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 <limits> 41#include <bits/cpp_type_traits.h> 42#include <ext/type_traits.h> 43 44_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx) 45 46 // Compile time constants for builtin types. 47 // Sadly std::numeric_limits member functions cannot be used for this. 48#define __glibcxx_signed(_Tp) ((_Tp)(-1) < 0) 49#define __glibcxx_digits(_Tp) \ 50 (sizeof(_Tp) * __CHAR_BIT__ - __glibcxx_signed(_Tp)) 51 52#define __glibcxx_min(_Tp) \ 53 (__glibcxx_signed(_Tp) ? (_Tp)1 << __glibcxx_digits(_Tp) : (_Tp)0) 54 55#define __glibcxx_max(_Tp) \ 56 (__glibcxx_signed(_Tp) ? \ 57 (((((_Tp)1 << (__glibcxx_digits(_Tp) - 1)) - 1) << 1) + 1) : ~(_Tp)0) 58 59 template<typename _Value> 60 struct __numeric_traits_integer 61 { 62 // Only integers for initialization of member constant. 63 static const _Value __min = __glibcxx_min(_Value); 64 static const _Value __max = __glibcxx_max(_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 struct __numeric_traits_floating 75 { 76 // Only floating point types. See N1822. 77 static const int __max_digits10 = 78 2 + std::numeric_limits<_Value>::digits * 3010/10000; 79 }; 80 81 template<typename _Value> 82 const int __numeric_traits_floating<_Value>::__max_digits10; 83 84 template<typename _Value> 85 struct __numeric_traits 86 : public __conditional_type<std::__is_integer<_Value>::__value, 87 __numeric_traits_integer<_Value>, 88 __numeric_traits_floating<_Value> >::__type 89 { }; 90 91_GLIBCXX_END_NAMESPACE 92 93#undef __glibcxx_signed 94#undef __glibcxx_min 95#undef __glibcxx_max 96#undef __glibcxx_digits 97 98#endif 99