numeric_traits.h File Reference

#include <bits/cpp_type_traits.h>
#include <ext/type_traits.h>

Go to the source code of this file.

Macros
#define	__glibcxx_signed(_Tp)   ((_Tp)(-1) < 0)
#define	__glibcxx_digits(_Tp)   (sizeof(_Tp) * __CHAR_BIT__ - __glibcxx_signed(_Tp))
#define	__glibcxx_min(_Tp)   (__glibcxx_signed(_Tp) ? (_Tp)1 << __glibcxx_digits(_Tp) : (_Tp)0)
#define	__glibcxx_max(_Tp)
#define	__glibcxx_floating(_Tp, _Fval, _Dval, _LDval)
#define	__glibcxx_max_digits10(_Tp)
#define	__glibcxx_digits10(_Tp)   __glibcxx_floating(_Tp, __FLT_DIG__, __DBL_DIG__, __LDBL_DIG__)
#define	__glibcxx_max_exponent10(_Tp)

Functions
namespace __gnu_cxx	_GLIBCXX_VISIBILITY (default)

Detailed Description

This file is a GNU extension to the Standard C++ Library.

Macro Definition Documentation

#define __glibcxx_digits

(

_Tp

)

(sizeof(_Tp) * __CHAR_BIT__ - __glibcxx_signed(_Tp))

#define __glibcxx_digits10

(

_Tp

)

__glibcxx_floating(_Tp, __FLT_DIG__, __DBL_DIG__, __LDBL_DIG__)

#define __glibcxx_floating	(		_Tp,
			_Fval,
			_Dval,
			_LDval
	)

Value:

(std::__are_same<_Tp, float>::__value ? _Fval \
   : std::__are_same<_Tp, double>::__value ? _Dval : _LDval)

#define __glibcxx_max

(

_Tp

)

Value:

(__glibcxx_signed(_Tp) ? \
   (((((_Tp)1 << (__glibcxx_digits(_Tp) - 1)) - 1) << 1) + 1) : ~(_Tp)0)

#define __glibcxx_max_digits10

(

_Tp

)

Value:

(2 + __glibcxx_floating(_Tp, __FLT_MANT_DIG__, __DBL_MANT_DIG__, \
              __LDBL_MANT_DIG__) * 643L / 2136)

#define __glibcxx_max_exponent10

(

_Tp

)

Value:

__glibcxx_floating(_Tp, __FLT_MAX_10_EXP__, __DBL_MAX_10_EXP__, \
             __LDBL_MAX_10_EXP__)

#define __glibcxx_min

(

_Tp

)

(__glibcxx_signed(_Tp) ? (_Tp)1 << __glibcxx_digits(_Tp) : (_Tp)0)

#define __glibcxx_signed

(

_Tp

)

((_Tp)(-1) < 0)

Function Documentation

namespace __gnu_cxx _GLIBCXX_VISIBILITY

(

default

)

{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  // Compile time constants for builtin types.
  // Sadly std::numeric_limits member functions cannot be used for this.
#define __glibcxx_signed(_Tp) ((_Tp)(-1) < 0)
#define __glibcxx_digits(_Tp) \
  (sizeof(_Tp) * __CHAR_BIT__ - __glibcxx_signed(_Tp))

#define __glibcxx_min(_Tp) \
  (__glibcxx_signed(_Tp) ? (_Tp)1 << __glibcxx_digits(_Tp) : (_Tp)0)

#define __glibcxx_max(_Tp) \
  (__glibcxx_signed(_Tp) ? \
   (((((_Tp)1 << (__glibcxx_digits(_Tp) - 1)) - 1) << 1) + 1) : ~(_Tp)0)

  template<typename _Value>
    struct __numeric_traits_integer
    {
      // Only integers for initialization of member constant.
      static const _Value __min = __glibcxx_min(_Value);
      static const _Value __max = __glibcxx_max(_Value);

      // NB: these two also available in std::numeric_limits as compile
      // time constants, but <limits> is big and we avoid including it.
      static const bool __is_signed = __glibcxx_signed(_Value);
      static const int __digits = __glibcxx_digits(_Value);      
    };

  template<typename _Value>
    const _Value __numeric_traits_integer<_Value>::__min;

  template<typename _Value>
    const _Value __numeric_traits_integer<_Value>::__max;

  template<typename _Value>
    const bool __numeric_traits_integer<_Value>::__is_signed;

  template<typename _Value>
    const int __numeric_traits_integer<_Value>::__digits;

#undef __glibcxx_signed
#undef __glibcxx_digits
#undef __glibcxx_min
#undef __glibcxx_max

#define __glibcxx_floating(_Tp, _Fval, _Dval, _LDval) \
  (std::__are_same<_Tp, float>::__value ? _Fval \
   : std::__are_same<_Tp, double>::__value ? _Dval : _LDval)

#define __glibcxx_max_digits10(_Tp) \
  (2 + __glibcxx_floating(_Tp, __FLT_MANT_DIG__, __DBL_MANT_DIG__, \
              __LDBL_MANT_DIG__) * 643L / 2136)

#define __glibcxx_digits10(_Tp) \
  __glibcxx_floating(_Tp, __FLT_DIG__, __DBL_DIG__, __LDBL_DIG__)

#define __glibcxx_max_exponent10(_Tp) \
  __glibcxx_floating(_Tp, __FLT_MAX_10_EXP__, __DBL_MAX_10_EXP__, \
             __LDBL_MAX_10_EXP__)

  template<typename _Value>
    struct __numeric_traits_floating
    {
      // Only floating point types. See N1822. 
      static const int __max_digits10 = __glibcxx_max_digits10(_Value);

      // See above comment...
      static const bool __is_signed = true;
      static const int __digits10 = __glibcxx_digits10(_Value);
      static const int __max_exponent10 = __glibcxx_max_exponent10(_Value);
    };

  template<typename _Value>
    const int __numeric_traits_floating<_Value>::__max_digits10;

  template<typename _Value>
    const bool __numeric_traits_floating<_Value>::__is_signed;

  template<typename _Value>
    const int __numeric_traits_floating<_Value>::__digits10;

  template<typename _Value>
    const int __numeric_traits_floating<_Value>::__max_exponent10;

  template<typename _Value>
    struct __numeric_traits
    : public __conditional_type<std::__is_integer<_Value>::__value,
                __numeric_traits_integer<_Value>,
                __numeric_traits_floating<_Value> >::__type
    { };

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace