limits

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/*
 * Copyright (c) 1997
 * Silicon Graphics Computer Systems, Inc.
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Silicon Graphics makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 */

/* NOTE: This is not portable code.  Parts of numeric_limits<> are
 * inherently machine-dependent.  At present this file is suitable
 * for the MIPS and ia32 architectures.
 */

#ifndef __SGI_CPP_LIMITS
#define __SGI_CPP_LIMITS

#include <limits.h>
#include <float.h>
#include <stl_config.h>

__STL_BEGIN_NAMESPACE

enum float_round_style {
  round_indeterminate       = -1,
  round_toward_zero         =  0,
  round_to_nearest          =  1,
  round_toward_infinity     =  2,
  round_toward_neg_infinity =  3
};

enum float_denorm_style {
  denorm_indeterminate = -1,
  denorm_absent        =  0,
  denorm_present       =  1
};

// The C++ standard (section 18.2.1) requires that some of the members of
// numeric_limits be static const data members that are given constant-
// initializers within the class declaration.  On compilers where the
// __STL_STATIC_CONST_INIT_BUG macro is defined, it is impossible to write
// a standard-conforming numeric_limits class.
//
// There are two possible workarounds: either initialize the data
// members outside the class, or change them from data members to
// enums.  Neither workaround is satisfactory: the former makes it
// impossible to use the data members in constant-expressions, and the
// latter means they have the wrong type and that it is impossible to
// take their addresses.  We choose the former workaround.

#ifdef __STL_STATIC_CONST_INIT_BUG
# define __STL_DECLARE_LIMITS_MEMBER(__mem_type, __mem_name, __mem_value) \
  enum { __mem_name = __mem_value }
#else /* __STL_STATIC_CONST_INIT_BUG */
# define __STL_DECLARE_LIMITS_MEMBER(__mem_type, __mem_name, __mem_value) \
  static const __mem_type __mem_name = __mem_value
#endif /* __STL_STATIC_CONST_INIT_BUG */

// Base class for all specializations of numeric_limits.

template <class __number>
class _Numeric_limits_base {
public:
  __STL_DECLARE_LIMITS_MEMBER(bool, is_specialized, false);

  static __number min() __STL_NOTHROW { return __number(); }
  static __number max() __STL_NOTHROW { return __number(); }

  __STL_DECLARE_LIMITS_MEMBER(int, digits,   0);
  __STL_DECLARE_LIMITS_MEMBER(int, digits10, 0);

  __STL_DECLARE_LIMITS_MEMBER(bool, is_signed,  false);
  __STL_DECLARE_LIMITS_MEMBER(bool, is_integer, false);
  __STL_DECLARE_LIMITS_MEMBER(bool, is_exact,   false);

  __STL_DECLARE_LIMITS_MEMBER(int, radix, 0);

  static __number epsilon() __STL_NOTHROW     { return __number(); }
  static __number round_error() __STL_NOTHROW { return __number(); }

  __STL_DECLARE_LIMITS_MEMBER(int, min_exponent,   0);
  __STL_DECLARE_LIMITS_MEMBER(int, min_exponent10, 0);
  __STL_DECLARE_LIMITS_MEMBER(int, max_exponent,   0);
  __STL_DECLARE_LIMITS_MEMBER(int, max_exponent10, 0);

  __STL_DECLARE_LIMITS_MEMBER(bool, has_infinity,      false);
  __STL_DECLARE_LIMITS_MEMBER(bool, has_quiet_NaN,     false);
  __STL_DECLARE_LIMITS_MEMBER(bool, has_signaling_NaN, false);
  __STL_DECLARE_LIMITS_MEMBER(float_denorm_style,
                              has_denorm,
                              denorm_absent);
  __STL_DECLARE_LIMITS_MEMBER(bool, has_denorm_loss,   false);

  static __number infinity() __STL_NOTHROW      { return __number(); }
  static __number quiet_NaN() __STL_NOTHROW     { return __number(); }
  static __number signaling_NaN() __STL_NOTHROW { return __number(); }
  static __number denorm_min() __STL_NOTHROW    { return __number(); }

  __STL_DECLARE_LIMITS_MEMBER(bool, is_iec559,  false);
  __STL_DECLARE_LIMITS_MEMBER(bool, is_bounded, false);
  __STL_DECLARE_LIMITS_MEMBER(bool, is_modulo,  false);

  __STL_DECLARE_LIMITS_MEMBER(bool, traps,            false);
  __STL_DECLARE_LIMITS_MEMBER(bool, tinyness_before,  false);
  __STL_DECLARE_LIMITS_MEMBER(float_round_style,
                              round_style,
                              round_toward_zero);
};

#ifdef __STL_STATIC_CONST_INIT_BUG
# define __STL_DEFINE_NUMERIC_BASE_MEMBER(__type, __mem)
#else /* __STL_STATIC_CONST_INIT_BUG */
# define __STL_DEFINE_NUMERIC_BASE_MEMBER(__type, __mem) \
  template <class __number>                              \
  const __type _Numeric_limits_base<__number>:: __mem
#endif /* __STL_STATIC_CONST_INIT_BUG */

__STL_DEFINE_NUMERIC_BASE_MEMBER(bool, is_specialized);
__STL_DEFINE_NUMERIC_BASE_MEMBER(int, digits);
__STL_DEFINE_NUMERIC_BASE_MEMBER(int, digits10);
__STL_DEFINE_NUMERIC_BASE_MEMBER(bool, is_signed);
__STL_DEFINE_NUMERIC_BASE_MEMBER(bool, is_integer);
__STL_DEFINE_NUMERIC_BASE_MEMBER(bool, is_exact);
__STL_DEFINE_NUMERIC_BASE_MEMBER(int, radix);
__STL_DEFINE_NUMERIC_BASE_MEMBER(int, min_exponent);
__STL_DEFINE_NUMERIC_BASE_MEMBER(int, max_exponent);
__STL_DEFINE_NUMERIC_BASE_MEMBER(int, min_exponent10);
__STL_DEFINE_NUMERIC_BASE_MEMBER(int, max_exponent10);
__STL_DEFINE_NUMERIC_BASE_MEMBER(bool, has_infinity);
__STL_DEFINE_NUMERIC_BASE_MEMBER(bool, has_quiet_NaN);
__STL_DEFINE_NUMERIC_BASE_MEMBER(bool, has_signaling_NaN);
__STL_DEFINE_NUMERIC_BASE_MEMBER(float_denorm_style, has_denorm);
__STL_DEFINE_NUMERIC_BASE_MEMBER(bool, has_denorm_loss);
__STL_DEFINE_NUMERIC_BASE_MEMBER(bool, is_iec559);
__STL_DEFINE_NUMERIC_BASE_MEMBER(bool, is_bounded);
__STL_DEFINE_NUMERIC_BASE_MEMBER(bool, is_modulo);
__STL_DEFINE_NUMERIC_BASE_MEMBER(bool, traps);
__STL_DEFINE_NUMERIC_BASE_MEMBER(bool, tinyness_before);
__STL_DEFINE_NUMERIC_BASE_MEMBER(float_round_style, round_style);


// Base class for integers.

template <class _Int,
          _Int __imin, _Int __imax,
          int __idigits = -1, bool __ismod = true>
class _Integer_limits : public _Numeric_limits_base<_Int> 
{
public:
  __STL_DECLARE_LIMITS_MEMBER(bool, is_specialized, true);

  static _Int min() __STL_NOTHROW { return __imin; }
  static _Int max() __STL_NOTHROW { return __imax; }

  __STL_DECLARE_LIMITS_MEMBER(int,
                              digits,
                              (__idigits < 0) ? (int)(sizeof(_Int) * CHAR_BIT)
                                                   - (__imin == 0 ? 0 : 1) 
                                              : __idigits);
  __STL_DECLARE_LIMITS_MEMBER(int, digits10, (digits * 301) / 1000); 
                                // log 2 = 0.301029995664...

  __STL_DECLARE_LIMITS_MEMBER(bool, is_signed,  __imin != 0);
  __STL_DECLARE_LIMITS_MEMBER(bool, is_integer, true);
  __STL_DECLARE_LIMITS_MEMBER(bool, is_exact,   true);
  __STL_DECLARE_LIMITS_MEMBER(int,  radix,      2);

  __STL_DECLARE_LIMITS_MEMBER(bool, is_bounded, true);
  __STL_DECLARE_LIMITS_MEMBER(bool, is_modulo, __ismod);
};

#ifdef __STL_STATIC_CONST_INIT_BUG
# define __STL_DEFINE_INTEGER_LIMITS_MEMBER(__type, __mem)
#else /* __STL_STATIC_CONST_INIT_BUG */
# define __STL_DEFINE_INTEGER_LIMITS_MEMBER(__type, __mem)              \
  template <class _Int, _Int __imin, _Int __imax, int __idig, bool __ismod>  \
  const __type _Integer_limits<_Int, __imin, __imax, __idig, __ismod>::__mem
#endif /* __STL_STATIC_CONST_INIT_BUG */

__STL_DEFINE_INTEGER_LIMITS_MEMBER(bool, is_specialized);
__STL_DEFINE_INTEGER_LIMITS_MEMBER(int, digits);
__STL_DEFINE_INTEGER_LIMITS_MEMBER(int, digits10);
__STL_DEFINE_INTEGER_LIMITS_MEMBER(bool, is_signed);
__STL_DEFINE_INTEGER_LIMITS_MEMBER(bool, is_integer);
__STL_DEFINE_INTEGER_LIMITS_MEMBER(bool, is_exact);
__STL_DEFINE_INTEGER_LIMITS_MEMBER(int, radix);
__STL_DEFINE_INTEGER_LIMITS_MEMBER(bool, is_bounded);
__STL_DEFINE_INTEGER_LIMITS_MEMBER(bool, is_modulo);


// Base class for floating-point numbers.
template <class __number,
         int __Digits, int __Digits10,
         int __MinExp, int __MaxExp,
         int __MinExp10, int __MaxExp10,
         bool __IsIEC559,
         float_round_style __RoundStyle>
class _Floating_limits : public _Numeric_limits_base<__number>
{
public:
  __STL_DECLARE_LIMITS_MEMBER(bool, is_specialized, true);

  __STL_DECLARE_LIMITS_MEMBER(int, digits,   __Digits);
  __STL_DECLARE_LIMITS_MEMBER(int, digits10, __Digits10);

  __STL_DECLARE_LIMITS_MEMBER(bool, is_signed, true);

  __STL_DECLARE_LIMITS_MEMBER(int, radix, 2);

  __STL_DECLARE_LIMITS_MEMBER(int, min_exponent,   __MinExp);
  __STL_DECLARE_LIMITS_MEMBER(int, max_exponent,   __MaxExp);
  __STL_DECLARE_LIMITS_MEMBER(int, min_exponent10, __MinExp10);
  __STL_DECLARE_LIMITS_MEMBER(int, max_exponent10, __MaxExp10);

  __STL_DECLARE_LIMITS_MEMBER(bool, has_infinity,      true);
  __STL_DECLARE_LIMITS_MEMBER(bool, has_quiet_NaN,     true);
  __STL_DECLARE_LIMITS_MEMBER(bool, has_signaling_NaN, true);
  __STL_DECLARE_LIMITS_MEMBER(float_denorm_style,
                              has_denorm,
                              denorm_indeterminate);
  __STL_DECLARE_LIMITS_MEMBER(bool, has_denorm_loss,   false);

  __STL_DECLARE_LIMITS_MEMBER(bool, is_iec559,       __IsIEC559);
  __STL_DECLARE_LIMITS_MEMBER(bool, is_bounded,      true);
  __STL_DECLARE_LIMITS_MEMBER(bool, traps,           true);
  __STL_DECLARE_LIMITS_MEMBER(bool, tinyness_before, false);

  __STL_DECLARE_LIMITS_MEMBER(float_round_style, round_style, __RoundStyle);
};

#ifdef __STL_STATIC_CONST_INIT_BUG
# define __STL_DEFINE_FLOAT_LIMITS_MEMBER(__type, __mem)
#else /* __STL_STATIC_CONST_INIT_BUG */
# define __STL_DEFINE_FLOAT_LIMITS_MEMBER(__type, __mem)                   \
  template <class __Num, int __Dig, int __Dig10,                           \
            int __MnX, int __MxX, int __MnX10, int __MxX10,                \
            bool __IsIEEE, float_round_style __Sty>                        \
  const __type _Floating_limits<__Num, __Dig, __Dig10,                     \
                                __MnX, __MxX, __MnX10, __MxX10,            \
                                __IsIEEE, __Sty>:: __mem
#endif /* __STL_STATIC_CONST_INIT_BUG */

__STL_DEFINE_FLOAT_LIMITS_MEMBER(bool, is_specialized);  
__STL_DEFINE_FLOAT_LIMITS_MEMBER(int, digits);  
__STL_DEFINE_FLOAT_LIMITS_MEMBER(int, digits10);  
__STL_DEFINE_FLOAT_LIMITS_MEMBER(bool, is_signed);  
__STL_DEFINE_FLOAT_LIMITS_MEMBER(int, radix);  
__STL_DEFINE_FLOAT_LIMITS_MEMBER(int, min_exponent);  
__STL_DEFINE_FLOAT_LIMITS_MEMBER(int, max_exponent);  
__STL_DEFINE_FLOAT_LIMITS_MEMBER(int, min_exponent10);  
__STL_DEFINE_FLOAT_LIMITS_MEMBER(int, max_exponent10);  
__STL_DEFINE_FLOAT_LIMITS_MEMBER(bool, has_infinity);
__STL_DEFINE_FLOAT_LIMITS_MEMBER(bool, has_quiet_NaN);
__STL_DEFINE_FLOAT_LIMITS_MEMBER(bool, has_signaling_NaN);
__STL_DEFINE_FLOAT_LIMITS_MEMBER(float_denorm_style, has_denorm);
__STL_DEFINE_FLOAT_LIMITS_MEMBER(bool, has_denorm_loss);
__STL_DEFINE_FLOAT_LIMITS_MEMBER(bool, is_iec559);
__STL_DEFINE_FLOAT_LIMITS_MEMBER(bool, is_bounded);
__STL_DEFINE_FLOAT_LIMITS_MEMBER(bool, traps);
__STL_DEFINE_FLOAT_LIMITS_MEMBER(bool, tinyness_before);
__STL_DEFINE_FLOAT_LIMITS_MEMBER(float_round_style, round_style);


#undef __STL_DECLARE_NUMERIC_LIMITS_MEMBER
#undef __STL_DEFINE_NUMERIC_BASE_MEMBER