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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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