boost/detail/limits.hpp
// Copyright 2001 John Maddock
// Distributed under the Boost Software License, Version 1.0. (See accompany-
// ing file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
/*
* 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, and this file is written for the MIPS
* architecture and the SGI MIPSpro C++ compiler. Parts of it (in
* particular, some of the characteristics of floating-point types)
* are almost certainly incorrect for any other platform.
*/
/* The above comment is almost certainly out of date. This file works
* on systems other than SGI MIPSpro C++ now.
*/
/*
* Revision history:
* 21 Sep 2001:
* Only include <cwchar> if BOOST_NO_CWCHAR is defined. (Darin Adler)
* 10 Aug 2001:
* Added MIPS (big endian) to the big endian family. (Jens Maurer)
* 13 Apr 2001:
* Added powerpc to the big endian family. (Jeremy Siek)
* 5 Apr 2001:
* Added sparc (big endian) processor support (John Maddock).
* Initial sub:
* Modified by Jens Maurer for gcc 2.95 on x86.
*/
#ifndef BOOST_SGI_CPP_LIMITS
#define BOOST_SGI_CPP_LIMITS
#include <climits>
#include <cfloat>
#include <boost/config.hpp>
#include <boost/detail/endian.hpp>
#ifndef BOOST_NO_CWCHAR
#include <cwchar> // for WCHAR_MIN and WCHAR_MAX
#endif
namespace std {
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
// BOOST_NO_INCLASS_MEMBER_INITIALIZATION 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 BOOST_NO_INCLASS_MEMBER_INITIALIZATION
# define BOOST_STL_DECLARE_LIMITS_MEMBER(__mem_type, __mem_name, __mem_value) \
enum { __mem_name = __mem_value }
#else /* BOOST_NO_INCLASS_MEMBER_INITIALIZATION */
# define BOOST_STL_DECLARE_LIMITS_MEMBER(__mem_type, __mem_name, __mem_value) \
static const __mem_type __mem_name = __mem_value
#endif /* BOOST_NO_INCLASS_MEMBER_INITIALIZATION */
// Base class for all specializations of numeric_limits.
template <class __number>
class _Numeric_limits_base {
public:
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_specialized, false);
static __number min BOOST_PREVENT_MACRO_SUBSTITUTION () throw() { return __number(); }
static __number max BOOST_PREVENT_MACRO_SUBSTITUTION () throw() { return __number(); }
BOOST_STL_DECLARE_LIMITS_MEMBER(int, digits, 0);
BOOST_STL_DECLARE_LIMITS_MEMBER(int, digits10, 0);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_signed, false);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_integer, false);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_exact, false);
BOOST_STL_DECLARE_LIMITS_MEMBER(int, radix, 0);
static __number epsilon() throw() { return __number(); }
static __number round_error() throw() { return __number(); }
BOOST_STL_DECLARE_LIMITS_MEMBER(int, min_exponent, 0);
BOOST_STL_DECLARE_LIMITS_MEMBER(int, min_exponent10, 0);
BOOST_STL_DECLARE_LIMITS_MEMBER(int, max_exponent, 0);
BOOST_STL_DECLARE_LIMITS_MEMBER(int, max_exponent10, 0);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, has_infinity, false);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, has_quiet_NaN, false);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, has_signaling_NaN, false);
BOOST_STL_DECLARE_LIMITS_MEMBER(float_denorm_style,
has_denorm,
denorm_absent);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, has_denorm_loss, false);
static __number infinity() throw() { return __number(); }
static __number quiet_NaN() throw() { return __number(); }
static __number signaling_NaN() throw() { return __number(); }
static __number denorm_min() throw() { return __number(); }
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_iec559, false);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_bounded, false);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_modulo, false);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, traps, false);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, tinyness_before, false);
BOOST_STL_DECLARE_LIMITS_MEMBER(float_round_style,
round_style,
round_toward_zero);
};
// Base class for integers.
template <class _Int,
_Int __imin,
_Int __imax,
int __idigits = -1>
class _Integer_limits : public _Numeric_limits_base<_Int>
{
public:
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_specialized, true);
static _Int min BOOST_PREVENT_MACRO_SUBSTITUTION () throw() { return __imin; }
static _Int max BOOST_PREVENT_MACRO_SUBSTITUTION () throw() { return __imax; }
BOOST_STL_DECLARE_LIMITS_MEMBER(int,
digits,
(__idigits < 0) ? (int)(sizeof(_Int) * CHAR_BIT)
- (__imin == 0 ? 0 : 1)
: __idigits);
BOOST_STL_DECLARE_LIMITS_MEMBER(int, digits10, (digits * 301) / 1000);
// log 2 = 0.301029995664...
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_signed, __imin != 0);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_integer, true);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_exact, true);
BOOST_STL_DECLARE_LIMITS_MEMBER(int, radix, 2);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_bounded, true);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_modulo, true);
};
#if defined(BOOST_BIG_ENDIAN)
template<class Number, unsigned int Word>
struct float_helper{
static Number get_word() throw() {
// sizeof(long double) == 16
const unsigned int _S_word[4] = { Word, 0, 0, 0 };
return *reinterpret_cast<const Number*>(&_S_word);
}
};
#else
template<class Number, unsigned int Word>
struct float_helper{
static Number get_word() throw() {
// sizeof(long double) == 12, but only 10 bytes significant
const unsigned int _S_word[4] = { 0, 0, 0, Word };
return *reinterpret_cast<const Number*>(
reinterpret_cast<const char *>(&_S_word)+16-
(sizeof(Number) == 12 ? 10 : sizeof(Number)));
}
};
#endif
// Base class for floating-point numbers.
template <class __number,
int __Digits, int __Digits10,
int __MinExp, int __MaxExp,
int __MinExp10, int __MaxExp10,
unsigned int __InfinityWord,
unsigned int __QNaNWord, unsigned int __SNaNWord,
bool __IsIEC559,
float_round_style __RoundStyle>
class _Floating_limits : public _Numeric_limits_base<__number>
{
public:
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_specialized, true);
BOOST_STL_DECLARE_LIMITS_MEMBER(int, digits, __Digits);
BOOST_STL_DECLARE_LIMITS_MEMBER(int, digits10, __Digits10);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_signed, true);
BOOST_STL_DECLARE_LIMITS_MEMBER(int, radix, 2);
BOOST_STL_DECLARE_LIMITS_MEMBER(int, min_exponent, __MinExp);
BOOST_STL_DECLARE_LIMITS_MEMBER(int, max_exponent, __MaxExp);
BOOST_STL_DECLARE_LIMITS_MEMBER(int, min_exponent10, __MinExp10);
BOOST_STL_DECLARE_LIMITS_MEMBER(int, max_exponent10, __MaxExp10);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, has_infinity, true);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, has_quiet_NaN, true);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, has_signaling_NaN, true);
BOOST_STL_DECLARE_LIMITS_MEMBER(float_denorm_style,
has_denorm,
denorm_indeterminate);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, has_denorm_loss, false);
static __number infinity() throw() {
return float_helper<__number, __InfinityWord>::get_word();
}
static __number quiet_NaN() throw() {
return float_helper<__number,__QNaNWord>::get_word();
}
static __number signaling_NaN() throw() {
return float_helper<__number,__SNaNWord>::get_word();
}
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_iec559, __IsIEC559);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, is_bounded, true);
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, traps, false /* was: true */ );
BOOST_STL_DECLARE_LIMITS_MEMBER(bool, tinyness_before, false);
BOOST_STL_DECLARE_LIMITS_MEMBER(float_round_style, round_style, __RoundStyle);
};
// Class numeric_limits
// The unspecialized class.
template<class T>
class numeric_limits : public _Numeric_limits_base<T> {};
// Specializations for all built-in integral types.
template<>
class numeric_limits<bool>
: public _Integer_limits<bool, false, true, 0>
{};
template<>
class numeric_limits<char>
: public _Integer_limits<char, CHAR_MIN, CHAR_MAX>
{};
template<>
class numeric_limits<signed char>
: public _Integer_limits<signed char, SCHAR_MIN, SCHAR_MAX>
{};
template<>
class numeric_limits<unsigned char>
: public _Integer_limits<unsigned char, 0, UCHAR_MAX>
{};
#ifndef BOOST_NO_INTRINSIC_WCHAR_T
template<>
class numeric_limits<wchar_t>
#if !defined(WCHAR_MAX) || !defined(WCHAR_MIN)
#if defined(_WIN32) || defined(__CYGWIN__)
: public _Integer_limits<wchar_t, 0, USHRT_MAX>
#elif defined(__hppa)
// wchar_t has "unsigned int" as the underlying type
: public _Integer_limits<wchar_t, 0, UINT_MAX>
#else
// assume that wchar_t has "int" as the underlying type
: public _Integer_limits<wchar_t, INT_MIN, INT_MAX>
#endif
#else
// we have WCHAR_MIN and WCHAR_MAX defined, so use it
: public _Integer_limits<wchar_t, WCHAR_MIN, WCHAR_MAX>
#endif
{};
#endif
template<>
class numeric_limits<short>
: public _Integer_limits<short, SHRT_MIN, SHRT_MAX>
{};
template<>
class numeric_limits<unsigned short>
: public _Integer_limits<unsigned short, 0, USHRT_MAX>
{};
template<>
class numeric_limits<int>
: public _Integer_limits<int, INT_MIN, INT_MAX>
{};
template<>
class numeric_limits<unsigned int>
: public _Integer_limits<unsigned int, 0, UINT_MAX>
{};
template<>
class numeric_limits<long>
: public _Integer_limits<long, LONG_MIN, LONG_MAX>
{};
template<>
class numeric_limits<unsigned long>
: public _Integer_limits<unsigned long, 0, ULONG_MAX>
{};
#ifdef __GNUC__
// Some compilers have long long, but don't define the
// LONGLONG_MIN and LONGLONG_MAX macros in limits.h. This
// assumes that long long is 64 bits.
#if !defined(LONGLONG_MAX) && !defined(ULONGLONG_MAX)
# define ULONGLONG_MAX 0xffffffffffffffffLLU
# define LONGLONG_MAX 0x7fffffffffffffffLL
#endif
#if !defined(LONGLONG_MIN)
# define LONGLONG_MIN (-LONGLONG_MAX - 1)
#endif
#if !defined(ULONGLONG_MIN)
# define ULONGLONG_MIN 0
#endif
#endif /* __GNUC__ */
// Specializations for all built-in floating-point type.
template<> class numeric_limits<float>
: public _Floating_limits<float,
FLT_MANT_DIG, // Binary digits of precision
FLT_DIG, // Decimal digits of precision
FLT_MIN_EXP, // Minimum exponent
FLT_MAX_EXP, // Maximum exponent
FLT_MIN_10_EXP, // Minimum base 10 exponent
FLT_MAX_10_EXP, // Maximum base 10 exponent
#if defined(BOOST_BIG_ENDIAN)
0x7f80 << (sizeof(int)*CHAR_BIT-16), // Last word of +infinity
0x7f81 << (sizeof(int)*CHAR_BIT-16), // Last word of quiet NaN
0x7fc1 << (sizeof(int)*CHAR_BIT-16), // Last word of signaling NaN
#else
0x7f800000u, // Last word of +infinity
0x7f810000u, // Last word of quiet NaN
0x7fc10000u, // Last word of signaling NaN
#endif
true, // conforms to iec559
round_to_nearest>
{
public:
static float min BOOST_PREVENT_MACRO_SUBSTITUTION () throw() { return FLT_MIN; }
static float denorm_min() throw() { return FLT_MIN; }
static float max BOOST_PREVENT_MACRO_SUBSTITUTION () throw() { return FLT_MAX; }
static float epsilon() throw() { return FLT_EPSILON; }
static float round_error() throw() { return 0.5f; } // Units: ulps.
};
template<> class numeric_limits<double>
: public _Floating_limits<double,
DBL_MANT_DIG, // Binary digits of precision
DBL_DIG, // Decimal digits of precision
DBL_MIN_EXP, // Minimum exponent
DBL_MAX_EXP, // Maximum exponent
DBL_MIN_10_EXP, // Minimum base 10 exponent
DBL_MAX_10_EXP, // Maximum base 10 exponent
#if defined(BOOST_BIG_ENDIAN)
0x7ff0 << (sizeof(int)*CHAR_BIT-16), // Last word of +infinity
0x7ff1 << (sizeof(int)*CHAR_BIT-16), // Last word of quiet NaN
0x7ff9 << (sizeof(int)*CHAR_BIT-16), // Last word of signaling NaN
#else
0x7ff00000u, // Last word of +infinity
0x7ff10000u, // Last word of quiet NaN
0x7ff90000u, // Last word of signaling NaN
#endif
true, // conforms to iec559
round_to_nearest>
{
public:
static double min BOOST_PREVENT_MACRO_SUBSTITUTION () throw() { return DBL_MIN; }
static double denorm_min() throw() { return DBL_MIN; }
static double max BOOST_PREVENT_MACRO_SUBSTITUTION () throw() { return DBL_MAX; }
static double epsilon() throw() { return DBL_EPSILON; }
static double round_error() throw() { return 0.5; } // Units: ulps.
};
template<> class numeric_limits<long double>
: public _Floating_limits<long double,
LDBL_MANT_DIG, // Binary digits of precision
LDBL_DIG, // Decimal digits of precision
LDBL_MIN_EXP, // Minimum exponent
LDBL_MAX_EXP, // Maximum exponent
LDBL_MIN_10_EXP,// Minimum base 10 exponent
LDBL_MAX_10_EXP,// Maximum base 10 exponent
#if defined(BOOST_BIG_ENDIAN)
0x7ff0 << (sizeof(int)*CHAR_BIT-16), // Last word of +infinity
0x7ff1 << (sizeof(int)*CHAR_BIT-16), // Last word of quiet NaN
0x7ff9 << (sizeof(int)*CHAR_BIT-16), // Last word of signaling NaN
#else
0x7fff8000u, // Last word of +infinity
0x7fffc000u, // Last word of quiet NaN
0x7fff9000u, // Last word of signaling NaN
#endif
false, // Doesn't conform to iec559
round_to_nearest>
{
public:
static long double min BOOST_PREVENT_MACRO_SUBSTITUTION () throw() { return LDBL_MIN; }
static long double denorm_min() throw() { return LDBL_MIN; }
static long double max BOOST_PREVENT_MACRO_SUBSTITUTION () throw() { return LDBL_MAX; }
static long double epsilon() throw() { return LDBL_EPSILON; }
static long double round_error() throw() { return 4; } // Units: ulps.
};
} // namespace std
#endif /* BOOST_SGI_CPP_LIMITS */
// Local Variables:
// mode:C++
// End: