mingw/lib/gcc/mingw32/4.3.3/include/c++/ext/numeric_traits.h

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2007 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the terms
   7 // of the GNU General Public License as published by the Free Software
   8 // Foundation; either version 2, or (at your option) any later
   9 // version.
  10
  11 // This library is distributed in the hope that it will be useful, but
  12 // WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 // General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free
  22 // software library without restriction.  Specifically, if other files
  23 // instantiate templates or use macros or inline functions from this
  24 // file, or you compile this file and link it with other files to
  25 // produce an executable, this file does not by itself cause the
  26 // resulting executable to be covered by the GNU General Public
  27 // License.  This exception does not however invalidate any other
  28 // reasons why the executable file might be covered by the GNU General
  29 // Public License.
  30
  31 /** @file ext/numeric_traits.h
  32  *  This file is a GNU extension to the Standard C++ Library.
  33  */
  34
  35 #ifndef _EXT_NUMERIC_TRAITS
  36 #define _EXT_NUMERIC_TRAITS 1
  37
  38 #pragma GCC system_header
  39
  40 #include <bits/cpp_type_traits.h>
  41 #include <ext/type_traits.h>
  42
  43 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
  44
  45   // Compile time constants for builtin types.
  46   // Sadly std::numeric_limits member functions cannot be used for this.
  47 #define __glibcxx_signed(_Tp) ((_Tp)(-1) < 0)
  48 #define __glibcxx_digits(_Tp) \
  49   (sizeof(_Tp) * __CHAR_BIT__ - __glibcxx_signed(_Tp))
  50
  51 #define __glibcxx_min(_Tp) \
  52   (__glibcxx_signed(_Tp) ? (_Tp)1 << __glibcxx_digits(_Tp) : (_Tp)0)
  53
  54 #define __glibcxx_max(_Tp) \
  55   (__glibcxx_signed(_Tp) ? \
  56    (((((_Tp)1 << (__glibcxx_digits(_Tp) - 1)) - 1) << 1) + 1) : ~(_Tp)0)
  57
  58   template<typename _Value>
  59     struct __numeric_traits_integer
  60     {
  61       // Only integers for initialization of member constant.
  62       static const _Value __min = __glibcxx_min(_Value);
  63       static const _Value __max = __glibcxx_max(_Value);
  64
  65       // NB: these two also available in std::numeric_limits as compile
  66       // time constants, but <limits> is big and we avoid including it.
  67       static const bool __is_signed = __glibcxx_signed(_Value);
  68       static const int __digits = __glibcxx_digits(_Value);
  69     };
  70
  71   template<typename _Value>
  72     const _Value __numeric_traits_integer<_Value>::__min;
  73
  74   template<typename _Value>
  75     const _Value __numeric_traits_integer<_Value>::__max;
  76
  77   template<typename _Value>
  78     const bool __numeric_traits_integer<_Value>::__is_signed;
  79
  80   template<typename _Value>
  81     const int __numeric_traits_integer<_Value>::__digits;
  82
  83 #undef __glibcxx_signed
  84 #undef __glibcxx_digits
  85 #undef __glibcxx_min
  86 #undef __glibcxx_max
  87
  88 #define __glibcxx_floating(_Tp, _Fval, _Dval, _LDval) \
  89   (std::__are_same<_Tp, float>::__value ? _Fval \
  90    : std::__are_same<_Tp, double>::__value ? _Dval : _LDval)
  91
  92 #define __glibcxx_max_digits10(_Tp) \
  93   (2 + __glibcxx_floating(_Tp, __FLT_MANT_DIG__, __DBL_MANT_DIG__, \
  94                           __LDBL_MANT_DIG__) * 3010 / 10000)
  95
  96 #define __glibcxx_digits10(_Tp) \
  97   __glibcxx_floating(_Tp, __FLT_DIG__, __DBL_DIG__, __LDBL_DIG__)
  98
  99 #define __glibcxx_max_exponent10(_Tp) \
 100   __glibcxx_floating(_Tp, __FLT_MAX_10_EXP__, __DBL_MAX_10_EXP__, \
 101                      __LDBL_MAX_10_EXP__)
 102
 103   template<typename _Value>
 104     struct __numeric_traits_floating
 105     {
 106       // Only floating point types. See N1822.
 107       static const int __max_digits10 = __glibcxx_max_digits10(_Value);
 108
 109       // See above comment...
 110       static const bool __is_signed = true;
 111       static const int __digits10 = __glibcxx_digits10(_Value);
 112       static const int __max_exponent10 = __glibcxx_max_exponent10(_Value);
 113     };
 114
 115   template<typename _Value>
 116     const int __numeric_traits_floating<_Value>::__max_digits10;
 117
 118   template<typename _Value>
 119     const bool __numeric_traits_floating<_Value>::__is_signed;
 120
 121   template<typename _Value>
 122     const int __numeric_traits_floating<_Value>::__digits10;
 123
 124   template<typename _Value>
 125     const int __numeric_traits_floating<_Value>::__max_exponent10;
 126
 127   template<typename _Value>
 128     struct __numeric_traits
 129     : public __conditional_type<std::__is_integer<_Value>::__value,
 130                                 __numeric_traits_integer<_Value>,
 131                                 __numeric_traits_floating<_Value> >::__type
 132     { };
 133
 134 _GLIBCXX_END_NAMESPACE
 135
 136 #undef __glibcxx_floating
 137 #undef __glibcxx_max_digits10
 138 #undef __glibcxx_digits10
 139 #undef __glibcxx_max_exponent10
 140
 141 #endif