00001 // -*- C++ -*- 00002 00003 // Copyright (C) 2007 Free Software Foundation, Inc. 00004 // 00005 // This file is part of the GNU ISO C++ Library. This library is free 00006 // software; you can redistribute it and/or modify it under the terms 00007 // of the GNU General Public License as published by the Free Software 00008 // Foundation; either version 2, or (at your option) any later 00009 // version. 00010 00011 // This library is distributed in the hope that it will be useful, but 00012 // WITHOUT ANY WARRANTY; without even the implied warranty of 00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00014 // General Public License for more details. 00015 00016 // You should have received a copy of the GNU General Public License along 00017 // with this library; see the file COPYING. If not, write to the Free 00018 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 00019 // USA. 00020 00021 // As a special exception, you may use this file as part of a free 00022 // software library without restriction. Specifically, if other files 00023 // instantiate templates or use macros or inline functions from this 00024 // file, or you compile this file and link it with other files to 00025 // produce an executable, this file does not by itself cause the 00026 // resulting executable to be covered by the GNU General Public 00027 // License. This exception does not however invalidate any other 00028 // reasons why the executable file might be covered by the GNU General 00029 // Public License. 00030 00031 /** @file ext/numeric_traits.h 00032 * This file is a GNU extension to the Standard C++ Library. 00033 */ 00034 00035 #ifndef _EXT_NUMERIC_TRAITS 00036 #define _EXT_NUMERIC_TRAITS 1 00037 00038 #pragma GCC system_header 00039 00040 #include <limits> 00041 #include <bits/cpp_type_traits.h> 00042 #include <ext/type_traits.h> 00043 00044 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx) 00045 00046 // Compile time constants for builtin types. 00047 // Sadly std::numeric_limits member functions cannot be used for this. 00048 #define __glibcxx_signed(_Tp) ((_Tp)(-1) < 0) 00049 #define __glibcxx_digits(_Tp) \ 00050 (sizeof(_Tp) * __CHAR_BIT__ - __glibcxx_signed(_Tp)) 00051 00052 #define __glibcxx_min(_Tp) \ 00053 (__glibcxx_signed(_Tp) ? (_Tp)1 << __glibcxx_digits(_Tp) : (_Tp)0) 00054 00055 #define __glibcxx_max(_Tp) \ 00056 (__glibcxx_signed(_Tp) ? \ 00057 (((((_Tp)1 << (__glibcxx_digits(_Tp) - 1)) - 1) << 1) + 1) : ~(_Tp)0) 00058 00059 template<typename _Value> 00060 struct __numeric_traits_integer 00061 { 00062 // Only integers for initialization of member constant. 00063 static const _Value __min = __glibcxx_min(_Value); 00064 static const _Value __max = __glibcxx_max(_Value); 00065 }; 00066 00067 template<typename _Value> 00068 const _Value __numeric_traits_integer<_Value>::__min; 00069 00070 template<typename _Value> 00071 const _Value __numeric_traits_integer<_Value>::__max; 00072 00073 template<typename _Value> 00074 struct __numeric_traits_floating 00075 { 00076 // Only floating point types. See N1822. 00077 static const int __max_digits10 = 00078 2 + std::numeric_limits<_Value>::digits * 3010/10000; 00079 }; 00080 00081 template<typename _Value> 00082 const int __numeric_traits_floating<_Value>::__max_digits10; 00083 00084 template<typename _Value> 00085 struct __numeric_traits 00086 : public __conditional_type<std::__is_integer<_Value>::__value, 00087 __numeric_traits_integer<_Value>, 00088 __numeric_traits_floating<_Value> >::__type 00089 { }; 00090 00091 _GLIBCXX_END_NAMESPACE 00092 00093 #undef __glibcxx_signed 00094 #undef __glibcxx_min 00095 #undef __glibcxx_max 00096 #undef __glibcxx_digits 00097 00098 #endif