// 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/type_traits/same_traits.hpp> | |
# include <boost/type_traits/cv_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)]; | |
} | |
template <class Source, class Target> | |
inline Target* upcast_impl(Source* x, Target*) | |
{ | |
typedef typename add_cv<Source>::type src_t; | |
typedef typename add_cv<Target>::type target_t; | |
bool const same = 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 |