ceph/src/boost/boost/numeric/conversion/detail/old_numeric_cast.hpp

   1 //  boost cast.hpp header file  ----------------------------------------------//
   2
   3 //  (C) Copyright Kevlin Henney and Dave Abrahams 1999.
   4 //  Distributed under the Boost
   5 //  Software License, Version 1.0. (See accompanying file
   6 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7
   8 //  See http://www.boost.org/libs/conversion for Documentation.
   9
  10 //  Revision History
  11 //  02 Jun 14  Remove VC6 workarounds.
  12 //  16 Jul 11  Bugfixes for VC6.
  13 //  23 JUN 05  Code extracted from /boost/cast.hpp into this new header.
  14 //             Keeps this legacy version of numeric_cast<> for old compilers
  15 //             wich can't compile the new version in /boost/numeric/conversion/cast.hpp
  16 //             (Fernando Cacciola)
  17 //  02 Apr 01  Removed BOOST_NO_LIMITS workarounds and included
  18 //             <boost/limits.hpp> instead (the workaround did not
  19 //             actually compile when BOOST_NO_LIMITS was defined in
  20 //             any case, so we loose nothing). (John Maddock)
  21 //  21 Jan 01  Undid a bug I introduced yesterday. numeric_cast<> never
  22 //             worked with stock GCC; trying to get it to do that broke
  23 //             vc-stlport.
  24 //  20 Jan 01  Moved BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS to config.hpp.
  25 //             Removed unused BOOST_EXPLICIT_TARGET macro. Moved
  26 //             boost::detail::type to boost/type.hpp. Made it compile with
  27 //             stock gcc again (Dave Abrahams)
  28 //  29 Nov 00  Remove nested namespace cast, cleanup spacing before Formal
  29 //             Review (Beman Dawes)
  30 //  19 Oct 00  Fix numeric_cast for floating-point types (Dave Abrahams)
  31 //  15 Jul 00  Suppress numeric_cast warnings for GCC, Borland and MSVC
  32 //             (Dave Abrahams)
  33 //  30 Jun 00  More MSVC6 wordarounds.  See comments below.  (Dave Abrahams)
  34 //  28 Jun 00  Removed implicit_cast<>.  See comment below. (Beman Dawes)
  35 //  27 Jun 00  More MSVC6 workarounds
  36 //  15 Jun 00  Add workarounds for MSVC6
  37 //   2 Feb 00  Remove bad_numeric_cast ";" syntax error (Doncho Angelov)
  38 //  26 Jan 00  Add missing throw() to bad_numeric_cast::what(0 (Adam Levar)
  39 //  29 Dec 99  Change using declarations so usages in other namespaces work
  40 //             correctly (Dave Abrahams)
  41 //  23 Sep 99  Change polymorphic_downcast assert to also detect M.I. errors
  42 //             as suggested Darin Adler and improved by Valentin Bonnard.
  43 //   2 Sep 99  Remove controversial asserts, simplify, rename.
  44 //  30 Aug 99  Move to cast.hpp, replace value_cast with numeric_cast,
  45 //             place in nested namespace.
  46 //   3 Aug 99  Initial version
  47
  48 #ifndef BOOST_OLD_NUMERIC_CAST_HPP
  49 #define BOOST_OLD_NUMERIC_CAST_HPP
  50
  51 # include <boost/config.hpp>
  52 # include <cassert>
  53 # include <typeinfo>
  54 # include <boost/type.hpp>
  55 # include <boost/limits.hpp>
  56 # include <boost/numeric/conversion/converter_policies.hpp>
  57
  58 namespace boost
  59 {
  60   using numeric::bad_numeric_cast;
  61
  62 //  LEGACY numeric_cast [only for some old broken compilers] --------------------------------------//
  63
  64 //  Contributed by Kevlin Henney
  65
  66 //  numeric_cast  ------------------------------------------------------------//
  67
  68 #if !defined(BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS) || defined(BOOST_SGI_CPP_LIMITS)
  69
  70     namespace detail
  71     {
  72       template <class T>
  73       struct signed_numeric_limits : std::numeric_limits<T>
  74       {
  75              static inline T min BOOST_PREVENT_MACRO_SUBSTITUTION ()
  76          {
  77              return (std::numeric_limits<T>::min)() >= 0
  78                      // unary minus causes integral promotion, thus the static_cast<>
  79                      ? static_cast<T>(-(std::numeric_limits<T>::max)())
  80                      : (std::numeric_limits<T>::min)();
  81          };
  82       };
  83
  84       // Move to namespace boost in utility.hpp?
  85       template <class T, bool specialized>
  86       struct fixed_numeric_limits_base
  87           : public if_true< std::numeric_limits<T>::is_signed >
  88            ::BOOST_NESTED_TEMPLATE then< signed_numeric_limits<T>,
  89                             std::numeric_limits<T>
  90                    >::type
  91       {};
  92
  93       template <class T>
  94       struct fixed_numeric_limits
  95           : fixed_numeric_limits_base<T,(std::numeric_limits<T>::is_specialized)>
  96       {};
  97
  98 # ifdef BOOST_HAS_LONG_LONG
  99       // cover implementations which supply no specialization for long
 100       // long / unsigned long long. Not intended to be full
 101       // numeric_limits replacements, but good enough for numeric_cast<>
 102       template <>
 103       struct fixed_numeric_limits_base< ::boost::long_long_type, false>
 104       {
 105           BOOST_STATIC_CONSTANT(bool, is_specialized = true);
 106           BOOST_STATIC_CONSTANT(bool, is_signed = true);
 107           static  ::boost::long_long_type max BOOST_PREVENT_MACRO_SUBSTITUTION ()
 108           {
 109 #  ifdef LONGLONG_MAX
 110               return LONGLONG_MAX;
 111 #  else
 112               return 9223372036854775807LL; // hope this is portable
 113 #  endif
 114           }
 115
 116           static  ::boost::long_long_type min BOOST_PREVENT_MACRO_SUBSTITUTION ()
 117           {
 118 #  ifdef LONGLONG_MIN
 119               return LONGLONG_MIN;
 120 #  else
 121                return -( 9223372036854775807LL )-1; // hope this is portable
 122 #  endif
 123           }
 124       };
 125
 126       template <>
 127       struct fixed_numeric_limits_base< ::boost::ulong_long_type, false>
 128       {
 129           BOOST_STATIC_CONSTANT(bool, is_specialized = true);
 130           BOOST_STATIC_CONSTANT(bool, is_signed = false);
 131           static  ::boost::ulong_long_type max BOOST_PREVENT_MACRO_SUBSTITUTION ()
 132           {
 133 #  ifdef ULONGLONG_MAX
 134               return ULONGLONG_MAX;
 135 #  else
 136               return 0xffffffffffffffffULL; // hope this is portable
 137 #  endif
 138           }
 139
 140           static  ::boost::ulong_long_type min BOOST_PREVENT_MACRO_SUBSTITUTION () { return 0; }
 141       };
 142 # endif
 143     } // namespace detail
 144
 145 // less_than_type_min -
 146   //    x_is_signed should be numeric_limits<X>::is_signed
 147   //    y_is_signed should be numeric_limits<Y>::is_signed
 148   //    y_min should be numeric_limits<Y>::min()
 149   //
 150   //    check(x, y_min) returns true iff x < y_min without invoking comparisons
 151   //    between signed and unsigned values.
 152   //
 153   //    "poor man's partial specialization" is in use here.
 154     template <bool x_is_signed, bool y_is_signed>
 155     struct less_than_type_min
 156     {
 157         template <class X, class Y>
 158         static bool check(X x, Y y_min)
 159             { return x < y_min; }
 160     };
 161
 162     template <>
 163     struct less_than_type_min<false, true>
 164     {
 165         template <class X, class Y>
 166         static bool check(X, Y)
 167             { return false; }
 168     };
 169
 170     template <>
 171     struct less_than_type_min<true, false>
 172     {
 173         template <class X, class Y>
 174         static bool check(X x, Y)
 175             { return x < 0; }
 176     };
 177
 178   // greater_than_type_max -
 179   //    same_sign should be:
 180   //            numeric_limits<X>::is_signed == numeric_limits<Y>::is_signed
 181   //    y_max should be numeric_limits<Y>::max()
 182   //
 183   //    check(x, y_max) returns true iff x > y_max without invoking comparisons
 184   //    between signed and unsigned values.
 185   //
 186   //    "poor man's partial specialization" is in use here.
 187     template <bool same_sign, bool x_is_signed>
 188     struct greater_than_type_max;
 189
 190     template<>
 191     struct greater_than_type_max<true, true>
 192     {
 193         template <class X, class Y>
 194         static inline bool check(X x, Y y_max)
 195             { return x > y_max; }
 196     };
 197
 198     template <>
 199     struct greater_than_type_max<false, true>
 200     {
 201         // What does the standard say about this? I think it's right, and it
 202         // will work with every compiler I know of.
 203         template <class X, class Y>
 204         static inline bool check(X x, Y)
 205             { return x >= 0 && static_cast<X>(static_cast<Y>(x)) != x; }
 206     };
 207
 208     template<>
 209     struct greater_than_type_max<true, false>
 210     {
 211         template <class X, class Y>
 212         static inline bool check(X x, Y y_max)
 213             { return x > y_max; }
 214     };
 215
 216     template <>
 217     struct greater_than_type_max<false, false>
 218     {
 219         // What does the standard say about this? I think it's right, and it
 220         // will work with every compiler I know of.
 221         template <class X, class Y>
 222         static inline bool check(X x, Y)
 223             { return static_cast<X>(static_cast<Y>(x)) != x; }
 224     };
 225
 226 #else // use #pragma hacks if available
 227
 228   namespace detail
 229   {
 230 # if BOOST_MSVC
 231 #  pragma warning(push)
 232 #  pragma warning(disable : 4018)
 233 #  pragma warning(disable : 4146)
 234 #elif defined(BOOST_BORLANDC)
 235 #  pragma option push -w-8041
 236 # endif
 237
 238        // Move to namespace boost in utility.hpp?
 239        template <class T>
 240        struct fixed_numeric_limits : public std::numeric_limits<T>
 241        {
 242            static inline T min BOOST_PREVENT_MACRO_SUBSTITUTION ()
 243            {
 244                return std::numeric_limits<T>::is_signed && (std::numeric_limits<T>::min)() >= 0
 245                    ? T(-(std::numeric_limits<T>::max)()) : (std::numeric_limits<T>::min)();
 246            }
 247        };
 248
 249 # if BOOST_MSVC
 250 #  pragma warning(pop)
 251 #elif defined(BOOST_BORLANDC)
 252 #  pragma option pop
 253 # endif
 254   } // namespace detail
 255
 256 #endif
 257
 258     template<typename Target, typename Source>
 259     inline Target numeric_cast(Source arg)
 260     {
 261         // typedefs abbreviating respective trait classes
 262         typedef detail::fixed_numeric_limits<Source> arg_traits;
 263         typedef detail::fixed_numeric_limits<Target> result_traits;
 264
 265 #if defined(BOOST_STRICT_CONFIG) \
 266     || (!defined(__HP_aCC) || __HP_aCC > 33900) \
 267          && (!defined(BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS) \
 268              || defined(BOOST_SGI_CPP_LIMITS))
 269         // typedefs that act as compile time assertions
 270         // (to be replaced by boost compile time assertions
 271         // as and when they become available and are stable)
 272         typedef bool argument_must_be_numeric[arg_traits::is_specialized];
 273         typedef bool result_must_be_numeric[result_traits::is_specialized];
 274
 275         const bool arg_is_signed = arg_traits::is_signed;
 276         const bool result_is_signed = result_traits::is_signed;
 277         const bool same_sign = arg_is_signed == result_is_signed;
 278
 279         if (less_than_type_min<arg_is_signed, result_is_signed>::check(arg, (result_traits::min)())
 280             || greater_than_type_max<same_sign, arg_is_signed>::check(arg, (result_traits::max)())
 281             )
 282
 283 #else // We need to use #pragma hacks if available
 284
 285 # if BOOST_MSVC
 286 #  pragma warning(push)
 287 #  pragma warning(disable : 4018)
 288 #elif defined(BOOST_BORLANDC)
 289 #pragma option push -w-8012
 290 # endif
 291         if ((arg < 0 && !result_traits::is_signed)  // loss of negative range
 292              || (arg_traits::is_signed && arg < (result_traits::min)())  // underflow
 293              || arg > (result_traits::max)())            // overflow
 294 # if BOOST_MSVC
 295 #  pragma warning(pop)
 296 #elif defined(BOOST_BORLANDC)
 297 #pragma option pop
 298 # endif
 299 #endif
 300         {
 301             throw bad_numeric_cast();
 302         }
 303         return static_cast<Target>(arg);
 304     } // numeric_cast
 305
 306 } // namespace boost
 307
 308 #endif  // BOOST_OLD_NUMERIC_CAST_HPP