1// -*- C++ -*- 2 3// Copyright (C) 2007, 2008, 2009, 2010 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 3, 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// Under Section 7 of GPL version 3, you are granted additional 17// permissions described in the GCC Runtime Library Exception, version 18// 3.1, as published by the Free Software Foundation. 19 20// You should have received a copy of the GNU General Public License and 21// a copy of the GCC Runtime Library Exception along with this program; 22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23// <http://www.gnu.org/licenses/>. 24 25/** @file ext/numeric_traits.h 26 * This file is a GNU extension to the Standard C++ Library. 27 */ 28 29#ifndef _EXT_NUMERIC_TRAITS 30#define _EXT_NUMERIC_TRAITS 1 31 32#pragma GCC system_header 33 34#include <bits/cpp_type_traits.h> 35#include <ext/type_traits.h> 36 37namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) 38{ 39_GLIBCXX_BEGIN_NAMESPACE_VERSION 40 41 // Compile time constants for builtin types. 42 // Sadly std::numeric_limits member functions cannot be used for this. 43#define __glibcxx_signed(_Tp) ((_Tp)(-1) < 0) 44#define __glibcxx_digits(_Tp) \ 45 (sizeof(_Tp) * __CHAR_BIT__ - __glibcxx_signed(_Tp)) 46 47#define __glibcxx_min(_Tp) \ 48 (__glibcxx_signed(_Tp) ? (_Tp)1 << __glibcxx_digits(_Tp) : (_Tp)0) 49 50#define __glibcxx_max(_Tp) \ 51 (__glibcxx_signed(_Tp) ? \ 52 (((((_Tp)1 << (__glibcxx_digits(_Tp) - 1)) - 1) << 1) + 1) : ~(_Tp)0) 53 54 template<typename _Value> 55 struct __numeric_traits_integer 56 { 57 // Only integers for initialization of member constant. 58 static const _Value __min = __glibcxx_min(_Value); 59 static const _Value __max = __glibcxx_max(_Value); 60 61 // NB: these two also available in std::numeric_limits as compile 62 // time constants, but <limits> is big and we avoid including it. 63 static const bool __is_signed = __glibcxx_signed(_Value); 64 static const int __digits = __glibcxx_digits(_Value); 65 }; 66 67 template<typename _Value> 68 const _Value __numeric_traits_integer<_Value>::__min; 69 70 template<typename _Value> 71 const _Value __numeric_traits_integer<_Value>::__max; 72 73 template<typename _Value> 74 const bool __numeric_traits_integer<_Value>::__is_signed; 75 76 template<typename _Value> 77 const int __numeric_traits_integer<_Value>::__digits; 78 79#undef __glibcxx_signed 80#undef __glibcxx_digits 81#undef __glibcxx_min 82#undef __glibcxx_max 83 84#define __glibcxx_floating(_Tp, _Fval, _Dval, _LDval) \ 85 (std::__are_same<_Tp, float>::__value ? _Fval \ 86 : std::__are_same<_Tp, double>::__value ? _Dval : _LDval) 87 88#define __glibcxx_max_digits10(_Tp) \ 89 (2 + __glibcxx_floating(_Tp, __FLT_MANT_DIG__, __DBL_MANT_DIG__, \ 90 __LDBL_MANT_DIG__) * 643L / 2136) 91 92#define __glibcxx_digits10(_Tp) \ 93 __glibcxx_floating(_Tp, __FLT_DIG__, __DBL_DIG__, __LDBL_DIG__) 94 95#define __glibcxx_max_exponent10(_Tp) \ 96 __glibcxx_floating(_Tp, __FLT_MAX_10_EXP__, __DBL_MAX_10_EXP__, \ 97 __LDBL_MAX_10_EXP__) 98 99 template<typename _Value> 100 struct __numeric_traits_floating 101 { 102 // Only floating point types. See N1822. 103 static const int __max_digits10 = __glibcxx_max_digits10(_Value); 104 105 // See above comment... 106 static const bool __is_signed = true; 107 static const int __digits10 = __glibcxx_digits10(_Value); 108 static const int __max_exponent10 = __glibcxx_max_exponent10(_Value); 109 }; 110 111 template<typename _Value> 112 const int __numeric_traits_floating<_Value>::__max_digits10; 113 114 template<typename _Value> 115 const bool __numeric_traits_floating<_Value>::__is_signed; 116 117 template<typename _Value> 118 const int __numeric_traits_floating<_Value>::__digits10; 119 120 template<typename _Value> 121 const int __numeric_traits_floating<_Value>::__max_exponent10; 122 123 template<typename _Value> 124 struct __numeric_traits 125 : public __conditional_type<std::__is_integer<_Value>::__value, 126 __numeric_traits_integer<_Value>, 127 __numeric_traits_floating<_Value> >::__type 128 { }; 129 130_GLIBCXX_END_NAMESPACE_VERSION 131} // namespace 132 133#undef __glibcxx_floating 134#undef __glibcxx_max_digits10 135#undef __glibcxx_digits10 136#undef __glibcxx_max_exponent10 137 138#endif 139