boost/integer_traits.hpp

   1 /* boost integer_traits.hpp header file
   2  *
   3  * Copyright Jens Maurer 2000
   4  * Distributed under the Boost Software License, Version 1.0. (See
   5  * accompanying file LICENSE_1_0.txt or copy at
   6  * http://www.boost.org/LICENSE_1_0.txt)
   7  *
   8  * $Id$
   9  *
  10  * Idea by Beman Dawes, Ed Brey, Steve Cleary, and Nathan Myers
  11  */
  12
  13 //  See http://www.boost.org/libs/integer for documentation.
  14
  15
  16 #ifndef BOOST_INTEGER_TRAITS_HPP
  17 #define BOOST_INTEGER_TRAITS_HPP
  18
  19 #include <boost/config.hpp>
  20 #include <boost/limits.hpp>
  21
  22 // These are an implementation detail and not part of the interface
  23 #include <limits.h>
  24 // we need wchar.h for WCHAR_MAX/MIN but not all platforms provide it,
  25 // and some may have <wchar.h> but not <cwchar> ...
  26 #if !defined(BOOST_NO_INTRINSIC_WCHAR_T) && (!defined(BOOST_NO_CWCHAR) || defined(sun) || defined(__sun) || defined(__QNX__))
  27 #include <wchar.h>
  28 #endif
  29
  30 #include <boost/detail/extended_integer.hpp>  // for BOOST_HAS_XINT, etc.
  31
  32
  33 namespace boost {
  34 template<class T>
  35 class integer_traits : public std::numeric_limits<T>
  36 {
  37 public:
  38   BOOST_STATIC_CONSTANT(bool, is_integral = false);
  39 };
  40
  41 namespace detail {
  42 template<class T, T min_val, T max_val>
  43 class integer_traits_base
  44 {
  45 public:
  46   BOOST_STATIC_CONSTANT(bool, is_integral = true);
  47   BOOST_STATIC_CONSTANT(T, const_min = min_val);
  48   BOOST_STATIC_CONSTANT(T, const_max = max_val);
  49 };
  50
  51 #ifndef BOOST_NO_INCLASS_MEMBER_INITIALIZATION
  52 //  A definition is required even for integral static constants
  53 template<class T, T min_val, T max_val>
  54 const bool integer_traits_base<T, min_val, max_val>::is_integral;
  55
  56 template<class T, T min_val, T max_val>
  57 const T integer_traits_base<T, min_val, max_val>::const_min;
  58
  59 template<class T, T min_val, T max_val>
  60 const T integer_traits_base<T, min_val, max_val>::const_max;
  61 #endif
  62
  63 } // namespace detail
  64
  65 template<>
  66 class integer_traits<bool>
  67   : public std::numeric_limits<bool>,
  68     public detail::integer_traits_base<bool, false, true>
  69 { };
  70
  71 template<>
  72 class integer_traits<char>
  73   : public std::numeric_limits<char>,
  74     public detail::integer_traits_base<char, CHAR_MIN, CHAR_MAX>
  75 { };
  76
  77 template<>
  78 class integer_traits<signed char>
  79   : public std::numeric_limits<signed char>,
  80     public detail::integer_traits_base<signed char, SCHAR_MIN, SCHAR_MAX>
  81 { };
  82
  83 template<>
  84 class integer_traits<unsigned char>
  85   : public std::numeric_limits<unsigned char>,
  86     public detail::integer_traits_base<unsigned char, 0, UCHAR_MAX>
  87 { };
  88
  89 #ifndef BOOST_NO_INTRINSIC_WCHAR_T
  90 template<>
  91 class integer_traits<wchar_t>
  92   : public std::numeric_limits<wchar_t>,
  93     // Don't trust WCHAR_MIN and WCHAR_MAX with Mac OS X's native
  94     // library: they are wrong!
  95 #if defined(WCHAR_MIN) && defined(WCHAR_MAX) && !defined(__APPLE__)
  96     public detail::integer_traits_base<wchar_t, WCHAR_MIN, WCHAR_MAX>
  97 #elif defined(__BORLANDC__) || defined(__CYGWIN__) || defined(__MINGW32__) || (defined(__BEOS__) && defined(__GNUC__))
  98     // No WCHAR_MIN and WCHAR_MAX, whar_t is short and unsigned:
  99     public detail::integer_traits_base<wchar_t, 0, 0xffff>
 100 #elif (defined(__sgi) && (!defined(__SGI_STL_PORT) || __SGI_STL_PORT < 0x400))\
 101     || (defined __APPLE__)\
 102     || (defined(__OpenBSD__) && defined(__GNUC__))\
 103     || (defined(__NetBSD__) && defined(__GNUC__))\
 104     || (defined(__FreeBSD__) && defined(__GNUC__))\
 105     || (defined(__DragonFly__) && defined(__GNUC__))\
 106     || (defined(__hpux) && defined(__GNUC__) && (__GNUC__ == 3) && !defined(__SGI_STL_PORT))
 107     // No WCHAR_MIN and WCHAR_MAX, wchar_t has the same range as int.
 108     //  - SGI MIPSpro with native library
 109     //  - gcc 3.x on HP-UX
 110     //  - Mac OS X with native library
 111     //  - gcc on FreeBSD, OpenBSD and NetBSD
 112     public detail::integer_traits_base<wchar_t, INT_MIN, INT_MAX>
 113 #elif defined(__hpux) && defined(__GNUC__) && (__GNUC__ == 2) && !defined(__SGI_STL_PORT)
 114     // No WCHAR_MIN and WCHAR_MAX, wchar_t has the same range as unsigned int.
 115     //  - gcc 2.95.x on HP-UX
 116     // (also, std::numeric_limits<wchar_t> appears to return the wrong values).
 117     public detail::integer_traits_base<wchar_t, 0, UINT_MAX>
 118 #else
 119 #error No WCHAR_MIN and WCHAR_MAX present, please adjust integer_traits<> for your compiler.
 120 #endif
 121 { };
 122 #endif // BOOST_NO_INTRINSIC_WCHAR_T
 123
 124 template<>
 125 class integer_traits<short>
 126   : public std::numeric_limits<short>,
 127     public detail::integer_traits_base<short, SHRT_MIN, SHRT_MAX>
 128 { };
 129
 130 template<>
 131 class integer_traits<unsigned short>
 132   : public std::numeric_limits<unsigned short>,
 133     public detail::integer_traits_base<unsigned short, 0, USHRT_MAX>
 134 { };
 135
 136 template<>
 137 class integer_traits<int>
 138   : public std::numeric_limits<int>,
 139     public detail::integer_traits_base<int, INT_MIN, INT_MAX>
 140 { };
 141
 142 template<>
 143 class integer_traits<unsigned int>
 144   : public std::numeric_limits<unsigned int>,
 145     public detail::integer_traits_base<unsigned int, 0, UINT_MAX>
 146 { };
 147
 148 template<>
 149 class integer_traits<long>
 150   : public std::numeric_limits<long>,
 151     public detail::integer_traits_base<long, LONG_MIN, LONG_MAX>
 152 { };
 153
 154 template<>
 155 class integer_traits<unsigned long>
 156   : public std::numeric_limits<unsigned long>,
 157     public detail::integer_traits_base<unsigned long, 0, ULONG_MAX>
 158 { };
 159
 160 #if !defined(BOOST_NO_INTEGRAL_INT64_T) && !defined(BOOST_NO_INT64_T) && BOOST_HAS_XINT
 161 template<>
 162 class integer_traits< detail::xint_t >
 163   : public std::numeric_limits< detail::xint_t >,
 164     public detail::integer_traits_base< detail::xint_t, BOOST_XINT_MIN, BOOST_XINT_MAX >
 165 { };
 166
 167 template<>
 168 class integer_traits< detail::uxint_t >
 169   : public std::numeric_limits< detail::uxint_t >,
 170     public detail::integer_traits_base< detail::uxint_t, 0u, BOOST_UXINT_MAX >
 171 { };
 172 #endif
 173
 174 } // namespace boost
 175
 176 #endif /* BOOST_INTEGER_TRAITS_HPP */
 177
 178
 179