smallest.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
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to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
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The above copyright notice and this permission notice shall be included in all
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#if 0
#error THIS HEADER IS A GENERATOR. DO NOT INCLUDE.
#endif
 
//***************************************************************************
// THIS FILE HAS BEEN AUTO GENERATED. DO NOT EDIT THIS FILE.
//***************************************************************************
 
//***************************************************************************
// To generate to header file, run this at the command line.
// Note: You will need Python and COG installed.
//
// cog -d -e -osmallest.h -DNTypes=<n> smallest_generator.h
// Where <n> is the number of types to support.
//
// e.g.
// To generate handlers for up to 16 types...
// cog -d -e -osmallest.h -DNTypes=16 smallest_generator.h
//
// See generate.bat
//***************************************************************************
 
#ifndef ETL_SMALLEST_INCLUDED
#define ETL_SMALLEST_INCLUDED
 
#include "platform.h"
#include "integral_limits.h"
 
#include <stdint.h>
 
 
namespace etl
{
#if ETL_USING_CPP11 && !defined(ETL_SMALLEST_TYPE_FORCE_CPP03_IMPLEMENTATION)
  //***************************************************************************
  //***************************************************************************
  template <typename T1, typename... TRest>
  class smallest_type
  {
  private:
 
    // Define 'smallest_other' as 'smallest_type' with all but the first parameter.
    using smallest_other = typename smallest_type<TRest...>::type;
 
  public:
 
    // Set 'type' to be the smallest of the first parameter and any of the others.
    // This is recursive.
    using type = typename etl::conditional<(etl::size_of<T1>::value < etl::size_of<smallest_other>::value), // Boolean
                                            T1,                                                             // TrueType
                                            smallest_other>                                                 // FalseType
                                            ::type;                                                         // The smallest type of the two.
 
    // The size of the smallest type.
    enum
    {
      size = etl::size_of<type>::value
    };
  };
 
  //***************************************************************************
  // Specialisation for one template parameter.
  //***************************************************************************
  template <typename T1>
  class smallest_type<T1>
  {
  public:
 
    using type = T1;
 
    enum
    {
      size = etl::size_of<type>::value
    };
  };
 
#if ETL_USING_CPP11
  template <typename... T>
  using smallest_type_t = typename smallest_type<T...>::type;
#endif
 
#if ETL_USING_CPP17
  template <typename... T>
  constexpr size_t smallest_type_v = smallest_type<T...>::size;
#endif
 
#else
  //***************************************************************************
  //***************************************************************************
  template <typename T1, typename T2 = void, typename T3 = void, typename T4 = void, 
            typename T5 = void, typename T6 = void, typename T7 = void, typename T8 = void, 
            typename T9 = void, typename T10 = void, typename T11 = void, typename T12 = void, 
            typename T13 = void, typename T14 = void, typename T15 = void, typename T16 = void>
  struct smallest_type
  {
  private:
 
    // Declaration.
    template <bool Boolean, typename TrueType, typename FalseType>
    struct choose_type;
 
    // Specialisation for 'true'.
    // Defines 'type' as 'TrueType'.
    template <typename TrueType, typename FalseType>
    struct choose_type<true, TrueType, FalseType>
    {
      typedef TrueType type;
    };
 
    // Specialisation for 'false'. 
    // Defines 'type' as 'FalseType'.
    template <typename TrueType, typename FalseType>
    struct choose_type<false, TrueType, FalseType>
    {
      typedef FalseType type;
    };
 
  public:
 
    // Define 'smallest_other' as 'smallest_type' with all but the first parameter. 
    typedef typename smallest_type<T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>::type smallest_other;
 
    // Set 'type' to be the smallest of the first parameter and any of the others.
    // This is recursive.
    typedef typename choose_type<(sizeof(T1) < sizeof(smallest_other)), // Boolean
                                  T1,                                   // TrueType
                                  smallest_other>                       // FalseType
                                  ::type type;                          // The smallest type of the two.
 
    // The size of the smallest type.
    enum
    {
      size = sizeof(type)
    };
  };
 
  //***************************************************************************
  // Specialisation for one template parameter.
  //***************************************************************************
  template <typename T1>
  struct smallest_type<T1,   void, void, void, void, void, void, void, 
                       void, void, void, void, void, void, void, void>
  {
    typedef T1 type;
 
    enum
    {
      size = sizeof(type)
    };
  };
#endif
 
  namespace private_smallest
  {
    //*************************************************************************
    // Determine the type to hold the number of bits based on the index.
    //*************************************************************************
    template <int index>
    struct best_fit_uint_type;
 
    //*************************************************************************
    // Less than or equal to 8 bits.
    //*************************************************************************
    template <>
    struct best_fit_uint_type<0>
    {
      typedef uint_least8_t type;
    };
 
    //*************************************************************************
    // 9 to 16 bits.
    //*************************************************************************
    template <>
    struct best_fit_uint_type<1>
    {
      typedef uint_least16_t type;
    };
 
    //*************************************************************************
    // 17 to 31 bits.
    //*************************************************************************
    template <>
    struct best_fit_uint_type<2>
    {
      typedef uint_least32_t type;
    };
 
#if ETL_USING_64BIT_TYPES
    //*************************************************************************
    // Greater than 32 bits.
    //*************************************************************************
    template <>
    struct best_fit_uint_type<3>
    {
      typedef uint_least64_t type;
    };
#endif
 
    //*************************************************************************
    // Determine the type to hold the number of bits based on the index.
    //*************************************************************************
    template <int index>
    struct best_fit_int_type;
 
    //*************************************************************************
    // Less than or equal to 8 bits.
    //*************************************************************************
    template <>
    struct best_fit_int_type<0>
    {
      typedef int_least8_t type;
    };
 
    //*************************************************************************
    // 9 to 16 bits.
    //*************************************************************************
    template <>
    struct best_fit_int_type<1>
    {
      typedef int_least16_t type;
    };
 
    //*************************************************************************
    // 17 to 31 bits.
    //*************************************************************************
    template <>
    struct best_fit_int_type<2>
    {
      typedef int_least32_t type;
    };
 
#if ETL_USING_64BIT_TYPES
    //*************************************************************************
    // Greater than 32 bits.
    //*************************************************************************
    template <>
    struct best_fit_int_type<3>
    {
      typedef int_least64_t type;
    };
#endif
  }
 
  //***************************************************************************
  //***************************************************************************
  template <size_t NBITS>
  struct smallest_uint_for_bits
  {
  private:
 
    // Determines the index of the best unsigned type for the required number of bits.
    static ETL_CONSTANT int TYPE_INDEX = ((NBITS >  8) ? 1 : 0) +
                                         ((NBITS > 16) ? 1 : 0) +
                                         ((NBITS > 32) ? 1 : 0);
 
  public:
 
    typedef typename private_smallest::best_fit_uint_type<TYPE_INDEX>::type type;
  };
 
  template <size_t NBITS>
  ETL_CONSTANT int smallest_uint_for_bits<NBITS>::TYPE_INDEX;
 
#if ETL_USING_CPP11
  template <size_t NBITS>
  using smallest_uint_for_bits_t = typename smallest_uint_for_bits<NBITS>::type;
#endif
 
  //***************************************************************************
  //***************************************************************************
  template <size_t NBITS>
  struct smallest_int_for_bits
  {
  private:
 
    // Determines the index of the best unsigned type for the required number of bits.
    static ETL_CONSTANT int TYPE_INDEX = ((NBITS >  8) ? 1 : 0) +
                                         ((NBITS > 16) ? 1 : 0) +
                                         ((NBITS > 32) ? 1 : 0);
 
  public:
 
    typedef typename private_smallest::best_fit_int_type<TYPE_INDEX>::type type;
  };
 
  template <size_t NBITS>
  ETL_CONSTANT int smallest_int_for_bits<NBITS>::TYPE_INDEX;
 
#if ETL_USING_CPP11
  template <size_t NBITS>
  using smallest_int_for_bits_t = typename smallest_int_for_bits<NBITS>::type;
#endif
 
  //***************************************************************************
  //***************************************************************************
  template <uintmax_t VALUE>
  struct smallest_uint_for_value
  {
  private:
 
    // Determines the index of the best unsigned type for the required value.
    static ETL_CONSTANT int TYPE_INDEX = ((VALUE > UINT_LEAST8_MAX) ? 1 : 0) +
      ((VALUE > UINT16_MAX) ? 1 : 0) +
      ((VALUE > UINT32_MAX) ? 1 : 0);
 
  public:
 
    typedef typename private_smallest::best_fit_uint_type<TYPE_INDEX>::type type;
  };
 
  template <uintmax_t VALUE>
  ETL_CONSTANT int smallest_uint_for_value<VALUE>::TYPE_INDEX;
 
#if ETL_USING_CPP11
  template <uintmax_t VALUE>
  using smallest_uint_for_value_t = typename smallest_uint_for_value<VALUE>::type;
#endif
 
  //***************************************************************************
  //***************************************************************************
  template <intmax_t VALUE>
  struct smallest_int_for_value
  {
  private:
 
    // Determines the index of the best signed type for the required value.
    static ETL_CONSTANT int TYPE_INDEX = (((VALUE > intmax_t(INT_LEAST8_MAX)) || (VALUE < intmax_t(INT_LEAST8_MIN))) ? 1 : 0) +
      (((VALUE > intmax_t(INT16_MAX)) || (VALUE < intmax_t(INT16_MIN))) ? 1 : 0) +
      (((VALUE > intmax_t(INT32_MAX)) || (VALUE < intmax_t(INT32_MIN))) ? 1 : 0);
 
  public:
 
    typedef typename private_smallest::best_fit_int_type<TYPE_INDEX>::type type;
  };
 
  template <intmax_t VALUE>
  ETL_CONSTANT int smallest_int_for_value<VALUE>::TYPE_INDEX;
 
#if ETL_USING_CPP11
  template <intmax_t VALUE>
  using smallest_int_for_value_t = typename smallest_int_for_value<VALUE>::type;
#endif
}
 
#endif