//  boost cast.hpp header file  ----------------------------------------------//

 //  (C) Copyright Kevlin Henney and Dave Abrahams 1999.

 //  Distributed under the Boost

 //  Software License, Version 1.0. (See accompanying file

 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

 //  See http://www.boost.org/libs/conversion for Documentation.

 //  Revision History

 //  23 JUn 05  numeric_cast removed and redirected to the new verion (Fernando Cacciola)

 //  02 Apr 01  Removed BOOST_NO_LIMITS workarounds and included

 //             <boost/limits.hpp> instead (the workaround did not

 //             actually compile when BOOST_NO_LIMITS was defined in

 //             any case, so we loose nothing). (John Maddock)

 //  21 Jan 01  Undid a bug I introduced yesterday. numeric_cast<> never

 //             worked with stock GCC; trying to get it to do that broke

 //             vc-stlport.

 //  20 Jan 01  Moved BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS to config.hpp.

 //             Removed unused BOOST_EXPLICIT_TARGET macro. Moved

 //             boost::detail::type to boost/type.hpp. Made it compile with

 //             stock gcc again (Dave Abrahams)

 //  29 Nov 00  Remove nested namespace cast, cleanup spacing before Formal

 //             Review (Beman Dawes)

 //  19 Oct 00  Fix numeric_cast for floating-point types (Dave Abrahams)

 //  15 Jul 00  Suppress numeric_cast warnings for GCC, Borland and MSVC

 //             (Dave Abrahams)

 //  30 Jun 00  More MSVC6 wordarounds.  See comments below.  (Dave Abrahams)

 //  28 Jun 00  Removed implicit_cast<>.  See comment below. (Beman Dawes)

 //  27 Jun 00  More MSVC6 workarounds

 //  15 Jun 00  Add workarounds for MSVC6

 //   2 Feb 00  Remove bad_numeric_cast ";" syntax error (Doncho Angelov)

 //  26 Jan 00  Add missing throw() to bad_numeric_cast::what(0 (Adam Levar)

 //  29 Dec 99  Change using declarations so usages in other namespaces work

 //             correctly (Dave Abrahams)

 //  23 Sep 99  Change polymorphic_downcast assert to also detect M.I. errors

 //             as suggested Darin Adler and improved by Valentin Bonnard.

 //   2 Sep 99  Remove controversial asserts, simplify, rename.

 //  30 Aug 99  Move to cast.hpp, replace value_cast with numeric_cast,

 //             place in nested namespace.

 //   3 Aug 99  Initial version

 #ifndef BOOST_CAST_HPP

 #define BOOST_CAST_HPP

 # include <boost/config.hpp>

 # include <boost/assert.hpp>

 # include <typeinfo>

 # include <boost/type.hpp>

 # include <boost/limits.hpp>

 # include <boost/detail/select_type.hpp>

 //  It has been demonstrated numerous times that MSVC 6.0 fails silently at link

 //  time if you use a template function which has template parameters that don't

 //  appear in the function's argument list.

 //

 //  TODO: Add this to config.hpp?

 # if defined(BOOST_MSVC) && BOOST_MSVC < 1300

 #  define BOOST_EXPLICIT_DEFAULT_TARGET , ::boost::type<Target>* = 0

 # else

 #  define BOOST_EXPLICIT_DEFAULT_TARGET

 # endif

 namespace boost

 {

 //  See the documentation for descriptions of how to choose between

 //  static_cast<>, dynamic_cast<>, polymorphic_cast<> and polymorphic_downcast<>

 //  polymorphic_cast  --------------------------------------------------------//

     //  Runtime checked polymorphic downcasts and crosscasts.

     //  Suggested in The C++ Programming Language, 3rd Ed, Bjarne Stroustrup,

     //  section 15.8 exercise 1, page 425.

     template <class Target, class Source>

     inline Target polymorphic_cast(Source* x BOOST_EXPLICIT_DEFAULT_TARGET)

     {

         Target tmp = dynamic_cast<Target>(x);

         if ( tmp == 0 ) throw std::bad_cast();

         return tmp;

     }

 //  polymorphic_downcast  ----------------------------------------------------//

     //  BOOST_ASSERT() checked polymorphic downcast.  Crosscasts prohibited.

     //  WARNING: Because this cast uses BOOST_ASSERT(), it violates

     //  the One Definition Rule if used in multiple translation units

     //  where BOOST_DISABLE_ASSERTS, BOOST_ENABLE_ASSERT_HANDLER

     //  NDEBUG are defined inconsistently.

     //  Contributed by Dave Abrahams

     template <class Target, class Source>

     inline Target polymorphic_downcast(Source* x BOOST_EXPLICIT_DEFAULT_TARGET)

     {

         BOOST_ASSERT( dynamic_cast<Target>(x) == x );  // detect logic error

         return static_cast<Target>(x);

     }

 #  undef BOOST_EXPLICIT_DEFAULT_TARGET

 } // namespace boost

 # include <boost/numeric/conversion/cast.hpp>

 #endif  // BOOST_CAST_HPP