sl@0: // Copyright David Abrahams 2002.
sl@0: // Distributed under the Boost Software License, Version 1.0. (See
sl@0: // accompanying file LICENSE_1_0.txt or copy at
sl@0: // http://www.boost.org/LICENSE_1_0.txt)
sl@0: #ifndef CAST_DWA200269_HPP
sl@0: # define CAST_DWA200269_HPP
sl@0: 
sl@0: # include <boost/python/detail/prefix.hpp>
sl@0: 
sl@0: # include <boost/type_traits/same_traits.hpp>
sl@0: # include <boost/type_traits/cv_traits.hpp>
sl@0: # include <boost/type.hpp>
sl@0: # include <boost/python/base_type_traits.hpp>
sl@0: # include <boost/python/detail/convertible.hpp>
sl@0: 
sl@0: namespace boost { namespace python { 
sl@0: 
sl@0: namespace detail
sl@0: {
sl@0:   template <class Source, class Target> inline Target* upcast_impl(Source*, Target*);
sl@0:   
sl@0:   template <class Source, class Target>
sl@0:   inline Target* upcast(Source* p, yes_convertible, no_convertible, Target*)
sl@0:   {
sl@0:       return p;
sl@0:   }
sl@0: 
sl@0:   template <class Source, class Target>
sl@0:   inline Target* upcast(Source* p, no_convertible, no_convertible, Target*)
sl@0:   {
sl@0:       typedef typename base_type_traits<Source>::type base;
sl@0:       
sl@0:       return detail::upcast_impl((base*)p, (Target*)0);
sl@0:   }
sl@0: 
sl@0:   template <bool is_same = true>
sl@0:   struct upcaster
sl@0:   {
sl@0:       template <class T>
sl@0:       static inline T* execute(T* x, T*) { return x; }
sl@0:   };
sl@0:   
sl@0:   template <>
sl@0:   struct upcaster<false>
sl@0:   {
sl@0:       template <class Source, class Target>
sl@0:       static inline Target* execute(Source* x, Target*)
sl@0:       {
sl@0:           return detail::upcast(
sl@0:               x, detail::convertible<Target*>::check(x)
sl@0:               , detail::convertible<Source*>::check((Target*)0)
sl@0:               , (Target*)0);
sl@0:       }
sl@0:   };
sl@0: 
sl@0: 
sl@0:   template <class Target, class Source>
sl@0:   inline Target* downcast(Source* p, yes_convertible)
sl@0:   {
sl@0:       return static_cast<Target*>(p);
sl@0:   }
sl@0: 
sl@0:   template <class Target, class Source>
sl@0:   inline Target* downcast(Source* p, no_convertible, boost::type<Target>* = 0)
sl@0:   {
sl@0:       typedef typename base_type_traits<Source>::type base;
sl@0:       return (Target*)detail::downcast<base>(p, convertible<Source*>::check((base*)0));
sl@0:   }
sl@0: 
sl@0:   template <class T>
sl@0:   inline void assert_castable(boost::type<T>* = 0)
sl@0:   {
sl@0:       typedef char must_be_a_complete_type[sizeof(T)];
sl@0:   }
sl@0: 
sl@0:   template <class Source, class Target>
sl@0:   inline Target* upcast_impl(Source* x, Target*)
sl@0:   {
sl@0:       typedef typename add_cv<Source>::type src_t;
sl@0:       typedef typename add_cv<Target>::type target_t;
sl@0:       bool const same = is_same<src_t,target_t>::value;
sl@0:       
sl@0:       return detail::upcaster<same>::execute(x, (Target*)0);
sl@0:   }
sl@0: }
sl@0: 
sl@0: template <class Target, class Source>
sl@0: inline Target* upcast(Source* x, Target* = 0)
sl@0: {
sl@0:     detail::assert_castable<Source>();
sl@0:     detail::assert_castable<Target>();
sl@0:     return detail::upcast_impl(x, (Target*)0);
sl@0:     
sl@0: }
sl@0: 
sl@0: template <class Target, class Source>
sl@0: inline Target* downcast(Source* x, Target* = 0)
sl@0: {
sl@0:     detail::assert_castable<Source>();
sl@0:     detail::assert_castable<Target>();
sl@0:     return detail::downcast<Target>(x, detail::convertible<Source*>::check((Target*)0));
sl@0: }
sl@0: 
sl@0: }} // namespace boost::python
sl@0: 
sl@0: #endif // CAST_DWA200269_HPP