type_traits.h

///\file

/******************************************************************************
The MIT License(MIT)

Embedded Template Library.
https://github.com/ETLCPP/etl

Copyright(c) 2014 jwellbelove

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******************************************************************************/

#ifndef __ETL_TYPE_TRAITS__
#define __ETL_TYPE_TRAITS__

#include <stddef.h>

#include "nullptr.h"

///\defgroup type_traits type_traits
/// A set of type traits definitions for compilers that do not support the standard header.
/// \ingroup utilities

namespace etl
{
  /// integral_constant
  ///\ingroup type_traits
  template <typename T, const T VALUE>
  struct integral_constant
  {
	  static const T value = VALUE;

	  typedef T value_type;
    typedef integral_constant<T, VALUE> type;

	  operator value_type() const
	  {
		   return value;
	  }
  };

  /// integral_constant specialisations
  ///\ingroup type_traits
  typedef integral_constant<bool, false> false_type;
  typedef integral_constant<bool, true>  true_type;

  /// remove_reference
  ///\ingroup type_traits
  template <typename T> struct remove_reference { typedef T type; };
  template <typename T> struct remove_reference<T&> { typedef T type; };

  /// add_reference
  ///\ingroup type_traits
  template <typename T> struct add_reference { typedef T& type; };
  template <typename T> struct add_reference<T&> { typedef T& type; };

  /// remove_pointer
  ///\ingroup type_traits
  template <typename T> struct remove_pointer { typedef T type; };
  template <typename T> struct remove_pointer<T*> { typedef T type; };

  /// add_pointer
  ///\ingroup type_traits
  template <typename T> struct add_pointer { typedef typename remove_reference<T>::type* type; };

  /// is_const
  ///\ingroup type_traits
  template <typename T> struct is_const : false_type {};
  template <typename T> struct is_const<const T> : true_type {};
  template <typename T> struct is_const<const volatile T> : true_type {};

  /// remove_const
  ///\ingroup type_traits
  template <typename T> struct remove_const { typedef T type; };
  template <typename T> struct remove_const<const T> { typedef T type; };

  /// add_const
  ///\ingroup type_traits
  template <typename T> struct add_const { typedef const T type; };
  template <typename T> struct add_const<const T> { typedef const T type; };

  /// is_volatile
  ///\ingroup type_traits
  template <typename T> struct is_volatile : false_type {};
  template <typename T> struct is_volatile<volatile T> : true_type {};
  template <typename T> struct is_volatile<const volatile T> : true_type {};

  /// remove_volatile
  ///\ingroup type_traits
  template <typename T> struct remove_volatile { typedef T type; };
  template <typename T> struct remove_volatile<volatile T> { typedef T type; };

  /// add_volatile
  ///\ingroup type_traits
  template <typename T> struct add_volatile { typedef volatile T type; };
  template <typename T> struct add_volatile<volatile T> { typedef volatile T type; };

  /// remove_cv
  ///\ingroup type_traits
  template <typename T> struct remove_cv
  {
    typedef typename remove_volatile<typename remove_const<T>::type>::type type;
  };

  /// add_cv
  ///\ingroup type_traits
  template <typename T> struct add_cv
  {
    typedef typename add_volatile<typename add_const<T>::type>::type type;
  };

  /// is_integral
  ///\ingroup type_traits
  template <typename T> struct is_integral : false_type {};
  template <> struct is_integral<bool> : true_type {};
  template <> struct is_integral<char> : true_type {};
  template <> struct is_integral<unsigned char> : true_type {};
  template <> struct is_integral<signed char> : true_type {};
  template <> struct is_integral<wchar_t> : true_type {};
  template <> struct is_integral<short> : true_type {};
  template <> struct is_integral<unsigned short> : true_type {};
  template <> struct is_integral<int> : true_type {};
  template <> struct is_integral<unsigned int> : true_type {};
  template <> struct is_integral<long> : true_type {};
  template <> struct is_integral<unsigned long> : true_type {};
  template <> struct is_integral<long long> : true_type {};
  template <> struct is_integral<unsigned long long> : true_type {};
  template <typename T> struct is_integral<const T> : is_integral<T> {};
  template <typename T> struct is_integral<volatile T> : is_integral<T> {};
  template <typename T> struct is_integral<const volatile T> : is_integral<T> {};

  /// is_signed
  ///\ingroup type_traits
  template <typename T> struct is_signed : false_type {};
  template <> struct is_signed<char> : true_type {};
#ifdef PLATFORM_LINUX
  template <> struct is_signed<wchar_t> : true_type {};
#endif
  template <> struct is_signed<signed char> : true_type {};
  template <> struct is_signed<short> : true_type {};
  template <> struct is_signed<int> : true_type {};
  template <> struct is_signed<long> : true_type {};
  template <> struct is_signed<long long> : true_type {};
  template <> struct is_signed<float> : true_type{};
  template <> struct is_signed<double> : true_type{};
  template <> struct is_signed<long double> : true_type{};
  template <typename T> struct is_signed<const T> : is_signed<T> {};
  template <typename T> struct is_signed<volatile T> : is_signed<T> {};
  template <typename T> struct is_signed<const volatile T> : is_signed<T> {};

  /// is_unsigned
  ///\ingroup type_traits
  template <typename T> struct is_unsigned : false_type {};
  template <> struct is_unsigned<bool> : true_type {};
  template <> struct is_unsigned<unsigned char> : true_type {};
#ifndef PLATFORM_LINUX
  template <> struct is_unsigned<wchar_t> : true_type {};
#endif
  template <> struct is_unsigned<unsigned short> : true_type {};
  template <> struct is_unsigned<unsigned int> : true_type {};
  template <> struct is_unsigned<unsigned long> : true_type {};
  template <> struct is_unsigned<unsigned long long> : true_type {};
  template <typename T> struct is_unsigned<const T> : is_unsigned<T> {};
  template <typename T> struct is_unsigned<volatile T> : is_unsigned<T> {};
  template <typename T> struct is_unsigned<const volatile T> : is_unsigned<T> {};

  /// is_floating_point
  ///\ingroup type_traits
  template <typename T> struct is_floating_point : false_type {};
  template <> struct is_floating_point<float> : true_type {};
  template <> struct is_floating_point<double> : true_type {};
  template <> struct is_floating_point<long double> : true_type {};
  template <typename T> struct is_floating_point<const T> : is_floating_point<T> {};
  template <typename T> struct is_floating_point<volatile T> : is_floating_point<T> {};
  template <typename T> struct is_floating_point<const volatile T> : is_floating_point<T> {};

  /// is_same
  ///\ingroup type_traits
  template <typename T1, typename T2> struct is_same : public false_type {};
  template <typename T> struct is_same<T, T> : public true_type {};

  /// is_void
  ///\ingroup type_traits
  template<typename T> struct is_void : false_type {};
  template<> struct is_void<void> : true_type {};

  /// is_arithmetic
  ///\ingroup type_traits
  template<typename T> struct is_arithmetic : integral_constant<bool, is_integral<T>::value || is_floating_point<T>::value> {};

  /// is_fundamental
  ///\ingroup type_traits
  template <typename T> struct is_fundamental : integral_constant<bool, is_arithmetic<T>::value ||
                                                                        is_void<T>::value  ||
                                                                        is_same<nullptr_t,
                                                                  typename remove_cv<T>::type>::value> {};

  /// is_compound
  ///\ingroup type_traits
  template <typename T> struct is_compound : integral_constant<bool, !is_fundamental<T>::value> {};

  /// is_array
  ///\ingroup type_traits
  template <typename T> struct is_array : false_type {};
  template <typename T> struct is_array<T[]> : true_type {};
  template <typename T, size_t N> struct is_array<T[N]> : true_type {};

  /// is_pointer
  ///\ingroup type_traits
  template <typename T> struct is_pointer : false_type {};
  template <typename T> struct is_pointer<T*> : true_type {};

  /// is_reference
  ///\ingroup type_traits
  template <typename T> struct is_reference : false_type {};
  template <typename T> struct is_reference<T&> : true_type {};

  /// make_signed
  ///\ingroup type_traits
  template <typename T> struct make_signed { typedef  T type; };
  template <> struct make_signed<char> { typedef  signed char type; };
  template <> struct make_signed<unsigned char> { typedef  signed char type; };
#ifdef COMPILER_MICROSOFT
  template <> struct make_signed<wchar_t> { typedef  short type; };
#endif
  template <> struct make_signed<unsigned short> { typedef  short type; };
  template <> struct make_signed<unsigned int> { typedef int type; };
  template <> struct make_signed<unsigned long> { typedef  long type; };
  template <> struct make_signed<unsigned long long> { typedef long long type; };
  template <typename T> struct make_signed<const T> : add_const<typename make_signed<T>::type> {};
  template <typename T> struct make_signed<volatile T> : add_volatile<typename make_signed<T>::type> {};
  template <typename T> struct make_signed<const volatile T> : add_const<typename add_volatile<typename make_signed<T>::type>::type> {};

  /// make_unsigned
  ///\ingroup type_traits
  template <typename T> struct make_unsigned { typedef  T type; };
  template <> struct make_unsigned<char> { typedef unsigned char type; };
  template <> struct make_unsigned<signed char> { typedef unsigned char type; };
  template <> struct make_unsigned<short> { typedef unsigned short type; };
#ifdef COMPILER_MICROSOFT
  template <> struct make_unsigned<wchar_t> { typedef unsigned short type; };
#endif
  template <> struct make_unsigned<int> { typedef unsigned int type; };
  template <> struct make_unsigned<long> { typedef unsigned long type; };
  template <> struct make_unsigned<long long> { typedef unsigned long long type; };
  template <typename T> struct make_unsigned<const T> : add_const<typename make_unsigned<T>::type> {};
  template <typename T> struct make_unsigned<volatile T> : add_volatile<typename make_unsigned<T>::type> {};
  template <typename T> struct make_unsigned<const volatile T> : add_const<typename add_volatile<typename make_unsigned<T>::type>::type> {};

  /// enable_if
  ///\ingroup type_traits
  template <bool B, typename T = void> struct enable_if {};
  template <typename T> struct enable_if<true, T> { typedef T type; };

  /// conditional
  ///\ingroup type_traits
  template <bool B, typename T, typename F>  struct conditional { typedef T type; };
  template <typename T, typename F> struct conditional<false, T, F> { typedef F type; };

  /// extent
  ///\ingroup type_traits
  template <typename T, size_t N = 0>
  struct extent : integral_constant<size_t, 0> {};

  template <typename T>
  struct extent<T[], 0> : integral_constant<size_t, 0> {};

  template <typename T, size_t N>
  struct extent<T[], N> : integral_constant<size_t, extent<T, N - 1>::value> {};

  template <typename T, size_t N>
  struct extent<T[N], 0> : integral_constant<size_t, N> {};

  template <typename T, size_t I, size_t N>
  struct extent<T[I], N> : integral_constant<size_t, extent<T, N - 1>::value> {};

  /// remove_extent
  ///\ingroup type_traits
  template <typename T> struct remove_extent { typedef T type; };
  template <typename T> struct remove_extent<T[]> { typedef T type; };
  template <typename T, size_t N> struct remove_extent<T[N]> { typedef T type;};

  /// remove_all_extents
  ///\ingroup type_traits
  template <typename T> struct remove_all_extents { typedef T type;};
  template <typename T> struct remove_all_extents<T[]> { typedef typename remove_all_extents<T>::type type; };
  template <typename T, size_t N> struct remove_all_extents<T[N]> { typedef typename remove_all_extents<T>::type type; };

  /// rank
  ///\ingroup type_traits
  template <typename T>struct rank : integral_constant<size_t, 0> {};
  template <typename T> struct rank<T[]> : public integral_constant<size_t, rank<T>::value + 1> {};
  template <typename T, size_t N> struct rank<T[N]> : public integral_constant<size_t, rank<T>::value + 1> {};

  /// decay
  ///\ingroup type_traits
  template <typename T>
  struct decay
  {
    typedef typename etl::remove_reference<T>::type U;
    typedef typename etl::conditional<etl::is_array<U>::value,
                                      typename etl::remove_extent<U>::type*,
                                      typename etl::remove_cv<U>::type>::type type;
  };

  /// Alignment templates.
  /// These require compiler specific intrinsics.
  ///\ingroup type_traits
#ifdef COMPILER_MICROSOFT
  template <typename T> struct alignment_of : integral_constant<size_t, size_t(__alignof(T))> {};
#endif

#ifdef COMPILER_GCC
  template <typename T> struct alignment_of : integral_constant<size_t, size_t(__alignof__(T))> {};
#endif
	
#ifdef COMPILER_KEIL
  template <typename T> struct alignment_of : integral_constant<size_t, size_t(__alignof__(T))> {};
#endif

#ifdef COMPILER_IAR
  template <typename T> struct alignment_of : integral_constant<size_t, size_t(__ALIGNOF__(T))> {};
#endif

  /// Specialisation of 'alignment_of' for 'void'.
  ///\ingroup type_traits
  template <> struct alignment_of<void> : integral_constant <size_t, 0>{};
}

#endif