Chris@16: //  boost cast.hpp header file  ----------------------------------------------//
Chris@16: 
Chris@16: //  (C) Copyright Kevlin Henney and Dave Abrahams 1999.
Chris@16: //  Distributed under the Boost
Chris@16: //  Software License, Version 1.0. (See accompanying file
Chris@16: //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: //  See http://www.boost.org/libs/conversion for Documentation.
Chris@16: 
Chris@16: //  Revision History
Chris@16: //  23 JUN 05  Code extracted from /boost/cast.hpp into this new header.
Chris@16: //             Keeps this legacy version of numeric_cast<> for old compilers
Chris@16: //             wich can't compile the new version in /boost/numeric/conversion/cast.hpp
Chris@16: //             (Fernando Cacciola)
Chris@16: //  02 Apr 01  Removed BOOST_NO_LIMITS workarounds and included
Chris@16: //             <boost/limits.hpp> instead (the workaround did not
Chris@16: //             actually compile when BOOST_NO_LIMITS was defined in
Chris@16: //             any case, so we loose nothing). (John Maddock)
Chris@16: //  21 Jan 01  Undid a bug I introduced yesterday. numeric_cast<> never
Chris@16: //             worked with stock GCC; trying to get it to do that broke
Chris@16: //             vc-stlport.
Chris@16: //  20 Jan 01  Moved BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS to config.hpp.
Chris@16: //             Removed unused BOOST_EXPLICIT_TARGET macro. Moved
Chris@16: //             boost::detail::type to boost/type.hpp. Made it compile with
Chris@16: //             stock gcc again (Dave Abrahams)
Chris@16: //  29 Nov 00  Remove nested namespace cast, cleanup spacing before Formal
Chris@16: //             Review (Beman Dawes)
Chris@16: //  19 Oct 00  Fix numeric_cast for floating-point types (Dave Abrahams)
Chris@16: //  15 Jul 00  Suppress numeric_cast warnings for GCC, Borland and MSVC
Chris@16: //             (Dave Abrahams)
Chris@16: //  30 Jun 00  More MSVC6 wordarounds.  See comments below.  (Dave Abrahams)
Chris@16: //  28 Jun 00  Removed implicit_cast<>.  See comment below. (Beman Dawes)
Chris@16: //  27 Jun 00  More MSVC6 workarounds
Chris@16: //  15 Jun 00  Add workarounds for MSVC6
Chris@16: //   2 Feb 00  Remove bad_numeric_cast ";" syntax error (Doncho Angelov)
Chris@16: //  26 Jan 00  Add missing throw() to bad_numeric_cast::what(0 (Adam Levar)
Chris@16: //  29 Dec 99  Change using declarations so usages in other namespaces work
Chris@16: //             correctly (Dave Abrahams)
Chris@16: //  23 Sep 99  Change polymorphic_downcast assert to also detect M.I. errors
Chris@16: //             as suggested Darin Adler and improved by Valentin Bonnard.
Chris@16: //   2 Sep 99  Remove controversial asserts, simplify, rename.
Chris@16: //  30 Aug 99  Move to cast.hpp, replace value_cast with numeric_cast,
Chris@16: //             place in nested namespace.
Chris@16: //   3 Aug 99  Initial version
Chris@16: 
Chris@16: #ifndef BOOST_OLD_NUMERIC_CAST_HPP
Chris@16: #define BOOST_OLD_NUMERIC_CAST_HPP
Chris@16: 
Chris@16: # include <boost/config.hpp>
Chris@16: # include <cassert>
Chris@16: # include <typeinfo>
Chris@16: # include <boost/type.hpp>
Chris@16: # include <boost/limits.hpp>
Chris@16: # include <boost/numeric/conversion/converter_policies.hpp>
Chris@16: 
Chris@16: //  It has been demonstrated numerous times that MSVC 6.0 fails silently at link
Chris@16: //  time if you use a template function which has template parameters that don't
Chris@16: //  appear in the function's argument list.
Chris@16: //
Chris@16: //  TODO: Add this to config.hpp?
Chris@16: //  FLC: This macro is repeated in boost/cast.hpp but only locally (is undefined at the bottom)
Chris@16: //       so is OK to reproduce it here.
Chris@16: # if defined(BOOST_MSVC) && BOOST_MSVC < 1300
Chris@16: #  define BOOST_EXPLICIT_DEFAULT_TARGET , ::boost::type<Target>* = 0
Chris@16: # else
Chris@16: #  define BOOST_EXPLICIT_DEFAULT_TARGET
Chris@16: # endif
Chris@16: 
Chris@16: namespace boost
Chris@16: {
Chris@16:   using numeric::bad_numeric_cast;
Chris@16: 
Chris@16: //  LEGACY numeric_cast [only for some old broken compilers] --------------------------------------//
Chris@16: 
Chris@16: //  Contributed by Kevlin Henney
Chris@16: 
Chris@16: //  numeric_cast  ------------------------------------------------------------//
Chris@16: 
Chris@16: #if !defined(BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS) || defined(BOOST_SGI_CPP_LIMITS)
Chris@16: 
Chris@16:     namespace detail
Chris@16:     {
Chris@16:       template <class T>
Chris@16:       struct signed_numeric_limits : std::numeric_limits<T>
Chris@16:       {
Chris@16:              static inline T min BOOST_PREVENT_MACRO_SUBSTITUTION ()
Chris@16:          {
Chris@16:              return (std::numeric_limits<T>::min)() >= 0
Chris@16:                      // unary minus causes integral promotion, thus the static_cast<>
Chris@16:                      ? static_cast<T>(-(std::numeric_limits<T>::max)())
Chris@16:                      : (std::numeric_limits<T>::min)();
Chris@16:          };
Chris@16:       };
Chris@16: 
Chris@16:       // Move to namespace boost in utility.hpp?
Chris@16:       template <class T, bool specialized>
Chris@16:       struct fixed_numeric_limits_base
Chris@16:           : public if_true< std::numeric_limits<T>::is_signed >
Chris@16:            ::BOOST_NESTED_TEMPLATE then< signed_numeric_limits<T>,
Chris@16:                             std::numeric_limits<T>
Chris@16:                    >::type
Chris@16:       {};
Chris@16: 
Chris@16:       template <class T>
Chris@16:       struct fixed_numeric_limits
Chris@16:           : fixed_numeric_limits_base<T,(std::numeric_limits<T>::is_specialized)>
Chris@16:       {};
Chris@16: 
Chris@16: # ifdef BOOST_HAS_LONG_LONG
Chris@16:       // cover implementations which supply no specialization for long
Chris@16:       // long / unsigned long long. Not intended to be full
Chris@16:       // numeric_limits replacements, but good enough for numeric_cast<>
Chris@16:       template <>
Chris@16:       struct fixed_numeric_limits_base< ::boost::long_long_type, false>
Chris@16:       {
Chris@16:           BOOST_STATIC_CONSTANT(bool, is_specialized = true);
Chris@16:           BOOST_STATIC_CONSTANT(bool, is_signed = true);
Chris@16:           static  ::boost::long_long_type max BOOST_PREVENT_MACRO_SUBSTITUTION ()
Chris@16:           {
Chris@16: #  ifdef LONGLONG_MAX
Chris@16:               return LONGLONG_MAX;
Chris@16: #  else
Chris@16:               return 9223372036854775807LL; // hope this is portable
Chris@16: #  endif
Chris@16:           }
Chris@16: 
Chris@16:           static  ::boost::long_long_type min BOOST_PREVENT_MACRO_SUBSTITUTION ()
Chris@16:           {
Chris@16: #  ifdef LONGLONG_MIN
Chris@16:               return LONGLONG_MIN;
Chris@16: #  else
Chris@16:                return -( 9223372036854775807LL )-1; // hope this is portable
Chris@16: #  endif
Chris@16:           }
Chris@16:       };
Chris@16: 
Chris@16:       template <>
Chris@16:       struct fixed_numeric_limits_base< ::boost::ulong_long_type, false>
Chris@16:       {
Chris@16:           BOOST_STATIC_CONSTANT(bool, is_specialized = true);
Chris@16:           BOOST_STATIC_CONSTANT(bool, is_signed = false);
Chris@16:           static  ::boost::ulong_long_type max BOOST_PREVENT_MACRO_SUBSTITUTION ()
Chris@16:           {
Chris@16: #  ifdef ULONGLONG_MAX
Chris@16:               return ULONGLONG_MAX;
Chris@16: #  else
Chris@16:               return 0xffffffffffffffffULL; // hope this is portable
Chris@16: #  endif
Chris@16:           }
Chris@16: 
Chris@16:           static  ::boost::ulong_long_type min BOOST_PREVENT_MACRO_SUBSTITUTION () { return 0; }
Chris@16:       };
Chris@16: # endif
Chris@16:     } // namespace detail
Chris@16: 
Chris@16: // less_than_type_min -
Chris@16:   //    x_is_signed should be numeric_limits<X>::is_signed
Chris@16:   //    y_is_signed should be numeric_limits<Y>::is_signed
Chris@16:   //    y_min should be numeric_limits<Y>::min()
Chris@16:   //
Chris@16:   //    check(x, y_min) returns true iff x < y_min without invoking comparisons
Chris@16:   //    between signed and unsigned values.
Chris@16:   //
Chris@16:   //    "poor man's partial specialization" is in use here.
Chris@16:     template <bool x_is_signed, bool y_is_signed>
Chris@16:     struct less_than_type_min
Chris@16:     {
Chris@16:         template <class X, class Y>
Chris@16:         static bool check(X x, Y y_min)
Chris@16:             { return x < y_min; }
Chris@16:     };
Chris@16: 
Chris@16:     template <>
Chris@16:     struct less_than_type_min<false, true>
Chris@16:     {
Chris@16:         template <class X, class Y>
Chris@16:         static bool check(X, Y)
Chris@16:             { return false; }
Chris@16:     };
Chris@16: 
Chris@16:     template <>
Chris@16:     struct less_than_type_min<true, false>
Chris@16:     {
Chris@16:         template <class X, class Y>
Chris@16:         static bool check(X x, Y)
Chris@16:             { return x < 0; }
Chris@16:     };
Chris@16: 
Chris@16:   // greater_than_type_max -
Chris@16:   //    same_sign should be:
Chris@16:   //            numeric_limits<X>::is_signed == numeric_limits<Y>::is_signed
Chris@16:   //    y_max should be numeric_limits<Y>::max()
Chris@16:   //
Chris@16:   //    check(x, y_max) returns true iff x > y_max without invoking comparisons
Chris@16:   //    between signed and unsigned values.
Chris@16:   //
Chris@16:   //    "poor man's partial specialization" is in use here.
Chris@16:     template <bool same_sign, bool x_is_signed>
Chris@16:     struct greater_than_type_max;
Chris@16: 
Chris@16:     template<>
Chris@16:     struct greater_than_type_max<true, true>
Chris@16:     {
Chris@16:         template <class X, class Y>
Chris@16:         static inline bool check(X x, Y y_max)
Chris@16:             { return x > y_max; }
Chris@16:     };
Chris@16: 
Chris@16:     template <>
Chris@16:     struct greater_than_type_max<false, true>
Chris@16:     {
Chris@16:         // What does the standard say about this? I think it's right, and it
Chris@16:         // will work with every compiler I know of.
Chris@16:         template <class X, class Y>
Chris@16:         static inline bool check(X x, Y)
Chris@16:             { return x >= 0 && static_cast<X>(static_cast<Y>(x)) != x; }
Chris@16: 
Chris@16: # if defined(BOOST_MSVC) && BOOST_MSVC < 1300
Chris@16:         // MSVC6 can't static_cast  unsigned __int64 -> floating types
Chris@16: #  define BOOST_UINT64_CAST(src_type)                                   \
Chris@16:         static inline bool check(src_type x, unsigned __int64)          \
Chris@16:         {                                                               \
Chris@16:             if (x < 0) return false;                                    \
Chris@16:             unsigned __int64 y = static_cast<unsigned __int64>(x);      \
Chris@16:             bool odd = y & 0x1;                                         \
Chris@16:             __int64 div2 = static_cast<__int64>(y >> 1);                \
Chris@16:             return ((static_cast<src_type>(div2) * 2.0) + odd) != x;    \
Chris@16:         }
Chris@16: 
Chris@16:         BOOST_UINT64_CAST(long double);
Chris@16:         BOOST_UINT64_CAST(double);
Chris@16:         BOOST_UINT64_CAST(float);
Chris@16: #  undef BOOST_UINT64_CAST
Chris@16: # endif
Chris@16:     };
Chris@16: 
Chris@16:     template<>
Chris@16:     struct greater_than_type_max<true, false>
Chris@16:     {
Chris@16:         template <class X, class Y>
Chris@16:         static inline bool check(X x, Y y_max)
Chris@16:             { return x > y_max; }
Chris@16:     };
Chris@16: 
Chris@16:     template <>
Chris@16:     struct greater_than_type_max<false, false>
Chris@16:     {
Chris@16:         // What does the standard say about this? I think it's right, and it
Chris@16:         // will work with every compiler I know of.
Chris@16:         template <class X, class Y>
Chris@16:         static inline bool check(X x, Y)
Chris@16:             { return static_cast<X>(static_cast<Y>(x)) != x; }
Chris@16:     };
Chris@16: 
Chris@16: #else // use #pragma hacks if available
Chris@16: 
Chris@16:   namespace detail
Chris@16:   {
Chris@16: # if BOOST_MSVC
Chris@16: #  pragma warning(push)
Chris@16: #  pragma warning(disable : 4018)
Chris@16: #  pragma warning(disable : 4146)
Chris@16: #elif defined(__BORLANDC__)
Chris@16: #  pragma option push -w-8041
Chris@16: # endif
Chris@16: 
Chris@16:        // Move to namespace boost in utility.hpp?
Chris@16:        template <class T>
Chris@16:        struct fixed_numeric_limits : public std::numeric_limits<T>
Chris@16:        {
Chris@16:            static inline T min BOOST_PREVENT_MACRO_SUBSTITUTION ()
Chris@16:            {
Chris@16:                return std::numeric_limits<T>::is_signed && (std::numeric_limits<T>::min)() >= 0
Chris@16:                    ? T(-(std::numeric_limits<T>::max)()) : (std::numeric_limits<T>::min)();
Chris@16:            }
Chris@16:        };
Chris@16: 
Chris@16: # if BOOST_MSVC
Chris@16: #  pragma warning(pop)
Chris@16: #elif defined(__BORLANDC__)
Chris@16: #  pragma option pop
Chris@16: # endif
Chris@16:   } // namespace detail
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16:     template<typename Target, typename Source>
Chris@16:     inline Target numeric_cast(Source arg BOOST_EXPLICIT_DEFAULT_TARGET)
Chris@16:     {
Chris@16:         // typedefs abbreviating respective trait classes
Chris@16:         typedef detail::fixed_numeric_limits<Source> arg_traits;
Chris@16:         typedef detail::fixed_numeric_limits<Target> result_traits;
Chris@16: 
Chris@16: #if defined(BOOST_STRICT_CONFIG) \
Chris@16:     || (!defined(__HP_aCC) || __HP_aCC > 33900) \
Chris@16:          && (!defined(BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS) \
Chris@16:              || defined(BOOST_SGI_CPP_LIMITS))
Chris@16:         // typedefs that act as compile time assertions
Chris@16:         // (to be replaced by boost compile time assertions
Chris@16:         // as and when they become available and are stable)
Chris@16:         typedef bool argument_must_be_numeric[arg_traits::is_specialized];
Chris@16:         typedef bool result_must_be_numeric[result_traits::is_specialized];
Chris@16: 
Chris@16:         const bool arg_is_signed = arg_traits::is_signed;
Chris@16:         const bool result_is_signed = result_traits::is_signed;
Chris@16:         const bool same_sign = arg_is_signed == result_is_signed;
Chris@16: 
Chris@16:         if (less_than_type_min<arg_is_signed, result_is_signed>::check(arg, (result_traits::min)())
Chris@16:             || greater_than_type_max<same_sign, arg_is_signed>::check(arg, (result_traits::max)())
Chris@16:             )
Chris@16: 
Chris@16: #else // We need to use #pragma hacks if available
Chris@16: 
Chris@16: # if BOOST_MSVC
Chris@16: #  pragma warning(push)
Chris@16: #  pragma warning(disable : 4018)
Chris@16: #elif defined(__BORLANDC__)
Chris@16: #pragma option push -w-8012
Chris@16: # endif
Chris@16:         if ((arg < 0 && !result_traits::is_signed)  // loss of negative range
Chris@16:              || (arg_traits::is_signed && arg < (result_traits::min)())  // underflow
Chris@16:              || arg > (result_traits::max)())            // overflow
Chris@16: # if BOOST_MSVC
Chris@16: #  pragma warning(pop)
Chris@16: #elif defined(__BORLANDC__)
Chris@16: #pragma option pop
Chris@16: # endif
Chris@16: #endif
Chris@16:         {
Chris@16:             throw bad_numeric_cast();
Chris@16:         }
Chris@16:         return static_cast<Target>(arg);
Chris@16:     } // numeric_cast
Chris@16: 
Chris@16: #  undef BOOST_EXPLICIT_DEFAULT_TARGET
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif  // BOOST_OLD_NUMERIC_CAST_HPP