_limits.c

stl的源码

//    return get_word_higher();
//#    else /* _STLP_LITTLE_ENDIAN */
    return get_word_lower();
//#    endif
  }
};
#  endif

/* Former values kept in case moving to boost code has introduce a regression on
 * some platform. */
#if 0
#  if defined (_STLP_BIG_ENDIAN)
#    if defined (__OS400__)
#      define _STLP_FLOAT_INF_REP { 0x7f80, 0 }
#      define _STLP_FLOAT_QNAN_REP { 0xffc0, 0 }
#      define _STLP_FLOAT_SNAN_REP { 0xff80, 0 }
#      define _STLP_DOUBLE_INF_REP { 0x7ff0, 0, 0, 0 }
#      define _STLP_DOUBLE_QNAN_REP { 0xfff8, 0, 0, 0 }
#      define _STLP_DOUBLE_SNAN_REP { 0xfff0, 0, 0, 0 }
#      define _STLP_LDOUBLE_INF_REP { 0x7ff0, 0, 0, 0, 0, 0, 0, 0 }
#      define _STLP_LDOUBLE_QNAN_REP { 0xfff8, 0, 0, 0, 0, 0, 0, 0 }
#      define _STLP_LDOUBLE_SNAN_REP { 0xfff0, 0, 0, 0, 0, 0, 0, 0 }
#    else /* __OS400__ */
#      define _STLP_FLOAT_INF_REP   { 0x7f80, 0 }
#      define _STLP_FLOAT_QNAN_REP  { 0x7fc1, 0 }
#      define _STLP_FLOAT_SNAN_REP  { 0x7f81, 0 }
#      define _STLP_DOUBLE_INF_REP  { 0x7ff0, 0, 0, 0 }
#      define _STLP_DOUBLE_QNAN_REP { 0x7ff9, 0, 0, 0 }
#      define _STLP_DOUBLE_SNAN_REP { 0x7ff1, 0, 0, 0 }
#      define _STLP_LDOUBLE_INF_REP { 0x7ff0, 0, 0, 0, 0, 0, 0, 0 }
#      define _STLP_LDOUBLE_QNAN_REP { 0x7ff1, 0, 0, 0, 0, 0, 0, 0 }
#      define _STLP_LDOUBLE_SNAN_REP { 0x7ff9, 0, 0, 0, 0, 0, 0, 0 }
#    endif /* __OS400__ */
#  else /* _STLP_LITTLE_ENDIAN */
#    if defined(__DECCXX)
#      define _STLP_FLOAT_INF_REP { 0, 0x7f80 }
#      define _STLP_FLOAT_QNAN_REP { 0, 0xffc0 }
#      define _STLP_FLOAT_SNAN_REP { 0x5555, 0x7f85 }
#      define _STLP_DOUBLE_INF_REP { 0, 0, 0, 0x7ff0 }
#      define _STLP_DOUBLE_QNAN_REP { 0, 0, 0, 0xfff8 }
#      define _STLP_DOUBLE_SNAN_REP { 0x5555, 0x5555, 0x5555, 0x7ff5 }
#      define _STLP_LDOUBLE_INF_REP { 0, 0, 0, 0, 0, 0, 0, 0x7fff }
#      define _STLP_LDOUBLE_QNAN_REP { 0, 0, 0, 0, 0, 0, 0x8000, 0xffff }
#      define _STLP_LDOUBLE_SNAN_REP { 0x5555, 0x5555, 0x5555, 0x5555, 0x5555, 0x5555, 0x5555, 0x7fff}
#    else
#      define _STLP_FLOAT_INF_REP { 0, 0x7f80 }
#      define _STLP_FLOAT_QNAN_REP { 0, 0x7fc0 }
#      define _STLP_FLOAT_SNAN_REP { 0, 0x7fa0 }
#      define _STLP_DOUBLE_INF_REP { 0, 0, 0, 0x7ff0 }
#      define _STLP_DOUBLE_QNAN_REP { 0, 0, 0, 0x7ff8 }
#      define _STLP_DOUBLE_SNAN_REP { 0, 0, 0, 0x7ff4 }
#      if defined (_STLP_MSVC) || defined (__ICL)
#        define _STLP_LDOUBLE_INF_REP { 0, 0, 0, 0x7FF0, 0 }
#        define _STLP_LDOUBLE_QNAN_REP { 0, 0, 0, 0xFFF8, 0 }
#        define _STLP_LDOUBLE_SNAN_REP { 0, 0, 0, 0xFFF8, 0 }
#      elif defined (__BORLANDC__)
#        define _STLP_LDOUBLE_INF_REP { 0, 0, 0, 0x8000, 0x7fff }
#        define _STLP_LDOUBLE_QNAN_REP { 0, 0, 0, 0xc000, 0x7fff }
#        define _STLP_LDOUBLE_SNAN_REP { 0, 0, 0, 0xa000, 0x7fff }
#      else
#        define _STLP_LDOUBLE_INF_REP { 0, 0, 0, 0x8000, 0x7fff, 0 }
#        define _STLP_LDOUBLE_QNAN_REP { 0, 0, 0, 0xa000, 0x7fff, 0 }
#        define _STLP_LDOUBLE_SNAN_REP { 0, 0, 0, 0xc000, 0x7fff, 0 }
#      endif
#    endif
#  endif

union _F_rep {
  unsigned short rep[2];
  float val;
};
union _D_rep {
  unsigned short rep[4];
  double val;
};

#  ifndef _STLP_NO_LONG_DOUBLE
union _LD_rep {
  unsigned short rep[8];
  long double val;
};
#  endif
#endif

template <class __dummy>
float _STLP_CALL _LimG<__dummy>::get_F_inf() {
  typedef float_helper<float, 0x7f80u> _FloatHelper;
  return _FloatHelper::get_from_last_word();
}
template <class __dummy>
float _STLP_CALL _LimG<__dummy>::get_F_qNaN() {
  typedef float_helper<float, 0x7f81u> _FloatHelper;
  return _FloatHelper::get_from_last_word();
}
template <class __dummy>
float _STLP_CALL _LimG<__dummy>::get_F_sNaN() {
  typedef float_helper<float, 0x7fc1u> _FloatHelper;
  return _FloatHelper::get_from_last_word();
}
template <class __dummy>
float _STLP_CALL _LimG<__dummy>::get_F_denormMin() {
  typedef float_helper<float, 0x0001u> _FloatHelper;
  return _FloatHelper::get_from_first_word();
}

template <int __use_double_limits>
class _NumericLimitsAccess;

_STLP_TEMPLATE_NULL
class _NumericLimitsAccess<1> {
public:
  static double get_inf() {
    typedef float_helper<double, 0x7ff0u> _FloatHelper;
    return _FloatHelper::get_from_last_word();
  }
  static double get_qNaN() {
    typedef float_helper<double, 0x7ff1u> _FloatHelper;
    return _FloatHelper::get_from_last_word();
  }
  static double get_sNaN() {
    typedef float_helper<double, 0x7ff9u> _FloatHelper;
    return _FloatHelper::get_from_last_word();
  }
};

template <class __dummy>
double _STLP_CALL _LimG<__dummy>::get_D_inf()
{ return _NumericLimitsAccess<1>::get_inf(); }
template <class __dummy>
double _STLP_CALL _LimG<__dummy>::get_D_qNaN()
{ return _NumericLimitsAccess<1>::get_qNaN(); }
template <class __dummy>
double _STLP_CALL _LimG<__dummy>::get_D_sNaN()
{ return _NumericLimitsAccess<1>::get_sNaN(); }
template <class __dummy>
double _STLP_CALL _LimG<__dummy>::get_D_denormMin() {
  typedef float_helper<double, 0x0001u> _FloatHelper;
  return _FloatHelper::get_from_first_word();
}

#  if !defined (_STLP_NO_LONG_DOUBLE)
_STLP_TEMPLATE_NULL
class _NumericLimitsAccess<0> {
public:
  static long double get_inf() {
#    if defined (_STLP_BIG_ENDIAN)
    typedef float_helper<long double, 0x7ff0u> _FloatHelper;
#    else
    typedef float_helper2<long double, 0x8000u, 0x7fffu> _FloatHelper;
#    endif
    return _FloatHelper::get_from_last_word();
  }
  static long double get_qNaN() {
#    if defined (_STLP_BIG_ENDIAN)
    typedef float_helper<long double, 0x7ff1u> _FloatHelper;
#    else
    typedef float_helper2<long double, 0xc000u, 0x7fffu> _FloatHelper;
#    endif
    return _FloatHelper::get_from_last_word();
  }
  static long double get_sNaN() {
#    if defined (_STLP_BIG_ENDIAN)
    typedef float_helper<long double, 0x7ff9u> _FloatHelper;
#    else
    typedef float_helper2<long double, 0x9000u, 0x7fffu> _FloatHelper;
#    endif
    return _FloatHelper::get_from_last_word();
  }
};

template <class __dummy>
long double _STLP_CALL _LimG<__dummy>::get_LD_inf() {
  const int __use_double_limits = sizeof(double) == sizeof(long double) ? 1 : 0;
  return _NumericLimitsAccess<__use_double_limits>::get_inf();
}
template <class __dummy>
long double _STLP_CALL _LimG<__dummy>::get_LD_qNaN() {
  const int __use_double_limits = sizeof(double) == sizeof(long double) ? 1 : 0;
  return _NumericLimitsAccess<__use_double_limits>::get_qNaN();
}
template <class __dummy>
long double _STLP_CALL _LimG<__dummy>::get_LD_sNaN() {
  const int __use_double_limits = sizeof(double) == sizeof(long double) ? 1 : 0;
  return _NumericLimitsAccess<__use_double_limits>::get_sNaN();
}
template <class __dummy>
long double _STLP_CALL _LimG<__dummy>::get_LD_denormMin() {
  typedef float_helper<long double, 0x0001u> _FloatHelper;
  return _FloatHelper::get_from_first_word();
}
#  endif

#endif /* _STLP_EXPOSE_GLOBALS_IMPLEMENTATION */

#undef _STLP_LIMITS_MIN_TYPE
#undef _STLP_LIMITS_MAX_TYPE

_STLP_MOVE_TO_STD_NAMESPACE

_STLP_END_NAMESPACE

#endif /* _STLP_LIMITS_C_INCLUDED */