duration.h

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/******************************************************************************
The MIT License(MIT)
 
Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com
 
Copyright(c) 2023 John Wellbelove
 
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#ifndef ETL_IN_CHRONO_H
  #error DO NOT DIRECTLY INCLUDE THIS FILE. USE CHRONO.H
#endif
 
#include "../../ratio.h"
#include "../../static_assert.h"
#include "../../limits.h"
#include "../../type_traits.h"
 
#include <string.h>
 
namespace etl
{
  namespace chrono
  {
    namespace private_chrono
    {
      // Helper to find the greatest common divisor
      template <intmax_t A, intmax_t B>
      struct gcd 
      {
        static ETL_CONSTANT intmax_t value = gcd<B, A % B>::value;
      };
 
      template <intmax_t A>
      struct gcd<A, 0> 
      {
        static ETL_CONSTANT intmax_t value = A;
      };
 
      // Helper to find the least common multiple
      template <intmax_t A, intmax_t B>
      struct lcm 
      {
        static ETL_CONSTANT intmax_t value = (A / gcd<A, B>::value) * B;
      };
    }
 
    //***********************************************************************
    //***********************************************************************
    template <typename TRep>
    struct duration_values
    {
      //***********************************************************************
      ETL_NODISCARD
      static ETL_CONSTEXPR TRep zero() ETL_NOEXCEPT
      {
        return TRep(0);
      }
 
      //***********************************************************************
      ETL_NODISCARD
      static ETL_CONSTEXPR14 TRep min() ETL_NOEXCEPT
      {
        return etl::numeric_limits<TRep>::min();
      }
 
      //***********************************************************************
      ETL_NODISCARD
      static ETL_CONSTEXPR14 TRep max() ETL_NOEXCEPT
      {
        return etl::numeric_limits<TRep>::max();
      }
    };
 
    template <typename TRep, typename TPeriod>
    class duration;
 
    template <typename TToDuration, typename TRep, typename TPeriod>
    ETL_CONSTEXPR14 TToDuration duration_cast(const etl::chrono::duration<TRep, TPeriod>& d) ETL_NOEXCEPT;
 
    //***********************************************************************
    //***********************************************************************
    template <typename TRep, typename TPeriod = etl::ratio<1> >
    class duration
    {
    public:
 
      using rep    = TRep;
      using period =  typename TPeriod::type;
 
      //***********************************************************************
      ETL_CONSTEXPR duration() ETL_NOEXCEPT
        : value(0)
      {
      }
 
      //***********************************************************************
      ETL_CONSTEXPR14 duration(const etl::chrono::duration<TRep, TPeriod>& other) ETL_NOEXCEPT
        : value(other.value)
      {
      }
 
      //***********************************************************************
      template <typename TRep2>
      ETL_CONSTEXPR14 explicit duration(const TRep2& value_) ETL_NOEXCEPT
        : value(static_cast<TRep>(value_))
      {
      }
 
      //***********************************************************************
      template <typename TRep2, typename TPeriod2, typename etl::enable_if<etl::ratio_divide<TPeriod2, TPeriod>::den == 1, int>::type = 0>
      ETL_CONSTEXPR14 duration(const etl::chrono::duration<TRep2, TPeriod2>& other) ETL_NOEXCEPT
        : value(etl::chrono::duration_cast<etl::chrono::duration<TRep, TPeriod> >(other).count())
      {
        ETL_STATIC_ASSERT(!(etl::is_integral<TRep>::value && etl::is_floating_point<TRep2>::value), "Cannot convert duration from floating point to integral");
      }
 
      //***********************************************************************
      ETL_CONSTEXPR14 
      etl::chrono::duration<TRep, TPeriod> operator =(const etl::chrono::duration<TRep, TPeriod>& other) ETL_NOEXCEPT
      {
        value = other.count();
 
        return *this;
      }
 
      //***********************************************************************
      template <typename TRep2, typename TPeriod2>
      ETL_CONSTEXPR14 
      etl::chrono::duration<TRep, TPeriod> operator =(const etl::chrono::duration<TRep2, TPeriod2>& other) ETL_NOEXCEPT
      {
        value = etl::chrono::duration_cast<etl::chrono::duration<TRep, TPeriod> >(other).count();
 
        return *this;
      }
 
      //***********************************************************************
      ETL_CONSTEXPR14 TRep count() const ETL_NOEXCEPT
      {
        return value;
      }
 
      //***********************************************************************
      ETL_CONSTEXPR14 etl::common_type_t<duration> operator +() const ETL_NOEXCEPT
      {
        return etl::common_type_t<duration>(*this);
      }
 
      //***********************************************************************
      ETL_CONSTEXPR14 etl::common_type_t<duration> operator -() const ETL_NOEXCEPT
      {
        return etl::common_type_t<duration>(-value);
      }
 
      //***********************************************************************
      ETL_NODISCARD
      static ETL_CONSTEXPR14 etl::chrono::duration<TRep, TPeriod> zero()  ETL_NOEXCEPT
      {
        return etl::chrono::duration<TRep, TPeriod>(etl::chrono::duration_values<TRep>::zero());
      }
 
      //***********************************************************************
      ETL_NODISCARD
      static ETL_CONSTEXPR14 etl::chrono::duration<TRep, TPeriod> min()  ETL_NOEXCEPT
      {
        return etl::chrono::duration<TRep, TPeriod>(etl::chrono::duration_values<TRep>::min());
      }
 
      //***********************************************************************
      ETL_NODISCARD
      static ETL_CONSTEXPR14 etl::chrono::duration<TRep, TPeriod> max()  ETL_NOEXCEPT
      {
        return etl::chrono::duration<TRep, TPeriod>(etl::chrono::duration_values<TRep>::max());
      }
 
      //***********************************************************************
      ETL_NODISCARD
      ETL_CONSTEXPR14 etl::chrono::duration<TRep, TPeriod> absolute() const ETL_NOEXCEPT
      {
        return etl::chrono::duration<TRep, TPeriod>(value < 0 ? -value : value);
      }
 
      //***********************************************************************
      ETL_CONSTEXPR14 duration& operator ++() ETL_NOEXCEPT
      {
        ++value;
 
        return *this;
      }
 
      //***********************************************************************
      ETL_CONSTEXPR14 duration operator ++(int) ETL_NOEXCEPT
      {
        duration temp(*this);      
        ++value;
 
        return temp;
      }
 
      //***********************************************************************
      ETL_CONSTEXPR14 duration& operator --() ETL_NOEXCEPT
      {
        --value;
 
        return *this;
      }
 
      //***********************************************************************
      ETL_CONSTEXPR14 duration operator --(int) ETL_NOEXCEPT
      {
        duration temp(*this);
        --value;
 
        return temp;
      }
 
      //***********************************************************************
      ETL_CONSTEXPR14 duration& operator +=(const duration<TRep, TPeriod>& d) ETL_NOEXCEPT
      {
        value += d.count();
 
        return *this;
      }
 
      //***********************************************************************
      ETL_CONSTEXPR14 duration& operator -=(const duration<TRep, TPeriod>& d) ETL_NOEXCEPT
      {
        value -= d.count();
 
        return *this;
      }
 
      //***********************************************************************
      ETL_CONSTEXPR14 duration& operator *=(const TRep& r) ETL_NOEXCEPT
      {
        value *= r;
 
        return *this;
      }
 
      //***********************************************************************
      ETL_CONSTEXPR14 duration& operator /=(const TRep& r) ETL_NOEXCEPT
      {
        value /= r;
 
        return *this;
      }
 
      //***********************************************************************
      ETL_CONSTEXPR14 duration& operator %=(const TRep& r) ETL_NOEXCEPT
      {
        value %= r;
 
        return *this;
      }
 
      //***********************************************************************
      ETL_CONSTEXPR14 duration& operator %=(const duration<TRep, TPeriod>& d) ETL_NOEXCEPT
      {
        value %= d.count();
 
        return *this;
      }
 
      //***********************************************************************
      //***********************************************************************
      template <typename TRep2, typename TPeriod2>
      ETL_CONSTEXPR14 int compare(const duration<TRep2, TPeriod2>& other) const ETL_NOEXCEPT 
      {
        // Determine the common type of the two durations.
        using common_duration = typename etl::common_type<etl::chrono::duration<TRep, TPeriod>, etl::chrono::duration<TRep2, TPeriod2>>::type;
 
        common_duration lhs_converted = etl::chrono::duration_cast<common_duration>(*this);
        common_duration rhs_converted = etl::chrono::duration_cast<common_duration>(other);
 
        if (lhs_converted.count() < rhs_converted.count()) return -1;
        if (lhs_converted.count() > rhs_converted.count()) return 1;
 
        return 0;
      }
 
    private:
 
      TRep value;
    };
 
    //***********************************************************************
    //***********************************************************************
#if (ETL_USING_64BIT_TYPES)
    using nanoseconds  = etl::chrono::duration<int64_t, etl::nano>;
    using microseconds = etl::chrono::duration<int64_t, etl::micro>;
    using milliseconds = etl::chrono::duration<int64_t, etl::milli>;
    using seconds      = etl::chrono::duration<int64_t, etl::ratio<1U>>;
#else
    using nanoseconds  = etl::chrono::duration<int32_t, etl::nano>;
    using microseconds = etl::chrono::duration<int32_t, etl::micro>;
    using milliseconds = etl::chrono::duration<int32_t, etl::milli>;
    using seconds      = etl::chrono::duration<int32_t, etl::ratio<1U>>;
#endif
    using minutes = etl::chrono::duration<int32_t, etl::ratio<60U>>;
    using hours   = etl::chrono::duration<int32_t, etl::ratio<3600U>>;
    using days    = etl::chrono::duration<int32_t, etl::ratio<86400U>>;
    using weeks   = etl::chrono::duration<int32_t, etl::ratio<604800U>>;
    using months  = etl::chrono::duration<int32_t, etl::ratio<2629746U>>;
    using years   = etl::chrono::duration<int32_t, etl::ratio<31556952U>>;
 
    //***********************************************************************
    //***********************************************************************
    template <typename TToDuration, typename TRep, typename TPeriod>
    ETL_CONSTEXPR14 TToDuration duration_cast(const etl::chrono::duration<TRep, TPeriod>& d) ETL_NOEXCEPT
    {
      using from_rep    = TRep    ;
      using from_period = TPeriod ;
 
      using to_rep    = typename TToDuration::rep;
      using to_period = typename TToDuration::period;
 
      using ratio_divide_t = typename etl::ratio_divide<from_period, to_period>;
      using common_t       = typename etl::common_type<from_rep, to_rep, intmax_t>::type;
 
      common_t ct_count = static_cast<common_t>(d.count());
      common_t ct_num   = static_cast<common_t>(ratio_divide_t::type::num);
      common_t ct_den   = static_cast<common_t>(ratio_divide_t::type::den);
 
      if ETL_IF_CONSTEXPR((from_period::num == to_period::num) && (from_period::den == to_period::den))
      {
        return TToDuration(static_cast<to_rep>(d.count()));
      }
      else if ETL_IF_CONSTEXPR(ratio_divide_t::num == 1)
      {
        return TToDuration(static_cast<to_rep>(ct_count / ct_den));
      }
      else if ETL_IF_CONSTEXPR(ratio_divide_t::den == 1)
      {
        return TToDuration(static_cast<to_rep>(ct_count * ct_num));
      }
      else
      {
        return TToDuration(static_cast<to_rep>((ct_count * ct_num) / ct_den));
      }
    }
  }
 
  //*************************************************************************
  //*************************************************************************
#if ETL_USING_8BIT_TYPES
  template <typename TRep, typename TPeriod>
  struct hash<etl::chrono::duration<TRep, TPeriod> >
  {
    ETL_CONSTEXPR14 size_t operator()(const etl::chrono::duration<TRep, TPeriod>& d) const ETL_NOEXCEPT
    {
      uint8_t buffer[sizeof(TRep) + sizeof(intmax_t) + sizeof(intmax_t)];
 
      TRep value = d.count();
      intmax_t num = TPeriod::num;
      intmax_t den = TPeriod::den;
      
      memcpy(buffer, &value, sizeof(TRep));
      memcpy(buffer + sizeof(TRep), &num, sizeof(intmax_t));
      memcpy(buffer + sizeof(TRep) + sizeof(intmax_t), &den, sizeof(intmax_t));
 
      return etl::private_hash::generic_hash<size_t>(buffer, buffer + sizeof(TRep) + sizeof(intmax_t) + sizeof(intmax_t));
    }
  };
#endif
 
  //***********************************************************************
  //***********************************************************************
  template <typename TRep1, typename TPeriod1, typename TRep2, typename TPeriod2>
  struct common_type<etl::chrono::duration<TRep1, TPeriod1>, etl::chrono::duration<TRep2, TPeriod2>>
  {
  private:
 
    using value_type  = typename etl::common_type<TRep1, TRep2>::type ;
    using period_type = etl::ratio<etl::chrono::private_chrono::gcd<TPeriod1::num, TPeriod2::num>::value,
                                   etl::chrono::private_chrono::lcm<TPeriod1::den, TPeriod2::den>::value>;
 
  public:
 
    using type = etl::chrono::duration<value_type, period_type>;
  };
 
  //***********************************************************************
  //***********************************************************************
  template <typename TRep1, typename TPeriod1, typename TRep2, typename TPeriod2>
  ETL_CONSTEXPR14 bool operator ==(const etl::chrono::duration<TRep1, TPeriod1>& lhs, 
                                   const etl::chrono::duration<TRep2, TPeriod2>& rhs) ETL_NOEXCEPT
  {
    using common_t = typename etl::common_type<etl::chrono::duration<TRep1, TPeriod1>, etl::chrono::duration<TRep2, TPeriod2> >::type;
    
    common_t l = etl::chrono::duration_cast<common_t>(lhs);
    common_t r = etl::chrono::duration_cast<common_t>(rhs);
 
    return l.count() == r.count();
  }
 
  //***********************************************************************
  //***********************************************************************
  template <typename TRep1, typename TPeriod1, typename TRep2, typename TPeriod2>
  ETL_CONSTEXPR14 bool operator !=(const etl::chrono::duration<TRep1, TPeriod1>& lhs, 
                                   const etl::chrono::duration<TRep2, TPeriod2>& rhs) ETL_NOEXCEPT
  {
    return !(lhs == rhs);
  }
 
  //***********************************************************************
  //***********************************************************************
  template <typename TRep1, typename TPeriod1, typename TRep2, typename TPeriod2>
  ETL_CONSTEXPR14 bool operator <(const etl::chrono::duration<TRep1, TPeriod1>& lhs, 
                                  const etl::chrono::duration<TRep2, TPeriod2>& rhs) ETL_NOEXCEPT
  {
    using common_t = typename etl::common_type<etl::chrono::duration<TRep1, TPeriod1>, etl::chrono::duration<TRep2, TPeriod2> >::type;
 
    common_t l = etl::chrono::duration_cast<common_t>(lhs);
    common_t r = etl::chrono::duration_cast<common_t>(rhs);
 
    return l.count() < r.count();
  }
 
  //***********************************************************************
  //***********************************************************************
  template <typename TRep1, typename TPeriod1, typename TRep2, typename TPeriod2>
  ETL_CONSTEXPR14 bool operator <=(const etl::chrono::duration<TRep1, TPeriod1>& lhs, 
                                   const etl::chrono::duration<TRep2, TPeriod2>& rhs) ETL_NOEXCEPT
  {
    return !(rhs < lhs);
  }
 
  //***********************************************************************
  //***********************************************************************
  template <typename TRep1, typename TPeriod1, typename TRep2, typename TPeriod2>
  ETL_CONSTEXPR14 bool operator >(const etl::chrono::duration<TRep1, TPeriod1>& lhs, 
                                  const etl::chrono::duration<TRep2, TPeriod2>& rhs) ETL_NOEXCEPT
  {
    return rhs < lhs;
  }
 
  //***********************************************************************
  //***********************************************************************
  template <typename TRep1, typename TPeriod1, typename TRep2, typename TPeriod2>
  ETL_CONSTEXPR14 bool operator >=(const etl::chrono::duration<TRep1, TPeriod1>& lhs, 
                                   const etl::chrono::duration<TRep2, TPeriod2>& rhs) ETL_NOEXCEPT
  {
    return !(lhs < rhs);
  }
 
  //***********************************************************************
  //***********************************************************************
#if ETL_USING_CPP20
  template <typename TRep1, typename TPeriod1, typename TRep2, typename TPeriod2>
  [[nodiscard]] constexpr auto operator <=>(const etl::chrono::duration<TRep1, TPeriod1>& lhs, 
                                            const etl::chrono::duration<TRep2, TPeriod2>& rhs) ETL_NOEXCEPT
  {
    using common_t = typename etl::common_type<etl::chrono::duration<TRep1, TPeriod1>, etl::chrono::duration<TRep2, TPeriod2> >::type;
 
    common_t l = etl::chrono::duration_cast<common_t>(lhs);
    common_t r = etl::chrono::duration_cast<common_t>(rhs);
 
    return (l.count() <=> r.count());
  }
#endif
 
  //***********************************************************************
  //***********************************************************************
  template <typename TRep1, typename TPeriod1, typename TRep2, typename TPeriod2>
  ETL_CONSTEXPR14 typename etl::common_type<etl::chrono::duration<TRep1, TPeriod1>, etl::chrono::duration<TRep2, TPeriod2> >::type 
    operator +(const etl::chrono::duration<TRep1, TPeriod1>& lhs, 
               const etl::chrono::duration<TRep2, TPeriod2>& rhs) ETL_NOEXCEPT
  {
    // Determine the common type of the two durations.
    using common_duration = typename etl::common_type<etl::chrono::duration<TRep1, TPeriod1>, etl::chrono::duration<TRep2, TPeriod2>>::type;
 
    // Convert both durations to the common type.
    common_duration lhs_converted = etl::chrono::duration_cast<common_duration>(lhs);
    common_duration rhs_converted = etl::chrono::duration_cast<common_duration>(rhs);
 
    // Return the sum of the two converted durations.
    return common_duration(lhs_converted.count() + rhs_converted.count());
  }
 
  //***********************************************************************
  //***********************************************************************
  template <typename TRep1, typename TPeriod1, typename TRep2, typename TPeriod2>
  ETL_CONSTEXPR14 typename etl::common_type<etl::chrono::duration<TRep1, TPeriod1>, etl::chrono::duration<TRep2, TPeriod2> >::type 
    operator -(const etl::chrono::duration<TRep1, TPeriod1>& lhs, 
               const etl::chrono::duration<TRep2, TPeriod2>& rhs) ETL_NOEXCEPT
  {
    // Determine the common type of the two durations.
    using common_duration = typename etl::common_type<etl::chrono::duration<TRep1, TPeriod1>, etl::chrono::duration<TRep2, TPeriod2>>::type;
 
    // Convert both durations to the common type.
    common_duration lhs_converted = etl::chrono::duration_cast<common_duration>(lhs);
    common_duration rhs_converted = etl::chrono::duration_cast<common_duration>(rhs);
 
    // Return the difference of the two converted durations.
    return common_duration(lhs_converted.count() - rhs_converted.count());
  }
 
  //***********************************************************************
  //***********************************************************************
  template <typename TRep1, typename TPeriod1, typename TRep2>
  ETL_CONSTEXPR14 
  typename enable_if<!etl::is_specialization<TRep2, etl::chrono::duration>::value, etl::chrono::duration<typename etl::common_type<TRep1, TRep2>::type, TPeriod1>>::type
    operator *(const etl::chrono::duration<TRep1, TPeriod1>& lhs, 
               const TRep2& rhs) ETL_NOEXCEPT
  {
    using common_rep      = typename etl::common_type<TRep1, TRep2>::type;
    using result_duration = etl::chrono::duration<common_rep, TPeriod1>;
 
    // Multiply the count of the duration by the scalar value
    return result_duration(static_cast<common_rep>(lhs.count()) * static_cast<common_rep>(rhs));
  }
 
  //***********************************************************************
  //***********************************************************************
  template <typename TRep1, typename TRep2, typename TPeriod2>
  ETL_CONSTEXPR14 etl::chrono::duration<typename etl::common_type<TRep1, TRep2>::type, TPeriod2>
    operator *(const TRep1& lhs, 
               const etl::chrono::duration<TRep2, TPeriod2>& rhs) ETL_NOEXCEPT
  {
    using common_rep      = typename etl::common_type<TRep1, TRep2>::type;
    using result_duration = etl::chrono::duration<common_rep, TPeriod2>;
 
    // Multiply the count of the duration by the scalar value
    return result_duration(static_cast<common_rep>(rhs.count()) * static_cast<common_rep>(lhs));
  }
 
  //***********************************************************************
  //***********************************************************************
  template <typename TRep1, typename TPeriod1, typename TRep2>
  ETL_CONSTEXPR14 
  typename enable_if<!etl::is_specialization<TRep2, etl::chrono::duration>::value, etl::chrono::duration<typename etl::common_type<TRep1, TRep2>::type, TPeriod1>>::type
    operator /(const etl::chrono::duration<TRep1, TPeriod1>& lhs, 
               const TRep2& rhs) ETL_NOEXCEPT
  {
    using common_rep      = typename etl::common_type<TRep1, TRep2>::type;
    using result_duration = etl::chrono::duration<common_rep, TPeriod1>;
 
    // Divide the count of the duration by the scalar value
    return result_duration(static_cast<common_rep>(lhs.count()) / static_cast<common_rep>(rhs));
  }
 
  //***********************************************************************
  //***********************************************************************
  template <typename TRep1, typename TPeriod1, typename TRep2, typename TPeriod2>
  ETL_CONSTEXPR14 typename etl::common_type<TRep1, TRep2>::type
    operator /(const etl::chrono::duration<TRep1, TPeriod1>& lhs, 
               const etl::chrono::duration<TRep2, TPeriod2>& rhs) ETL_NOEXCEPT
  {
    // Determine the common type of the two durations.
    using common_duration = typename etl::common_type<etl::chrono::duration<TRep1, TPeriod1>, etl::chrono::duration<TRep2, TPeriod2>>::type;
 
    common_duration lhs_converted = etl::chrono::duration_cast<common_duration>(lhs);
    common_duration rhs_converted = etl::chrono::duration_cast<common_duration>(rhs);
 
    return typename etl::common_type<TRep1, TRep2>::type(lhs_converted.count() / rhs_converted.count());
  }
 
  //***********************************************************************
  //***********************************************************************
  template <typename TRep1, typename TPeriod1, typename TRep2>
  ETL_CONSTEXPR14 
  etl::chrono::duration<typename etl::common_type<TRep1, TRep2>::type, TPeriod1>
    operator %(const etl::chrono::duration<TRep1, TPeriod1>& lhs, 
               const TRep2& rhs) ETL_NOEXCEPT
  {
    using common_rep = typename etl::common_type<TRep1, TRep2>::type;
    using common_dur = etl::chrono::duration<common_rep, TPeriod1>;
 
    // Mod the count of the duration by the scalar value
    return common_dur(static_cast<common_rep>(lhs.count()) % rhs);
  }
 
  //***********************************************************************
  //***********************************************************************
  template <typename TRep1, typename TPeriod1, typename TRep2, typename TPeriod2>
  ETL_CONSTEXPR14 
  typename etl::common_type<etl::chrono::duration<TRep1, TPeriod1>, etl::chrono::duration<TRep2, TPeriod2>>::type
    operator %(const etl::chrono::duration<TRep1, TPeriod1>& lhs, 
               const etl::chrono::duration<TRep2, TPeriod2>& rhs) ETL_NOEXCEPT
  {
    // Determine the common type of the two durations.
    using common_duration = typename etl::common_type<etl::chrono::duration<TRep1, TPeriod1>, etl::chrono::duration<TRep2, TPeriod2>>::type;
 
    common_duration lhs_converted = etl::chrono::duration_cast<common_duration>(lhs);
    common_duration rhs_converted = etl::chrono::duration_cast<common_duration>(rhs);
 
    return common_duration(lhs_converted.count() % rhs_converted.count());
  }
 
  //***********************************************************************
  //***********************************************************************
  template <typename TToDuration, typename TRep, typename TPeriod>
  ETL_CONSTEXPR14
  typename etl::enable_if<etl::is_specialization<TToDuration, etl::chrono::duration>::value, TToDuration>::type
     floor(const etl::chrono::duration<TRep, TPeriod>& d) ETL_NOEXCEPT
  {
    TToDuration result = etl::chrono::duration_cast<TToDuration>(d);
 
    if (result > d)
    {
      --result;
    }
 
    return result;
  }
 
  //***********************************************************************
  //***********************************************************************
  template <typename TToDuration, typename TRep, typename TPeriod>
  ETL_CONSTEXPR14 
  typename etl::enable_if<etl::is_specialization<TToDuration, etl::chrono::duration>::value, TToDuration>::type
    ceil(const etl::chrono::duration<TRep, TPeriod>& d) ETL_NOEXCEPT
  {
    TToDuration result = etl::chrono::duration_cast<TToDuration>(d);
 
    if (result < d)
    {
      ++result;
    }
 
    return result;
  }
 
  //***********************************************************************
  //***********************************************************************
  template <typename TToDuration, typename TRep, typename TPeriod>
  ETL_CONSTEXPR14 
  typename etl::enable_if<etl::is_specialization<TToDuration, etl::chrono::duration>::value, TToDuration>::type
    round(const etl::chrono::duration<TRep, TPeriod>& d) ETL_NOEXCEPT
  {
    // Convert the input duration to the target duration type
    TToDuration lower = floor<TToDuration>(d);
    TToDuration upper = ceil<TToDuration>(lower + TToDuration(1));
 
    auto lower_diff = d - lower;
    auto upper_diff = upper - d;
 
    if ((lower_diff < upper_diff) || 
        ((lower_diff == upper_diff) &&
         etl::is_even(lower.count()))) 
    {
      return lower;
    }
    else
    {
      return upper;
    }
  }
 
  //***********************************************************************
  //***********************************************************************
  template<class TRep, class TPeriod, typename = etl::enable_if_t<etl::numeric_limits<TRep>::is_signed>>
  ETL_CONSTEXPR14 etl::chrono::duration<TRep, TPeriod> abs(etl::chrono::duration<TRep, TPeriod> d) ETL_NOEXCEPT
  {
    return d.count() >= 0 ? +d : -d;
  }
}
 
#if ETL_HAS_CHRONO_LITERALS_DURATION
namespace etl
{
  inline namespace literals
  {
    inline namespace chrono_literals
    {
      //***********************************************************************
      //***********************************************************************
#if ETL_USING_VERBOSE_CHRONO_LITERALS
      inline ETL_CONSTEXPR14 etl::chrono::hours operator ""_hours(unsigned long long h) ETL_NOEXCEPT
#else
      inline ETL_CONSTEXPR14 etl::chrono::hours operator ""_h(unsigned long long h) ETL_NOEXCEPT
#endif
      {
        return etl::chrono::hours(static_cast<etl::chrono::hours::rep>(h));
      }
 
      //***********************************************************************
      //***********************************************************************
#if ETL_USING_VERBOSE_CHRONO_LITERALS
      inline ETL_CONSTEXPR14 etl::chrono::duration<double, ratio<3600>> operator""_hours(long double h) ETL_NOEXCEPT
#else
      inline ETL_CONSTEXPR14 etl::chrono::duration<double, ratio<3600>> operator""_h(long double h) ETL_NOEXCEPT
#endif
      {
        return etl::chrono::duration<double, ratio<3600>>(h);
      }
 
      //***********************************************************************
      //***********************************************************************
#if ETL_USING_VERBOSE_CHRONO_LITERALS
      inline ETL_CONSTEXPR14 etl::chrono::minutes operator ""_minutes(unsigned long long m) ETL_NOEXCEPT
#else
      inline ETL_CONSTEXPR14 etl::chrono::minutes operator ""_min(unsigned long long m) ETL_NOEXCEPT
#endif
      {
        return etl::chrono::minutes(static_cast<etl::chrono::minutes::rep>(m));
      }
 
      //***********************************************************************
      //***********************************************************************
#if ETL_USING_VERBOSE_CHRONO_LITERALS
      inline ETL_CONSTEXPR14 etl::chrono::duration<double, ratio<60>> operator ""_minutes(long double m) ETL_NOEXCEPT
#else
      inline ETL_CONSTEXPR14 etl::chrono::duration<double, ratio<60>> operator ""_min(long double m) ETL_NOEXCEPT
#endif
      {
        return etl::chrono::duration<double, ratio<60>>(m);
      }
 
      //***********************************************************************
      //***********************************************************************
#if ETL_USING_VERBOSE_CHRONO_LITERALS
      inline ETL_CONSTEXPR14 etl::chrono::seconds operator ""_seconds(unsigned long long s) ETL_NOEXCEPT
#else
      inline ETL_CONSTEXPR14 etl::chrono::seconds operator ""_s(unsigned long long s) ETL_NOEXCEPT
#endif
      {
        return etl::chrono::seconds(static_cast<etl::chrono::seconds::rep>(s));
      }
 
      //***********************************************************************
      //***********************************************************************
#if ETL_USING_VERBOSE_CHRONO_LITERALS
      inline ETL_CONSTEXPR14 etl::chrono::duration<double> operator ""_seconds(long double s) ETL_NOEXCEPT
#else
      inline ETL_CONSTEXPR14 etl::chrono::duration<double> operator ""_s(long double s) ETL_NOEXCEPT
#endif
      {
        return etl::chrono::duration<double>(s);
      }
 
      //***********************************************************************
      //***********************************************************************
#if ETL_USING_VERBOSE_CHRONO_LITERALS
      inline ETL_CONSTEXPR14 etl::chrono::milliseconds operator ""_milliseconds(unsigned long long s) ETL_NOEXCEPT
#else
      inline ETL_CONSTEXPR14 etl::chrono::milliseconds operator ""_ms(unsigned long long s) ETL_NOEXCEPT
#endif
      {
        return etl::chrono::milliseconds(static_cast<etl::chrono::milliseconds::rep>(s));
      }
 
      //***********************************************************************
      //***********************************************************************
#if ETL_USING_VERBOSE_CHRONO_LITERALS
      inline ETL_CONSTEXPR14 etl::chrono::duration<double, milli> operator ""_milliseconds(long double s) ETL_NOEXCEPT
#else
      inline ETL_CONSTEXPR14 etl::chrono::duration<double, milli> operator ""_ms(long double s) ETL_NOEXCEPT
#endif
      {
        return etl::chrono::duration<double, milli>(s);
      }
 
      //***********************************************************************
      //***********************************************************************
#if ETL_USING_VERBOSE_CHRONO_LITERALS
      inline ETL_CONSTEXPR14 etl::chrono::microseconds operator ""_microseconds(unsigned long long s) ETL_NOEXCEPT
#else
      inline ETL_CONSTEXPR14 etl::chrono::microseconds operator ""_us(unsigned long long s) ETL_NOEXCEPT
#endif
      {
        return etl::chrono::microseconds(static_cast<etl::chrono::microseconds::rep>(s));
      }
 
      //***********************************************************************
      //***********************************************************************
#if ETL_USING_VERBOSE_CHRONO_LITERALS
      inline ETL_CONSTEXPR14 etl::chrono::duration<double, micro> operator ""_microseconds(long double s) ETL_NOEXCEPT
#else
      inline ETL_CONSTEXPR14 etl::chrono::duration<double, micro> operator ""_us(long double s) ETL_NOEXCEPT
#endif
      {
        return etl::chrono::duration<double, micro>(s);
      }
 
      //***********************************************************************
      //***********************************************************************
#if ETL_USING_VERBOSE_CHRONO_LITERALS
      inline ETL_CONSTEXPR14 etl::chrono::nanoseconds operator ""_nanoseconds(unsigned long long s) ETL_NOEXCEPT
#else
      inline ETL_CONSTEXPR14 etl::chrono::nanoseconds operator ""_ns(unsigned long long s) ETL_NOEXCEPT
#endif
      {
        return etl::chrono::nanoseconds(static_cast<etl::chrono::nanoseconds::rep>(s));
      }
 
      //***********************************************************************
      //***********************************************************************
#if ETL_USING_VERBOSE_CHRONO_LITERALS
      inline ETL_CONSTEXPR14 etl::chrono::duration<double, nano> operator ""_nanoseconds(long double s) ETL_NOEXCEPT
#else
      inline ETL_CONSTEXPR14 etl::chrono::duration<double, nano> operator ""_ns(long double s) ETL_NOEXCEPT
#endif
      {
        return etl::chrono::duration<double, nano>(s);
      }
    }
  }
}
#endif