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// Copyright David Abrahams 2002.
// 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)
#ifndef CAST_DWA200269_HPP
# define CAST_DWA200269_HPP
# include <boost/python/detail/prefix.hpp>
# include <boost/python/detail/type_traits.hpp>
# include <boost/type.hpp>
# include <boost/python/base_type_traits.hpp>
# include <boost/python/detail/convertible.hpp>
namespace boost { namespace python {
namespace detail
{
template <class Source, class Target> inline Target* upcast_impl(Source*, Target*);
template <class Source, class Target>
inline Target* upcast(Source* p, yes_convertible, no_convertible, Target*)
{
return p;
}
template <class Source, class Target>
inline Target* upcast(Source* p, no_convertible, no_convertible, Target*)
{
typedef typename base_type_traits<Source>::type base;
return detail::upcast_impl((base*)p, (Target*)0);
}
template <bool is_same = true>
struct upcaster
{
template <class T>
static inline T* execute(T* x, T*) { return x; }
};
template <>
struct upcaster<false>
{
template <class Source, class Target>
static inline Target* execute(Source* x, Target*)
{
return detail::upcast(
x, detail::convertible<Target*>::check(x)
, detail::convertible<Source*>::check((Target*)0)
, (Target*)0);
}
};
template <class Target, class Source>
inline Target* downcast(Source* p, yes_convertible)
{
return static_cast<Target*>(p);
}
template <class Target, class Source>
inline Target* downcast(Source* p, no_convertible, boost::type<Target>* = 0)
{
typedef typename base_type_traits<Source>::type base;
return (Target*)detail::downcast<base>(p, convertible<Source*>::check((base*)0));
}
template <class T>
inline void assert_castable(boost::type<T>* = 0)
{
typedef char must_be_a_complete_type[sizeof(T)] BOOST_ATTRIBUTE_UNUSED;
}
template <class Source, class Target>
inline Target* upcast_impl(Source* x, Target*)
{
typedef typename detail::add_cv<Source>::type src_t;
typedef typename detail::add_cv<Target>::type target_t;
bool const same = detail::is_same<src_t,target_t>::value;
return detail::upcaster<same>::execute(x, (Target*)0);
}
}
template <class Target, class Source>
inline Target* upcast(Source* x, Target* = 0)
{
detail::assert_castable<Source>();
detail::assert_castable<Target>();
return detail::upcast_impl(x, (Target*)0);
}
template <class Target, class Source>
inline Target* downcast(Source* x, Target* = 0)
{
detail::assert_castable<Source>();
detail::assert_castable<Target>();
return detail::downcast<Target>(x, detail::convertible<Source*>::check((Target*)0));
}
}} // namespace boost::python
#endif // CAST_DWA200269_HPP
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