::is_signed<T>::value, typename etl::make_unsigned<T>::type>::type
    absolute_unsigned(T value) ETL_NOEXCEPT
  {
    typedef typename etl::make_unsigned<T>::type TReturn;
 
    return (value == etl::integral_limits<T>::min) ? (etl::integral_limits<TReturn>::max / 2U) + 1U
                                                   : (value < T(0)) ? TReturn(-value) : TReturn(value);
  }
 
  //***************************************************************************
  // For unsigned types.
  // Returns the result as the unsigned type.
  //***************************************************************************
  template <typename T>
  ETL_NODISCARD
  ETL_CONSTEXPR
  typename etl::enable_if<etl::is_unsigned<T>::value, T>::type
    absolute_unsigned(T value) ETL_NOEXCEPT
  {
    return etl::absolute(value);
  }
}
 
#endif